An Industrial Robot for Firewater Piping Inspection and Mapping

摘要

The design of an industrial pipe inspection robot for 4" firewater piping inspection and mapping with some new and unreported features is presented. The robot consists of a compact 3D MEMs Lidar with non-linear scanning pattern in the form of Lissajous trajectories that produces a dense scan of inner pipe surfaces. Evaluating the surface integrals of these 3D point clouds acquired at pipe turns allow for turn direction discrimination on the horizontal plane which is not realizable using IMUs. A non-SLAM method is used for robust localization: the actual distance traveled by the robot inside a pipe network is measured explicitly by measuring tether displacement; this measurand is then used as the arc length parameter of a parametric curve. This parameterization represents the robot trajectory such that the 3D robot positions along this trajectory are defined in terms of distances traveled (arc length of parametric curve). Pose transitions measured using an on-board IMU combined with the arc-length parametric trajectory let us determine the full 6D robot pose inside featureless pipes. Instantaneous Lidar scans and the 6D poses are used to create a high density 3D map of the pipe network to help identify pipe joint deformation at cm level.