Active Noise Control Device Using Merged Error Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing active noise control devices for vehicles require complex control and expensive processors due to the need to handle multiple vibration sensors, speakers, and microphones, leading to increased design and component costs.
Innovation Solution
An active noise control device that uses a first adaptive filter to generate a control signal by performing a filtering process on a reference signal, with filter coefficients updated based on error signals from microphones on either side of the vehicle compartment, allowing for noise reduction without the need for multiple microphones at different locations, thereby simplifying control and reducing computational requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple vibration sensors, speakers, and microphones are used to reduce noise, then noise reduction effectiveness is improved, but device complexity and processing cost increase
Solution Approach 1:
The patent combines the error signals from multiple microphones (first and second microphones positioned at different locations) into a single integrated control signal through addition. This merging approach maintains the noise reduction effectiveness of multiple sensors while simplifying the control system by processing a combined signal rather than managing separate control paths for each sensor, thereby reducing device complexity and processing requirements
2Reliability
If multiple vibration sensors, speakers, and microphones are used to reduce noise, then noise reduction effectiveness is improved, but processor cost increases
Solution Approach 1:
The patent merges multiple error signals into a single added error signal that can be processed by a less expensive processor. By combining the signals early in the processing chain and using a single adaptive filter update path, the system maintains effective noise reduction while reducing the computational power (and thus cost) of the required processor
3Reliability
If error signals from multiple microphones are added together, then noise reduction coverage is improved, but computational load increases
Solution Approach 1:
The patent combines error signals from multiple microphones through simple addition to create a single added error signal. This merging operation maintains broad noise reduction coverage by incorporating information from multiple locations while using computationally efficient addition rather than more intensive processing operations, thereby minimizing computational load
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 noise in vehicle compartments while minimizing design and component costs by simplifying control processes and avoiding the need for expensive processors.
Implementation Method 1
a first adaptive filter configured to generate the control signal by performing a filtering process on a reference signal corresponding to the noise
Implementation Method 2
a first error signal acquired by detecting residual noise due to interference between the noise and the canceling sound
Data Source
AI summary
An active noise control device includes a first adaptive filter configured to generate a control signal by performing a filtering process on a reference signal corresponding to noise, and a first filter coefficient updating unit configured to update a filter coefficient of the first adaptive filter based on based on the reference signal and an added error signal acquired by adding a first error signal acquired by detecting residual noise by a first microphone and a second error signal acquired by detecting residual noise by a second microphone.