Experimental characterization, modeling and compensation of rate-independent hysteresis of voice coil motors

摘要

The hysteresis nonlinearities of a voice coil motor are characterized under different amplitudes and bias levels of input current signals. The measured data reveal that the asymmetric characteristics of the output input hysteresis loop are strongly dependent on the amplitude and bias of the input signal. A modified Prandtl-Ishlinskii model is proposed in this study to model the rate-independent hysteresis nonlinearities of a voice coil motor. The proposed hysteresis model is composed of a series of generalized operators and an input function based on Fermi-Dirac distribution. Comparisons of the model responses with the measured data under different amplitudes of input current signals indicate that the proposed model can effectively describe the rate-independent nonlinear hysteresis properties of the voice coil motor within the travel range of 4.3 mm. Subsequently, the inverse of the proposed Prandtl-Ishlinskii model is obtained analytically. The inverse model is utilized as a feedforward compensator to compensate the rate-independent hysteresis nonlinearities without using feedback control techniques. The compensation experiments are performed to verify the validity of the inverse model. (C) 2016 Elsevier B.V. All rights reserved.