| 摘要 |
PURPOSE:To prevent the occurrence of abnormal rear wheel control by detecting the failure of a vehicle speed sensor on the basis of a vehicle speed, a transmission shift range and an engine output state, and interrupting rear wheel steering control with a safety control means. CONSTITUTION:When a front wheel steering angle sensor 23, a vehicle speed sensor 22 and a rear wheel steering angle sensor 24 are operating properly, a control signal corresponding to a front wheel steering angle is outputted from the main control means 30 of a controller to a stepping motor driver 28, thereby performing the feedback control of a stepping motor 16 or a rear wheel steering device for controlling a rear wheel steering angle to a desired value. On the other hand, when there in no output signal from the sensor 23, engine output is enough to allow a vehicle travel and a transmission shift is within a travel range respectively. a sensor faillure judgement part 35 judges that the aforesaid condition denotes the failure of the sensor 22, and outputs an OFF signal to a relay 36, thereby interrupting power supply to the stepping motor 16 and keeping the rear wheel steering angle at zero. |
