Flying Fish: An Autonomous Unmanned Aerial Vehicle for Persistent Ocean Surveillance

Developed for DARPA's Persistent Ocean Surveillance Program, Flying Fish is an autonomous Unmanned Aerial System that monitors the ocean as a drifting buoy but repositions via flight. Conceived from the notion that it is more efficient to fly over waves than to motor through them, the vehicle has a seven-foot wingspan, dual-pontoon, electric twin-engine design with an operating weight of approximately 19 pounds. The traditional wing and dual-boom tail were devised to be aerodynamically stable and efficient during flight, while the two-pontoon stepped hull system maximizes hydrodynamic stability while promoting rapid, minimum-drag takeoffs with spray directed away from the airframe. The structure was manufactured primarily form composite materials with watertight enclosures for avionics and power systems. The avionics system includes custom flight management code with full inertial navigation and long-range communication systems. Tests at a local lake progressed from radio-controlled to fully-autonomous flight. A two-day open ocean demonstration was conducted in Monterey Bay during October 2007. During this test FlyingFish successfully completed 22 fully-autonomous flights in a complex sea of 5.2 swells at 11 seconds with 2.3 feet seas at 4 seconds and light winds between 14-16 kts. Flying Fish is believed to be the first seaplane UAV to have achieved fully-autonomous (self-initiated) flight from takeoff through landing.

Continuing Flying Fish research efforts are focused toward onboard energy harvesting, augmentation of onboard sensing capabilities, and improved onboard strategic and tactical decision-making. These enhancements will make the UAV "drop and go", independent of ship or shore support long-term. Numerous Great Lakes and open ocean monitoring and surveillance applications are envisioned that will employ one vehicle or a coordinated team.

The Flying Fish project is a collaborative effort among Univeristy of Michigan researchers from Aerospace Enginering, Naval Architecture and Marine Engineering (NAME), and Electrical Engineeirng and Computer Science departments. Aerospace Engineering investigators include Ella Atkins, Luis Bernal, and Peter Washabaugh. Guy Meadows from NAME is the principal investigator.

Figure 1: Flying Fish Prototype and its Avionics Pod.

Figure 2: Flying Fish on Approach in the Open Ocean.

Figure 3: Dolphins explore Flying Fish in Monterey Bay.