Abstract: It is an object to provide an electric power steering apparatus capable of preventing torque steer or deflection during braking, a control method thereof and a program for the electric power steering apparatus. An electric power steering apparatus controlling a steering assist motor 20 based on a steering assist command value I calculated based on steering torque T occurring to a steering system of a vehicle and a vehicle speed V, and a current detection value Im of the steering assist motor 20 which gives a steering assist force to the steering system, wherein a compensation control section 70 conducts compensation control that compensates steering characteristics of the steering system by compensating the steering assist command value I, and changes a compensation amount of the compensation control based on longitudinal acceleration ?x of the vehicle.

Abstract: A computed SAT value SATa is computed, and an estimated SAT value SATb is estimated from lateral force. A grip loss level “g” is computed from difference between the computed self aligning torque value SATA and the estimated SAT value SATb. Torque correction value ?T which becomes greater with an increase in grip loss level “g” and an increase in angular speed ? is set in accordance with the grip loss level “g” and the angular speed ? of an electric motor 12 serving as corresponding steering angular speed. The corresponding torque correction value ?T is subtracted from the current command value Itv responsive to the steering torque T and the vehicle speed V, thereby correcting the current command value Itv. The thus-corrected current command value Itv is taken as a steering assist command value Im, and the electric motor 12 is driven based on the steering assist command value.