Attenuation starting point identification method, device and equipment based on voltage attenuation rate

Abstract

The invention discloses an attenuation starting point identification method, device and equipment based on a voltage attenuation rate, and relates to the technical field of acoustic vibration testing, and the method comprises the steps: obtaining a noise excitation voltage signal outputted by a signal source and a sound pressure signal outputted by a microphone, and obtaining a voltage-level time sequence; determining a voltage attenuation rate corresponding to each data point in the voltage-level time sequence; creating a voltage attenuation rate change time history curve; and identifying an attenuation starting point corresponding to each attenuation process in the voltage signal, and determining each attenuation starting point as a sound production stopping point corresponding to the sound pressure signal. According to the method, the bottleneck of hindering reverberation time measurement data analysis automation in the prior art is broken through, and the problems of low efficiency, poor accuracy and the like existing in manual identification are solved.

Description

Technical Field

[0001] The present application relates to the field of acoustic vibration testing technology, and in particular to a method, device and equipment for identifying an attenuation starting point based on a voltage attenuation rate. Background Art

[0002] Reverberation time refers to the time required for the spatial average sound energy density in a closed space to decay by 60dB after the sound source stops. Reverberation time is an important parameter in acoustic research, and acoustic parameters such as sound absorption coefficient and sound insulation can be further calculated through reverberation time.

[0003] Specifically, we can create broadband random noise or pseudo-random noise with sufficient signal-to-noise ratio to excite the measured space, and suddenly turn off the sound source after the reverberation field is formed. Then, we can use the microphone to record the entire sound pressure change process from the start of the sound excitation to the decay to the background noise level. Due to the random characteristics of the excitation signal, this process needs to be repeated many times, and the test results are averaged to ensure the accuracy of the reverberation time.

[0004] However, the premise of using the average algorithm to calculate the reverberation time is to synchronize the measurement data of each measurement process according to the attenuation starting point of each measurement process. The existing technology uses manual identification to identify the attenuation starting point to synchronize the measurement data in multiple measurement processes. This method is inefficient and has poor accuracy. Summary of the invention

[0005] In response to the above-mentioned problems and technical needs, the applicant has proposed a method, device and equipment for identifying the attenuation starting point based on the voltage attenuation rate, so as to solve the problems of low efficiency and poor accuracy when synchronizing the attenuation starting points in multiple measurement processes in the prior art, and realize automatic, fast and accurate identification of the attenuation starting point, so as to achieve synchronization of the attenuation starting points in multiple measurement processes and ensure the accuracy of reverberation time calculation. The application breaks through the bottleneck in the prior art that hinders the automation of reverberation time measurement data analysis, and solves the problems of low efficiency and poor accuracy in manual identification.

[0006] The embodiment of the present application provides a method for identifying a decay starting point based on a voltage decay rate, the method comprising:

[0007] Acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously;

[0008] Performing a preprocessing operation on the voltage signal to obtain a voltage level time series;

[0009] Determining a voltage decay rate corresponding to each data point in the voltage level time series;

[0010] Based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point, a voltage decay rate change time history curve is created, wherein the voltage decay rate change time history curve is used to characterize the corresponding relationship between time and voltage decay rate;

[0011] Based on the voltage attenuation rate change time course curve, the attenuation starting point corresponding to each attenuation process in the voltage signal is identified, and each of the attenuation starting points is determined as the sound stopping point corresponding to the sound pressure signal.

[0012] According to an attenuation starting point identification method based on voltage attenuation rate according to an embodiment of the present application, based on the voltage attenuation rate change time course curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal includes:

[0013] Starting from the first data point, determine in turn whether the voltage decay rate corresponding to each data point is less than a preset threshold;

[0014] Obtaining a target position of a data point corresponding to a target situation in the voltage level time series, wherein the target situation includes: starting from a data point where the voltage decay rate is less than a preset threshold value as determined for the first time, searching backward to the first negative peak point;

[0015] Starting from the timestamp corresponding to the target position, determine the timestamp corresponding to the preset time interval, and determine the data point corresponding to the timestamp after the preset time interval as the new first data point, and execute the step of obtaining the target position of the data point corresponding to the target situation in the voltage level time series starting from the first data point until the target situation no longer exists.

