Gyroscopic Stabilization

7 min readDec 5, 2022

Gyroscope

A device which has a spinning disc mounted on the base so that it can move freely in more than one direction so that the orientation is maintained irrespective of the movement in the base. A gyroscope is a device that consists of a wheel or disc or circulating beam of light mounted such that it can spin rapidly about an axis; this axis is free to change in any direction. The orientation of the axis is not impacted by the tilting of the mounting, so the gyroscope is in effect used to detect and measure the deviation of an object from its desired orientation, even maintain the said orientation and angular velocity.

Gyroscopic Effect

According to the equation that describes gyroscope behavior, the torque on the gyroscope applied perpendicular to its axis of rotation and also perpendicular to its angular momentum causes it to rotate about an axis perpendicular to both the torque and the angular momentum. This rotational motion is referred to as precession.

Gyroscopic stabilization

Gyroscopic stabilization is a system that is used to control and minimize the tilting movement in an unstable object. The system consists of a gyroscope which senses the tilt and orientation of the body or object. Sensing the tilt of the object the gyroscope gives then a reaction as it counter rotates by adjusting the control surface or by applying force to a gyroscope.

Types of Gyroscope

There are three basic types of gyroscopes which are used by the industry for various applications.

1. Mechanical

The mechanical gyroscope completely depends on mechanical phenomena. The conservation of angular momentum is the basic working principle of the mechanical gyroscope. This type of gyroscope is mostly used in the industry.

2. Optical

A ring laser gyroscope (RLG) consists of a ring laser having two independent counter-propagating resonant modes over the same path; the difference in phase is used to detect rotation. It operates on the principle of the Sagnac effect which shifts the nulls of the internal standing wave pattern in response to angular rotation. Interference between the counter-propagating beams, observed externally, results in motion of the standing wave pattern, and thus indicates rotation.

3. Gas — Bearing

In gas-bearing gyroscopes the rotor is suspended by pressurized gas, reducing the amount of friction between moving parts. These types of gyroscopes were used by the NASA in the development of the Hubble Telescope. According to NASA, the gas-bearing gyroscopes are much quieter than other forms of gyroscopes and also have greater accuracy. In fact, NASA states the gyroscopes aboard the Hubble Telescope are among the most accurate in the world.

Application of gyroscopic stabilization

1. Boats

To avoid the boat from rolling the gyroscope itself moves front and back.

When the gyroscope is unlocked, it rotates with a high rpm thus creating a high angular momentum in upward direction. Whereas the wave hitting the boat provides Torque which is directed into the screen(away from us), giving an angular impulse which changes the gyroscope’s position by a small amount.

As the gyroscope had high angular momentum , it required a high amount of Torque to change its orientation, thereby the Gyroscope provided a large counter Torque to stabilize the boat from rolling from side to side.

2. Heading Indicator

Gyros are also used in case of heading indicators which are devices used to inform the pilot of the aircraft’s heading. The gyroscope is tied by and erection mechanism to the aircraft yawing plane, so any configuration of the aircraft yawing plane that does not match the local Earth horizontal results in an indication error. The heading indicators gyroscope is arranged to drive the display which consists of a circular compass card calibration in degrees. The gyroscope can be spun either electrically or by using filtered air flow from a suction pump driven from aircrafts engine. The heading indicators tend to drift over time due to the earth’s rotation and the small accumulated errors caused by imperfect balancing of the gyroscope, and therefore needs to be reset using a magnetic compass periodically. The apparent drift can be predicted using ωsin(Latitude) therefore will be maximum at the poles. A latitude nut is set to induce a real wander in the gyroscope.

A Gyro compass is a form of gyroscope, used widely on ships employing an electrically powered, fast-spinning gyroscope wheel and frictional forces among other factors utilizing the basic physical laws, influences of gravity and the Earth’s rotation to find the true north.

3. Gyro Compass

4. Mobile

In mobile phones gyroscope is used to detect motion and gestures with our phones. Smartphones usually use the electronic version of the vibration Gyroscope sensor. In mobile phones, it is used for playing high-technology AR game.

5. Inertial Navigation System

An inertial navigation system (INS) is a navigation device that uses motion sensors (accelerometers), rotation sensors (gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references. Often the inertial sensors are supplemented by a barometric altimeter and sometimes by magnetic sensors (magnetometers) and/or speed measuring devices. INSs are used on mobile robots and on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft. Other terms used to refer to inertial navigation systems or closely related devices include inertial guidance system, inertial instrument, inertial measurement unit (IMU) and many other variations. Older INS systems generally used an inertial platform as their mounting point to the vehicle and the terms are sometimes considered synonymous.

6. Rifling

In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun’s barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs.

The combination of length, weight, and shape of a projectile determines the twist rate needed to gyroscopically stabilize it — barrels intended for short, large-diameter projectiles such as spherical lead balls require a very low twist rate, such as 1 turn in 48 inches (122 cm). Barrels intended for long, small-diameter projectiles, such as the ultra-low-drag 80-grain 0.223 inch bullets (5.2 g, 5.56 mm), use twist rates of 1 turn in 8 inches (20 cm) or faster.

7. Aerospace (Control Moment Gyroscope)

A control moment gyroscope (CMG) is an attitude control device generally used in spacecraft attitude control systems. A CMG consists of a spinning rotor and one or more motorized gimbals that tilt the rotor’s angular momentum. As the rotor tilts, the changing angular momentum causes a gyroscopic torque that rotates the spacecraft.

CMGs differ from reaction wheels. The latter apply torque simply by changing rotor spin speed, but the former tilt the rotor’s spin axis without necessarily changing its spin speed. CMGs are also far more power efficient. For a few hundred watts and about 100 kg of mass, large CMGs have produced thousands of newton meters of torque. A reaction wheel of similar capability would require megawatts of power.

8. Microelectromechanical Gyros

In a spacecraft, gyroscopes tell the onboard computer when the craft has changed its attitude (direction and pointing). The computer then sends the information to the spacecraft’s stabilization device, which can make corrections. In recent years other types of gyros have been used in spacecraft: laser ring gyros, hemispherical resonator gyros, and microelectromechanical system (MEMS) gyros — — the type Space Technology 6 (ST6) will use. MEMS are a combination of tiny electrical and mechanical devices etched in silicon much like computer chips.

Compass uses a MEMS 3-axis assembly that incoporates “tuning fork” gyro sensors and mixed signal application-specific integrated circuits (ASIC). These gyro electronics are designed to operate with approximately 12 off-chip components at a power draw of 75mWatts.

The Compass MEMS assembly includes data acquisition electronics that will provide angular rate, temperature, and health and status data to the processor. These components are small in volume, mass, and have high resistance to radiation and vibration.

Together, the Compass gyroscopes and star camera keep the spacecraft stable and oriented in the right direction in space.