Sliding-Mode Active Disturbance Rejection Control for Electromagnetic Driven Compliant Micro-Positioning Platform

At the field of nanometer positioning and machining, high-precision tracking is a key technology of the micro-positioning platform which is driven by a voice coil motor. To improve the tracking accuracy and response speed, the sliding-mode active disturbance rejection control is proposed. The mathematical model of the micro-positioning platform control system is established, in which the perturbation and spring-damping force are set as the unknown terms, and an extended state observer is used to estimate and compensate for the unknown terms. To improve the robustness of the system, the equivalent sliding-mode term is constructed to replace the PD control term in the conventional active disturbance rejection. Further, the stability of the system is proved by the Lyapunov stability theory, and compared with the conventional sliding-mode controller, the effectiveness of the proposed control strategy is verified by simulation.