[IROS 2012] Designing a robot that can do everything is hard. Robots work best when they’re given one specific task to perform and have been constructed with that task in mind, so if you’re trying to, say, monitor coral reefs from the air, the surface of the ocean, and under water all at once, you can either drive yourself nuts trying to come up with some sort of autonomous submersible seaplane, or you can just teach a robotic airplane, robotic boat, and robotic submarine to all work together.
This heterogeneous robotic team consists of a small autonomous UAV, an ASV (autonomous surfin’ surface vehicle), and an AUV (autonomous underwater vehicle). Here’s a rundown of the different bots and what they do, straight from the research paper:
• The Unicorn UAV is responsible for performing coverage of the entire survey region and provide up-to-date large-scale aerial imagery to the remote human scientists. After obtaining the expert-selected inspection sites, the UAV then re-broadcasts these waypoint directives to the other two robots underneath, while continuing to collect updated aerial footage of the entire region.
• The MARE ASV serves two primary roles: it is used to cache waypoint directives received from the Unicorn UAV, and it also relays these messages to the Aqua AUV when it surfaces. These roles are needed because the UAV has limited battery life, making it unable to wait until the Aqua UAV surfaces.
• The Aqua AUV is responsible for gathering ﬁne-scale imagery by performing close-up inspection of the target sites. While Aqua mainly operates underwater to navigate to these sites and collect footage, it also regularly ascends to the surface to listen for further messages from MARE and to update its localization using GPS.
The overall idea here is that researchers, safe and dry on land, can easily interact with the entire swarm (which is autonomous) in real-time, using the imagery that the UAV sends back to select locations for detailed underwater inspection by the AUV. This can even be done ultra-remotely, through a web interface, meaning that you’ll never even have to go to what looks like an exotic tropical island in person. Watch the system in action, and you’ll see how simple it is to control:
Field trials have shown that this robot team is robust enough to actually work in practice, and is in fact drastically more efficient than human divers trying to perform similar surveys. Ongoing research will allow the robot team to work in not-ideal weather, and will also expand the operating envelopes of each individual robot, meaning higher altitudes for the UAV, deeper dives for the AUV, and getting the ASV to do something besides just acting as a radio relay.
"Multi-Domain Monitoring of Marine Environments using a Heterogeneous Robot Team," by Florian Shkurti, Anqi Xu, Malika Meghjani, Juan Camilo Gamboa Higuera, Yogesh Girdhar, Philippe Giguere, Bir Bikram Dey, Jimmy Li, Arnold Kalmbach, Chris Prahacs, Katrine Turgeon, Ioannis Rekleitis, and Gregory Dudek with McGill University, Universite Laval, and University of Guelph, was presented today at the 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems in Vilamoura, Portugal.