| 摘要 |
<p>PROBLEM TO BE SOLVED: To lay an optical fiber cable without crossing a branch opening by selecting the upper wall surface in a sewer conduit except the branch openings as the fixing position of the optical fiber cable using a sensor for recognizing the profile of the upper wall surface in a sewer conduit and then controlling a driving machine of hook for securing the optical fiber cable. SOLUTION: When an optical fiber cable is laid, a sensor 15 for recognizing the profile of the upper wall surface in a sewer conduit recognizes branch openings and the inner wall surface of a sewer conduit 25 except the branch openings. An optimal position is then operated such that the head between the inner wall surface of a sewer conduit 25 except the branch openings and the water level of sewage will be as high as possible and the laying length of the optical fiber cable is shortest. That information is transmitted to a driver on a tubular bearing base 19 which is then turned up to an optimal position and the optical fiber cable 111 is secured to the inner wall surface of the sewer conduit 25 together with hooks 81. Consequently, the optical fiber cable 111 can be laid not to cross but to detour the branch opening.</p> |
