Fuzzy logic base extremum seeking control system

The paper presents a fuzzy logic base seeking control system intended for objects with an extremum (peak) point. The system includes a perturbation signal generator and a fuzzy logic controller for changing the object´s input coordinates. In addition, there is a perturbation signal parameters improvement adaptation subsystem. This subsystem also contains a fuzzy logic controller. There are recommendations for choosing and calculating the system´s main parameters. These parameters are chosen and calculated for two types of processes: a seeking process, which searches for the extremum point; a keeping process that holds the object´s output as close as possible to this point. The system was modeled for one, two and three-dimensional input objects by the Matlab program package. Seeking and keeping process trajectories for various objects are also presented. This was realized on a standard PLC platform using blocks from a fuzzy logic library.