Design, Development, Dynamic Analysis, and Control of a Pipe Crawling Robot

Well functioning water networks are essential to the sustainability of a community. Large transmission and distribution water mains are often the most sensitive components of these networks since their failure can be catastrophic. Furthermore, due to the high cost of these pipes, the system does not usually provide redundancy to enable decommission for maintenance and rehabilitation. Hence, failure of suchwater mains often carries severe consequences including loss of service, severe damages and water contamination. Aging water mains often suffer from corrosion, tuberculation or excessive leakage. These problems can affect water quality and decrease hydraulic capacity of the mains contributing to water loss. In some cases, the main may be structurally weak and prone to breakage. Prevention and/or early detection of such catastrophic failures need a comprehensive assessment of pipe condition. A proactive inspection approach is critical to the condition assessment as well as cost-effective repair and renewal of water mains. Regular cyclic inspections can provide information on the physical conditions of the pipes and on the rates of material deterioration. Nondestructive/non-intrusive technologies for evaluating pipe condition are essential tools for the early detection. However, more research is required to adapt existing technologies to the unique circumstances of large water mains that cannot be taken off service. In this context, a robotic pipe crawler as an example of underwater robotic vehicles is designed to carry pipe inspection instruments including Nondestructive Testing (NDT) sensors used for inspection of in-service water mains of different materials. The robot can also provide real-time visual information about the interior surface of the pipe. The visual information and NDT data are synergistically used to make a more reliable decision about the condition of the pipe. The on-board sensors would serve two purposes, namely (1) provide information for navigation and control of the robot, and (2) collect inspection data that can be post-processed. The proposed system has the following features: