| 摘要 |
PURPOSE:To make it possible to stop the rear wheel steering securely thereafter by short-circuiting the power source terminals of a motor for the rear wheel steering, when a disorder is detected in the motor control system. CONSTITUTION:When an abnormality signal is output from a microcomputer 21, a reset pulses Rs from the output terminal W2 of a watchdog timer 23 is input to the microcomputer 21 and a counter circuit 22. When the count value of the counter circuit 22 exceeds a set value, the logic output of an OR gate circuit 24 is made into '1', and transistors 28 and 29 are ON. As a result, a constantly closed type relay 31 is OFF, a constantly closed type relay 32 is ON, the driving power is not input to a motor 8 from a motor driving circuit 9, and the rotation of the motor 8 is stopped. At the same time, by closing the constantly closed type relay 32, the power source terminals of the motor 8 are short-circuited and the output shaft 8a of the motor 8 is fixed. Thereafter, the delivery of the steering force to the rear wheels 1 is stopped. |
