General optimization procedure of the Hedge-algebras controller for controlling dynamic systems

This study aims to investigate a general optimization procedure of the Hedge-algebras controller (HAC) for controlling dynamic systems. Based on the analysis of factors affecting the control efficiency of HAC, the optimization problem is established following a multi-objective approach. When optimizing HAC, the design variables contain tuning coefficients of control rules, selections of linguistic terms of each rule in the rule base, fuzziness measure parameters of linguistic variables, and variations of the reference range of state and control variables. In which the proposed tuning coefficients have been improved compared with the previous study. In particular, a new inference method is proposed based on the shape/interpolation function of the finite element method. A three-story building structure subjected to earthquake loads is used in the simulation as a case study to demonstrate the effectiveness of the proposed approach. Research results in the present work show that the proposed procedure is general and can be utilized to control different dynamic systems. Moreover, as mentioned above, a large number of the design variables will cause a significant variation in objective functions. It means that the optimum performance is improved compared to optimal cases of individual design variables.