paper: Shooter Wheel Speed Control

[Tom Line]

I'm interested in teams claiming +/- 15 rpm accuracy.

We've implemented robust PID control, and today implemented bang-bang control as a second option.

We tried 4 different high speed encoders, 2 bourn, 1 grayhill, and 1 honeywell. The noise in our 'best' situation (completely unfiltered running off the get rate from the encoder, encoder set to 1x decoding, get rate in a timed loop of 10ms) was +/- 60 RPM.

The best the bang-bang loop could do completely unfiltered was around +/- 100 RPM.

The best the PID loop could do completey unfiltered was arond +/- 80 RPM.

The PID loop spins up in 3 seconds. The bang-bang in about 1.5 seconds.

I'm curious what teams are using to measure their system to gain +/- 15 RPM accuracy without noise problems.

Should we be using an IIR or moving average filter to filter the incoming rate from the encoder to minimize noise effect on the bang-bang? (That's the geekiest sentence I've typed in a long time).