ASIC Implementation of Fuzzy Controllers: A Sampled-Analog Approach

Sampled-analog circuit techniques are exploited in the design of an ASIC fuzzy controller. A circuit library comprising seven different subcircuits has been developed for this purpose. Any expert system of piecewise linear input membership functions, conjunctive rules and singleton output classes can be implemented with this library. The circuits have been implemented in 1.2μ CMOS. Test results indicate excellent linearity and accuracy in full 5V rail-to-rail operation in all these circuits. Based on this library, a controller of 4 inputs, 2 outputs and 16 rules of 51 antecedent terms has been integrated in 1.76mm², and found fully functional.