SPC ROBOT: A novel pipe-climbing robot with spiral extending of coupled differential

Pipe robot is a kind of special robot, which is used in pipe detection and maintenance for the petroleum, natural gas and other pipe environment. Traditional pipe robots are only for horizontal or gentle slope pipes and difficult to adapt cliffy pipes of different sizes. This paper developed a novel spiral pipe-climbing robot (SPC Robot), which can adapt pipes of different diameters and tilt angles. The SPC Robot is composed of a series of modules driven by three motors. Each module consists of a coupled differential transmission (CDT) mechanism, spiral travel wheels, springs, a controller and batteries. The CDT mechanism realizes power transmission among all modules by competition of speeds in outer and inner shafts. Experimental results show that the SPC Robot is valid to dexterously climb vertical pipes and self-adapt pipes of different sizes. The serial chain and trajectory of the SPC Robot are spiral and the SPC Robot can be supported while it is climbing the pipe simultaneously. The SPC Robot is easy to control, low cost and compact in structure, and suitable for pipe detection and maintenance in complex environment.