Integrated fuzzy logic controller with continuous processing

A new fuzzy logic controller, which is suitable for a system with analog input and output, has been implemented in a monolithic form. It employs an architecture where time sweeping of variables allows continuous evaluation of fuzzy inferences and defuzzification without having to discretize input and output variables using A/D and D/A converters. Direct processing of the analog input signal is used to obtain the corresponding crisp value; the digital portion is used only for programmability. The controller can handle 3 inputs, 1 output, and 25 programmable fuzzy rules. The test IC chips were fabricated using 0.7 /spl mu/m CMOS technology. A control problem of stabilizing a ping-pong ball in a tube with a controllable air flow has been successfully demonstrated.