Feedback Active Noise Control with Online Secondary-Path Modeling
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Solution Overview
Problem
Conventional feedback active noise control systems with online secondary-path modeling face challenges such as high auxiliary noise contribution to residual noise, poor independence between the controller and online secondary-path modeling module, and difficulty in handling sudden changes in the secondary path or target noise, which restricts noise suppression performance and practical application.
Innovation Solution
A feedback active noise control system with online secondary-path modeling that separates narrowband and broadband components from residual noise to adjust auxiliary noise amplitude and improve module independence, using real-time energy changes to monitor and re-initialize system coefficients, enhancing dynamic performance and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If online secondary-path modeling is implemented in feedback active noise control system, then the system can estimate time-varying secondary path in real time and adapt to complex application occasions, but the auxiliary noise contribution to residual noise increases, which restricts noise suppression performance
Solution Approach 1:
The patent segments the residual noise into narrowband component and broadband component using linear prediction. The narrowband component is used for controller updates while the broadband component is used for online secondary-path modeling. This segmentation allows independent optimization of each module's update process, reducing the harmful effect of auxiliary noise on overall noise suppression performance while maintaining adaptability to time-varying conditions.
2Adaptability or versatility
If residual noise is used for updating both controller and online secondary-path modeling module, then the system can adapt to changes, but the broadband component restricts controller update speed and narrowband component restricts convergence rate of online secondary-path modeling
Solution Approach 1:
The patent divides residual noise into narrowband and broadband components through linear prediction, assigning each component to a specific module: narrowband for controller updates and broadband for online secondary-path modeling. This segmentation removes the mutual restrictions between modules, enabling the controller to update at higher speeds while the online modeling converges efficiently, thus improving overall system responsiveness and adaptability.
Solution Approach 2:
The patent introduces an intermediary mechanism (linear prediction-based component separation) that processes residual noise before distributing it to different modules. This intermediary filtering allows each module to receive optimized input signals tailored to its specific requirements, improving both update speed and convergence rate without sacrificing adaptability.
3Adaptability or versatility
If conventional online secondary-path modeling methods are used, then the system can track time-varying secondary path, but the independence between controller and online secondary-path modeling module is poor, affecting dynamic performance
Solution Approach 1:
The patent segments the residual noise signal into distinct frequency components and assigns them to different functional modules. This creates independent input channels for the controller and online secondary-path modeling module, establishing clear functional boundaries between modules. The segmentation approach maintains excellent tracking capability of time-varying secondary paths while achieving module independence, thereby improving dynamic performance without increasing system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Significantly reduces auxiliary noise contribution, improves noise reduction performance, and enhances the system's ability to handle sudden changes, achieving better dynamic performance and robustness in complex noise reduction scenarios without requiring a reference sensor, thus reducing hardware costs and physical space requirements.
Implementation Method 1
Active noise control (ANC) achieves the purpose of noise reduction by generating a secondary noise with the same amplitude and opposite phase with respect to target noise by means of the principle of destructive interference of acoustic waves
Data Source
AI summary
The present disclosure presents a feedback active noise control system and strategy with online secondary-path modeling, and belongs to the technical field of active noise control. The linear prediction subsystem takes the residual noise as its input and separates the remaining sinusoidal noise from the broadband noise. The remaining sinusoidal noise is used effectively not only to update the controller but also to scale the auxiliary noise, while the broadband noise serves as a desired input of online secondary-path modeling subsystem. In this way, the coupling between the controller and the online secondary-path modeling subsystem is significantly mitigated, leading to both faster convergence and improved noise reduction performance. A practical scheme for refreshing the entire system is also developed to enhance its robustness against even abrupt changes with the secondary path or the primary noise. The present disclosure enhances the applicability of feedback active noise control in practical applications.