Critical Design Review. Almog Dov Assaf Aloush Bar Ovadia Dafna Lavi Orad Eldar. Supervisor: Dror Artzi

Transcription

1 Critical Design Review Almog Dov Assaf Aloush Bar Ovadia Dafna Lavi Orad Eldar Supervisor: Dror Artzi

2 Man-portable UAV Over the hill / Urban surveillance Fast field deployment Endurance: 3 min Simple to operated by one man Real time video camera Quiet Portable Ground Control System (PGCS) Fully automated flight (including take-off and landing)

3 Single operator Unskilled operator Simplicity of recovery Over line of sight capabilities INNOVATION as students project No launcher small size UAV Automated flight, Safe takeoff/landing No parachute and/or airbag Fixed wing Separate propulsion systems Cavitis Closing mechanism Vertical takeoff and landing. Fully automated flight. Ability to fly as a fixed wing aircraft. No tilted rotors, to avoid complicated control system

4 Conceptual design: Flying wing 3 Vertical takeoff and landing motors One horizontal motor. Chosen components: motors, propellers, batteries, payload. Conducted a thrust test for the vertical motor and propeller.

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6 Components: 1 payload 3 Vertical motors 1 Horizontal motor 4 electronic speed controllers 3 Batteries 1 Autopilot Installation principles: Weight and balance Keep CG. In place. Accessibility maintenance.

7 Payload: NextVision MicroCam D Autopilot: Micropilot 2128HELI Battery: Thunder Power RC G6 Pro Lite 25C 27mAh 4S ESC: X4 Turnigy Super Brain 6A Brushless Motor: X3 Hacker A3 14L Propeller: APC 1X5 propeller Batteries: 2X Turnigy nano-tech 45mah 6S Hacker A5 Motor Zinger 3 Blade 15X7 propeller Servo: Futaba S3156

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9 Leading edge spars. Trailing edge spars. Ribs. Mid fuselage reinforcement.

10 Motor mount structure: Upside down vertical motors Shutters

11 Work under bending load. Wing area is.9[m^2] The.45[m] span wing is subject to 2.25[kg] force. Wing load is 25[Kg/m^2]. Under 3.8G (Normal category) the wing load equals to 95[Kg/m^2].

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13 Web Flange 2 Spars: One main spar and one trailing edge spar. Tip and root ribs Main spar cross-section: Flange

14 Web and flange material Carbon Fabric (45deg) Flange support Carbon unidirectional (UD)

15 17mm 1 35mm 21mm Main spar: Web height forced by wing geometry Flange Width Calculated by bending load analysis under the assumption of constant thickness of 1mm Root 3mm 1mm Tip 16mm 1mm Trailing edge spar: Web height forced by wing geometry Flange Width Designed for smooth operation of the aileron control system Root 2mm 1mm Tip 2mm 1mm

16 Main spar at 25% chord. Trailing edge spar parallel to the ailerons hinges line. TE spar Main spar Skin

17 To minimize drag, ailerons control system is located inside the wing. Piano hinge Servo Control rod Aileron o Enough torque for our use o Small weight o Reliability

18 Root and tip ribs EPPLER 334 airfoil shaped Tip is made of 1mm carbon fabric Holes for electrical wires Connection to the winglets Root is made of 3mm carbon fabric Holes for electrical wires Supports the outer wing spars

19 Connection to the main body is made by two spars Tip rib Main spar Root rib Trailing edge spar

20 Iris system: Shutters system:

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22 Closed iris Half closed iris - Top ring rotates Opened iris

23 Top ring Base ring Iris segments top and bottom view

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25 Dimensions: Rings: Inner dimension 1 Outer dimension 13 Thickness 2mm Segments: Thickness.2mm each Total thickness - 1mm 28 segments (5 segments overlapping with.5 degrees angle) Total thickness 5mm Max diameter 13

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27 Dimensions: Ring: Inner ring diameter 1 Outer ring diameter 1.4 Thickness 5mm Shutters: Height 3mm Thickness 1mm Cable: diameter 2mm Total thickness 5mm Max diameter 1.4

28 Iris Shutters Mechanism Simple Simple Max. diameter Max. thickness 5mm 5mm Flow interruption None During vertical flight Effect on curved outer contour Distinguished step Minimal step

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30 The basic Tri Rotor UAV configuration: Two parallel rotors with opposite rotation Single tilted rotor Tilt angle α enables 3 degrees of freedom motion Force and moment equations:

31 4 motion controls for the model Available by change in α or angular velocity Ω: [1] Dynamic Modeling and Stabilization Techniques for Tri-Rotor Unmanned Aerial Vehicles

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33 Inner loop angular-rate feedback Outer-loop attitude feedback

34 Desired speed Desired altitude Tri-rotor dynamics Flight speed control altimeter Pitot Reaching desired altitude horizontal motor powers up. Reaching desired flight speed vertical motors shut down. Shutters parallel with horizontal motors.

