PID Explained for Process Engineers: Part 1 — The Basic Control Equation

The differential equation for PID control contains three possible modes:
• proportional
• integral
• derivative.

This three-part series of articles explains the proportional-integral-derivative (PID) control equation in language that process engineers, most being chemical engineers, can readily understand.

• Part 1 focuses on developing the basic equations differential and difference equations for PID control

• Part 2 examines the tuning coefficients (February 2016 issue)

• Part 3 explains the most common controller features and options (March 2016 issue)