Nishimatsu Construction and Organization for Marine Science and Technology of Nagasaki University have developed an airship-shaped tunnel inspection robot. They tested the robot in the 2.6 km water tunnel at the hydro power plant and confirmed it was capable of flying autonomously while inspecting the wall of the tunnel. The company is considering using it for inspection of deteriorated agricultural waterway tunnels.

Tunnel Mambou, named after Japanese word for a sunfish, is the multi-rotor drone which can take photographs of the whole circumference of the tunnel while flying. The equipped camera unit can also identify scratches on the wall as small as 1 cm. The 3.7 meters long robot consumes less electricity than a regular unmanned aerial vehicle and has a larger payload.

In the experiment, the wall surface of the tunnel was inspected by the robot when the water was cut off. Based on the battery consumption at the end of the inspection, it was estimated that the drone could fly up to 6 km.

Many waterway tunnels of hydroelectric power plants is deteriorating in Japan. Due to the long inspection distance and the risk of collapse, inspection by robots is much anticipated.
(2020/06/23)