基于无刷直流电机EPS H_∞控制的研究

Research on BLDC Motor Strategy for Electric Power Steering System with H_∞ Robust Control

为验证鲁棒控制理论是否适用于无刷直流电机控制的EPS系统,本文针对EPS系统非线性多输入多输出的系统特点,在应用无刷直流电机的基础上,采用H∞控制方法设计其控制器。首先根据EPS系统动力学模型,进行不确定性分析;然后建立EPS系统的状态空间方程和增广被控对象矩阵,将其描述成标准H∞问题求解;利用H∞方法极小化系统中各种干扰对被控输出的不确定性影响。计算机运算结果表明:应用鲁棒控制理论所设计的EPS控制器有良好的鲁棒性能。

To verify the adaptation of robust control theory on the EPS system controller design which is based on BLDC motor,aimed at the nonlinear MIMO electric power steering system and on the basis of BLDC,the H∞ robust control method is employed to design controller in this paper. At first,according to the kinetic model of the EPS,the uncertainty analysis is introduced. Further more,in order to consider the factor of disturbances,the state space formulation and the extended controlled object matrix are determined. Finally,the H∞ method is introduced to minimize the effect of disturbances on outputs. The calculation results show that the controller can improve the performance of EPS and its robustness.