Position control for a hydraulic loading system using the adaptive backsliding control method

A valve-controlled asymmetric cylinder loading system was taken as the research object in this study. To solve the problems existing in electro-hydraulic servo loading systems, such as low loading accuracy, interference from the external environment, and strong nonlinear, time-variant, and uncertain parameters in position control, a position control strategy for valve-controlled cylinders, based on the adaptive backsliding control method, is proposed. The system was divided into several subsystems, then, the stability of each subsystem was guaranteed by the Lyapunov stability criterion, and the unknown parameters of the system were expressed by known parameters to ensure stability. To conduct experimental verification, a set of valve-controlled asymmetric cylinder loading system hardware-in-a-loop platform is designed based on the xPC Target realtime control kernel in MATLAB, and the application of complex control algorithms is realized in engineering systems. Through experiments and simulations, the effectiveness of the control method is verified. During 2-Hz sinusoidal tracking, the maximum deviation for the adaptive controller was reduced by 47.7% from that for a PID controller, and the phase lag was smaller. The results show that the adaptive backsliding control method is effective, and the research results are of great significance to the high performance control of hydraulic loading system and the engineering application of complex algorithms.