1. AUTONOMOUS LONG-ENDURANCE UAV (SMART INTERN PROJECT)
Dr. Sheehy and Ms. Ahne
Gabriel Jon Murray
Chris Pillion

2. Objective Design, Build, and Fly a UAV
Provide AIR-4.3 Hands-On UAV Experience---Development to Flight
Final Result is a Prototype Autonomous UAV
Summer 2012: Vehicle Design, Bench-Top Demonstration, and Wing Hardware

3. Background Summer 2011 Literature Survey Considered Various Missions
Selected Hand-Launched UAV
Conceptual Sketches

4. Design: UAV Airfoil: Clark Y Weight: 3.75 to 4.5 lbs 57 in. 67 in.
Wing Span 67 in.
Chord 9.84 in.
Clark-Y airfoil for main wing
Length: 52 in.
Weight: ~3.75 lbs, Design Weight: 4.52 lbs
VS: 7 in. Span, 5 in. inboard chord, 2 in. outboard chord
Rudder: 5 13/32 in. span & 1 in. chord
HS: 20 in Span, 4 in. chord
Elevator: 13 ¾ in. Span & 1 in. chord
57 in.
67 in.
10 in.

5. Design: Ground Station
RC Transmitter
Radio Controller
This controller can interface with the APM via the receiver onboard the UAV
This controller can both control the surfaces directly or via the APM (which introduces stability augmentation)
Mission Planner
Allows the creation of mission waypoints
Allows for scripting of UAV action at specific waypoints (ie what altitude to circle, etc.)
Built-in ground station software and telemetry link allows for real time updates of UAV information
Uploading of new mission possible
Video Receiver
Battery powered receiver, operating at 2.4 GHz
USB video digitizer converts analog signal to a digital signal, allowing for viewing on a computer
USB
Telemetry
Laptop with Mission Planning Software
Video Digitizer
A/V Receiver

6. Design and Requirements
How Design Satisfies Requirements
Autopilot  Autonomy and Soaring
Dimensions  Hand-Launched

7. Fabrication Composite Parts Built by Polymers & Composites Branch
Vacuum Bagging Plain-Weave Carbon Fiber
Foam Core Tooling  Wing Skin
Oven Cured
Balsa Fuselage Detailed Design/Built by Interns
Composites
Work done in Materials and Processing Branch
Composite parts formed using molds and vacuum bagging
Spars molded using rectangular bars
Wing skin has a foam mold machined
Plain-Weave Carbon fiber with epoxy used for wing structure
All components are oven cured
Balsa Fuselage
Built and designed by other summer interns
Created as a test platform for wing, as fuselage will not be built until after the wing
Also a guide to ensuring all the components fit

8. Prototype: Wing I-Beam Spar Skin --- 2 Plain-Weave Plies [0°/45°]
4 Plies of Plain-Weave
[0°/0°/45°/45°] (Flange)
[45°]4 (Web)
Skin Plain-Weave Plies [0°/45°]
Wing Built in 3 sections
The main spar is an I-beam, about 1” tall, ½” wide
The web was designed for shear loading, the flange for bending loads
The skin was made separate, with the spar being bonded into the skin
Skin broken up into 3 sections, one 27 inch inner section and two 20” outer sections
Inner section connects to the fuselage
For the outer portions of the wing, the aft 1.6” is removed to make room for the ailerons
I-Beam Spar
20 inch
27 inch
20 inch

9. Testing/Prototype Propulsion Test Tested in Structures Lab
Strain-Gauged Cantilevered Beam
Thrust vs. Throttle Setting
Propulsion Test
Conducted in Structures labs
Corey created a strain gauge testing apparatus
Calibrated using known weights
Static thrust test was conducted measuring both thrust and motor voltage
Thrust and throttle setting nearly linear
2.5 lbs of Static Thrust Yields a 2/3 Thrust to Weight Ratio

10. Prototyping/Testing: HIL
Hardware-in-the-Loop Simulation and Testing
HIL simulation
Xplanes allows for the creation of your own aircraft
The flight planning software can interface the APM with Xplanes
Xplanes provides the GPS and acceleration data, which the mission planner send to the APM
The APM can perform its 3 modes of operation: RC mode, stability augmentation, and autonomous flight
The APM will actuate control surfaces if they are hooked up, allowing for both software and hardware to be tested
Allows for complete testing of each flight, including any additional or modified code
X-Plane Allows the Creation of Your Own Aircraft

11. Future Activities Construction of Composite Fuselage
Structural Test of the Wing and Fuselage
Propulsion Test with Various Propellers
Potential Analysis for Aeromechanics Division?
Flight Tests
Structural Test of the Wing
A second wing will be made for structural testing
The results from the test can be compared with the finite element analysis, allowing for verification
Test to failure could provide feedback to the M&P group, regarding their construction methods
Propulsion Test with Various Propellers
Only one propeller type was tested
Various propellers have been ordered, testing each would provide feedback on which propeller/motor combination is best
Might provide the aeromechanics division test data to compare any analysis they may conduct
Flight Tests
Actual flying on the UAV, with composite fuselage
A rigorous flight testing would provide more detailed information about the aircraft, help with fine tuning Xplanes model.

12. What I Learned Team Management and Interaction Project Management
Aeromechanics, M & P, Structural Testing
Project Management
From Requirements to Construction
Budgeting
$17,500 in Materials and $10,000 in Labor
Purchasing/Contracts
Experience Translates to Future
Team Management
Worked with people across various branches: Airframe technology, Aeromechanics, M & P, and the Structural Test Group
Worked with both NAVAIR employees as well as other interns
Project Management
Took project from requirement to construction
Adapted plan based on current situation (eg. Purchasing delays, fuselage delay)
Budgeting
First time actually given money for a project
Learned about labor costs
Purchasing
Learned about how to purchase at NAVAIR
Learned about requirements and limitations to make purchases
Areas need improvement
Better communication with and organization of the team
Ensuring my intent is understood by all
Assuming a leadership position
Foreseeing long-lead items
Better scheduling
Adaptability to change
Getting out of ‘Academic Mentality’