Rate integrating gyroscope
Encyclopedia
A Rate integrating gyroscope is a rate gyro
with a built in integrator
. It is usually a component of an Inertial Measurement Unit
or a stabilization system.
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 about the output axis.
The rate indicating gyroscope consists of a damping
fluid between the float assembly can and the outer casing. This viscous fluid resists the motion of the gimbal
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 80o anti-clockwise (say if the aircraft was changing direction again).
This output would then be fed to a computer
to calculate the total distance traveled (Inertial Navigation Platform).
Rate gyro
A rate gyro is a type of gyroscope, which rather than indicating direction, indicates the rate of change of angle with time. If a gyro has only one gimbal ring, with consequently only two planes of freedom, it can be adapted for use as a rate gyro to measure a rate of angular movement.Rate gyros...
with a built in integrator
Integrator
An integrator is a device to perform the mathematical operation known as integration, a fundamental operation in calculus.The integration function is often part of engineering, physics, mechanical, chemical and scientific calculations....
. It is usually a component of an Inertial Measurement Unit
Inertial measurement unit
An inertial measurement unit, or IMU, is an electronic device that measures and reports on a craft's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes. IMUs are typically used to maneuver aircraft, including UAVs, among many others, and...
or a stabilization system.
Principle of operation
In a rate indicating gyroscope, the gyroscopeGyroscope
A gyroscope is a device for measuring or maintaining orientation, based on the principles of angular momentum. In essence, a mechanical gyroscope is a spinning wheel or disk whose axle is free to take any orientation...
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 about the output axis.
The rate indicating gyroscope consists of a damping
Damping
In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system, particularly the harmonic oscillator.In mechanics, friction is one such damping effect...
fluid between the float assembly can and the outer casing. This viscous fluid resists the motion of the gimbal
Gimbal
A gimbal is a pivoted support that allows the rotation of an object about a single axis. A set of two gimbals, one mounted on the other with pivot axes orthogonal, may be used to allow an object mounted on the innermost gimbal to remain immobile regardless of the motion of its support...
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 80o anti-clockwise (say if the aircraft was changing direction again).
This output would then be fed to a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
to calculate the total distance traveled (Inertial Navigation Platform).
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 force is applied.
- Output Axis: Output axis is the Axis perpendicular to the input axis and the spin axis.