阅读说明：本技术 一种用于有源噪声控制系统具有故障检测功能的次级声源及故障检测方法 (Secondary sound source with fault detection function for active noise control system and fault detection method ) 是由 代海 王洋 玉昊昕 王金林 宁晓峰 行晓亮 袁梦囝 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种用于有源噪声控制系统具有故障检测功能的次级声源及故障检测方法,次级声源包括喇叭单体、电压采集模块、声采集模块以及微处理器,所述电压采集模块连接喇叭单体,所述微处理器分别连接电压采集模块、声采集模块以及有源噪声控制系统的有源噪声控制器。本发明使用了可靠性高的硅麦传声器,具有成本低、性能成本低、性能稳定的优点,误报率与漏报率非常低；故障检测的声采集模块置于次级声源箱体的内部,不受外界噪声的干扰,能够检测到次级声源较低声压的输出,同时保证了准确度；在有源噪声控制系统正常工作的同时,可实时了解到次级声源的状态,对于系统而言,次级声源部件具有独立的故障检测和故障上报功能。(The invention discloses a secondary sound source with a fault detection function for an active noise control system and a fault detection method. The invention uses the silicon microphone with high reliability, has the advantages of low cost, low performance cost and stable performance, and has very low false alarm rate and missing report rate; the sound acquisition module for fault detection is arranged in the secondary sound source box body, is not interfered by external noise, can detect the output of lower sound pressure of the secondary sound source, and simultaneously ensures the accuracy; when the active noise control system works normally, the state of the secondary sound source can be known in real time, and for the system, the secondary sound source part has independent fault detection and fault reporting functions.)

1. A secondary sound source with fault detection for an active noise control system, characterized by: the loudspeaker comprises a loudspeaker single body, a voltage acquisition module, a sound acquisition module and a microprocessor, wherein the voltage acquisition module is connected with the loudspeaker single body, and the microprocessor is respectively connected with the voltage acquisition module, the sound acquisition module and an active noise controller of an active noise control system; the voltage acquisition module is connected with the active noise controller.

2. A secondary sound source with fault detection for an active noise control system according to claim 1, characterized by: the sound acquisition module is a silicon microphone.

3. A fault detection method for an active noise control system, the method comprising:

setting detection threshold T for secondary sound source finished product₀And T₁(ii) a The active noise control system can give secondary signals to a secondary sound source in a working state to enable a horn monomer in the secondary sound source to sound, a voltage acquisition module acquires voltage U in the working state, a silicon microphone acquires acoustic signals V in a current state and provides the acoustic signals V to a microprocessor to enable the microprocessor to perform data calculation and analysis, the data calculation comprises the steps of performing FFT (fast Fourier transform algorithm) processing on the signals, calculating amplitude A and phase P of frequency points and calculating absolute value | T of the difference value between the amplitude and the phase in the current state_AI and T_PAnd comparing the state of the secondary sound source with a set threshold value, judging the state of the secondary sound source according to a comparison result, and finally feeding back a fault detection result to the active noise controller by the microprocessor.

4. A fault detection method for an active noise control system according to claim 3, characterized in that: the method comprises the following steps:

s1, collecting a voltage signal U and an acoustic signal V;

s2, carrying out FFT processing on the voltage signal and the acoustic signal;

s3, calculating a for a certain frequency point n_n+b_nAmplitude a and phase P denoted by i:

P＝atan2(b_n,a_n) (2)

wherein atan2(Y, X) is an angle representing the corresponding (X, Y) coordinate in the X-Y plane, and its range of value is (- π, π);

s4, calculating the absolute value of the difference value between the amplitude and the phase value of the voltage signal and the acoustic signal at a certain frequency point in the current state, and recording the absolute value as | T_AI and T_P|；

S5, judging whether the secondary sound source fails or not

And (4) when the formulas (3) and (4) are simultaneously established, judging that the secondary sound source is in failure, otherwise, judging that the secondary sound source is not in failure.

|T_A|≤T₀ (3)

|T_p|≤T₁ (4)。

Technical Field

The invention relates to the technical field of active noise control systems, in particular to a secondary sound source with a fault detection function and a fault detection method for an active noise control system.

