Reconfiguration of joint locked hyper-redundant space manipulator

Abstract

This paper presents a strategy for the reconfigurable robot exploiting redundancy of 6 DOF planar space robot. The space robots are frequently used to maneuver in harsh environments. The extreme nature of these environments increases the likelihood of robot failure. In this case, the robot reconfiguration becomes a necessity for smooth motion planning. To facilitate the robot to be reconfigured, each joint of the space robot is equipped with actuator and sensor. At a time, only two joints are actuatable while others are kept inactive temporarily to prevent its undesired movement through Proportional Derivative (PD) controller. These unactuated joints are proposed to be in use when healthy joints got locked due to actuator failure. The proposed reconfigurable robot can offer a simpler and more effective solution to maneuver in a small volume. The simulation and the animation results validate two case studies. Each case study includes motion planning of space robot when one joint suffers joint locked failure at some stage in manipulation and its reconfiguration. The bond graph technique has been used for the dynamic model of the system and generating system equations.