Steering Actuator Efficiency Estimation for Vehicle Lateral Dynamics

This paper investigates observer design for actuator efficiency faults estimation for autonomous vehicles. We are focusing on the steering actuator efficiency. The vehicle lateral model is transformed into an uncertain discrete time LPV switched system. In fact the vehicle is subject to both measured varying parameters such as forward speed and unmeasured parameters such as tire cornering stiffness. The observer is designed in order to estimate both the vehicle state vector and the actuator efficiency gathered into an augmented state vector. The designed observer is able to estimate both constant and time varying actuator deficiency with bounded estimation error, while minimizing the effect of the input disturbance on the estimation error. The synthesis procedure is solved using linear matrix inequalities. Simulation results are provided and well illustrate the effectiveness of the proposed approach.