Environmental noise variable-excitation amplitude modulation and frequency modulation detecting and estimating method
A technology for environmental noise and frequency modulation detection, which is used in measuring devices, using electromagnetic means, and measuring ultrasonic/sonic/infrasonic waves to achieve the effect of expanding the detection range
Active Publication Date: 2015-06-24
XIAN FEISIDA AUTOMATION ENG
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[0006] In order to overcome the need for different types of noise sensors and magnetic saturation problems and technical defects in different environmental noises, the present invention provides a method for detecting and estimating environmental noise variable excitation amplitude modulation and frequency modulation. The common excitation method uses pulse width modulation (PWM) to control the size and direction of coil electric excitation to form magnetic fields and hysteresis loops of different strengths, thereby changing the frequency and amplitude of the received acoustic signal and expanding the improved dynamics. The detection range of the coil microphone; then restore the frequency of the detected signal, and then calculate the noise intensity, which solves the problem that the existing dynamic noise sensor needs different models and magnetic saturation in different environmental noises
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[0023] refer to figure 1 .
[0024] (1) Improve the permanent magnet core in the moving coil microphone composed of vibrating diaphragm, voice coil, permanent magnet core and step-up transformer into a spinel soft magnetic core, and wind the coil and soft magnet on the soft magnetic core Common excitation of cores; excitation mode with controllable strength of excitation size, direction and hysteresis loop;
[0025] (2) The DSP2407 outputs the PWM waveform to control the magnitude and direction of the DC current of the coil on the soft magnetic core, forming magnetic fields and hysteresis loops of different strengths, thereby changing the frequency and amplitude of the received acoustic signal, and expanding the improved moving coil The detection range of the type microphone;
[0026] (3) By applying different PWMs to the coils on the soft magnetic core, the simulated audio signal of a given frequency is tested, and the following formula is obtained through data fitting:
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The invention provides an environmental noise variable-excitation amplitude modulation and frequency modulation detecting and estimating method in order to overcome the technical defect that different types of noise sensors are needed for different environmental noises and to solve the magnetic saturation problem. The method has the advantages that by a common excitation mode of winding a coil on a soft magnetic core prior to powering on, size and direction of electric excitation of the coil are controlled by means of PWM (pulse width modulation) so as to form magnetic fields and hysteresis loops in different intensities, so that frequency and amplitude of received acoustical signalsare changed, and detection range of a sensor is enlarged; detected signals are subjected to frequency reduction, then noise intensity is computed, and the problem that existing moving-coil noise sensors require different types and magnetic saturation for different environmental noises is solved.
Description
technical field [0001] The invention relates to the technical field of environmental noise measurement, in particular to a detection and estimation method for variable excitation amplitude modulation and frequency modulation of environmental noise. Background technique [0002] With the development of modern urban construction and urban transportation, urban environmental noise pollution has become an important environmental problem faced by major cities in the world; noise pollution has become the fourth largest environmental hazard after water pollution, air pollution, and solid waste pollution; Urban noise pollution has seriously affected people's normal work, study and rest. The number of noise pollution complaints has always ranked first among all kinds of environmental pollution complaints. Timely and accurate detection, analysis and effective control of environmental noise are particularly important. [0003] At present, the sensors for detecting noise can be divided ...
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IPC IPC(8): G01H11/02
Inventor 史忠科王艳丽胥效文
Owner XIAN FEISIDA AUTOMATION ENG