Vehicle Active Noise Cancellation With Selective Transfer Updates
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Solution Overview
Problem
Existing high-frequency active noise cancellation (HF-ANC) systems in vehicles face challenges due to computational and memory limitations from the need to measure, store, and update numerous head-related impulse response (IR) sets, exacerbated by the coupling effect between occupants' head positions, which increases the number of required IR sets.
Innovation Solution
A dynamic path management strategy that selectively updates only a subset of transfer functions in response to detected head movement, reducing the computational complexity and memory demands by maintaining most IR sets static, while efficiently managing high-frequency noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If head-related impulse responses are updated for all possible head position combinations of occupants, then high-frequency noise cancellation accuracy is improved, but computational complexity and memory requirements increase significantly
Solution Approach 1:
The patent segments the set of transfer functions into multiple subsets, where each subset corresponds to a specific head position range. Instead of updating all transfer functions for all possible head positions, the system divides the head position space into discrete zones and maintains separate transfer function subsets for each zone. This segmentation allows the system to update only the relevant subset when head movement is detected, significantly reducing computational complexity while maintaining noise cancellation accuracy within each segment.
Solution Approach 2:
The patent applies partial action by updating only a subset of transfer functions rather than the complete set. When head movement exceeding a threshold is detected, the system identifies which specific subset of transfer functions corresponds to the new head position range and updates only those functions. This partial update approach maintains sufficient noise cancellation performance while avoiding the excessive computational burden of updating all possible transfer functions.
2Reliability
If head-related impulse responses are stored for all possible head position combinations, then high-frequency noise cancellation performance is maintained, but memory requirements become prohibitive
Solution Approach 1:
The patent segments the complete set of transfer functions into multiple smaller subsets stored in memory, where each subset corresponds to a specific head position range. This segmentation reduces the memory burden at any given time, as only the relevant subset needs to be loaded and maintained in active memory. The system can switch between subsets as head position changes, maintaining performance reliability without requiring prohibitive total memory capacity.
Solution Approach 2:
The patent stores and maintains only a partial set of transfer functions in active memory at any given time, rather than all possible combinations. By maintaining multiple smaller subsets that can be swapped based on detected head position, the system achieves the necessary noise cancellation performance with significantly reduced memory requirements compared to storing all possible head position combinations simultaneously.
3Measurement precision
If transfer functions are updated frequently in response to head movement, then noise cancellation accuracy is maintained, but processing time and energy consumption increase
Solution Approach 1:
The patent updates only a partial subset of transfer functions when head movement is detected, rather than performing a complete update of all transfer functions. The system monitors head position and, when movement exceeds a threshold, identifies and updates only the specific subset corresponding to the new position range. This selective update approach maintains noise cancellation accuracy while significantly reducing processing time and energy consumption compared to frequent complete updates.
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 strategy effectively reduces high-frequency noise with reduced computational complexity and memory usage, maintaining accurate noise cancellation performance by updating only a subset of transfer functions based on occupant position changes.
Implementation Method 1
Active noise control is used to generate sound waves that destructively interfere with undesired sound waves. The destructively interfering sound waves may be produced by a transducer, such as a loudspeaker, to combine with the undesired sound waves.
Implementation Method 2
A camera or other sensor may be used to track a head position of one or more occupants of the vehicle.
Data Source
AI summary
Methods and systems are disclosed for an audio system for a vehicle system. In one example, a noise cancellation system includes a vehicle having a plurality of speakers and a plurality of microphones, a plurality of sensors, and a controller. The controller includes instructions stored on non-transitory memory that when executed cause the controller to generate a noise cancellation signal using a set of head-related impulse responses for the plurality of speakers and the plurality of microphones based on a head position of one or more occupants and a plurality of transfer functions, including to selectively update only a subset of the plurality of transfer functions responsive to the plurality of sensors detecting head movement greater than a threshold.