Design of a fully programmable analog interval type-2 triangular/trapezoidal fuzzifier

In this paper, analog implementation of a fully programmable Interval Type-2 (IT2) fuzzifier is presented. This fuzzifier operates in current mode and provides triangular, trapezoidal, S and Z-shape Interval Type-2 membership functions precisely by means of just one Type-1 fuzzifier and a Type-2 Generator circuit. In this circuit, shapes of upper and lower membership functions could be adjusted separately and they may have different shapes. The amount of Footprint of Uncertainty (FOU), slope, height and width of generated Interval Type-2 membership functions are fully programmable and each of these properties has the ability to be tuned easily and independently. Hence this circuit is suitable for use as fuzzifier block in Interval Type-2 fuzzy logic controllers (IT2FLC). Simulation results in HSPICE using 4M2P TSMC 0.35μm CMOS technology shows, the power consumption of proposed circuit with supply voltage of 3.3V is 657μW and it occupies an area about 0.01mm².