Glossary · Control theory and process control
Auto-tuning
Also known as: Automatic tuning, Self-tuning
German: Selbstoptimierung
In control engineering, auto-tuning is a function of a controller or engineering tool that determines controller parameters automatically, typically by exciting the process with a step or relay test and deriving the parameters from the measured response.
- Control theory
In one sentence
Auto-tuning determines PID parameters automatically from a test on the process, such as a step or relay experiment.
Example
A temperature controller on an extruder zone runs a relay test at commissioning and proposes P, I and D values that the technician reviews and accepts.
How it applies
- Commissioning: Auto-tuning excites the process deliberately. Before starting it, make sure the process can tolerate the test amplitude and that limits and interlocks are active. The result is a starting point that still needs review against the required behavior.
- Operation: Some controllers retune continuously or on demand. Define who may start a tuning run, typically via an Access level on the HMI.
- Documentation: Describe the preconditions for a tuning run (steady state, loop in manual, allowed test amplitude), how to accept or reject results and how to restore the previous parameters. Record the accepted parameters as part of the commissioning record.
Auto-tuning vs. adaptive control
Auto-tuning determines parameters once or on request. Adaptive control changes parameters continuously while the loop is running. A controller can offer both, but they should be documented as separate functions.