Adaptive neuro fuzzy inference system

An adaptive neuro-fuzzy inference system or adaptive network-based fuzzy inference system (ANFIS) is a kind of artificial neural network that is based on Takagi–Sugeno fuzzy inference system, a class of fuzzy models introduced by Tomohiro Takagi and Michio Sugeno for system identification and control.^[1] The technique was developed in the early 1990s.^[2][3] Since it integrates both neural networks and fuzzy logic principles, it has potential to capture the benefits of both in a single framework.

Its inference system corresponds to a set of fuzzy IF–THEN rules that have learning capability to approximate nonlinear functions.^[4] Hence, ANFIS is considered to be a universal estimator.^[5] For using the ANFIS in a more efficient and optimal way, one can use the best parameters obtained by genetic algorithm.^[6][7] It has uses in intelligent situational aware energy management system.^[8]

It is possible to identify two parts in the network structure, namely premise and consequence parts. In more details, the architecture is composed by five layers.

1. The first layer takes the input values and determines the membership functions belonging to them. It is commonly called fuzzification layer. The membership degrees of each function are computed by using the premise parameter set, namely {a,b,c}.
2. The second layer is responsible of generating the firing strengths for the rules. Due to its task, the second layer is denoted as "rule layer".
3. The role of the third layer is to normalize the computed firing strengths, by dividing each value for the total firing strength.
4. The fourth layer takes as input the normalized values and the consequence parameter set {p,q,r}.
5. The values returned by this layer are the defuzzificated ones and those values are passed to the last layer to return the final output.^[9]