GYROSCOPES

GYROSCOPES

1. Introduction

Gyroscopes are devices that is used to measure or maintain rotational motion and it is used primarily for navigation and measurement of angular velocity. Gyroscopes senses the changes in orientation and therefore augment motion. Any motion will produce a potential difference from which angular velocity is sensed and this angular velocity is converted into an electrical signal output.Gyroscopes are widely used in Avionics and robotics and defence.  

1. Introduction

2.Types of Gyroscopes

3. Applications for Gyroscopes

4.Working of Gyroscopes

5.Specifications for Selection of Gyroscope

6. Gyroscope Control Methods 

2. Types of Gyroscopes

Gyroscopes have evolved from mechanical-inertial spinning devices consisting of rotors, axles, and gimbals to various incarnations of electronic and optical devices. Each exploits some physical property of the system allowing it to detect rotational velocity about some axis.

There are three basic types of gyroscope:

• Rotary (classical) gyroscopes
• Vibrating Structure Gyroscope
• Optical Gyroscopes

1. Rotary Gyroscopes

Rotary gyroscopes typically consist  spinning disk or mass on an axle, which is mounted on a series of gimbals. Each gimbals offers the spinning disk an additional degree of rotational freedom. The gimbals allow the rotor to spin without applying any net external torque on the gyroscope. Thus as long as the gyroscope is spinning, it will maintain a constant orientation. When external torques or rotations about a given axis are present in these devices, orientation can be maintained and measurement of angular velocity can be measured due to the phenomenon of recession.

2 Vibrating Structure Gyroscope

A vibrating structure gyroscope, standardised by IEEE a Coriolis vibratory gyroscope (CVG), is a wide group of gyroscope using solid-state resonators of different shapes. The underlying physical principle is that a vibrating object tends to continue vibrating in the same plane as its support rotates. In the engineering literature, this type of device is also known as a Coriolis vibratory gyro because as the plane of oscillation is rotated, the response detected by the transducer results from the Coriolis term in it sequations of motion

Vibrating structure gyroscopes are simpler and cheaper than conventional rotating gyroscopes of similar accuracy. Miniature devices using this principle are a relatively inexpensive type of attitude indicator.

3 Optical Gyroscopes

An optical gyroscope senses changes in orientation, thus performing the function of a mechanical gyroscope. However its principle of operation is instead based on the interference of light which has passed through a coil of optical fibre which can be as long as 5 km.

A optical gyroscope provides extremely precise rotational rate information, in part because of its lack of cross-axis sensitivity to vibration, acceleration, and shock. Unlike the classic spinning-mass gyroscope, the FOG has no moving parts and doesn't rely on inertial resistance to movement. Hence, this is perhaps the most reliable alternative to the mechanical gyroscope. Because of their intrinsic reliability, optical gyros are used for high performance space applications.