PID...?

[ablahblah]

I didn't know what PID was until I started really browsing the forums today...From what I can gather it's being used as speed control for a launcher.

I dunno, the way we're controlling our launcher (Arm based launcher powered by flywheel. We can gauge flywheel speed via an encoder that's strapped onto the Toughbox; the output shaft rotational speed levels off as the flywheel reaches maximum speed at a set motor controller power output.

Now PID sounds sort of interesting. What difference does PID make, though, when compared to just making a few case structures in LV where the launcher is brought and adjusted every, say, 10ms, to a set speed (I'm assuming the speed comes from a scaled Joystick axis in some way, like the throttle on the Atk 3's)?