Tag Archive: PID

Mar
18

Impact of Changing Process Gain

From a control perspective, it is highly desirable that the process gain is constant. If the process gain is constant, then the same proportional gain can be used over the entire operating range of the control loop. Using a control valve as an example, if the valve characteristic was not properly selected based on the …

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Mar
11

Evaluating Valve/Actuator Performance

When a control loop is placed in automatic control, it is easy to detect if a valve or actuator is not responding correctly to the control system. As discussed in Chapter 3 of Advanced Control Foundation – Tools, Techniques and Application, this can be done by observing the response of the controlled parameter to control …

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Mar
04

Addressing Incorrect Tuning

A Loop tuning has a significant impact on control loop utilization and performance. Controller tuning parameters can be easily changed over a wide range to adjust loop operation for various process requirements. However, some expertise in tuning is required even when advanced control tools are used, and there is a chance that the behavior of …

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Feb
18

Improving Control Utilization

When the utilization of a control loop is found to be low during normal plant operation, the measurement or control problems that prevent the control loop from functioning in its normal (designed) mode of operation should be further explored. In Chapter 3 of Advanced Control Foundation – Tools, Techniques, and Applications we outline the steps …

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Feb
11

Control Utilization

It can be shocking to examine control utilization in a plant where performance tools have not been installed and/or not used. For example, in the mid-1980s a control survey was conducted at a major pulp and paper plant where the control system had recently been updated to the latest distributed control system. At that time …

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Jan
07

The Semantic Web – Control Loop Foundation

When Mark Nixon and I wrote Control Loop Foundation – Batch and Continuous Processes we also worked with Paul Muston and Deb Franke to create a web site that goes with the book. Anyone may go to this web site to perform the 19 workshops that are included in the book. When you select a …

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Dec
17

Future Technology Trends

Professor Åström is well known throughout the world for his work in process control. The book he co-authored with Tore Hägglund, Advanced PID Control, is one of the most comprehensive texts on this topic. In the early 1990’s Professor Åström was a consultant to the Emerson team that did the basic research for the development …

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Dec
10

Foundation Book Promotional Kit

The single loop and multi-loop control techniques most often used in automating continuous and batch processes are addressed in the book Control Loop Foundation – Batch and Continuous Processes. Similarly, the advanced control techniques that are most often utilized in the process industry are addressed in the book Advanced Control Foundation – Tools, Techniques, and …

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Dec
03

Chinese Translation of Control Loop Foundation

A translation of the book Control Loop Foundation – Batch and Continuous Processes is now available on the ISA web site as an e-book in ePub or mobi format. The ePub format is used by most dedicated e-book readers such as Android devices and iPad, iPhone, and iPod, Kobo eReader and Sony Reader. The mobi …

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Nov
26

Addressing Control Applications Using WirelessHART Devices

I traveled to Germany earlier this year for a meeting with Namur to present Emerson’s approach for addressing control applications using WirelessHART devices. WirelessHART transmitters have been installation by many plants in Europe. The reliability of these devices has been well established and many of these plants are now interested in using WirelessHART transmitters in …

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