[0016] According to a method for identifying a decay starting point based on a voltage decay rate according to an embodiment of the present application, determining the voltage decay rate corresponding to each data point in the voltage level time series includes:

[0017] Starting from the first data point, obtaining a preset number of data points from the voltage level time series based on the time order of the timestamps;

[0018] Perform linear regression analysis on a preset number of data points to obtain the voltage decay rate corresponding to the first timestamp;

[0019] The second data point is determined as the new first data point, and a linear regression analysis is performed on the new preset number of data points to obtain the voltage decay rate corresponding to the second timestamp, until the voltage decay rates corresponding to all timestamps in the voltage level time series are fully calculated.

[0020] According to the attenuation starting point identification method based on voltage attenuation rate according to an embodiment of the present application, before obtaining a preset number of data points from the voltage level time series based on the time sequence of timestamps starting from the first data point, the method further includes:

[0021] Based on the data length calculation formula, the preset number is obtained;

[0022] The data length calculation formula includes:

[0023] nPolyfit=fix(|Δ / d min |·SR)

[0024] Among them, nPolyfit represents the preset number, Δ represents the preset value, which is a constant, and d min Represents the minimum attenuation rate, SR represents the preset downsampling frequency, which is a constant.

[0025] According to a method for identifying a decay starting point based on a voltage decay rate according to an embodiment of the present application, the preprocessing operation includes: a time weighting processing operation, a data format conversion operation, and a data downsampling processing operation;

[0026] The preprocessing operation is performed on the voltage signal to obtain a voltage level time series, including:

[0027] Based on a preset time weighting constant, performing the time weighting processing operation on the voltage signal to obtain a voltage signal after the time weighting processing;

[0028] Based on a preset data format, performing the data format conversion operation on the voltage signal after the time weighting processing to obtain a voltage level signal to be processed;

[0029] Based on a preset downsampling frequency, the data downsampling processing operation is performed on the voltage level signal to be processed to obtain the sparse voltage level time series.

[0030] According to a method for identifying a decay starting point based on a voltage decay rate according to an embodiment of the present application, the time weighting processing operation is performed on the voltage signal based on a preset time weighting constant to obtain a voltage signal after the time weighting processing, including:

[0031] Based on a voltage signal calculation formula including the time weighting constant, obtaining a voltage signal after time weighting processing;

[0032] Wherein, the voltage signal calculation formula includes:

[0033]

[0034] Among them, U wrepresents the voltage signal after the time weighting operation, τ represents the time weighting constant, ξ represents the virtual variable when performing the integral operation, U represents the voltage signal before the time weighting operation, and t represents time.

[0035] According to a method for identifying a decay starting point based on a voltage decay rate according to an embodiment of the present application, the data format conversion operation is performed on the voltage signal after time weighting processing based on a preset data format to obtain a voltage level signal to be processed, including:

[0036] Based on the format conversion formula, a voltage level signal to be processed corresponding to the voltage signal after time weighting processing is obtained;

[0037] Wherein, the format conversion formula includes:

[0038]

[0039] Among them, L w Indicates the voltage level signal to be processed, U r is the preset reference voltage value.

[0040] According to an attenuation starting point identification method based on voltage attenuation rate according to an embodiment of the present application, before obtaining the noise excitation voltage signal output by the signal source, the method further includes:

[0041] Obtain the voltage input channel of the noise excitation signal output by the signal source;

[0042] The step of obtaining the noise excitation voltage signal output by the signal source comprises:

[0043] Based on the voltage input channel, the voltage signal is acquired.

[0044] The embodiment of the present application further provides a device for identifying a decay starting point based on a voltage decay rate, comprising:

[0045] An acquisition module, used to acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously;

[0046] A processing module, used for performing a preprocessing operation on the voltage signal to obtain a voltage level time series;

[0047] A determination module, used to determine the voltage attenuation rate corresponding to each data point in the voltage level time series;

[0048] A creation module, used to create a voltage decay rate change time history curve based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage decay rate change time history curve is used to characterize the corresponding relationship between time and voltage decay rate;

[0049] The identification module is used to identify the attenuation starting point corresponding to each attenuation process in the voltage signal based on the voltage attenuation rate change time curve, and determine each attenuation starting point as the sound stopping point corresponding to the sound pressure signal.

