CN111710325B - A fault detection method for error sound transmission and secondary sound source based on active noise reduction - Google Patents

Abstract

The invention discloses a fault detection method of error sound transmission and secondary sound source based on active noise reduction, and relates to the field of detection of active noiseThe technical field of cabin noise control comprises the following steps: calculating a sound pressure level matrix V _mn (ii) a Detecting and judging a secondary sound source; and detecting and judging by an error microphone. The error microphone and secondary sound source fault detection method based on active noise reduction realizes the function of a hardware detection circuit on the premise of not changing the hardware of cabin active noise reduction equipment, conveniently and quickly detects the working states of the error microphone and the secondary sound source of the active noise reduction equipment component, does not need additional hardware circuit support, reduces the cost problem in engineering application, has high efficiency and reliability, and simultaneously meets the accuracy and economic benefit.

Description

A fault detection method for error sound transmission and secondary sound source based on active noise reduction

technical field

The invention relates to the technical field of cabin noise control, in particular to an error sound transmission based on active noise reduction and a fault detection method for a secondary sound source.

Background technique

Cabin noise control technology is divided into passive control and active control. Passive noise control mainly adopts the method of installing sound insulation and sound absorption materials on the bulkhead. The low-frequency noise reduction effect is limited, and to a certain extent, it takes up space, increases the weight of the product, and increases energy consumption. In the 1990s, people began to develop Active Noise Control (ANC) technology for cabins of vehicles, turboprop aircraft, and helicopters, which has the advantages of wide control frequency band, small mass, flexible layout, and strong frequency band pertinence. There are actual engineering application cases.

The existing ANC system arranges error microphones and secondary sound sources in several positions in the cabin, and the control system adopts centralized control. The function goal of the system is to realize the noise reduction area near the position of each error microphone. Yes, the control effects of all control areas are the same, and the damage of any part may lead to system instability and reduce the noise reduction effect, but it is very difficult to find the cause.

Before the error microphone and secondary sound source are installed, troubleshooting is relatively simple, but for the error microphone and secondary sound source after installation, when they fail, the detection becomes difficult, especially the secondary sound source failure Detection is more difficult, and the noise reduction performance of the noise reduction equipment cannot be guaranteed without fault detection and troubleshooting.

Aiming at the problems in the related technologies, no effective solution has been proposed yet.

Contents of the invention

Aiming at the problems in the related technologies, the present invention proposes an error sound transmission based on active noise reduction and a fault detection method for secondary sound sources, and implements a hardware detection circuit without changing the hardware of the active noise reduction equipment in the cockpit. The function is convenient and fast to detect the working status of the active noise reduction equipment component error microphone and secondary sound source, without additional hardware circuit support, reducing the cost problem in engineering applications, and has high efficiency and reliability, while meeting other requirements Accuracy and economic benefits, to overcome the above-mentioned technical problems existing in the related art.

Technical scheme of the present invention is realized like this:

A fault detection method for error sound transmission and secondary sound source based on active noise reduction, comprising the following steps:

Step S2, calculating the sound pressure level matrix V _mn ; where;

V _mn is the average sound pressure level of the data in the n(1,...,N)th error microphone 1s when the m(1,...,M)th secondary sound source is sounding, expressed as:

为1s内采样点的平方和的均方根值，表示为第n(1，...，N)个误差传声器1s内的声压平均值；Among them, p _ref is the reference sound pressure,

is the root mean square value of the sum of squares of the sampling points within 1s, expressed as the average sound pressure of the nth (1,...,N) error microphone within 1s;

Step S3, secondary sound source detection and judgment; wherein;

X _m is the maximum value of V _mn (n={1 ... N}) when the m(1,...,M)th secondary sound source finishes speaking, expressed as:

X _m = max{V _m1 ... V _mN },

Wherein, if X _m is less than the data invalid threshold T _invalid =45(dB), then X _m =0;

Find the maximum value X _max from X _m , X _max is the maximum value of X ₁ , X ₂ ... X _M , expressed as: X _max = max{X ₁ ... X _M },

