TY - JOUR
T1 - Augmented inertial measurements for analysis of javelin throwing mechanics
AU - Särkkä, Olli
AU - Nieminen, Tuukka
AU - Suuriniemi, Saku
AU - Kettunen, Lauri
PY - 2016/11/13
Y1 - 2016/11/13
N2 - This paper examines the exploitation of inertial
measurements to analyze javelin throwing mechanics. The
main objective was to demonstrate that consumer-grade
inertial navigation systems, augmented with some position
and attitude data obtained from a video sequence, yield
detailed information of the mechanics of javelin throwing.
Especially, such a system makes it possible to analyze the
momentary force and power exerted on the javelin during
the acceleration phase. Although the presented system is a
pilot, leaving space for further improvements, it already
reveals the potential of inertial navigation systems to
sports. In practise, an inertial measurement unit was
embedded inside the tip of the javelin to determine the
javelin’s momentary attitude, position, and velocity.
Graphs on the speed and angular velocity about the lon-
gitudinal axis of the javelin during the whole performance
are presented. The maximum estimated release speed and
release angular speed were 28.02 m/s and 215.9 rad/s,
respectively. The acceleration phase trajectory of the
javelin and its deviation from a straight line path are
demonstrated. Additionally, the momentary forces and
powers are shown and the effect of aerodynamic forces on
the projectile is speciﬁed. The magnitude of the maximum
tangential forces and accelerating powers were 364 N and
9.76 kW. The duration and length of the acceleration phase
trajectory varied between 223 and 231 ms, and 2.48 and
2.75 m. To estimate the accuracy of the inertial measurements, the acceleration phase results were compared to
measurements made with high-speed cameras.
AB - This paper examines the exploitation of inertial
measurements to analyze javelin throwing mechanics. The
main objective was to demonstrate that consumer-grade
inertial navigation systems, augmented with some position
and attitude data obtained from a video sequence, yield
detailed information of the mechanics of javelin throwing.
Especially, such a system makes it possible to analyze the
momentary force and power exerted on the javelin during
the acceleration phase. Although the presented system is a
pilot, leaving space for further improvements, it already
reveals the potential of inertial navigation systems to
sports. In practise, an inertial measurement unit was
embedded inside the tip of the javelin to determine the
javelin’s momentary attitude, position, and velocity.
Graphs on the speed and angular velocity about the lon-
gitudinal axis of the javelin during the whole performance
are presented. The maximum estimated release speed and
release angular speed were 28.02 m/s and 215.9 rad/s,
respectively. The acceleration phase trajectory of the
javelin and its deviation from a straight line path are
demonstrated. Additionally, the momentary forces and
powers are shown and the effect of aerodynamic forces on
the projectile is speciﬁed. The magnitude of the maximum
tangential forces and accelerating powers were 364 N and
9.76 kW. The duration and length of the acceleration phase
trajectory varied between 223 and 231 ms, and 2.48 and
2.75 m. To estimate the accuracy of the inertial measurements, the acceleration phase results were compared to
measurements made with high-speed cameras.
KW - Time-parametrized trajectory
KW - Force
KW - Work
KW - Power
KW - Inertial navigation
U2 - 10.1007/s12283-016-0194-x
DO - 10.1007/s12283-016-0194-x
M3 - Article
SP - 219
EP - 227
JO - Sports Engineering
JF - Sports Engineering
SN - 1369-7072
ER -