[0050] An embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for identifying the attenuation starting point based on the voltage attenuation rate as described in any one of the above items are implemented.

[0051] An embodiment of the present application further provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of identifying the decay starting point based on the voltage decay rate as described in any of the above items are implemented.

[0052] The attenuation starting point identification method, device and equipment based on voltage attenuation rate provided in the embodiment of the present application are obtained by acquiring the noise excitation voltage signal output by the signal source and the sound pressure signal output by the microphone, and the sound pressure signal and the voltage signal are synchronously collected; the voltage signal is subjected to time weighting processing operation, data format conversion operation and data downsampling processing operation to obtain a voltage level time series; the voltage attenuation rate corresponding to each data point in the voltage level time series is determined; based on the voltage attenuation rate corresponding to each data point and the timestamp corresponding to each data point, a voltage attenuation rate change time series curve is created; based on the voltage attenuation rate change time series curve, the attenuation starting point corresponding to each attenuation process in the voltage signal is identified, and each attenuation starting point is determined as the stop sounding point corresponding to the sound pressure signal. It can be seen that the present application can automatically, quickly and accurately identify the attenuation starting point, break through the bottleneck of automated analysis of reverberation time measurement data, accurately realize the synchronization of attenuation starting points in multiple measurement processes, ensure the accuracy of reverberation time calculation, and solve the problems of low efficiency and poor accuracy in manually identifying attenuation starting points in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 This is one of the flow charts of the attenuation starting point identification method based on the voltage attenuation rate provided in the embodiment of the present application;

[0055] Figure 2It is a schematic diagram of a voltage signal after a time-weighted processing operation provided by an embodiment of the present application;

[0056] Figure 3 is a schematic diagram of a voltage attenuation rate change time course curve provided in an embodiment of the present application;

[0057] Figure 4 This is the second flow chart of the attenuation starting point identification method based on the voltage attenuation rate provided in the embodiment of the present application;

[0058] Figure 5 This is the third flow chart of the attenuation starting point identification method based on the voltage attenuation rate provided in the embodiment of the present application;

[0059] Figure 6 It is a structural schematic diagram of a device for identifying a decay starting point based on a voltage decay rate provided in an embodiment of the present application;

[0060] Figure 7 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] In order to clearly explain the present application, the identification of the attenuation starting point in the prior art is further explained:

[0063] The specific method of calculating the reverberation time using the average algorithm is as follows:

[0064] Each measurement process is synchronized at the attenuation starting point, and the arithmetic mean of the squared sound pressure values ​​measured at each sampling time point is calculated. The calculation result is converted into the sound pressure level (i.e., converted into dB format), and the sound pressure time history curve of the sound pressure level changing with time is calculated by the linear regression method. The attenuation slope of the sound pressure time history curve is calculated to obtain the reverberation time.

[0065] The average algorithm is used to make the obtained sound pressure time history curve smoother and less volatile, which is more conducive to linear regression analysis.

[0066] Specifically, the sound source is turned on at the same time as data recording is started, and the control software automatically controls the signal source to be turned off after a preset time. In order to achieve this function, the control software needs to control the signal source and the data acquisition device at the same time. However, due to the diversity of equipment, it is difficult to control the quality of the measurement data. In addition, this operation can only measure one attenuation process at a time, and manual operation is required to average multiple attenuation processes.

[0067] In order to realize the full automation of reverberation time measurement data analysis, and at the same time realize the specific data traceability function, ensure data quality, and unbind the signal source and data acquisition equipment, the embodiment of the present application provides a method for identifying the attenuation starting point based on the voltage attenuation rate. This method can be applied to smart terminals and servers. Some other descriptions in the embodiments of the present application are for illustrative purposes and are not used to limit the scope of protection of the present application, and will not be described one by one later. The specific implementation of this method is as follows Figure 1 As shown:

[0068] Step 101: Acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone.

[0069] The sound pressure signal and the voltage signal (noise excitation voltage signal) are collected synchronously.

[0070] Step 102: preprocess the voltage signal to obtain a voltage level time series.

[0071] The preprocessing operation includes: time weighting processing operation, data format conversion operation and data downsampling processing operation.

[0072] Step 103, determining the voltage decay rate corresponding to each data point in the voltage level time series.

