Abstract
This paper describes a new mechanism, communication system, and vision system of an in-pipe inspection robot. To date, inspection robots have had such limitations as mobility of the robot to turn in a T-shaped pipe or move in a plug valve. The new mechanism based on our dual magnetic wheels overcomes these limitations without difficulty in control. This dual mechanism, resembling a crawler, enables the robot to climb over sharp obstacles like sleeve and dresser joints. Another drawback of earlier robots is that the friction between the pipe and the cables for communication and power supply makes it difficult to move a long distance. A fiber-optic communication system can reduce friction. The spooler of the fiber-optic communication cables and batteries are mounted on the robot and the cables are rolled and unrolled when the robot is going forward and backward, respectively. The new vision system has been significantly miniaturized, enabling it to clearly view and inspect the pipe welds underneath the robot while gazing ahead for navigation. The reflection of slit light made by a light-emitting diode and a cylindrical lens is used to diagnose the pipe weld.
An experimental inspection robot has been successfully made to confirm the efficiency of the new mechanism and the vision system.
