| 摘要 |
PURPOSE:To avoid the detection mistake of a point marker owing to the soil of a line and also to attain the steering control even when a point marker is detected, by using a tape having a higher reflection factor than a white tape serving as the line for the point marker. CONSTITUTION:A point marker 21 having a higher refrection factor than a white tape 10 is provided to said tape 10. Comparators 22 and 23 to which the reference value E is set are added to discriminate the tape 10 from the marker 21. Then it is decided that an automatic travelling truck has passed the marker 21 from the change of outputs of both comparators 22 and 23. The steering control is also carried out even when a detector 7 passes the marker 21 since the output levels of comparators 13 and 14 have no change. As a result, it is possible to avoid the detection mistake of the marker 21 due to the soil of a line. Furthermore the steering control is possible even when the marker 21 is detected. |