[0073] Step 104 : creating a voltage decay rate change time course curve based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point.

[0074] The voltage decay rate change time course curve is used to characterize the corresponding relationship between time and voltage decay rate.

[0075] Step 105 , based on the voltage attenuation rate change time course curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal, and determining each attenuation starting point as the sound stop point corresponding to the sound pressure signal.

[0076] Specifically, it may be necessary to perform a preprocessing operation on the sound pressure signal at the same time, so as to correspond the attenuation starting point corresponding to the voltage signal to the sound pressure signal.

[0077] The attenuation starting point identification method based on voltage attenuation rate provided in the embodiment of the present application is obtained by acquiring the noise excitation voltage signal output by the signal source and the sound pressure signal output by the microphone, and the sound pressure signal and the voltage signal are synchronously collected; the voltage signal is subjected to time weighting processing operations, data format conversion operations and data downsampling processing operations to obtain a voltage level time series; the voltage attenuation rate corresponding to each data point in the voltage level time series is determined; based on the voltage attenuation rate corresponding to each data point and the timestamp corresponding to each data point, a voltage attenuation rate change time history curve is created; based on the voltage attenuation rate change time history curve, the attenuation starting point corresponding to each attenuation process in the voltage signal is identified, and each attenuation starting point is determined as the stop sounding point corresponding to the sound pressure signal. It can be seen that the present application can automatically, quickly and accurately identify the attenuation starting point, break through the bottleneck of automated analysis of reverberation time measurement data, accurately realize the synchronization of attenuation starting points in multiple measurement processes, ensure the accuracy of reverberation time calculation, and solve the problems of low efficiency and poor accuracy in manually identifying attenuation starting points in the prior art.

[0078] In a specific embodiment, before obtaining the noise excitation voltage signal output by the signal source, the voltage input channel of the noise excitation signal output by the signal source is obtained. Then, based on the voltage input channel, the voltage signal is obtained. In addition, based on the sound pressure input channel, the sound pressure signal is obtained.

[0079] When measuring the reverberation time, the present application adds a voltage input channel for collecting voltage signals. The attenuation starting point identification method of the present application is implemented for the measurement data of the channel, and the voltage signal output by the channel and the sound pressure signals output by each microphone channel must be collected simultaneously.

[0080] In a specific embodiment, the specific implementation of performing a preprocessing operation on the voltage signal to obtain a voltage level time series includes:

[0081] Based on a preset time weighting constant, a time weighting processing operation is performed on the voltage signal to obtain a time-weighted voltage signal; based on a preset data format, a data format conversion operation is performed on the time-weighted voltage signal to obtain a voltage level signal to be processed; based on a preset downsampling frequency, a data downsampling processing operation is performed on the voltage level signal to be processed to obtain a sparse voltage level time series.

[0082] Specifically, before the voltage signal is preprocessed, parameter values ​​are set based on its actual situation, for example, time weighting constant, downsampling frequency, data length (corresponding to a preset number of data points), attenuation starting point identification threshold (corresponding to the preset threshold drThreshold), time interval (corresponding to the time interval interval, i.e., the interval between the current sound source closing and the next sound source opening).

[0083] Specifically, the setting of the time weighting constant is related to the length of the reverberation time to be measured. According to the provisions of the ISO3382-2 standard, the time weighting constant should be as close to T / 30 as possible. Among them, T is the minimum value of the reverberation time of each frequency band, and the unit is s (seconds).

[0084] This application sets an empirical value based on the provisions of the ISO3382-2 standard and the measurement environment, and the empirical value is obtained through multiple tests.

[0085] Specifically, a data down-sampling processing operation is performed on the voltage level signal to be processed and the sound pressure level signal to be processed.

[0086] According to the ISO3382-2 standard, the time interval between adjacent data points after downsampling should be less than 1.5 times the time weighting constant. At the same time, in order to ensure that there are enough data points when calculating the voltage decay rate, the downsampling frequency range is [max(1 / 1.5τ,1000),f s / 2]. In addition, in order to improve the computational efficiency and reduce the difference operation in the downsampling process, the present application makes (f s / SR) is a positive integer.

[0087] This application sets an empirical value based on the provisions of the ISO3382-2 standard and the measurement environment, and the empirical value is obtained through multiple tests.

