Digisonix, Inc.

Other

Trevor A Laak, Jr

Mark C Allie

Steven R Popovich

Larry J Eriksson

Brian M Finn

Douglas E Melton

Jerry J Trantow

David W Kapsos, Jr

Douglas G Pedersen

James E Allard

An adaptive passive acoustic attenuation system implements control techniques to facilitate practical use of adaptive passive acoustic attenuation in industrial and commercial applications. The system includes multiple banks of multiple adjustable tuners that are used to passively attenuate an acoustic disturbance (e.g. a tone) propagating through an acoustic plant. All of the tuners in one of the banks are contemporaneously adjusted during an adaptation scan while the tuners in the other banks remain stationary. The process is then carried out for the other banks of adjustable tuners. The number of adjustable tuners per bank is chosen so that adaptation scans of the tuners in the respective bank create observable changes in acoustic levels to enable adaptation. Multiple sets of multiple banks of adjustable tuners can be provided to attenuate multiple disturbances propagating through the acoustic plant. Signals from error sensors are filtered and processed to account for acoustic energy in the plane wave mode as well as higher order modes. Adaptation accuracy is improved by a double scan technique, and by accounting for time-varying acoustic disturbances. Mechanical malfunctioning of the adjustable tuners is reduced by an exercising technique, and the control model implements a lock-out scheme for mechanically malfunctioning tuners.

Adaptive passive acoustic attenuation system

Coherence optimization is provided in an active adaptive control system. The adaptive control model (16) has a model input (18) receiving a reference signal (8) from a reference input transducer (4), an error input (20) receiving an error signal (14) from an error transducer (10), and a model output (22) outputting a correction signal (24) to an output transducer (26) to introduce a control signal matching the system input signal (6) to minimize the error at the error input. Coherence in the system is determined, and a coherence filter (27; 28; 29) is provided according to the determined coherence. Preferably, one or more of the error signal (14), reference signal (8) and correction signal (24) is coherence filtered.

Coherence optimized active adaptive control system

A system that facilitates the development and operation of active sound or vibration control systems, especially for those not skilled in computer programming. The system facilitates the development of developing active sound or vibration control systems implementing an adaptive control model. In particular, the system has a software collection containing control system software that implements an adaptive control model which can be programmed on an electronic controller to actively control sound or vibration. The system also has a user interface that prompts the user to enter information pertaining to the control system being developed so that the electronic controller can implement an adaptive control model in accordance with the information entered by the user.

System for developing and operating an active sound and vibration

In an active adaptive attenuation system having a main model, a second adaptive filter model is provided having an input from the output of the main model, and an output supplied to the input of the main model. A copy of the main model has an input from the input to the second model and an output supplied to a multiplier multiplying the error signal and the output of the copy and supplying the resultant product as a weight update signal to the second model.

Active attenuation system with on-line modeling of feedback path

An acoustic system (20) includes a model reference (22) having a selectably programmable response, and an active model (24) including in combination an acoustic path (26) and an adaptive filter (28) such that the combination of the acoustic path (26) and the adaptive filter (28) adaptively models the model reference (22) such that the combined response of the acoustic path (26) and the adaptive filter (28) provides an active model response matching the response of the model reference (22).

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Madison, WI, United States of America

Trevor A Laak, Jr