CN107516528B - Audio link self-checking method - Google Patents
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- G—PHYSICS
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- G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
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- G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
- G10L19/02—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis using spectral analysis, e.g. transform vocoders or subband vocoders
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- G—PHYSICS
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- G10L25/00—Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
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Abstract
The invention provides an audio link self-checking method, which comprises the following steps: s1, the main control unit sends the self-checking audio to the coding and decoding unit to obtain the file header parameters of the self-checking audio; s2, decoding the self-checking audio by the encoding and decoding unit to obtain a first self-checking audio analog signal, amplifying by the power amplification unit to obtain a second self-checking audio analog signal, and broadcasting by a loudspeaker; s3, feeding the second self-checking audio analog signal back to the coding and decoding unit for coding, generating a self-checking coding signal and sending the self-checking coding signal to the main control unit; s4, the main control unit generates a self-checking comparison audio according to the self-checking coded signal and a preset format; s5, carrying out spectrum analysis on the self-checking comparison audio through Fourier transform; and S6, comparing the frequency spectrum of the self-checking comparison audio with the frequency spectrum of the self-checking audio, judging whether the audio is normal or not, and prompting the comparison result. The invention realizes the automatic detection of the audio link of the instrument.
Description
Technical Field
The invention relates to the technical field of automobile instruments, in particular to an audio link self-checking method.
Background
The instrument is used as an important component of automobile information display/prompt, and the requirement on safety performance is relatively high. In recent years, with the rapid development of the vehicle-mounted electronic industry and the gradual popularization of digital instruments, some new functions related to safety are gradually popularized, and the addition of the new functions is accompanied by the addition of warning/prompting sounds. Therefore, the voice prompt with high reliability and performance is very important.
The conventional vehicle-mounted audio link is an open-loop circuit, and has no self-checking function for detecting whether the system works normally or not, that is, when a driver cannot hear a warning/warning sound, the driver cannot determine whether the system is in a normal condition or the system is caused by the damaged audio link, which is a very serious problem for safe driving.
Therefore, the prior art is in need of further improvement.
Disclosure of Invention
The invention provides an audio link self-checking method, which aims to overcome the defects in the prior art and realize the automatic detection of an instrument audio link.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the invention provides an audio link self-checking method, which comprises the following steps:
s1, the main control unit sends the self-checking audio to the coding and decoding unit to obtain the file header parameters of the self-checking audio;
s2, decoding the self-checking audio by the encoding and decoding unit to obtain a first self-checking audio analog signal, amplifying by the power amplification unit to obtain a second self-checking audio analog signal, and broadcasting by a loudspeaker;
s3, feeding the second self-checking audio analog signal back to the coding and decoding unit for coding, generating a self-checking coding signal and sending the self-checking coding signal to the main control unit;
s4, the main control unit generates a self-checking comparison audio according to the self-checking coded signal and a preset format;
s5, carrying out spectrum analysis on the self-checking comparison audio through Fourier transform;
and S6, comparing the frequency spectrum of the self-checking comparison audio with the frequency spectrum of the self-checking audio, judging whether the audio is normal or not, and prompting the comparison result.
Specifically, the S5 includes:
s501, determining the number of first sampling points according to the frequency of the self-checking audio and the system sampling rate;
s502, determining the number of second sampling points according to the number of the first sampling points and the frequency reduction multiple of the system sampling rate;
s503, determining a sampling period according to the number of the stored sampling points and the number of the second sampling points;
s504, determining each input value of Fourier transform according to each sampling value and sampling digit;
s505, carrying out Fourier transform on each input value subjected to Fourier transform to obtain a real part and an imaginary part of each input value;
s506, performing modulus calculation on the real part and the imaginary part of each input value to obtain a magnitude array;
s507, obtaining a subscript corresponding to the maximum amplitude in the amplitude array;
and S508, calculating corresponding frequency according to the subscript.
Specifically, the first sampling point number C1 is fs/f, where fs is the system sampling rate and f is the frequency of the self-test audio.
Specifically, the second number of sampling points C2 is C1/R, where C1 represents the first number of sampling points, and R represents the down-conversion multiple of the system sampling rate.
Specifically, the sampling period Ts is k/C2, where k is the number of sample points to be stored, and C2 is the second number of sample points.
