Analysis on Steering Gain and Vehicle Handling Performance with Variable Gear-ratio Steering System(VGS)

A change of vehicle handling characteristics due to increase of lateral acceleration as well as effects of the steering gain adaptation of VGS to that was analyzed by quasi-steady-state analysis to find out a basic strategy for the adaptive gain scheduling in the VGS. A study using a simple fixed base type of simulator showed the upper and lower limit of the appropriate gain of the steering system. A computer simulation study on lane-change response of the driver-vehicle-system gave us a view that there exists a suitable gain setting for the VGS from a view point of driver-vehicle-system stability.