Method and device for hybrid active attenuation of vibration, particularly of mechanical, acoustic or similar vibration

Method of active vibration attenuation, particularly of acoustic vibration, of the type comprising the following stages:

• a) providing a framework subject to vibration to be attenuated;
• b) providing first vibration sensor means, arranged on the framework in a first predetermined geometric relationship with respect to said framework;
• c) providing vibration actuator means, arranged on the framework in proximity to the first sensor means;
• d) providing filtering means comprising at least an input linked to the first sensor means and an output;
• e) configuring the filtering means so as to generate active attenuation of the vibration on the framework;
• f) providing second vibration sensor means, arranged on the framework in a second predetermined relationship;
• g) Providing summation means possessing a first input, a second input, and an output linked to the actuator means;
• characterized in that it further comprises the following stages:
• h) providing 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 configuring the said feedback filtering means so as to generate nonadaptive-type active attenuation of the vibration on the framework, without generating instability in a first frequency band;
• i) measuring, in advance of operating the device in a hybrid active vibration attenuation mode;
• and in the presence of the feedback filtering means, the transfer function between the actuator means and the first sensor means;
• j) providing nonadaptive-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 mean;
• k) adapting the filtering coefficients of the feedforward filtering means 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 the 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 which is wider than the first frequency band, to accelerate the convergence of the minimization algorithm, and to enhance the robustness of the feedforward filtering means.

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;
• and
• wherein the first frequency band is from about 0 Hz to about 600 Hz and the second frequency band is from about 0 Hz to about 1500 Hz.

Method of active vibration attenuation, particularly of acoustic vibration, of the type comprising the following stages:

• a) providing a framework subject to vibration to be attenuated;
• b) providing first vibration sensor means, arranged on the framework in a first predetermined geometric relationship with respect to said framework;
• c) providing vibration actuator means, arranged on the framework in proximity to the first sensor means;
• d) providing filtering means comprising at least an input linked to the first sensor means and an output;
• e) configuring the filtering means so as to generate active attenuation of the vibration on the framework;
• f) providing second vibration sensor means, arranged on the framework in a second predetermined relationship;
• g) Providing summation means possessing a first input, a second input, and an output linked to the actuator means;
• characterized in that it further comprises the following stages:
• h) providing 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 configuring the said feedback filtering means so as to generate nonadaptive-type active attenuation of the vibration on the framework, without generating instability in a first frequency band;
• i) measuring, in advance of operating the device in a hybrid active vibration attenuation mode and in the presence of the feedback filtering means, the transfer function between the actuator means and the first sensor means;
• j) providing nonadaptive-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;
• k) adapting the filtering coefficients of the feedforward filtering means 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 the previously measured transfer function measured in advance of operating the device in a hybrid active vibration attenuation mode;
• and
• pre-amplifying a signal from the first vibration sensor means and inputting the amplified signal to the nonadaptive-type feedback filtering means;
• which makes it possible to linearize the feedback attenuation throughout a second frequency band which is wider than the first frequency band, to accelerate the convergence of the minimization algorithm, and to enhance the robustness of the feedforward filtering means;
• and wherein the first frequency band is from about 0 Hz to about 600 Hz and the second frequency band is from about 0 Hz to about 1500 Hz.