Dynamic Transition Trajectory Planning of Three-DOF Cable-Suspended Parallel Robots

Abstract

This paper proposes a dynamic transition trajectory planning technique for three-degree-of-freedom (three-DOF) cable-suspended parallel robots (CSPRs). This trajectory is designed to connect multiple target trajectories beyond the static workspace in sequence with different starting points, as well as having the ability of starting from/ending with a resting position, while ensuring continuity up to the acceleration level. Two consecutive target trajectories are involved in the transition trajectory by using proper time functions, such that a goal trajectory is gradually reached by approaching the amplitude parameters and frequencies from those of a source trajectory. Additionally, each transition is based on the optimization of THE departure point from its source trajectory and a minimum time for the transition to its goal trajectory. An example is provided to demonstrate the novel trajectory-planning technique. The robot is requested to start from the state of rest, merge into two consecutive ellipses, a straight line and a circle in sequence and then go back to the state of rest.