Energy-Efficient Control of Pneumatic Muscle Actuated Biped Robot Joints

Due to its muscle-like properties, PMA (pneumatic muscle actuator) is more suitable than geared servomotors to be used as the actuator for biped robots. In this paper, a novel pressure control method for PMA actuated biped robot joints is proposed. The method is able to reduce the energy/air consumption of the joint trajectory tracking process based on adaptation of the joint stiffness. To determine the stiffness value of the joint, a frequency analysis was conducted. The pressures of the muscles were derived uniquely using the stiffness value as a constraint. Then the energy-efficient trajectory tracking was archived using the derived pressures to control the joint motion. The simulation and experiment results show that the energy/air consumption is reduced by the proposed method.