A simple and novel helical drive in-pipe robot

Pipeline grids of various size and material are pervasive in today's modern society. The frequent inspection and maintenance of such pipeline grids have presented a tremendous challenge. It is advocated that only advanced robot design embedded with intelligent electronics and control algorithms could perform the job. Given the ever increasing demands for intelligent in-pipe robots, various in-pipe drive mechanisms have been reported. One of the simplest is helical wheel drives that have only one degree of freedom. All previously reported in-pipe helical drives are based on independent passive wheels that are tilted an angle. One of the major problems of current helical wheel drives is their unstable traction force. In this paper, instead of allowing the wheels to rotate independently, they are synchronized by adding a timing belt. This small change will result in significant improvement which will be highlighted in this paper. In the proposed driving method, tracking force is analyzed together with a comprehensive set of traction force measurement experiments. Both analysis and experiments have shown that the proposed mechanism has great potential for in-pipe robot drive design.