Development of Snake-Like Robot for Cable-Laying —Motion Design for Locomotion over Cable Racks and Ceiling Spaces

The purpose of this study is to develop a snake-like robot for cable laying. Cable laying is one of the tasks that inevitably occur in construction work. Cable laying is generally performed manually by workers in high and narrow spaces, such as cable racks installed in ceilings and ceiling spaces. Therefore, it involves significant risks, such as falls. To ensure worker safety and enable anyone to perform the task, automation and labor-saving through robots are anticipated. Therefore, this study aims to develop a snake-like robot that pulls a lead cable through traveling wave inspired by workers’ cable-laying actions. We verify whether this traveling wave can achieve propulsion in different environments, such as flat surfaces, cable racks, and ceiling spaces, through simulations and real-world experiments. The simulation and experiment results confirm that the traveling wave is effective for propulsion in cable racks and ceiling spaces. Based on these results, it was required to keep the head horizontal to the ground even during traveling wave to allow environmental inspection using a camera mounted on the snake-like robot’s head. Therefore, we established a method to achieve propulsion with traveling wave while maintaining the head’s horizontal position using Fourier series expansion. By implementing this, we achieved propulsion with reduced head oscillation.