ABSTRACTThe systematic design of me

ABSTRACTThe systematic design of membership functions (MPS) for the fuzy logic control (FLC) of a variable speedrefrigeration system (VSRS) is presented in this paper to reduce trial and error as well as dependence on expertknowledge. In particular, the influence of MFs on the error and error change rate of controlled variables isinvestigated in detail to verify the validity of the designed MFs. To this end, the range of MFs obtained based onthe control accuracy and experimental data for the static and dynamic states of the VSRS were used as thecriterion values. Two different values from the criterion were then used to compare the control performancethrough simulations and experiments. Some simulations and real experiments for the VSRS were conducted toverify the validity of the designed MFs. The experimental results showed good agreement with the simulationresults. The error change rate and sampling time strongly affected the control performance of the VSRS in thetransient state. Moreover, the desired control accuracy at steady-state, an esential element in the design spe-cifications, was successfully achieved using the proposed approach. The suggested method can be applied usingthe control accuracy and simple experimental results from the static and dynamic states of the target systemwithout depending on iterative work when designing MFs, which will be helpful for beginners.