Who invented the PID controller ???????

Question

i need to know the real inventor of the PID (Proportional-Integral-Drevative) controller, it's about history ..... thx

Answer 1

Probably several engineer/mathematicians around the 1930's. We can easily see why it was invented if we think about the error in a position servoo : 1. we need to predict or advance the error moving boundary as we approach coincidence 2. We can see why we must have an error if we do not have integration in the loop circuits or devices to evenyually reduce the error to zero. Of course, some of the above 'frills' can cause instability in the loop if we do not study 'loop compensation or shaping methods'. Bode was of corse famous in this, as was Nichols . But this stuff started way before in the Bell System Tech Journal- with closed loop amplifiers for telephone repeaters (amplifiers for hudreds of miles of line/cable. Many more early names , also in mechanical and pneumatics-- especially in the oil refining controls which used or still use pneumatics ? for safety and ease of assembly by unskiled. ALL the PID functions are easily accomplished with pneumatics (15 psi). They use a nozzle-flapper and back pressure as the primary hi-gain amplifier together with expandable bellows and small nozzles to give leaks for air. The final power element is a large diam diaphragm which move a valve or whatever with any force you want. MUCH more to tell ! Probably did not bring out that it all started with feedback theory and closed loop servos. Thes closed loops started in the early days of amplifiers and telephony, hence Ma Bell . Black is a famous name as is of course Nyquist and James-- many more. Have a look at MIT Rad Lab Series books after WWII , there is a volume on servos and probably others in the series. Of course, the feedback system exists in human motions.

Answer 2

Richard Phelan