Morphing hull implementation for unmanned underwater vehicles

Benefits of aircraft morphing might be applicable to unmanned undersea vehicles (UUVs) as well. UUVs may perform under a wide variety of operational requirements involving slow speeds, moderate speed travel, and high speed attack/escape during execution of a single mission. Shape, size, and/or profile change, all represent morphing capabilities that could benefit the versatility and efficiency of UUVs by providing the ability to maximize the performance of each mission envelope. The primary goal of the research presented here was to construct, and test a scalable actuation system suitable for a morphing hull UUV, and to apply this actuation concept to a small scale demonstration UUV-type shell. Numerous designs were considered and one design was chosen based on its ability to achieve the desired goals, its ease of construction, and its applicability to more advanced types of morphing being considered for future work. The design chosen was a simple scissor mechanism that allows the easy conversion of a horizontal actuation force into vertical translation. The design requires low power for actuation via the use of a power screw. Increases in diameter of 80% were illustrated with the demonstrator. A natural latex skin was used to illustrate the concept of a flexible skin. This research intends to spur future ideas for UUV and submersible morphing and hence the ideas presented here represent a snapshot of morphing ideas that could be applicable to underwater vehicles. Shape morphing also has the ability to drastically change the operational regimes of UUVs, for instance making an efficient underwater vehicle capable of being an efficient surface vehicle as well. Shape morphing could also be useful in the areas of control. Typically, surface appendages, such as wings, or buoyancy control methods are used for control purposes. However, the ability to shape morph a UUV hull could make the entire UUV a control surface, eliminating the need for such appendages. For instance, if it was desired to reduce the depth of a UUV, the UUV hull could be morphed into a lifting body, such as an ellipse, that would force the vehicle to move towards the surface. Conversely, a diving body shape configuration could be assumed in the same manner. Furthermore, port and starboard controls could also be assumed using shape morphing. Sideways lifting bodies, again in the form of ellipses, could be used to steer the vehicle port or starboard.