Sensor Module for Active Noise Control Using Vibration and Sound Pressure
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Solution Overview
Problem
Conventional particle velocity sensors are expensive and difficult to install at multiple points with a constant distance from vibrating objects, making active noise control costly and inefficient.
Innovation Solution
A sensor module comprising a first sensor unit for measuring sound pressure and a second sensor unit for measuring vibration, with a signal processing unit that outputs signals for both sound pressure and vibration components, allowing for the estimation of particle velocity from vibration data, reducing the need for multiple expensive sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If particle velocity sensors are used to measure vibration and sound pressure, then measurement precision is improved, but device cost increases significantly
Solution Approach 1:
The patent combines a sound pressure sensor and a vibration sensor into an integrated sensor module that measures both parameters simultaneously. This merging allows the system to obtain both sound pressure and particle velocity information (through vibration measurement) using a single unified device rather than requiring separate expensive particle velocity sensors, thereby reducing overall system cost while maintaining measurement precision.
Solution Approach 2:
The patent replaces the need for complex particle velocity sensors with a combination of simpler sensors: a sound pressure sensor and a vibration sensor. By measuring vibration of the diaphragm or housing, the system can derive particle velocity information mechanically rather than requiring specialized particle velocity sensing elements, thus substituting a complex mechanical system with simpler, more cost-effective components.
2Measurement precision
If multiple particle velocity sensors are installed at constant distances from the object surface, then measurement accuracy is improved, but installation difficulty increases
Solution Approach 1:
By merging sound pressure and vibration sensing capabilities into a single sensor module, the patent eliminates the need for multiple separate sensors installed at precise constant distances. The integrated module can be installed at a single location while still providing both sound pressure and vibration data, significantly simplifying installation while maintaining the ability to perform accurate noise measurements through signal processing.
Solution Approach 2:
The sensor module is designed with multi-functionality, serving both as a sound pressure sensor and a vibration sensor simultaneously. This universal design allows a single device to perform multiple measurement functions that previously required multiple specialized sensors, thereby reducing installation complexity while preserving measurement accuracy through the combined data from both sensing functions.
3Reliability
If vibration insulation is performed for particle velocity sensors, then measurement reliability is improved, but installation flexibility decreases
Solution Approach 1:
The patent merges sound pressure and vibration sensing into a single integrated module where the vibration sensor is inherently coupled to the sensor housing or diaphragm. This integration means that vibration measurement is performed on the sensor structure itself rather than requiring separate vibration insulation measures, thereby maintaining measurement reliability while eliminating the need for additional vibration insulation installations that would reduce flexibility.
Solution Approach 2:
The sensor module performs self-service by using its own housing or diaphragm as the vibration sensing element. The vibration of the sensor structure itself provides the particle velocity information, eliminating the need for external vibration insulation or separate vibration sensing mechanisms. This self-service approach maintains measurement reliability while maximizing installation flexibility across different applications.
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
Enables effective active noise control at a lower cost by using MEMS sensors to measure sound pressure and vibration, allowing for accurate noise reduction without the need for multiple particle velocity sensors.
Implementation Method 1
a first sensor unit that is installed on an object and measures a sound pressure
Implementation Method 2
a second sensor unit that is installed on the object and measures vibration
Implementation Method 3
a signal processing unit that outputs, as module signals, two signals of a signal of a vibration component of the object and a signal of a sound pressure component obtained by removing the vibration component of the object from an output signal of the first sensor unit
Data Source
AI summary
For example, active control can be easily performed at low cost. A sensor module includes: a first sensor unit that is installed on an object and measures a sound pressure; a second sensor unit that is installed on the object and measures vibration; and a signal processing unit that outputs, as module signals, two signals of a signal of a vibration component of the object and a signal of a sound pressure component obtained by removing the vibration component of the object from an output signal of the first sensor unit by using the output signal of the first sensor unit and an output signal of the second sensor unit.