【摘要】 针对电动助力转向(Electric power steering,EPS)系统存在系统模型、干扰等不确定性,以及对系统动态特性的要求,提出EPS系统混合H2/H∞控制器。在EPS系统及整车2自由度数学模型基础上,以驾驶员获得良好的转向路感、系统具有卓越的鲁棒性和较小的力矩波动为控制目标,构建系统的状态空间方程和增广被控对象矩阵,运用H∞方法极小化系统中各种干扰对被控输出的影响,并在此基础之上应用H2方法对系统进行优化。EPS系统路感仿真结果表明,基于混合H2/H∞控制的EPS系统,综合了H2控制和H∞控制的优点,具有较好的鲁棒性能和鲁棒稳定性,可有效抑制路面随机激励、转矩传感器量测、模型参数不确定等所引起的各种干扰和噪声,使驾驶员获得满意的路感。更多还原

【Abstract】 In view of the existence of uncertainties such as system model and disturbance signal in the electric power steering(EPS) system, and the demand for system dynamic performance, the mixed H2/H∞ controller is proposed.For the driver to obtain a good steering feeling and for the system to have good robustness and small torque fluctuation, the models of EPS system and the two-freedom car are set up, and the state space model and augmented matrixes are built.The H∞ method is introduced to minimize the effect of disturbances on outputs, and the H2 method is applied to optimizing the system performance.The simulation results of steering feeling show that the controller, which synthesizes the advantage of H2 control and H∞ control, has better robust performance and robust stability.The controller can attenuate the noises and disturbances caused by road random motivation, torque sensor measurement and model parameter uncertainty, and enable the driver to obtain a satisfactory road feeling.更多还原