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Self-tuning control with regularized RLS algorithm for vibration cancellation of a circular plate

Leniowska L., Kos P.

Archives of Acoustics

2009

Vol. 34, No. 4

613-624

The self-tuning control assumes that the vibrating system is unknown and the controller procedure has the ability to identify the process and to update the necessary control law. Such an algorithm provides the relevant regulator parameters according to the obtained parametric object model. The algorithm can be described as a combination of the following two procedures: the online identification and the computation of the controller parameters. Nearly all of the identification procedures are related to the Least Squares (LS) estimate of a model output. Classified as an ill-posed problem, it implies that the obtained solution is potentially very sensitive to the data perturbations. In order to avoid such problems, the regularized version of the RLS method has been considered in this paper. By solving the linear system of equations with a non-singular Sylvester matrix, the formulas for the unknown coefficients of the considered PID-type controller structure have been obtained. The results of the tests and simulations for the circular plate vibration cancellation have been also included.

Influence of phase correction on the acoustic impedance of circular planar sources

Kos P., Leniowska L.

Archives of Acoustics

2007

Vol. 32, No. 4

895--901

In this work, the influence of velocity distribution phase correction on the acoustic impedance of a circular source located in an infinite baffle is analyzed. It has been observed that by turning back a velocity distribution phase by modifying the radiating surface shape in a special way, obtaining a more coherent acoustic radiation is possible. This problem has been analyzed during earlier investigations, with attention focused on the directivity of some acoustic sources [1]. The aim of this paper is to calculate the acoustic impedance which allows the examination of such a "phase correction" effect on the acoustic radiation of the considered sound sources. The result was achieved by numerical calculation with the use of Hankel representation of the acoustic impedance.