Time-Domain Rule-Condensed Fuzzy Control for Base-Isolated Structures Using MRD: Control Design and Performance Evaluation

Abstract

This paper proposes a Time-domain Rule-Condensed Fuzzy Control (TRC-FC) strategy for base-isolated structures with magnetorheological dampers (MRDs) to resolve the inherent tradeoff between base displacement and floor acceleration. Through time-domain analysis of high-performance control algorithms, three empirical rules are extracted: low current at displacement endpoints, medium current from origin to endpoint, and high current from endpoint to origin. These rules are embedded into a compact fuzzy controller with only two inputs and three rules, optimized via a multiobjective genetic algorithm. Evaluated under seven seismic excitations and two isolation periods, TRC-FC consistently outperforms or matches passive-on, H 2 / Linear Quadratic Gaussian ( H 2 / LQG ), filter-based pseudo-negative-stiffness (FPNS), skyhook, and state-of-the-art conceptual multiobjective fuzzy genetic control (CMFGC) in simultaneously suppressing both responses. The controller achieves smooth, phase-dependent force modulation without abrupt transitions. The proposed rule-extraction framework is generalizable to other semiactive devices. TRC-FC provides a simple, interpretable, and high-performance solution to a long-standing control challenge.