Adaptive Sliding Mode Control of a Nonlinear Electro-hydraulic Servo System for Position Tracking

Abstract

In view of the electro-hydraulic position servo system with parameter uncertainty and bounded disturbances, an improved adaptive sliding mode control scheme is proposed. The mathematical model of the valve-controlled system is first constructed with consideration of the external disturbance, matched and mismatched unknown parameters. Then, the parametric adaptive estimation laws are established by Lyapunov technique to estimate the generalized uncertainty parameters, and the discontinuous projection algorithm is used to ensure the boundedness of parameter estimation. In order to eliminate the chattering phenomenon in sliding mode control, the saturation function is designed to replace the sign function and the gain coefficient is adjustable on the sliding surface. Finally, the comparative experimental results clarify that the proposed control scheme has better control performance than the PID controller and the SMC controller.

Integral Nonsingular Terminal Sliding Mode Control of Hydraulic Servo Actuator Based on Extended State Observer

“…To validate the effectiveness of the proposed ESO-INTSM control strategy, TSM controller [33] and INTSM controller [41] are also conducted. It should be noted that parameters of these three controllers are well-tuned for the sake of best tracking performance.…”

“…As an effective tool to manage uncertainties and disturbance, sliding model controller suffers from the undesirable chattering phenomenon, which inevitably degrades the sliding accuracy [33,34]. Ma et al presented a fast terminal sliding mode (FTSM) tracking control for uncertain nonlinear systems with unknown parameters and system states combined with time-varying disturbances, which guarantees all tracking errors rapidly converge to the origin [35].…”

Position Deviation Control of Drilling Machine Using a Nonlinear Adaptive Backstepping Controller Based on a Disturbance Observer

“…In this study, a combined controller consisting of a nonlinear adaptive backstepping controller and a disturbance observer for deviation control was established and verified. Some studies have focused on controller design using the backstepping control method [22,26] and the disturbance observer method [23,31,32], which indicates that these methods are significant. However, most of the available research focuses on control accuracy using high-precision control elements.…”

“…The position control of the DCM can be partially realized using a conventional proportional-integral (PI) controller [19] and backstepping controller [20]. However, the DCM is a complex nonlinear system with parameter uncertainties, such as servo-valve and hydraulic actuator dynamics [21], stiffness and damping differences [22], and external disturbances such as friction between the rod and bore of hydraulic cylinders [23]. All these factors make it difficult to obtain satisfactory position coordination performance with the conventional PI controller and backstepping controller, because these two controllers cannot adjust their control parameters in consideration of the parameter uncertainties and external disturbances of the DCM.…”

Electro-hydraulic position servo system based on sliding mode active disturbance rejection compound control

“…[11][12][13] Sliding mode control(SMC) has the characteristics of rapid response speed, good robustness, insensitivity to changes in parameters and disturbances. 14 Currently, SMC is developed as high-gain observation controllers, 15 back-stepping recursive controllers, 16 parameter adaptive control laws 17 and nonlinear cascade controllers. 18 The emergence of these controllers has solved the problems of SMC parameter uncertainty, nonlinearity and disturbances.…”