Research on Compliance Control for the single Joint of a Hydraulic Legged Robot

Compliance controller for the single joint of a hydraulic legged robot is presented in this paper. This method combines the active compliance controller of the impedance controller based on force control with the passive compliance of the Series Elastic Actuator (SEA) to achieve a compliant control function for a wide range of variable impedances and rapid response to load changes. The performance of this controller was assessed on a single joint hydraulic legged robot which has already been modelled. An experiment platform with double hydraulic drive units was designed for testing the force tracking performance of the hydraulic drive units. The experimental results have shown that the control method is reasonable and the system has a good performance of impact resistance and active compliance.