Beschreibung:
<jats:p>Adaptive feed-forward algorithms have been successfully applied in the active control of sound and vibration. However, the actual mechanisms of control inherent in the technique remain an area of much interest. The main objective of this research is to study the dynamic characteristics of a feed-forward controlled system. The structure is assumed to be subjected to a harmonic input excitation, and the system controlled by another force. The controller is defined by minimizing the mean-square value of an error sensor signal. The error sensor is an accelerometer mounted on the structure or a microphone placed in the acoustic field for the active control of vibration or sound radiated, respectively. An entirely new mathematical approach to predict the dynamics of the controlled system is presented, which shows that the controlled system effectively has new eigenproperties. They are a function of the control force and error sensor locations, and independent of the input disturbance. Numerical examples demonstrate the formulation. These results are also corroborated experimentally using a feed-forward controller implemented on a TMS320C20 DSP processor. [Work supported by ONR.]</jats:p>