An Efficient Self-Organizing Deep Fuzzy Neural Network for Nonlinear System Modeling

A fuzzy neural network (FNN) is an effective learning system that combines neural network and fuzzy logic, which has achieved great success in nonlinear system modeling. However, when the input is practical complex data with external disturbance, the existing FNN cannot extract effective input features sufficiently, leading to unsatisfactory performances in learning speed and accuracy. It also fails to achieve a better generalization capability because of its fixed structure size (the number of rule neurons). In this article, an efficient self-organizing FNN (SOFNN) with incremental deep pretraining (IDPT), called IDPT-SOFNN, is developed to overcome these shortcomings. First, IDPT is designed to extract effective features and consider them as the input of the SOFNN. Different from the existing pretraining, the self-growing structure of IDPT improves pretraining efficiency with a more compact structure. Second, the SOFNN can dynamically add and delete neurons according to the current error and error-reduction rate. In this case, it can obtain better modeling performance with a more compact structure as well. Third, as a novel hybrid model with the cascade dual-self-organizing algorithm, the IDPT-SOFNN combines the advantage of IDPT and SOFNN. Moreover, the convergence and stability are analyzed. Finally, simulation studies and comparisons demonstrate that the proposed IDPT-SOFNN has better performances than its peers in learning speed, accuracy, and generalization capability.