A novel implementation of fuzzy logic controller using new meet operation

The authors have proposed a simple fuzzy logic hardware controller, in which the weighted average operation can be simplified to the weighted sum operation by introducing a new meet operation (M. Sasaki and F. Ueno, 1991). However, the characteristics of the edges of the fuzzy membership functions in the controller vary with temperature and processing variations. To overcome this limitation, we propose two bias circuits and a variable current mirror. The circuits can improve the characteristics of the controller not to influence temperature and processing variations without sacrificing the circuit simplicity. The high performance of the improved hardware controller, for example 200 ns total delay time, 1.0% maximum operation error, 3.0 V low supply voltage and 150 μW low power dissipation per one rule, was confirmed by SPICE simulation