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 800-1000 feet

Inflatable wings comes out in 1\3 sec

Successfully controlled the launch,flight and landing

Controlling of wing

by using piezoelectric by using piezoelectric materialmaterial

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