Broadband Noise Sensor for Vehicle Engine Acoustic Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine noise control systems, such as EOC technology, are limited in reducing non-acoustic noise components like bearing play, chain slack, and valve bounce, as they rely on narrowband feed-forward ANC and non-acoustic sensors like RPM sensors, which cannot effectively counteract these noise sources.
Innovation Solution
A broadband noise and vibration sensor is used to directly pick up engine noise and generate a sense signal, which is then processed through an active noise control filter to produce anti-noise that is radiated to the vehicle interior, reducing engine noise through a filtered-x least mean square algorithm, and is mounted on the engine exhaust mount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If narrowband feed-forward ANC and non-acoustic sensors (RPM sensors) are used, then the system complexity is reduced and manufacturing is easier, but the ability to reduce broadband noise components (bearing play, chain slack, valve bounce) is insufficient
Solution Approach 1:
The patent changes the sensor type from narrowband RPM sensor to broadband noise and vibration sensor, and changes the filtering approach from narrowband filtering to broadband filtering. This parameter change enables the system to capture and process the entire noise spectrum including broadband components, thereby resolving the contradiction between ease of manufacture and broadband noise reduction capability
Solution Approach 2:
The patent employs a universal broadband noise and vibration sensor that can detect both narrowband engine harmonics and broadband noise components (bearing play, chain slack, valve bounce) simultaneously. This multi-functional sensor replaces the need for separate sensors and processing systems, achieving comprehensive noise reduction while maintaining manufacturing simplicity
2Object-affected harmful factors
If broadband noise and vibration sensor with direct engine noise pickup is used, then the broadband noise reduction capability is improved, but the device complexity increases
Solution Approach 1:
The patent uses the engine exhaust mount as an intermediary mounting structure for the broadband noise and vibration sensor. This intermediary approach allows the sensor to be positioned close to the engine for optimal noise pickup while utilizing existing vehicle structures, thereby reducing the overall system complexity despite the advanced sensor requirements
Solution Approach 2:
The patent replaces complex multi-sensor mechanical arrangements with a single broadband sensor that electronically captures the entire noise spectrum. This substitution of mechanical complexity with electronic capability reduces device complexity while maintaining or improving broadband noise reduction performance
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
This approach allows for the reduction of the entire engine noise spectrum, including broadband noise, beyond what narrowband systems can achieve, effectively addressing the limitations of existing technologies by directly capturing and canceling a broader range of noise components.
Implementation Method 1
a broadband noise and vibration sensor configured to directly pick up engine noise from an engine of a vehicle and to generate a sense signal representative of the engine noise
Implementation Method 2
a loudspeaker configured to convert the filtered sense signal from the active noise control filter into anti-noise and to radiate the anti-noise to a listening position
Implementation Method 3
synthesize a sound wave that is opposite in phase to the engine noise audible in the car interior... the anti-noise has the same amplitude but opposite phase as the signals generated by the engine
Data Source
Figure 1
Figure 2~5
Figure 6~7
AI summary
An exemplary engine noise control includes directly picking up engine noise from an engine of a vehicle at a pick-up position to generate a sense signal representative of the engine noise, and active noise control filtering to generate a filtered sense signal from the sense signal. The control further includes converting the filtered sense signal from the active noise control filtering into anti-noise and radiating the anti-noise to a listening position in an interior of the vehicle. The filtered sense signal is configured so that the anti-noise reduces the engine noise at the listening position.