MICRO AIR VEHICLES

WHAT ARE MAVS(  AV’S)? Multi functional, militarily capable, small flight vehicles. size should be less than15cms. Reynolds's no < 10^5. For a Primarily intended and developed for defence applications.

WHY MAV’S? WHY NOT SOMETHING BIGGER?  Keeps security personnel out of harms by providing situational awareness right down to platoon level.  Direct connectivity  Can be individually controlled  Can be used for a wide range of new missions _ (even unthought-of before  )

APPLICATIONS  Reconnaissance  Surveillance  Defence applications  Weather forecast  Wildlife study &photography  Crowd control  Targeting  Border surveillance  Traffic monitoring  Tracking criminals & illegal activities  Biochemical sensing  inspection of pipes

OVER THE HILL RECONNAISSANCE

MOTHER BIRD APPROACH

Tracking of chemicals

MAIN SUB SYSTEMS 1. FLIGHT CONTROL 2. PROPULSION SYSTEM 3. COMMUNICATION SYSTEM 4. GUIDANCE&NAVIGATION

MAV flight regime compared with existing flight vehicles

FLIGHT CONTROL&AERODYNAMICS  Reynolds's no:= inertia force/viscous force  Low Reynolds's no: flights may have lift to drag ratio of 5 to 10.  The best aspect ratios usually lie between 1&2  Angle of attack should be 5-12° for good endurance.  If angle of attack <5, low aerodynamic efficiency  Endurance=  /power requirement  For optimal endurance the mav should fly at7°

ACTIVE OR PASSIVE CONTROL  Use strategies using MEMS  Create &install tiny sensors  miniature actuators  Flow character controlled by sensor arrays  Flexible membranes or micro flaps to affect the flow as required  Micro motors piezoelectric devices magneto elastic ribbons

WING DESIGN AND FABRICATION  Types of wings  wing shapes  Composite materials,  Carbon fibres  carbon fibre-balsawood sand witches are commonly used

Inflatable wing  Distend (fill) with air or gas  Application in UAV, military  To stow the wings  Can be launched from gun or aircraft

Advantages of aircrafts with inflatable wings  Can be packed to 1/10 of original size  Low mass  Low power requirements  High reusability  It can be steered, accelerated, and decelerated in level flight.  High stability and control  High lift and slow landing speed

Experiment on inflatable wing  Experiment conducted using I 2000  It was launched from feet  Inflatable wings comes out in 1\3 sec  Successfully controlled the launch,flight and landing

Controlling of wing by using piezoelectric material  by using piezoelectric material

 actuator can be quartz and substrate can be aluminum or steel  inflatable wings has smooth surface so low value of skin friction

I-2000 & X-24A  Both have inflatable wing  I-2000 is UAV  X-24A is manned

Disadvantages  They are not self powered  Cannot launch from ground  There are chances of air bag buckling

PROPULSION SYSTEM  Propulsion system alone consumes 90% of total power  Lithium alkaline batteries  IC engines  Reciprocating chemical muscle  Lithium battery that recharges using solar energy and fuel cells are also future prospects  Self consuming systems

COMMUNICATION SYSTEM  A video/still camera,  various sensors,  micro processors,  Transducers  & an omni directional antennae

GUIDANCE AND NAVIGATION  A combination of GPS+inertial sensing is ideal  Geographical information system to provide a map terrain for infrastructure would be great  Pressure sensors

MAV SYSTEM INTEGRATION