Active vibration control by a smart auxiliary mass damper equipped with a fiber Bragg grating sensor

This paper presents the results of a key activity of a large research project (MESEMA) in the aeronautics field, funded by the European Community under the Sixth Framework Programme, namely the modeling and control of a magnetostrictive actuator to be used for broadband vibration and noise control. The developed auxiliary mass damper was designed in order to meet the demanding requirements of the application at hand, especially in terms of weight reduction and force capability. The specifications were successfully satisfied using a resonant intertial actuator concept based on a nonlinear mechanism for amplifying the seismic mass displacement. The nonlinearities of the actuator highly affect the problem of its adoption within the active feedback control system devoted to vibration and noise reduction of the controlled structure. In order to overcome the limitation and negative effects of these nonlinearities within the main control system, the actuator was equipped with an optical sensor based on a fiber Bragg grating (FBG). The FBG was used within a low-level control loop based on a model-following control algorithm, aimed at imposing a desired linear behavior to the actuator itself. The controlled actuator was used to design an optimal vibration controller. Experimental results show the effectiveness of the approach both for the low-level and the high-level control loops.