Abstract:This paper studies the dynamics of a space manipulator. The space manipulator is designed for precise on-orbit servicing missions in a highly constrained environment. First, this paper proposes a dynamic model of the manipulator. The manipulator is modeled as a rigid multibody system and the ropes are assumed to be massless and linear elastic. The equations of motion are derived using space operator algebra. Then, this paper studies the computational efficiency of numerical simulation. The governing equations of vibration are derived by perturbation method and the values of natural frequencies are calculated. The value of the upper bound of time step is calculated based on the stability region of numerical methods of ordinary differential equations. The computational efficiency of the numerical simulation is limited by the value of the upper bound. Two modifications of the dynamic model are introduced to relax the upper bound of the time step. The results of numerical examples show that the computational efficiency is improved by over two hundred times and real-time simulation is realized.