Masters of All the Tools

The Academic Visionary
Dr. Sigurd Skogestad

Dr. Sigurd Skogestad took three classes from the electrical engineering department at the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway, when he was in the Norwegian army. "However, these were rather theoretical, and during my following three-year career in the process industry, I did not find any use for these courses."

He was much more interested in thermodynamics, so when he decided to go for his Ph.D., he directed his studies towards that or process systems engineering.

"I had no plans of getting into control engineering," Skogestad recalls, "but then Professor Manfred Morari of CalTech came to visit our company [Hydro, www.hydro.com] and gave some lectures on the pinch method for heat exchanger network design. I was very impressed with him, and I joined his group at CalTech. The main focus of his work was control, and I became fascinated with the power of feedback control."

Skogestad relies on his four years of experience at Hydro's research center in Porsgrunn, Norway, to shape his work. "I have always had a strong interest in doing work that engineers may find useful in their daily work," he says, "and my first control paper was a paper on PID tuning that was written during my first year as a Ph.D. student." In fact, this paper has been so useful that it is still Skogestad's paper with the most citations in other works. "Presently at 365 citations," Skogestad says.

Skogestad was born in the small town of Flekkefjord, Norway, but moved to South Africa with his family for the next five years. Moving back to Norway, he finished high school in Porsgrunn, certain that he wanted to study engineering. "I ended up in chemical engineering because my father was a chemical engineer and working in large chemical plants seemed interesting and challenging," he says.

Sigurd married Anne-Lise when he was still a student, and they have two boys and two girls. Since he returned to Norway in 1987, he has been a professor of chemical engineering at NTNU and has been head of the chemical engineering department for some time. He is an avid cross-country skier and hunter, mostly of grouse. He is also a fan of orienteering, or "running with compasses." Skogestad is also active in local politics, as well as being a coach and umpire for girls' baseball.

"I think my main contribution," he says, "and one I am still working on, is to take control theory and make it workable in practice. As you can see if you look at my home page (www.nt.ntnu.no/users/skoge/bio.html), ‘the object of our research is to develop simple, yet rigorous methods to solve problems of engineering significance. We would like to provide the engineer with tools to assist in problem solving.' "

Skogestad has been working on plant-wide control for 25 years. "I am trying to find a systematic approach for finding the right control strategy, especially for finding the best controlled variables (CVs). I expect to keep working at least for another 15 years."

You can find his paper, "A Systematic Approach to Plant-Wide Control" at www.controlglobal.com/plantwidecontrol.html. "The paper summarizes my efforts so far…" he notes.

The Batch Wizard
Dr. Maurice Wilkins

"It was 1978," says Dr. Maurice Wilkins, vice-president of global marketing services for Yokogawa Electric of America (www.yokogawa.com/us/), "and I was just finishing my Ph.D, when a friend of mine who had graduated the year before to join Esso Chemical Ltd. in the New Forest area of southern England called to tell me about a cool new project he was working on using a new control tool called a DCS."

It was a Honeywell TDC2000 with eight loops and a single data entry panel.

Wilkins continues his story: "At the time I knew nothing about process control—we had done some on the chemical engineering course I had taken—but not much, and my Ph.D. studies had been on the control of water pollution using activated charcoal cloth. He said that Esso was looking for one more control engineer and 17 process engineers, so I decided to apply, and got the job. I was on a Honeywell training course while still writing my Ph.D. thesis. I remember my first day at Esso Chemical—my boss pointed to a line of columns and told me that I would be responsible for putting all of them onto TDC2000 and adding advanced controls—and so began my first project."

"Esso was very good at giving basic control training to its engineers," Wilkins says, "and then throwing them in at the deep end—and boy, did I learn a lot quickly." Like Berra, Wilkins spent lots of time working on every type of process unit. Then he was sent to Esso's additives plant called Paramins, and this changed his life. He was sent there to learn the ins and outs of batch control.

"It was seen as 'relegation' by the continuous control ‘elite,' " Wilkins remembers, "but boy, did I have some fun there."

Wilkins took his new found batch expertise on the road, teaching process automation for KBC Process Automation's (now Honeywell Process Solutions) batch group for the next three years. He spent 18 months working on a huge batch project for Shell with Foxboro NL, the Dutch subsidiary of Foxboro (www.foxboro.com), and while there he learned about Easybatch, a Foxboro product far ahead of its time that used subroutines to control operations in the way ISA-88 later used phases. Moving to Honeywell (http://hpsweb.honeywell.com), he became involved in creating Modular Batch Automation, which was a forerunner to ISA-88.