Research on Dead Zone Compensation Adaptive Control of Electro-Hydraulic Proportional Position Servo Control Systems

The electro-hydraulic proportional control system is characterized by inherent nonlinearity, time variability, variable flow dead zones, and variable flow gain, all of which significantly impact the accuracy of position control. To address the challenges posed by nonlinearity, parameter uncertainties, and external disturbances, this paper proposes an adaptive control algorithm that does not rely strictly on a precise mathematical model of the system, demonstrating robust anti-disturbance capabilities. To specifically tackle the dead zone characteristics of the system, a fuzzy-based dead zone compensation algorithm has been designed to adjust the compensation amount in real time, based on both the error and the rate of change of the error. The integration of the adaptive control algorithm with the fuzzy-based dead zone compensation has markedly improved the dynamic characteristics of the system, leading to enhanced control performance. Experimental results reveal that, in the absence of the fuzzy-based dead zone compensation, the system experiences significant lag in position tracking, with maximum position tracking errors reaching up to 6 mm. However, when both the adaptive control algorithm and the fuzzy-based dead zone compensation algorithm are applied simultaneously, the control performance is significantly enhanced, achieving a maximum position tracking error of less than 1 mm once the system stabilizes its tracking.