The Institution of Engineering and Technology Seminar on. Micro UAVs. Dr Tom Richardson University of Bristol. 20 th February 2007

Transcription

1 The Institution of Engineering and Technology Seminar on Micro UAVs Dr Tom Richardson University of Bristol 20 th February 2007

2 Contact Information Address: Dr Tom Richardson Department of Aerospace Engineering Queens Building University Walk University of Bristol, BS8 1TR

3 MAV presentation - Contents Past MAV Definition Fixed, Flapping and Rotary Wing Commercial and Academic Development Present University of Bristol Fixed Wing Flapping Wing Future Competitions Key areas for development Limits to MAV development?

4 Past MAV Definition Fixed, Flapping and Rotary Wing Commercial and Academic Development

5 What is an MAV? UAV Unmanned or Uninhabited Air Vehicle UAS Unmanned Aircraft Systems MAV Micro Air Vehicle Micro!? Micro Air Vehicles - Toward a New Dimension in Flight 1997 (1) DARPA - Defence Advanced Research Projects Agency James M. McMichael, Program Manager DARPA, and Colonel Michael S. Francis, USAF (Ret.) formerly of Defense Airborne Reconnaissance Office MAV definition The definition employed in DARPA's program limits these craft to a size less than 15 cm (about 6 inches) in length, width or height.

6 Initial DARPA MAV Definitions from (1) MAVs are affordable, fully functional, militarily capable, small flight vehicles in a class of their own. MAVs can deploy a useful micro payload to a remote or otherwise hazardous location MAVs may perform any of a variety of missions, including reconnaissance and surveillance, targeting, tagging and biochemical sensing. Although the 15 cm limitation may appear somewhat arbitrary, it derives from both physics and technology considerations. The low Reynolds number regime is significant in that it projects a fundamental shift in physical behavior at MAV scales and speeds - an environment more common to the smallest birds and the largest insects.

7 Initial DARPA MAV Requirements from (1) The technology challenge to develop and integrate all the physical elements and components necessary to sustain this new dimension in flight will require an unprecedented level of multifunctionality among the system components. The MAV must trade favorably with other soldier assets - like water and ammunition. The system must also be affordable. For many missions it must be intrinsically covert.

8 MAV Requirements? 1st US-European MAV Competition September 2005 held in Germany: Limits Desired System mass < 500 g 150 g Maximum dimension < 500 mm 250 mm Endurance > 10 min 30 min Range > 0.5 km Noise level at 15m < 60 db 3rd US-European MAV Competition - MAV 07 ( Two challenging missions will be open to MAVs of which the maximum dimension is 500 mm and maximum weight is 500 grams. Technology Demonstrations open to mini-uavs under 1 meter and 2 kilograms will allow to demonstrate novel, cutting-edge technologies as applied to indoor and outdoor MAVs.

9 Fixed Wing University of Bristol fixed wing MAV Span of 350mm Root chord of 200mm Overall Mass of 267g Brushless Electric motor

10 Flapping Wing University of Bristol flapping wing MAV Bio-inspired MAV design Parallel crank-rocker (PCR) mechanism Professor Stuart Burgess Mechanical Engineering, UoB

11 Rotary Wing The 60 mm rotor diameter Picoflyer is the smallest RC helicopter The Picoflyer had it's first flight on the 7 th August Petter Muren

12 Commercial MAV AeroVironment Early AeroVironment Prototype Growing interest in the early 1990s DARPA funded in 1996, AeroVironment performed a Phase I study, which concluded that a sixinch MAV was feasible In the spring of 1998, AeroVironment was awarded a Phase II SBIR contract, which resulted in Black Widow MAV AIAA Development of the Black Widow Micro Air Vehicle Joel M. Grasmeyer and Matthew T. Keennon

13 Commercial MAV AeroVironment Black Widow 4 year project 6-inch span (15cm), fixed-wing aircraft Flight speed of 30 mph Endurance of 30 minutes Communications range of 2 km The Black Widow featured an autopilot with altitude hold, airspeed hold, heading hold, and yaw damping. Electronic subsystems include a 2-gram camera, a 2-gram video downlink transmitter, and a 5-gram fully proportional radio control system with 0.5-gram actuators. Multidisciplinary Design Optimization with Genetic Algorithms

14 Commercial MAV AeroVironment Wasp Span of 41 cm 275 grams The Wasp is AeroVironment's smallest UAS. Wasp can be manually operated or programmed for GPS-based autonomous navigation. Entered Service with the US Marines 2005 / 2006 Forward- and Side-Look EO Cameras Range 2 km to 4 km Line-of-Sight Speed km/h Operating Altitude 50-1,000 ft AGL

