The implementation of low cost Fuzzy Logic Controller for PLC TSX 37-21

Fuzzy logic controller (FLC) is one of popular control algorithms. This paper proposes the implementation of FLC for PLC TSX 37-21. This PLC has additional plug-in called PL7Fuz but user has to buy it separately. The proposed idea was implemented to control the speed of DC motor. FLC is designed with 2 inputs and 1 output (5 labels for each input/output). For simplicity, the output membership function uses singleton type. The input membership functions use triangle and trapezoid types. For this PLC can be programmed with several methods, the structured text method was chosen. Although the performance of the system in the presence of disturbance was not satisfied, the system worked well under normal condition. The FLC system is not general so the tuning process is difficult. It is interesting to continue this project to generate the general purpose FLC system.