Dynamics and control of space robot brachiating motion using handrails

We investigate brachiating motion dynamics and control of space robot using handrails on in-orbit structures in order to inspect, repair and/or construct them. We deal with one arm type space robot based on the Reconfigurable Brachiating space Robot (RBR). We conduct a micro-gravity flight experiment of the RBR, and we identify kinematical and dynamical parameters of the robot arm. Then, we conduct numerical simulations of 6 DOF robot arm dynamics under the constraint within a two-dimensional plane. It is assumed that the robot arm moves on a large space structure using handrails attached to the structure. When the handrail slowly vibrates due to flexibility of the large structure, then the robot behavior is influenced by its fluctuation. In this paper, we show the simulation results of brachiating motion and discuss the flexibility effects to the robot motion.