Research on Position Recognition and Control Method of Single-leg Joint of Hydraulic Quadruped Robot

In order to obtain the precise mathematical model of the position control system of the hydraulic quadruped robot, and to meet the requirements of the system parameters in different stages of motion, this paper studies the position control system of the single-leg joint of the hydraulic quadruped robot: First of all, this paper uses the closed-loop indirect identification method to identify the position of the leg joints of the hydraulic quadruped robot to obtain the mathematical model of the system; And then, the speed PID control algorithm and speed planning algorithm are designed, so that the system can quickly respond to the changes of system input according to the requirements of different speeds; Finally, the joint position control system of the hydraulic quadruped robot is simulated and verified by experiments. Background: The mathematical model of the positioning system of the hydraulic quadruped robot is clear, but the parameters in the model have the characteristics of uncertainty and time-variation. In the joint position control system of a hydraulic quadruped robot, different motion stages have different requirements for system parameters. Objective: The purpose of this study is to obtain the precise mathematical model of the position control system of the hydraulic quadruped robot and to meet the requirements of the system parameters in different stages of motion. Methods: This research takes the hydraulic quadruped robot single-leg system as the research object and uses the closed-loop indirect identification method to identify the position of the leg joints of the hydraulic quadruped robot to obtain the mathematical model of the system. Then, the speed PID control method is designed and compared with the ordinary PID control by taking the positioning control accuracy of the robot before touching the ground as a standard to carry out the controlled trial. Results: In this research, the identification method and control algorithm are designed, and finally, the simulation and experimental research are carried out. The results of the simulation and experiment verify the correctness of the identification method and the effectiveness of the control algorithm. Conclusion: First of all, this paper uses the closed-loop indirect identification method to identify the position of the leg joints of the hydraulic quadruped robot to obtain the mathematical model of the system. Then, the speed PID control algorithm and speed planning algorithm are designed so that the system can quickly respond to the changes of system input according to the requirements of different speeds.