Mirror Supporting Device Based on Magnetorheological Fluid and Control Strategy Based on Force Signal Feedback for Mirror Milling

A reasonable supporting device and effective supporting control strategy is the key to ensuring the stable progress of mirror milling. The complexity, nonlinearity, and external interference of the mirror milling process make it difficult to apply the traditional supporting device and its control algorithm. In this paper, a mirror supporting device based on magnetorheological fluid and its control strategy based on force signal feedback for mirror milling was proposed. The mirror supporting device integrates a force sensor, magnetorheological fluid, excitation coil, and rolling friction device into a reasonable supporting device to achieve stable support. A supporting force control algorithm with active disturbance rejection control (ADRC) as the outer ring, PID position control as the inner ring, and extreme learning machine (ELM) to compensate the uncertainty of mirror milling system. Combining the proposed supporting force control algorithm, flexible controllable supporting with “profile-fitting, stiffness-adjustable, and force-controllable” is realized. The supporting experiments and mirror milling experiments show that the designed supporting device based on magnetorheological fluid and the force feedback control algorithm can not only ensure the stability of the mirror milling process, ensure the machining accuracy, but also effectively avoid the supporting device on the workpiece surface scratch.