A LPV/ℌ∞ fault tolerant control of vehicle roll dynamics under semi-active damper malfunction

This paper proposes a LPV/ℌ_∞ fault tolerant control strategy for roll dynamics handling under semi-active damper´s malfunction. Indeed, in case of damper´s malfunction, a lateral load transfer is generated, that amplifies the risks of vehicle roll over. In this study, the suspension systems efficiency is monitored through the lateral (or longitudinal) load transfer induced by a damper´s malfunction. The information given by the monitoring system is used in a partly fixed LPV/ℌ_∞ controller structure that allows to manage the distribution of the four dampers forces in order to handle the over load caused by one damper´s malfunction. The proposed LPV/ℌ_∞ controller then uses the 3 remaining healthy semi-active dampers in a real time reconfiguration. Moreover, the performances of the car vertical dynamics (roll, bounce) are adapted to the varying parameter given by the monitoring of the suspension system efficiency, which allows to modify online the damping properties (soft/hard) to limit the induced load transfer. Simulations are performed on a complex nonlinear full vehicle model, equipped by 4 magneto-rheological semi-active dampers. This vehicle undergoes critical driving situations, and only one damper is considered faulty at ones. The simulation results show the reliability and the robustness of the proposed solution.