SIMULATION OF WHOLE-BODY FAST REACHING MOVEMENTS

Abstract

Whole-body fast reaching motions were simulated using a planar model with seven segments. Model movements were driven by joint torque generators and optimized for achieving the desired final posture within the shortest amount of time. Optimally simulated motion roughly matched the actual movement. It was found that the front hip joint activated first, followed by the rear hip joint, both lasting for only a short period. The rear knee joint extended to generate propulsion force in the middle and late phase of the motion. Contrary to common intuitions, the stretching arm motion was primarily driven by the rest of the body segments passively instead of activating actively. This might be explained by constraining motions (especially of the lower body) in two dimensions and fixating the rear arm on the trunk.