Self-tuning fractional order PI~λD~μ controller based on extremum seeking approach

摘要

Fractional PID (PI~λD~μ) controllers are not commonly used in industry when compared to classical PID controllers. The main reason is that the fractional controller parameters tuning remains an open problem. In this work we propose to generalise a classical PID tuning method based on extremum seeking (ES) approach to PI~λD~μ control parameters tuning in order to achieve optimal performance. ES is a non-model-based method which searches online for the parameters that minimise a cost function which is representative of the controller's performance. The main advantage of this method is that it can be applied to a plant in which there is no knowledge of the model. Comparative simulation examples show the effectiveness of the proposed strategy for fractional order PI~λD~μ tuning.