
TOKYO -- Lightweight robots crawl over buildings' outer walls tapping on tiles in a safety inspection service recently launched by a unit of Tokyo Gas, shaving costs by a quarter compared to using human inspectors.
The roughly 20 kg BlueCrawler robot, measuring about 90 cm tall and 90 cm wide, is designed for buildings up to 20 stories high. It travels vertically on ropes lowered from roofs and is remotely controlled by an engineer.