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Unread 15-02-2012, 17:54
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Re: PID Velocity Control
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Originally Posted by j.cole View Post
I see what thats for because I'm doing some testing right now and the encoder rate is really jumpy.
Yup. Try delta_counts and you should see a much less noisy signal. Did you see the little drawing I attached to the previous post? It shows a feedback node.
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Unread 15-02-2012, 18:00
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Re: PID Velocity Control
Didn't work. I tested it at 1/4 voltage and the value I was getting from the encoder was jumping from 2.6 max to 1.8 min. Is there any way to average that number and stay in the middle? I've been our programmer for 3 years but I'm new to advanced programming techniques.
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Unread 15-02-2012, 18:34
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Re: PID Velocity Control
Alright I think I found the problem. I changed the Decoding Rate in the begin from 4x to 2x. That dropped the variation from +-.5 to +-.05 . I'm going to try 1x now and see what it looks like.
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Unread 15-02-2012, 19:08
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Re: PID Velocity Control
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Didn't work.
What "didn't work" ?? There's no context available for disambiguation.

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Unread 16-02-2012, 13:17
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Re: PID Velocity Control
Doing the delta counts didn't fix the problem which was the jumpyness of the encoder values at a constant voltage. I think that properly tuned I could negate the effects of that variation.
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Unread 16-02-2012, 13:31
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Re: PID Velocity Control
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Originally Posted by j.cole View Post
Doing the delta counts didn't fix the problem which was the jumpyness of the encoder values at a constant voltage.
At what encoder speed (RPM) were you seeing jumpyness of the encoder values using the delta_counts method?


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Unread 17-02-2012, 10:55
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Re: PID Velocity Control
(I just took the delta counts so I'd say it's RPS not RPM) But I tried everywhere between .5 RPS and 5 RPS and the variance is still the same. I want to say it has something to do with the rate TeleOp runs but I don't know.
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Unread 17-02-2012, 11:07
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Re: PID Velocity Control
Quote:
Originally Posted by j.cole View Post
(I just took the delta counts so I'd say it's RPS not RPM) But I tried everywhere between .5 RPS and 5 RPS and the variance is still the same. I want to say it has something to do with the rate TeleOp runs but I don't know.
If there's excessive jitter in TeleOp, try dividing delta_counts by the actual elapsed time instead of the assumed 20ms.

Is this for a shooter wheel or something else?


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