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Navigation—A General Overview

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Fig. 13.7 Ring Laser Gyroscope (RLG)

MEMS based gyroscopes contain vibrating elements for measuring Coriolis

effects. Many geometries are existing with vibrating elements. The simplest geom-

etry consists of a single mass, and vibrates along a driven axis. Secondary vibration

is generated along the perpendicular spin axis, when the gyroscope is rotated. With

this secondary rotation, angular velocity can be calculated.

The accuracy of MEMS sensors do not match with the accuracy of optical devices.

The advantages of MEMS inertial sensors are as follows:

• Less power consumption

• Rugged structure

• Small size and Low weight

• Small start-up time

• Low cost

• High reliability

• Less maintenance Compatible

Themaindrawbackof INSis thedeteriorationof accuracywithtime. Theaccuracy

depends on the type and quality of IMUs used for navigation.