Control of biomimetic robots based on analysis of human arm trajectories in 3D movements

Abstract

In this study, a biomimetic robot arm with joint redundancy movable in a three-dimensional space is taken into consideration. The basic trajectories for controlling all joints are formulated under the minimum angular jerk criterion. Then, a time adjustment of the joint motion of the elbow relative to the shoulder is provided for representing specific properties of joint angular trajectories during a movement. Here, a systematical scheme for formulating the human-like trajectory has been developed by use of a direct kinematics. As the angular trajectories of all joints can be formulated in the proposed manner, the hand trajectory can be uniquely produced once the initial and final postures of the arm and a movement duration are given. The trajectories under the proposed scheme are produced by utilizing the same movement conditions observed by experiments. Then, performance for reproducing human-like trajectories has been evaluated under the comparative analysis between the observed and the produced trajectories.