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US 5,633,795 AGranted
Adaptive tonal control system with constrained output and adaptation
AssigneeDigisonix, Inc.
InventorSteven R. Popovich
Life of this patent
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Abstract
An adaptive control system and method for actively canceling tones in an active acoustic attenuation system has an adaptive parameter bank. Adaptation of the adaptive parameter bank can be constrained with respect to the null space of a C model of an auxiliary path (e.g. speaker-error). Alternatively, output from the adaptive parameter bank can be constrained with respect to the effective null space of the C model. The preferred system uses singular value decomposition, normalization, and demodulation to implement the methods of constraining output and adaptation. The invention can eliminate stability and tracking problems associated with over-parameterization.
Claims45
An adaptive tonal control system having a system input and a system output, the adaptive tonal control system comprising:
- a plurality of actuators each receiving a correction signal and outputting a secondary input, the secondary inputs combining with the system input to yield the system output;
- a plurality of error sensors sensing the system output, each error sensor generating an error signal that can be used to update adaptive parameters;
- and
- an adaptive controller that outputs the correction signals, the controller having
- an adaptive parameter bank that outputs a plurality of output signals in accordance with adaptive parameters,
- a C model of a path between the output of the adaptive controller and the error sensors, the C model having an effective range and an effective null space, and
- an output weighting element that inputs the output signals from the parameter bank and weights the output signals to generate correction signals which are constrained to diminish components in the effective null space of the C model.
4 more elements
An adaptive tonal control system having a system input and a system output, the adaptive control system comprising:
- a plurality of actuators each receiving a correction signal and outputting a secondary input, the secondary inputs combining with the system input to yield the system output;
- a plurality of error sensors sensing the system output, each sensor generating an error signal;
- an adaptive controller that outputs the correction signals, the controller having
- an adaptive parameter bank that outputs a plurality of output signals in accordance with the adaptive parameters, the output signals being used to generate the correction signals,
- a C model of a path between the output of the adaptive controller and the error sensors, the C model having an effective range and an effective null space,
- an error weighting element that inputs the error signals from the error sensors and weights the error signals to generate error input signals that are used to update the adaptive parameters in the adaptive parameter bank such that adaptation is constrained to be within the efficiently controlling subspace of the C model.
3 more elements
An adaptive tonal control system having a system input and a system output, the adaptive control system comprising:
- a plurality of actuators, each receiving a correction signal and outputting a secondary input, the secondary inputs combining with the system input to yield the system output;
- a plurality of error sensors sensing the system output, each sensor generating an error signal;
- and
- an adaptive controller that outputs the correction signals and has
- an adaptive parameter bank that inputs a reference signal during sequential sample periods, and outputs a plurality of output signals in accordance with adaptive parameters for each of the sequential sample periods, the output signals being used to generate the correction signals,
- an error weighting element that receives the error signals and outputs a plurality of error input signals,
- a parameter update generator that applies an in-phase demodulation signal and a quadrature demodulation signal to the error input signals for each sample period when generating update signals, and outputs an in-phase update signal and a quadrature update signal that are used to update the adaptive parameters in the adaptive parameter bank.
4 more elements
In an adaptive control system having a system input and a system output, the method of controlling a tone comprising the steps of:
- modeling a path between an output of an adaptive filter controller and one or more error sensors in the system to generate a C path model;
- generating a plurality of output signals;
- weighting the plurality of output signals to yield a plurality of correction signals in which components in the effective null space of the C path model are diminished;
- and
- using the correction signals to provide a secondary input that combines with the system input to yield the system output;
- wherein the components in the effective null space are diminished by nulling components of the correction signals in which .parallel.Cy.sub.n .parallel. is small, where C is a matrix representing the C path model and y.sub.n is a vector representing non-trivial correction signals.
