Gyroscope

GYROSCOPE

Definition

A gyroscope is a device used for measuring or mahntaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rotation (spin axis) is free to assume any orientation by itself.

When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum

Gyroscopic principle

All spinning objects have gyroscopic properties. The main properties that an object can experience in any gyroscopic motion are rigidity in space and precession.

Description and working

A gyroscope is essentially a heavy wheel rotating at a high speed about an axle passing through its centre of mass and so mounted as to be free to turn about any of the three mutually perpendicular axes 1, 2, 3 (Fig.1.44 (a) & (b)).

If the wheel rotates with high angular speed about the axis 1, the base may be turned in any manner without exerting any torque on the wheel.

In other words, as long as the wheel rotates rapidly, it maintain its axis of rotation unchanged in space as the support is tilted in any manner.

If, any torque is applied perpendicular to the axis of rotation, there will be a precession inversely proportional to the angular momentum (I ω) of the wheel However, a heavy wheel rotating at high speed, having a large moment of inertia, would suffer very small precession.

Thus gyroscope is a device characterised by the greater stability of its axis of rotation.)

Applications

1. In view of the property of stability, the gyroscopel is used as stabilizers in ships, boats and aeroplanes. 

2. Due to the inherent stability of the gyroscope it is used was a compass, and a gyro-compass is preferable to the magnetic compass in many respects. 

3. Another important application of the directional stability of a rapidly spinning (rotating) body is the Titling of the barrels of the rifles. 

This spin motion prevents the deflection of the bullet from its path due to air and gravity effects, and causes only very little precession. Thus the uniformity of flight of the bullet is increased. 

4. The rolling of hoops and the riding of bicycles (which are statically unstable since both of them cannot Fremain in equilibrium when at rest) are possible because of the gyroscopic effect. This effect produces a movement of the plane of rotation, tending to counterbalance the disturbing action of gravity.

5. Many modern aircraft instruments such as automatic pilot, bomb sights, artificial horizon, turn and back indicators, etc. have been developed on gyroscope controlled principles.