Output Feedback Control of Dual Valve Electro-Hydraulic Valve Based on Cascade Structure Extended State Observer Systems with Disturbance Compensation

To address the performance degradation of standard linear extended state observers (LESO) caused by severe peaking phenomena with increasing system order, which compromises controller accuracy, this paper proposes an innovative output feedback controller using a cascaded observer structure. Through the uniform exponential stability (UES) criterion, we demonstrate that the proposed observer guarantees bounded tracking errors for system states. A novel approach constructs desired load pressure from reference trajectories, effectively decoupling the nonlinear interactions between actual load pressure and input signals. By integrating backstepping control methodology with Lyapunov stability analysis, we develop a robust output feedback controller. Extensive simulations validate the proposed controller's effectiveness, extensive simulations validated the effectiveness of the proposed controller, in all four test scenarios, the tracking errors of the proposed controller were reduced by approximately 10% to 61.5% compared to LESO, regarding external disturbance estimation, the estimation accuracy was approximately twice that of LESO.