CAD TOOL FOR IMPLEMENTATION OF FUZZY CONTROLLERS ON FPGAs

In this paper, a computer-aided design (CAD) tool for implementing fuzzy controllers on field-programmable gate arrays (FPGAs) is presented. The developed tool reduces the fuzzy controller to a set of Boolean equations. The output file of the developed tool, which contains the set of Boolean equations, is in an acceptable format for the FPGA development system. The FPGA development system then generates the necessary code to program the FPGA chip. Therefore, the developed design tool together with the FPGA development system represent a complete design automation system for fuzzy controllers. Using this system, a fuzzy controller with speed of 50 M fuzzy logic inferences per second (FLIPS) is realized.     

Overcurrent relay on a FPGA chip

A new hardware approach for implementing overcurrent relays is presented in this paper. An overcurrent relay is implemented on a field programmable gate array (FPGA) chip (Xilinx's XC3020-50-PC84C). The hardware design of the overcurrent relay is based on a three-stage pipelined architecture. A relationship that describes the time-current characteristics of the relay in terms of the clock frequency of the chip is developed.