In particular, each input value Wi ═ Vi/2 of the Fourier transformBs(i ═ 1,2,3 … k), where Vi denotes each sample value and Bs is the number of sample bits.
In particular, the frequency fBST＝[(fs/R)*(num+1)]and/N, wherein fs is the system sampling rate, R is the preset system sampling rate frequency reduction multiple, num is the subscript value corresponding to the maximum amplitude value, and N is the frequency-reduction system sampling rate average frequency.
Specifically, the header parameters include a system sampling rate and a sampling bit number.
In particular, the frequency of the self-test audio is below 20 Hz.
Specifically, the main control unit communicates with the encoding and decoding unit through I2S.
The invention has the beneficial effects that: according to the invention, the analog audio signal amplified by the power amplification unit is fed back to the coding and decoding unit to generate the self-checking comparison audio, the self-checking comparison audio is subjected to spectrum analysis through Fourier transform, and the frequency spectrum of the self-checking comparison audio is compared with the frequency spectrum of the self-checking audio, so that whether the audio link is normal or not is determined, and the automatic detection of the instrument audio link is realized.
Drawings
FIG. 1 is a schematic diagram of an apparatus for an audio link self-test method according to the present invention;
fig. 2 is a flow chart of the audio link self-checking method of the present invention.
Detailed Description
The embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are for reference and illustrative purposes only and are not intended to limit the scope of the invention.
Fig. 1 is a diagram of an apparatus of the present invention, which includes a main control unit, an encoding and decoding unit, a power amplifier unit, a speaker, and a result prompting unit, wherein:
the main control unit: the device is used for reading the self-checking audio and converting the self-checking audio into an audio digital signal, or generating a comparison audio file from the feedback digital signal, and performing Fourier transform and result comparison.
The encoding and decoding unit: for converting an audio digital signal into an audio analog signal or vice versa.
The power amplifier unit: for power amplifying the audio analog signal.
The loudspeaker: for converting the amplified audio analog signal into an acoustic signal.
The result prompting unit: and the comparison result is prompted.
Based on the device diagram, as shown in fig. 2, the present invention provides an audio link self-checking method, including:
step 1, the main control unit sends the self-checking audio to the coding and decoding unit to obtain the file header parameters of the self-checking audio.
In this embodiment, the header parameters include, but are not limited to, a system sampling rate and a sampling bit number.
The main control unit communicates with the encoding and decoding unit through I2S.
The frequency f of the self-test audio is lower than 20Hz, preferably 5 Hz. The audio frequency of the frequency band is inaudible to human ears, and noise is prevented from being generated in the process of audio self-checking.
The sampling rate fs of the system is 44.1KHz, and the sampling bit number Bs is 16 bits.
And 2, decoding the self-checking audio by the encoding and decoding unit to obtain a first self-checking audio analog signal, amplifying by the power amplification unit to obtain a second self-checking audio analog signal, and broadcasting by a loudspeaker.
The second self-checking audio analog signal is an amplified signal of the first audio analog signal, and the amplification factor of the second self-checking audio analog signal is determined by the power amplification unit.
And 3, feeding the second self-checking audio analog signal back to the coding and decoding unit for coding, generating a self-checking coding signal and sending the self-checking coding signal to the main control unit.
The second self-checking audio analog signal amplified by the power amplification unit is input to the coding and decoding unit through the feedback link, sampled, quantized and coded, and sent to the main control unit for processing in an I2S format.
And 4, generating a self-checking comparison audio by the main control unit according to the self-checking coding signal in a preset format.
And 5, performing spectrum analysis on the self-checking comparison audio through Fourier transform.
In this embodiment, the step 5 includes:
step 501, determining the number of first sampling points according to the frequency of the self-checking audio and the system sampling rate.
The number C1 of the first sampling points is fs/f, where fs is the system sampling rate and f is the frequency of the self-test audio.
For example, the self-test audio is a sine wave with a frequency of 5Hz and a period of 0.2s, and the number of first sampling points C1 in one period is 44.1k/5 is 8.81 k.
