To prevent a vehicle from moving in a direction out of driver's intention in the case where a moving distance sensing means of an automatic steering device goes in failure.
Two front wheel rotating angle sensing means Sa3 an Sb3 are installed on one vehicle wheel, and on the basis of pulses outputted by these means Sa3 and Sb3, the first 13a and the second moving distance sensing means 13b sense two moving distances Xa and Xb. A comparing means 14 compares the two obtained vcalues of Xa and Xb, and when the difference between the two values or their ratio lies outside the specified range, judgement is passed that either of the means Sa3 and Sb3 has gone in failure. At this time, an automatic steering control interrupting means 16 sends an automatic steering control interrupting command signal to a steering actuator driving means 17. Thereby the automatic steering control is interrupted to prevent the vehicle from moving in any direction out of driver's intention.
TSUNODA RYUICHI
SAKAI KATSUHIRO
