Development and experimental validation of a reorientation algorithm for a free-floating serial manipulator

Abstract

This paper presents a method to reorient a free-floating serial manipulator using internal motion based on a path planning algorithm using a dynamic model of the manipulator and a potential function. Simulations with the proposed algorithm are performed using a nonlinear optimization technique in order to determine the actuator's velocity trajectories that achieve the reorientation. An example trajectory is presented in which a three-link planar robot starts from a pose in which all the links are aligned and ends with the same joint configuration but with the robot having completed a 180 degrees rotation. For this example, the algorithm finds trajectories that allow the robot to complete approximately 94% of the reorientation. To verify the simulation results against a real robot, a prototype of a planar robot with three bodies and two revolute joints is built. The experiments conducted show that the prototype is able to achieve the prescribed reorientation, even though the control of the orientation was implemented in an open-loop mode.