Time-delayed decentralized H2/LQG controller for cable-stayed bridge under seismic loading

Abstract

SUMMARY Consistency of real-time data transmission is an important factor in active and semi-active control of structures. Recent advances in wireless sensors and their reliable data communication have attracted many attentions in structural control engineering. Wireless sensors have been also preferred to wire-base types because of problems associated with installing extensive length of coaxial wires. In addition, embedded computing technologies in wireless sensors as local controller reduce size of transferring data and provide stable transmission. However, there are some issues in implementation of wireless connection like communication range and latency. This study presents the feasibility of developing a decentralized controller by using H2/LQG as robust-optimum algorithm in cable-stayed bridge. Because of large scale of structure, the order of model is reduced by using two different reduction methods in finite time and frequency. The controller is developed in centralized and decentralized solutions. The decentralized controller through developing a gradient-based method is designed to efficiently solve system of closed-loop H2 optimization problem. The structural responses in centralized and decentralized solutions are compared with each other under three different earthquake records considering time delay in data transmission. Results indicate that for large-scale bridges with time-delayed data communication issue, H2/LQG controller in decentralized solution gives maximum reduction of response indices in comparison with other strategies. Copyright © 2011 John Wiley & Sons, Ltd.