Steps to Optimize Your Control Loop
- Ask operations personnel about problems or other comments they have about the loop.
- Collect normal operating data. Is the output operating near a limit? If so is sizing correct? Click the statistical analysis button and review.
- Use ExperTune's hysteresis and stiction checkers to test that the valve is working properly.
- Check for hidden cycles using Power Spectral Density.
- Check the linearity of the loop using ExperTune's
characterizer.
If non-linear by 3 or more it is best to apply the characterizer ExperTune built for you. If you are working with a pH loop, linearize it first. - For level loops (tanks etc.), then run the level wizard to guide you to the optimal control based on your objectives.
- Click the Tune button to request optimal PID values. View the robustness plot to analyze the trade off between tight tuning and sensitivity to process changes. Check the inverse response button, if appropriate.
- Evaluate ExperTune's recommended PV filter for increased valve life.
- For interacting loops or cascades use ExperTune's RRT analysis to decouple interactions or verify the cascade inner and outer loop design.
For each of the above steps you do, we recommend that you click the "Add to Report" button. Then when you are finished, ExperTune will have created a complete report of the work you performed.
