Adaptive Output Feedback Prescribed Performance Control for Hydraulic Systems with Disturbance Compensation

针对液压系统中存在的匹配和不匹配干扰共存的问题，兼顾瞬态性能和稳态性能需求，提出了一种自适应鲁棒规定性能控制器。以阀控电液位置伺服系统为例，建立了包含匹配和不匹配干扰共存的系统非线性数学模型，定义预设性能函数规划控制误差，基于规划后的转换误差设计反步控制器，并通过反步法将自适应控制与扩展滑模观测器有效地结合在一起，实现对匹配和不匹配干扰的前馈补偿，获得了可预设的瞬态性能和渐进稳态性能。此外，还利用Lyapunov理论分析了闭环系统的稳定性。最后，通过对比仿真结果验证了所提控制策略的控制性能。Addressing the coexistence of matched and mismatched disturbances in hydraulic systems while simultaneously considering transient and steady-state performance requirements, an adaptive robust prescribed performance controller (ARPPC) is proposed. Taking a valve-controlled electro-hydraulic position servo system as an example, a nonlinear mathematical model of the system incorporating both matched and mismatched disturbances is established. A prescribed performance function is defined to govern the control error, and a backstepping controller is designed based on the transformed error resulting from the prescribed performance function. An extended sliding mode observer (ESMO) is effectively integrated with adaptive control within the backstepping framework to achieve feedforward compensation for both matched and mismatched disturbances, ensuring pre-definable transient performance and asymptotic steady-state performance. Furthermore, the stability of the closed-loop system is analyzed using Lyapunov theory. Finally, comparative simulation results are presented to validate the effectiveness of the proposed control strategy.