Trajectory Planning for Redundant Robotic Manipulators with Constrained Joint Space

Abstract

This research is focused on trajectory planning for redundant robotic manipulators with constrained joint space. The redundant robots have infinite number of solutions of the inverse kinematics problem. Due to the constrained joint space, the number of sets of joint angles attaining given end-effector position are limited. This requires passing through singularities when trajectory movement is executed. Each pass through a singularity increases the execution time. This paper takes into consideration the characteristics of both the desired trajectory and the robotic manipulator. It proposes an algorithm which discretizes the desired trajectory and constructs a weighted directed graph which represents all the possible ways for planning the trajectory movement. The trajectory movement with the minimum execution time can then be planned by finding the path with minimum cost of the constructed graph. The applicability of the algorithm is evaluated through experiments.