TY - JOUR
T1 - A hybrid optimization grey model based on segmented gra and multi-strategy contest for short-term power load forecasting
AU - Min, Jin
AU - Xiang, Zhou
AU - Zhiming, Zhang
AU - Tentzeris, Manos M.
PY - 2012
Y1 - 2012
N2 - In this paper, a hybrid grey model with both internal and external optimization is proposed to forecast the short-term power load which has the characteristics of nonlinear fluctuation and random growth. The internal optimization consists of modeling feasibility test and parameter a correction. The external optimization includes three aspects. First, the original series are selected from different viewpoints to construct different forecasting strategies. Second, the predicted day is divided into several smooth segments for separate forecasting. Finally, the different forecasting strategies are implemented respectively in the different segments through grey correlation contest. A practical application verifies that the proposed model has a higher forecasting accuracy and the independency on the choice of initial value.
AB - In this paper, a hybrid grey model with both internal and external optimization is proposed to forecast the short-term power load which has the characteristics of nonlinear fluctuation and random growth. The internal optimization consists of modeling feasibility test and parameter a correction. The external optimization includes three aspects. First, the original series are selected from different viewpoints to construct different forecasting strategies. Second, the predicted day is divided into several smooth segments for separate forecasting. Finally, the different forecasting strategies are implemented respectively in the different segments through grey correlation contest. A practical application verifies that the proposed model has a higher forecasting accuracy and the independency on the choice of initial value.
KW - External optimization
KW - Hybrid grey model
KW - Multi-strategy contest
KW - Parameter a correction
KW - Segmented grey correlation
KW - Short-term power load forecasting
UR - http://www.scopus.com/inward/record.url?scp=84858229525&partnerID=8YFLogxK
M3 - Article
VL - 24
SP - 15
EP - 28
JO - JOURNAL OF GREY SYSTEM
JF - JOURNAL OF GREY SYSTEM
SN - 0957-3720
IS - 1
ER -
TY - JOUR
T1 - Approximate Controllability for Navier–Stokes Equations in 3D Rectangles Under Lions Boundary Conditions
AU - Phan, Duy
AU - Rodrigues, Sérgio S.
PY - 2019/7
Y1 - 2019/7
N2 - The 3D Navier–Stokes system, under Lions boundary conditions, is proven to be approximately controllable provided a suitable saturating set does exist. An explicit saturating set for 3D rectangles is given.
AB - The 3D Navier–Stokes system, under Lions boundary conditions, is proven to be approximately controllable provided a suitable saturating set does exist. An explicit saturating set for 3D rectangles is given.
KW - Approximate controllability
KW - Navier–Stokes equations
KW - Saturating set
U2 - 10.1007/s10883-018-9412-0
DO - 10.1007/s10883-018-9412-0
M3 - Article
VL - 25
SP - 351
EP - 376
JO - Journal of Dynamical and Control Systems
JF - Journal of Dynamical and Control Systems
SN - 1079-2724
IS - 3
ER -
TY - JOUR
T1 - Asymptotics for infinite systems of differential equations
AU - Paunonen, Lassi
AU - Seifert, David
PY - 2017
Y1 - 2017
N2 - This paper investigates the asymptotic behavior of solutions to certain infinite systems of ordinary differential equations. In particular, we use results from ergodic theory and the asymptotic theory of C0-semigroups to obtain a characterization, in terms of convergence of certain Cesàro averages, of those initial values which lead to convergent solutions. Moreover, we obtain estimates on the rate of convergence for solutions whose initial values satisfy a stronger ergodic condition. These results rely on a detailed spectral analysis of the operator describing the system, which is made possible by certain structural assumptions on the operator. The resulting class of systems is sufficiently broad to cover a number of important applications including, in particular, both the so-called robot rendezvous problem and an important class of platoon systems arising in control theory. Our method leads to new results in both cases.
AB - This paper investigates the asymptotic behavior of solutions to certain infinite systems of ordinary differential equations. In particular, we use results from ergodic theory and the asymptotic theory of C0-semigroups to obtain a characterization, in terms of convergence of certain Cesàro averages, of those initial values which lead to convergent solutions. Moreover, we obtain estimates on the rate of convergence for solutions whose initial values satisfy a stronger ergodic condition. These results rely on a detailed spectral analysis of the operator describing the system, which is made possible by certain structural assumptions on the operator. The resulting class of systems is sufficiently broad to cover a number of important applications including, in particular, both the so-called robot rendezvous problem and an important class of platoon systems arising in control theory. Our method leads to new results in both cases.
KW - Asymptotic behavior
KW - C0-semigroup
KW - Ergodic theory
KW - Ordinary differential equations
KW - Rates of convergence
KW - Spectrum
KW - System
U2 - 10.1137/15M1051993
DO - 10.1137/15M1051993
M3 - Article
VL - 55
SP - 1153
EP - 1178
JO - SIAM Journal on Control and Optimization
JF - SIAM Journal on Control and Optimization
SN - 0363-0129
IS - 2
ER -
TY - JOUR
T1 - Customized dimensional analysis conceptual modelling framework for design optimization—a case study on the cross-flow micro turbine model
AU - Woldemariam, Endashaw Tesfaye
AU - Coatanéa, Eric
AU - Wang, G. Gary
AU - Lemu, Hirpa G.
AU - Wu, Di
PY - 2019
Y1 - 2019
N2 - Dimensional Analysis Conceptual Modelling (DACM) is a framework used for conceptual modelling and simulation in system and product designs. The framework is based on cause–effect analysis between variables and functions in a problem. This article presents an approach that mobilizes concepts from the DACM framework to assist solve high-dimensional expensive optimization problems with lower computational costs. The latter fundamentally utilizes theories and concepts from well-practised dimensional analysis, functional modelling and bond graphing. Statistical design-of-experiments theory is also utilized in the framework to measure impact levels of variables towards the objective. Simplifying as well as decomposing followed by optimization of expensive problems are the focuses of the article. To illustrate the approach, a case study on the performance optimization of a cross-flow micro hydro turbine is presented. The customized DACM framework assisted optimization approach converges faster and returns better results than the one without. A single-step simplification approach is employed in the case study and it returns a better average optimization result with about only one fifth of the function evaluations compared to optimization using the original model.
AB - Dimensional Analysis Conceptual Modelling (DACM) is a framework used for conceptual modelling and simulation in system and product designs. The framework is based on cause–effect analysis between variables and functions in a problem. This article presents an approach that mobilizes concepts from the DACM framework to assist solve high-dimensional expensive optimization problems with lower computational costs. The latter fundamentally utilizes theories and concepts from well-practised dimensional analysis, functional modelling and bond graphing. Statistical design-of-experiments theory is also utilized in the framework to measure impact levels of variables towards the objective. Simplifying as well as decomposing followed by optimization of expensive problems are the focuses of the article. To illustrate the approach, a case study on the performance optimization of a cross-flow micro hydro turbine is presented. The customized DACM framework assisted optimization approach converges faster and returns better results than the one without. A single-step simplification approach is employed in the case study and it returns a better average optimization result with about only one fifth of the function evaluations compared to optimization using the original model.
KW - Causality analysis
KW - conceptual modelling
KW - DACM assisted optimization
KW - high-dimensional optimization
KW - micro cross-flow turbine
U2 - 10.1080/0305215X.2018.1519556
DO - 10.1080/0305215X.2018.1519556
M3 - Article
VL - 51
SP - 1168
EP - 1184
JO - Engineering Optimization
JF - Engineering Optimization
SN - 0305-215X
IS - 7
ER -
TY - JOUR
T1 - Direct fixed-step maximum power point tracking algorithms with adaptive perturbation frequency
AU - Amer, Eyal
AU - Kuperman, Alon
AU - Suntio, Teuvo
PY - 2019/1/27
Y1 - 2019/1/27
N2 - Owing to the good trade-off between implementation and performance, fixed-step direct maximum power point tracking techniques (e.g., perturb and observe and incremental conductance algorithms) have gained popularity over the years. In order to optimize their performance, perturbation frequency and perturbation step size are usually determined a priori. While the first mentioned design parameter is typically dictated by the worst-case settling time of the combined energy conversion system, the latter must be high enough to both differentiate the system response from that caused by irradiation variation and match the finite resolution of the analog-to-digital converter in case of digital implementation. Well-established design guidelines, however, aim to optimize steady-state algorithm performance while leaving transients nearly untreated. To improve transient behavior while keeping the steady-state operation unaltered, variable step direct maximum power point tracking algorithms based on adaptive perturbation step size were proposed. This paper proposes a concept of utilizing adaptive perturbation frequency rather than variable step size, based on recently revised guidelines for designing fixed-step direct maximum power point tracking techniques. Preliminary results demonstrate the superiority of the proposed method over adaptive perturbation step size operation during transients, without compromising the steady state performance.
AB - Owing to the good trade-off between implementation and performance, fixed-step direct maximum power point tracking techniques (e.g., perturb and observe and incremental conductance algorithms) have gained popularity over the years. In order to optimize their performance, perturbation frequency and perturbation step size are usually determined a priori. While the first mentioned design parameter is typically dictated by the worst-case settling time of the combined energy conversion system, the latter must be high enough to both differentiate the system response from that caused by irradiation variation and match the finite resolution of the analog-to-digital converter in case of digital implementation. Well-established design guidelines, however, aim to optimize steady-state algorithm performance while leaving transients nearly untreated. To improve transient behavior while keeping the steady-state operation unaltered, variable step direct maximum power point tracking algorithms based on adaptive perturbation step size were proposed. This paper proposes a concept of utilizing adaptive perturbation frequency rather than variable step size, based on recently revised guidelines for designing fixed-step direct maximum power point tracking techniques. Preliminary results demonstrate the superiority of the proposed method over adaptive perturbation step size operation during transients, without compromising the steady state performance.
KW - Maximum power point tracking
KW - Perturbation frequency
KW - Photovoltaic generators
KW - Step size
U2 - 10.3390/en12030399
DO - 10.3390/en12030399
M3 - Article
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 3
M1 - 399
ER -
TY - JOUR
T1 - Frequency domain robust regulation of signals generated by an infinite-dimensional exosystem
AU - Laakkonen, Petteri
AU - Pohjolainen, Seppo
PY - 2015
Y1 - 2015
N2 - This paper deals with frequency domain robust regulation of signals generated by an infinite-dimensional exosystem. The problem is formulated and the stability types are chosen so that one can generalize the existing finite-dimensional theory to more general classes of infinite-dimensional systems and signals. The main results of this article are extensions of the internal model principle, of a necessary and sufficient solvability condition for the robust regulation problem, and of Davison's simple servo compensator for stable plants in the chosen algebraic framework.
AB - This paper deals with frequency domain robust regulation of signals generated by an infinite-dimensional exosystem. The problem is formulated and the stability types are chosen so that one can generalize the existing finite-dimensional theory to more general classes of infinite-dimensional systems and signals. The main results of this article are extensions of the internal model principle, of a necessary and sufficient solvability condition for the robust regulation problem, and of Davison's simple servo compensator for stable plants in the chosen algebraic framework.
KW - Frequency domain
KW - Infinite-dimensional exosystems
KW - Infinite-dimensional systems
KW - Internal model
KW - Robust regulation
UR - http://www.scopus.com/inward/record.url?scp=84923923144&partnerID=8YFLogxK
U2 - 10.1137/130950057
DO - 10.1137/130950057
M3 - Article
VL - 53
SP - 139
EP - 166
JO - SIAM Journal on Control and Optimization
JF - SIAM Journal on Control and Optimization
SN - 0363-0129
IS - 1
ER -
TY - JOUR
T1 - Identification of three-phase grid impedance in the presence of parallel converters
AU - Luhtala, Roni
AU - Messo, Tuomas
AU - Roinila, Tomi
AU - Alenius, Henrik
AU - Jong, Erik De
AU - Burstein, Andrew
AU - Fabian, Alejandra
PY - 2019
Y1 - 2019
N2 - Grid impedance is an important parameter which affects the control performance of grid-connected power converters. Several methods already exist for optimizing the converter control system based on knowledge of grid impedance value. Grid impedance may change rapidly due to fault or disconnection of a transmission line. Therefore, online grid identification methods have been recently proposed to have up-to-date information about the grid impedance value. This is usually done by perturbing the converter output current and measuring the response in output voltage. However, any parallel converters connected to the same interface point will cause errors, since the measured current differs from the current that is flowing through the grid interface point. This paper points out challenges and errors in grid impedance identification, caused by parallel converters and their internal control functions, such as grid-voltage support. Experimental grid-impedance measurements are shown from the power hardware-in-the-loop setup developed at DNV-GL Flexible Power Grid Lab.
AB - Grid impedance is an important parameter which affects the control performance of grid-connected power converters. Several methods already exist for optimizing the converter control system based on knowledge of grid impedance value. Grid impedance may change rapidly due to fault or disconnection of a transmission line. Therefore, online grid identification methods have been recently proposed to have up-to-date information about the grid impedance value. This is usually done by perturbing the converter output current and measuring the response in output voltage. However, any parallel converters connected to the same interface point will cause errors, since the measured current differs from the current that is flowing through the grid interface point. This paper points out challenges and errors in grid impedance identification, caused by parallel converters and their internal control functions, such as grid-voltage support. Experimental grid-impedance measurements are shown from the power hardware-in-the-loop setup developed at DNV-GL Flexible Power Grid Lab.
KW - DC–AC power converters
KW - Grid impedance identification
KW - Power hardware-in-the-loop
U2 - 10.3390/en12142674
DO - 10.3390/en12142674
M3 - Article
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 14
M1 - 2674
ER -
TY - JOUR
T1 - Maximum perturbation step size in MPP-Tracking control for ensuring predicted PV power settling behavior
AU - Suntio, Teuvo
AU - Kuperman, Alon
PY - 2019/10/19
Y1 - 2019/10/19
N2 - The heuristic perturb-and-observe-based maximum-power-point tracking (MPPT) algorithm of photovoltaic (PV) generator is still the most popular technique in use, despite the broad spectrum of developed other MPPT algorithms. The correct direction of the next perturbation step requires that the previous perturbation is settled down properly and the applied perturbation step size is large enough to overcome the PV-power changes induced by the varying irradiation level and/or the power-grid-originated PV-voltage ripple. The requirements for the minimum perturbation step size are well defined in the available literature. The design equations to predict the PV-power settling time are derived by assuming that the PV-interfacing converter operates in continuous conduction mode (CCM). A large perturbation step size may drive the interfacing converter to enter into discontinuous conduction mode (DCM), which will delay the PV-power settling process and destroy the validity of the predicted settling times. In order to avoid confusing the MPPT process, the maximum perturbation step size has to be limited as well. This paper provides theoretical foundations for the proper design of the maximum step size based on the DC-DC interfacing-converter dynamic behavior. The theoretical findings are validated with experiments as well as by simulations by means of a boost-type DC-DC converter and real PV panel.
