为了主动磁力轴承分析和控制的需要,提出一种建立其非线性的力一电流—位移关系逆T-S模糊模型方案。该模糊模型的输入为电磁力和转子位移,输出为控制电流。该方案将模糊聚类分析、最小二乘法和残差分析有机结合,采用模糊聚类分析方法确定前提结构和参数,采用最小二乘法确定结论参数,并通过对残差的分析进一步确定模糊规则的数目。使用所提方法对一单自由度磁力轴承进行建模。为使磁悬浮转子在离平衡位置的大位移范围运行,采用了具有一定幅值的低频正弦信号作为参考输入信号。仿真结果表明所获得的逆T-S模糊模型有很高的拟合精度。
A method of establishing the inverse T-S fuzzy model of the non-linear force-current-displacement relation is proposed for meeting the demand of active magnetic beating systems' analysis and control. In the inverse T-S model, the electromagnetic force and the rotor's displacement are defmed as input parameters, and the control current is defined as the output parameter. This method combines fuzzy cluster analysis, least square method, and remnant error analysis effectively. Fuzzy cluster analysis method is used to determine the premise structure and parameters. Least square method is employed to determine the consequence parameters. At last the amount of fuzzy rules is further determined by using remnant error analysis. A single-axis active magnetic bearing is modeled by using the proposed method. The simulation results demonstrate that the inverse model can reach very high fitting-precision.