PD-09-113 Removing the Trials and Tribulations of PID Tuning

Description:

A new approach based on optimization technology is described for reducing the time and effort required to tune PID loops, without the need to iterate. For interacting loops, modern identification techniques are used to develop an accurate multivariable dynamic model. For single loop applications, simplified modeling techniques tailored to instrument technician level can be used. The resulting model is used in an optimization that explicitly considers process-specific safety and operability objectives associated with the controlled and manipulated variables to determine optimal PID tuning parameters. A key feature of the approach is that robustness margins are explicitly addressed to ensure stability in case of future plant-model mismatch. In the following sections, the methodology and technology are described in detail. Results are presented for an interesting industrial application.