AB - The heuristic perturb-and-observe-based maximum-power-point tracking (MPPT) algorithm of photovoltaic (PV) generator is still the most popular technique in use, despite the broad spectrum of developed other MPPT algorithms. The correct direction of the next perturbation step requires that the previous perturbation is settled down properly and the applied perturbation step size is large enough to overcome the PV-power changes induced by the varying irradiation level and/or the power-grid-originated PV-voltage ripple. The requirements for the minimum perturbation step size are well defined in the available literature. The design equations to predict the PV-power settling time are derived by assuming that the PV-interfacing converter operates in continuous conduction mode (CCM). A large perturbation step size may drive the interfacing converter to enter into discontinuous conduction mode (DCM), which will delay the PV-power settling process and destroy the validity of the predicted settling times. In order to avoid confusing the MPPT process, the maximum perturbation step size has to be limited as well. This paper provides theoretical foundations for the proper design of the maximum step size based on the DC-DC interfacing-converter dynamic behavior. The theoretical findings are validated with experiments as well as by simulations by means of a boost-type DC-DC converter and real PV panel.
KW - MPP tracking
KW - Perturbation step size
KW - PV generator
KW - Transient settling time
U2 - 10.3390/en12203984
DO - 10.3390/en12203984
M3 - Article
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 20
M1 - 3984
ER -
TY - JOUR
T1 - Mixed-integer linear programming approach for global discrete sizing optimization of frame structures
AU - van Mellaert, R.
AU - Mela, K.
AU - Tiainen, T.
AU - Heinisuo, M.
AU - Lombaert, G.
AU - Schevenels, M.
PY - 2018
Y1 - 2018
N2 - This paper focuses on discrete sizing optimization of frame structures using commercial profile catalogs. The optimization problem is formulated as a mixed-integer linear programming (MILP) problem by including the equations of structural analysis as constraints. The internal forces of the members are taken as continuous state variables. Binary variables are used for choosing the member profiles from a catalog. Both the displacement and stress constraints are formulated such that for each member limit values can be imposed at predefined locations along the member. A valuable feature of the formulation, lacking in most contemporary approaches, is that global optimality of the solution is guaranteed by solving the MILP using branch-and-bound techniques. The method is applied to three design problems: a portal frame, a two-story frame with three load cases and a multiple-bay multiple-story frame. Performance profiles are determined to compare the MILP reformulation method with a genetic algorithm.
AB - This paper focuses on discrete sizing optimization of frame structures using commercial profile catalogs. The optimization problem is formulated as a mixed-integer linear programming (MILP) problem by including the equations of structural analysis as constraints. The internal forces of the members are taken as continuous state variables. Binary variables are used for choosing the member profiles from a catalog. Both the displacement and stress constraints are formulated such that for each member limit values can be imposed at predefined locations along the member. A valuable feature of the formulation, lacking in most contemporary approaches, is that global optimality of the solution is guaranteed by solving the MILP using branch-and-bound techniques. The method is applied to three design problems: a portal frame, a two-story frame with three load cases and a multiple-bay multiple-story frame. Performance profiles are determined to compare the MILP reformulation method with a genetic algorithm.
KW - Discrete optimization
KW - Frame structures
KW - Global optimization
KW - Mixed-integer linear programming
KW - Sizing optimization
U2 - 10.1007/s00158-017-1770-9
DO - 10.1007/s00158-017-1770-9
M3 - Article
VL - 57
SP - 579
EP - 593
JO - Structural and Multidisciplinary Optimization
JF - Structural and Multidisciplinary Optimization
SN - 1615-147X
IS - 2
ER -
TY - JOUR
T1 - On the complexity of restoring corrupted colorings
AU - De Biasi, Marzio
AU - Lauri, Juho
PY - 2019/5
Y1 - 2019/5
N2 - In the r-Fix problem, we are given a graph G, a (non-proper) vertex-coloring c: V(G) → [r] , and a positive integer k. The goal is to decide whether a proper r-coloring c′ is obtainable from c by recoloring at most k vertices of G. Recently, Junosza-Szaniawski et al. (in: SOFSEM 2015: theory and practice of computer science, Springer, Berlin, 2015) asked whether the problem has a polynomial kernel parameterized by the number of recolorings k. In a full version of the manuscript, the authors together with Garnero and Montealegre, answered the question in the negative: for every r≥ 3 , the problem r-Fix does not admit a polynomial kernel unless [InlineEquation not available: see fulltext.]. Independently of their work, we give an alternative proof of the theorem. Furthermore, we study the complexity of r-Swap, where the only difference from r-Fix is that instead of k recolorings we have a budget of k color swaps. We show that for every r≥ 3 , the problem r-Swap is [InlineEquation not available: see fulltext.]-hard whereas r-Fix is known to be FPT. Moreover, when r is part of the input, we observe both Fix and Swap are [InlineEquation not available: see fulltext.]-hard parameterized by the treewidth of the input graph. We also study promise variants of the problems, where we are guaranteed that a proper r-coloring c′ is indeed obtainable from c by some finite number of swaps. For instance, we prove that for r= 3 , the problems r-Fix-Promise and r-Swap-Promise are [InlineEquation not available: see fulltext.]-hard for planar graphs. As a consequence of our reduction, the problems cannot be solved in 2o(n) time unless the Exponential Time Hypothesis fails.
AB - In the r-Fix problem, we are given a graph G, a (non-proper) vertex-coloring c: V(G) → [r] , and a positive integer k. The goal is to decide whether a proper r-coloring c′ is obtainable from c by recoloring at most k vertices of G. Recently, Junosza-Szaniawski et al. (in: SOFSEM 2015: theory and practice of computer science, Springer, Berlin, 2015) asked whether the problem has a polynomial kernel parameterized by the number of recolorings k. In a full version of the manuscript, the authors together with Garnero and Montealegre, answered the question in the negative: for every r≥ 3 , the problem r-Fix does not admit a polynomial kernel unless [InlineEquation not available: see fulltext.]. Independently of their work, we give an alternative proof of the theorem. Furthermore, we study the complexity of r-Swap, where the only difference from r-Fix is that instead of k recolorings we have a budget of k color swaps. We show that for every r≥ 3 , the problem r-Swap is [InlineEquation not available: see fulltext.]-hard whereas r-Fix is known to be FPT. Moreover, when r is part of the input, we observe both Fix and Swap are [InlineEquation not available: see fulltext.]-hard parameterized by the treewidth of the input graph. We also study promise variants of the problems, where we are guaranteed that a proper r-coloring c′ is indeed obtainable from c by some finite number of swaps. For instance, we prove that for r= 3 , the problems r-Fix-Promise and r-Swap-Promise are [InlineEquation not available: see fulltext.]-hard for planar graphs. As a consequence of our reduction, the problems cannot be solved in 2o(n) time unless the Exponential Time Hypothesis fails.
KW - Combinatorial reconfiguration
KW - Computational complexity
KW - Graph coloring
KW - Local search
KW - Parameterized complexity
U2 - 10.1007/s10878-018-0342-2
DO - 10.1007/s10878-018-0342-2
M3 - Article
VL - 37
SP - 1150
EP - 1169
JO - Journal of Combinatorial Optimization
JF - Journal of Combinatorial Optimization
SN - 1382-6905
IS - 4
ER -
TY - JOUR
T1 - Robust controllers for regular linear systems with infinite-dimensional exosystems
AU - Paunonen, Lassi
PY - 2017
Y1 - 2017
N2 - We construct two error feedback controllers for robust output tracking and disturbance rejection of a regular linear system with nonsmooth reference and disturbance signals. We show that for sufficiently smooth signals the output converges to the reference at a rate that depends on the behavior of the transfer function of the plant on the imaginary axis. In addition, we construct a controller that can be designed to achieve robustness with respect to a given class of uncertainties in the system, and we present a novel controller structure for output tracking and disturbance rejection without the robustness requirement. We also generalize the internal model principle for regular linear systems with boundary disturbance and for controllers with unbounded input and output operators. The construction of controllers is illustrated with an example where we consider output tracking of a nonsmooth periodic reference signal for a two-dimensional heat equation with boundary control and observation, and with periodic disturbances on the boundary.
AB - We construct two error feedback controllers for robust output tracking and disturbance rejection of a regular linear system with nonsmooth reference and disturbance signals. We show that for sufficiently smooth signals the output converges to the reference at a rate that depends on the behavior of the transfer function of the plant on the imaginary axis. In addition, we construct a controller that can be designed to achieve robustness with respect to a given class of uncertainties in the system, and we present a novel controller structure for output tracking and disturbance rejection without the robustness requirement. We also generalize the internal model principle for regular linear systems with boundary disturbance and for controllers with unbounded input and output operators. The construction of controllers is illustrated with an example where we consider output tracking of a nonsmooth periodic reference signal for a two-dimensional heat equation with boundary control and observation, and with periodic disturbances on the boundary.
KW - Controller Design
KW - Feedback
KW - Regular Linear Systems
KW - Robust Output Regulation
KW - Stability
U2 - 10.1137/16M107181X
DO - 10.1137/16M107181X
M3 - Article
VL - 55
SP - 1567
EP - 1597
JO - SIAM Journal on Control and Optimization
JF - SIAM Journal on Control and Optimization
SN - 0363-0129
IS - 3
ER -
TY - JOUR
T1 - Secure and connected wearable intelligence for content delivery at a mass event
T2 - A case study
AU - Ometov, Aleksandr
AU - Solomitckii, Dmitrii
AU - Olsson, Thomas
AU - Bezzateev, Sergey
AU - Shchesniak, Anna
AU - Andreev, Sergey
AU - Harju, Jarmo
AU - Koucheryavy, Yevgeni
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Presently, smart and connected wearable systems, such as on-body sensors and head-mounted displays, as well as other small form factor but powerful personal computers are rapidly pervading all areas of our life. Motivated by the opportunities that next-generation wearable intelligence is expected to provide, the goal of this work is to build a comprehensive understanding around some of the user-centric security and trust aspects of the emerging wearable and close-to-body wireless systems operating in mass events and under heterogeneous conditions. The paper thus intends to bring the attention of the research community to this emerging paradigm and discuss the pressing security and connectivity challenges within a popular consumer context. Our selected target scenario is that of a sports match, where wearable-equipped users may receive their preferred data over various radio access protocols. We also propose an authentication framework that allows for delivery of the desired content securely within the considered ecosystem.
AB - Presently, smart and connected wearable systems, such as on-body sensors and head-mounted displays, as well as other small form factor but powerful personal computers are rapidly pervading all areas of our life. Motivated by the opportunities that next-generation wearable intelligence is expected to provide, the goal of this work is to build a comprehensive understanding around some of the user-centric security and trust aspects of the emerging wearable and close-to-body wireless systems operating in mass events and under heterogeneous conditions. The paper thus intends to bring the attention of the research community to this emerging paradigm and discuss the pressing security and connectivity challenges within a popular consumer context. Our selected target scenario is that of a sports match, where wearable-equipped users may receive their preferred data over various radio access protocols. We also propose an authentication framework that allows for delivery of the desired content securely within the considered ecosystem.
KW - Authentication
KW - Challenges
KW - Mass event
KW - Security
KW - Wearables
KW - WiGig
KW - Wireless
U2 - 10.3390/jsan6020005
DO - 10.3390/jsan6020005
M3 - Article
VL - 6
JO - Journal of Sensor and Actuator Networks
JF - Journal of Sensor and Actuator Networks
SN - 2224-2708
IS - 2
M1 - 5
ER -
TY - JOUR
T1 - Stabilization to trajectories for parabolic equations
AU - Phan, Duy
AU - Rodrigues, Sérgio S.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Both internal and boundary feedback exponential stabilization to trajectories for semilinear parabolic equations in a given bounded domain are addressed. The values of the controls are linear combinations of a finite number of actuators which are supported in a small region. A condition on the family of actuators is given which guarantees the local stabilizability of the control system. It is shown that a linearization-based Riccati feedback stabilizing controller can be constructed. The results of numerical simulations are presented and discussed.
AB - Both internal and boundary feedback exponential stabilization to trajectories for semilinear parabolic equations in a given bounded domain are addressed. The values of the controls are linear combinations of a finite number of actuators which are supported in a small region. A condition on the family of actuators is given which guarantees the local stabilizability of the control system. It is shown that a linearization-based Riccati feedback stabilizing controller can be constructed. The results of numerical simulations are presented and discussed.
KW - Feedback stabilization to trajectories
KW - Semilinear parabolic equations
U2 - 10.1007/s00498-018-0218-0
DO - 10.1007/s00498-018-0218-0
M3 - Article
VL - 30
JO - Mathematics of Control Signals and Systems
JF - Mathematics of Control Signals and Systems
SN - 0932-4194
IS - 2
M1 - 11
ER -
TY - JOUR
T1 - Towards the EU emission targets of 2050
T2 - Cost-effective emission reduction in Finnish detached houses
AU - Hirvonen, Janne
AU - Jokisalo, Juha
AU - Heljo, Juhani
AU - Kosonen, Risto
PY - 2019/11/19
Y1 - 2019/11/19
N2 - To mitigate the effects of climate change, the European Union calls for major carbon emission reductions in the building sector through a deep renovation of the existing building stock. This study examines the cost-effective energy retrofit measures in Finnish detached houses. The Finnish detached house building stock was divided into four age classes according to the building code in effect at the time of their construction. Multi-objective optimization with a genetic algorithm was used to minimize the life cycle cost and CO2 emissions in each building type for five different main heating systems (district heating, wood/oil boiler, direct electric heating, and ground-source heat pump) by improving the building envelope and systems. Cost-effective emission reductions were possible with all heating systems, but especially with ground-source heat pumps. Replacing oil boilers with ground-source heat pumps (GSHPs), emissions could be reduced by 79% to 92% across all the studied detached houses and investment levels. With all the other heating systems, emission reductions of 20% to 75% were possible. The most cost-effective individual renovation measures were the installation of air-to-air heat pumps for auxiliary heating and improving the thermal insulation of external walls.
