MPC for vehicle lateral stability via differential braking and active front steering considering practical aspects

This paper presents a control architecture that simultaneously utilizes active front steering (AFS) and differential braking for vehicle lateral stability while minimizing longitudinal perturbations. This control scheme is based on the model predictive control (MPC) using the extended bicycle model that captures the lagged characteristics of tire forces and actuators. The nonlinearities of tire force are also reflected on the extended bicycle model by linearizing the tire forces at the operating points. Instead of casting the MPC problem into a quadratic program with constraints that require numerical solvers, the proposed method is designed to follow the reference states with desired inputs since the solutions of MPC problems with affine models to track desired states can be easily obtained by matrix inversion. Simulation results, obtained by the vehicle dynamics software Carsim, demonstrate that the suggested method is able to control the vehicle to track the desired path while keeping the vehicle lateral stability on various road surfaces.