Robust smith predictor for vehicle steering assist control

摘要

Road departure accidents account for approximately one fifth of all vehicle accidents and over one third of all fatalities in the U.S. This paper describes an effort to design lateral active safety systems to help drivers during normal driving conditions. The issue of driver interactions must be considered when designing such systems because both the driver and the controller have control over the vehicle lateral motion. The investigation of robustness to driver uncertainty in controller-design is presented. Previous research discussed a systematic method to compute the driver model and its uncertainty using a system identification approach (Chen and Ulsoy, 1999). The driver model and its uncertainty are used here to design a robust controller for the steering assist control system. Two robust control techniques, namely, H_infinity control and Quantitative Feedback Theory (QFT), are investigated. Due to time delay in the driver model, a robust Smith predictor scheme is employed to address the delay element. The two robust controllers, and the effectiveness of the Smith predictor scheme, are evaluated using frequency domain analysis and time domain simulation.