Improved Active Disturbance Rejection Control and Parameter Setting for Position Tracking of Active Suspension Electro-Hydraulic Servo Actuator

An improved active disturbance rejection position control method is proposed to address the problems of nonlinearity, model uncertainty, and difficulty in controller parameter setting in a vehicle's active suspension electrohydraulic servo actuator (ASEHSA). The method proposed consists of an improved extended state observer (IESO), a linear combination control law, and the known dynamic model of the ASEHSA. The overall disturbance in improved linear active disturbance rejection control (ILADRC) is decomposed into the known dynamic model of the system and unknown disturbance. Through three-state feedback control and system model derivation, the unknown setting parameters of the third-order ILADRC are reduced to only one unknown parameter, effectively reducing the difficulty of control parameter selection. The pivotal innovation of this method is the design of a third-order linear active disturbance rejection controller for the ASEHSA, along with the parameter setting method for this controller. Mathematical proofs are provided to demonstrate the convergence of the IESO and the stability of the closed-loop control system. Finally, the effectiveness of the proposed method is verified by simulation and experimental testing.