基于操纵稳定性的EPS转向系统鲁棒控制策略研究

Robust control strategy for electric power steering system based on handling stability

针对电动助力转向(EPS)系统存在传感器噪声、路面干扰、参数摄动等不确定性,以及对系统动态特性的要求,设计一种基于操纵稳定性的电流H∞鲁棒控制器。分别建立EPS转向系统及简化的二自由度整车动力学模型,以驾驶员路感良好、汽车操纵稳定性强及EPS系统鲁棒性优越为控制目标,构建系统的状态空间方程和被控对象增广模型,并对EPS控制系统进行仿真。结果表明,所设计H∞鲁棒控制器不仅能够保证满意的路感、良好的操纵稳定性,而且可以有效抑制传感器噪声和路面干扰的影响,从而提高EPS系统的稳定鲁棒性。

In view of the sensor noise ,road disturbance and uncertainties such as parameter change in the electric power steering （EPS） system and the demand for system dynamic performance ,a current controller of EPS system was designed using H ∞ robust control method based on vehicle handling sta-bility .For good steering feeling of the driver ,improved vehicle handling stability and excellent ro-bustness of the system ,the dynamic models of EPS system and the simplified two-freedom vehicle were constructed ,and the state space model and the controlled object augmented model were also built .The simulation results indicate that the designed control system for EPS can ensure satisfactory road feel and excellent handling performance and it can also effectively restrain sensor noise and dis-turbances caused by system uncertainties and road conditions ,thus raising the robustness of the EPS system .