Nonlinear Model Predictive Control for Path Tracking in High-Speed Corner Entry Situations

Path tracking control is one of the essential controls for lateral positioning controls such as collision avoidance and lane keeping and changing. In severe situations in which the tire force reaches its limit, such as entering a corner at high speed or in a low-friction situation, not only accurate path tracking but also stable driving must be ensured. In this paper, an integrated braking and steering controller for path tracking is proposed in consideration of the road friction limit. In particular, individual tire forces were predicted using the vehicle and the tire models, and the results were directly compared with the road friction. A nonlinear model predictive controller (NMPC) was utilized for constrained optimal control using nonlinear models. The proposed controller is verified through vehicle simulators Carsim and MATLAB Simulink. Results show the effectiveness of the proposed controller: it guarantees stable driving and accurate tracking performance.