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Gyro Problems 
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Joined: Mon Oct 13, 2008 6:01 pm
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Post Gyro Problems
Hi I am new to robot C and for my FTC team I am trying to program our robot to do a perfect 90 degree using a gyro. But every time I try I'm off by about 5 to 10 degrees :breakcomputer: Can someone help me:?:


Mon Oct 13, 2008 6:21 pm
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Professor

Joined: Fri Sep 19, 2008 1:22 am
Posts: 200
Post Re: Gyro Problems
Are you changing the speed of the motors relative to how far you need to move? You will have a lot better luck with a gyro or compass if you slow way down as you get close to the target.

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Jeff McBride
Benson Robotics Club


Mon Oct 13, 2008 7:46 pm
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Joined: Sun Oct 14, 2007 3:20 am
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Location: Turin, Italy
Post Re: Gyro Problems
do you want to make a "segway"?
in this post I posted a tutorial about your problem viewtopic.php?f=1&t=647
you can start with using a pseudointegrator instead of a simple integrator. But if you you use a motor you will have some more complications.
If you like send me a PM and I will give more details.
R.

Simon

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If the facts don't fit the theory, change the facts (A. Einstein)


Tue Oct 14, 2008 9:53 am
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Post Re: Gyro Problems
Jeff McBride wrote:
Are you changing the speed of the motors relative to how far you need to move? You will have a lot better luck with a gyro or compass if you slow way down as you get close to the target.

Yeah we slowed down the motors but it still was off


Thu Oct 16, 2008 6:17 pm
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Professor

Joined: Fri Sep 19, 2008 1:22 am
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Post Re: Gyro Problems
If you post the code I would be happy to look at it for you.

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Jeff McBride
Benson Robotics Club


Thu Oct 16, 2008 6:44 pm
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Post Re: Gyro Problems
I have not had a lot of success with the gyro in terms of long term accuracy of its reading. It tends to drift. Or at least that is my recollection.

Leave the gyro in a static position. Then monitor the accumulated angle. See if it is changing over time. That is the drift.

I think the accuracy is a function of using a $50 gyro instead of a $5000 one.


Wed Oct 22, 2008 6:25 am
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Joined: Fri Nov 09, 2007 4:51 am
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Location: Hungary, Europe
Post Re: Gyro Problems
Same problems have been discussed in the "accelerometer applications" topic.
scb also recommended a simple solution called pseudo-integrator.

http://www.robotc.net/forums/viewtopic.php?f=1&t=647


Thu Oct 23, 2008 2:57 am
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