Abstract
Integrated chassis control is a popular topic of research in the field of vehicle dynamics due to the ever-increasing number of active systems being fitted on modern vehicles. Furthermore, the advance of autonomous driving and V2X communication open new opportunities for control system design which model-based control systems are especially suitable for. Simultaneously, such systems, particularly model-predictive control (MPC), become increasingly more feasible for real-time implementation as the performance of computing hardware increases every year. Therefore, this doctorate thesis presents four studies on the topic of model-based integrated chassis control. The first chapter presents a literature survey into the applications of model predictive control for vehicle stability control on human-driven and autonomous vehicles, the trend to include multiple objectives in the optimisation cost function as well as showing the importance of modelling tyre nonlinearities in the prediction model. The second chapter presents a nonlinear MPC for traction control and anti-jerk control for electric vehicles with V2X connectivity and configured with a single motor and open differential. The V2X connectivity provides the controller with information of the friction conditions of the road ahead, allowing the controller to anticipate friction coefficient jumps and in experimental tests reduces the wheel slip tracking error compared to a non-pre-emptive version of the same controller. For high-performance vehicles, the integration between active aerodynamics, braking systems and electric motors is presented in the third chapter, with a focus on increasing energy recovery efficiency by the electric motors at high decelerations. Quasi-static optimisations and a feedforward integrated control algorithm based on them and applied and tested in simulation show that the solution to the optimal angle of attack is non-trivial. Finally, the fourth chapter presents two nonlinear MPC algorithms to further study the integration of the active aerodynamics with the rest of the vehicle dynamics control systems. In particular, the second nonlinear MPC operates as a single-level controller, which carries out the functions of the electronic brakeforce distribution, torque vectoring system and anti-lock braking system. Thus, a single-level controller handles the objectives of controlling wheel slip, yaw rate, maximising regenerative power and meeting the driver deceleration demand. This level of integration is particularly useful for a vehicle with a split rear wing, which is able to generate a significant amount of yaw moment at high speeds and enhances the yaw stabilisation performance of the controller when tacking an emergency obstacle avoidance while applying partial braking force.