Optimizing Variable Ratio Steering for Improved On-Centre Sensitivity and Cornering Control

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.