Adaptive Sliding Mode Control of an Electro-Hydraulic Actuator With a Kalman Extended State Observer

Electro-hydraulic actuators (EHAs) are key linear drive components in various industrial applications. This paper addresses the challenge of achieving precise displacement tracking control for EHAs with only noisy displacement measurements. We propose a novel control approach, which consists of a Kalman extended state observer (KESO) with an adaptive sliding mode controller (ASMC). First, compared to the conventional high-gain design for the extended state observer (ESO), the Kalman filtering technique is utilized to tune the ESO feedback gain, effectively mitigating observation failures caused by measurement noise. Second, to ensure stability and minimize tracking errors in sliding mode control, a switching-gain adaptation is designed based on the desired switching gain via the derivative of the sliding variable. To validate the effectiveness of the proposed approach, simulation experiments are conducted in the Amesim simulation software. The results conclusively demonstrate that the proposed KESO-ASMC achieves significantly improved trajectory tracking performance, even in the presence of measurement noise and unknown disturbances.