Localization method using planar LiDAR for mobile robots to support bridge inspection

In recent years, the deterioration of infrastructure facilities such as bridges has become a problem. Precautionary measures such as visual inspections and repair by humans are in place as countermeasures for aging, but there are problems with cost and safety in such inspections. If inspection by robots becomes possible, both will be improved, which will greatly contribute to the maintenance of infrastructure facilities. In this paper, we propose a localizational position specifying system for a robot supporting bridge inspection of the moving robot under the bridge to support inspection of the bridge. Since the robot must travel on the steel structures at the bottom of the bridge, strong permanent magnets need to be installed on the edge parts in the wheels. Also, it is not possible to receive the coordinate information from the satellite as it travels at the bottom of the bridge. Therefore, a 1-dimensional low-cost LiDAR sensor and a stepping motor are used to implement as a planar LiDAR sensor which rotates 360 degrees, specify the position of the current robot by obtaining distance and direction data from fixed feature points. The localizational position specification through the planar LiDAR are examined by the experiment. As a result, it was possible to estimate the localizational position of the robot.