Handling Enhancement Due to an Automotive Variable Ratio Electric Power Steering System Using Model Reference Robust Tracking Control 960931
An automotive steering system that can vary the overall steering ratio as a function of the vehicle's forward speed has the potential to enhance the lateral handling qualities of the vehicle for different driving situations. A “quicker” steering ratio at low speeds can help provide greater ease in maneuvering the automobile. A “slower” steering ratio at higher speeds can alleviate the “dartiness” experienced by some vehicles with a fixed overall steering ratio. The concept of a vehicle's “sensitivity” to steering inputs from the driver is exploited to provide the basis for developing how the overall steering ratio is customized as a function of vehicle speed.
This paper compares the on-center handling performance of an automotive power steering system that is capable of varying the overall steering ratio versus vehicle speed against that of a traditional manual steering system with a fixed overall steering ratio. Dynamic simulation results demonstrate that the variable ratio steering system is capable of improving the on-center handling performance of the vehicle based on industry standard performance measurements.
Citation: Millsap, S. and Law, E., "Handling Enhancement Due to an Automotive Variable Ratio Electric Power Steering System Using Model Reference Robust Tracking Control," SAE Technical Paper 960931, 1996, https://doi.org/10.4271/960931. Download Citation
Scott A. Millsap, E. Harry Law
International Congress & Exposition
Suspensions and Steering Technology-SP-1136, SAE 1996 Transactions - Journal of Passenger Cars-V105-6