Small Pipe Inspection Robots with Wireless Communication Using Microwave Guided Modes Propagating Along a Pipe Wall

In recent years, infrastructure facilities have been noticeably deteriorating and need to be inspected. The use of pipe-inspection robots has been investigated, but the robots developed so far are too large for smaller pipes. As the robot is downsized, however, the cables used for communication and power transmission disturb the movement of the robot. In this report, we utilized microwave guided modes propagating along a pipe wall as a communication method. An experimental robot platform for small-diameter pipe inspection was constructed. We confirmed the feasibility of the communication method by conducting a 3D electromagnetic field simulation and experiments on the transmission properties. In particular, the experiments on data communication and picture transmission demonstrated the possibility of communication with the robot. A small pipe-travelling robot platform for experiments on wireless communication was designed and fabricated. We confirmed that the prototype robot was able to communicate wirelessly by using microwave guided modes propagating along the pipe wall.