Parallel structure of fuzzy PID controller under different paradigms

The development of fuzzy PID controllers need the construction of a three-dimensional rule base, which makes its design very complicated in terms of rule base structure and implementation of inferencing. Due to these disadvantages, design of a two input fuzzy PID controller structures become an interest which is a combination of two term fuzzy logic controllers i.e. fuzzy PI and fuzzy PD controllers. Analytical structures for parallel structure configuration of fuzzy proportional-integral-derivative (PID) controllers are derived using minimum triangular norm, different combinations of triangular co-norms (maximum, drastic sum), different inference methods (such as Mamdani minimum, Larsen product, drastic product, bounded product and standard sequence) and center-of-sum denazification method. This work also discuss about how to derive the analytical structures for Parallel structure of fuzzy PID controller (i.e., Fuzzy PI + Fuzzy PD controller) under different classes. A series of computer simulations are pursued and are included to demonstrate the effectiveness of the parallel structure fuzzy PID (FPI + FPD) controller and fuzzy PID controller over the conventional controller applied to time-delay systems, non-linear and complex systems.