Abstract
For controlling the vibration field of a structure by using a proper weighting on the control actuators, one needs a distribution of vibration response created by excitation forces injected from the actuators before or during the control actions. However, considering the time drift of physical properties and environment-related conditions of the controlled structure and actuators, such information would cause the error in control and might result a spill-over eventually. Therefore, when the control is to be performed in frequent machine on-off condition, we need a precise and quick method for estimating the vibration transfer functions at every time just before the control. To this end, we adopt the iterative variation method to quickly approximate the solution by utilizing some known responses by a preliminary measurement. The precision and speed in obtaining the solution depend heavily on the number of unknown coefficients and iterations. A thin rectangular panel with unclear boundary conditions, 400x900 mm2 in size, and subject to a single point excitation is selected as the test example. Comparing the estimated and measured responses, in which 171 known responses are used as initial data, the error is found to be less than 6% for an average for 3600 points.