Glossary · Control theory and process control
Adaptive control
Also known as: Self-adjusting control
German: Adaptive Regelung
In control engineering, adaptive control is a control strategy in which the controller adjusts its own parameters during operation to follow changes in the dynamics of the controlled system, for example changing gain, load or dead time.
- Control theory
- Process industry
In one sentence
Adaptive control adjusts controller parameters during operation so the loop keeps performing when the process dynamics change.
Example
A web tension controller on a winder adapts its gain as the roll diameter grows, because the same torque change has a smaller effect on a large roll.
How it applies
- Engineering: Adaptive schemes range from simple gain scheduling (parameter tables selected by an operating point) to model-reference and self-tuning controllers that estimate the process model online. Define the limits within which parameters may change, so a faulty measurement cannot drive the loop into instability.
- Commissioning: Test the loop at several operating points, not only at the nominal one, and record which adaptation mechanism is active and how fast it reacts.
- Documentation: Describe for operators and service staff which parameters adapt automatically, how to freeze adaptation, and what the Human-machine interface (HMI) shows when adaptation is disabled or saturated. Record the Operating assumption behind the adaptation law in the design documentation.
Adaptive control vs. robust control
Robust control uses one fixed controller designed to tolerate a known range of model uncertainty. Adaptive control changes the controller itself as the process changes. Robust designs are easier to verify; adaptive designs can cover wider ranges but need monitoring of the adaptation.