Proximity Compensation for Vehicle Remote Microphone ANC
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Solution Overview
Problem
Existing remote microphone technologies in vehicles assume a fixed location between physical and virtual microphones, which becomes inaccurate when occupants adjust their seats, affecting ANC system performance and stability.
Innovation Solution
A system that determines a transfer function based on the occupant's seat position using a lookup table of premeasured positions and interpolation, allowing for accurate error signal generation at a virtual microphone location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed transfer function is used between physical and virtual microphones, then the system structure is simple, but the ANC performance deteriorates when seat position changes
Solution Approach 1:
The patent implements dynamic adjustment of transfer functions based on detected seat positions. The system stores multiple transfer functions corresponding to different seat positions and selects the appropriate transfer function dynamically, transforming the static fixed transfer function approach into a dynamic adaptive approach that maintains ANC performance across varying seat positions.
Solution Approach 2:
The patent changes the parameter of transfer function selection based on seat position detection. By detecting the seat position and selecting or interpolating the corresponding transfer function, the system adapts the acoustic parameters to match the actual occupant position, resolving the contradiction between structural simplicity and performance reliability.
2Reliability
If additional hardware like head tracking devices is added to track occupant position, then the ANC performance is improved, but the device complexity increases
Solution Approach 1:
The patent utilizes the existing seat position detection capability of the vehicle's own systems to determine occupant position for ANC purposes. By leveraging the vehicle's existing sensors and control systems that already track seat positions for other functions, the system achieves accurate ANC adaptation without adding dedicated head tracking hardware, thus maintaining performance while avoiding increased complexity.
Solution Approach 2:
The patent makes the existing seat position detection system serve dual purposes: both the vehicle's existing control functions and the ANC system. This multi-functional use of existing hardware allows the ANC system to achieve accurate occupant tracking without requiring separate dedicated sensors or devices.
3Reliability
If the transfer function is adjusted dynamically based on seat position, then the ANC performance is maintained, but the processing complexity increases
Solution Approach 1:
The patent pre-calculates and stores multiple transfer functions corresponding to different seat positions before actual ANC operation. By performing the complex transfer function calculations in advance and storing them in a lookup table, the system avoids real-time complex computations during ANC operation, reducing processing complexity while maintaining performance.
Solution Approach 2:
The patent implements a dynamic selection or interpolation mechanism that chooses from pre-calculated transfer functions based on detected seat positions. This approach transforms the problem from requiring real-time complex calculations to a simpler dynamic selection or interpolation process, maintaining cancellation performance while reducing processing complexity.
Data Source
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AI summary
A remote microphone system for a vehicle may include at least one physical microphone arranged within a vehicle cabin configured to generate an error signal at a virtual microphone location within the vehicle, a database configured to maintain a look up table of premeasured seat positions and associated transfer functions, and a processor. The processor may be configured to receive a seat position indicative of a seat location within the vehicle, and apply a transfer function associated with the premeasured position to a primary noise signal of the at least one physical microphone to generate the error signal.