ELECTRICAL CONTROL UNIT FOR REAR WHEEL STEERING SYSTEM

摘要

PURPOSE:To prevent the temporary marked lowering of battery voltage by limiting the grade of a driving current flowing to a drive motor for the steering of rear wheels in the lowered state of battery voltage in a rear wheel steering system for steering rear wheels by the rotation of the drive motor. CONSTITUTION:When the voltage of a battery 40 is lowered, a microcomputer 36 sets the duty ratio of a driving current smaller than the normal case in response to the battery voltage detected by a voltage detector 35 and outputs a control signal indicating this duty ratio to a driving circuit 37. According to this duty ratio, the driving circuit 37 controls the driving current to be supplied to a drive motor 21. Accordingly, in the case of the voltage of the battery 40 being lowered, the driving current flowing to the drive motor 21 through the driving circuit 37 from the battery 40 is limited to avoid the marked voltage lowering of the battery 40.