Position regulator for spindle of milling machine by embedded magnetic bearings

The goal of this work is to concurrently counterbalance the dynamic cutting force and regulate the spindle position deviation by integrating active magnetic bearing (AMB) technique, fuzzy logic algorithm and an adaptive self-tuning feedback loop. Themathematic model for cutting dynamics is constructed by experiments so that the system parameters can be on-line estimated by employing the proposed fuzzy logic algorithm. Once the cutting force can be real-time estimated, the corresponding compensation force can be exerted by the equipped AMB to counter-balance the cutting force (i.e., via inner-loop), in addition to the spindle position regulation by the feedback of spindle position (i.e., via outer-loop). At the end, the experimental simulations on realistic milling are presented to verify the efficacy of the fuzzy controller for spindle position regulation and the capability of the dynamic cutting force counterbalance.