Fuzzy control of voice coil motors with peak compensation for high-frequency composite motion under variable load

A linear voice coil motor (VCM) boasts advantages such as high motion precision, high linearity, and fast dynamic response, making it a key driving device in fast tool servo systems within the field of precision machining. However, when VCMs perform high-frequency reciprocating motions under the control of the classical PID method, they struggle to autonomously adapt to changes in motion conditions and load conditions, leading to a decline in displacement accuracy. Therefore, this paper proposes an adaptive control method based on fuzzy inference and peak compensation strategy, which can identify working conditions according to the peak changes of the displacement curve and achieve precise compensation of control parameters, thereby ensuring high-precision displacement of the VCM. In this paper, PD control and adaptive PD control for the position loop are used as comparative control methods. The experimental results show that the motion precision of the VCM under the proposed method is significantly higher than that under the other two methods. Under the toughest condition of a load mass of 250 g, in a sinusoidal motion with an amplitude of 0.2 mm and a frequency of 60 Hz, the absolute peak error under the proposed method reaches approximately 1.2 μm. Across different experimental conditions in this research, the relative peak errors under the proposed method all remain below 3%.