Abstract: This paper describes the application of electric power steering (EPS) system in new energy vehicles, and discusses the implementation of lane keeping assist (LKA) System in the automatic driving system of new energy vehicles. Firstly, a model is established for a brand of electric passenger car EPS, and a conventional assist control mode based on upper-level linear assist control and lower-level fuzzy proportion integral differentia (PID) control is developed; then, a two degree-of-freedom vehicle model and a vehicle-road error model are established, and a control strategy based on linear quadratic regulator (LQR) is developed, which is based on the vehicle state. The LKA is interacted with the EPS through the angle to realize the active front wheel turn control of the vehicle. Finally, MATLAB/Simulink and CarSim joint simulation platform is used for simulation and validation. The simulation results show that the developed control strategy can accurately realize the function of conventional power assist and LKA active steering of new energy vehicles, which can greatly improve the driving safety of vehicles.

Key words: EPS; LKA; Conventional power; Active steering; Optimal control; Joint simulation

摘要： 文章阐述了电动助力转向（EPS）系统在新能源汽车上的应用，探讨了新能源汽车自动 驾驶系统中的车道保持辅助系统（LKA）实现途径。首先，针对某品牌电动乘用车 EPS 建立 了模型，制定了基于上层直线助力控制和下层模糊比例-积分-微分（PID）控制的常规助力控 制模式；然后，建立二自由度车辆模型和车路误差模型，制定基于线性二次调节器（LQR） 的控制策略，根据车辆状态通过角度将 LKA 与 EPS 进行交互，实现车辆的主动前轮转向控 制。最后，利用 MATLAB/Simulink 与 CarSim 联合仿真平台进行仿真模拟验证，仿真结果显 示，制定的控制策略能够精确地实现新能源汽车的常规助力和 LKA 主动转向的功能，可极大 提高车辆的行驶安全性。

关键词: EPS；LKA；常规助力；主动转向；最优控制；联合仿真