关键词：控制器；现场可编程门阵列；快速模糊控制；对数域
摘 要：Defuzzification has long been a bottleneck for fast implementations of fuzzy logic controllers, due to the large number of computationally expensive multiplication and division operations that are required. In this paper, we report a high-speed fuzzy inferential system based on log-domain arithmetic, which only requires addition, subtraction and multiplexing operations. The system is implemented on a Xilinx Virtex-II FPGA with a processing speed of 67.6 MFLIPS and a maximum combinational path delay of 4.2 ns. A pipelined version of the controller is also implemented, which achieves a speed of 248.7 MFLIPS. Although a small approximation error is introduced, software simulation and hardware implementation on FPGA confirm high similarity of the outputs for typical and log-domain control surfaces and a number of second-order plants.