A control method of a electric power assisted steering system and an electric power steering apparatus

摘要

PROBLEM TO BE SOLVED: To provide a controlling method for an electric type power steering device and the power steering device itself capable of senseing the end abutting situation even under the condition that a motor is out of rotation.;SOLUTION: The electric type power steering device suppresses the driving power supplied to the motor to below the specified value on the conditions that (1) the rotating angle of a rotating angle sensor remains out of change, (2) the steering torque is over 7 Nm, and (3) the period in which the above two are met simultaneously exceeds 200 mS (Yes in all of (1) thru (3)). Thereby, the torque generated by the motor is decreased, and a rack shaft is returned in the direction opposite the rack end by the reaction force of the tire as long as the situation is in end abutting, which causes the steering shaft to rotate, to result in rotation of the motor and the rotating angle sensor. That is, a decrease of the driving power allows detecting of an end abutting situation if the rotating angle is varying (Yes in (4)), and no change in the rotating angle allows detecting of a motor stopping condition originating from any other factor.;COPYRIGHT: (C)2003,JPO