This paper presents a pseudo-equivalence of digital fuzzy PID controllers with linear PID controllers in the continuous time domain. Transfer functions and equivalence relations between controller’s parameters are obtained for the common structures of the fuzzy PID controllers. The pseudo-equivalence is made using a graphic analytical analysis based on the input-output transfer characteristics ...

Most of the recent research in the design of fuzzy controllers has been centered on automatic techniques using expert’s input-output data. The majority of these techniques rely on the use of Takagi-Sugeno type controllers and fuzzy-neural-network [3-5,11], fuzzy clustering and fuzzy partition approaches [1,2,6,7]. These controllers, however, are not fully-linguistic and the use of neural-networ...

| This paper investigates the possibilities for applications of genetic algorithms to tuning and optimizing fuzzy controllers, or even to generate fuzzy controllers automatically. There are various ad{hoc approaches to use genetic algorithms for the design of fuzzy controllers, which already indicated good results. However, there is a need for systematic techniques that take the properties of f...

This paper deals with the simplest fuzzy PI controllers under various defuzzification methods. The various simplest fuzzy PI controllers consist of two triangular input fuzzy sets and three triangular output fuzzy sets on the universe of discourse of input and output variables, respectively, linear control rules, intersection T-norm, Lukasiewicz and Zadeh OR T-conorms, and any valid inference m...

This paper analyses coupled control of a nonlinear, time-varying plant. Uncoupled and coupled direct adaptive controllers, based on fuzzy logics, are synthesized to control the water level and the air pressure in a closed tank. The satisfactory efficiency of the controllers is experimentally demonstrated running the plant under the different working conditions. Coupled fuzzy controllers are com...

A novel approach to designing stable fuzzy controllers with perception-based information using fuzzy-arithmetic-based Lyapunov synthesis in the frame of computing with words (CW) is presented. It is shown that a set of conventional fuzzy control rules can be derived from the perception-based information using the standard-fuzzy-arithmetic-based Lyapunov synthesis approach. On the other hand, a ...

We proposed a fuzzy control scheme to implement the cycle-to-cycle control for restoring swing phase of gait using functional electrical stimulation (FES). We designed two fuzzy controllers for the biceps femoris short head (BFS) and the vastus muscles to control flexion and extension of the knee joint during the swing phase. Control capabilities of the designed fuzzy controllers were tested an...

The synthesis of a control system includes both the controller selection and the adjustment of its parameters. In some cases, the type of controller might be more complex or more general, like PID instead PI or PD, to improve the control system performance. In all cases, the tuning problem must be satisfactorily solved. On the other hand, Fuzzy Control has made possible the establishment of int...

Different types of controlling methods are used in switched mode dc-dc converters and the controller which is simple and of low cost is always in demand. The different controllers used are PI controller, PID controller and Fuzzy logic controller. PI and PID controllers do not give good performance in non linear conditions. Fuzzy logic controller is a non linear controller which do not need exac...

This paper presents the comparison of tracking control performance of fuzzy PI Controller with fuzzy PID and conventional PID controllers. Fuzzy PI controller and Fuzzy PID controller composes of Mamdani type fuzzy controllers and parameters are adjusted to meet the desired control system performances both in transient state and steady state. Computer simulations are done for controlling the ti...