The LPV approach: the key to controlling vehicle dynamics ?
Résumé
This plenary talk aims at presenting the interest of Linear Parameter Varying (LPV) methods for vehicle dynamics control. While the use of this approach to deal with non linear systems is now well established, it will be shown, further, to be flexible and robust enough to handle several types of constraints and objectives such as: actuator non linearities, real-time varying performances, control allocation and coordination for MIMO systems, fault tolerant control w.r.t sensor/actuator failures...In the first part, we will consider the semi-active suspension control problem, for which the challenge is the ability of taking into account the dissipativity of the damper (and eventually some loss of efficiency) in the control design step. Different LPV models of semi-active dampers will be presented, allowing to take into account some non linearities (hysteresis, dissipativity, ...) and damper faults. Then LPV control methodologies will be described, where the parameters can take the real abilities of the damper into account.In the second part the synthesis of an LPV / $H_\infty$ MIMO vehicle dynamic controller, involving suspension, steering and braking actuators, is proposed to improve the vertical and lateral performances through a gain-scheduling of the $3$ control actions according to the driving situation evaluated by a specific monitor. An original LPV method for actuator coordination is proposed, when the actuator limitations and eventually failures, are taken into account.Simulation results using vehicle models validated on a real car, will show the efficiency and robustness of the proposed solutions.