Vehicle ANC Reference Signal Mixing for Transient Noise Control
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Solution Overview
Problem
Existing ANC systems struggle to effectively cancel noise sources that lack correlated reference signals and transient noise sources, leading to degraded performance and audible artifacts when adapting to new or changing noise conditions in modern vehicles.
Innovation Solution
The method involves receiving a plurality of noise reference signals from a plurality of noise signals, including signals from one or more accelerometers and one or more additional noise sources, estimating one or more vehicle operating parameters, and dynamically selecting and adjusting reference signals based on vehicle operating conditions, and dynamically selecting and adjusting reference signals based on vehicle operating parameters, and dynamically selecting and adjusting reference signals based on vehicle operating conditions, and dynamically selecting and adjusting reference signals based on vehicle operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If more reference inputs are added to accommodate every potential noise source, then the ANC system can cancel a wider range of noise sources, but it exceeds the computational resources and memory limitations of embedded automotive processors
Solution Approach 1:
The patent segments the reference signal processing by dividing multiple reference inputs into different processing paths. Instead of processing all reference signals uniformly, the system segments them based on their correlation characteristics and noise source types, allowing selective processing that reduces computational load while maintaining coverage of multiple noise sources
Solution Approach 2:
The patent implements dynamic reference signal selection where the system adaptively chooses which reference signals to use based on current vehicle operating conditions and detected noise characteristics. This dynamic approach allows the ANC system to adjust its reference signal set in real-time, maintaining effective noise cancellation across different scenarios without requiring all possible reference inputs to be processed simultaneously
2Adaptability or versatility
If the adaptive filter continues to adapt after a transient noise source turns off, then it can track changing noise conditions, but it generates audible artifacts where the ANC system itself generates noise
Solution Approach 1:
The patent applies preliminary action by detecting when a transient noise source is about to turn off or has turned off, and proactively adjusting the reference signal selection before the adaptive filter completes its adaptation cycle. This prevents the filter from generating mismatched anti-noise signals that would create audible artifacts, while still maintaining the capability to quickly adapt when noise sources reappear
Solution Approach 2:
The patent uses feedback mechanisms to monitor the output of the adaptive filter and detect audible artifacts. When artifacts are detected, the system feedback-adjusts the reference signal selection to eliminate the mismatched anti-noise generation. This closed-loop approach ensures that the ANC system maintains adaptability while preventing harmful audible artifacts from reaching the cabin
Data Source
AI summary
Systems and methods are provided for enhancing the performance and adaptability of active noise cancellation (ANC) systems in vehicles by dynamically adjusting reference signal gains and combining reference signals based on vehicle operating conditions. A plurality of noise reference signals are acquired from sources like accelerometers, acoustic vehicle alerting system (AVAS) speakers, LiDAR sensors, seat motors, and HVAC blowers. Vehicle parameters such as speed, seat position, and blower speed are estimated to retrieve dynamic gain values from lookup tables. The dynamic gains are applied to the respective noise reference signals to generate gain-adjusted reference signals. The gain-adjusted signals are mixed using configurable mixing gains to produce a reduced set of combined reference signals provided to an adaptive filter. This approach enables the ANC system to effectively cancel a wider variety of noise sources, including transient sources, while preventing noise boosting artifacts when sources turn off.