关键词: 电动助力转向系统, 混合H2/H∞控制, 路感

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.

Key words: Electric power steering system, Mixed H2/H∞ control, Road feeling