CONTROLLER FOR ELECTRIC POWER STEERING DEVICE

摘要

A controller for an electric power steering device causes, independent of a road surface condition, to produce most suitable torque steer-reducing torque corresponding to actual torque steer without causing unnecessary torque steer-reducing torque to be produced. Basic assist torque (Tab) is calculated (S20-40) based on steering torque (Ts) and a vehicle speed (V), toque steer-reducing torque (Tats) is calculated (S50-100) based on a brake pressure difference (DeltaP) between left and right wheels and deceleration (Gbx) of a vehicle such that the greater the brake pressure difference (DeltaP) and the higher the deceleration (Gbx), the greater the torque steer-reducing torque (Tats), and assist torque is controlled (S110, 120) based on the sum of the basis assist torque (Tab) and the torque steer-reducing torque (Tats). When the magnitude of the brake pressure difference (DeltaP) between the left and right wheels is equal to or less than a standard value (DeltaP0), the torque steer-reducing torque (Tats) is set to 0 (S70, 80, 100) when the deceleration (Gbx) of the vehicle is equal to or less than a lower limit standard value (Gbx1) or equal to or more than an upper limit standard value (Gbx2).