| 摘要 |
PURPOSE:To detect the position between the two points which cannot be viewed from each other as in a curved tunnel by installing a laser deflector having a mirror which can be deflected by two horizontal and vertical shafts between a laser range finder and a photodetection plate to be measured. CONSTITUTION:A laser range finder A and a reference photodetection plate D are installed in the place where the ground 1 is relatively stable as in a vertical shaft 2 of a tunnel. A photodetection plate B to be measured is provided in the rear part of a shield excavator 5 and a laser deflector E is installed at the intermediate between the range finder A and the plate B. The distance between the laser deflector and the photodetection plate to be measured is measured by reflecting the laser from the range finder A with the deflector E, conducting the laser to the plate D, measuring the solid angle assumed by the incident optical axis thereof and the reflected optical axis, calculating the position of the deflector E, conducting the laser from the range finder through the laser deflector to the home position of the plate B, calculating the deviation between the indicent light to said photodetection plate and the incident light to the deflector, further reflecting said incident laser on the photodetection plate to be measured and returning this laser through the laser deflector up to the laser range finder. |
