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Unread 28-02-2012, 22:58
jaysun jaysun is offline
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Re: Consistent encoder rate

Quote:
Originally Posted by slijin View Post
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.
I should clarify my last post and note that my video was not based off my actual data. I generated the "measurement" (green line) by adding a random number to the rate I set - in reality the "amplitude" of the noise is about half of that. The red line is the IIR, and the blue line is the moving average.

With the optical encoder I use the DSC.

Yes, I made sure the encoder wheels were not scratched - I scratched a lot of them when we first started using them last year. We did twist the encoder wires with a hand drill to make the wiring look good - maybe that's a problem?

Thanks for the ideas. I'll try to use a new, different encoder cable and separate the power and data wires and see if the rate I get is any less noisy.

Last edited by jaysun : 28-02-2012 at 23:01.