Citation

Liu YH, Ji XW. Proc. Inst. Mech. Eng. Pt. D J. Automobile Eng. 2011; 225(11): 1481-1491.

Copyright

(Copyright © 2011, Institution of Mechanical Engineers, Publisher SAGE Publishing)

DOI

10.1177/0954407011408370

PMID

unavailable

Abstract

Matching the assistant characters of an electric power steering (EPS) system so that the vehicle achieves a high performance is one of the key technologies in EPS design. A study on the matching strategy of EPS assistant characters is conducive to obtaining a good 'vehicle performance' earlier in the design process. This paper describes a method for designing the assistant characters of an EPS system based on the vehicle's inherent 'road feel' denoted here as the steering torque gradient at a 0g or 0.1g lateral acceleration under the condition that the steering system is not a power-assisted system. With the aim of obtaining the vehicle's inherent road feel, the relations between the steering resistant torque and the vehicle's travel states are analysed on the basis of a two-wheel vehicle model with a uniform normal tyre force distribution in steady state circle cornering. It is found that the vehicle's inherent road feel decreases with increasing speed especially in the low-speed regions. The matching strategy of EPS assistant characters based on the vehicle's inherent road feel is presented and illustrated by designing the assistant characters of a sample EPS system utilized in a passenger car. It is found that the EPS system designed by this strategy can supply a good steering feel to the driver.

Language: en