[0088] Where τ represents the time weighting constant, f s represents the original sampling frequency of the noise excitation signal, and SR represents the downsampling frequency.

[0089] Specifically, the data length is the length of the data points when the voltage decay rate is calculated by linear regression, and is set according to the number of data points required for decay under the minimum decay rate state. For details, see formula (1):

[0090] nPolyfit=fix(|Δ / d min |·SR)………………(1)

[0091] Wherein, Δ represents a preset value, for example, 10 dB, d min represents the minimum attenuation rate, and fix() represents the function of rounding to zero.

[0092] Specifically, in order to improve the anti-interference energy and calculation efficiency of the attenuation starting point identification, a attenuation starting point identification threshold is preset. During the identification process, the attenuation rate minimum value needs to be identified, and only the local attenuation rate minimum value less than the attenuation starting point identification threshold value will be identified.

[0093] Among them, the minimum attenuation rate is a theoretical value without considering interference and can be obtained through calculation standards. What this application needs to identify is that the minimum value of the attenuation rate is the measured value including various interferences. Usually, |d min | ≥ |d mim-t |.

[0094] Among them, d min-t represents the minimum value of the attenuation rate, that is, the minimum value in the voltage attenuation rate calculated in this application.

[0095] Among them, the value range of the attenuation starting point recognition threshold is usually [0.7d min , 0.9d min , and this application determines the attenuation starting point recognition threshold according to the measurement environment.

[0096] In the reverberation time measurement, the signal source is connected to the power amplifier to drive the sound source, which will inevitably interfere with the voltage signal output by the signal source. Sometimes, during the attenuation process, there will be a rebound and cause secondary attenuation, which will appear as a second negative peak close to d min after the attenuation starting point on the time history curve of the voltage attenuation rate change. Research shows that during the same attenuation process, the moment when the first negative peak point that satisfies the condition of d r < drThreshold is the attenuation starting point we need; and the subsequent negative peak points occur before the signal attenuates to the background level. Among them, d r represents the voltage attenuation rate.

[0097] This application saves multiple attenuation processes in the same data file to reduce operation steps, reduce the probability of errors, and improve the test efficiency. To adapt to the test process, this application adds a parameter, the time interval interval, that is, the time interval from the shutdown of the sound source this time to the startup of the next sound source, with the unit of s (seconds). During the recognition process, after identifying the attenuation starting point of the first attenuation process, move the data pointer backward by the interval time, and continue to search for the first negative peak point that meets the conditions in the subsequent data from the position where the pointer is located, and so on until the search of all data is completed.

[0098] Specifically, the time interval represents the time interval from the shutdown of the current sound source to the startup of the next sound source. To ensure that the sound pressure completely decays, the time interval should be long enough. Usually, it is recommended that interval ≥ 10s, and it can also be set according to the actual situation. It should be noted that once this parameter is set, this setting should also be followed during the measurement operation. If only one attenuation process is recorded for each acquisition during measurement, this parameter does not affect the recognition of the attenuation starting point.

[0099] Among them, interval represents the time interval.

[0100] In a specific embodiment, based on a preset time weighting constant, a time weighting processing operation is performed on a voltage signal to obtain a voltage signal after the time weighting processing. The specific implementation includes:

[0101] Based on a voltage signal calculation formula including a time weighting constant, a voltage signal after time weighting processing is obtained.

[0102] The voltage signal calculation formula is shown in formula (2):

[0103]

[0104] Among them, U w represents the voltage signal after the time weighting operation, τ represents the time weighting constant, ξ represents the virtual variable when performing the integral operation, U represents the voltage signal before the time weighting operation, and t represents time.

[0105] pass Figure 2 The voltage signal after time weighting and format conversion is shown in the example. 0-6.5s represents the background noise before the signal source is turned on, 6.5s is the signal source turned on, the voltage level instantly rises to 85dB, 6.5s-31s, the signal source is stably excited, 31s is the signal source turned off, the voltage level decays exponentially, and 31.7s-40s is the background noise after complete decay.

[0106] In a specific embodiment, based on a preset data format, a data format conversion operation is performed on the voltage signal after time weighting processing to obtain a voltage level signal to be processed. The specific implementation includes:

[0107] Based on the format conversion formula, a voltage level signal to be processed corresponding to the voltage signal after time weighting processing is obtained.

