Study on digital control system of AC 2-degree freedom HMB based on parameter automatic self-adjustment fuzzy PID

In this paper, an AC 2-degree freedom hybrid magnetic bearing (HMB) is proposed, which is driven by a 3-phase AC power inverter. The configuration and the operating principle producing magnetic suspension forces of the AC 2-degree freedom HMB are introduced. By using equivalent magnetic circuit method, the calculation formulas of magnetic suspension forces and the mathematics models of the system are deduced. The parameter automatic self-adjustment fuzzy PID control algorithm of the AC 2-degree freedom HMB is researched. The parameter automatic self-adjustment fuzzy control rule is designed. The simulation experiment of the parameter automatic self-adjustment fuzzy PID control algorithm of the AC 2-degree freedom HMB has been done. The simulation experiment result has shown that the parameter automatic self-adjustment fuzzy PID control algorithm of the AC 2-degree freedom HMB has the control performance of small overshoot, fast response, good stability and strong disturbance rejection ability. Then based on the mathematics models of the AC 2-degree freedom HMB, a digital control system of this novel bearing is designed based on parameter automatic self-adjustment fuzzy PID and TMS320F2812 DSP. The performances of the digital control system of the AC 2-degree freedom HMB has been test by experiment. The experiment result has shown that the control performance of the digital control system of the AC 2-degree freedom HMB based on parameter automatic self-adjustment fuzzy PID is well. This innovated AC 2-degree freedom HMB can be applied in high speed machine tool spindle with lower manufacturing and operation costs.