FPGA based implementation of a Fuzzy Neural Network modular architecture for embedded systems

Abstract

This paper presents a FPGA based approach for a modular architecture of Fuzzy Neural Networks (FNN) to embed with easily different topologies set up. The project is based on a Takagi - Hayashi (T-H) method for the construction and tuning of fuzzy rules, this is commonly referred as neural network driven fuzzy reasoning. The proposed architecture approach consists of two main configurable modules: a Multilayer Perceptron - MLP with sigmoidal activation function that composes the first module to determine a Fuzzy membership function; the second employs an MLP with pure linear activation function to define the consequents. The DSPBuilder <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> software along the Simulink <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> is used to connect, set and synthesize the Fuzzy Neural Network desired. Other hardware components employed in the architecture proposed cooperate to the system modularity. The system was tested and validated through a control problem and an interpolation problem. Several papers proposed different hardware architecture to implement hybrid systems by using Fuzzy logic and Neural Network. However, there is no approach with this specific neural network driven fuzzy reasoning by T-H method and the aim to be embedded. The Self-Organizing Map (SOM) and Levenberg-Marquardt backpropagation were used to train the FNN proposed off-line.