Accommodating MR Damper Dynamics for Control of Large Scale Structural Systems
The focus of this paper is to propose three new control strategies for an advanced damping system utilizing magnetorheological (MR) dampers and investigate their effectiveness, and to validate real-time hybrid testing (RTHT) using an MR damper and the proposed controllers. The first proposed controller, Over-Driven Clipped Optimal Control (ODCOC), combines a clipped-optimal control with over-driven and back-driven current control. The second proposed controller, a displacement feedback-based simple passive controller, is proposed to reduce the computational and sensing cost for seismic mitigation. The third proposed controller is a polynomial-based strategy for semi-active control. Using genetic algorithms, the coefficients of a 4th order polynomial equations about velocity and displacement responses are determined for the best control efficiency. Using an illustrative numerical example, a four story prototype structure equipped with MR dampers is used to evaluate the performance of the proposed control algorithms, compared to alternative control strategies (including clipped-optimal control and others). Via simulations of the structure using various seismic ground motions, reductions in various parameters are examined and compared for all control algorithms. The second part of the study focuses on a RTHT involving the MR damper as an experimental substructure, and the prototype structure designated as the analytical substructure. After performing the RTHT for a suite of controllers using one ground motion, a comparison is made between the results of the numerical simulation performed earlier and the results from the RTHT. The studies discussed herein demonstrate that the proposed control strategies are effective at optimizing damper and structural performance and practically implementable for active and semi-active structural control applications. In addition, the RTHT strategy is validated as an effective method of testing, based upon a response comparison.
Researchers should cite this work as follows:
Anthony Joseph Friedman; Jianqiu Zhang; Brian Phillips; Zhaoshuo Jiang; Anil Agrawal; Shirley Dyke; James Ricles; Bill Spencer; Richard Sause; Richard Christenson (2010), "Accommodating MR Damper Dynamics for Control of Large Scale Structural Systems," http://nees.org/resources/674.