AB - To mitigate the effects of climate change, the European Union calls for major carbon emission reductions in the building sector through a deep renovation of the existing building stock. This study examines the cost-effective energy retrofit measures in Finnish detached houses. The Finnish detached house building stock was divided into four age classes according to the building code in effect at the time of their construction. Multi-objective optimization with a genetic algorithm was used to minimize the life cycle cost and CO2 emissions in each building type for five different main heating systems (district heating, wood/oil boiler, direct electric heating, and ground-source heat pump) by improving the building envelope and systems. Cost-effective emission reductions were possible with all heating systems, but especially with ground-source heat pumps. Replacing oil boilers with ground-source heat pumps (GSHPs), emissions could be reduced by 79% to 92% across all the studied detached houses and investment levels. With all the other heating systems, emission reductions of 20% to 75% were possible. The most cost-effective individual renovation measures were the installation of air-to-air heat pumps for auxiliary heating and improving the thermal insulation of external walls.
KW - Deep renovation
KW - Detached house
KW - Energy retrofit
KW - Genetic algorithm
KW - Greenhouse gas emissions
KW - Heat pump
KW - Multi-objective optimization
U2 - 10.3390/en12224395
DO - 10.3390/en12224395
M3 - Article
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 22
M1 - 4395
ER -
TY - JOUR
T1 - Impedance-based interactions in grid-tied three-phase inverters in renewable energy applications
AU - Suntio, Teuvo
AU - Messo, Tuomas
AU - Berg, Matias
AU - Alenius, Henrik
AU - Reinikka, Tommi
AU - Luhtala, Roni
AU - Zenger, Kai
PY - 2019/1/31
Y1 - 2019/1/31
N2 - Impedance-ratio-based interaction analyses in terms of stability and performance of DC-DC converters is well established. Similar methods are applied to grid-connected three-phase converters as well, but the multivariable nature of the converters and the grid makes these analyses very complex. This paper surveys the state of the interaction analyses in the grid-connected three-phase converters, which are used in renewable-energy applications. The surveys show clearly that the impedance-ratio-based stability assessment are usually performed neglecting the cross-couplings between the impedance elements for reducing the complexity of the analyses. In addition, the interactions, which affect the transient performance, are not treated usually at all due to the missing of the corresponding analytic formulations. This paper introduces the missing formulations as well as explicitly showing that the cross-couplings of the impedance elements have to be taken into account for the stability assessment to be valid. In addition, this paper shows that the most accurate stability information can be obtained by means of the determinant related to the associated multivariable impedance ratio. The theoretical findings are also validated by extensive experimental measurements.
AB - Impedance-ratio-based interaction analyses in terms of stability and performance of DC-DC converters is well established. Similar methods are applied to grid-connected three-phase converters as well, but the multivariable nature of the converters and the grid makes these analyses very complex. This paper surveys the state of the interaction analyses in the grid-connected three-phase converters, which are used in renewable-energy applications. The surveys show clearly that the impedance-ratio-based stability assessment are usually performed neglecting the cross-couplings between the impedance elements for reducing the complexity of the analyses. In addition, the interactions, which affect the transient performance, are not treated usually at all due to the missing of the corresponding analytic formulations. This paper introduces the missing formulations as well as explicitly showing that the cross-couplings of the impedance elements have to be taken into account for the stability assessment to be valid. In addition, this paper shows that the most accurate stability information can be obtained by means of the determinant related to the associated multivariable impedance ratio. The theoretical findings are also validated by extensive experimental measurements.
KW - Grid synchronization
KW - Power electronics
KW - Power grid
KW - Source and load impedance
KW - Stability
KW - Transient dynamics
UR - http://www.scopus.com/inward/record.url?scp=85060952873&partnerID=8YFLogxK
U2 - 10.3390/en12030464
DO - 10.3390/en12030464
M3 - Review Article
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 3
M1 - 464
ER -
TY - JOUR
T1 - Power electronics in renewable energy systems
AU - Suntio, Teuvo
AU - Messo, Tuomas
PY - 2019
Y1 - 2019
U2 - 10.3390/en12101852
DO - 10.3390/en12101852
M3 - Editorial
VL - 12
JO - Energies
JF - Energies
SN - 1996-1073
IS - 10
M1 - en12101852
ER -
TY - CHAP
T1 - A Real-Time Big Data Control-Theoretical Framework for Cyber-Physical-Human Systems
AU - Gusrialdi, Azwirman
AU - Xu, Ying
AU - Qu, Zhihua
AU - Simaan, Marwan A.
PY - 2019
Y1 - 2019
N2 - Cyber-physical-human systems naturally arise from interdependent infrastructure systems and smart connected communities. Such applications require ubiquitous information sensing and processing, intelligent machine-to-machine communication for a seamless coordination, as well as intelligent interactions between humans and machines. This chapter presents a control-theoretical framework to model heterogeneous physical dynamic systems, information and communication, as well as cooperative controls and/or distributed optimization of such interconnected systems. It is shown that efficient analytical and computational algorithms can be modularly designed and hierarchically implemented to operate and optimize cyber-physical-human systems, first to quantify individually the input–output relationship of nonlinear dynamic behaviors of every physical subsystem, then to coordinate locally both cyber-physical interactions of neighboring agents as well as physical-human interactions, and finally to dynamically model and optimize the overall networked system. The hierarchical structure makes the overall optimization and control problem scalable and solvable. Moreover, the three levels integrate individual designs and optimization, distributed cooperative optimization, and decision-making through real-time, data-driven, model-based learning and control. Specifically, one of the contributions of the chapter is to demonstrate how the combination of dissipativity theory and cooperative control serves as a natural framework and promising tools to analyze, optimize, and control such large-scale system. Application to digital power grid is investigated as an illustrative example.
AB - Cyber-physical-human systems naturally arise from interdependent infrastructure systems and smart connected communities. Such applications require ubiquitous information sensing and processing, intelligent machine-to-machine communication for a seamless coordination, as well as intelligent interactions between humans and machines. This chapter presents a control-theoretical framework to model heterogeneous physical dynamic systems, information and communication, as well as cooperative controls and/or distributed optimization of such interconnected systems. It is shown that efficient analytical and computational algorithms can be modularly designed and hierarchically implemented to operate and optimize cyber-physical-human systems, first to quantify individually the input–output relationship of nonlinear dynamic behaviors of every physical subsystem, then to coordinate locally both cyber-physical interactions of neighboring agents as well as physical-human interactions, and finally to dynamically model and optimize the overall networked system. The hierarchical structure makes the overall optimization and control problem scalable and solvable. Moreover, the three levels integrate individual designs and optimization, distributed cooperative optimization, and decision-making through real-time, data-driven, model-based learning and control. Specifically, one of the contributions of the chapter is to demonstrate how the combination of dissipativity theory and cooperative control serves as a natural framework and promising tools to analyze, optimize, and control such large-scale system. Application to digital power grid is investigated as an illustrative example.
U2 - 10.1007/978-3-030-25446-9_7
DO - 10.1007/978-3-030-25446-9_7
M3 - Chapter
SN - 978-3-030-25445-2
T3 - Springer Optimization and Its Applications
SP - 149
EP - 172
BT - Computational Intelligence and Optimization Methods for Control Engineering
PB - Springer International Publishing
ER -
TY - CHAP
T1 - Towards dependable automation
AU - Seppälä, Jari
AU - Salmenperä, Mikko
PY - 2015
Y1 - 2015
N2 - Automation runs the modern society and it’s critical systems. It is anetworked software product depending on the co-operation of old and new technologies.Information security for automation systems should be regarded in light ofthe most important quality required from automation—dependability. This chapterfocuses on process of developing dependable solutions for the entire lifecycle ofautomation systems. The approach includes a guideline for securing automation anda dependability model that is a data flow model extended with security and automationrequirements. Results of this analysis should be used in final requirementspecification for implementation. Dependability model is the key tool in securedevelopment lifecycle. It can be used in new product development, improving anold automation system and also during the active lifecycle of automation to manage inevitable changes occurring during the entire lifespan of automation system.
AB - Automation runs the modern society and it’s critical systems. It is anetworked software product depending on the co-operation of old and new technologies.Information security for automation systems should be regarded in light ofthe most important quality required from automation—dependability. This chapterfocuses on process of developing dependable solutions for the entire lifecycle ofautomation systems. The approach includes a guideline for securing automation anda dependability model that is a data flow model extended with security and automationrequirements. Results of this analysis should be used in final requirementspecification for implementation. Dependability model is the key tool in securedevelopment lifecycle. It can be used in new product development, improving anold automation system and also during the active lifecycle of automation to manage inevitable changes occurring during the entire lifespan of automation system.
UR - http://www.scopus.com/inward/record.url?scp=84934873164&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-18302-2_15
DO - 10.1007/978-3-319-18302-2_15
M3 - Chapter
SN - 978-3-319-18301-5
T3 - Intelligent Systems, Control and Automation: Science and Engineering
SP - 229
EP - 249
BT - Cyber Security: Analytics, Technology and Automation
PB - Springer International Publishing
ER -
TY - GEN
T1 - Analysis of differentially modulated cooperative communications over asymmetric fading channels
AU - Almaeeni, Sara
AU - Sofotasios, Paschalis C.
AU - Muhaidat, Sami
AU - Karagiannidis, George K.
PY - 2018/5/16
Y1 - 2018/5/16
N2 - Differential modulation has largely re-attracted the attention of academia and industry due to its advantages relating to simple implementation and no need for knowledge of channel state information. The present work analyzes the average bit error rate performance of dual-hop cooperative systems over generalized multipath fading conditions. The considered system is differentially modulated and is assumed to operate based on the amplify-and-forward relaying protocol. Therefore, the main advantage of the considered set up is that it does not require any channel state information neither at the relay nor at the destination nodes. Novel closed-form expressions are derived for the end-to-end error rate under asymmetric generalized multipath fading conditions, which are encountered in realistic wireless communication scenarios. These expressions are subsequently employed in quantifying the effect of generalized fading conditions on the achieved bit error rate performance. It is shown that the impact of multipath fading and shadowing effects is detrimental at both high and low signal-to-noise ratio regimes as the corresponding deviations are often close to an order of magnitude. The incurred difference is also significantly different than the conventional Rayleigh fading conditions, which verifies that accurate channel characterization is of paramount importance in the effective design of conventional and emerging wireless technologies. In addition, it indicates that differential modulation can be a suitable modulation scheme for relay systems, under certain conditions, since it can provide adequate performance at a reduced implementation complexity.
AB - Differential modulation has largely re-attracted the attention of academia and industry due to its advantages relating to simple implementation and no need for knowledge of channel state information. The present work analyzes the average bit error rate performance of dual-hop cooperative systems over generalized multipath fading conditions. The considered system is differentially modulated and is assumed to operate based on the amplify-and-forward relaying protocol. Therefore, the main advantage of the considered set up is that it does not require any channel state information neither at the relay nor at the destination nodes. Novel closed-form expressions are derived for the end-to-end error rate under asymmetric generalized multipath fading conditions, which are encountered in realistic wireless communication scenarios. These expressions are subsequently employed in quantifying the effect of generalized fading conditions on the achieved bit error rate performance. It is shown that the impact of multipath fading and shadowing effects is detrimental at both high and low signal-to-noise ratio regimes as the corresponding deviations are often close to an order of magnitude. The incurred difference is also significantly different than the conventional Rayleigh fading conditions, which verifies that accurate channel characterization is of paramount importance in the effective design of conventional and emerging wireless technologies. In addition, it indicates that differential modulation can be a suitable modulation scheme for relay systems, under certain conditions, since it can provide adequate performance at a reduced implementation complexity.
U2 - 10.1109/COMMNET.2018.8360284
DO - 10.1109/COMMNET.2018.8360284
M3 - Conference contribution
SP - 1
EP - 8
BT - Proceedings - 2018 International Conference on Advanced Communication Technologies and Networking, CommNet 2018
PB - IEEE
ER -
TY - GEN
T1 - An approach for implementing key performance indicators of a discrete manufacturing simulator based on the ISO 22400 standard
AU - Muhammad, Usman
AU - Ferrer, Borja Ramis
AU - Mohammed, Wael M.
AU - Lastra, Jose L.Martinez
N1 - EXT="Muhammad, Usman"
PY - 2018/6/15
Y1 - 2018/6/15
N2 - Performance measurement tools and techniques have become very significant in today's industries for increasing the efficiency of their processes in order to face the competitive market. The first step towards performance measurement is the real-time monitoring and gathering of the data from the manufacturing system. Applying these performance measurement techniques on real-world industry in a way that is more general and efficient is the next challenge. This paper presents a methodology for implementing the key performance indicators defined in the ISO 22400 standard-Automation systems and integration, Key performance indicators (KPIs) for manufacturing operations management. The proposed methodology is implemented on a multi robot line simulator for measuring its performance at runtime. The approach implements a knowledge-based system within an ontology model which describes the environment, the system and the KPIs. In fact, the KPIs semantic descriptions are based on the data models presented in the Key Performance Indicators Markup Language (KPIML), which is an XML implementation of models developed by the Manufacturing Enterprise Solutions Association (MESA) international organization.
AB - Performance measurement tools and techniques have become very significant in today's industries for increasing the efficiency of their processes in order to face the competitive market. The first step towards performance measurement is the real-time monitoring and gathering of the data from the manufacturing system. Applying these performance measurement techniques on real-world industry in a way that is more general and efficient is the next challenge. This paper presents a methodology for implementing the key performance indicators defined in the ISO 22400 standard-Automation systems and integration, Key performance indicators (KPIs) for manufacturing operations management. The proposed methodology is implemented on a multi robot line simulator for measuring its performance at runtime. The approach implements a knowledge-based system within an ontology model which describes the environment, the system and the KPIs. In fact, the KPIs semantic descriptions are based on the data models presented in the Key Performance Indicators Markup Language (KPIML), which is an XML implementation of models developed by the Manufacturing Enterprise Solutions Association (MESA) international organization.
