A novel NF-GMDH-IFL and its application to identification and prediction of nonlinear systems

The neurofuzzy GMDH with a feedback loop (NF-GMDH-FL) is presented, based on NF-GMDH and GMDH-FL. The feedback loop of NF-GMDH-FL are investigated and improved in this paper. The neuro fuzzy GMDH with an improved feedback loop (NF-GMDH-IFL) is developed, in which the redundant combinations and computations are discarded. NF-GMDH-IFL has faster training speed and less training time than NF-GMDH-FL. For the convenience of comparison, NF-GMDH, NF-GMDH-FL and NF-GMDH-IFL are applied to two examples, respectively. The simulations show that the capability of NF-GMDH-IFL is better than NF-GMDH and NF-GMDH-FL. Furthermore, the enormous time and memory are saved in NF-GMDH-IFL. The identification and prediction performance for nonlinear systems is observably improved.