MICRO AIR VEHICLES(MAVs) WITH FLAPPING WINGS GUIDED BY: A ASHFAK Sreejath S M7A 7149

What are Micro Air Vehicles? A Micro Air Vehicle (MAV), or micro aerial vehicle, is a class of unmanned vehicles (UAV). DARPA(Defense Advanced Research Project Agency) defines- less than 6 inch(15cm) and 4 ounce weight. Semi-autonomous. Remote observation of hazardous environments. Military capability and Fully-functional. Lift for flight is made with rotary wings and flapping wings. 1

Missions of MAV Military Surveillance, Reconnaissance,tagging,targetting Biochemical sensing. Urban Surveillance,Hostage rescue, Border patrol Commercial Traffic monitoring Fire & rescue Forestry& wild life survey Real-estate photography 2

Over-the-hill reconnaissance mission Chemical contamination monitoring Urban operations missions 3

MAV REQUIREMENTS Based on the missions, an MAV require: High image resolution. Lightweight. Affordable. Secret/hidden. Safe & simple to operate. Easy to repair. Rapid electronic connectivity. 4

SHAPE OF MAVs Fixed wing aircraft- Names like“Trocoid”, “Micro STAR”, “Flyswatter”, “MITE”, “Batplane”, “Wasp” Rotary wing aircraft- “Micro Craft iSTAR”, “Gyrosaucer”,“Helirocket”, and “MICOR” Flapping wing air craft-“Entomopher” and “Microbat”. The Wasp Micro Craft iSTAR The Microbat 5

COMPARISON WITH OTHER AIR VEHICLES 6

Low Reynolds number(<10^5). Traditional UAVs-high Reynolds number aerodynamics. Classical aerodynamics do not obey. Continuous variation in wing orientationUnsteady aerodynamics. Low thrust & lift. Limited weight & payload capacity. 7

DESIGN ASPECTS Must remain within the line of sight of a small base station. Beyond the line of sightautonomous navigation. Navigations such as dead reckoning, inertial navigation, and the Global Positioning System (GPS) can be used. 8

MATERIALS USED FOR AIRFRAME CONSTRUCTION Balsa wood Foam polystyrene Foam with a single layer of epoxy fiberglass coating. Carbon Fiber Composite (Kevlar or Fiberglass) 9

Electrical Components of MAVs Airframe Actuators Sensors Communication Transmitter Receiver Antenna Microprocessor Sensors Acoustic sensor Optical sensor 10

MAV flight-control system 11

PROPULSION Electric motors + batteries or fuel cells. IC engines. Compressed gas. Flywheels or capacitors for energy storage. Power= 𝑚 𝜂 𝑚 𝑆 1 2 2 𝜌 1 2 𝐶 𝐷 𝐶 𝐿 3 2 Endurance=f 1 Power 12

FLAPPING WING AND ITS FEATURES Lift is generated in two ways, (1) Air flow created by the vehicle speed. (2) Wing flapping. Ability to perform short take offs and landings. Can take off and land vertically. Reduced sizeincreased beating. 13

Equal & opposite circulation causes lift. Kelvin’s circulation theorem, the net circulation around the insect body is zero. Equal & opposite circulation causes lift. Ordinary insects, this build-up of high lift coefficient is delayed. One species of insects, Encarsia Formosa, which avoid any delay in built up of maximum lift. 14

WIES FOGH’S 2-D MODEL Based on the insect,Encarsia Formosa. Clap-wings come together at the end of upstroke. Fling-trailing edges of the wings stay connected. Clap is not performed by all insects. Clap increases lift 15

FLAPPING MECHANISM Flapping wing mechanism: Direct actuation Actuation with mechanism(4 bar linkage) Combination with torsional spring 16

ADVANTAGES Less size& weight. Low power requirements. High reusability. Speed 10-15 m/sec, not detected by most Radars. High stability and control. High lift and slow landing speed. Can be individually controlled. Wide range of new missions. 17

DISADVANTAGES Low image quality due to blurring. Small range of communication. Very difficult to design flapping wing mechanism. Very difficult to control MAVs in bad weather. Very expensive to design MAVs. Lithium batteries are expensive, compared to the common alkaline batteries. 18

FUTURE WORK Mechanism that simulates Wies Fogh’s model. Use lighter materials, for the frame of MAV,the controllers, the gyroscope for stabilizing. Developing small power sources. Designs to achieve high flight speeds better stability in air. The overall aim will be to minimize the size and weight, to increase the speed, and to maximize the battery life for MAV. 19

CONCLUSIONS Time of MAVs have arrived. Micro Air Vehicles are the new technology by which a variety of operations are done. Flapping mechanism have more lift compared to fixed wing mechanism. Also it can increase the lift without increasing the vehicle speed. Simple flapping, does not generate sufficient lift. In the seminar, we have tried to highlight the recent research and development in establishing a flexible-wing-based technology for MAVs. 20

REFERENCES Mohd. Shariff Ammoo, Md. Nizam Dahalan,”Micro Air Vehicle: Technology Review and Design Study, Department of Aeronautic & Automotive”, Faculty of Mechanical Engineering, University Technology, Malaysia. Mr. T. Spoerry1, Dr K.C. Wong, “Design and Development Of A Micro Air Vehicle: Project Bidule” School of Aerospace, Mechanical and Mechatronic Engineering University of Sydney NSW 2006. Peter G. Ifju, Scott- Ettinger, David Jenkins, and Luis Martinez, “Composite materials for micro air vehicles”, Aerospace Engineering, Mechanics and Engineering Science Department University of Florida, Gainesville. Huaiyu Wu, Dong Sun, and Zhaoying Zhou, “Micro Air Vehicle: Configuration, Analysis, Fabrication, and Test”. Atilla Yilmaz, ”Design and Development of a Flapping Wing Micro Air Vehicle": Swiss Federal institute of tehnology,zurich, Oct 2009 - Apr 2010. William R. Davis, Jr., Bernard B. Kosicki, Don M. Boroson, and Daniel F. Kostishack “Micro Air Vehicles for Optical Surveillance”, THE LINCOLN LABORATORY JOURNAL, VOLUME 9, NUMBER 2, 1996. Thomas J. Mueller, “On the Birth of Micro Air Vehicles”, Department of Aerospace and Mechanical Engineering, University of Notre Dame,Notre Dame, Indiana, USA. http://en.wikipedia.org/wiki/Micro_air_vehicle 21

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