Eyes, ears and brains being developed for underwater robots
By Ben Coxworth
November 24, 2010
Engineers from Germany's Fraunhofer Institute for Optronics are working on an autonomous underwater vehicle (AUV) that would be inexpensive enough to use for industrial applications such as hull and dam inspection, yet independent enough that it wouldn’t require any kind of human control. Typically, more cumbersome but less costly remote operated vehicles (ROVs) are used for grunt work – they are connected to a ship on the surface by a tether, where a human operator controls them. The more technologically-advanced AUVs tend to be used more for well-funded research, but according to the engineers, one of the keys to creating “blue collar” AUVs is to overhaul the ways that they see, hear and think.
The project is being led by Dr. Thomas Rauschenbach. His team wants to build autonomous robots that are not only less expensive, but that are also smaller and tougher than their predecessors, and that can be used in pretty much any underwater setting.
The AUVs will reportedly be able to see even in turbid water, thanks to a laser imaging system. An onboard camera will emit laser pulses, which will be reflected by underwater objects. As the camera receives and processes these waves of reflected light, it will build up a picture of its surroundings.
Hearing, so to speak, will be accomplished via high-frequency sound waves. As with the laser pulses, these ultrasound waves will bounce off of objects and be registered by a sensor, allowing the AUV to inspect those objects. Fraunhofer believes that it is a step up from the sonar technology that similar vehicles currently use.
A control program will keep the AUV on course and out of harm’s way, even allowing for underwater currents. Its pressure-tolerant electronics will be encapsulated in silicone, as will the vehicle’s lithium batteries. The program also features an energy management system, which will conserve power and save data in the event of an outage.
A prototype will be tested in a water tank this year, with sea trial dives of up to 6,000 meters (19,685 feet) scheduled for Q3 of 2011.