Vehicle On-Center Directional and Steering Sensitivity 2005-01-0395

Steering activity in response to deviations from the intended straight-ahead vehicle path is an important factor of vehicle-driver on-center performance. Traditionally, setting the parameters of vehicle models for stability analysis does not involve vehicle properties that make the vehicle deviate from its intended path with no steering input. However, for closed loop simulations where driver steering activity is considered a fundamental human performance measure, the ability of the vehicle model to faithfully generate path deviations in response to external forces is required for steering performance measures fidelity. Path deviations cause the driver to make small steering angle corrections to keep the vehicle on its intended straight path. It is in fact a natural driving load that should be included in every closed loop simulation before considering any study involving driving loads and driver distractions. This paper explains the physics of these small deviations and proposes a model that mimics path deviations seen on the road. A comparison is made between vehicle road data measurements and simulation results.