View Single Post
  #21   Spotlight this post!  
Unread 06-03-2012, 10:20
wireties's Avatar
wireties wireties is offline
Principal Engineer
AKA: Keith Buchanan
FRC #1296 (Full Metal Jackets)
Team Role: Mentor
 
Join Date: Jan 2006
Rookie Year: 2004
Location: Rockwall, TX
Posts: 1,171
wireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond reputewireties has a reputation beyond repute
Send a message via AIM to wireties
Re: Problems with tuning shooters using AM basketballs on Practice Field?

Quote:
Originally Posted by DampRobot View Post
Could you explain to someone ignorant why controlling with voltage is so much better than PID? I would think that you want constant rpms on the shooter wheels for maximum consistency. More success with a less sophisticated control system seems a little counter-intuitive to me...

PID is a good solution but it is not magic. The software is only one part of the servo system. In this case one can tune the wheel to free rotate at a selected speed but not have enough gain to recover quickly when a ball slows it down. So one might try to raise the gain. But then the higher gain might create an under-damped or oscillating condition when there is no load.

One approach is too build mechanical gain into the system by using stronger motors or storing energy in a flywheel etc. This gain would have much less phase delay and be more stable (I hope).

HTH
__________________
Fast, cheap or working - pick any two!
Reply With Quote