Development of Visual Simultaneous Localization and Mapping (VSLAM) for a Pipe Inspection Robot

This paper describes a visual simultaneous localization and mapping (VSLAM) method for a pipe inspection robot that can serve as a carrier for nondestructive testing (NDT) sensors inside in-service water mains. The proposed method features a multi-sensor fusion system that simultaneously executes two important functions of the robot: construct a global image of the internal surface of the pipe and provide the location of the NDT sensors. The fusion involves a synergy between image mosaicing and dead reckoning. More precisely, the sequential images of a digital camera are stitched together with the help of an inertial navigation system (INS). In the proposed model, the processing load of image mosaicing is reduced significantly, and at the same time the accumulation of error of the INS is prevented. The functionality of the model is verified using a simulator that mimics the motion of a pipe inspection robot inside a water main.