If the absolute value of the difference between X _m and X _max is greater than the threshold T _src = 20dB or X _max is equal to 0, it is determined that the mth secondary sound source is faulty, otherwise the secondary sound source is normal, expressed as:

The mth secondary sound source failure = {|X _m -X _max |>T _src or X _max ==0},

Step S4, error microphone detection and judgment; wherein;

Y _n is the maximum value of V _mn (m={1 ... M}) when all m secondary sound sources have finished speaking, expressed as:

Y _n = max{V _1n ... V _Mn },

Wherein, if Y _n is less than the data invalid threshold T _invalid =45(dB), then Y _n =0;

Find the maximum value Y _max from Y _n , Y _max is the maximum value of Y ₁ , Y ₂ ... Y _n , expressed as:

Y _max = max {Y ₁ , Y ₂ . . . Y _n },

If the absolute value of the difference between Y _n and Y _max is greater than the threshold T _error = 25dB or Y _max is equal to 0, it is determined that the nth error microphone is faulty, otherwise the error microphone is normal, expressed as:

nth error microphone failure = {|Y _n −Y _max |>T _error or Y _max ==0}.

Further, the following steps are included:

Step S1, the secondary sound source makes a sound once, wherein;

The active noise reduction equipment uses DA (Digital to Analog, digital-to-analog conversion) to make each secondary sound source sequentially emit a 200Hz sinusoidal signal with an amplitude of 10V, and the sounding time interval of each secondary sound source is 1s.

Further, the following steps are also included:

Step S101, all error sensors receive signals.

Further, its step error microphone detection and judgment includes detecting whether all secondary sound sources have sounded, including the following steps:

Step S401, if all secondary sound sources have sounded, calculate the maximum value Y _n ;

Step S402, if all the secondary sound sources have not sounded, the secondary sound source makes sound once, and the steps are repeated.

Beneficial effects of the present invention:

The present invention is based on the error sound transmission of the active noise reduction and the fault detection method of the secondary sound source, and realizes the function of the hardware detection circuit without changing the hardware of the active noise reduction equipment in the cockpit, so that the active noise reduction can be detected conveniently and quickly. Noise equipment component error microphone and the working state of the secondary sound source, without additional hardware circuit support, reduce the cost problem in engineering applications, and have high efficiency and reliability, while meeting its accuracy and economic benefits.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic flow chart of an error sound transmission based on active noise reduction and a fault detection method of a secondary sound source according to an embodiment of the present invention;

Fig. 2 is a data schematic diagram of an error sound transmission based on active noise reduction and a secondary sound source fault detection method according to an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention belong to the protection scope of the present invention.

According to an embodiment of the present invention, an error sound transmission based on active noise reduction and a fault detection method of a secondary sound source are provided.

As shown in FIG. 1 , the error sound transmission based on active noise reduction and the fault detection method of the secondary sound source according to the embodiment of the present invention include the following steps:

Step S2, calculating the sound pressure level matrix V _mn ; where;

V _mn is the average sound pressure level of the data in the n(1,...,N)th error microphone 1s when the m(1,...,M)th secondary sound source is sounding, expressed as:

为1s内采样点的平方和的均方根值，表示为第n(1，…，N)个误差传声器1s内的声压平均值；Among them, p _ref is the reference sound pressure, which is the standard atmospheric pressure,

is the root mean square value of the sum of squares of the sampling points within 1s, expressed as the average sound pressure of the nth (1,...,N) error microphone within 1s;

Step S3, secondary sound source detection and judgment; wherein;

X _m is the maximum value of V _mn (n={1 ... N}) when the m(1,...,M)th secondary sound source finishes speaking, expressed as:

X _m = max{V _m1 ... V _mN },

Wherein, if X _m is less than the data invalid threshold T _invalid =45 (dB), then X _m =0;

Find the maximum value X _max from X _m , X _max is the maximum value of X ₁ , X ₂ ... X _M , expressed as: X _max = max{X ₁ ... X _M },

If the absolute value of the difference between X _m and X _max is greater than the threshold T _src = 20dB or X _max is equal to 0, it is determined that the mth secondary sound source is faulty, otherwise the secondary sound source is normal, expressed as:

