ヒト腕の拘束到達運動機構に対する3関節腕最適制御モデルの構築

抄録

This research extends the three-joint arm's optimal control model with a freezing-like mechanism in its hand joint to an advanced model that simulates hand-joint constrained reaching movement and is more analogous to the human three-joint arm's motion control mechanism, and it discusses its effectiveness. Actually, the advanced model is achieved by changing the desired value of its state variable at the final point from joint angle information to visual one (i.e., x and y coordinates of the hand point) and predicting its hand posture angles at the final point from ones acquired as visual information. Consequently, the following results are obtained: (1) there exists a linear relationship between hand posture angles acquired as visual information and ones measured experimentally at the final point; (2) the advanced model reproduces human arm's hand-joint constrained reaching movement characteristics; (3) for the advanced model's success in reproducing hand-joint constrained reaching movements, the model requires a larger weight value of the energy term in its criterion function than the previous model so that it can enhance the degree of consumed energy minimization of the advanced model. These results suggest that the advanced model can be effective in simulating hand-joint constrained reaching movements and can become a mathematical model more analogous to the human three-joint arm's motion control mechanism, and that there is a stronger possibility that human reaching movements can be generated based on consumed energy minimization.