STEERING FORCE CONTROL DEVICE

PROBLEM TO BE SOLVED: To improve rough-road traversability and stability of a vehicle by adding appropriate steering assisting force so as to offset steering reaction force during starting up or accelerating under conditions where the attitude of the vehicle becomes unstable.SOLUTION: When the vehicle is under specific driving conditions under which the attitude of the vehicle 1 becomes unstable, additional torque which is steering assisting force is added in a direction for stabilizing the attitude of the vehicle by electric power steering to perform attitude stabilizing control. The steering assisting force at the time is determined by calculation by proportional control and integration control of a steering torque sensor value and basic assisting torque of the electric power steering in relation to steering reaction force acting from a vehicle body side when a " steering wheel pulling phenomenon" occurs, and steering torque to make the steering torque sensor value zero is applied as additional torque of the electric power steering. An upper limit value of the additional torque is regulated based on restraining torque of an LSD (Limited Slip Differential Gear). By limiting the additional torque, a change of the steering reaction force accompanying an operation of the LSD is suppressed.