Background

In an active noise control system, a secondary sound source is used as one of important electroacoustic devices, and plays secondary noise data to generate acoustic interference with primary noise, so that the noise reduction effect can be achieved. In the operation process of the noise reduction system, the secondary sound source can be out of order for various reasons, if the secondary sound source can not be found in time, the played secondary noise data can be changed unexpectedly, even the secondary sound source plays a role in 'reaction', the noise of a primary sound field is increased, and the system is unstable. However, in the use process of the secondary sound source, the use environment is noisy, and it is impossible to manually distinguish which secondary sound source is failed. The quality of the secondary sound source directly affects the noise reduction performance of the active noise reduction device.

For the fault detection of the secondary sound source, currently, the fault detection is performed when the used device is initialized, which can only determine whether the secondary sound source is faulty before being used, and this fault detection method cannot detect the fault of the secondary sound source in real time when the device is used. The secondary sound source fault detection of part of systems by adopting the impedance method requires that a secondary sound field must be white noise or a frequency sweep signal, however, when the actual noise reduction system works, the low-frequency and narrow-band noise is mostly aimed at, so the fault detection by adopting the impedance method has certain limitation.

The invention uses a classical microphone detection method, judges whether a secondary sound source is effective or not according to an active noise control logic, and takes a signal received by a microphone as a judgment basis. The microphone uses a silicon microphone with very high reliability, and has the advantages of low cost and stable performance.

Disclosure of Invention

A secondary sound source with a fault detection function for an active noise control system and a fault detection method mainly aim to detect whether the secondary sound source has a fault or not in real time under the condition that active noise reduction equipment normally works.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a secondary sound source that is used for active noise control system to have fault detection function, includes loudspeaker monomer, voltage acquisition module, sound collection module and microprocessor, the loudspeaker monomer is connected to the voltage acquisition module, microprocessor connects voltage acquisition module, sound collection module and active noise control system's active noise controller respectively. The voltage acquisition module is connected with the active noise controller.

The sound acquisition module is a silicon microphone.

A fault detection method for an active noise control system is as follows:

setting detection threshold T for secondary sound source finished product₀And T₁(ii) a The active noise control system can give secondary signals to a secondary sound source in a working state to enable a horn monomer in the secondary sound source to sound, a voltage acquisition module acquires voltage U in the working state, a silicon microphone acquires acoustic signals V in a current state and provides the acoustic signals V to a microprocessor to enable the microprocessor to perform data calculation and analysis, the data calculation comprises the steps of performing FFT (fast Fourier transform algorithm) processing on the signals, calculating amplitude A and phase P of frequency points and calculating absolute value | T of the difference value between the amplitude and the phase in the current state_AI and T_PAnd comparing the state of the secondary sound source with a set threshold value, judging the state of the secondary sound source according to a comparison result, and finally feeding back a fault detection result to the active noise controller by the microprocessor.

A fault detection method for an active noise control system specifically comprises the following steps:

s1, collecting a voltage signal U and an acoustic signal V;

s2, carrying out FFT processing on the voltage signal and the acoustic signal;

s3, calculating a for a certain frequency point n_n+b_nAmplitude a and phase P denoted by i:

P＝atan2(b_n,a_n) (2)

wherein atan2(Y, X) is an angle representing the corresponding (X, Y) coordinate in the X-Y plane, and its range of value is (- π, π);

s4, calculating the absolute value of the difference value between the amplitude and the phase value of the voltage signal and the acoustic signal at a certain frequency point in the current state, and recording the absolute value as | T_AI and T_P|；

S5, judging whether the secondary sound source fails or not

And (4) when the formulas (3) and (4) are simultaneously established, judging that the secondary sound source is in failure, otherwise, judging that the secondary sound source is not in failure.

|T_A|≤T₀ (3)

|T_p|≤T₁ (4)。

The invention has the technical effects and advantages that:

1. the sound acquisition module for fault detection is arranged in the secondary sound source box body, is not interfered by external noise, can detect the output of lower sound pressure of the secondary sound source, and simultaneously ensures the accuracy;

2. the silicon microphone with high reliability is used, so that the silicon microphone has the advantages of low cost, low performance cost and stable performance, and the false alarm rate and the missing report rate are very low;

3. when the active noise control system works normally, the state of the secondary sound source can be known in real time, and for the system, the secondary sound source part has independent fault detection and fault reporting functions.

Drawings

FIG. 1 is a schematic diagram of a fault detection function module of the present invention;

FIG. 2 is a view showing a constitution of a secondary sound source;

FIG. 3 is a flow chart of a secondary source fault detection method;

fig. 4 is a plot of FFT modulo.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

A secondary sound source with a fault detection function for an active noise control system and a fault detection method mainly aim to detect whether the secondary sound source has a fault or not in real time under the condition that active noise reduction equipment normally works.

