The Virtual Wheel Concept for Supportive Steering Feedback During Active Steering Interventions

Active steering systems allow for improved vehicle safety and stability through steering interventions that augment a driver’s steering command. In a conventional steering system, steering feedback torque depends on the tire forces and corresponding moments that act on the roadwheels. During active steering interventions, there are differences between the driver’s command and the actual roadwheel angle. The steering feedback can now be based on either the moments acting on the actual roadwheels or the moments acting on a virtual wheel following the driver’s intended steering command. With small interventions, the difference between these two approaches is negligible. However, when the intervention is large (e.g. obstacle avoidance maneuvers), basing handwheel moments on the actual roadwheel position results in a handwheel torque that acts in opposition to the intervention. The virtual wheel concept produces a more supportive, and potentially more intuitive, handwheel torque. This reduces the discrepancy between the driver command and the active steering system in simulation and experiments.