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Full-Text Articles in Engineering
The Characterization Of Material Properties And Structural Dynamics Of The Manduca Sexta Forewing For Application To Flapping Wing Micro Air Vehicle Design, Ryan P. O'Hara
Theses and Dissertations
The Manduca Sexta species of moth serves as a source of biological inspiration for the future of micro air vehicle flapping flight. The ability of this species to hover in flapping flight has warranted investigation into the critical material, structural, and geometric properties of the forewing of this biological specimen. A rigorous morphological study of the Manduca Sexta forewing was conducted to characterize the physical and material properties of the biological forewing for the purpose of developing an advanced parametric three dimensional model finite element analysis (FEA) model. This FEA model was tuned to match the experimentally determined structural dynamics …
Development Of Photographic Dynamic Measurements Applicable To Evaluation Of Flapping Wing Micro Air Vehicles, Jeremy C. Murray
Development Of Photographic Dynamic Measurements Applicable To Evaluation Of Flapping Wing Micro Air Vehicles, Jeremy C. Murray
Theses and Dissertations
Developments in the area of flapping wing micro air vehicles (FWMAVs) of a small size and with limited range. This has lead to a great deal of interest in biomimetric designs based on flapping wing flyers, including the North American Hawkmoth (Manduca Sexta). By utilizing high speed photography and photogrammetry the dynamic flapping of the wing can be characterized for comparison with mathematical models, namely computational fluid dynamics (CFD) and finite element analysis (FEA).To successfully utilize high speed image capture, a method of successfully digitizing many data points in a short period of time needs to be developed. The effort …
A Photogrammetry-Based Hybrid System For Dynamic Tracking And Measurement, Daniel P. Magree
A Photogrammetry-Based Hybrid System For Dynamic Tracking And Measurement, Daniel P. Magree
Theses and Dissertations
Noncontact measurements of lightweight flexible aerospace structures present several challenges. Objects are usually mounted on a test stand because current noncontact measurement techniques require that the net motion of the object be zero. However, it is often desirable to take measurements of the object under operational conditions, and in the case of miniature aerial vehicles (MAVs) and deploying space structures, the test article will undergo significant translational motion. This thesis describes a hybrid noncontact measurement system which will enable measurement of structural kinematics of an object freely moving about a volume. By using a real-time videogrammetry system, a set of …
A Structural Dynamic Analysis Of A Manduca Sexta Forewing, Travis W. Sims
A Structural Dynamic Analysis Of A Manduca Sexta Forewing, Travis W. Sims
Theses and Dissertations
Micro air vehicles (MAVs) are intended for future intelligence, surveillance, and reconnaissance use. To adequately fulfill a clandestine capacity, MAVs must operate in close proximity to their intended target without eliciting counter-observation. This objective, along with DARPA’s constraint of a sub-15 centimeter span, requires future MAVs to mimic insect appearance and flight characteristics. This thesis describes an experimental method for conducting a structural analysis of a Manduca Sexta (hawkmoth) forewing. Geometry is captured via computed tomography (CT), and frequency data is collected using laser vibrometry in air and vacuum. A finite element (FE) model is constructed using quadratic beams and …
Waypoint Generation Based On Sensor Aimpoint, Shannon M. Farrell
Waypoint Generation Based On Sensor Aimpoint, Shannon M. Farrell
Theses and Dissertations
Secretary of Defense Robert M. Gates has emphasized a need for a greater number of intelligence, surveillance, and reconnaissance (ISR) assets to support combatant commanders and military operations globally. Unmanned systems, especially MAVs, used as ISR platforms provide the ability to maintain covertness during missions and help reduce the risk to human life. This research develops waypoint generation algorithms required to keep a point of interest (POI) in the field of view (FOV) of a fixed sensor on a micro air vehicle (MAV) in the presence of a constant wind.
