00000cab a22000003a 4500 UP-99796217609532553 Buklod 20231007234346.0 m |o d | ta 101104s xx d | ||r ||||| || DENGII eng Bao-Gang Hu A systematic study of fuzzy PID controllers-function-based evaluation approach. pp. 699-712 A function-based evaluation approach is proposed for a systematic study of fuzzy proportional-integral-derivative (PID)-like controllers. This approach is applied for deriving process-independent design guidelines from addressing two issues: simplicity and nonlinearity. To examine the simplicity of fuzzy PID controllers, we conclude that direct-action controllers exhibit simpler design properties than gain-scheduling controllers. Then, we evaluate the inference structures of direct-action controllers in five criteria: control-action composition, input coupling, gain dependency, gain-role change, and rule/parameter growth. Three types of fuzzy PID controllers, using one-, two- and three-input inference structures, are analyzed. The results, according to the criteria, demonstrate some shortcomings in Mamdani's two-input controllers. For keeping the simplicity feature like a linear PID controller, a one-input fuzzy PID controller with "one-to-three" mapping inference engine is recommended. We discuss three evaluation approaches in a nonlinear approximation study: function-estimation-based, generalization-capability-based and nonlinearity-variation-based approximations. The study focuses on the last approach. A nonlinearity evaluation is then performed for several one-input fuzzy PID controllers based on two measures: nonlinearity variation index and linearity approximation index. Using these quantitative indices, one can make a reasonable selection of fuzzy reasoning mechanisms and membership functions without requiring any process information. From the study we observed that the Zadeh-Mamdani's "max-min-gravity" scheme produces the highest score in terms of nonlinearity variations, which is superior to other schemes, such as Mizumoto's "product-sum-gravity" and "Takagi-Sugeno-Kang" schemes Control-action. Direct-action controllers. Function-based evaluation approach. Function-estimation-based approximations. Fuzzy proportional-integral-derivative-like controllers. Fuzzy reasoning mechanisms. Gain dependency. Gain-role change. Gain-scheduling controllers. Generalization-capability-based approximations. Input coupling. Linearity approximation index. Max-min-gravity scheme. Membership functions. Nonlinear approximation. Nonlinearity. Nonlinearity variation index. Nonlinearity-variation-based approximations. One-input fuzzy PID controller. One-input inference structures. One-to-three mapping inference engine. Process-independent design guidelines. Quantitative indices. Rule/parameter growth. Simplicity. Three-input inference structures. Two-input inference structures. IEEE Transactions on fuzzy systems 9, 5 (2001). FO UPD DENG-II Article