Development of Upper Limb Simulation Model for Racket Shaft Designing in Badminton Swing Motion

Abstract

The purpose of this study is to quantify the effects of various factors on player performance and to obtain useful suggestions for racket designing by constructing a three-dimensional simulation model of badminton swing motion. The racket model consists of a shaft section divided into four rigid segments, with virtual joints with rotational springs between adjacent segments, and elastic torques acting in response to angular displacement and angular velocity to represent shaft bending. For the upper limb, the hand, forearm, and upper arm were modeled as a three-segment rigid body model. The torque acting on the virtual joints of each joint and grip section is controlled by PD control, which sets the control gain according to the joint angle and angular velocity calculated based on the observed values for the input joint torque, to obtain a joint torque reduces the error between the motion generated by the simulation and the actual motion. The results obtained from the simulations, effects of shaft design factors on various evaluation quantities were calculated. Regarding the validity of the model, although the obtained model represented the racket head speed during the swing well, it was observed that the error near impact was larger than that of the actual measurement.