KW - ISO 22400 standard
KW - Key performance indicators
KW - Knowledge-based system
KW - Manufacturing systems
KW - Ontology
U2 - 10.1109/ICPHYS.2018.8390779
DO - 10.1109/ICPHYS.2018.8390779
M3 - Conference contribution
SP - 629
EP - 636
BT - 2018 IEEE Industrial Cyber-Physical Systems, ICPS 2018
PB - IEEE
ER -
TY - GEN
T1 - Asymptotic Behaviour of Platoon Systems
AU - Paunonen, Lassi
AU - Seifert, David
PY - 2016/7
Y1 - 2016/7
N2 - In this paper we study the asymptotic behaviour of various platoon-type systems using the general theory developed by the authors in a recent article. The aim is to steer an infinite number of vehicles towards a target configuration in which each vehicle has a prescribed separation from its neighbour and all vehicles are moving at a given velocity. More specifically, we study systems in which state feedback is possible, systems in which observer-based dynamic output feedback is required, and also a situation in which the control objective is modified to allow the target separations to depend on the vehicles’ velocities. We show that in the first and third cases the objective can be achieved, but that in the second case the system is unstable in the sense that the associated semigroup is not uniformly bounded. We also present some quantified results concerning the rate of convergence of the platoon to its limit state when the limit exists.
AB - In this paper we study the asymptotic behaviour of various platoon-type systems using the general theory developed by the authors in a recent article. The aim is to steer an infinite number of vehicles towards a target configuration in which each vehicle has a prescribed separation from its neighbour and all vehicles are moving at a given velocity. More specifically, we study systems in which state feedback is possible, systems in which observer-based dynamic output feedback is required, and also a situation in which the control objective is modified to allow the target separations to depend on the vehicles’ velocities. We show that in the first and third cases the objective can be achieved, but that in the second case the system is unstable in the sense that the associated semigroup is not uniformly bounded. We also present some quantified results concerning the rate of convergence of the platoon to its limit state when the limit exists.
KW - Vehicle platoon
KW - ordinary differential equations
KW - asymptotic behaviour
KW - state feedback
KW - rates of convergence
M3 - Conference contribution
SP - 830
EP - 836
BT - Proceedings of the 22nd International Symposium on Mathematical Theory of Networks and Systems
PB - University of Minnesota
ER -
TY - GEN
T1 - Automatic numerical differentiation by maximum likelihood estimation of a linear Gaussian state space model
AU - Piche, Robert
PY - 2019/6/1
Y1 - 2019/6/1
N2 - A linear Gaussian state-space smoothing algorithm is presented for off-line estimation of derivatives from a sequence of noisy measurements. The algorithm uses numerically stable square-root formulas, can handle simultaneous independent measurements and non-equally spaced abscissas, and can compute state estimates at points between the data abscissas. The state space model's parameters, including driving noise intensity, measurement variance, and initial state, are determined from the given data sequence using maximum likelihood estimation computed using an expectation maximisation iteration. In tests with synthetic biomechanics data, the algorithm is found to be more accurate compared to a widely used open source automatic numerical differentiation algorithm, especially for acceleration estimation.
AB - A linear Gaussian state-space smoothing algorithm is presented for off-line estimation of derivatives from a sequence of noisy measurements. The algorithm uses numerically stable square-root formulas, can handle simultaneous independent measurements and non-equally spaced abscissas, and can compute state estimates at points between the data abscissas. The state space model's parameters, including driving noise intensity, measurement variance, and initial state, are determined from the given data sequence using maximum likelihood estimation computed using an expectation maximisation iteration. In tests with synthetic biomechanics data, the algorithm is found to be more accurate compared to a widely used open source automatic numerical differentiation algorithm, especially for acceleration estimation.
U2 - 10.23919/ECC.2019.8795960
DO - 10.23919/ECC.2019.8795960
M3 - Conference contribution
SP - 1861
EP - 1865
BT - 2019 18th European Control Conference, ECC 2019
PB - IEEE
ER -
TY - GEN
T1 - Blockchain Technology for Smartphones and Constrained IoT Devices
T2 - A Future Perspective and Implementation
AU - Zhidanov, Konstantin
AU - Bezzateev, Sergey
AU - Afanasyeva, Alexandra
AU - Sayfullin, Mikhail
AU - Vanurin, Sergey
AU - Bardinova, Yulia
AU - Ometov, Aleksandr
N1 - EXT="Zhidanov, Konstantin"
PY - 2019/7/1
Y1 - 2019/7/1
N2 - The blockchain technology is currently penetrating different sides of modern ICT community. Most of the devices involved in blockchain-related processes are specially designed targeting only the mining aspect. At the same time, the use of wearable and mobile devices may also become a part of blockchain operation, especially during the charging time. The paper considers the possibility of using a large number of constrained devices supporting the operation of the blockchain. The utilization of such devices is expected to improve the efficiency of the system and also to attract a more substantial number of users. Authors propose a novel consensus algorithm based on a combination of Proof-of-Work (PoW), Proof-of-Activity (PoA), and Proof-of-Stake (PoS). The paper first overviews the existing strategies and further describes the developed cryptographic primitives used to build a blockchain involving mobile devices. A brief numerical evaluation of the designed system is also provided in the paper.
AB - The blockchain technology is currently penetrating different sides of modern ICT community. Most of the devices involved in blockchain-related processes are specially designed targeting only the mining aspect. At the same time, the use of wearable and mobile devices may also become a part of blockchain operation, especially during the charging time. The paper considers the possibility of using a large number of constrained devices supporting the operation of the blockchain. The utilization of such devices is expected to improve the efficiency of the system and also to attract a more substantial number of users. Authors propose a novel consensus algorithm based on a combination of Proof-of-Work (PoW), Proof-of-Activity (PoA), and Proof-of-Stake (PoS). The paper first overviews the existing strategies and further describes the developed cryptographic primitives used to build a blockchain involving mobile devices. A brief numerical evaluation of the designed system is also provided in the paper.
KW - applications
KW - blockhcain
KW - distributed systems
KW - future perspective
KW - networks
U2 - 10.1109/CBI.2019.10092
DO - 10.1109/CBI.2019.10092
M3 - Conference contribution
SP - 20
EP - 27
BT - 21st IEEE Conference on Business Informatics, CBI 2019
A2 - Becker, Jorg
A2 - Pastor, Oscar
A2 - Kornyshova, Elena
A2 - Korepanov, V. O.
A2 - Tsukanova, Olga A.
A2 - Albornoz, Judith Barrios
A2 - Fedyanin, D.
A2 - Burkov, V.N.
A2 - Nazarov, Dmitry M.
A2 - Novikov, Dmitriy
A2 - Uskenbaeva, Raisa
A2 - Shchepkin, A V.
PB - IEEE
ER -
TY - GEN
T1 - Capacity analysis under generalized composite fading conditions
AU - Sofotasios, Paschalis C.
AU - Yoo, Seong Ki
AU - Bhargav, Nidhi
AU - Muhaidat, Sami
AU - Cotton, Simon L.
AU - Matthaiou, Michail
AU - Valkama, Mikko
AU - Karagiannidis, George K.
PY - 2018/5/16
Y1 - 2018/5/16
N2 - Novel composite fading models were recently proposed based on inverse gamma distributed shadowing conditions. These models were extensively shown to provide remarkable modeling of the simultaneous occurrence of multipath fading and shadowing phenomena in emerging wireless scenarios such as cellular, off-body and vehicle-to-vehicle communications. Furthermore, the algebraic representation of these models is rather tractable, which renders them convenient to handle both analytically and numerically. The present contribution presents the major theoretical and practical characteristics of the η - μ / inverse gamma composite fading model, followed by a thorough ergodic capacity analysis. To this end, novel analytic expressions are derived, which are subsequently used in the evaluation of the corresponding system performance. In this context, the offered results are compared with respective results from cases assuming conventional fading conditions, which leads to the development of numerous insights on the effect of the multipath fading and shadowing severity on the achieved capacity levels. It is expected that these results will be useful in the design of timely and highly demanding wireless technologies, such as wearable, cellular and inter-vehicular communications as well in wireless power transfer based applications in the context of the Internet of Things.
AB - Novel composite fading models were recently proposed based on inverse gamma distributed shadowing conditions. These models were extensively shown to provide remarkable modeling of the simultaneous occurrence of multipath fading and shadowing phenomena in emerging wireless scenarios such as cellular, off-body and vehicle-to-vehicle communications. Furthermore, the algebraic representation of these models is rather tractable, which renders them convenient to handle both analytically and numerically. The present contribution presents the major theoretical and practical characteristics of the η - μ / inverse gamma composite fading model, followed by a thorough ergodic capacity analysis. To this end, novel analytic expressions are derived, which are subsequently used in the evaluation of the corresponding system performance. In this context, the offered results are compared with respective results from cases assuming conventional fading conditions, which leads to the development of numerous insights on the effect of the multipath fading and shadowing severity on the achieved capacity levels. It is expected that these results will be useful in the design of timely and highly demanding wireless technologies, such as wearable, cellular and inter-vehicular communications as well in wireless power transfer based applications in the context of the Internet of Things.
U2 - 10.1109/COMMNET.2018.8360282
DO - 10.1109/COMMNET.2018.8360282
M3 - Conference contribution
SP - 1
EP - 10
BT - Proceedings - 2018 International Conference on Advanced Communication Technologies and Networking, CommNet 2018
PB - IEEE
ER -
TY - GEN
T1 - Complete Odometry Estimation of a Vehicle Using Single Automotive Radar and a Gyroscope
AU - Ghabcheloo, Reza
AU - Siddiqui, Shadman
N1 - INT=aut,"Siddiqui, Shadman"
PY - 2018/8/20
Y1 - 2018/8/20
N2 - In this paper, we propose an algorithm for complete odometry of a vehicle on a horizontal plane., that is., estimation of linear velocity vector (forward and sideslip speeds) and angular speed of a vehicle. The vehicle is equipped with an automotive Radar sensor and a vertical gyro. The Radar sensor provides radial speed and azimuth angle of number of objects in the environment. We first derive the kinematic constraints imposed on the vehicle motion and stationary points in the environment. Using the constraints we classify the points detected by the Radar to stationary and non-stationary points. It is known that using data from a single Radar., the abovementioned constraints are singular. Previous works have thus proposed the use of more than one Radar sensor., or they have neglected the sideslip speed. In our work, we then use the Radar data of the stationary objects and a gyro data to solve an optimization algorithm to calculate vehicle odometry. Experimentation has been performed with a non-road vehicle driven on a straight path and on a circular path. We report our findings and show efficacy of the algorithm in comparison to the state of art [8] as well as wheel odometry and a complete navigation solution (including GNSS) as the reference path.
AB - In this paper, we propose an algorithm for complete odometry of a vehicle on a horizontal plane., that is., estimation of linear velocity vector (forward and sideslip speeds) and angular speed of a vehicle. The vehicle is equipped with an automotive Radar sensor and a vertical gyro. The Radar sensor provides radial speed and azimuth angle of number of objects in the environment. We first derive the kinematic constraints imposed on the vehicle motion and stationary points in the environment. Using the constraints we classify the points detected by the Radar to stationary and non-stationary points. It is known that using data from a single Radar., the abovementioned constraints are singular. Previous works have thus proposed the use of more than one Radar sensor., or they have neglected the sideslip speed. In our work, we then use the Radar data of the stationary objects and a gyro data to solve an optimization algorithm to calculate vehicle odometry. Experimentation has been performed with a non-road vehicle driven on a straight path and on a circular path. We report our findings and show efficacy of the algorithm in comparison to the state of art [8] as well as wheel odometry and a complete navigation solution (including GNSS) as the reference path.
U2 - 10.1109/MED.2018.8442474
DO - 10.1109/MED.2018.8442474
M3 - Conference contribution
SN - 9781538678909
SP - 855
EP - 860
BT - MED 2018 - 26th Mediterranean Conference on Control and Automation
PB - IEEE
ER -
TY - GEN
T1 - Composite nonlinear feedback control of a JIB trolley of a tower cranebehaviors
AU - Pyrhönen, Veli-Pekka
AU - Vilkko, Matti K.
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Cranes are required to lift and carry loads swiftly to desired positions without causing excessive swaying motion of the load. These are conflicting requirements, which make feedback control of crane systems challenging. Furthermore, variations in rope length and load mass complicate controller design, since they significantly influence swaying dynamics. This paper considers automatic control of Quanser 3DOF tower crane system using composite nonlinear feedback (CNF) methodology. To be more specific, a CNF controller is designed for the jib trolley position of the crane using partial state measurements. The performance of the CNF controller is compared with Quanser's built-in linear quadratic regulator (LQR) controller both in simulation and experimental setups. The results show that the CNF controller provides better load handling capability in terms of fast positioning of the jib trolley and damping of load swaying.
AB - Cranes are required to lift and carry loads swiftly to desired positions without causing excessive swaying motion of the load. These are conflicting requirements, which make feedback control of crane systems challenging. Furthermore, variations in rope length and load mass complicate controller design, since they significantly influence swaying dynamics. This paper considers automatic control of Quanser 3DOF tower crane system using composite nonlinear feedback (CNF) methodology. To be more specific, a CNF controller is designed for the jib trolley position of the crane using partial state measurements. The performance of the CNF controller is compared with Quanser's built-in linear quadratic regulator (LQR) controller both in simulation and experimental setups. The results show that the CNF controller provides better load handling capability in terms of fast positioning of the jib trolley and damping of load swaying.
U2 - 10.23919/ECC.2019.8796229
DO - 10.23919/ECC.2019.8796229
M3 - Conference contribution
SP - 1124
EP - 1129
BT - 2019 18th European Control Conference, ECC 2019
PB - IEEE
ER -
TY - GEN
T1 - Computationally efficient optimization algorithms for model predictive control of linear systems with integer inputs
AU - Karamanakos, Petros
AU - Geyer, Tobias
AU - Kennel, Ralph
PY - 2015/12/16
Y1 - 2015/12/16
N2 - The model predictive control problem of linear systems with integer inputs results in an integer optimization problem. In case of a quadratic objective function, the optimization problem can be cast as an integer least-squares (ILS) problem. Three algorithms to solve this problem are proposed in this paper. Optimality can be traded in to reduce the computation time. An industrial case study-an inverter-driven electrical drive system-is considered to demonstrate the effectiveness of the presented techniques.
AB - The model predictive control problem of linear systems with integer inputs results in an integer optimization problem. In case of a quadratic objective function, the optimization problem can be cast as an integer least-squares (ILS) problem. Three algorithms to solve this problem are proposed in this paper. Optimality can be traded in to reduce the computation time. An industrial case study-an inverter-driven electrical drive system-is considered to demonstrate the effectiveness of the presented techniques.
