Steering gear ratios in existing automobiles are made almost constant. Therefore, at low speed, the larger steering wheel angle needed increases drivers' physical workload especially in the case of a maneuver with large directional angle change such as parking, and may impair quickness in response necessary for a sudden lane change maneuver such as obstacle avoidance at low speed.On the contrary, at high speed, a relatively small steering angle input can generate comparatively large vehicle lateral acceleration, and this larger overall steering gain may necessitate drivers' more meticulous steering operation which can produce increased mental workload.In addition, for understeer vehicle, steering gain tends to decrease as lateral acceleration increases because of saturation in lateral force of the tire, and this may also reduce maneuverability in directional change, especially during cornering.In order to address these possible factors, a steering system in which the equivalent steering gear ratio increases (becomes lower geared) with the increase of vehicle speed, and decreases ( becomes higher geared ) with the increase of steering wheel angle was created, and its effects on driver-vehicle response and performance were studied.This paper presents the selection of variable characteristics of steering gear ratio derived from observations of drivers' steering behavior and from the results of proving ground tests, and describes the mechanism of a steering gearbox which could realize the proposed steering characteristics, and the construction of such a steering system. The results of simulations and proving ground tests, which indicate improvement in performance as expected, are shown as well.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Improvement in Driver-Vehicle System Performance by Varying Steering Gain with Vehicle Speed and Steering Angle: VGS (Variable Gear-Ratio Steering System)


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    International Congress & Exposition ; 1999



    Publication date :

    1999-03-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English






    Analysis on steering gain and vehicle handling performance with variable gear-ratio steering system ( VGS )

    Abe,M. / Shibahata,Y. / Shimizu,Y. et al. | Automotive engineering | 2000


    Vehicle steering gear, steering system and vehicle

    XU NA / ZOU JUN / JIN ZHAOJIANG et al. | European Patent Office | 2021

    Free access

    STEERING GEAR OF VEHICLE WITH VARIABLE GEAR RATIO

    SVECHNIKOV DMITRIJ ANATOLEVICH / PASHAEV OLEG FIRIDINOVICH | European Patent Office | 2020

    Free access