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

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

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

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.

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

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

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

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 --- 2 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

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

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

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.

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’