A PD-type self-tuning FLC for second-order systems with dead-time

This paper deals with the design of a fuzzy PD controller (FPDC) with dynamic gain through a non-fuzzy self-tuning scheme. The output scaling factor (SF) of the proposed non-fuzzy self-tuning based FPDC, termed as NFST-FPDC, is modified on-line by a gain updating factor (β), which depends on the normalized change of error of the controlled variable (Δe_N) and its number of fuzzy partitions. The proposed scheme is tested for a wide variety of second-order linear, nonlinear, integrating, and non-minimum phase systems with dead-time under both set-point change and load disturbance. Detailed performance comparison with a well known self-tuning fuzzy PD controller (STFPDC) reported in the leading literature is provided with respect to a number of performance indices. Unlike, STFPDC, which uses 49 expert´s defined self-tuning fuzzy rules our NFST-FPDC uses a single parametric relation. Simulation results justify the effectiveness of the proposed scheme.