doc. Ing. Martin Klaučo, MSc., Ph.D.

Integrated automated safety systems in vehicles significantly reduced the number of car crashes. They help the driver in critical maneuvers when tires lose their grip on the driving surface. For instance, the technology of the anti-lock braking system and its augmentations (electronic stability control and traction control system) has already saved thousands of lives. Nevertheless, we still see room for improvement. This work defines boundaries in the vehicle state-space, excluding unstable vehicle maneuvers. Such boundaries form a so-called driving envelope. The resulting set includes all states where the vehicle’s wheels are not locked, overspun, or skidding. For the definition of the driving envelope, we use the Pacejka tire model and nonlinear single-track model. This paper shows how each tire dynamic property results in vehicle dynamics. Also, it discusses the application of nonlinear and linearized driving envelope boundaries on a single-track model. Then it shows that the linearized driving envelope constraints form a close to control invariant set over the vehicle state-space. Thus, the driving envelope is almost a feasible set, and it could be used in the model predictive control approaches with soft constraints. Protecting the driving envelope, one can preserve each wheel from locking, wheelspin, and skidding.

Drive-by-wire technology opens a possibility to help the driver to drive a vehicle safely with support made by electronic control units. This paper presents an approach for defining a Driving Envelope that excludes any not welldefined vehicle states both for longitudinal and lateral dynamics. The second contribution is the design of a Model Predictive Controller for envelope protection that prevents critical situations such as the spinning of the vehicle, blocking of a wheel, and loss of the wheel traction. Validation results demonstrating the performance of the approach are obtained from a fixedsimulator with implemented high-fidelity twin-track model.

This paper presents an approach of utilizing Driving Envelope (DE) restrictions to assist the driver in lateral maneuvers. Two fundamental issues are addressed in this work. First, DE protection. Second, how to implement such functionality on a conventional car configuration, where the driver still needs to be a part of the control loop. The proposed functionality is based on a Model Predictive Controller (MPC). Vehicle states are constrained to avoid car critical spin situations (DE protection). The power-assisted steering system is used to guide the driver inside boundaries defined by the DE. The proposed architecture is compared with the standard car, without such an Advanced Driver-Assistance System (ADAS), by means of virtual ride tests performed using a high-fidelity vehicle model.

Automotive platooning can significantly improve traffic safety and efficiency, but many control challenges need to be solved to function properly under realistic driving conditions. This paper proposes a novel multi-rate explicit model-predictive controller (eMPC) for safe autonomous distributed vehicle platooning in varying road friction conditions. A safety-augmented distributed predictive control formulation ensures safe vehicle spacing versus emergency braking of preceding vehicles given current friction estimates. This complex control problem is carefully formulated into an efficiently parametrized optimization problem realized as eMPC. The resulting platoon shows excellent performance in a complex vehicle dynamics co-simulation validation with low communication and computation demands.