Tag Archive: “non-linear”

Jul
22

Adaptive Tuning – Example Application

Adaptive Tuning Example

It is often possible to spot where adaptive control is needed by observing trends of control loops that show the control parameter and valve position during a time period when the process conditions change over their normal span of operation. If the control performance varies with changes in operating conditions, then adaptive tuning may be …

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Jul
15

Adaptive Tuning – Field Experience

Reduction in Process Variability

The adaptive tuning capability included in DeltaV was field tested at four customer sites during the initial stages of product development. This field trail was conducted over a six month period and include over 1000 control loops. One of the field trail sites was at Lubrizol, Deer Park, TX where this adaptive control capability was …

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Jul
01

Adaptive Tuning – Model Switching

Adaptive PID Controller With Model Switching and Parameter Interpolation

During the development of the DeltaV adaptive tuning capability, we researched and evaluated many of the most common techniques for implementing adaptive tuning. Also, as part of this research we came across a number of technical articles on a relative new adaptive tuning technique known as model switching. This technique depends on the evaluation of …

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Mar
18

Impact of Changing Process Gain

non-linear valve characteristics

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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