Torque-Vectoring-Based Vehicle Control Robust to Driver Uncertainties

Driver-in-the-loop stability is a central issue in vehicle control systems. However, since a general human behavior model to explore it in a quantitative fashion has been lacking, little is known about how the vehicle can be controlled while considering the driver effects. Indeed, applying a control method without considering the driver effects, and instead separating human level and machine dynamic layers, guaranteeing stability of a vehicle, is impossible. Here, a new formulation of the problem that involves a driver model and a linear vehicle model is proposed. Given that practical controllers usually do not have access to the future road preview data, this information is also modeled in terms of bounded uncertainties. The design allows the tools of robust control to stabilize the system, offering an implementable approach to overcome ranges of delay and uncertainties of closed-loop modeling due to the human presence. The formulation can further deepen the understanding of the effects of a driver during vehicle steering. To evaluate the proposed controller, a nonlinear full vehicle model along with a driver model in CarSim are used. The simulations performed for a standard harsh double-lane-change scenario under different driver and vehicle conditions demonstrate that vehicle stability is enhanced using the proposed controller.