NSF Award
2334994
Under this Foundational Research in Robotics (FRR) project, a team of researchers from Tuskegee University and Purdue University will investigate origami structures to create extendable wings for unpiloted aerial vehicles (UAVs), with four gimballed propellors capable of operating vertically in rotorcraft mode or horizontally in fixed-wing mode. Wing extension and retraction is always performed in rotorcraft mode, respectively just before or just after gimballing of the propellors. The shape-morphing capability will allow solar cells mounted on the wing surfaces to prolong fixed-wing operations, while enhancing agility and reducing vulnerability to wind gusts in rotorcraft flight. The project will also create associated algorithms for flight control and mission planning, to stabilize the rotorcraft mode during wing extension and retraction, to stabilize the aircraft during propellor gimballing, and to set rotorcraft and fixed-wing flight profiles and transition points based on mission requirements, characteristics, and constraints. Many UAV missions will benefit from the extended operational time, multifunctionality, and increased mobility conferred by the shape morphing wing and solar cells. These include surveillance and reconnaissance, search and rescue, and precision agriculture. Experiments will be conducted to demonstrate and optimize the performance of the new vehicle under a variety of realistic objectives and conditions. Additionally, joint educational activities will create communication and collaboration channels for faculty and students from both universities, laying the foundation for a continued and expanded partnership between the Tuskegee University Aerospace Science Engineering Department and the Purdue University Aeronautics and Astronautics Department.<br/><br/>The technical challenge addressed by this research is that extending mission times requires a high surface area for mounting photovoltaic cells, however high surface areas correspond to high aerodynamic disturbance forces that may overwhelm the capabilities of the aircraft in rotorcraft mode. The solution explored in the research is to use morphing wings based on Miura folding patterns that extend for fixed wing operation and retract for rotorcraft operation. Features of the Miura fold patterns may be exploited to implement control surfaces equivalent to ailerons, flaps, and slats. The research approach encompasses design of a platform for integrating solar panels with hybrid UAVs, development of guidance and actuation strategies for a shape-morphing wing, implementation of learning-enabled control laws for efficient rotor conversion, and the establishment of a laddered procedure for system performance evaluation. Optimization algorithms are employed to improve computational efficiency and scalability for complex system design. The learning-enabled control framework enables real-time optimal control with reduced data training requirements. Through these technical efforts, the project seeks to have a significant impact on safety, reduced manpower, energy savings, and insights for future unmanned aerial systems.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
