Monthly Archive: March 2011

Mar
29

PID Unleashed

The full power of the PID is rarely utilized. The section Industrial-Applications-of-PID-Control in the soon to be book published by Springer titled PID Control in the third Millennium: Lessons Learned and New Approaches explores key PID features and provides examples for addressing challenging applications and control objectives for common unit operation applications in the process industry.

Mar
28

Process Simulation – Part 3

This is the third posting on highlights of Chapter 15, Process Simulation, in Control Loop Foundation – Batch and Continous Processes. In my March 14 and 21st postings on process simulation I addressed some of the some basics associated with the integration of process simulation into a control system. In this posting we will start …

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Mar
25

Can’t Get No Satisfaction

Reset action is the principle source of source of overshoot, interaction, and limit cycling because reset is never satisfied. The PID integral mode will continue to ramp for insignificant offsets from setpoint. If the offset is less than the resolution limit of the measurement or valve, the best action is no action. Also, integral action …

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Mar
21

Process Simulation – Part 2

In my March 14 posting on process simulation I addressed some of the some basic technique that may be used to integrate process simulation into a control system. The P&ID often serves as the starting point in the development of a process simulation for control system checkout or operator training. In most cases, one process …

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Mar
17

Master of Space and Time

The lack of space and time kills process control innovations. The lack of space for new cables, I/O card, and new sensors and the time required for the implementation does more than just slow down implementation, space and time prevents the genesis of new ideas. As I was giving a talk to the American Institute …

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Mar
14

Process Simulation – Part 1

Process simulation can be an extremely useful tool when working with a control system. Thus, chapter 15 of Control Loop Foundation – Batch and Continuous Processes addresses how to add process simulations to a control system using tools that exist in most control systems. The material in this chapter on process simulation is broken into …

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Mar
09

Split Range Control Deminar #12 Review

The best PID solution is to eliminate the split range by the use of a valve position controller (VPC) that has directional velocity limiting (DVL) of the PID output and a dynamic reset limit (DRL) as a PID option. The enhanced PID (PIDPlus) with a sensitivity limit offers advantages for eliminating limit cycling and reducing …

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Mar
09

The Confluence of Legends

Charlie Cutler, the “Father of Model Predictive Control”, and Bela Liptak, the source of the most extensive and successful series of handbooks, will be keynote speakers at ISA Automation Week Oct 17-20 per the ISA March 7 News Release. These legends will be joined by me, Terry Tolliver, and Russ Rhinehart in a general session …

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Mar
08

Split Range Control Deminar #12 Announcement

Nearly all split range loops are oscillating across the split range point wearing out valves, reducing process efficiency, and increasing process variability. In Deminar #12, we look at major PID split range applications, problems, and innovative solutions including the use of PIDPlus. The deminar will begin at 10am North American Central time (16:00 UTC). To …

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Mar
07

Model Predictive Control

Charlie Cutler and Ramaker caused quite a stir in 1980 when they presented a paper that provided information on a new technique known as Dynamic Matrix Control. Shell Oil had developed and deployed this technique for the control of large interactive multiple input-multiple output (MIMO) processes such as refinery distillation columns. This work by Shell …

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