Robust advanced PID control (RaPID): PID tuning based on engineering specifications

The success of proportional-integral-derivative (PID) control in the process industry is based on the ability to stabilize and control around 90% of existing processes. This importance is overshadowed, however, by a lack of performance in some applications. It has been reported that a significant percentage of installed PIDs are operated in manual mode and that 65% of the loops operating in automatic mode generate greater variance in closed-loop operation than in open-loop operation. These challenges motivated the development of the software package robust advanced PID control (RaPlD) for tuning PID controllers. RaPID is an intuitive tool with multiple levels of complexity that can be accessed according to the knowledge of the person commissioning the loop. This article describes the methods and algorithms used by RaPID for tuning PID loops.