Behind The Design 2012

[Ether]

Originally Posted by jsmeldru

We integrated the PID output. Within the PID, we only used the proportional and derivative terms.

We were able to hold our speed within +/- 50 to 200 rpm; depending on the set speed. We tuned the PID to be the most steady at the bottom of the key shot.

Thanks for the detail.

I would say our biggest issue while tuning the PID was handling the split second/recovery when the ball entered and went through the shooter. ... At one point we tried adding additional logic to "power thru" any quick decreases in shooter speed. That didn't end up working well so we just continued to tune the PID to match the majority of balls.

Spin-up recovery is where bang-bang control excels. If you've never played around with bang-bang control for a shooter wheel, that might make an interesting pre-build project. There's some detail here:

http://www.chiefdelphi.com/media/papers/2663

... make sure to read the thread too. There's a lot of good discussion in there, as well as links to other threads.