Onboard hydraulic system controller design for quadruped robot driven by gasoline engine

Featuring small size, low weight and high energy density, the hydraulic system driven by gasoline engine is an ideal solution for the actuation system of large quadruped robots. This paper studies the quadruped robot SCalf-III(SDU Calf-III) and designs a controller for the hydraulic system, which is based on the characteristics of the onboard hydraulic system and the requirements of the robot motions. The working conditions of the hydraulic system are confirmed on the basis of the robot power consumption. An engine speed control strategy is designed using the sectional PI algorithm, where the fuzzy control is implemented in the feed-forward loop. The hardware and the software designs of the controller are demonstrated, where the engine controlling and hydraulic system monitoring are implemented. Experiments on the SCalf-III robot show that the designed controller could control the engine rotating speed effectively, and ensure adequate hydraulic power for the robot.