Patent ID: 6449369
Filing Date: 2002-09-10
Classification: G10K,H04R

Abstract:
Active vibration attenuation device of the type comprising:a framework subject to vibration to be attenuated: first vibration sensor means, arranged on the framework in a first predetermined geometric relationship with respect to said framework; vibration actuator means, arranged on the framework in proximity to the first sensor means; and filtering means comprising at least an input linked to the first sensor means and an output linked to the actuator means, the filtering means being configured to generate active attenuation of the vibration on the framework; second vibration sensor means, arranged on the framework in a second predetermined geometric relationship with respect to said framework; and summation means possessing a first input, a second input, and an output linked to the actuator means; the filtering means comprising: nonadaptive-type feedback filtering means possessing an input linked to the first sensor means and an output linked to the first input of the summation means, and suitable for generating nonadaptive active attenuation of the vibration on the framework, without generating instability in a first frequency band; means for measuring, in advance of operating the device in a hybrid active vibration attenuation mode, in the presence of the feedback filtering means, the transfer function between the actuator means and the first sensor means; adaptive-type feedforward filtering means comprising a first input linked to the second sensor means, a second input linked to the first sensor means, and an output linked to the second input of the summation means; the filtering coefficients of the feedforward filtering means being adapted in real time according to an algorithm chosen to minimize the energy of the types of vibration which are picked up by the first sensor means as a function of the energy of the types of vibration which are picked up by the second sensor means, and of the thus previously measured transfer function measured in advance of operating the device in a hybrid active vibration attenuation mode, which makes it possible to linearize the feedback attenuation throughout a second frequency band, to accelerate the convergence of the minimization algorithm, and to enhance the robustness of the feedforward filtering means.