A simplified yet effective fuzzy logic controller for chemical ship tanker

Abstract

This paper proposes a simplified yet effective control scheme to design a fuzzy logic controller (FLC) for the ship tanker. The proposed method exploits the feature of signed distance method for reducing the conventional two-input FLC (CFLC) into a piecewise linear single input FLC (PWL-FLC). It has been shown that the proposed FLC has a similar structure to the CFLC, exhibiting analogous control performance. However, the main features of the proposed method are the absence of fuzzification, rule inference and defuzzification processes that are essential for CFLC implementation. The proposed PWL-FLC could be easily programmed into a low cost microcontroller using just a look-up table. To authenticate its effectiveness, the control algorithm has been implemented using the marine system simulator in Matlab/Simulink ® platform. The result signifies that both the PWL-FLC and CFLC results in identical functioning performance; however, the former requires least possible tuning effort and its execution time is in the orders of three magnitudes less than its conventional counterpart.