Simultaneous Estimation of Vehicle Lateral Dynamics and Driver Torque using LPV Unknown Input Observer

摘要

This paper presents a new method to estimate simultaneously both the vehicle state and the driver torque. To take into account the time-varying nature of the longitudinal speed, the vehicle system is transformed into a polytopic LPV model with a reasonable level of numerical complexity. The design of the LPV unknown input observer is reformulated as an LMI-based optimization which can be effectively solved via semi-definite programming. Based on Lyapunov arguments, the closed-loop of the state error dynamics is proved to be input-to-state stable while achieving a guaranteed L∞-gain performance. Numerical experiments obtained with a nonlinear vehicle system are provided to demonstrate the effectiveness of the proposed observer design.