CTG puts 3 special robots for hydropower stations into use

Three types of robots for hydropower stations developed by China Yangtze Power (CYPC), a listed arm of China Three Gorges Corporation (CTG), have been put into use recently, demonstrating their unique skills in different working spaces.

The robot for underwater inspection and maintenance, codenamed underwater dragon, consists of a host unit and a variety of add-on devices, which can work in a range of underwater environments such as the reservoir area, tail water, flow channels and culverts at a hydropower station, and dive up to 300m, compared with 60m by human under the same condition.

In addition to its exceptional ability to deep dive, the new robot also features many special skill sets including underwater shooting, scanning, salving, measuring, cleaning and cutting, effectively addressing challenges in underwater inspection and operation under the conditions of deep water and complex flow. As it can replace aquanauts to perform diving operations, the robot ensures the production safety while improving the efficiency of maintenance operations.

The robot tailored for concrete flow-path inspection is nicknamed Gecko. The 18.4kg robot can absorb on the surface of a concrete flow-path, and automatically detect and avoid obstacles. It can also automatically walk along the concrete surface or be operated through manual control remotely to detect and locate the defects on the surface as well as measure the size and depth of the areas with defects. It is the first time that such robot is used in flow-path inspection in China, also the first in the hydropower maintenance industry.

Codenamed Spiderman, the robot built for steel pipe inspection and maintenance has a diameter of 12.4m. Equipped with HD digital cameras and dot-matrix laser scanners, this robot can perform inspection missions by crawling along the dome of the giant four-story-high pressure steel pipes at the Three Gorges Hydropower Station.

The robot mainly consists of a body structure, a control system, a ground-base station and a visual inspection system. It can create 3D graphics for the space under inspection to accurately locate the defects and also perform automatic flaw detection on pressure steel pipes to accurately measure the size and depth of defects. The robot is also capable of repairing the defects by grinding, welding and painting.