主动转向系统鲁棒控制的研究

A Study on the Robust Control of Active Steering System

本文中建立了引入主动转向系统模型,并考虑了参数不确定性的2自由度非线性整车模型。以上述模型作为被控对象,以一阶传递函数作为理想参考模型,运用标准H∞、环路成形和μ综合等方法分别设计了3种2自由度鲁棒控制器,并对其特性进行了频响分析和μ分析。对非线性整车模型进行了仿真。结果表明,各鲁棒控制器对抑制侧向力、横摆力矩和传感器量测的干扰、减小转向系统对整车动力学特性的影响以及提高驾驶稳定性和主动安全性等方面具有明显的效果,且均具有各自的优势特点,其中,μ综合控制器具有较低保守性和良好鲁棒性能。

In this paper, a 2-DOF nonlinear vehicle model is set up, which incorporates an active steering system model and with consideration of parameter uncertainty. With the model as control object and the 1 st order transfer function as reference, the standard H∞, loop-shaping and μ synthesis methods are used respectively to design three types of 2 DOF robust controllers with frequency response analysis and μ analysis conducted on their characteristics. A simulation on nonlinear vehicle model is then performed. The results show that all three robust con- trollers have apparent effects in suppressing the interferences of lateral force, yaw moment and sensor measurement, weakening the effects of steering system on vehicle dynamic characteristics and enhancing driving stability and active safety, and each of them has its own distinct feature, in which μ synthesis controller is less conservative with good robustness.