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accelerometers and tilt sensors are transported to automobile industry and various

consumer products every year. Several advantages of these products are given below:

• Immune to vibrations—no measurable resonance

• Virtually indestructible (Very high shock tolerance capacity ≈50,000 g)

• Hysteresis are undetectable

• No friction

• Excellent zero-g offset stability

• Sensor and electronics integrated onto monolithic IC.

At present, most of the MEMS based gyros and accelerometers with different

specifications are available with Analog Devices Inc (ADI). To manufacture and

reach the ultimate goal of navigation for MAVs with micro fabricated MEMS, may

need to face many challenges. Reliability of MEMS in these applications is to be

assessed with temperature burning, G test, vibration tests and other aerodynamic

considerations. These tests vary from wafer to wafer, batch to batch and sometimes

rely on product.

A top-down approach can be followed to replace the bulky and heavy components

by MEMS, but bottom-up approach is needed to apply MEMS based navigational

systems at various superior platforms. The successful integration of MEMS with

other navigation devices will address the challenges by the double-oriented approach.

It guarantees the successful navigation in MAVs.

Primary navigation is done by GNSS, and as and when GNSS is not available or

in the emergency, MEMS bases inertial navigation will be used. Of course navigation

will be available in all weather conditions by integration of GNSS with MEMS based

IMU sensors.

Integrated GNSS and MEMS based navigation with single chip for affordable

cost, light weight and size, is very well suitable for MAVs for Accurate and reliable

navigation.

Summary

Various navigation methods used by Human being in olden days and present days

are described. Nowadays MEMS based Inertial Sensors, Global Navigation Satellite

Systems, Radar, ILS/MLS, Vision and LIDAR are used for navigation. All the above

mentioned methods are elucidated one by one.

• Inertial sensors are independent systems which give position, velocity and atti-

tude of moving vehicles, used for ships, aircrafts, space crafts and land vehicle

applications. Increase in errors with time is the main limitation for INS.

• GNSS is a satellite based positioning systems, and many users are using GNSS

for military purpose, transportation, mapping etc. Only useful in the outdoor

environment. Ionosphere, atmosphere and interference like jamming and spoofing