Should We Forget the PID Control?

Proportional-integral-derivative (PID) control represents the most used automatic control technology and the PI controller is the prevailing controller in practice. One will easily come across such statements in automatic control textbooks, but they also touch on other areas, such as artificial intelligence or signal processing. Even if hidden in the most diverse applications, PI and PID controllers can be discovered at every step of our lives. Despite this apparent dominance of PI and PID controllers, it can be shown that in reality everything can be significantly more complicated, even regulators that do not have any integrator are called integral and thus the current development of automatic control deserves more attention, precision and often substantial reassessments. This presentation is dedicated to a brief reminder of the contribution of the first pioneers in the field of automatic control, along with pointing out the roots of these misunderstandings and problems. It shows that their essence is the long-accepted equivalence of two different types of solutions, and just from the point of view of the latest research, the need for substantial corrections of several experienced approaches has been shown. And this is important not only with regard to a more correct interpretation of the past, but mainly with regard to future progress in the field of generalization and improvement of existing controllers. The delicacy of the situation is increased by the fact that a small inconsistency created a century ago can today affect a huge spectrum of solutions that have been created in the meantime, not to mention the inertia of the human factor itself.