Path Tracking Control Method with Steering Lag for Autonomous Vehicles

The automatic driving path tracking system is an important supporting technology for realizing automatic driving above L2 level. The delayed response characteristic of the linear steering system reduces the robustness and control accuracy of the path-tracking controller, with even instability at high speed. For the above problems, an error tracking control architecture with feedforward plus finite time domain full state feedback is designed in this paper, on the basis of which the steering system delay is modeled as a first-order inertial link and integrated into the error tracking control architecture as a state variable augmentation. In this paper, the proposed tracking controllers are compared and validated using joint simulation tests, and the validation results show that the maximum lateral error of the proposed controllers is less than 0.3 m in the right-angle corner and high-speed lane change scenarios, and the steering wheel's rotational angle rms variance is reduced by 1.93% and 64.22%, respectively. The final results of the real-vehicle tests show that the controller proposed in this paper can effectively improve the lateral control accuracy in the high-speed lane-changing scenario, with the maximum lateral error less than 0.11 m. © 2023 SAE-China. All rights reserved.