LQG理论的电动助力转向系统最优控制

通过建立电动助力转向系统的数学模型和计入随机干扰的受控系统状态空间表达式，应用极小值原理设计了线性二次型高斯状态反馈控制器，并基于最优估计理论设计了离散型Kalman滤波器。最后进行了仿真分析，其结果表明采用这种最优控制方法能有效地抑制路面随机激励、转矩传感器的量测噪声、模型参数不确定所引起的干扰以及减少转向盘的振动，使驾驶员获得较满意的路感，设计的最优控制器使闭环系统有较强的鲁棒性，提高汽车的操纵性能。

Study on Optimal Control for Electric Power Steering System Based on LQG Theory

The mathematical models of the electric power steering system were formed theoretically, and the state-space expression of the stochastic dynamic system was performed first. Then the LQG state feedback controller was designed with the minimum, and a discrete Kalman filter was proposed based on the optimal estimation theory. Finally, the simulation results showed that this optimal control method could attenuate the random road excitation, torque sensor measurement noises, model errors and disturbances reduce oscillations that might occur in the steering column, provide satisfied road feeling for drivers, the controller improves the robust performance of EPS system and enhances maneuverability of the vehicle.