The mth secondary sound source failure = {|X _m -X _max |>T _src or X _max ==0},

Step S4, error microphone detection and judgment; wherein;

Y _n is the maximum value of V _mn (m={1 ... M}) when all m secondary sound sources have finished speaking, expressed as:

Y _n = max{V _1n ... V _Mn },

Wherein, if Y _n is less than the data invalid threshold T _invalid =45(dB), then Y _n =0;

For example, when n=1, Y ₁ =max{V ₁₁ ... V _m1 }, if Y ₁ <T _invalid , then Y ₁ =0;

For example, when m=1, X ₁ =max{V ₁₁ ... V _1N }, if X ₁ <T _invalid , then X ₁ =0;

Find the maximum value Y _max from Y _n , Y _max is the maximum value of Y ₁ , Y ₂ ... Y _n , expressed as:

Y _max = max {Y ₁ , Y ₂ . . . Y _n },

If the absolute value of the difference between Y _n and Y _max is greater than the threshold T _error = 25dB or Y _max is equal to 0, it is determined that the nth error microphone is faulty, otherwise the error microphone is normal, expressed as:

nth error microphone failure = {|Y _n −Y _max |>T _error or Y _max ==0}.

With the help of the above technical solution, based on the error sound transmission of active noise reduction and the fault detection method of the secondary sound source, the function of the hardware detection circuit is realized without changing the hardware of the active noise reduction equipment in the cockpit, which is convenient and fast Detect the working status of the active noise reduction equipment component error microphone and secondary sound source without additional hardware circuit support, reduce the cost problem in engineering applications, and have high efficiency and reliability, while meeting its accuracy and economic benefits.

Among them, the following steps are included:

Step S1, the secondary sound source makes a sound once, wherein;

The active noise reduction equipment uses DA (Digital to Analog, digital-to-analog conversion) to make each secondary sound source sequentially emit a 200Hz sinusoidal signal with an amplitude of 10V, and the sounding time interval of each secondary sound source is 1s.

Among them, the following steps are also included:

Step S101, all error sensors receive signals.

Wherein, its step error microphone detection and judgment includes detecting whether all secondary sound sources have sounded, including the following steps:

Step S401, if all secondary sound sources have sounded, calculate the maximum value Y _n ;

Step S402, if all the secondary sound sources have not sounded, the secondary sound source makes sound once, and the steps are repeated.

It can be obtained that Y _max =X _max , and the fault judgment thresholds T _src and T _error can be fine-tuned according to the background noise value of the actual use scene.

In addition, in one embodiment, specifically, an active noise reduction device with 8 secondary sound sources and 14 error microphones is installed in a cabin, set:

Effective threshold of secondary sound source T _src = 20dB;

Error microphone effective threshold T _error = 25dB;

The signal valid threshold T _invalid =45 (dB).

As shown in FIG. 2 , the column direction of the table represents the sound pressure level V _mn received by the 14 error microphones when a certain secondary sound source occurs. The horizontal direction is expressed as the sound pressure level V _mn of 8 secondary sound sources received by a certain error microphone in turn. Max is the maximum value X _m and Y _n of the corresponding row or column.

It can be seen from FIG. 2 that the minimum value of all error microphone signal data is 50 dB, which is greater than the valid signal threshold T _invalid =45 (dB).

The maximum sound pressure level of the 8 secondary sound sources received by the error microphone numbered 5 is 60dB, while the maximum sound pressure level of the 14 error microphones is 89dB, the difference is 29dB, which is greater than the effective threshold T _error = 25dB, so the number 5 can be judged error microphone failure.

The maximum signal received by the 14 error microphones is 67dB when the secondary sound source numbered 7 is sounding, and the maximum signal received by the 14 error microphones is 89dB, with a difference of 22dB, which is greater than the effective threshold T _src = 20dB, so the number 7 can be judged failure of the secondary sound source.

In the same way, it can be seen that other error microphones and secondary sound sources are normal and have no faults.

