Inspection method in underdrain by underwater robot

摘要

PURPOSE:To inspect the inner wall surface of culvert even when the upstream side opening is small by a method in which a cable connected with an object to be towed is allowed to flow downwards from the upstream side opening to the downstream side opening, and an underwater robot is provided to the cable at the outlet and moved in the culvert toward the upstream. CONSTITUTION:A cable 15 connected to an object 20 to be towed is allowed to flow from the first opening 12 of an insufficient area to put an underwater robot 13 into it toward the large opening 14 on the downstream. The object 20 is drawn up at the opening 14 and the robot 13 is attached to the cable 15 which is in turn carried into the water of the culvert. While moving the robot 13 against the flow of water, the inner wall surface of the culvert is inspected by using a television camera. The cable 15 is again sent out, and the robot 13 is positioned on the opening 14 to pull it up. The object 20 is again attached to the tip of the cable 15, the cable 15 is wound up by a cable winch 16, and the object 20 is positioned on the opening 13 to recover it.