Synthesis of operational transconductance amplifier-based analog fuzzy functional blocks and its application

A synthesis of analog fuzzy functional blocks (a complementary membership function circuit, a maximum circuit, a complementary maximum circuit, and a defuzzifier circuit) based on operational transconductance amplifiers (OTA's) is presented. The complementary membership function circuit and the maximum circuit are synthesized from the formulations using bounded-difference operations. The defuzzifier circuit is synthesized as the follower-aggregation circuit composed of multiplier-type OTA's, SPICE simulations showed that the proposed fuzzy functional blocks feature high-speed operations and low power consumption. The complementary membership function circuit, the maximum circuit, and the complementary maximum circuit were built with discrete components and commercially available OTA's, and the performances of these circuits were confirmed by experiments. As an application, a singleton fuzzy controller with 3/spl times/3 rules is synthesized using the proposed circuits. The simulation of this controller showed that the inference speed of the order of 15 MRPS (rules per second) is easily realizable.<
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