Kinematics Analysis of Free-Floating Redundant Space Manipulator based on Momentum Conservation

Abstract: This paper focuses on the kinematics analysis of free-floating space redundant manipulator at velocity level based on the momentum conservation law. Firstly, a general solution for inverse kinematics is proposed based on the concept of task priority. Secondly, in terms of pseudo-inverse and null-space components of the inertia matrix, the manipulator Jacobian matrix and the generalized Jacobian matrix, four different solutions of inverse kinematics at velocity level are derived when only the base orientation is taken into account. Thirdly, using these solutions, a number of space tasks can be completed by using corresponding inverse kinematics solution, which can give us a deeper understanding of the complex system’s motion in space environment. Finally, fixed attitude restricted (FAR) motion and fixed end-effector restricted (FER) motion are proposed to complete the specific space mission by using the redundancy of the manipulator. Through singular-value decomposition, the dexterity measures of FAR and FER motions are derived. The proposed inverse kinematics formulations will be of great value for the future space applications.