Design, Development and Control of the Hydraulic Walking Robot WLBOT

This paper focus on the system design and control of a quadruped robot WLBOT, which is used to conduct experiments and validate results in the field of hydraulic walking robot. Firstly, the mechanical structure of the WLBOT and a 3-DOF mammal leg structure actuated by hydraulic cylinders is proposed. Secondly, the onboard hydraulic system and a hierarchical-distributed control system is designed to meet the motion requirement of the robot. Then, a PID controller with velocity compensation is designed, and the joint velocity is derived by super-twisting observer. Finally, the experiments are taken on the WLBOT platform to test the performance of the controller. The position tracking error of the joints is nearly half of the non-compensated controller. The walking experiment results show that WLBOT has good controlled performance and walking ability.