An image-guided mobile robotic system for underground pipe navigation and condition monitoring

Abstract

This paper presents the design of a mobile robotic system for navigating inside the vertical and horizontal segments of underground pipes using visual data. The development of this system stems from the need to inspect underground pipes buried for various reasons, and for which it becomes a challenging task to inspect the interior conditions of the pipe. The specific application under study was a horizontal ground-coupled heat exchanger system for which a 160 mm diameter PVC pipework of approximately 60m length was buried at a depth of 3m below ground. The purpose of the mobile robotic system was to provide video recording of the interior of the PVC pipe network while also measuring the prevailing temperature and humidity level using on-board sensors. This paper presents the design process followed to develop the system, with emphasis on the image processing and analysis techniques for navigation along straight segments, both vertical and horizontal, of the pipe and around corners. The system design allows the robot to contract in diameter at a 90-degree elbow pipe and navigate through bends, which are detected using visual cues generated by using specific lighting arrangements.