AbstractThe objective of this work is to experimentally examine some practical issues relating to the reliability and performance of active structural control systems. Using the newly constructed shaking table in the Department of Structural Mechanics at the University of Pavia, experiments were conducted employing an actively controlled, three story test structure. A DC‐motor based active mass driver system was used as the active control device. AnH2/LQG controller based on acceleration feedback is applied to the system. The first objective of this work is to demonstrate the efficacy of the acceleration feedback control strategy. Next, two experiments are conducted with the goal of investigating fault tolerant control system design. In the first case, the occurence of a sensor failure is simulated experimentally, and the resulting controlled performance and robustness characteristics are assessed. The second set of tests is to evaluate the ability of the controller to reduce the structural responses when reduced information is available for control action determination. Both of these issues are important practical concerns in the design and implementation of a structural control syste