| 摘要 |
PURPOSE:To transmit the information on the present position of a working vehicle by detecting the phase difference between two guiding beams based on the difference of light receiving times. CONSTITUTION:When a phase difference is produced between the scanning directions of two guiding beams A1 and A2, a time difference is produced accord ing to the phase difference between the time when one of two light receiving units S1 and S2 receives one of both beams A1 and A2 and the time when the other light receiving units receive the other beam respectively. Thus the phase difference is detected between the scanning directions of beams A1 and A2 based on the receiving time difference between both beams. Then a specific path number, i.e., a specific working area can be identified based on the phase difference. Thus, the information on the present position of a working vehicle V can be transmitted. |