Fixed sensors, while cheaper and less prone to mechanical failure …
Real-Time Navigation And Flight Path Generation For Tracking Stop-And-Go Targets With Miniature Air Vehicles, Nate A. Terning
Real-Time Navigation And Flight Path Generation For Tracking Stop-And-Go Targets With Miniature Air Vehicles, Nate A. Terning
Theses and Dissertations
This research effort focuses on using a heuristic approach to determine the optimal flight path required to put an Unmanned Aircraft System’s (UAS) sensor on a moving target in the presence of a constant wind field. This thesis builds on past work using dynamic optimization techniques to calculate minimum time to target. The computationally intensive dynamic optimization routines in their current form take a prohibitive amount of time to calculate and ultimately result in erroneous flight path predictions due to inherent execution time latencies. Therefore an iterative, suboptimal heuristic approach was explored to mitigate excessive calculation times and ultimately yield …
Toward A Flying Mems Robot, Nathan E. Glauvitz
Toward A Flying Mems Robot, Nathan E. Glauvitz
Theses and Dissertations
The work in this thesis includes the design, modeling, and testing of motors and rotor blades to be used on a millimeter-scale helicopter style flying micro air vehicle (MAV). Three different types of motor designs were developed and tested, which included circular scratch drives, electrostatic motors, and comb drive resonators. Six different rotor designs were tested; five used residual stress while one design used photoresist to act as a hinge to achieve rotor blade deflection. Two key parameters of performance were used to evaluate the motor and rotor blade designs: the frequency of motor rotation and the angle of deflection …
Experimental Methods To Characterize Nonlinear Vibration Of Flapping Wing Micro Air Vehicles, Adam P. Tobias
Experimental Methods To Characterize Nonlinear Vibration Of Flapping Wing Micro Air Vehicles, Adam P. Tobias
Theses and Dissertations
For urban combat reconnaissance, the flapping wing micro air vehicle concept is ideal because of its low speed and miniature size, which are both conducive to indoor operations. The focus of this research is the development of experimental methods best suited for the vibration testing of the wing structure of a flapping wing micro air vehicle. This study utilizes the similarity of a beam resonating at its first bending mode to actual wing flapping motion. While computational finite element analysis based on linear vibration theory is employed for preliminary beam sizing, an emphasis is placed on experimental measurement of the …
Finite Element Solution: Nonlinear Flapping Beams For Use With Micro Air Vehicle Design, Robert L. Walker
Finite Element Solution: Nonlinear Flapping Beams For Use With Micro Air Vehicle Design, Robert L. Walker
Theses and Dissertations
The development and use of Micro Air Vehicles is becoming more and more important to the military. Size, weight, maneuverability, stealth, and fuel consumption are just some of the constraints on a future Micro Air Vehicle. Perfect blueprints for a small scale flying machine are both insects and humming birds. Medium sized hummingbirds are found to have wings-beats at a frequency of 18-28 Hz. There is a vast amount of complexity to just how these creatures can create lift; however, this study looks at different beams made of common materials with 1st natural bending frequencies in this range. This study …
Three Component Velocity Measurements In The Tip Vortex Of A Micro-Air-Vehicle, Hong-Joon Park
Three Component Velocity Measurements In The Tip Vortex Of A Micro-Air-Vehicle, Hong-Joon Park
Theses and Dissertations
The purpose of this research was to improve the MAV that will be used for battle damage assessment and reconnaissance or local surveillance through the experiments in AFIT wind tunnel. The experiments were performed to investigate the wing displacement and wing tip vortex interaction. To conduct the experiments, telescopic survey tool and tri-axial hot-wire anemometer was utilized. The results indicate that wing tip displacement of the flexible wing was approximately 8 times that of the rigid wing in an unstalled condition and data suggests that flexible wing has a denser core-distribution of velocity within the wing tip vortex and delays …
Experimental Analysis Of Propeller Interactions With A Flexible Wing Micro-Air-Vehicle, Brian J. Gamble
Experimental Analysis Of Propeller Interactions With A Flexible Wing Micro-Air-Vehicle, Brian J. Gamble
Theses and Dissertations
An investigation into the effects of the propeller slipstream on a flexible wing micro-air-vehicle (MAV) was conducted. The Air Force Research Lab, Munitions Directorate designed a man-portable MAV with a 24 in. wingspan and 6 in. root chord to be used for battle damage assessment and reconnaissance. Two wings have been developed for this MAV. One is a rigid carbon-fiber wing and the other consists of flexible parachute material attached to a carbon-fiber skeleton. Experimental methods were implemented to investigate propeller and wing interactions, characterizing torque and thrust requirements on the motor along with aerodynamic forces on the aircraft as …