Impedance-based Foot-end Torque Vibration Isolation Control of Parallel Structure Wheel-legged Robot

Vibration isolation control is a major challenge for the wheeled motion of hexapod robot in unknown terrain, especially when the ground will produce disturbing torque on the foot-end. In this paper, a torque vibration isolation control method based on impedance is proposed to counteract the disturbance torque at the foot-end of the robot during wheel motion. Firstly, the kinematics model of the robot single leg Stewart platform is introduced, and the kinematics formula of the foot rotating around the X-axis of its tip center is derived. Secondly, a torque impedance algorithm with torque as input and foot attitude angle as output is established. Finally, the joint simulation based on Python and V-rep is carried out. The simulation results show that the disturbance torque at the foot-end can be largely offset by the torque impedance control method, which improves the stability of the fuselage attitude, and verifies the effectiveness of the algorithm.