Designing Steering Feel for Steer-by-Wire Vehicles Using Objective Measures

Drivers use torque feedback at the handwheel of a vehicle, or steering feel, to obtain information about the road and tire dynamics. This aids them in driving tasks like curve negotiation. Steer-by-wire vehicles, due to the mechanical decoupling of the front tires and handwheel, do not have any inherent steering feedback and require an artificial steering feel. One way to implement an artificial steering feel is to synthesize steering feedback with a model running on board the vehicle. Identifying the appropriate level of model fidelity required involves understanding what elements of steering feel are important. This paper proposes using objective steering feel measures used in industry as a means of understanding which elements of steering feel are most important. It also introduces a steering feel model of appropriate fidelity to capture these important elements of steering feel while remaining intuitive to tune objectively with a small set of parameters. Experimental data show that the desired performance measures obtained via dynamic vehicle simulation can be replicated on an actual steer-by-wire vehicle, validating the design technique.