IMPLEMENTATION OF FUZZY CONTROLLER ON FPGA

Abstract

Fuzzy Logic Control (FLC) systems have emerged as one of the most promising areas for Industrial Application. These systems operate with knowledge represented in a linguistic form (IF-THEN rules) that describes relations which are not precisely known, but those effects are intuitively understood by humans. For industrial application these controllers has been developed either on a personal computer or using microprocessor. In this dissertation FLC has been designed and developed on Field Programmable • Gate Array (FPGA). Very. High Speed Integrated Circuits hardware Description language (VHDL) has been used to develop FLC on FPGA. Error and rate of change in error can be utilized to design any FLC. In this work FLC is designed for an armature control DC motor speed control. Error and change in error in speed has been used as two inputs to FLC. For both the inputs 5 triangular membership function has been selected and coded in VHDL. An algorithm has been developed in VHDL to fuzzifie the crisp digital values of speed error and rate of change of error, rule inference and defuzzification. Sugeno type FLC structure has been used to obtain the controlled output. The controller algorithm developed is synthesized, simulated and implemented on FPGA SPARTAN 3E xc3s500e-4fg320 board. The FLC has been designed using system generator approach. This report discusses in detail the procedure to use hardware co-simulation block which interacts with the FPGA. The results of the FLC implemented on FPGA have been compared with the results obtained using PID and FLC on MATLAB Simulink.