00:00 Bruce Drinkwater, University of Bristol: ‘Ultrasonic and acoustic sensing for buried pipe inspection with swarms of robots’ – pipebots.ac.uk
Abstract: This talk reviews the future possibilities for sensing using swarm robotics. The work has been performed as part of a large project called Pipebots in which other members of the team are also progressing the robots, navigation and communications for use in water and sewerage pipes. The focus of this talk is on the acoustic and ultrasonic sensors that can detect blockages and damage, such as cracking or corrosion. Blockages are detected with relatively low frequencies, enabling wave propagation over tens of metres. These waves travel as guided waves within the pipe interior. As the robots approach the blockage, higher frequencies can be used to provide additional characterisation information. These waves can also be used to characterize the local environment, for example, determining pipe geometry or the presence of bends or junctions. Damage to the pipe wall is detected using significantly higher frequencies. These travel as guided waves within the pipewall and propagate over much shorter distances. To accurately detect damage the signals from a number of robots must be combined to increase the probability of detection. This same data can then be used to form an image allowing location and defects size to be extracted. The use of a robot swarm involves many compromises. For example, more robots add cost but leads to better detection and more accurate characterization. This talk describes how an understanding of these compromises leads to an optimal approach to swarm robotic sensing in this application.