2019 年 37 巻 6 号 p. 514-522
Many social infrastructures in Japan have been intensively developed since the period of high economic growth, and the aging of them is progressing. Therefore, periodic inspections and repairs are necessary. Inspections require huge costs and take a long time because inspectors visually inspect bridges directly using scaffolds or special cranes. Practical bridge inspection robots are strongly required to reduce the costs and time associated with inspection of bridges. In recent years, various robots have been developed for bridge inspections. However, many of these robots lack the ability to locomote within inspection areas. Therefore, there are many paths which they cannot move under the three-dimensional complex environments of actual bridges. Practical bridge inspection robots are required to be able to transition between a horizontal plane and a vertical plane. Additionally, they are also required to be capable of traveling through bolted splicing parts. However, robots capable of running through these paths have not been reported. We developed a compact wall-climbing robot BIREM-IV which is equipped with four rimless wheels as driving wheels. Strong permanent magnets are attached to its rimless wheels. Therefore, the robot can move around while adsorbing on a steel structure. Furthermore, the running performance of the robot was examined by experiments. It was confirmed that this robot can easily run through bolted splicing parts. Moreover, this robot can surely transit among floor, vertical wall, and ceiling without falling from the structures.