15 Academic involvement with MAVs Brigham Young University s MAGICC Lab was placed first in the MAV competition held at Eglin Air Force Base in Florida on October 28-31, 2006 Fully Autonomous BYU was able to see all three targets and positively identified two. Kestrel autopilot (KAP) grams Three-axis rate gyros and accelerometers for attitude estimation Autonomous Takeoff and Landing modes Multiple air vehicle support Autonomous Modes: Home, Loiter, Rally, Waypoint Navigation

16 Present University of Bristol Fixed Wing Flapping Wing

17 University of Bristol -MAV Tailored towards the US- European MAV Competitions Research elements from final year student projects COTS components Inverse Zimmerman planform t/c 28.13%c C M ¼ camber 37.44%c dc L /dα 0.1 C Lα stall incidence ~12 MH-64 aerofoil

18 University of Bristol -MAV Click! Wind tunnel testing Lift & Drag measurements Flow Visualisation

19 University of Bristol -MAV Second MAV design CAD / CAM Rohacell foam Density 31 kg m -3 Autodesk Inventor Integral Avionics Bay Fibreglass covered Trailing edge control surfaces

20 University of Bristol -MAV Propeller Motor Motor Controller Power Cell GPS GUMSTIX Power Cell Servo Receiver Linkages

21 University of Bristol MAV Mass Breakdown Component Mass (g) Body 75 Linkage mechanisms 5 Servos 10 Airframe 90 (34%) Motor 44 Speed controller 14 Propeller 5 Propulsion 63 (24%) Lithium polymer cells 36 Power 36 (13%) GPS (integrated aerial) 16 Infra-red horizon sensor 9 Receiver 9 Gumstix 12 Robostix 17 Harnesses and switches 15 Control system 78 (29%) TOTAL 267

22 University of Bristol -MAV 1.2 c C L Flight Test Model Span 350mm C D Tunnel Test Model Span 300mm Inverse Zimmerman Profile Flat Plate Span 350mm

23 University of Bristol -MAV MAV Configuration Aspect Ratio Cruise L/D Cambered circular plate Inverse Zimmerman plate Tunnel Model Flight Model EasyStar Test bed Elevator + Rudder

24 University of Bristol MAV Control Gumstix running Linux 64mb MMC card FMA copilot GPS receiver

25 LiPo Batteries Receiver Brushless Motor Motor Controller GPS receiver Servos Gumstix Robostix

26 University of Bristol -MAV Google Earth used to display aircraft trajectory NMEA to KML Post flight processing

27 Future Competitions Key areas for development Limits to MAV development?

28 MAV competitions This year sees the: 3rd US-European Competition and Workshop on Micro Air Vehicles 7th European Micro Air vehicle Conference and Flight Competition 2006 saw the: Tenth Annual Micro Air Vehicles Competition (US) Etc

29 Competitions -

30 Competitions -

31 Research Areas: Short Term Sensors continue to reduce the mass and size of sensors, e.g. GPS, E/O, Chemical Autonomy Deconfliction & Route Planning Multiple MAVs providing continuous coverage Endurance - available power, aerodynamics, structures V 2 Human factors & interface A R 2 2 MAV 2 Remaining Distance to B φ R2 O φ R1 R 1 V 1 1 B MAV 1 Remaining Distance to A

32 Research Areas: Medium Term Image stabilisation computer & physical Autonomy e.g. onboard rerouting, mapping Modern Control Systems e.g. Adaptive Control Video reduce bandwidth Gust tolerance Wing warping Delivery of payloads Civilian use vs Military

33 Research Areas: Long Term Perch and stare Ability to loiter behind enemy lines Energy scavenging, e.g. power lines Autonomy and navigation Alternative control motivators Flapping wing MAVs Available onboard computing power will continue increase dramatically offering much greater opportunities for onboard sensor processing, autonomy and control Alternative planforms and structures will be continue to be considered with a drive towards improved aerodynamic performance and reduced gust sensitivity

34 Are there limits to MAV development? e.g. Hypothetical set of Requirements Range of 20,000 km + Span of less than 90 cm Less than 150g Energy scavenging Operational for 10 years Autonomous navigation Realistic?

35 Arctic Tern Arctic Tern! cm long cm wingspan g Life span up to and in some cases over 20 years Longest migration of any bird 20,000 km + One Arctic Tern ringed as an unfledged chick on the Farne Islands, Northumberland, UK in summer 1982, reached Melbourne, Australia in October 1982, a sea journey of over 22,000 km (14,000 mi) in just three months from fledging Wikipedia!

36 Any Questions?