This project will create flight control methods for a new class of unmanned aerial vehicle (UAV) with feather-like appendages and shape-changing planform, designed based on deep understanding of how birds maintain stability and respond to flow disturbances while gliding in unpredictable environments. This project includes the development of 3D printed artificial feathers, with integrated sensing and actuation. The main purpose of the artificial feathers is to provide a passive control component, by appropriately deflecting in response, for example, to a wind gust. A larger but slower active control component is supplied by an articulated support structure based on a bird wing, whose shape can be changed depending on flight conditions and desired maneuvers. Avian studies will explore the aerodynamic contributions of both passive feather flexibility and active wing shape control. The resulting knowledge will be translated to the UAV using distributed computing and control. The new generation of UAVs resulting from this project will have increased mission versatility and greater survivability in unknown turbulent environments. These improved capabilities will be valuable for monitoring fires, delivering rescue supplies, and accomplishing searching and rescue missions. The ability to remain stable despite wind gusts and other environmental disturbances is also a key element for safe flight as these platforms are increasingly deployed in crowded urban environments. Outreach programs based on the wind tunnel experiments and field studies associated with this grant will be used to inspire a diverse group of young people to enter STEM programs.
The project goals include modeling of passive and active mechanics of 3D printed materials with embedded sensing and actuation capabilities for artificial feather-like components and employing novel 3D printing methods to develop UAV structures with elbow and wrist-type joints capable of implementing avian flight control strategies. Piezoelectric materials will be used for sensing and fine-scale control of the feather-like elements, while hydraulically amplified electrostatic actuation will be used in the morphing planform. Detailed nonlinear simulations will be used to capture the nonlinear fluid-structure interactions including the highly deformable feather elements. A combination of model-based and data-driven hierarchical control strategies will be used to translate observed avian flight behaviors to the UAV. Experiments will capture avian response to flow disturbances, including active (muscle-powered) and passive (feather deflection) wing morphing, augmented by detailed measurement of feather attachment, mechanical properties of feathers and wings, neuromorphic computing, and deflection measurements in near-field flows. A compliant wing test bed will complement the avian experiments in steady and unsteady loading environments through wind tunnel testing over a range of flow conditions.
This project is jointly funded by the National Science Foundation and the US Air Force Office of Scientific Research.
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.
