Multi-objective optimal fuzzy logic controller for nonlinear building-MR damper system

This paper focuses on the benchmark control problem for seismically excited nonlinear buildings and reports the application of a semi-active control scheme to the 20-story benchmark building using magnetorheological (MR) damping technology. As the fuzzy logic control systems have been applied effectively in various fields, a multi-objective optimal fuzzy logic control system has been proposed in this paper to manage the required voltage of MR dampers. Nondimensionalized peak floor acceleration index from building response category, and ductility index from building damage category, have been considered as the two objective functions to be minimized. All the rule-bases, MFs and scaling factors are tuned well through a recursive optimization algorithm using a Pareto optimal solution, namely NSGAII. The optimization procedure has been done by consideration of 10 various earthquakes in order to provide a more robust controller. The proposed semi active intelligent control scheme satisfies the control constraints and is tabulated according to the evaluation criteria provided by the benchmark problems for comparison with other schemes. Finally, performance of the proposed control system has been found to be better than the other schemes.