Three-Joint Arm's Optimal Control Model for Simulating Human Arm's Violin-Bowing Movements

Abstract

This sample was prepared using MS-word. This research formulates an optima control model for simulating violin bowing-like movements, a kind of human arm's constrained reaching movements, which are characterized by nearly straight hand paths, and discusses the strategy underlying the human arm’s motion control mechanism through examining the model’s effectiveness. Actually, a constrained condition that evaluates linearity of the hand point is incorporated into the criterion function of the previous three-joint arm’s minimum energy model with a freezing-like mechanism in its hand joint. Consequently, the following results are obtained: (1) the experimentally-measured hand-joint angle changes quite a bit during constrained reaching movements contrary to unconstrained reaching movements; (2) the newly introduced hand-point linearity evaluating term makes the hand path get close to the straight line connecting the start and target points; (3) the constrained reaching movements reproduced by the proposed model agree well with those measured. The above results suggest that the proposed model is effective in simulating violin bowing-like movements, and that the human arm’s motion control mechanism can be subject to some energy minimizing strategy.