Date of Award

2013

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical and Aerospace Engineering

Committee Chair

Nathan Slegers

Committee Member

Ken Zuo

Committee Member

Farbod Fahimi

Committee Member

Babak Shotorban

Committee Member

Kader Frendi

Subject(s)

Micro air vehicles, Ornithopters, Drone aircraft

Abstract

Articulated micro air vehicles are a class of micro air vehicles comprised of a main center body attached to outer wings on both sides. As in the case of a single rigid micro air vehicle, the center body and the attached bodies in the articulated case are all responsible for the generation of aerodynamic forces and moments during flight resulting in a multibody system. While many approaches have been taken in the literature to model the system of equations resulting from such a complicated multibody system, this dissertation presents an approach based on a Newton-Euler multibody dynamics formulation where the multiple bodies are attached together with suitable joints. The number and type of joints determines the level of articulation and total degree of freedom for the entire system. Unlike most articulated air vehicle model formulations available in the literature, the final model formulation presented in this work provides joint force and moment data acting on the articulated MAV during flight. This feature allows such information to be available during the vehicle design and development stage where appropriate spring and dampers for the system are selected based on mission requirements. Experimental validation of the proposed mathematical model using experimental flight test data obtained from UAHuntsville's Autonomous Tracking and Optical Measurements laboratory allowed the comparison of the flight test results and model simulations. Analytical investigation of the gust alleviation properties of the articulated 8 degree-of-freedom micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes and shows that the passive articulation in micro air vehicles increases their robustness to gusts when suitable joint parameters are selected.

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