非ホロノミック拘束下における到達運動としての鉄棒でのけ上がり運動の解析

Abstract

The criteria that explain the hand reaching movements of the human, based on the framework of the optimization problem, have a possibility of being applied to the other complex movements. In this paper, we attempt to explain a basic gymnastic maneuver on the horizontal bar, referred to as the kip motion, as a difficult goal-directed movement under a nonholonomic constraint. First, we show the results of the motion measurement of the kip motion performed by expert gymnasts, where the motions of each subject are very similar among the trials. Second, we construct a model of the gymnast performing the kip motion as a rigid 3-link with an unactuated joint at the hand and actuated joints at the shoulder and the hip, where the angle profiles of the actuated joints are approximated by fifth spline functions. Moreover, it is confirmed that the model's motion is approximately consistent with the measured motion. Third, by using the above model, the kip motion connecting the initial, via-, and final posture is generated with the minimum torque change criterion, which is known to explain the hand reaching movements. The results of the numerical analysis show that various kip motions are generated depending on imposed via-postures, and a very similar motion to the measured data is generated when an appropriate via-posture is imposed for each subject. The results suggest that the motion generation of the kip movements and the hand reaching movements could be understood by using a common criterion.