Fuzzy Logic Control on FPGA Using LabVIEW

We implement a fuzzy logic control algorithm on a Nexys 3 FPGA board that uses coding look-up tables on VHDL which is generated by an application developed in LabVIEW. The algorithm used in this work is based on alpha-levels. This technique reduces execution time and simplifies VHDL programming. In addition, it is possible to use any shape of membership sets, although only triangular trapezoidal and gaussian are tested. Also, LabVIEW application helps in verifying each block of the system through boolean, numeric and graph indicators. Further, using look-up tables avoids the necessity of VHDL coded while loops. The system uses a max-min Mamdani inference mechanism. In Nexys 3 FPGA board COSAA defuzzification method [2] is implemented. Crisp output values are compared with those obtained with MATLAB Fuzzy Logic Tool Box. Results have very little variation.