Patent ID: 7849954
Filing Date: 2010-12-14
Classification: B62D

Abstract:
1. A steering system for a vehicle, comprising: a pair of operating members operable independently of each other so as to be movable along given orbits, respectively; a wheel turning device configured to turn a wheel of the vehicle; a pair of return-force applying devices each having a power source that is controllable to apply, to a corresponding one of said pair of operating members, a return force as a force for returning said corresponding one of said pair of operating members to a return-force reference operating position that is set for said corresponding one of said pair of operating members; a controlling device having (a) a wheel-turning control portion which is configured to determine a target wheel-turning amount of the wheel based on an amount of operation of each of said pair of operating members from a wheel-turning reference operating position that is set for said each of said pair of operating members and to control said wheel turning device for equalizing an actual wheel-turning amount of the wheel to the target wheel-turning amount of the wheel, and (b) a return-force control portion which is configured to determine the return force for returning each of said pair operating members, based on an amount of operation of said each of said pair of operating members from the return-force reference operating position that is set for said each of said pair of operating members and to control the power source of each of said pair of return-force applying devices for causing the power source so as to exhibit the return force; wherein said controlling device is capable of changing at least one of (A) a steering gain that is set for each of said pair of operating members upon determination of the target wheel-turning amount and (B) a return-force gain that is set for each of said pair of operating members upon determination of the return force, and wherein at least one of the steering gain and the return-force gain that are set for each of said pair of operating members is changed depending on an operating position of said each of said pair of operating members, and is changed depending on whether said each of said pair of operating members is positioned in one side region or another side region of a corresponding one of the given orbits, which are close to one and the other of opposite ends of the corresponding orbit, respectively, so that a value of each of said at least one of the steering gain and the return-force gain upon positioning of each of said operating members in the one side region of said corresponding orbit is different from a value of said each of said at least one of the steering gain and the return-force gain upon positioning of said each of said operating members in the other side region of said corresponding orbit.