Tagged Content List
  • Blog Post: Application of Kalman Filtering in DeltaV

    A paper published in 1960 by Rudolf Kálmán “A New Approach to Linear Filtering and Prediction Problems” is the basis for the Kalman Filter. The Kalman filter has been successfully used in a wide variety of applications: • The guidance of commercial airplanes • Seismic data processing • Nuclear power...
  • Blog Post: Commissioning PI Control – Integrating Process

    When the control objective is to maintain the controlled parameter of an integrating process at setpoint under all operating conditions, then using PI (proportional-integral or proportional plus reset) controller, it is possible to automatically compensate for changes in disturbance inputs and maintain...
  • Blog Post: Surge Tank Control

    Intermediate liquid storage tanks (surge tanks) are commonly installed between processing areas of the plant. Under normal operating conditions, these storage buffers allow each process area to be operated independently of the other process areas. Any imbalance in the area production rates within a plant...
  • Blog Post: On-demand Tuning Example

    Control system manufacturers have adopted different technologies to implement on-demand tuning. Because these tools are designed to work in a noisy process measurement environment, the tuning results are usually better than those achieved through manual tuning techniques. To illustrate the features that...
  • Blog Post: Selecting Control Response

    After the process characteristics are identified, the information is then used to calculate the recommended loop tuning. The tuning rules used to derive controller parameters from process characteristics can be chosen as appropriate for the specific process and the desired speed of response. As addressed...
  • Blog Post: Performance Monitoring Tools

    Many control system manufacturers and third party companies now offer tools that are designed to monitor process control and instrumentation performance. In addition to providing on-line information that summarizes control utilization, the user may access other information that may be helpful in determining...
  • Blog Post: Addressing Loop Interaction

    In some cases, the manipulated parameter of one control loop can impact the controlled parameter of another control loop as illustrated below. To allow both loops to operate in automatic mode, loop interaction is most often addressed by simply detuning one of the control loops by reducing the proportional...
  • Blog Post: Split Range Setup

    One of the most common ways of addressing multiple process inputs is split range control. A splitter block, which appears as one valve to the PID block, can be used in the control strategy to define a fixed relationship between the controller output and each manipulated process input. In Advanced Control...
  • Blog Post: 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...
  • Blog Post: 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...
  • Blog Post: Identifying Transmitter Problems

    One of the most obvious reasons for poor control utilization is a broken or unreliable transmitter or sensor. As addressed in Chapter 3 of Advanced Control Foundation – Tools, Techniques, and Applications, if the control system is designed to be consistent with the international function block standard...
  • Blog Post: 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...
  • Blog Post: 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...
  • Blog Post: Evaluating Control Performance

    A plant operator is usually responsible for managing one or more process areas, with (potentially) hundreds of control loops and process measurements in each area. The operator’s job is made easier if the control loops in these process areas are in automatic mode and can compensate automatically for...
  • Blog Post: Assessment of Control Performance

    To achieve the maximum benefit, the performance monitoring tools that are installed in control systems to evaluate plant control performance should contain features to support both analysis and diagnostics. Process Analysis is the examination of a process, its elements, and their relationships. Process...
  • Blog Post: 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 … Continue...
  • Blog Post: 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...
  • Blog Post: 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...
  • Blog Post: 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...
  • Blog Post: Meet The Expert Session – Advanced Control Foundation

    As I mentioned in an earlier blog, Willy Wojsznis and I hosted a Meet the Expert session at Emerson Exchange 2012 that covers key points contained in the book Advanced Control Foundation – Tools, Techniques, and Applications. Below is a picture from this session. I received permission from the Emerson...
  • Blog Post: Advanced Control Foundation at Emerson Exchange 2012

    The International Society of Automation (ISA) always has a booth at Emerson Exchange to display books published by ISA and make these books available for purchased. The book that Mark Nixon, Willy Wojsznis, I co-authored this year, Advanced Control Foundation – Tools, Techniques, and Applications was...
  • Blog Post: Emerson Exchange 2012

    If you attended Emerson Exchange 2012 in Anaheim, California, Oct 8-12th then I am sure you will agree this event exceeded all expectations. With over 350 workshops and short course to select from, it was always easy to find a presentation of interests. The exhibit area was open the first three days...
  • Blog Post: Advanced Control Foundation at ISA Automation Week 2012

    If you are attending ISA Automation Week, 2012 then you may want to stop by the ISA book store in the exhibit area. Copies of Advanced Control Foundation were shipped earlier this week from the printer and arrive at the ISA bookstore late today, Tuesday, September 25. Thus, you might say these copies...
  • Blog Post: Control Loop Foundation Class – Nov 5-9

    I worked closely with Emerson’s education department to establish the class Control Loop Foundation (9025). This 4 ½ day class is intended primarily for people who are new to the process industry and process control. Approximately 30% of the class is dedicated to workshops in which the students get hands...
  • Blog Post: Advanced Control Foundation – Book’s Web Site

    A workshop is provided at the end of each chapter of Advanced Control Foundation – Tools, Techniques, and Applications that explores the technology. One of the unique features of the book is that the reader may view the workshop solution by going to the web site (http://www.advancedcontrolfoundation...