The principle module of the secondary sound source with fault detection function for the active noise control system mainly comprises an active noise controller and a secondary sound source, as shown in fig. 1. The secondary sound source comprises a Speaker monomer Speaker, a voltage acquisition module (AD acquisition), a silicon microphone MIC and a microprocessor MCU, as shown in fig. 2.

Example two

A fault detection method for an active noise control system, comprising the steps of:

firstly, setting a detection threshold value T for a secondary sound source finished product₀And T₁. The active noise control system can give secondary signals to a secondary sound source in a working state to enable a horn monomer in the secondary sound source to sound, a voltage acquisition module can acquire voltage U in the working state, a silicon microphone can acquire acoustic signals V in the current state and then provide the acoustic signals V to a micro-processing module to enable the micro-processing module to perform data calculation and analysis, wherein the data calculation comprises the steps of performing FFT (fast Fourier transform) processing on the signals, calculating amplitude A and phase P of frequency points and calculating absolute value | T of the difference value between the amplitude and the phase in the current state_AI and T_PAnd comparing the state of the secondary sound source with a set threshold value, judging the state of the secondary sound source according to a comparison result, and finally feeding back a fault detection result to the active noise controller by the micro-processing module.

The flow of the fault detection method of the secondary sound source is shown in fig. 3:

1. collecting a voltage signal U and an acoustic signal V;

2. performing FFT processing on the voltage signal and the acoustic signal;

3. calculating a certain frequency point n using a_n+b_nAmplitude a and phase P denoted by i:

P＝atan2(b_n,a_n) (2)

wherein atan2(Y, X) is an angle representing the corresponding (X, Y) coordinate in the X-Y plane, and its range of value is (- π, π);

4. calculating the absolute value of the difference value between the amplitude and the phase value of the voltage signal and the acoustic signal at a certain frequency point in the current state, and recording as | T_AI and T_P|；

5. Secondary sound source failure determination

And (4) when the formulas (3) and (4) are simultaneously established, judging that the secondary sound source is in failure, otherwise, judging that the secondary sound source is not in failure.

|T_A|≤T₀ (3)

|T_p|≤T₁ (4)。

EXAMPLE III

For example, the following steps are carried out:

threshold value T set by assuming secondary sound source of qualified finished product of certain model₀Is 3dB, T₁Is composed ofIn the operation of the active noise control system, a secondary signal is output to the secondary sound source, the secondary signal being a narrowband signal.

1. The voltage acquisition module acquires u in a working state and acquires an acoustic signal v by the silicon microphone;

2. performing FFT processing on the voltage signal and the acoustic signal;

3. taking the frequency point n as 107Hz and the electric signal complex number as U_107Hz761.56+1547.64i, the complex number of the acoustic signal is V_107HzThe amplitude a and the phase P are calculated by formulas (1) and (2) as 241.21+2054.47 i:

A₁＝20*log₁₀(sqrt(761.56²+1547.64²))＝64.74dB；

P₁＝atan2(1547.64,761.56)*180°/π＝63.80°；

A₀＝20*log₁₀(sqrt(241.21²+2054.47²))＝66.31dB；

P₀＝atan2(2054.47,241.21)*180°/π＝83.30°。

4. calculating the absolute value of the difference value of the amplitude and the phase value of the voltage signal and the acoustic signal under the current state:

as shown in FIG. 4, the amplitude value A of the acoustic signal at the frequency point can be found₀66.31 dB; amplitude value of the electrical signal is A₁64.74dB, T_A＝|A₀-A₁|＝|66.31-64.74|dB＝1.57dB。

5. And (3) judging whether the secondary sound source fails:

calculating to obtain T_A＝1.57dB＜T₀And if the secondary sound source is 3dB, judging that the secondary sound source is normal, and feeding back a fault detection result of the secondary sound source under the current condition to the active noise controller through the micro-processing module.

Example four

The invention is not only suitable for an active noise control system, but also can be used in a loudspeaker (horn) box body with high reliability requirement. The invention can detect the single performance of the loudspeaker in real time, and can also be used for active sound boxes, such as the loudspeaker of an automobile, the loudspeaker of a high-speed rail car and the like.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.