Estimating the posture of pipeline inspection robot with a 2D Laser Rang Finder

Pipeline network is one of the city´s critical infrastructures, such as lots of gas pipes and water pipes exist in public utilities, factories and so on. Regular inspection is required to ensure the static integrity of the pipes and to insure against the problems associated with failure of the pipes. We have developed a pipeline inspection robot equipped with a camera which can walk in the pipes and stream back live video to the base station. In this paper we propose a new method for estimating the posture of the robot in round pipes with a 2D Laser Rang Finder (LRF) and a dual tilt-sensor by using the geometrical characteristic of the round pipes constructed with the point cloud data. Transformation matrix from the robot coordinate system to the global system is deduced. The positions and sizes of pipe defects can be calculated easily relying on the range data and images. Experiments by the inspection robot in dry smooth HDPE pipes are carried out and the results show that the proposed method is useful and valid.