[0108] The format conversion formula is shown in formula (3):

[0109]

[0110] Among them, L w Indicates the voltage level signal to be processed, U r is the preset reference voltage value.

[0111] In a specific embodiment, starting from the first data point, based on the time sequence of the timestamps, before obtaining a preset number of data points from the voltage level time series, a preset number is obtained based on a data length calculation formula.

[0112] The data length calculation formula is shown in formula (4):

[0113] nPolyfit=fix(|Δ / d min |·SR)……………………(4)

[0114] Among them, nPolyfit represents the preset number, Δ represents the preset value, which is a constant, and d min Represents the minimum attenuation rate, SR represents the preset downsampling frequency, which is a constant.

[0115] Specifically, the purpose of downsampling in the present application is to reduce unnecessary calculations and improve the efficiency of recognition operations.

[0116] In a specific embodiment, the specific implementation of determining the voltage decay rate corresponding to each data point in the voltage level time series includes:

[0117] Starting from the first data point, based on the time order of the timestamps, a preset number of data points are obtained from the voltage level time series; a linear regression analysis is performed on the preset number of data points to obtain the voltage decay rate corresponding to the first timestamp; the second data point is determined as the new first data point, and a linear regression analysis is performed on the new preset number of data points to obtain the voltage decay rate corresponding to the second timestamp, until the voltage decay rates corresponding to all timestamps in the voltage level time series are fully calculated.

[0118] Specifically, the least square method is used for each data point in the voltage level time series, and a linear regression analysis is performed to obtain the voltage decay rate corresponding to each time stamp.

[0119] Specifically, the voltage level time series is divided into several continuous but non-overlapping subsequences in chronological order according to preset data, and a linear regression analysis is performed on the data points in each subsequence to obtain the voltage decay rate corresponding to each timestamp. The width of the subsequence is nPolyfit.

[0120] Among them, through Figure 3 The voltage attenuation rate change time curve is schematically displayed, in which the attenuation rate of the background noise and the voltage signal approaches 0dB / s. The peak value of the rising period corresponds to the turn-on moment of the signal source, and the minimum negative peak point of the attenuation period corresponds to the turn-off moment of the signal source, that is, the starting point of attenuation.

[0121] Next, through Figure 4 The calculation of voltage attenuation rate is explained in detail:

[0122] Step 401, obtaining the total number n of data points in the voltage level time series.

[0123] Step 402 , starting from the first data point, linear regression analysis is performed on a preset number of data points to obtain the voltage decay rate corresponding to the first timestamp, and obtain the timestamp id corresponding to the last data point of the current calculation sample.

[0124] Step 403, determine whether id is less than the total number n, if so, execute step 404, otherwise, execute step 405.

[0125] Step 404, determine the second data point of the current calculation sample as the new first data point, extract a preset number of data points for linear regression analysis, obtain the voltage decay rate corresponding to the next timestamp, obtain the timestamp id corresponding to the last data point of the current calculation sample, and return to execute step 403.

[0126] Step 405, ending the voltage decay rate calculation process.

[0127] In a specific embodiment, based on the voltage attenuation rate change time course curve, the specific implementation of identifying each attenuation starting point corresponding to the voltage signal includes:

[0128] Starting from the first data point, obtain the target position of the data point corresponding to the target situation in the voltage level time series; starting from the timestamp corresponding to the target position, determine the timestamp corresponding to the preset time interval, and determine the data point corresponding to the timestamp after the preset time interval as the new first data point, and execute the steps of obtaining the target position of the data point corresponding to the target situation in the voltage level time series starting from the first data point until the target situation does not exist.

[0129] The target situation includes: starting from the data point where the voltage attenuation rate is less than a preset threshold value as a result of the first judgment, searching backward to the first negative peak point.

[0130] Specifically, for a voltage decay rate change time history curve with m data points, the calculation process for identifying the decay starting point is as follows: Figure 5 As shown:

[0131] Step 501, parameter initialization.

