An integrated control of front/rear traction distribution and differential braking for limit handling

Abstract

The paper proposes methods for the analysis and the control design of variablegeometry suspension systems. The tilting actuation of the front wheel improves the lateral dynamics of the vehicle and assists the driver in avoiding critical situations. The novelty of the method is the consideration of the nonlinearities in the tyre characteristics. The nonlinear polynomial Sum-of-Squares (SOS) programming method is applied in the analysis and it gives the optimal utilization of the maximum control forces on the tires. Moreover, the construction of the system can be based on the nonlinear analysis. An LPV (Linear Parameter-Varying) based control-oriented modeling and control design for lateral vehicle dynamics are also proposed, which guarantee the trajectory tracking of the vehicle. The simulation example presents the efficiency of the variable-geometry suspension system and it shows that the system is suitable to be used as a driver assistance system.