3 more elements
In an adaptive control system having a system input and a system output, a method of controlling a tone comprising the steps of:
- modeling a path between an output of an adaptive controller and one or more error sensors in the system to generate a C path model;
- generating a plurality of output signals in accordance with adaptive parameters;
- using the output signals to provide a secondary input to the system which combines with the system input to yield the system output;
- sensing the system output with error sensors to generate a plurality of error signals;
- weighting the plurality of error signals to yield a plurality of error input signals such that adaptation is constrained with respect to the effective null space of the C model;
- and
- using the error input signals to update the adaptive parameters;
- wherein adaptation is constrained with respect to the effective null space by nulling components of the correction signals in which .parallel.Cy.sub.n .parallel. is small, where C is a matrix representing the C path model and y.sub.n is a vector representing non-trivial correction signals.
5 more elements
A method as recited in claim 31 further comprising the step of:
- weighting the plurality of output signals to yield a plurality of correction signals in which components in the effective null space of the C path model are diminished, and using the correction signals to provide the secondary input that combines with the system input to yield the system output.
In an adaptive control system having a system input and a system output, a method of controlling a tone comprising to steps of:
- inputting a reference signal for sequential sample periods to an adaptive controller;
- outputting a plurality of correction signals from the adaptive controller which are used to generate secondary inputs that combine with the system input to yield the system output;
- sensing the system output with error sensors to generate a plurality of error signals;
- modeling a path between the output of the adaptive controller and the error sensors to generate a C path model;
- weighting the error signals to generate a plurality of error input signals;
- applying an in-phase demodulation signal and a quadrature demodulation signal to the error input signals every sample period to generate an in-phase update signal and a quadrature update signal for sample periods when the system is generating update signals;
- using the in-phase and the quadrature update signals to update the adaptive parameters.
4 more elements
An adaptive tonal control system having a system input and a system output, the adaptive tonal control system comprising:
- a plurality of actuators each receiving a correction signal and outputting a secondary input, the secondary inputs combining with the system input to yield the system output;
- a plurality of error sensors sensing the system output, each error sensor generating an error signal that can be used to update adaptive parameters;
- and
- an adaptive controller that outputs the correction signals, the controller having
- an adaptive parameter bank that outputs a plurality of output signals in accordance with adaptive parameters,
- a C model of a path between the output of the adaptive controller and the error sensors, and
- an output weighting element that inputs the output signals from the parameter bank and weights the output signals to generate correction signals, wherein the output weighting element depends on the C model.
4 more elements
In an adaptive control system having a system input and a system output, the method of controlling a tone comprising the steps of:
- modeling a path between an output of an adaptive filter controller and one or more error sensors in the system to generate a C path model;
- generating a plurality of output signals;
- processing the plurality of output signals to yield a plurality of correction signals in such a manner that the processing depends on the C model so that the system converges to a stable solution;
- and
- using the correction signals to provide a secondary input that combines with the system input to yield the system output;
- wherein the output signals are generated by:
- processing an in-phase reference signal with an in-phase scaling vector Y.sub.R to generate a first plurality of signals;
- processing the in-phase reference signal with a quadrature scaling vector Y.sub.I to generate a second plurality of output signals;
- processing a quadrature reference signal with the in-phase scaling vector Y.sub.R to generate a third plurality of output signals;
- and
- processing the quadrature reference signal with the quadrature scaling vector Y.sub.I to generate a fourth plurality of output signals.
8 more elements
An adaptive tonal control system having a system input and a system output, the adaptive tonal control system comprising:
- a plurality of actuators each receiving a correction signal and outputting a secondary input, the secondary inputs combining with the system input to yield the system output;
- a plurality of error sensors sensing the system output, each error sensor generating an error signal that can be used to update adaptive parameters;
- and
- an adaptive controller that outputs the correction signals, the controller having
- an adaptive parameter bank that outputs a plurality of output signals in accordance with adaptive parameters,
- a C model of a path between the output of the adaptive controller and the error sensors, the C model having an effective range and an effective null space, and
- an output weighting element that inputs the output signals from the parameter bank and weights the output signals to generate correction signals which are constrained such that the correction signals are orthogonal to components in the effective null space of the C model.
4 more elements
Dependencies are inferred from the claim text.