I know of a team I am trying to help and is cautiously going down the path of PD loops with a NAVX on our Roborio to balance our robot during autonomous for this season. I know very little of PD loops and I am sure there are plenty of Mentors and Teams out there that have a ton of experience. Is there anyone that can help in this area? Any help is greatly appreciated!
WPIlib has a great intro to what PID is that does an excellent job with feedback control loops. PID is a fairly complex topic, but it’s essence isn’t too hard to understand. Pretty much, you tell the loop where you want it to be (called the setpoint), and feed it data on where the thing actually is so it can calculate how far away from the setpoint you are (called the error). P, I, and D stand for the three constants that control how the robot goes about handling the error safely. It functions like the shocks of a car.
Highly recommend reading that documentation though, because it goes into good detail about how all of the math actually happens and how to troubleshoot problems.