Saeed Olyaee - Nano-photonics and Optoelectronics Research Laboratory (NORLab), Faculty of Electrical and Computer Engineering, Shahid Rajaee Teacher Training University, Lavizan, ۱۶۷۸۸-۱۵۸۱۱, Tehran, Iran
Reza Ebrahimpour - Brain & Intelligent Systems Research Lab (BISLab), Faculty of Electrical and Computer Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran
Somayeh Esfandeh - Nano-photonics and Optoelectronics Research Laboratory (NORLab), Faculty of Electrical and Computer Engineering, Shahid Rajaee Teacher Training University, Lavizan, ۱۶۷۸۸-۱۵۸۱۱, Tehran, Iran

In this paper, a method for determination of refractive index in membrane of fuel cell on the basis of three-longitudinal-mode laser heterodyne interferometer is presented. The optical path difference between the target and reference paths is fixed and phase shift is then calculated in terms of refractive index shift. The measurement accuracy of this system is limited by nonlinearity error. In this study, nonlinearity error is modeled by multi-layer perceptrons (MLPs) and stacked generalization method (Stacking), using two learning methods; back propagation (BP) and genetic algorithm. Training neural networks with genetic algorithm improves modeling of nonlinearity error in this system. In the proposed technique, a real code version of genetic algorithm is used. Parameters and genetic operators are set and designed accurately. The results indicate that the nonlinearity error can be effectively modeled by training the stacking with the genetic algorithm which has minimum mean square error (MSE).

Fuel cell,Genetic algorithm,Heterodyne interferometer,Multi-layer perceptrons,Nonlinearity error,,Refractive index,Stacked generalization