ELECTRIC POWER STEERING DEVICE

摘要

PURPOSE:To remove an adverse friction effect at the return of a steering wheel by determining an electric motor control signal for a power steering device with due consideration of the friction of a steering booster even at steering and return conditions. CONSTITUTION:An electric motor drive means 40 comprises a bridge circuit consisting of a drive unit 41 and FET 42-45. In the bridge circuit, each drain terminal of FET 42 and 45 is connected to A terminal of a power circuit, while the source terminals thereof are connected to the drain terminal of other FET 43 and 44. The gate terminal of FET is connected to the output side of the drive unit 41, and the source terminals of FET 42 and 45 are connected to an electric motor. The drive unit 41 makes FET 42 and 44 operable on the basis of a control signal for electric motor rotating directions as received from a micro computer 30, and drives FET according to a signal T4 for electric motor control.