Vehicle Headrest Active Noise Control With Adaptive Feedback
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Solution Overview
Problem
Existing noise-canceling headrests for vehicle seats only provide partial noise cancellation, failing to effectively eliminate engine and rolling noise, which affects the comfort of vehicle occupants.
Innovation Solution
A noise-canceling headrest with a central part and side wings, equipped with microphones, speakers, and a signal processing circuit that generates a noise correction signal to improve noise cancellation by using a feedback loop and adaptive filtering, creating a personal sound zone for each user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional sound insulation is used, then the structure is simple and easy to manufacture, but the noise reduction effect is insufficient (only about 20dB)
Solution Approach 1:
The patent implements an active noise control system with a feedback loop that includes a microphone to detect residual noise, a signal processing circuit to analyze the error signal and update the noise correction function, and a loudspeaker to emit corrected sound waves. This closed-loop feedback mechanism continuously optimizes noise cancellation, achieving over 10dB additional noise reduction compared to passive insulation alone.
Solution Approach 2:
The noise control system is designed as a self-contained unit integrated into the headrest, with all necessary components (microphone, loudspeaker, signal processing circuit, audio source reading module) housed within the headrest structure itself. This self-service design enables easy installation in existing vehicles without requiring external system integration.
2Object-affected harmful factors
If a loudspeaker is integrated into the headrest behind the user's head, then the sound can be emitted close to the ears to cancel noise, but the noise cancellation is only partial
Solution Approach 1:
The system employs a microphone positioned in the headrest to detect residual noise that escapes the initial cancellation, feeds this error signal to a signal processing circuit that updates the noise correction function in real-time, and adjusts the loudspeaker output accordingly. This feedback mechanism transforms partial noise cancellation into effective noise control by continuously adapting to changing noise conditions.
Solution Approach 2:
The noise correction function is dynamically updated based on real-time error signals from the microphone, allowing the system to adapt to varying engine noise and road noise conditions. The signal processing circuit continuously modifies the correction parameters, transforming a static noise cancellation system into a dynamic one that responds to changing acoustic environments.
3Object-affected harmful factors
If noise cancellation is improved with additional components, then the noise reduction exceeds 10dB additionally, but the installation complexity increases
Solution Approach 1:
The patent combines multiple functions into a single integrated headrest unit: the loudspeaker for noise cancellation, the microphone for error detection, the signal processing circuit for real-time control, and the audio source reading module for personal audio playback. This merging of components into one self-contained unit simplifies installation in existing vehicles while achieving over 10dB additional noise reduction.
Solution Approach 2:
The headrest system performs multiple functions simultaneously: active noise cancellation in the personal sound zone, personal audio playback through the loudspeaker, and voice signal capture via the microphone. This multi-functionality is achieved within a single integrated structure, making the system versatile and suitable for various vehicle configurations without requiring separate installations for each function.
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
Significantly improves noise reduction by more than 10dB compared to traditional sound insulation, allowing users to enjoy personal audio content or phone calls without disturbing others, while reducing engine and rolling noise effectively.
Implementation Method 1
a signal processing circuit configured to: receive a noise signal from said sensor, and determine a noise correction function taking into account the noise signal, receive an error signal from said microphone, and update the noise correction function, taking into account the error signal, generate a noise correction signal, by applying the noise correction function to the noise signal,generate a control signal to the loudspeaker, by adding the noise correction signal and the audio signal
Implementation Method 2
the headrest further comprising a microphone oriented towards said space
Implementation Method 3
receive an error signal from said microphone, and update the noise correction function, taking into account the error signal
Data Source
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AI summary
Noise-canceling headrest for vehicle seat, comprising a central part (5c) and two lateral parts (5a, 5b), at least one loudspeaker (11a, 11b), a microphone (17a, 17b), an audio source playback module capable of emitting an audio signal to the loudspeaker (11a, 11b), a noise sensor (14a, 14b, 14c), and a signal processing circuit configured to: - receive a noise signal and determine a noise correction function, - receive an error signal from said microphone (17a, 17b), and update the noise correction function, - generate a noise correction signal, by applying the noise correction function to the noise signal, - generate a control signal to the loudspeaker (11a, 11b), by adding the noise correction signal and the audio signal.