U2 - 10.1109/CDC.2015.7402787
DO - 10.1109/CDC.2015.7402787
M3 - Conference contribution
SP - 3663
EP - 3668
BT - 2015 54th IEEE Conference on Decision and Control, CDC 2015
ER -
TY - GEN
T1 - Constrained Long-Horizon Direct Model Predictive Control for Synchronous Reluctance Motor Drives
AU - Ortombina, L.
AU - Liegmann, E.
AU - Karamanakos, P.
AU - Tinazzi, F.
AU - Zigliotto, M.
AU - Kennel, R.
N1 - JUFOID=79370
PY - 2018/9/10
Y1 - 2018/9/10
N2 - A finite control set model predictive control strategy for the control of the stator currents of a synchronous reluctance motor driven by a three-level neutral point clamped inverter is presented in this paper. The presented algorithm minimizes the stator current distortions while operating the drive system at switching frequencies of a few hundred Hertz. Moreover, the power electronic converter is protected by overcurrents and/or overvoltages owing to a hard constraint imposed on the stator currents. To efficiently solve the underlying integer nonlinear optimization problem a sphere decoding algorithm serves as optimizer. To this end, a numerical calculation of the unconstrained solution of the optimization problem is proposed, along with modifications in the algorithm proposed in [1] so as to meet the above-mentioned control objectives. Simulation results show the effectiveness of the proposed control algorithm.
AB - A finite control set model predictive control strategy for the control of the stator currents of a synchronous reluctance motor driven by a three-level neutral point clamped inverter is presented in this paper. The presented algorithm minimizes the stator current distortions while operating the drive system at switching frequencies of a few hundred Hertz. Moreover, the power electronic converter is protected by overcurrents and/or overvoltages owing to a hard constraint imposed on the stator currents. To efficiently solve the underlying integer nonlinear optimization problem a sphere decoding algorithm serves as optimizer. To this end, a numerical calculation of the unconstrained solution of the optimization problem is proposed, along with modifications in the algorithm proposed in [1] so as to meet the above-mentioned control objectives. Simulation results show the effectiveness of the proposed control algorithm.
U2 - 10.1109/COMPEL.2018.8460173
DO - 10.1109/COMPEL.2018.8460173
M3 - Conference contribution
SN - 9781538655412
BT - 2018 IEEE 19th Workshop on Control and Modeling for Power Electronics, COMPEL 2018
PB - IEEE
ER -
TY - GEN
T1 - Determining maximum MPP-tracking sampling frequency for input-voltage-controlled PV-interfacing converter
AU - Kivimäki, Jyri
AU - Sitbon, Moshe
AU - Kolesnik, Sergei
AU - Kuperman, Alon
AU - Suntio, Teuvo
PY - 2017/2/13
Y1 - 2017/2/13
N2 - A maximum-power-point tracking (MPPT) algorithm is essential in all controllers of solar power electronic converters due to the nonlinear current-voltage characteristics of a photovoltaic generator. One of the most widely utilized algorithms are perturbative MPPT techniques such as perturb and observe and incremental conductance methods due to their simple implementation with relatively good tracking performance. However, in order to optimize the performance of such algorithms, the design parameters - sampling frequency and perturbation step size - need to be designed in respect to interfaced power electronic converter. Recent studies have provided state-of-art MPP-tracking design rules for single and two-stage grid-connected PV systems. Unfortunately, the analysis of those studies does not provide analytical results for PV power transient response under feedback-controlled converters. This paper provides reduced-order transfer functions for the converters equipped with either I-type or PID-type controllers in order to approximate the maximum sampling or perturbation frequency for MPP-tracking algorithms. The analysis reveals the factors affecting the transient behavior similarly as in open-loop converter providing valuable tools for optimizing MPP-tracking perturbation frequency design.
AB - A maximum-power-point tracking (MPPT) algorithm is essential in all controllers of solar power electronic converters due to the nonlinear current-voltage characteristics of a photovoltaic generator. One of the most widely utilized algorithms are perturbative MPPT techniques such as perturb and observe and incremental conductance methods due to their simple implementation with relatively good tracking performance. However, in order to optimize the performance of such algorithms, the design parameters - sampling frequency and perturbation step size - need to be designed in respect to interfaced power electronic converter. Recent studies have provided state-of-art MPP-tracking design rules for single and two-stage grid-connected PV systems. Unfortunately, the analysis of those studies does not provide analytical results for PV power transient response under feedback-controlled converters. This paper provides reduced-order transfer functions for the converters equipped with either I-type or PID-type controllers in order to approximate the maximum sampling or perturbation frequency for MPP-tracking algorithms. The analysis reveals the factors affecting the transient behavior similarly as in open-loop converter providing valuable tools for optimizing MPP-tracking perturbation frequency design.
U2 - 10.1109/ECCE.2016.7855036
DO - 10.1109/ECCE.2016.7855036
M3 - Conference contribution
BT - 8th Annual IEEE Energy Conversion Congress & Exposition (ECCE 2016)
PB - IEEE
ER -
TY - GEN
T1 - Direct model predictive power control of a series-connected modular rectifier
AU - Rossi, Mattia
AU - Liegmann, Eyke
AU - Karamanakos, Petros
AU - Castelli-Dezza, Francesco
AU - Kennel, Ralph
PY - 2019/5/1
Y1 - 2019/5/1
N2 - This paper presents a direct model predictive power control for a series-connected modular rectifier. The topology combines a diode rectifier and an active-front-end (AFE) converter to achieve a medium voltage target. A voltage control loop regulates the total dc voltage, providing the power references to the inner direct model predictive control. Operation under the desired real and reactive power is achieved, while minimizing the converter switching frequency. Moreover, successful operation and control of the AFE converter is guaranteed thanks to a hard constraint included in the optimization problem.
AB - This paper presents a direct model predictive power control for a series-connected modular rectifier. The topology combines a diode rectifier and an active-front-end (AFE) converter to achieve a medium voltage target. A voltage control loop regulates the total dc voltage, providing the power references to the inner direct model predictive control. Operation under the desired real and reactive power is achieved, while minimizing the converter switching frequency. Moreover, successful operation and control of the AFE converter is guaranteed thanks to a hard constraint included in the optimization problem.
U2 - 10.1109/PRECEDE.2019.8753318
DO - 10.1109/PRECEDE.2019.8753318
M3 - Conference contribution
SP - 1
EP - 6
BT - PRECEDE 2019
PB - IEEE
ER -
TY - GEN
T1 - Dual-frequency signal processing architecture for robust and precise positioning applications
AU - Bolla, Padma
AU - Lohan, Elena-Simona
N1 - EXT="Bolla, Padma"
jufoid=72638
PY - 2018/6/5
Y1 - 2018/6/5
N2 - Availability of new GPS civil signals L2C and L5 along with existed L1C/A signal and Galileo E1/E5/E6 signals has increased the potential ways to generate linear combination of signals to remove ionosphere errors and improve accuracy in carrier integer ambiguity resolution. Conventionally, a linear combination of dual frequency signals has been used to remove first order ionosphere delays incurred in signal propagation path which is a major source of range error. Out of the three civil signals in GPS and Galileo system, L5/E5 signals have advanced signal features such as higher received power, faster chip rate and lower carrier frequency than L1/E1 and L2C/E6 signals. Hence, dual frequency receiver with combination of L1/L5 and E1/E5 signals is more suitable to remove ionosphere delay and get benefit from L5/E5 signal characteristics. However, the major limitation of linear combination of signal observations is an amplification of receiver noise. To get benefit of two frequency signals, a suitable signal processing architecture is needed. By taking advantage of GPS L5/Galileo E5 signal characteristics, a dual frequency signal processing architecture is proposed with an aim to reduce the ionosphere-free signal observation noise and to enhance the L1/E1 signal tracking loop sensitivity. The L1/E1 signal tracking loop sensitivity can be enhanced by Doppler aiding from L5/E5 signal tracking loop. The low noise L5/E5 signal Doppler aid reduces the noise in the L1/E1 signal tracking loop. Moreover, two frequency signals tracked with common Doppler estimate will have common observation errors, which will get cancel in linear combination of observations i.e. ionosphere-free, wide-lane etc. Further, code phase observations can be smoothed (Hatch filter) using carrier phase observations. The carrier phase observations are limited by cycle slip. Hence, we have investigated an optimum combination of divergence-free and ionosphere-free pseudorange smoothing using dual-frequency carrier Doppler observations for GPS L1/L5 and Galileo E1/E5 signals. The cycle slip in carrier phase observations can be neglected in carrier Doppler observations. The proposed signal processing architecture incorporated in GPS L1/L5 and Galileo E1/E5 dual frequency receiver will ensure robust signal tracking and minimum pseudorange errors, suitable to a range of high accuracy standalone and code differential positioning applications. The performance of the proposed dual frequency signal processing architecture is evaluated with GPS L1/L5 signals collected from Block-IIF satellites.
AB - Availability of new GPS civil signals L2C and L5 along with existed L1C/A signal and Galileo E1/E5/E6 signals has increased the potential ways to generate linear combination of signals to remove ionosphere errors and improve accuracy in carrier integer ambiguity resolution. Conventionally, a linear combination of dual frequency signals has been used to remove first order ionosphere delays incurred in signal propagation path which is a major source of range error. Out of the three civil signals in GPS and Galileo system, L5/E5 signals have advanced signal features such as higher received power, faster chip rate and lower carrier frequency than L1/E1 and L2C/E6 signals. Hence, dual frequency receiver with combination of L1/L5 and E1/E5 signals is more suitable to remove ionosphere delay and get benefit from L5/E5 signal characteristics. However, the major limitation of linear combination of signal observations is an amplification of receiver noise. To get benefit of two frequency signals, a suitable signal processing architecture is needed. By taking advantage of GPS L5/Galileo E5 signal characteristics, a dual frequency signal processing architecture is proposed with an aim to reduce the ionosphere-free signal observation noise and to enhance the L1/E1 signal tracking loop sensitivity. The L1/E1 signal tracking loop sensitivity can be enhanced by Doppler aiding from L5/E5 signal tracking loop. The low noise L5/E5 signal Doppler aid reduces the noise in the L1/E1 signal tracking loop. Moreover, two frequency signals tracked with common Doppler estimate will have common observation errors, which will get cancel in linear combination of observations i.e. ionosphere-free, wide-lane etc. Further, code phase observations can be smoothed (Hatch filter) using carrier phase observations. The carrier phase observations are limited by cycle slip. Hence, we have investigated an optimum combination of divergence-free and ionosphere-free pseudorange smoothing using dual-frequency carrier Doppler observations for GPS L1/L5 and Galileo E1/E5 signals. The cycle slip in carrier phase observations can be neglected in carrier Doppler observations. The proposed signal processing architecture incorporated in GPS L1/L5 and Galileo E1/E5 dual frequency receiver will ensure robust signal tracking and minimum pseudorange errors, suitable to a range of high accuracy standalone and code differential positioning applications. The performance of the proposed dual frequency signal processing architecture is evaluated with GPS L1/L5 signals collected from Block-IIF satellites.
KW - Carrier Doppler smoothing
KW - Doppler aiding
KW - Dual-frequency
KW - Hatch filter
U2 - 10.1109/PLANS.2018.8373367
DO - 10.1109/PLANS.2018.8373367
M3 - Conference contribution
SP - 72
EP - 80
BT - 2018 IEEE/ION Position, Location and Navigation Symposium, PLANS 2018
PB - IEEE
ER -
TY - GEN
T1 - Fabrication of soft devices with buried fluid channels by using sacrificial 3D printed molds
AU - Koivikko, Anastasia
AU - Sariola, Veikko
PY - 2019/5/24
Y1 - 2019/5/24
N2 - Casting silicone elastomers into 3D printed molds has seen a surge of applications in soft robots, soft manipulators, microfluidics, wearable technologies and stretchable sensors. In such devices, buried fluid channels are used to transport fluids, as fluidic actuators and as sensors with liquid metal. However, it is difficult to demold structures with buried channels or overhangs. As a solution, using sacrificial molds made of dissolvable materials has been proposed. In this paper, we evaluate different commercially available 3D printing materials as dissolvable mold materials. We tested dissolving prints made of high-impact polystyrene (HIPS), acrylonitrile butadiene styrene (ABS), polyvinyl butyral (PVB) and polyvinyl alcohol (PVA) in limonene, acetone, isopropanol/ethanol and water, respectively. We further studied the effect of magnetic stirring and ultrasonic bath on the dissolution times. Finally, we fabricated buried channels using different mold materials and silicone elastomers. The results show that at least ABS, PVB and PVA can be used as mold materials. In particular, PVA is a promising material as it is soluble in water. The studied method simplifies the fabrication of soft devices, allowing the fabrication of overhangs and buried channels in a single casting step.
AB - Casting silicone elastomers into 3D printed molds has seen a surge of applications in soft robots, soft manipulators, microfluidics, wearable technologies and stretchable sensors. In such devices, buried fluid channels are used to transport fluids, as fluidic actuators and as sensors with liquid metal. However, it is difficult to demold structures with buried channels or overhangs. As a solution, using sacrificial molds made of dissolvable materials has been proposed. In this paper, we evaluate different commercially available 3D printing materials as dissolvable mold materials. We tested dissolving prints made of high-impact polystyrene (HIPS), acrylonitrile butadiene styrene (ABS), polyvinyl butyral (PVB) and polyvinyl alcohol (PVA) in limonene, acetone, isopropanol/ethanol and water, respectively. We further studied the effect of magnetic stirring and ultrasonic bath on the dissolution times. Finally, we fabricated buried channels using different mold materials and silicone elastomers. The results show that at least ABS, PVB and PVA can be used as mold materials. In particular, PVA is a promising material as it is soluble in water. The studied method simplifies the fabrication of soft devices, allowing the fabrication of overhangs and buried channels in a single casting step.
U2 - 10.1109/ROBOSOFT.2019.8722741
DO - 10.1109/ROBOSOFT.2019.8722741
M3 - Conference contribution
SP - 509
EP - 513
BT - 2019 2nd IEEE International Conference on Soft Robotics (RoboSoft)
PB - IEEE
ER -
TY - GEN
T1 - Improved modelling of electric loads for enabling demand response by applying physical and data-driven models
T2 - Project Response
AU - Koponen, Pekka
AU - Hanninen, Seppo
AU - Mutanen, Antti
AU - Koskela, Juha
AU - Rautiainen, Antti
AU - Järventausta, Pertti
AU - Niska, Harri
AU - Kolehmainen, Mikko
AU - Koivisto, Hannu
PY - 2018/6/27
Y1 - 2018/6/27
N2 - Accurate load and response forecasts are a critical enabler for high demand response penetrations and optimization of responses and market actions. Project RESPONSE studies and develops methods to improve the forecasts. Its objectives are to improve 1) load and response forecast and optimization models based on both data-driven and physical modelling, and their hybrid models, 2) utilization of various data sources such as smart metering data, weather data, measurements from substations etc., and 3) performance criteria of load forecasting. The project applies, develops, compares, and integrates various modelling approaches including partly physical models, machine learning, modern load profiling, autoregressive models, and Kalman-filtering. It also applies non-linear constrained optimization to load responses. This paper gives an overview of the project and the results achieved so far.
