The Gyroscope and its applications

What is a Gyroscope?

The gyroscope the name is derived from two Greek words “gyros” which means “turn” or revolution and “skopein” which means “view.”. The above derivatives say the meaning of a gyroscope is “to view the turning”.

Encyclopaedia Britannica defines the “gyroscope – device containing a rapidly spinning wheel or circulating beam of light that is used to detect the deviation of an object from its derived orientation” Offline Dictionary of English says gyroscope that-“an apparatus composed of a wheel which spins inside of a frame (gimbal) and causes the balancing of the frame in any direction or position”

Now we may conclude that the gyroscope is a device based on precession motion. It has a rotor a freely spinning disk with an axle installed on the gimbal(which is fixed to a massive strong frame structure) and can navigate in three directions of the space, to maintain the orientation, irrespective of any directional movement of the base.

The invention of the device:

The gyroscope was first devised by one German Scientist Johann Bohnenberger, in the year 1817 AD and named as “Machine”. However, the term “gyroscope” was coined by French experimental Physicist Leon Foucault in 1856 and demonstrated the rotation of the earth with the gyroscope.

Parts of a gyroscope and mechanism:

A traditional gyroscope contains basically four parts excluding the base as follows;

• _{Gyroscope frame.}
• _Gimbal.
• _Rotor.
• _{Spin axle/axis.}

The gyroscope device works on precession motion or spinning top theory. In the gyro, a wheel or the rotor is fixed at a specific angle so that the rest of the device is free to revolve around the axis without any resistance. In fact, as long as the spin keeps rotating, it keeps the gravitational force at bay. The higher the spinning motion longer the resistance to gravitational force. Here torque causes the rotation of the wheel, where torque is equal to the rate of change of angular momentum.

The torque about the pivot point induces the angular momentum to change

Ԏ=dL/dt  (Ԏ=torque)(L=angular momentum)

bmg=IL^spin_cmIΩ

F_vertical-mg=0

F_rad=-mbΩ²

Types of gyroscopes:

Gyroscopes are classified into different types on the basis of their design and technology employed, such as-

Mechanical gyroscope:

It is the most common type of gyroscope that works on the principles of conservation of angular momentum and the basic principles that apply to it. A gyroscope is used in navigation systems. As an ordinary compass depends upon the magnetic field of Earth and it may differ at different locations of the Earth and reading near the north and south poles is misleading.

Gyroscopes replace or complement the traditional compass, as it is not bound by the magnetic field of Earth. Ships and submarines use big marine as well as other types of gyroscopes for safe navigation in troubled seas. The air crafts may have used many gyroscopes but the most important is the directional gyroscope/ heading indicator and another vertically mounted gyroscope known as the artificial horizon.

In autopilot systems, many gyroscopes are used including the above two and the turn coordinator. Gyrostabilizer is another type of gyro used in ships to resist rolling movement and keep the ships steady. The marine gyro was first made in Germany in the year 1908 and subsequently, it was further developed in subsequent years.

Micro Electro Mechanical System(MEMS): MEMS is a type of mechanical gyroscope, where the motion sensors are capable enough to detect and measure the angular velocity of an object. Such systems developed in the late 20th century.

Optical gyroscope:

Optical gyroscopes use optical fiber cables for operations and do not depend upon angular momentum. A fiber-optic gyroscope(FOG) works on the principles of interference of light. Optical fiber carries pulses of laser light and is split by a half-silvered mirror into two beams, where some pulses move clockwise and others anticlockwise(other direction).

It is referred Sagnac effect, where senses change in orientation, making it works like mechanical gyroscopes. Here rotation is measured by pulses arrived in the sensor. Ring laser gyroscopes(RLG) also work on the same principles of the Sagnac effect or Sagnac interference named after scientist George Sagnac of France.

Gas-bearing Gyroscope:

Gas-bearing gyroscopes are also referred to as fluid film-bearing or air-bearing gyroscopes. Such types of gyros are the most reliable, long durable, accurate, and with low mechanical noise. The rotor is suspended by pressurized gas which is the cause of low noise. NASA uses the applications of such types of gyroscopes in Hubble Telescopes and is extremely useful in space crafts.

Applications:

Gyroscopes are essential devices for aviation, spaceships, missile technology, mining, and many more. Such as-

• _{So many compasses used in ships, space crafts, and autopilots employed gyroscopes.}
• _{Big ships, submarines, and satellites were mounted with giant gyroscopes to give stability to the units.}
• _{Gyroscope sensors are finds their place in smartphones.}
• _{Dynamically Tuned Gyro(DTG) or Tuned Rotor Gyro finds its applications in the drilling field and borehole gyro survey tools.}
• _{In tunnel mining gyroscopes are extremely useful.}
• _{All most all modern fighter jets and commercial flights use RLG applications such as; AirbusA320, Boeing 757-200, F-15E Strike Eagle, F-16 Fighter Falcon, HAL Tejas, Sukhoi Su-30MKI, JF-17 Thunder, etc.}
• _{International Space Station and Inter-National Navigation Systems have gyroscopic applications.}
• _{Most of the missile systems have TLG technology. Some of the examples are DRDO,(India) developed Agni series(Three, four, five).}

Conclusion:

Gyroscopes come a long way since their origin in the early 19th and their original use in navigation still remains its principal objective. Gyroscopes are modernized with laser technology and the Sagnac effect which gives accurate reading and direction.

Gyroscope applications are now localized and find their place in very familiar handsets like smartphones. Most advanced fighter jets, missile systems, and spaceships use gyroscope systems in the most sophisticated manner for the best possible output.