Helmet ANC Mounting Plate for Wind Noise Attenuation
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Solution Overview
Problem
Existing helmets struggle to effectively attenuate wind noise while allowing important sound information to be heard, and integrating active noise cancellation systems is cumbersome, requiring structural changes or additional weight and size.
Innovation Solution
A mounting plate with a loudspeaker and reference microphones integrated into the helmet's recess, forming an acoustic chamber, which simplifies installation and ensures good acoustic coupling and minimizes feedback, using an ANC control system to generate antiphase sound waves for noise cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If passive sound insulating material is added to the helmet, then wind noise attenuation is improved, but helmet weight and size increase
Solution Approach 1:
The patent replaces passive mechanical sound insulation materials with an active noise cancellation system that uses electronic signal processing. The system employs microphones to detect wind noise, a controller to generate antiphase cancellation signals, and speakers to emit these signals, thereby eliminating the need for heavy passive insulation materials while achieving effective wind noise attenuation.
Solution Approach 2:
The patent changes the approach from static passive insulation to dynamic active noise cancellation by altering the frequency and phase parameters of sound waves. The system actively modifies sound wave characteristics through real-time signal processing, enabling selective attenuation of unwanted wind noise frequencies while preserving useful sound information, thus avoiding the need for bulky insulation materials.
2Object-affected harmful factors
If passive sound insulating material is added to the helmet, then wind noise attenuation is improved, but useful sound information in mid- to high frequencies is attenuated
Solution Approach 1:
The patent applies local quality by selectively targeting specific frequency bands for attenuation. The active noise cancellation system is configured to primarily attenuate low-frequency wind noise while preserving mid- to high-frequency sound information. This is achieved through frequency-selective signal processing that locally applies cancellation only to unwanted noise frequencies, allowing the helmet to maintain clarity of useful sounds like traffic and communication.
Solution Approach 2:
The system changes the frequency response characteristics by implementing frequency-selective noise cancellation. The controller analyzes the spectral content of wind noise and generates cancellation signals targeted at specific frequency ranges where wind noise predominates, while leaving other frequency bands relatively unaffected. This parameter-based approach ensures that useful sound information in mid- to high frequencies is preserved while achieving effective wind noise reduction.
3Object-affected harmful factors
If an active noise cancellation system is integrated into the helmet, then noise cancellation effectiveness is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies universality by designing the active noise cancellation system to serve multiple functions within the helmet. The same hardware components (microphones, speakers, controller) are used for both noise cancellation and communication functions, allowing the system to provide wind noise attenuation while maintaining compatibility with existing helmet designs. This multi-functionality approach reduces overall system complexity and manufacturing costs compared to dedicated single-purpose systems.
Solution Approach 2:
The patent implements preliminary action by pre-configuring the active noise cancellation system during helmet manufacturing. The microphones, speakers, and controller are pre-installed and calibrated in the helmet structure, allowing the noise cancellation functionality to be ready for use without requiring complex post-manufacturing assembly or configuration. This preliminary integration simplifies the overall manufacturing process and reduces costs compared to after-market additions.
4Object-affected harmful factors
If an active noise cancellation system is retrofitted to existing helmets, then noise cancellation is achieved, but structural modifications are required
Solution Approach 1:
The patent applies segmentation by dividing the active noise cancellation system into modular, independently installable components. The microphones, speakers, and controller are designed as separate modules that can be individually mounted on existing helmets without requiring structural modifications to the helmet itself. This modular approach allows the system to be retrofitted to various helmet models while maintaining ease of installation and avoiding complex manufacturing changes.
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 solution provides efficient noise cancellation in a defined frequency range, enhancing user safety and comfort by reducing unwanted noise while preserving important sound information, and can be easily integrated into existing helmets without structural modifications.
Implementation Method 1
The original sound wave and the sound wave from the noise cancellation speaker destructively interfere with one another to effectively cancel each other out
Implementation Method 2
a sound wave with the same amplitude but with opposite phase (also known as 'antiphase', 'antinoise' or 'antisound') to the original sound
Data Source
AI summary
An active noise cancellation (ANC) system has a mounting plate, a first face of which is configured to be disposed against an inner surface of a helmet to form, with the helmet, a chamber. When the mounting plate is mounted on the helmet, a loudspeaker provided on the first face of the mounting plate is within the chamber. The plate has an aperture for allowing transmission of sound from the loudspeaker to the spatial region. At least one reference microphone is mounted on a second face of the plate. The plate acts as a mounting plate for components of the ANC system, simplifying the process of installing an ANC system. Also, the plate serves to define a chamber that accommodates the loudspeaker of the ANC system and provides good acoustic coupling of the sound signal from the loudspeaker of the ANC system into the quiet zone of the ANC system.