Very early attempts at this continuous control of systems under load were seen as far back as the 1600s. One of the earliest examples was invented in the 17th-century when a centrifugal governor mechanism (based on rotating weights) was designed to compensate for increasing differential in rotation speeds between larger and smaller millstone wheels under higher loads.
In 1922, Nicolas Minorsky made a real breakthrough towards what we now recognise as true PID control. Minorsky's observations and mathematical treatment would eventually evolve to give us the electronic industrial control mechanisms widely used as PID systems today.
PID controllers are now used widely in many industrial processes and they have become some of the most common items of automation and control gear used across multiple sectors and industries. This is largely due to the fact that PID controllers are ideally suited to delivering dependable, robust performance across a broad spectrum of environments and applications. They are also inherently user-friendly and simple in terms of both design and operation.