Acoustic Injection Array for Dynamic Noise Cancellation
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Solution Overview
Problem
Current noise cancellation technologies, such as Active Noise Control (ANC), are ineffective against rapidly changing audio signals and high-frequency omnidirectional noise, and they often introduce additional noise or consume power, limiting their dynamic noise cancellation capabilities.
Innovation Solution
The development of acoustic quiet zones through the injection of cancellation signals using directional and high-fidelity acoustic pick-up devices, distributed acoustic emitters, and multiple sensors, which dynamically update amplitude and phase weightings to minimize undesired acoustic signals, creating a quiet zone by injecting processed noise waveforms to cancel out selected noises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If Active Noise Control (ANC) is used to cancel undesired noises, then noise cancellation capability is improved, but the system introduces additional noise and consumes power
Solution Approach 1:
The patent captures the undesired acoustic signals themselves and uses them as the source material for generating cancellation waves. By injecting processed versions of the actual noise signals back into the environment, the system converts the harmful noise into a beneficial cancellation tool, eliminating the need for separate sensor-based detection and transformation processes that introduce additional noise.
Solution Approach 2:
The system creates accurate copies of the undesired acoustic signals by capturing them directly and processing them through the injection array. These copied signals are then manipulated in amplitude and phase to generate precise cancellation waves, avoiding the noise introduction that occurs in traditional ANC systems that must transform sensor data into cancellation signals.
2Object-affected harmful factors
If traditional ANC systems are used, then some noise cancellation is achieved, but they are ineffective against rapidly changing audio signals and high-frequency omnidirectional noise
Solution Approach 1:
The patent implements dynamic adaptation by continuously capturing current noise signals and updating the injection array parameters in real-time. The system dynamically adjusts amplitude and phase weightings based on the actual acoustic environment, enabling it to effectively cancel rapidly changing audio signals and high-frequency omnidirectional noise that static ANC systems cannot handle.
Solution Approach 2:
The system establishes a feedback loop where acoustic sensors continuously monitor the acoustic environment, detect undesired signals, and feed this information back to the injection array for real-time cancellation wave generation. This closed-loop feedback mechanism ensures the system adapts to changing noise conditions and maintains effective cancellation across various frequency ranges and signal types.
3Object-affected harmful factors
If noise cancellation technology is applied, then undesired noises are reduced, but power consumption increases
Solution Approach 1:
The patent extracts only the essential cancellation function from complex ANC systems by directly capturing noise signals and injecting processed versions through a simplified array. This extraction approach eliminates unnecessary power-consuming components and processing steps while maintaining effective noise cancellation, thereby reducing overall power consumption.
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
This approach effectively reduces undesired acoustic signals by up to 25 dB, providing a dynamic and power-efficient solution for mitigating noise in various environments, including cars, aircraft, and enclosed spaces, while preserving desired acoustic signals.
Implementation Method 1
The weightings are referred to as cancellation beam weight vectors (CWVs). These CWVs are used to control the radiation patterns of the acoustic injection array, injecting processed versions of the identified noise signals for cancellation of the undesired acoustic signals over the quiet zone.
Data Source
AI summary
A system for generating and injecting acoustic interference signals to mitigate undesired acoustic noise over a target zone. M pickup sensors pick up acoustic noise signals from one or more noise sources in real time and generate M noise signals, M>1. A beam forming network includes M acoustic beam forming modules to process the M noise signals respectively and generate N acoustic interference signals. N acoustic injectors condition, amplify and inject the N acoustic interference signals over the target zone, N>1. Each of the M acoustic beam forming modules includes a 1-to-N distribution network to transform a respective one of the M noise signals into N signals, and N finite-impulse-response filters to perform amplitude and phase weighting on the respective N signals and generate N intermediate signals which are combined respectively with corresponding intermediate signals generated by remaining M−1 acoustic beam forming modules to generate the N acoustic interference signals.