A High-Precision Motion Control Strategy for Valve-Controlled Cylinders

Valve-controlled cylinder serves as a key component in electro-hydraulic servo systems, and its motion precision is pivotal to the system’s stability, responsiveness, and final positioning accuracy. However, valve-controlled cylinder systems often encounter challenges in practical operation, such as complex nonlinear friction, parameter uncertainties, and external load disturbances, which make it difficult for conventional control strategies to meet the stringent requirements of high-precision positioning. Proportional-integral-derivative(PID) control suffers from insufficient robustness when dealing with strong nonlinearities and parameter variations, making it prone to overshoot or steady-state errors. In contrast, although sliding mode control(SMC) offers strong robustness, its inherent chattering phenomenon exacerbates mechanical wear and impairs positioning accuracy. To overcome this technical bottleneck, this paper proposed an advanced adaptive robust control(ARC) strategy incorporating a fast dynamics compensation term and a nonlinear robust feedback term. To validate the effectiveness and superiority of the proposed strategy, comprehensive comparative simulation analyses were conducted. The results demonstrate that compared with traditional PID control and SMC, the designed adaptive robust controller significantly improves the trajectory tracking accuracy, dynamic response, and disturbance rejection capability of the valve-controlled cylinder system, achieving superior control performance.