Generally, in order to ensure the accuracy of data, data of multiple periods generally need to be sampled in practical application, data of sampling points can be multiplied, so that the data quantity of the sampling points needs to be processed and also can be multiplied when Fourier transform is performed, the Fourier transform is floating point operation, the CPU utilization rate is greatly improved, the calculation time is longer, the fast completion of the self-check of the whole system is not facilitated, and the user experience is influenced.
And 502, determining the number of second sampling points according to the number of the first sampling points and the frequency reduction multiple of the system sampling rate.
And in order to give consideration to the system efficiency and the data accuracy, the sampling rate of the system is subjected to frequency reduction to obtain the sampling rate of a frequency reduction system.
In this embodiment, the second number of sampling points C2 is C1/R, where C1 represents the first number of sampling points, and R represents the down-conversion multiple of the system sampling rate.
For example, the down-conversion multiple is 100, that is, 1 sample is extracted from every 100 first samples as the second sample, that is, C2 ═ C1/R ═ 8.81k/100 ═ 88.1.
And 503, determining a sampling period according to the stored number of the sampling points and the number of the second sampling points.
In this embodiment, the sampling period Ts is k/C2, where k is the number of sample points to be stored, and C2 is the second number of sample points.
For example, if the number k of sample point storages is 512, the sampling period Ts is 512/88.1 is 5.8.
And step 504, determining each input value of Fourier transform according to each sampling value and sampling digit.
In the present embodiment, each input value Wi of the fourier transform is Vi/2Bs(i ═ 1,2,3 … k), where Vi denotes each sample value and Bs is the number of sample bits.
And 505, performing fourier transform on each input value subjected to fourier transform to obtain a real part and an imaginary part of each input value.
In specific implementation, a 2-point DFT disc algorithm is adopted, which is the prior art and is not described herein again.
Step 506, obtaining the amplitude array by performing modulo calculation on the real part and the imaginary part of each input value.
And step 507, acquiring a subscript corresponding to the maximum amplitude value in the amplitude value array.
In specific implementation, the maximum amplitude value and the corresponding subscript in the amplitude value array can be obtained by adopting a bubble sorting method.
And step 508, calculating corresponding frequency according to the subscript.
In order to satisfy the data accuracy and reduce the data amount to be calculated, the accuracy P of the fourier transform frequency point needs to be a suitable value, so that the frequency accuracy is within 0.5Hz, in this embodiment, the accuracy P is 0.2Hz, and then the sampling rate average number N of the frequency reduction system can be calculated according to the following accuracy calculation formula:
p is (fs/R)/N, where P represents the accuracy of the fourier transform frequency point, fs represents the system sampling rate, N represents the number of times the down-converted system sampling rate is averaged, and R is a multiple of the down-conversion.
In the present embodiment, the frequency fBST＝[(fs/R)*(num+1)]and/N, wherein fs is the system sampling rate, R is the preset system sampling rate frequency reduction multiple, num is the subscript value corresponding to the maximum amplitude value, and N is the frequency-reduction system sampling rate average frequency.
And 6, comparing the frequency spectrum of the self-checking comparison audio with the frequency spectrum of the self-checking audio, judging whether the audio is normal or not, and prompting the comparison result.
When the comparison result is normal, the driver is prompted in a voice or text mode that the fault voice prompt function is normal, otherwise, the driver is prompted that the fault voice prompt function is abnormal, and maintenance is performed in time.
The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention.
Claims (9)
1. An audio link self-checking method, comprising:
s1, the main control unit sends the self-checking audio to the coding and decoding unit to obtain the file header parameters of the self-checking audio;
s2, decoding the self-checking audio by the encoding and decoding unit to obtain a first self-checking audio analog signal, amplifying by the power amplification unit to obtain a second self-checking audio analog signal, and broadcasting by a loudspeaker;
s3, feeding the second self-checking audio analog signal back to the coding and decoding unit for coding, generating a self-checking coding signal and sending the self-checking coding signal to the main control unit;
s4, the main control unit generates a self-checking comparison audio according to the self-checking coded signal and a preset format;
s5, carrying out spectrum analysis on the self-checking comparison audio through Fourier transform;
s6, comparing the frequency spectrum of the self-checking comparison audio with the frequency spectrum of the self-checking audio, judging whether the audio is normal or not, and prompting the comparison result;
the S5 includes:
s501, determining the number of first sampling points according to the frequency of the self-checking audio and the system sampling rate;
s502, determining the number of second sampling points according to the number of the first sampling points and the frequency reduction multiple of the system sampling rate;
s503, determining a sampling period according to the number of the stored sampling points and the number of the second sampling points;
s504, determining each input value of Fourier transform according to each sampling value and sampling digit;
s505, carrying out Fourier transform on each input value subjected to Fourier transform to obtain a real part and an imaginary part of each input value;
s506, performing modulus calculation on the real part and the imaginary part of each input value to obtain a magnitude array;
s507, obtaining a subscript corresponding to the maximum amplitude in the amplitude array;
and S508, calculating corresponding frequency according to the subscript.
