Glossary · Control theory and process control
Controller tuning
Also known as: Loop tuning, PID tuning
German: Reglereinstellung
In control engineering, controller tuning is the selection of controller parameters, such as proportional gain, integral time and derivative time, so that a control loop meets its requirements for stability, speed and disturbance rejection.
- Control theory
In one sentence
Controller tuning sets parameters such as gain and integral time so a loop is stable, fast enough and rejects disturbances.
Example
After replacing a pump, the technician retunes the pressure loop because the new pump reacts faster and the old gain caused oscillation.
How it applies
- Engineering: Tuning methods include rules based on step or oscillation tests, model-based methods and optimization against a performance index such as Integral absolute error (IAE). Specify the goal first: fast setpoint tracking and good disturbance rejection often need different parameters.
- Commissioning: Record the initial and final parameters, the method used and the test results (Overshoot, Settling time).
- Maintenance: Parameter changes in the field are configuration changes. Handle them under Change control and keep the documented values current.
- Documentation: Service manuals should state which parameters technicians may change, in which range, and how to restore factory values.
Controller tuning vs. controller design
Design chooses the structure (P, PI, PID, cascade, feedforward). Tuning sets the numbers within that structure. Poor structure can't be fixed by tuning alone.