AB - Accurate load and response forecasts are a critical enabler for high demand response penetrations and optimization of responses and market actions. Project RESPONSE studies and develops methods to improve the forecasts. Its objectives are to improve 1) load and response forecast and optimization models based on both data-driven and physical modelling, and their hybrid models, 2) utilization of various data sources such as smart metering data, weather data, measurements from substations etc., and 3) performance criteria of load forecasting. The project applies, develops, compares, and integrates various modelling approaches including partly physical models, machine learning, modern load profiling, autoregressive models, and Kalman-filtering. It also applies non-linear constrained optimization to load responses. This paper gives an overview of the project and the results achieved so far.
KW - Active demand
KW - Forecasting
KW - Hybrid models
KW - Machine learning
KW - Optimization
KW - Physically based models
U2 - 10.1109/ENERGYCON.2018.8398794
DO - 10.1109/ENERGYCON.2018.8398794
M3 - Conference contribution
SP - 1
EP - 6
BT - 2018 IEEE International Energy Conference, ENERGYCON 2018
PB - IEEE
ER -
TY - GEN
T1 - Improvement of GPS and BeiDou extended orbit predictions with CNNs
AU - Pihlajasalo, Jaakko
AU - Leppäkoski, Helena
AU - Ali-Löytty, Simo
AU - Piché, Robert
N1 - INT=mat,"Jaakko Pihlajasalo"
PY - 2018/8/10
Y1 - 2018/8/10
N2 - This paper presents a method for improving the accuracy of extended GNSS satellite orbit predictions with convolutional neural networks (CNN). Satellite orbit predictions are used in self-assisted GNSS to reduce the Time to First Fix of a satellite positioning device. We describe the models we use to predict the satellite orbit and present the improvement method that uses CNN. The CNN estimates future prediction errors of our model and these estimates are used to correct our orbit predictions. We also describe how the neural network can be implemented into our prediction algorithm. In tests with GPS and BeiDou data, the method significantly improves orbit prediction accuracy. For example, the 68% error quantile of 7 day orbit prediction errors of GPS satellites was reduced by 45% on average.
AB - This paper presents a method for improving the accuracy of extended GNSS satellite orbit predictions with convolutional neural networks (CNN). Satellite orbit predictions are used in self-assisted GNSS to reduce the Time to First Fix of a satellite positioning device. We describe the models we use to predict the satellite orbit and present the improvement method that uses CNN. The CNN estimates future prediction errors of our model and these estimates are used to correct our orbit predictions. We also describe how the neural network can be implemented into our prediction algorithm. In tests with GPS and BeiDou data, the method significantly improves orbit prediction accuracy. For example, the 68% error quantile of 7 day orbit prediction errors of GPS satellites was reduced by 45% on average.
U2 - 10.1109/EURONAV.2018.8433244
DO - 10.1109/EURONAV.2018.8433244
M3 - Conference contribution
SN - 9781538649626
SP - 54
EP - 59
BT - 26th European Navigation Conference, ENC 2018
PB - IEEE
ER -
TY - GEN
T1 - Inertial Sensor-Based State Estimation of Flexible Links Subject to Bending and Torsion
AU - Mäkinen, Petri
AU - Mononen, Teemu
AU - Mattila, Jouni
PY - 2018/8/27
Y1 - 2018/8/27
N2 - In this study, we propose an observer design based on inertial sensors and the finite element (FE) method to estimate the flexural states of a long-reach and highly flexible manipulator in a 3D plane of motion. Vertical and lateral dynamic bendings are considered, along with deformation due to torsion. The aim is to achieve accurate end-point positioning by using the estimated flexural degrees-of-freedom, which are formulated using an FE model. The states are reconstructed based on angular velocity measurements, which are obtained from strap-on inertial sensors placed along the flexible link. For validation, a motion-capture setup consisting of three OptiTrack cameras is used. The experiments are conducted on a hydraulic manipulator that has a single 4.5-m long flexible link with a tip mass. The validation is carried out by comparing the estimates to the OptiTrack reference measurements. The results demonstrate that this method provides satisfactory end-point positioning, while also being convenient for use in heavy-duty mobile manipulators.
AB - In this study, we propose an observer design based on inertial sensors and the finite element (FE) method to estimate the flexural states of a long-reach and highly flexible manipulator in a 3D plane of motion. Vertical and lateral dynamic bendings are considered, along with deformation due to torsion. The aim is to achieve accurate end-point positioning by using the estimated flexural degrees-of-freedom, which are formulated using an FE model. The states are reconstructed based on angular velocity measurements, which are obtained from strap-on inertial sensors placed along the flexible link. For validation, a motion-capture setup consisting of three OptiTrack cameras is used. The experiments are conducted on a hydraulic manipulator that has a single 4.5-m long flexible link with a tip mass. The validation is carried out by comparing the estimates to the OptiTrack reference measurements. The results demonstrate that this method provides satisfactory end-point positioning, while also being convenient for use in heavy-duty mobile manipulators.
KW - finite element method
KW - inertial sensors
KW - state estimation
U2 - 10.1109/MESA.2018.8449188
DO - 10.1109/MESA.2018.8449188
M3 - Conference contribution
SN - 9781538646434
BT - 2018 14th IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, MESA 2018
PB - IEEE
ER -
TY - GEN
T1 - Kalman-Type Filters and Smoothers for Pedestrian Dead Reckoning
AU - Ivanov, Pavel
AU - Raitoharju, Matti
AU - Piché, Robert
N1 - jufoid=72210
PY - 2018/11/13
Y1 - 2018/11/13
N2 - In this paper, we present a method for device localization based on the fusion of location data from Global Navigation Satellite System and data from inertial sensors. We use a Kalman filter as well as its non-linear variants for realtime position estimation, and corresponding smoothers for offline position estimation. In all filters we use information about changes of user's heading, which are computed from the acceleration and gyroscope data. Models used with Extended and Unscented Kalman filters also take into account information about step length, whereas Kalman Filter does not, because the measurement is non-linear. In order to overcome this shortcoming, we introduce a modified Kalman Filter which adjusts the state vector according to the step length measurements. Our experiments show that use of step length information does not significantly improve performance when location measurements are constantly available. However, in real situations, when location data is partially unavailable, information about step length and its appropriate integration into the filter design is important, and improve localization accuracy considerably.
AB - In this paper, we present a method for device localization based on the fusion of location data from Global Navigation Satellite System and data from inertial sensors. We use a Kalman filter as well as its non-linear variants for realtime position estimation, and corresponding smoothers for offline position estimation. In all filters we use information about changes of user's heading, which are computed from the acceleration and gyroscope data. Models used with Extended and Unscented Kalman filters also take into account information about step length, whereas Kalman Filter does not, because the measurement is non-linear. In order to overcome this shortcoming, we introduce a modified Kalman Filter which adjusts the state vector according to the step length measurements. Our experiments show that use of step length information does not significantly improve performance when location measurements are constantly available. However, in real situations, when location data is partially unavailable, information about step length and its appropriate integration into the filter design is important, and improve localization accuracy considerably.
U2 - 10.1109/IPIN.2018.8533753
DO - 10.1109/IPIN.2018.8533753
M3 - Conference contribution
BT - IPIN 2018 - 9th International Conference on Indoor Positioning and Indoor Navigation
PB - IEEE
ER -
TY - GEN
T1 - Locomotion of light-driven soft microrobots through a hydrogel via local melting
AU - Palagi, Stefano
AU - Mark, Andrew G.
AU - Melde, Kai
AU - Qiu, Tian
AU - Zeng, Hao
AU - Parmeggiani, Camilla
AU - Martella, Daniele
AU - Wiersma, Diederik S.
AU - Fischer, Peer
PY - 2017/8/3
Y1 - 2017/8/3
N2 - Soft mobile microrobots whose deformation can be directly controlled by an external field can adapt to move in different environments. This is the case for the light-driven microrobots based on liquid-crystal elastomers (LCEs). Here we show that the soft microrobots can move through an agarose hydrogel by means of light-controlled travelling-wave motions. This is achieved by exploiting the inherent rise of the LCE temperature above the melting temperature of the agarose gel, which facilitates penetration of the microrobot through the hydrogel. The locomotion performance is investigated as a function of the travelling-wave parameters, showing that effective propulsion can be obtained by adapting the generated motion to the specific environmental conditions.
AB - Soft mobile microrobots whose deformation can be directly controlled by an external field can adapt to move in different environments. This is the case for the light-driven microrobots based on liquid-crystal elastomers (LCEs). Here we show that the soft microrobots can move through an agarose hydrogel by means of light-controlled travelling-wave motions. This is achieved by exploiting the inherent rise of the LCE temperature above the melting temperature of the agarose gel, which facilitates penetration of the microrobot through the hydrogel. The locomotion performance is investigated as a function of the travelling-wave parameters, showing that effective propulsion can be obtained by adapting the generated motion to the specific environmental conditions.
KW - Hydrogels
KW - Liquid-crystal elastomers (LCEs)
KW - Soft microrobots
U2 - 10.1109/MARSS.2017.8001916
DO - 10.1109/MARSS.2017.8001916
M3 - Conference contribution
BT - International Conference on Manipulation, Automation and Robotics at Small Scales, MARSS 2017 - Proceedings
PB - IEEE
ER -
TY - GEN
T1 - Maximum achievable throughput and interference mitigation for SUN in coexistence with WLAN
AU - Mohamed, Saad
AU - Hamila, Ridha
AU - Al-Dhahir, Naofal
AU - Gouissem, Ala
AU - Benbrahim, Lazhar
AU - Gabbouj, Moncef
N1 - EXT="Hamila, Ridha"
PY - 2018/5/16
Y1 - 2018/5/16
N2 - An optimum packet length selection scheme to maximize the throughput of a smart utility network (SUN) is introduced under wireless local area network (WLAN) interference system. The traditional and the investigated segmented packet collision models (PCM) are compared in terms of packet error rate (PER) and maximum achievable throughput. Furthermore, we quantify the impact of minimum mean square error (MMSE) interference mitigation for the SUN in the coexistence of WLAN interfering packets over multipath Rayleigh fading channel. The effect of the distance between the WLAN transmitter and the SUN receiver on the probability of error is also investigated.
AB - An optimum packet length selection scheme to maximize the throughput of a smart utility network (SUN) is introduced under wireless local area network (WLAN) interference system. The traditional and the investigated segmented packet collision models (PCM) are compared in terms of packet error rate (PER) and maximum achievable throughput. Furthermore, we quantify the impact of minimum mean square error (MMSE) interference mitigation for the SUN in the coexistence of WLAN interfering packets over multipath Rayleigh fading channel. The effect of the distance between the WLAN transmitter and the SUN receiver on the probability of error is also investigated.
KW - Interference mitigation
KW - Minimum mean square error
KW - Packet collision model
KW - Packet length
KW - Smart grid
KW - Smart utility network
KW - Throughput
U2 - 10.1109/COMMNET.2018.8360252
DO - 10.1109/COMMNET.2018.8360252
M3 - Conference contribution
SP - 1
EP - 6
BT - Proceedings - 2018 International Conference on Advanced Communication Technologies and Networking, CommNet 2018
PB - IEEE
ER -
TY - GEN
T1 - Monitoring of production processes and the condition of the production equipment through the internet
AU - Halme, Jari
AU - Jantunen, Erkki
AU - Hastbacka, David
AU - Hegedus, Csaba
AU - Varga, Pal
AU - Bjorkbom, Mikael
AU - Mesia, Heikki
AU - More, Rupesh
AU - Jaatinen, Antti
AU - Barna, Laurentiu
AU - Tuominen, Pasi
AU - Pettinen, Henri
AU - Elo, Marko
AU - Larranaga, Martin
N1 - EXT="Barna, Laurentiu"
PY - 2019/4/1
Y1 - 2019/4/1
N2 - The decreasing prices of monitoring equipment have vastly increased the opportunities to utilize local data, and data processing for wider global web-based monitoring purposes. The possible amount of data flowing though different levels can be huge. Now the question is how to handle this opportunity in both dynamic and secure way. The paper presents a new concept to manage data for monitoring through the Internet. The concept is based on the use of Arrowhead Framework (AF) and MIMOSA data model, and selected edge, and gateway devices together with cloud computing opportunities. The concept enables the flexible and secure orchestration of run-time data sources and the utilization of computational services for various process and condition monitoring needs.
AB - The decreasing prices of monitoring equipment have vastly increased the opportunities to utilize local data, and data processing for wider global web-based monitoring purposes. The possible amount of data flowing though different levels can be huge. Now the question is how to handle this opportunity in both dynamic and secure way. The paper presents a new concept to manage data for monitoring through the Internet. The concept is based on the use of Arrowhead Framework (AF) and MIMOSA data model, and selected edge, and gateway devices together with cloud computing opportunities. The concept enables the flexible and secure orchestration of run-time data sources and the utilization of computational services for various process and condition monitoring needs.
U2 - 10.1109/CoDIT.2019.8820688
DO - 10.1109/CoDIT.2019.8820688
M3 - Conference contribution
SP - 1295
EP - 1300
BT - 2019 6th International Conference on Control, Decision and Information Technologies, CoDIT 2019
PB - IEEE
ER -
TY - GEN
T1 - Online learning in neural decoding using incremental linear discriminant analysis
AU - Lee, Yaesop
AU - Madayambath, Sreenuj Chellath
AU - Liu, Yanzhou
AU - Lin, Da Ting
AU - Chen, Rong
AU - Bhattacharyya, Shuvra S.
