Hammerhead - A Vision Guided AUV
This paper describes the culmination of two separate programmes of work undertaken at the Offshore Technology Centre at Cranfield University. The problems of underwater vision in dark turbid water have been of interest to us over a number of years and a technique employing laser illumination has been developed to partially overcome them. The system incorporates a solid state frequency doubled cw diode pumped Nd:YAG laser emitting light at 532nm as a source of illumination. Using an oscillating mirror to form a stripe of illumination on the target, image processing techniques have been used on standard CCTV outputs to reduce backscattered light thus improving image quality and range of vision. Also, an Autonomous Underwater Vehicle (Hammerhead) has been developed for the purpose of investigating control and guidance strategies. This paper describes the implementation of the above-mentioned viewing system onto the vehicle and how data extracted from the sensor has been used in the control and guidance of the AUV. In addition, the use of image tracking software, that can be trained to recognise an object, has enabled the AUV to detect and follow a predetermined target, such as an underwater pipeline or subsea telecommunications cable – a truly bio-inspired operational technique.
Pietro VINCENZINI and Salvatore GRAZIANI
R. L. Allwood "Hammerhead - A Vision Guided AUV", Advances in Science and Technology, Vol. 58, pp. 257-265, 2008