A new PI+D type hierarchical fuzzy logic controller

In this study, a fuzzy logic controller that uses the integral action in a hierarchical manner is considered. The output of a conventional fuzzy logic controller that uses error and derivative of error as input variables is improved by using the second derivative of error. An important feature of the proposed controller is its simple structure. The simulations are performed on linear and nonlinear plants. It is shown that the new structure provides an improvement in system performance without inserting too much complexity.