Active Noise Control Helmet with Dual-Channel Feedback
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Solution Overview
Problem
Motorcyclists face impaired hearing and safety risks due to high noise levels from engine and wind noise, which existing noise reduction methods, including traditional helmets and active noise cancellation systems, fail to adequately address, especially under harsh acoustical conditions encountered during high-speed riding.
Innovation Solution
A helmet system incorporating an active noise control module with two channels, each having an error-signal input and a reference-signal input, electrically coupled to loudspeakers and microphones positioned to reproduce noise-reducing signals, effectively cancels noise by generating signals from error and reference signals picked up at opposing positions, utilizing a combination of feedback and feed-forward ANC sub-systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional helmets with sound deadening material are used, then noise levels are reduced, but hearing ability is impaired and safety is compromised
Solution Approach 1:
The patent implements feedback-based active noise control where microphones detect noise inside the helmet and the control module generates anti-phase signals through loudspeakers to cancel the noise, dynamically adjusting to maintain both noise reduction and hearing safety
Solution Approach 2:
The patent introduces an active noise control module as an intermediary system between the external noise source and the rider's ear, using electronic signal processing to cancel noise without blocking the ear canal, thus preserving natural hearing
2Object-affected harmful factors
If earplugs are used to reduce noise, then noise levels are reduced, but hearing ability and safety are impaired
Solution Approach 1:
The patent replaces the mechanical passive blocking method of earplugs with an electronic active noise control system that uses microphones, signal processing, and loudspeakers to cancel noise acoustically without physical obstruction of the ear canal
3Object-affected harmful factors
If active noise cancellation systems are built-in, then noise levels are reduced, but device complexity increases
Solution Approach 1:
The patent divides the helmet into functionally independent segments: passive noise isolation layers for structural noise reduction and an active noise control module with separate microphones and loudspeakers for acoustic noise cancellation, allowing each component to be optimized independently
Solution Approach 2:
The active noise control module serves multiple functions: it reduces acoustic noise, maintains hearing safety, and can be integrated into various helmet designs without requiring complete redesign of the helmet structure
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 system significantly reduces noise levels, enhancing motorcyclist safety by improving hearing ability and reducing fatigue, while maintaining comfort and fit through the use of memory foam and vibration-dampening materials, effectively addressing the limitations of existing noise cancellation technologies in helmets.
Implementation Method 1
an active noise control module (112) having two channels (301, 302)... The outputs of the two channels (301, 302) are electrically coupled to the two loudspeakers (108, 109)... acoustically reproducing two electrical noise reducing signals at two opposing positions in a helmet
Implementation Method 2
two microphones (110, 111) disposed in the vicinity of the two loudspeakers (108, 109)... picking up sound at positions in the vicinity of the positions where the noise reducing signals are reproduced
Implementation Method 3
maintaining comfort and fit through the use of memory foam and vibration-dampening materials
Implementation Method 4
maintaining comfort and fit through the use of memory foam and vibration-dampening materials
Data Source
AI summary
Exemplary noise reducing methods and systems are configured to acoustically reproduce two electrical noise reducing signals at two opposing positions in a helmet; to pick up sound at positions in the vicinity of the positions where the noise reducing signals are reproduced; and to generate the two noise reducing signals from error-signals and reference-signals. For each noise reducing signal, the corresponding error-signal is generated from the sound picked-up at the same position where the respective noise reducing signal is reproduced; and the reference-signal is generated from the sound picked-up at the position where the respective other noise reducing signal is reproduced.