Motion planning of a free-flying space robot system under end effector task constraints

Abstract

This study focuses on the motion planning of a free-flying space robot system with non-conserved linear and angular momentums due to thrusts acting on its base. The system model is established at the kinematic level based on the momentum theorem, which takes into account the change in base mass. In particular, a motion planning strategy is proposed to perform trajectory tracking of the end effector for the free-flying space robot. The thrusts and torque acting on base satellite are not predefined, but are taken as system control inputs to be optimized, as are joint accelerations. Therefore, the synchronous motion planning of the base satellite and manipulator is formulated as an open-loop optimization problem, which is subject to physical constraints such as thrust and torque saturation, joint motion limitations, and collision avoidance, etc. Finally, the system under different task constraints of end effectors is numerically simulated to demonstrate the effectiveness of the proposed method.