Active vibration control design and experiment of the flexible plate with mixed uncertainty via μ-synthesis

A new kind of mu-synthesis controller design method of mixed uncertainty model was presented and proved from test results based on one flexible plate with which was bonded with piezoelectric actuators and sensors. Firstly, the MIMO transfer function model and the state space model of the vibration system were identified by the multivariable frequency-domain identification theory and the ERA method. On the base of the two models, the canonical uncertainty block diagonal matrix extraction method of modal parameter perturbation was designed by the means of eigenvalue decomposition of the test model system matrix and linear fraction transformation, at the same time the residual modal was expressed by the high band filter, then the mu-synthesis controller solution procedure was established which considered the mixed uncertainty of the test model. The active vibration control tests of the plate with three addition masses indicated, compared with the open-loop system, the attenuation time of initial disturbance was shortened 40 s, the noise reduction of random disturbance was increased nearly 4 dB.