Bio-inspired Trajectory Planning for Robot Catching Movements Based on Tau Theory

Abstract

A bio-inspired trajectory planning method for robot reaching movement to catch an object is presented. The method is based on the Tau theory which has been established by cognitive science researchers from studying the natural motion patterns when animals(including humans) approaching and catching a target object. Based on the Tau theory, two fundamental motion strategies, namely, the Tau coupling strategy and the intrinsic Tau-g guidance strategy have been analyzed. In order to solve the problem that the initial acceleration value is nonzero in the intrinsic Tau-g guidance strategy, a new strategy, namely, the intrinsic constant jerk Tau guidance strategy is presented. The trajectory planning formulae based on the Tau theory are derived. Trajectory planning, kinetics analysis, dynamic analysis, computer simulation and experiments are performed on a 3-DOF planar manipulator. The results show that, by using the proposed method, the end-effector can achieve reaching the target position and attitude at the same definite time with good continuity of joint velocity and acceleration, and the trajectory in Cartesian space is a straight path with a smooth bell-shaped velocity profile.