Fiber Optic Gyros

  • #1

Main Question or Discussion Point

Hello every body. Has anybody used Fiber Optic Gyros? How accurate they are? How about the price range? Could any body help me select a suitable actuator system/motor mechanism for, say a camera stabilization or a gun stabilization using a fiber optic gyro. I want to get rid of mechanical gyros.
 

Answers and Replies

  • #2
Baluncore
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What do you mean by “mechanical gyros”? Spinning flywheels or MEMS?
http://en.wikipedia.org/wiki/Vibrating_structure_gyroscope

Fiber Optic Gyroscopes are laser gyroscopes. They are more accurate than mechanical or ultrasonic / MEMS gyros. The problem with FOGs is that they require a spool with many hundreds of metres of optic fibre as a laser light path and a digital processor. That makes them bulky and require a significant power supply. To stabilise a targeting system would require at least two FOG modules. FOGs are suitable for navigation because they can sense the rotation of the Earth and so find the True North meridian. They make an accurate compass, something that MEMS cannot do.

3D MEMS gyroscopes are now the obvious choice for fast servo stabilisation of handheld or tripod mounted platforms or equipment. They are light weight, robust, low power and have a fast response.
 
  • #3
Doug Huffman
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There is the Ring Laser Gyro, much more compact. FOG fibers are noted at 5 km.
 
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  • #4
What do you mean by “mechanical gyros”? Spinning flywheels or MEMS?
http://en.wikipedia.org/wiki/Vibrating_structure_gyroscope

Fiber Optic Gyroscopes are laser gyroscopes. They are more accurate than mechanical or ultrasonic / MEMS gyros. The problem with FOGs is that they require a spool with many hundreds of metres of optic fibre as a laser light path and a digital processor. That makes them bulky and require a significant power supply. To stabilise a targeting system would require at least two FOG modules. FOGs are suitable for navigation because they can sense the rotation of the Earth and so find the True North meridian. They make an accurate compass, something that MEMS cannot do.

3D MEMS gyroscopes are now the obvious choice for fast servo stabilisation of handheld or tripod mounted platforms or equipment. They are light weight, robust, low power and have a fast response.
Yes spinning wheel gyros
There is the Ring Laser Gyro, much more compact. FOG fibers are noted at 5 km.
There is the Ring Laser Gyro, much more compact. FOG fibers are noted at 5 km.
But Ring laser gyros have frequency lock in issue. Secondly they have very poor response to slow angular rates, i.e they do not sense slow angular change
 
  • #5
Yes spinning wheel gyros



But Ring laser gyros have frequency lock in issue. Secondly they have very poor response to slow angular rates, i.e they do not sense slow angular change
Spinning wheel gyros do not need a separate actuator for the counter torque against precession.
 
  • #6
Baluncore
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Secondly they have very poor response to slow angular rates, i.e they do not sense slow angular change
But a camera or gun needs to be stabilised only over a period of a few seconds at most.

Spinning flywheels stabilise the platform without need for a servo system.

FOGs, ring lasers and MEMS all sense orientation changes and require a servo system to stabilise the platform.
 
  • #7
But a camera or gun needs to be stabilised only over a period of a few seconds at most.

Spinning flywheels stabilise the platform without need for a servo system.

FOGs, ring lasers and MEMS all sense orientation changes and require a servo system to stabilise the platform.
Accuracy is the key. Spinning flywheels cannot provide the accuracy one needs in gun stabilization. Thats why people have switched to modern gyros like Fiber Optic gyros and Ring Laser Gyros.
 
  • #8
Baluncore
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Accuracy is the key.
What are you trying to stabilise?
What is it mounted on?
What accuracy do you require over what period of time?
How will you remove Earth rotation from your platform?
 
  • #9
What are you trying to stabilise?
What is it mounted on?
What accuracy do you require over what period of time?
How will you remove Earth rotation from your platform?
Well I am doing a project on gun stabilization. It could be mounted any moving platform, say a vehicle.
Time should be as short as possible of course. Greater the accuracy, greater would be the project.
 
  • #10
And, do we need separate motors for stabilization module or integrate the output from gyros to the azimuthal and traversal motors used for the gun control?
 

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