PY - 2018/1/19
Y1 - 2018/1/19
N2 - Neural decoding focuses on predicting behavior variables based on neural activities. Linear discriminant analysis (LDA) has been successfully used in pattern recognition and machine learning to find the set of discriminant vectors to characterize two or more classes of objects. However, LDA cannot be directly used for real-time neural decoding problems. In this paper, we propose an incremental LDA with online learning method to overcome this limitation. The dataflow techniques are implemented in the LIDE (LIghtweight Dataflow Environment), which provides capabilities to systematically optimize and integrate embedded software components for signal and information processing. Using these techniques along with online learning, an efficient real-time neural decoding system can be attained.
AB - Neural decoding focuses on predicting behavior variables based on neural activities. Linear discriminant analysis (LDA) has been successfully used in pattern recognition and machine learning to find the set of discriminant vectors to characterize two or more classes of objects. However, LDA cannot be directly used for real-time neural decoding problems. In this paper, we propose an incremental LDA with online learning method to overcome this limitation. The dataflow techniques are implemented in the LIDE (LIghtweight Dataflow Environment), which provides capabilities to systematically optimize and integrate embedded software components for signal and information processing. Using these techniques along with online learning, an efficient real-time neural decoding system can be attained.
KW - dataflow
KW - ILDA
KW - incremental learning
KW - Neural decoding
KW - online learning
U2 - 10.1109/CBS.2017.8266092
DO - 10.1109/CBS.2017.8266092
M3 - Conference contribution
SP - 173
EP - 177
BT - 2017 IEEE International Conference on Cyborg and Bionic Systems, CBS 2017
PB - IEEE
ER -
TY - GEN
T1 - On Robust Output Regulation for Continuous-Time Periodic Systems
AU - Paunonen, Lassi
PY - 2015
Y1 - 2015
N2 - We construct a controller to solve robust output tracking problem for a stable linear continuous-time periodic system on a finite-dimensional space. We begin by transforming the time-dependent plant to a time-invariant discrete-time system using the ``lifting technique''. The controller is then designed to achieve robust output tracking for the lifted system. We show that an exact solution to the control problem for a continuous-time periodic system necessarily requires an error feedback controller with an infinite-dimensional internal model. The results are illustrated with an example where robust output tracking is considered for a stable periodic scalar system.
AB - We construct a controller to solve robust output tracking problem for a stable linear continuous-time periodic system on a finite-dimensional space. We begin by transforming the time-dependent plant to a time-invariant discrete-time system using the ``lifting technique''. The controller is then designed to achieve robust output tracking for the lifted system. We show that an exact solution to the control problem for a continuous-time periodic system necessarily requires an error feedback controller with an infinite-dimensional internal model. The results are illustrated with an example where robust output tracking is considered for a stable periodic scalar system.
U2 - 10.1137/1.9781611974072.7
DO - 10.1137/1.9781611974072.7
M3 - Conference contribution
BT - 2015 Proceedings of the SIAM Conference on Control and its Applications
PB - SIAM, Society for Industrial and Applied Mathematics
ER -
TY - GEN
T1 - Operating point dependent variable switching point predictive current control for PMSM drives
AU - Wendel, Sebastian
AU - Karamanakos, Petros
AU - Dietz, Armin
AU - Kennel, Ralph
PY - 2019/5/1
Y1 - 2019/5/1
N2 - This contribution presents a direct model predictive current control approach that achieves favorable performance during transients while minimizing the torque and current ripples at steady-state operation by increasing the granularity at which switching can be performed. To meet the control goals, an optimization problem is solved in real-time that decides whether only one discrete voltage space vector or a combination of two is selected. In the latter case, a variable switching point, i.e., a time instant within the control interval at which the converter switches change state, is computed. The proposed method is advantageous, e.g., for electric drives in machine tools, in which, depending on the operating point, fast dynamics and a low torque ripple are important. The approach is evaluated at the example of a two-level voltage source inverter driving a permanent magnet synchronous machine.
AB - This contribution presents a direct model predictive current control approach that achieves favorable performance during transients while minimizing the torque and current ripples at steady-state operation by increasing the granularity at which switching can be performed. To meet the control goals, an optimization problem is solved in real-time that decides whether only one discrete voltage space vector or a combination of two is selected. In the latter case, a variable switching point, i.e., a time instant within the control interval at which the converter switches change state, is computed. The proposed method is advantageous, e.g., for electric drives in machine tools, in which, depending on the operating point, fast dynamics and a low torque ripple are important. The approach is evaluated at the example of a two-level voltage source inverter driving a permanent magnet synchronous machine.
KW - Direct model predictive control (DMPC)
KW - Finite control set model predictive control (FCS-MPC)
KW - SoC FPGA
KW - Variable switching point predictive current control (VSP2CC)
U2 - 10.1109/PRECEDE.2019.8753362
DO - 10.1109/PRECEDE.2019.8753362
M3 - Conference contribution
SP - 1
EP - 6
BT - PRECEDE 2019
PB - IEEE
ER -
TY - GEN
T1 - Outage probability of multi-carrier NOMA systems under joint I/Q imbalance
AU - Selim, Bassant
AU - Muhaidat, Sami
AU - Sofotasios, Paschalis C.
AU - Sharif, Bayan S.
AU - Stouraitis, Thanos
AU - Karagiannidis, George K.
AU - Al-Dhahir, Naofal
PY - 2018/5/16
Y1 - 2018/5/16
N2 - Non-orthogonal multiple access (NOMA) has been recently proposed as a viable technology that can potentially improve the spectral efficiency of fifth generation (5G) wireless networks and beyond. However, in practical communication scenarios, transceiver architectures inevitably suffer from radio-frequency (RF) front-end related impairments that can lead to degradation of the overall system performance, with in-phase/quadrature-phase imbalance (IQI) constituting a major impairment in direct-conversion transceivers. In the present work, we quantify the effects of joint transmitter/receiver IQI on the performance of NOMA based multi-carrier (MC) systems under multipath fading conditions. Furthermore, we derive the asymptotic diversity order of the considered MC NOMA set up. Capitalizing on these results, we demonstrate that the effects of IQI differ considerably among NOMA users and depend on the underlying system parameters. For example, it is shown that the first sorted user appears more robust to IQI, which indicates that higher order users are more sensitive to the considered non-negligible impairment.
AB - Non-orthogonal multiple access (NOMA) has been recently proposed as a viable technology that can potentially improve the spectral efficiency of fifth generation (5G) wireless networks and beyond. However, in practical communication scenarios, transceiver architectures inevitably suffer from radio-frequency (RF) front-end related impairments that can lead to degradation of the overall system performance, with in-phase/quadrature-phase imbalance (IQI) constituting a major impairment in direct-conversion transceivers. In the present work, we quantify the effects of joint transmitter/receiver IQI on the performance of NOMA based multi-carrier (MC) systems under multipath fading conditions. Furthermore, we derive the asymptotic diversity order of the considered MC NOMA set up. Capitalizing on these results, we demonstrate that the effects of IQI differ considerably among NOMA users and depend on the underlying system parameters. For example, it is shown that the first sorted user appears more robust to IQI, which indicates that higher order users are more sensitive to the considered non-negligible impairment.
U2 - 10.1109/COMMNET.2018.8360283
DO - 10.1109/COMMNET.2018.8360283
M3 - Conference contribution
SP - 1
EP - 7
BT - Proceedings - 2018 International Conference on Advanced Communication Technologies and Networking, CommNet 2018
PB - IEEE
ER -
TY - GEN
T1 - Pneumatically actuated elastomeric device for simultaneous mechanobiological studies & live-cell fluorescent microscopy
AU - Kreutzer, Joose
AU - Viehrig, Marlitt
AU - Maki, Antti-Juhana
AU - Kallio, Pasi
AU - Rahikainen, Rolle
AU - Hytönen, Vesa
N1 - INT=tut-bmt,"Viehrig, Marlitt"
PY - 2017/8/3
Y1 - 2017/8/3
N2 - In this study, we demonstrate the functionality and usability of a compact, pneumatically actuated, elastomeric stimulation device for mechanobiological studies. The soft mechatronic device enables high-resolution live-cell confocal fluorescent imaging during equiaxial stretching. Several single cells can be tracked and imaged repeatedly after stretching periods. For demonstration, we provide image based analysis of dynamic change of the cell body and the nucleus area and actin fiber orientation during mechanical stimulation of mouse embryonic fibroblast (MEF) cells. Additionally, we present the characteristics of the device utilizing computational simulations and experimental validation using a particle tracking method for strain field analysis.
AB - In this study, we demonstrate the functionality and usability of a compact, pneumatically actuated, elastomeric stimulation device for mechanobiological studies. The soft mechatronic device enables high-resolution live-cell confocal fluorescent imaging during equiaxial stretching. Several single cells can be tracked and imaged repeatedly after stretching periods. For demonstration, we provide image based analysis of dynamic change of the cell body and the nucleus area and actin fiber orientation during mechanical stimulation of mouse embryonic fibroblast (MEF) cells. Additionally, we present the characteristics of the device utilizing computational simulations and experimental validation using a particle tracking method for strain field analysis.
KW - High-resolution imaging
KW - Mechanical stimulation
KW - Mouse embryonic fibroblasts
KW - Particle tracking
KW - PDMS
KW - Pneumatic actuation
KW - Strain field analysis
U2 - 10.1109/MARSS.2017.8001929
DO - 10.1109/MARSS.2017.8001929
M3 - Conference contribution
BT - International Conference on Manipulation, Automation and Robotics at Small Scales, MARSS 2017 - Proceedings
PB - IEEE
ER -
TY - GEN
T1 - Real-time and Robust Collaborative Robot Motion Control with Microsoft Kinect ® v2
AU - Teke, Burak
AU - Lanz, Minna
AU - Kämäräinen, Joni-Kristian
AU - Hietanen, Antti
N1 - INT=mei,"Teke, Burak"
PY - 2018/8/27
Y1 - 2018/8/27
N2 - Recent development in depth sensing provide various opportunities for the development of new methods for Human Robot Interaction (HRI). Collaborative robots (co-bots) are redefining HRI across the manufacturing industry. However, little work has been done yet in the field of HRI with Kinect sensor in this industry. In this paper, we will present a HRI study using nearest-point approach with Microsoft Kinect v2 sensor's depth image (RGB-D). The approach is based on the Euclidean distance which has robust properties against different environments. The study aims to improve the motion performance of Universal Robot-5 (UR5) and interaction efficiency during the possible collaboration using the Robot Operating System (ROS) framework and its tools. After the depth data from the Kinect sensor has been processed, the nearest points differences are transmitted to the robot via ROS.
AB - Recent development in depth sensing provide various opportunities for the development of new methods for Human Robot Interaction (HRI). Collaborative robots (co-bots) are redefining HRI across the manufacturing industry. However, little work has been done yet in the field of HRI with Kinect sensor in this industry. In this paper, we will present a HRI study using nearest-point approach with Microsoft Kinect v2 sensor's depth image (RGB-D). The approach is based on the Euclidean distance which has robust properties against different environments. The study aims to improve the motion performance of Universal Robot-5 (UR5) and interaction efficiency during the possible collaboration using the Robot Operating System (ROS) framework and its tools. After the depth data from the Kinect sensor has been processed, the nearest points differences are transmitted to the robot via ROS.
KW - collaborative robots
KW - human-robot collaboration
KW - Human-robot interaction
KW - Microsoft Kinect v2
KW - ROS
KW - trajectory planning
U2 - 10.1109/MESA.2018.8449156
DO - 10.1109/MESA.2018.8449156
M3 - Conference contribution
SN - 9781538646434
BT - 2018 14th IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, MESA 2018
PB - IEEE
ER -
TY - GEN
T1 - Robust Regulation for First-Order Port-Hamiltonian Systems
AU - Humaloja, Jukka-Pekka
AU - Paunonen, Lassi
AU - Pohjolainen, Seppo
PY - 2016
Y1 - 2016
N2 - We present a method for obtaining robust control over a first-order port-Hamiltonian system. The presented method is especially designed for controlling impedance energy-preserving port- Hamiltonian systems. By combining the stabilization results of port-Hamiltonian systems and the theory of robust output regulation for exponentially stable systems, we design a simple finite-dimensional controller for an unstable system that together with output feedback achieves robust output regulation. The method is demonstrated on an example where we implement a robust regulating controller for the one-dimensional wave equation with boundary control and observation.
AB - We present a method for obtaining robust control over a first-order port-Hamiltonian system. The presented method is especially designed for controlling impedance energy-preserving port- Hamiltonian systems. By combining the stabilization results of port-Hamiltonian systems and the theory of robust output regulation for exponentially stable systems, we design a simple finite-dimensional controller for an unstable system that together with output feedback achieves robust output regulation. The method is demonstrated on an example where we implement a robust regulating controller for the one-dimensional wave equation with boundary control and observation.
KW - Robust output regulation
KW - port-Hamiltonian systems
U2 - 10.1109/ECC.2016.7810618
DO - 10.1109/ECC.2016.7810618
M3 - Conference contribution
BT - Proceedings of the 15th European Control Conference, Aalborg, Denmark, June 29th - July 1st, 2016
PB - IEEE
ER -
TY - GEN
T1 - Robust Regulation for Port-Hamiltonian Systems of Even Order
AU - Humaloja, Jukka-Pekka
AU - Paunonen, Lassi
AU - Pohjolainen, Seppo
PY - 2016
Y1 - 2016
N2 - We present a controller that achieves robust regulation for a port-Hamiltonian system of even order. The controller is especially designed for impedance energy-preserving systems. By utilizing the stabilization results for port-Hamiltonian systems together with the theory of robust output regulation for exponentially stable systems, we construct a simple controller that solves the Robust Output Regulation Problem for an initially unstable system. The theory is illustrated on an example where we construct a controller for one- dimensional Schrödinger equation with boundary control and observation.
AB - We present a controller that achieves robust regulation for a port-Hamiltonian system of even order. The controller is especially designed for impedance energy-preserving systems. By utilizing the stabilization results for port-Hamiltonian systems together with the theory of robust output regulation for exponentially stable systems, we construct a simple controller that solves the Robust Output Regulation Problem for an initially unstable system. The theory is illustrated on an example where we construct a controller for one- dimensional Schrödinger equation with boundary control and observation.
KW - Robust output regulation
KW - port-Hamiltonian systems
M3 - Conference contribution
SP - 152
EP - 156
BT - Proceedings of the 22nd International Symposium on Mathematical Theory of Networks and Systems, Minneapolis, MN, USA, July 12-15, 2016
PB - University of Minnesota
ER -
TY - GEN
T1 - Robust Regulation of SISO Systems: The Fractional Ideal Approach
AU - Laakkonen, Petteri
AU - Quadrat, Alban
PY - 2015
Y1 - 2015
N2 - We solve the robust regulation problem for single-input single-output plants by using the fractional ideal approach and without assuming the existence of coprime factorizations. In particular, we are able to formulate the famous internal model principle for stabilizable plants which do not necessarily admit coprime factorizations. We are able to give a necessary and suffcient solvability condition for the robust regulation problem, which leads to a design method for a robustly regulating controller. The theory is illustrated by examples.
