- By Renee Bassett
- Talk to Me
Summary
Francis “Greg” Shinskey, holder of 18 patents and author of more than 100 published papers and seven seminal books, died peacefully in September 2021 at the age of 89.
Although the first versions of the proportional-integral-derivative (PID) controller were used almost 100 years ago, Shinskey spent almost 50 years detailing the PID’s uses for different applications. Known as “the genius behind feedforward control,” he won numerous awards over his long career, including the ISA Life Achievement Award in 2008.
Shinskey’s legacy lives on in the many he instructed and inspired. “He showed how the PID is the best controller for handling unmeasured process input (load) disturbances, and also how the PID can handle interactions by relative gain analysis (RGA), decoupling feedforward signals and valve position control,” says Greg McMillan, in an article in Control Design.
“Sigifredo Nino, a Shinskey protégé, has continued his legacy, particularly in using RGA in refineries, and my entire career, except for an occasional dabbling in model predictive control, has been to make the most out of PID control,” says McMillan. “My 2015 Momentum Press book Tuning and Control Loop Performance, Fourth Edition seeks to build on what I learned from Shinskey, confirming revelations by test cases to show what a PID can do employing often underutilized key features.”
McMillan also honors Shinskey through his ISA standards-related activities. A few years ago, noting that most of the capability of the PID is underutilized, McMillan spurred the formation of ISA5.9, Controller Algorithms and Performance. This ISA working group functions under the ISA5 committee, Documentation of Measurement and Control Instruments and Systems, and seeks to clarify the algorithms used in industrial control systems and aid in their selection and application to improve manufacturing processes.
Participation in the group by leading experts has been exceptional, reports McMillan, and a 137-page ISA 5.9 technical report titled PID Algorithms and Performance has been issued for general review and comment by the committee. Ultimately, automation engineers could use the report to increase knowledge and appreciation of PID control. A digital twin with simple dynamic process simulations could enable automation engineers to build their foundation of knowledge and improve existing PID controllers, he said.
Key ISA 5.9 contributors—McMillan, Yamei Chen, Pat Dixon, Mark Darby, Cheri Haarmeyer, Peter Morgan, Sigifredo Nino, Russ Rhinehart, Michel Ruel, Nick Sands, Jacques Smuts, Hunter Vegas, and others—also plan a series of writings that will build on Shinskey’s impressive body of work and ensure that his knowledge continues to be shared.
Many people learned control engineering from Greg Shinskey. And thanks to the efforts of ISA volunteers, many more will. “The depth and extent of knowledge in his books will never be approached and may be lost to future generations,” says McMillan. “I am trying to keep his legacy alive.”
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