Research into the optimization of a Variable Ratio (VR) steering characteristic for rack and pinion steering gears was conducted. The VR steering characteristic was refined in a passenger car to achieve the optimum steering control for cornering and emergency maneuvers, whilst retaining the required on-centre performance needed for high-speed controllability.
The research showed that the best steering performance resulted from high steering ratios on-centre, which rapidly reduce to lower ratios off-centre. This VR steering characteristic should result in vehicles with improved predictability of yaw and lateral acceleration response, whilst maintaining ease of on-centre control. This will reduce the skill level required in straight line running and maintaining control in emergency maneuvers.
Tajima, J., Yuhara, N., Sano, S., Takimoto, S., “Effects of Steering System Characteristics on Control Performance from the Viewpoint of Steer-by-Wire System Design,” SAE Paper No. 1999-01-0821, Society of Automotive Engineers, Warrendale, PA, 1999
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See papers presented at SAE 2000 World Congress, March 2000, Detroit, MI, USA, Session: Steering & Suspension Technology Symposium - Steering Technology (Part C&D)
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