TECHNOLOGY AREAS: Ground/Sea Vehicles

ACQUISITION PROGRAM: Navy Future Naval Capability Program, Sea Shield, Defense of Harbor ...

OBJECTIVE: Design, build and test a new generation of low cost, energy efficient, silent, agile artificial fish utilizing multiple degree of freedom muscle-like actuators and shape changing body and fins.

DESCRIPTION: Although UUVs (autonomous as well as remotely piloted) are proving to be valuable for marine surveillance operations, significant improvements in efficiency, stealth, maneuverability and autonomous operation need to be achieved to fully realize the potential of these systems. Biology provides promising solutions to many of these problems but development of a successful AUV requires the combination of appropriate bioinspired solutions with state-of-the-art approaches in manufacturing, materials, controls, actuators and sensors. Flexibility (of body and fins) is a hallmark of animal swimming and is likely the key to the amazing propulsive and maneuvering capabilities of fish. AUVs that exploit this property could potentially have capabilities that far exceed current AUVs. Although considerable work has been done on understanding the propulsive characteristics of individual fish fins, a better understanding of how fish use all their fins (median, paired, caudal etc) to enhance their propulsive performance, maneuverability and stealth characteristics is needed. For instance, dorsal and caudal fins have been found to work in concert to significantly improve the thrust and propulsive efficiency. Fins not only provide propulsive forces but are used in a variety of combinations to produce maneuvering forces and to stabilize the fish which is dynamically unstable.

In addition, further advancements in affordable manufacturing techniques, and cost-efficient but effective actuators, sensors and materials are also needed. Stealth and higher efficiency can be achieved by moving away from traditional rotary electric motors to other actuators such as artificial muscles or linear, Lorenz force motors.

PHASE I: (1) Using an appropriate fish model, develop quantitative understanding of role of various fins (medial, caudal, paired) and body flexibility on propulsive performance, dynamic stability and maneuverability of the fish. (2) Develop a man-portable (<700 mm in any dimension), artificial fish breadboard prototype which employs multiple flexible fins driven by artificial muscle or other non-conventional actuators and which can self propel along a linear bearing track in a stable manner (prototype may be remotely piloted through a tether)

PHASE II: Develop and test a fully autonomous, artificial fish which is able to demonstrate the ability to maneuver along a complex three-dimensional underwater path (at depth >1 m) to a target at a distance of >50 m, acquire data (photographic, sonar or other) on the target and return to point of entry. Fully characterize the performance (propulsive, electrical, acoustic) of the artificial fish.

Investigate cooperative swimming and biological behaviors. Construct 3+ heterogeneous AUVs with different payloads capacities, AUV-AUV communications and sonar based sensing. Explore cooperative behaviors such as group synchronized swimming and turning of schools, search patterns and repositioning after loss of AUV.

PHASE III: Produce and demonstrate efficient, highly maneuverable, heterogeneous, fish based AUV platforms capable of executing autonomous individual and multi-unit, school based operations.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: The artificial fish are expected to be used in a wide variety of non military markets including: oil rig inspection, wharf and bridge pylons safety monitoring, sports fishing active lures, under water swimming robotic companion, and entertainment.

REFERENCES:
1. The Navy Unmanned Undersea Vehicle (UUV) Master Plan, Nov 9, 2004.

2. G.V. Lauder, P. Madden, R. Mittal, H. Dong and M. Bozkurttas, "Locomotion with Flexible propulsors: I. Experimental analysis of pectoral fin swimming in sunfish", Bioinspiration and Biomimetics: Learning from nature, vol. 1, S25-S34, 2006.

3. Imran Akhtar, Rajat Mittal and George Lauder "Hydrodynamics of biologically inpired tandem falpping foil configuration" Theor. Comput. Fluid Dynamics, Vol 21, Number 3 May, 2007 PP. 155-170

4. Tangorra, J. L., Davidson, S. N., Hunter, I. W., Madden, P. G. A., Lauder, G. V., Dong, H., Bozkurttas, M., Mittal, R. The development of a biologically inspired propulsor for unmanned underwater vehicles, IEEE J. Oceanic Eng., Jul 2007

5. Tangorra, J. L., Anquetil, P.A., Fofonoff, T. Chen, A., DelZio, M., Hunter, I.W., The application of conducting polymers to a biorobotic fin propulsor, Bioinsp. Biomimet. 2007; 2, S6-S17

KEYWORDS: AUV, Artificial Fish, muscle-like actuators, pectoral fin, shape changing fins, swarms

TPOC: Thomas McKenna
Phone: (703)696-4503
Fax: (703)696-1212
Email: [email protected]
2nd TPOC: Kam Ng
Phone: (703)696-0812
Fax: (703)696-2558
Email: [email protected]