Vehicle Noise Reduction System Using Averaged Error Signals
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Solution Overview
Problem
Existing noise reduction systems in vehicles are limited by their sensitivity to user head movements, requiring frequent relocation of noise reduction areas and placing a high computational load on control units, which reduces their effectiveness and increases costs.
Innovation Solution
A noise reduction system that uses a controller with a reference sensor, sound generator, and a monitor-microphone array, implementing a virtual sensing algorithm with an averaging unit to calculate an average error signal across multiple virtual microphone positions, dynamically adjusting parameters to minimize the average error signal and expand the quiet zone, while reducing computational load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single virtual microphone position is used for noise reduction, then the noise reduction effectiveness at that specific position is high, but the system becomes sensitive to user head movements and the quiet zone is limited
Solution Approach 1:
The patent divides the noise reduction task into multiple segments by implementing multiple virtual microphones at different positions within the noise reduction area. Each virtual microphone independently processes noise cancellation for its specific location, allowing the system to maintain effectiveness across a broader spatial region and adapt to user head movements without sacrificing noise reduction performance at any individual position.
2Adaptability or versatility
If multiple virtual microphone positions are used to expand the quiet zone, then the flexibility with user head movements is improved, but the computational load on the control unit increases significantly
Solution Approach 1:
The patent merges the processing of multiple virtual microphone signals by using a single physical microphone array to capture acoustic information that is then computationally distributed to multiple virtual microphone positions. This approach allows the system to expand the quiet zone and improve adaptability to head movements while sharing the computational load across the control unit, rather than requiring completely independent processing channels for each virtual microphone.
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
The system effectively enlarges the quiet zone, providing more flexibility with user head movements and reducing computational burden, achieving efficient noise reduction with lower costs by averaging error signals across multiple positions.
Implementation Method 1
The anti-noise is superimposed on the undesired background noise in that the background noise is reduced or almost completely eliminated in a quiet zone by means of destructive interference.
Implementation Method 2
a microphone for detecting the background noise of a noise source
Implementation Method 3
the monitor-microphone array being disposed adjacent to the noise reduction area and being configured to pick up background noise emitted by the noise source and anti-noise emitted by the sound generator
Data Source
AI summary
A noise reduction system for actively compensating background noise in a passenger transport area of a vehicle. The system includes an averaging unit configured to calculate an average error signal, which is indicative of a difference between a background noise and an anti-noise at more than one position in a noise reduction area and a dynamic adjustment unit, configured to update parameters of the anti-noise unit based on the average error signal and so as to minimize the average error signal.