35 Equations for transmission equation. Tunnel test did not yield all the required parameters. Need more experiments.

36 X T Z Y

37 Inertial Sensors: Linear and angular accelerometers. Gyroscopes Air Data Sensors Flow direction (α,β). Flight speed sensor (Pitot) Altimeter Optic sensors, GPS, etc. All Included in our controller Micropilot 2128HELI

38 Basic block diagram for pitch angle control: Ʃ Amp. Elevators control Plane Dynamics Vertical Gyroscope

39 Basic diagram - Automated pilot: Vertical Gyroscope Amp. Elevators Control Plane Dynamics Angular Gyroscope Amp. Rudder Control

40 β control with angle feedback: Rudder Control Plane Dynamics WO Filter Yaw Rate r Gyro. Slip angle sensor

41 α control with lateral acceleration feedback: Rudder Control Plane Dynamics WO Filter Yaw Rate r Gyro. Lateral accelerometer

42 Rudder Control: Ailerons Control Rudder Control Plane Dynamics WO Filter Yaw Rate r Gyro.

43 Basic diagram - Yaw rate control in a coordinated plane: Yaw Rate s RIG Ailerons Control Coordinated Plane Roll Rate p Gyro.

44 Basic diagram - Roll angle control in a coordinated plane: Vertical Gyro Ailerons Control Coordinated Plane Roll Rate Gyro.

45 Directional Gyro Coordinated Plane With Aileron Control Roll Rate p Gyro. Yaw Rate r Gyro.

46 *Reference datum - Payload Station Fuselage Motor V1 Weight [Kg] Arm [m] Moment [Kg*m] MTOW 4.5Kg 39mm Motor V2 Motor V3 Motor H4 Battery 1 Battery Battery Controller Controller Controller Controller EL Servo AL Servo RU Servo RU Servo Tx\Rx Payload.99 Contingency.194

47 Location Center of mass Aerodynamic center Distance from reference datum [mm] 39mm 391.5mm Improving stability margin: Move front motor and hole forward Using control system for non-even power settings for forward and rear motors. Stability margin.3%

48 Wind tunnel limitations: Blockage percentage 4% Scale: 1:2.5 Modification Connection to balancer 3D Printing of the fuselage and wings Split the model into 4 main parts Reinforcement of wing-body connection

49 393mm 297mm D=1mm X3 232mm 484mm 716mm

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52 Calibration run Clean aircraft configuration: Change elevators Change ailerons including split aileron Change rudders Top covers only configuration: Change elevators Change ailerons Change rudders No covers configuration: Change elevators Change ailerons Change rudders

53 Priority Rudders Elevators Ailerons Motor covers Pitch Plane - α range Air speed (m/s) Test No. 1 top+bottom top+bottom top+bottom top+bottom top+bottom top+bottom top+bottom top+bottom top+bottom optimal speed top+bottom top+bottom top+bottom top+bottom split aileron top+bottom top only top only top only top only top only top only optimal speed top only top only top only top only split aileron top only

54 none none none none none none optimal speed none none none none split aileron none Preference Rudders Elevators Ailerons Motor covers Yaw Plane - β range Air speed (m/s) Test No. 1 1 split aileron top+bottom top+bottom optimal speed top+bottom top+bottom top+bottom optimal speed top+bottom top only top only top only optimal speed top only none none none optimal speed none

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59 New (L/D)max=26.14:

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62 Drag increases Side force increases Lower lift for splitter Similar roll Similar yaw Using the splitter ailerons leaded to similar yaw, with great loses. The conclusion- during the actual flight, the rudders will be in use.

63 All shutters open Two bottom back shutters open All shutters closed All bottom shutters open Only upper front shutter closed

64 All shutters closed Two bottom back shutters open All bottom shutters open Only upper front shutter closed All shutters open

65 As expected, the drag increases when more shutters are open All shutters closed Two bottom back shutters open No significant change- side forces are low All bottom shutters open Only upper front shutter closed All shutters open Low lift loss for the first 3 options

66 Some of the shutters can stay open during the horizontal flight Two main options: All bottom shutters remains open Only two bottom back shutters open The difference between the two is not significant The option of bottom shutters open was chosen And now: Confirming this choice by: Comparing the configurations at maneuvering Calculating the loses of range and endurance

67 The results showed similar CL with open shutters. The experiment was repeated to verify the results.

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72 The results are similar. Maximum drag for open shutters All shutters closed Two bottom back shutters open No significant change in side force All bottom shutters open All shutters open The lift decreases as the shutters open

73 Shutters closedexpected Shutters closedresults Bottom shutters open- results

74 Shutters closedexpected Shutters closedresults Bottom shutters open- results

75 Analysis results Experimental Results- All Shutters Closed Experimental Results- Bottom Shutters Open Stalling Speed [Kts] Minimum Drag [Kgf] At Speed Of [Kts] Minimum Required Power [Watt] At Speed Of [Kts] Maximum Cruise Range [Km]

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78 Rudders were chosen for yaw control after a comparison to the splitter aileron version. The forces and moments differences of the configurations were examined while changing the angle of attack. The UAV cannot fly without motor covers. Bottom shutters open - the results showed similar lift with greater drag Bottom shutters open will lead to decreasing the UAV s range by 5% (1Km) The aerodynamics mentioned were examined for different maneuvering performances Results were similar Main conclusion- There is no need for bottom covers no need for extra mechanism

79 o Systems/Components Installation Arrangement o Conceptual Design of Wing Structure o Detail Design of Outer Wing Segment o Detail Design of Rotors Cavity Closing Mechanism o Finalize Weight and Balance Analysis o Finalize Aircraft Performance Analysis o Flight Control System Design o Wind tunnel Test and Test Results Evaluation

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81 Prof. Arthur Grunwald Mr. Mark Koifman Mr. Jeffery Mayer Mr. Michael Grossman Mr. Prosper Schoshan Mr. Mordechai Mansour Mr. Marcel Leventer Mr. Zvi Shachar Mr. Dolav Simon And a big thanks to our supervisor: Mr. Dror Artzi

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