PID vs Bang-Bang for Shooter Consistency

[lori558]

Currently our team is having problems with shooter consistency. Both PID and Bang-Bang have yielded negative results for us.

We are using a photoswitch (provided in 2011 KoP) in place of an encoder...

With PID programming, we used the counter and wired it into a PID function and attached the output to the motor. However, according to the gains we test, the wheel will either not move, jerk back and forth, or spin at full power. Thus far, we have never been able to get PID to work.

With the Bang-Bang theory, we used the example provided by Billbo911 located at http://www.chiefdelphi.com/media/papers/2665.
We have 1 stripe on our wheel and thus the numbers on the example were indeed changed from 360 to 1. So that is not the problem. When tested, the wheel would either not do anything or would spin at full power.
We have gone through the thread http://www.chiefdelphi.com/forums/sh...d.php?t=113029. The modified code in there has been tested as well and that seemed to yield some results. The wheel would spin according to the number that was put in, however, the shots we fired were not very consistent. Therefore that leads us to believe that the code was not working for us.

Ultimately, our goal is to make our frisbee shots consistent. We have researched a lot on this idea and not much seems to be working for us.

Additionally, the idea has been brought up that I might as well ask here; is it reasonable to use battery voltage as a factor and create a wheel speed equation that consistently maintains the desired speed by taking battery power into the equation?

Bottom line is how can we get a consistent shooter if neither PID nor Bang-Bang theory is working for us? And if there is no other option, why is our code not working?

If anyone could help out on this that would be great!