TOWARDS THE IC IMPLEMENTATION OF ADAPTIVE FUZZY-SYSTEMS

The required building blocks of CMOS fuzzy chips capable of performing as adaptive fuzzy systems are described in this paper. The building, blocks are designed with mixed-signal current-mode cells that contain low-resolution A/D and D/A converters based on current mirrors. These cells provide the chip with an analog-digital programming interface. T hey also perform as computing elements of the fuzzy inference engine t hat calculate the output signal in either analog or digital formats, t hus easing communication of the chip with digital processing environme nts and analog actuators. Experimental results of a 9-rule prototype i ntegrated in a 2.4-mu m CMOS process are included. It has a digital in terface to program the antecedents and consequents and a mixed-signal output interface. The proposed design approach enables the CMOS realiz ation of low-cost and high-inference fuzzy systems able to cope with c omplex processes through adaptation. This is illustrated with simulate d results of an application to the on-line identification of a nonline ar dynamical plant.