| 摘要 |
PURPOSE:To promote the high efficiency of working by providing a function to an agricultural machine or the like to automatically travel in the intended direction with a light beam as a guide light provided with a light emitting device that radiates the light beam and a light receiving device of it. CONSTITUTION:A light projector 2 is set up on a ridge in a rice paddy 1 and on the opposite ridge,a target 3 for collimation respectively, and the direction of a light beam 6 is fixed. In a light receiving device 5 on a tractor 4, two photodetectors are mounted horizontally. When both photodetectors are within the light beam 6, the tractor 4 keeps straight forward. If the tractor comes off the course and either photodetector gets out of the beam 6, its output is reduced and the progressing direction of the tractor 4 is corrected to the direction which balancs the both outputs. When the tractor 4 reaches the other end, it is rotated by 1/2 turn by a touch sensor located its far end to reverse its progressing direction. At the same time, the light projector 2 moves as much as the width of tillage to a arrow mark 7, and the light receiving device 5 of the tractor revolves, and stops at the position where the max. quantity of light can be received. Thereafter, the tractor keeps straightforward in the reverse direction in the same way by the light beam 6. |
