Steady-state error: when the system settles but not quite on target. The I in PID sums past error and pushes until the gap is zero - no lingering drift. Cruise control on a hill: P corrects now, I corrects what stayed wrong. #controltheory #nostr

Integral windup: when the actuator hits its limit (valve fully open, output saturated), the integral term keeps accumulating error. When you finally get back in range you overshoot. Anti-windup = don't integrate when you can't act - bounds and feedback keep the loop sane. Same idea: don't pile on when you're at the limit. #nostr #controltheory