With the help of the above scheme, the error sound transmission based on active noise reduction and the fault detection method of the secondary sound source have good adaptability, and only need to change the three detection thresholds T _src , T _invalid and T _error for different cabin environments. By changing the algorithm without changing the hardware circuit, the working state detection of the secondary sound source and the error microphone can be prepared. It avoids adding a hardware detection circuit in the error microphone and the secondary sound source circuit, and does not need additional detection value calibration and initialization modeling comparison.

To sum up, with the help of the above technical solution of the present invention, based on the error sound transmission of active noise reduction and the fault detection method of the secondary sound source, the hardware can be realized without changing the hardware of the active noise reduction equipment in the cockpit. The function of the detection circuit is convenient and fast to detect the working status of the active noise reduction equipment component error microphone and secondary sound source, without additional hardware circuit support, reducing the cost problem in engineering applications, and has high efficiency and reliability. Meet its accuracy and economic benefits.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (4)

1. A fault detection method of error sound transmission and secondary sound source based on active noise reduction is characterized by comprising the following steps:

calculating a sound pressure level matrix V _mn (ii) a Wherein;

V _mn for the M (1,. Said., M) th secondary sound source, the average sound pressure level of the data in the N (1, …, N) th error microphone 1s is expressed as:

wherein p is _ref For the purpose of reference to the sound pressure,

the root mean square value of the sum of squares of the sampling points in 1s is expressed as the average value of sound pressure in the N (1, …, N) th error microphone 1 s;

detecting and judging a secondary sound source; wherein;

X _m when the M (1.. Gtorem) secondary sound source finishes sounding, V _mn The maximum value of (N = {1 … N }) is expressed as:

X _m ＝max{V _m1 …V _mN }，

wherein, if X _m Less than a data invalidation threshold T _invalid =45 (dB), then X _m ＝0；

From X _m Find out the maximum value X _max ，X _max Is X ₁ ，X ₂ …X _M Expressed as:

X _max ＝max{X ₁ …X _M }，

if X _m And X _max Of (2) is poorAbsolute value greater than threshold T _src =20dB or X _max If the secondary sound source is equal to 0, the m-th secondary sound source is judged to be in fault, otherwise, the secondary sound source is normal, and the conditions are represented as follows:

m-th secondary sound source fault = { | X _m -X _max |＞T _src Or X _max ＝＝0}，

Detecting and judging an error microphone; wherein;

Y _n when all m secondary sound sources finish sounding, V _mn (M = {1 … M }) the maximum value expressed as:

Y _n ＝max{V _1n ……V _Mn }，

wherein, if Y _n Less than a data invalidation threshold T _invalid =45 (dB), then Y _n ＝0；

From Y _n Find out the maximum value Y _max ，Y _max Is Y ₁ ，Y ₂ ……Y _n Expressed as:

Y _max ＝max{Y ₁ ，Y ₂ ……Y _n }，

if Y is _n And Y _max Is greater than a threshold value T _error =25dB or Y _max If the error microphone is equal to 0, the nth error microphone is judged to be in fault, otherwise, the error microphone is normal, and the steps are represented as follows:

fault of nth error microphone = { | Y _n -Y _max |＞T _error Or Y _max ＝＝0}。

2. The method for fault detection of error propagation and secondary sound source based on active noise reduction according to claim 1, characterized by further comprising the steps of:

the secondary sound source produces sound once, wherein;

the active noise reduction equipment enables each secondary sound source to sequentially emit sinusoidal signals with 200Hz amplitude of 10V through DA, and the sounding time interval of each secondary sound source is 1s.

3. The method for detecting faults of error transmitting and secondary sound sources based on active noise reduction according to claim 2, characterized by further comprising the steps of:

all error sensors receive signals.

4. The method for detecting errors in acoustical transmission and secondary sound sources based on active noise reduction according to claim 3, wherein the step of error microphone detection and determination includes detecting whether all secondary sound sources have sounded, comprising the steps of:

if all secondary sound sources have sounded, calculating the maximum value Y _n ；

If all the secondary sound sources do not produce sound, the secondary sound sources produce sound once, and the steps are repeated.

Images