Common Industrial Applications of PID Control

By dennisnash | October 22, 2015

A previous post about the Derivative Term focused on its weaknesses. As noted, the primary challenge associated with the use of Derivative and PID Control is the volatility of the controller’s response when in the presence of noise. Noise is a major stumbling block for Derivative and PID Control as production data is routinely replete with process noise and other sources of variability. The use of PID Control in such an environment can drive frenetic changes in a loop’s Controller Output (CO) and unnecessarily wear out the associated Final Control Element (FCE). In summary: Little to gain; lots to lose.

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Common Industrial Applications of PI Control

By dennisnash | October 14, 2015

Studies show that when individuals are given a set of three options they are instinctively biased to prefer the middle one. When this finding is applied to purchasing behavior a common outcome is that consumers pick the middle priced option with little-to-no rationale other than a desire to avoid being viewed as either too cheap or too lavish. It’s known as the Compromise Effect.  While the PID controller offers three options – P-Only, PI and PID – the rationale for selecting the middle option is generally clear. But PI Control is not only the instinctive choice, on many occasions it is also the superior and simpler one.

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What is the Purpose of a PID Controller’s Integral Term? Why is PI Control So Widely Used in Industry?

By dennisnash | September 9, 2015

In the realm of process control it makes complete sense that the primary goal is – you guessed it – to control the process.  For decades the PID controller has proven a reliable tool for fulfilling that objective.  Even so, there are various forms of the controller that can be used and each has its unique performance attributes.  In spite of the added complexity associated with the Integral Term the PI controller is the form most widely used in industry.

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