Predefined-Time Trajectory Planning for a Dual-Arm Free-Floating Space Robot

Abstract

In space mission, the tracking accuracy of robot will be affected by many factors. Fortunately, some errors can be eliminated by trajectory planning without the need for additional fuel, hence, in this paper, a nonsingular error-free trajectory planning method for a dual-arm free-floating space robot(FFSR) will is studied with the large initial measurement errors and non-zero dynamic of base. Firstly, the pose error kinematic equation is deduced by the desired pose command and related kinematics. Then, a predefined-time stability function is used as the pose-feedback control law to converge the error to zero, and the convergence time is bounded. In the end, the motion trajectory of balance arm will be planned by the momentum conservation equations of the system to offset the dynamic coupling. The predefined-time stability theorem will significantly improve the anti-disturbance performance of the traditional pose-feedback based trajectory planning method, and the error can be eliminated within any required task time. Simulation results validate the effectiveness of the proposed methodology.