1 / 6

Understanding and Fixing Out-of-Tune Controllers in Feedback Systems

In the second part of our feedback control series, we explore how controllers can go out of tune due to improper setup, physical changes in the environment, or worn components. Recognizing these issues involves understanding signs like sustained oscillations, operational complaints, and the controller being in manual mode. To address these problems, it's crucial to comprehend the control objectives, analyze current configurations, model the transfer function, and design a new controller if necessary. Examples include vehicle control, extrusion thickness control, and more.

maitland
Télécharger la présentation

Understanding and Fixing Out-of-Tune Controllers in Feedback Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Feedback Control Roundup Part 2

  2. How do controllers go out of tune? • How can I recognize them? • What do I do?

  3. How do controllers go out of tune? • One of three reasons: • It was not set up properly in the first place • Something in the physical world has changed • Worn parts - valve, motor, dampers, etc. • Change in operating conditions affected the transfer function • Flow rate affecting time constant • Pressure affecting gain • Some Mech E installed a new piece of equipment • Someone changed it because they didn’t like it • Usually decreasing Kc or increasing I to make the controller less responsive.

  4. How can I recognize them? • Controller in manual (turned off) • Sustained oscillations • Complaints from operators (users) • Occasionally, equipment damage, usually from too-aggressive a controller.

  5. What do I do? • Understand the control objective • Understand the current control configuration and why it is not meeting the objective • Figure out the process: • inputs, outputs • Rough idea of relationship(s) between input(s) and output(s) • Transfer function model(s), time permitting • Design a controller for the process to meet the objective • IMC tuning • Simulate the controller in closed loop to make sure you got it right, and to be sure it will work if the process changes • Implement the controller • If you understand the effect of Kc and I, skip steps 3 and 4 and change them directly, but carefully.

  6. Physical Examples • Vehicle control • Thickness/width control in extrusion • Engine control: fuel injection under load • Antenna position on moving vehicle

More Related