Glossary · Control theory and process control
Manual tuning
Also known as: Hand tuning, Trial-and-error tuning
German: Manuelle Reglereinstellung
In control engineering, manual tuning is the setting of controller parameters by a person who changes them step by step while observing the loop response, instead of using an automatic tuning function.
- Control theory
In one sentence
Manual tuning sets controller parameters step by step by observing the loop response, relying on the engineer's experience.
Example
The commissioning engineer raises the proportional gain of a pressure loop until it starts to oscillate slightly, then reduces it and adds integral action until the response settles cleanly.
How it applies
- Commissioning: A common sequence is: start with P only, increase gain until the response is fast but acceptable, then add integral action to remove offset and derivative action only if needed. A Trend display of setpoint, measurement and output is the essential tool.
- Operation: Manual tuning on a running plant disturbs production. Agree the test window with operations and keep limits and alarms active.
- Documentation: Record the parameter values before and after, the reason for the change and the observed result. Where only qualified staff may tune loops, the HMI Access level and the service manual should say so.
Manual tuning vs. auto-tuning
Auto-tuning runs a defined test and computes parameters. Manual tuning depends on the person, but it lets an experienced engineer take account of constraints the algorithm doesn't know, such as valve wear or interaction with neighboring loops.