Critic-based fuzzy neurocontroller unit in SISO control loop. The NFC block is the neurofuzzy controller block described in Appendix A1 (See the “Supplemental Data” tab for this paper on the ASME Digital Collection.) and are the tracking error critic signal and control effort critic signal, which are functions of error () and control effort (), respectively. and are actual output and reference position signals. The structure of the NFC block is shown in Fig. A1.