2. The audio link self-test method of claim 1, wherein the first sampling point number C1 is fs/f, where fs is a system sampling rate and f is a frequency of the self-test audio.
3. The audio link self-checking method of claim 1, wherein the second number of samples C2 is C1/R, where C1 represents the first number of samples and R represents a down-conversion multiple of the system sampling rate.
4. The audio link self-checking method according to claim 1, wherein the sampling period Ts is k/C2, where k is the number of sample points to be saved and C2 is the second number of sample points.
5. The audio link self-test method of claim 1, wherein each input value Wi of the fourier transform is Vi/2Bs(i ═ 1,2,3 … k), where Vi denotes each sample value and Bs is the number of sample bits.
6. Audio link self-checking method according to claim 1, characterized in that said frequency fBST＝[(fs/R)*(num+1)]and/N, wherein fs is the system sampling rate, R is the preset system sampling rate frequency reduction multiple, num is the subscript value corresponding to the maximum amplitude value, and N is the frequency-reduction system sampling rate average frequency.
7. The audio link self-checking method of claim 1, wherein the header parameters include a system sampling rate and a number of sampling bits.
8. The audio link self-test method of claim 1, wherein the frequency of the self-test audio is below 20 Hz.
9. The audio link self-checking method of claim 1, wherein the main control unit and the encoding and decoding unit communicate via I2S.
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| CN109348363A (en) * | 2018-08-31 | 2019-02-15 | 西安中兴新软件有限责任公司 | A kind of audio-frequency detection and device, storage medium |
| CN110540120B (en) * | 2019-09-12 | 2021-10-15 | 日立楼宇技术（广州）有限公司 | Self-checking system of elevator intercom equipment, elevator, self-checking method and storage medium |
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| CN201854404U (en) * | 2010-09-01 | 2011-06-01 | 上海通用汽车有限公司 | Audio signal acquisition and analysis system for vehicle-mounted sound system |
| CN103267568A (en) * | 2013-05-29 | 2013-08-28 | 哈尔滨工业大学 | Voice online detection method for automobile electronic control unit |
| CN103747407A (en) * | 2013-12-27 | 2014-04-23 | 深圳英飞拓科技股份有限公司 | Audio module automatic test method based on FFT frequency sweep |
| CN104485117A (en) * | 2014-12-16 | 2015-04-01 | 福建星网视易信息系统有限公司 | Method and system for detecting sound recording equipment |
| CN105675306A (en) * | 2016-01-12 | 2016-06-15 | 天津理工大学 | Self-testing method and system for automobile |
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| US6968564B1 (en) * | 2000-04-06 | 2005-11-22 | Nielsen Media Research, Inc. | Multi-band spectral audio encoding |
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| CN201854404U (en) * | 2010-09-01 | 2011-06-01 | 上海通用汽车有限公司 | Audio signal acquisition and analysis system for vehicle-mounted sound system |
| CN103267568A (en) * | 2013-05-29 | 2013-08-28 | 哈尔滨工业大学 | Voice online detection method for automobile electronic control unit |
| CN103747407A (en) * | 2013-12-27 | 2014-04-23 | 深圳英飞拓科技股份有限公司 | Audio module automatic test method based on FFT frequency sweep |
| CN104485117A (en) * | 2014-12-16 | 2015-04-01 | 福建星网视易信息系统有限公司 | Method and system for detecting sound recording equipment |
| CN105675306A (en) * | 2016-01-12 | 2016-06-15 | 天津理工大学 | Self-testing method and system for automobile |
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