RULE BASE OPTIMIZATION OF FUZZY CONTROLLER FOR AUTOMATIC CONTROL SYSTEM OF FLOATING DOCK DRAFT

Keywords: floating dock; automatic control system of draft; fuzzy controller; rule base; optimization.

Abstract

The article presents the automatic control system of the floating dock draft on the basis of a fuzzy controller, which ensures draft control of the floating dock on the feedback principl.. Since the floating dock is the object of control without autostabilization, so as a fuzzy controller of floating dock draft is used fuzzy PD-controller of the Mamdani type. Since the use of the integral component of the error in the control process will only reduce the quality metrics. Moreover, in this paper, a fuzzy controller with five triangular linguistic terms for each of the three input and output variables are used. Parameters of the membership functions of the linguistic terms of the input and output variables of the fuzzy PD-controller are pre-optimized based on the desired transition control processes of the draft using gradient parametric optimization methods. To improve the proposed fuzzy PD-controller control in terms of reducing the processing time, the optimization of the rules base of the fuzzy PD-controller on the basis of rules reduction is performed. The procedure for structural optimization of the rule base of the fuzzy PD-controller consists of identifying the degree of influence of the rules on the output signal of the fuzzy PD- controller, constructing the appropriate ranked number of rules for the reduction of this parameter, as well as the exclusion from the rule base of those rules, the effect of which on the formation of a control signal is irrelevant. In turn, the reduction of the base rules of the fuzzy PD-controller, based on the assessment of the impact of each rule on the control process, has allowed to reduce the total number of rules from 25 to 15 without degrading the quality performance of the docking operations of the floating dock. This allows to significantly simplify the software and hardware implementation of the synthesized fuzzy PD-controller in the automatic control system of the floating dock draft. The simulation of the transients of the fuzzy control system of the floating dock draft and the analysis of the quality indices of the developed fuzzy control system shows the feasibility of using the developed fuzzy PD- controller with the optimized rule base.

Author Biographies

Юрій Пантелійович Кондратенко, Petro Mohyla Black Sea National University
doctor tech. sciences, professor
Олексій Валерійович Козлов, National University of Shipbuilding named after Admiral Makarov

Ph.D., Associate Professor

Андрій Миколайович, Топалов, National University of Shipbuilding named after Admiral Makarov

lecturer

Published
2019-04-19
How to Cite
Кондратенко, Ю., Козлов, О., & Топалов, А. (2019). RULE BASE OPTIMIZATION OF FUZZY CONTROLLER FOR AUTOMATIC CONTROL SYSTEM OF FLOATING DOCK DRAFT. Electrotechnic and Computer Systems, (30(106), 169-177. https://doi.org/10.15276/eltecs.30.106.2019.18
Section
Automation of control processes