Novel brush drive robotic tractor for sewer and water main inspection and maintenance

Abstract

This paper describes a novel drive mechanism for a robotic tractor for traversing pipelines, including sewers, in a poor condition. Traction is obtained by the reciprocating motion of two cylindrical brushes of a diameter larger than the pipe bore. The brushes move forwards down the pipe but grip the pipe wall to resist backward translation. A simple analytical model of the gripping mechanism is described. Three tractors here have been designed, manufactured and used on 20 field trials. The sewers inspected were initially considered to be uninspectable using conventional tractors. The novel tractors were easily able to deal with the majority of the sewers and the paper describes the three most difficult cases, illustrating the considerable capability of the tractors to deal with extremely poor sewer conditions.