{{More footnotes needed, date=September 2023 A Rate integrating gyroscope is a rate gyro with a built in

integrator An integrator in measurement and control applications is an element whose output signal is the time integral of its input signal. It accumulates the input quantity over a defined time to produce a representative output. Integration is an importan ...

. It is usually a component of an

Inertial Measurement Unit An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the Orientation (geometry), orientation of the body, using a combination of accelerometers, gyroscopes, an ...

or a stabilization system.

Principle of operation

In a rate integrating gyroscope, the

gyroscope A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining Orientation (geometry), orientation and angular velocity. It is a spinning wheel or disc in ...

is turned at a steady rate about its input axis and a torque is applied to the spin axis. This causes the gyroscope to

precess Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In ot ...

about the output axis. The rate indicating gyroscope consists of a

damping In physical systems, damping is the loss of energy of an oscillating system by dissipation. Damping is an influence within or upon an oscillatory system that has the effect of reducing or preventing its oscillation. Examples of damping include ...

fluid between the float assembly can and the outer casing. This

viscous Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup h ...

fluid resists the motion of the

gimbal A gimbal is a pivoted support that permits rotation of an object about an axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of ...

precession. This causes the gimbal to accelerate initially in the fluid, until the damping effect is equal to the precessing force. The rate of precession, will hence be directly proportional to the rate of turn of the gyroscope about its input axis and the total angle of movement about the output axis will be proportional to the speed and length of time the input axis is turning. In a typical application (e.g. an aircraft), the output axis could have revolved 180 degrees clockwise in 20 seconds, then 80° anti-clockwise (say if the aircraft was changing direction again). This output would then be fed to a

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

to calculate the total distance traveled ( Inertial Navigation Platform).
US Dynamics Rate Integrating Gyroscope Technical Brief

Key

* Spin Axis: Spin Axis is the axis of rotation of the rotor (rotating mass). * Input Axis: Input Axis is the Axis about which the torque is applied. * Output Axis: Output axis is the Axis perpendicular to the input axis and the spin axis.

Gimbal gain

Gimbal gain is the amount of precession that can be varied by varying the viscosity of the damping fluid. For (for example) increased sensitivity of a gyroscopic instrument.

External links

Spinning Mass Gyroscopes
Gyroscopes Navigational equipment