Interval observer design for switched systems with state and output uncertainties: Application to vehicle sideslip angle estimation

Abstract : This paper investigates the design of interval observer for switched uncertain systems with bounded uncertainties that appear in both the state and output equations. The proposed observer provides an envelope covering all possible state trajectories. By means of multiple ISS-Lyapunov function as well as linear matrix inequalities formulation, the interval observer gain matrices are determined and sufficient conditions ensuring the Input-to-State Stability (ISS) of the estimation error are proposed. An application for vehicle lateral dynamics estimation is presented to evaluate the performance of the proposed algorithm. The interval observer is applied to estimate the sideslip angle in the presence of uncertain tire cornering stiffness parameters and time-varying vehicle longitudinal velocity. The obtained observer is evaluated using experimental data acquired with a prototype vehicle. The simulation results demonstrate the validity of the proposed design.