Design and Experiment Evaluation of a Magneto-Rheological Damper for the Legged Robot

This paper proposes a Magneto-Rheological (MR)-based damper that can avoid high impulsive forces caused by the legged robot while walking and jumping. Traditional high stiffness system can ensure precise positioning of actuators, and accomplish repetitive tasks efficiently. Nevertheless, it has great hardness and is easy to cause impact, which seriously affects the stability of robot while walking and jumping. The previous approach to solve this problem adopt variable impedance actuators. They can absorb impact shock and store energy but typically have a very low intrinsic damping for efficient energy storage and retrieval. This paper introduces a novel MR-based damper that can change intrinsic damping by adjusting the current in the coil. The models of this damper are established and several experiments are carried out to test its performance. The results show that it can change the internal Magneto-Rheological Fluid (MRF) to absorb impact effectively.