[Ken Streeter]

Originally Posted by Thad House

A Bang Bang Controller mode would be cool as well. I know the teams that used it in previous years, including us liked it alot. Would be cool having it just integrated into the controller.

I believe that you will get "Bang-Bang Controller" functionality from the built-in PIDF if you set Kp = infinity (just choose a really big number) and set Ki = Kd = Kf = 0. For "flywheel" applications, you'll also need to constrain the minimum output to be 0, so that when the flywheel is over the target speed, the controller doesn't "Bang" to maximum reverse.

In 2012, we used a bang-bang controller for our basketball-shooting flywheel. It worked pretty well. In 2013, we started out using a bang-bang controller for our full-court shooter -- it was pretty good, but not good enough for FCS. With experimentation during the 2013 season, we found that a PF controller (PIDF where I=D=0) worked more smoothly and more accurately. As mentioned above, PIDF with Kp=infinity and Ki = Kd = Kf = 0 degrades to bang-bang, so it's easy to test both alternatives by just varying the parameters while the robot is operating. For us in 2013, the improvements made the difference between FCS that nearly worked and actually did work. Retrofitting the improvements to our 2012 robot increased our accuracy shooting basketballs, too.

We're planning to use the Talon SRX this year with the built-in PIDF for most of our control loops. Haven't gotten them working yet, but that's been due to cabling issues, rather than problems with CAN or the Talon SRX.