Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: An Optimal Sensitivity-Enhancing Feedback Control Approach via Eigenstructure Assignment for Structural Damage Identification J. Vib. Acoust. 2007;129(6):771-783. doi:10.1115/1.2748476 Figure Legend: Damage identification results using noise-contaminated natural frequencies of the open-loop system, ad hoc closed-loop systems and optimal closed-loop systems, respectively. The noise level is v=2.0%. Black bars: actual stiffness reduction; Striped bars: prediction using noise-contaminated natural frequencies of the open-loop system; gray bars: prediction using noise-contaminated natural frequencies of the ad hoc closed-loop systems; checkered bars: prediction using noise-contaminated natural frequencies of the optimal closed-loop systems.