AB - We solve the robust regulation problem for single-input single-output plants by using the fractional ideal approach and without assuming the existence of coprime factorizations. In particular, we are able to formulate the famous internal model principle for stabilizable plants which do not necessarily admit coprime factorizations. We are able to give a necessary and suffcient solvability condition for the robust regulation problem, which leads to a design method for a robustly regulating controller. The theory is illustrated by examples.
U2 - 10.1137/1.9781611974072.43
DO - 10.1137/1.9781611974072.43
M3 - Conference contribution
SP - 311
EP - 318
BT - Proceedings of the SIAM Conference on Control and Its Applications (CT15)
PB - SIAM, Society for Industrial and Applied Mathematics
ER -
TY - GEN
T1 - Role-based visualization of industrial IoT-based systems
AU - Mahmoodpour, Mehdi
AU - Lobov, Andrei
AU - Lanz, Minna
AU - Mäkelä, Petteri
AU - Rundas, Niko
PY - 2018/8/27
Y1 - 2018/8/27
N2 - The competition among manufacturers in the global markets calls for the enhancement of the agility and performance of the production process and the quality of products. As a result, the production systems should be designed in such a way to provide decision makers with visibility and analytics. To fulfill these objectives, the development of information systems in manufacturing industries has intensified in the past few years. On the other hand, the volume of data which is being generated on the shop floor is rising. To improve the efficiency of manufacturing processes, this amount of data should be analyzed by decision makers. To cope with this challenge, advanced visualization is needed to assist users to gain insight into data and make effective decisions faster. This paper describes an approach for building a role-based visualization of industrial IoT. We propose an extendible architecture that anticipates the future growth of data. By using the IoT platform introduced in this paper, selected Key Performance Indicators(KPI) can be monitored by different levels of enterprise. The prototype IoT dashboard has been implemented for a pilot production line 'Festo didactic training line' located in Seinäjoki University of Applied Sciences(SeAMK) and results have been validated.
AB - The competition among manufacturers in the global markets calls for the enhancement of the agility and performance of the production process and the quality of products. As a result, the production systems should be designed in such a way to provide decision makers with visibility and analytics. To fulfill these objectives, the development of information systems in manufacturing industries has intensified in the past few years. On the other hand, the volume of data which is being generated on the shop floor is rising. To improve the efficiency of manufacturing processes, this amount of data should be analyzed by decision makers. To cope with this challenge, advanced visualization is needed to assist users to gain insight into data and make effective decisions faster. This paper describes an approach for building a role-based visualization of industrial IoT. We propose an extendible architecture that anticipates the future growth of data. By using the IoT platform introduced in this paper, selected Key Performance Indicators(KPI) can be monitored by different levels of enterprise. The prototype IoT dashboard has been implemented for a pilot production line 'Festo didactic training line' located in Seinäjoki University of Applied Sciences(SeAMK) and results have been validated.
KW - Data Collection
KW - Information Visualization
KW - Internet of Things (IoT)
U2 - 10.1109/MESA.2018.8449183
DO - 10.1109/MESA.2018.8449183
M3 - Conference contribution
SN - 9781538646434
BT - 2018 14th IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, MESA 2018
PB - IEEE
ER -
TY - GEN
T1 - Soft computing-based controller design for a telecom rectifier
AU - Gadoura, Idris
AU - Suntio, Teuvo
AU - Zenger, Kai
AU - Vallittu, Petri
PY - 1999/1/1
Y1 - 1999/1/1
N2 - Presents controller design for a telecommunications rectifier based on analogue, digital and fuzzy logic approaches. The required output characteristics contain three modes of operation-constant-voltage, modified constant-power and constant-current. The proposed analogue solution is well proven in practical use and shows excellent performance. The digital solution is simulated and preliminary results predict its applicability. The fuzzy logic solution is outlined for constant-voltage and overload controllers. Preliminary simulations are promising but further optimization must be carried out.
AB - Presents controller design for a telecommunications rectifier based on analogue, digital and fuzzy logic approaches. The required output characteristics contain three modes of operation-constant-voltage, modified constant-power and constant-current. The proposed analogue solution is well proven in practical use and shows excellent performance. The digital solution is simulated and preliminary results predict its applicability. The fuzzy logic solution is outlined for constant-voltage and overload controllers. Preliminary simulations are promising but further optimization must be carried out.
U2 - 10.1109/SMCIA.1999.782712
DO - 10.1109/SMCIA.1999.782712
M3 - Conference contribution
T3 - SMCia 1999 - Proceedings of the 1999 IEEE Midnight-Sun Workshop on Soft Computing Methods in Industrial Applications
SP - 80
EP - 85
BT - SMCia 1999 - Proceedings of the 1999 IEEE Midnight-Sun Workshop on Soft Computing Methods in Industrial Applications
A2 - Martikainen, Jarno
PB - Institute of Electrical and Electronics Engineers Inc.
ER -
TY - GEN
T1 - Sustainable electric vehicle - Prosumer framework and policy mix
AU - Kotilainen, Kirsi
AU - Mäkinen, Saku J.
AU - Valta, Jussi
N1 - EXT="Kotilainen, Kirsi"
PY - 2018/6/8
Y1 - 2018/6/8
N2 - Electric vehicles have pro-environmental advantages compared to traditional automobiles, or even hybrids: they can help reducing pollution and noise levels locally, and greenhouse gas emissions globally. However, there are still many challenges that the electric vehicles must overcome before reaching level of diffusion that can have significant impact on sustainability. This paper evaluates combined sustainability of electric vehicle and small-scale energy production. We propose a framework for sustainable electric vehicle - energy prosumer integration and outline a policy mix that is needed to support adoption of both renewable energy technologies and electric vehicles.
AB - Electric vehicles have pro-environmental advantages compared to traditional automobiles, or even hybrids: they can help reducing pollution and noise levels locally, and greenhouse gas emissions globally. However, there are still many challenges that the electric vehicles must overcome before reaching level of diffusion that can have significant impact on sustainability. This paper evaluates combined sustainability of electric vehicle and small-scale energy production. We propose a framework for sustainable electric vehicle - energy prosumer integration and outline a policy mix that is needed to support adoption of both renewable energy technologies and electric vehicles.
KW - Electric vehicle
KW - Policy
KW - Prosumer
KW - Renewable energy
KW - Sustainable
U2 - 10.1109/ISGT-Asia.2017.8378406
DO - 10.1109/ISGT-Asia.2017.8378406
M3 - Conference contribution
SP - 1
EP - 6
BT - 2017 IEEE Innovative Smart Grid Technologies - Asia
PB - IEEE
ER -
TY - GEN
T1 - Towards the deployment of cloud robotics at factory shop floors
T2 - A prototype for smart material handling
AU - Hussnain, Ali
AU - Ferrer, Borja Ramis
AU - Lastra, Jose L.Martinez
N1 - INT=aut,"Hussnain, Ali"
PY - 2018/6/15
Y1 - 2018/6/15
N2 - The evolution of industries and their needs towards the implementation of Industry 4.0 based systems has brought both new technological challenges and opportunities. This article proposes the adoption and deployment of cloud robotics at factories to enhance the control and monitoring of processes, such as handling materials multiple assemblies in single cells. The ultimate research objective of this research is the offloading computation and integrating cloud robotics into an industrial scenario. However, the investigation of state of the art techniques, tools and technologies, and the development of functional prototypes is beforehand required. Then, this article presents a small-scale system as a prototype that employs the Google cloud vision API as a resource that, in turn, is used by networked agents for supporting the decision-making in the process of handling material commodities at factory shop floor. The overall concept as well as the interaction between the main actors of the prototype is detailed. Finally, further research directions are discussed.
AB - The evolution of industries and their needs towards the implementation of Industry 4.0 based systems has brought both new technological challenges and opportunities. This article proposes the adoption and deployment of cloud robotics at factories to enhance the control and monitoring of processes, such as handling materials multiple assemblies in single cells. The ultimate research objective of this research is the offloading computation and integrating cloud robotics into an industrial scenario. However, the investigation of state of the art techniques, tools and technologies, and the development of functional prototypes is beforehand required. Then, this article presents a small-scale system as a prototype that employs the Google cloud vision API as a resource that, in turn, is used by networked agents for supporting the decision-making in the process of handling material commodities at factory shop floor. The overall concept as well as the interaction between the main actors of the prototype is detailed. Finally, further research directions are discussed.
KW - Cloud Robotics
KW - Industrial Cyber-Physical Systems
KW - Industry 4.0
KW - Multi-Agent Systems
KW - SOA
U2 - 10.1109/ICPHYS.2018.8387635
DO - 10.1109/ICPHYS.2018.8387635
M3 - Conference contribution
SP - 44
EP - 50
BT - 2018 IEEE Industrial Cyber-Physical Systems, ICPS 2018
PB - IEEE
ER -
TY - GEN
T1 - Visibility-Aware Part Coding for Vehicle Viewing Angle Estimation
AU - Yang, Dan
AU - Qian, Yanlin
AU - Cai, Dingding
AU - Yan, Song
AU - Kämäräinen, Joni-Kristian
AU - Chen, Ke
N1 - EXT="Chen, Ke"
jufoid=79229
PY - 2019/8/1
Y1 - 2019/8/1
N2 - A number of spatially-localised semantic parts of vehicles sensitive to pose changes are encoded their visible probabilities into a mid-level feature vector. Car pose estimation is then formulated into a regression on concatenated low-and mid-level features to continuously changing viewing angles. Each dimension of our visibility-Aware part codes separates all the training samples into two groups according to its visual existence in images, which provides additional part-specific range constraint of viewing angles. Moreover, the proposed codes can alleviate the suffering from sparse and imbalanced data distribution in the light of modelling latent dependency across angle targets. Experimental evaluation for car pose estimation on the EPFL Multi-View Car benchmark demonstrates significant improvement of our method over the state-of-The-Art regression methods, especially when only sparse and imbalanced data is available.
AB - A number of spatially-localised semantic parts of vehicles sensitive to pose changes are encoded their visible probabilities into a mid-level feature vector. Car pose estimation is then formulated into a regression on concatenated low-and mid-level features to continuously changing viewing angles. Each dimension of our visibility-Aware part codes separates all the training samples into two groups according to its visual existence in images, which provides additional part-specific range constraint of viewing angles. Moreover, the proposed codes can alleviate the suffering from sparse and imbalanced data distribution in the light of modelling latent dependency across angle targets. Experimental evaluation for car pose estimation on the EPFL Multi-View Car benchmark demonstrates significant improvement of our method over the state-of-The-Art regression methods, especially when only sparse and imbalanced data is available.
KW - Car pose estimation
KW - Coding
KW - Pose-sensitive parts
KW - Regression forests
KW - Visibility-Aware
U2 - 10.1109/ICIST.2019.8836907
DO - 10.1109/ICIST.2019.8836907
M3 - Conference contribution
SP - 65
EP - 70
BT - 9th International Conference on Information Science and Technology, ICIST 2019
PB - IEEE
ER -
TY - CONF
T1 - A reformulation of the internal model principle using factorization approach
AU - Laakkonen, Alpo Antti Petteri
PY - 2017
Y1 - 2017
M3 - Paper, poster or abstract
ER -
TY - JOUR
T1 - Dynamic modeling and analysis of PCM-controlled DCM-operating buck converters-A reexamination
AU - Suntio, Teuvo
PY - 2018
Y1 - 2018
N2 - Peak-current-mode (PCM) control was proposed in 1978. The observed peculiar behavior caused by the application of PCM-control in the behavior of a switched-mode converter, which operates in continuous conduction mode (CCM), has led to a multitude of attempts to capture the dynamics associated to it. Only a few similar models have been published for a PCM-controlled converter, which operates in discontinuous conduction mode (DCM). PCM modeling is actually an extension of the modeling of direct-duty-ratio (DDR) or voltage-mode (VM) control, where the perturbed duty ratio is replaced by proper duty-ratio constraints. The modeling technique, which produces accurate PCM models in DCM, is developed in early 2000s. The given small-signal models are, however, load-resistor affected, which hides the real dynamic behavior of the associated converter. The objectives of this paper are as follows: (i) proving the accuracy of the modeling method published in 2001, (ii) performing a comprehensive dynamic analysis in order to reveal the real dynamics of the buck converter under PCM control in DCM, (iii) providing a method to improve the high-frequency accuracy of the small-signal models, and (iv) developing control-engineering-type block diagrams to facilitate the development of generalized transfer functions, which are applicable for PCM-controlled DCM-operated buck, boost, and buck-boost converters.
AB - Peak-current-mode (PCM) control was proposed in 1978. The observed peculiar behavior caused by the application of PCM-control in the behavior of a switched-mode converter, which operates in continuous conduction mode (CCM), has led to a multitude of attempts to capture the dynamics associated to it. Only a few similar models have been published for a PCM-controlled converter, which operates in discontinuous conduction mode (DCM). PCM modeling is actually an extension of the modeling of direct-duty-ratio (DDR) or voltage-mode (VM) control, where the perturbed duty ratio is replaced by proper duty-ratio constraints. The modeling technique, which produces accurate PCM models in DCM, is developed in early 2000s. The given small-signal models are, however, load-resistor affected, which hides the real dynamic behavior of the associated converter. The objectives of this paper are as follows: (i) proving the accuracy of the modeling method published in 2001, (ii) performing a comprehensive dynamic analysis in order to reveal the real dynamics of the buck converter under PCM control in DCM, (iii) providing a method to improve the high-frequency accuracy of the small-signal models, and (iv) developing control-engineering-type block diagrams to facilitate the development of generalized transfer functions, which are applicable for PCM-controlled DCM-operated buck, boost, and buck-boost converters.
KW - Discontinuous conduction mode
KW - Duty-ratio constraints
KW - Dynamic modeling
KW - Peak-current-mode control
U2 - 10.3390/en11051267
DO - 10.3390/en11051267
M3 - Review Article
VL - 11
SP - 1
EP - 18
JO - Energies
JF - Energies
SN - 1996-1073
IS - 5
M1 - en11051267
ER -