Process Control: As Taught vs as Practiced

After 47 years of industrial experience and regular reviews of technical papers submitted to this and other journals, the author has discovered a number of common threads in papers written by academics that are at odds with industrial practice in process control. These indicators of the university−industry gap are so consistent over the years as to indicate that the gap is not closing. They include the study of loops with minimum-phase dynamics, overemphasis on set-point response to the near exclusion of load regulation, omission of dynamics in the load path when covered at all, unrealistic economic considerations in objective functions, and a preference toward model-based control over PID control. Process models tend to be oversimplified, with little attention given to mass and energy balances and the bilinear models that they produce. Similarly, distributed dynamic models are rarely discussed, despite their predominance in mass and heat transfer. All this has led to research results left unused by indus...