Research on a Centralized Controller for the Two-Stage Supply Pressure Valve-Controlled Cylinder System with Energy Recovery

This paper presents the design of a centralized controller aimed at enhancing energy efficiency in hydraulic actuation systems for legged robots. Firstly, a centralized controller has been designed for the Two-Stage Supply Pressure Valve-Controlled Cylinder system. It can control seven threaded cartridge proportional directional valves simultaneously to enable energy-efficient actuation of hydraulic cylinder. Secondly, the controller can adapt different control strategy according to the current working conditions. Moreover, the controller utilizes a closed-loop feedback system for hydraulic cylinder positioning, ensuring high precision in position control. To further enhance response speed, an inverse discharge drive circuit is employed for the proportional directional valves. Finally, experimental results demonstrate the controller’s position control accuracy and energy efficiency. With a control bandwidth of 4.1 Hz and the ability to recover up to 13.37 J of energy per movement during energy recovery state, this study provides a more efficient and responsive solution for advancing hydraulic actuation in legged robotic systems.