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Unread 28-02-2012, 22:34
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AKA: Samuel Lijin
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Re: Consistent encoder rate

Quote:
Originally Posted by jaysun View Post
I tightened the encoder discs on the axle as shown in the video, and I made sure there wasn't any slipping. When I rotated the encoders by hand, the Distance count was kind of consistent: I'd say about +-10 counts.

I tested an IIR filter of the encoder speed and compared it to a moving average. You can see an example of my results in this video. The problem with the PID loop adjusting the speed is still present. I'm still not sure if there is a good filter or not.
That's an extraordinarily noisy signal. Is the green the moving average and the red the IIR? Also, just out of curiosity: how are you obtaining the encoder input, through a Jaguar or the DSC?

I don't know about you, but we ran into issues with scratched encoder wheels and damaged encoder wires (there was no visible damage; I assume it was internal from abusive zip-tying, but swapping out the wire resolved the issue).

A bit of advice I've been given by my mentor (although I've never personally experienced this problem) is to always separate signal runs from power runs so that the power runs don't induce noise in the signal; if they have to cross, run them at right angles. Ether would be able to elaborate more on this.
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