基于离散逆Preisach模型的磁悬浮系统非线性补偿研究

Research on Nonlinear Compensation of Magnetic Levitation System Based on Discrete Inverse Preisach Model

磁悬浮平台控制中,电磁铁铁芯材料的磁滞特性会很大程度影响控制精度,补偿磁滞特性是磁悬浮精密控制系统中必不可少的一部分,为了实现对磁悬浮精密控制系统中磁滞非线性的补偿,课题组使用离散逆Preisach模型构造了一个补偿器。首先建立了离散逆Preisach模型,再依据磁滞补偿原理,构造补偿器;根据逆模型的曲线形状,建立了基于双曲正切的分布函数验证离散逆Preisach模型构造的合理性;最后使用非负最小二乘法辨识模型。结果表明离散逆Preisasch模型描述电磁铁逆磁滞回线的最大误差为0.3%。所构造的补偿器具有良好的补偿效果,为磁悬浮系统的磁滞补偿提供了一种可行方案。

In the control of the magnetic levitation platform,the hysteresis characteristics of the electromagnet core material will greatly affect the control accuracy,and the hysteresis characteristics of compensating are an indispensable part of the magnetic levitation precision control system.In order to realize the compensation of hysteresis nonlinearity in the magnetic levitation precision control system,a discrete inverse Preisach model was used to construct a compensator.Firstly,the discrete inverse Preisach model was established,and then the compensator was constructed according to the hysteresis compensation principle.According to the curve shape of the inverse model,a distribution function based on hyperbolic tangent was established to verify the rationality of the discrete inverse Preisach model.Finally,the non-negative least squares identification model was used to identify the model.The results show that the maximum error of inverse Preisasch model in describing the electromagnet inverse hysteresis loop is 0.3%.The constructed compensator constructed has good compensation effect and provides a feasible scheme for hysteresis compensation of magnetic levitation system.