THESIS
2019
xii, 102 pages : illustrations ; 30 cm
Abstract
The past few decades have witnessed a dramatically growth of unmanned aerial vehicle
(UAV) market. Such an increasing requirement of UAV also caused fierce competition
among UAV companies all over the world. For these UAV manufactures and relative researchers,
optimization of UAV design is critical to improve performance of UAVs. Compare
to all other configurations of UAVs, winged UAV is the most complex and difficult
to optimize during the design progress. That is not only because of the involved complex
aerodynamic model, but also due to the coupling of aerodynamic model and propulsion
system model, which composed by several sub-models, such as battery model, propeller
model and motor model. In this thesis, a powerful model based optimization framework
is proposed to design h...[
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The past few decades have witnessed a dramatically growth of unmanned aerial vehicle
(UAV) market. Such an increasing requirement of UAV also caused fierce competition
among UAV companies all over the world. For these UAV manufactures and relative researchers,
optimization of UAV design is critical to improve performance of UAVs. Compare
to all other configurations of UAVs, winged UAV is the most complex and difficult
to optimize during the design progress. That is not only because of the involved complex
aerodynamic model, but also due to the coupling of aerodynamic model and propulsion
system model, which composed by several sub-models, such as battery model, propeller
model and motor model. In this thesis, a powerful model based optimization framework
is proposed to design highly efficient winged UAVs powered by electric motors. In the
proposed approach, the models of aerodynamic configurations and propulsion system are
built and cast into an unified optimization problem, where the optimization objective is
the design goal (e.g.
flight range, endurance). To evaluate the models, the key design
variables are parameterized as two groups, which respectively denote the aerodynamic
model (e.g. wing span, sweep angle, chord, taper ratio, cruise speed and angle of attack)
and the propulsion systems model (e.g. propeller, motor and battery). Moreover,
practical constraints are naturally incorporated into the design procedures as constraints
of the optimization problem. These constraints may arise from the preliminary UAV
shape and layout determined by industrial design, weight constraints, etc. The optimization
framework is inherently non-convex and involves both continuous variables (e.g. the aerodynamic configuration parameters) and discrete variables (e.g. propulsion system
combinations). To solve this problem, a novel coordinate descent method is proposed.
Trial designs show that the proposed method works rather efficiently, converging in a few
iterations. And the returned solution is rather stable with different initial conditions.
And then, the entire approach is applied to design a quadrotor tail-sitter VTOL UAV.
The designed UAV is validated by intensive real-world
flight tests. Finally, the optimal
UAV completed a mapping task and build a 3D map of a construction site.
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