[0132] ID0=0,data=d,k=1,id=[],nInterval=SR*interval

[0133] Wherein, ID0 is the position of the decay starting point in d for each decay process calculation; data is the source data for each decay process calculation; k is the decay process counter; id is the calculation result vector, that is, the decay starting point vector for each decay process; nInterval is the number of data points between the calculation starting points of adjacent decay processes; SR is the sampling frequency of the voltage decay rate change time history curve; interval is the time between adjacent decay processes, with the unit of seconds.

[0134] Step 502, find the data points that meet the conditions for the k-th decay process.

[0135] Wherein, starting from the (ID0 + 1)-th data point, find the first negative peak point that satisfies the condition d < drThreshold, and return its position Loc in d; if no data point that meets the conditions is searched, then Loc is empty.

[0136] Step 503, determine whether the search result is empty. If so, execute Step 507; otherwise, execute Step 504.

[0137] Step 504, take the first element in Loc as the k-th element of the calculation result vector id.

[0138] Step 505, recalculate the parameter ID0 and determine the position of the new parameter.

[0139] Wherein, identify the decay starting point for the next decay process.

[0140] Wherein, reset the calculation starting point ID0 = id(k) + nInterval - 1. If ID0 < (m - 3), then continue with the subsequent steps to prepare for the calculation of the next decay process; otherwise, jump out of the loop and the calculation ends.

[0141] Step 506, reset the increment counter, calculate the new source data, and return to execute Step 502.

[0142] Wherein, k = k + 1, and take the voltage decay rate data starting from the (ID0 + 1)-th data point as the source data, that is, data = d(ID0 + 1:end).

[0143] Step 507, the calculation process ends.

[0144] The present application can automatically and accurately identify the starting point of the attenuation rate in the measured data (noise excitation signal), supports any signal source and data acquisition equipment that meets the standard requirements, and solves the problem of limitations on data acquisition equipment in the prior art. In addition, during the data analysis process, each link is closely linked to ensure the accuracy of identifying the starting point of the attenuation rate. The entire process is completed automatically without human intervention, solving the problems of poor accuracy and low efficiency in the prior art caused by manual identification.

[0145] In addition, this application also designs an analysis program, which performs data analysis through a one-click analysis button, and can trace back to each link in the analysis process, thus ensuring the quality of the analysis data.

[0146] The embodiment of the present application also provides a device for identifying a decay starting point based on a voltage decay rate. The specific implementation of the device can refer to the description of the method for identifying a decay starting point based on a voltage decay rate, and the repeated parts will not be repeated. Figure 6 As shown, the device comprises:

[0147] An acquisition module 601 is used to acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously;

[0148] The processing module 602 is used to perform a preprocessing operation on the voltage signal to obtain a voltage level time series;

[0149] A determination module 603 is used to determine a voltage decay rate corresponding to each data point in the voltage level time series;

[0150] A creation module 604 is used to create a voltage decay rate change time history curve based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage decay rate change time history curve is used to characterize the corresponding relationship between time and voltage decay rate;

[0151] The identification module 605 is used to identify the attenuation starting point corresponding to each attenuation process in the voltage signal based on the voltage attenuation rate change time course curve, and determine each attenuation starting point as the sound stopping point corresponding to the sound pressure signal.

[0152] In a specific embodiment, the identification module 605 is used to determine, starting from the first data point, whether the voltage attenuation rate corresponding to each data point is less than a preset threshold value; obtain the target position of the data point corresponding to the target situation in the voltage level time series, wherein the target situation includes: starting from the data point where the first judgment result is that the voltage attenuation rate is less than the preset threshold value, searching backward to the first negative peak point; starting from the timestamp corresponding to the target position, determining the timestamp corresponding to after the preset time interval, and determining the data point corresponding to the timestamp after the preset time interval as the new first data point, and executing the steps of obtaining the target position of the data point corresponding to the target situation in the voltage level time series starting from the first data point until the target situation does not exist.

[0153] In a specific embodiment, the determination module 603 is used to obtain a preset number of data points from the voltage level time series starting from the first data point based on the time order of the timestamps; perform linear regression analysis on the preset number of data points to obtain the voltage decay rate corresponding to the first timestamp; determine the second data point as the new first data point, and perform linear regression analysis on the new preset number of data points to obtain the voltage decay rate corresponding to the second timestamp, until the voltage decay rates corresponding to all timestamps in the voltage level time series are fully calculated.

[0154] In a specific embodiment, the device further includes a data length calculation module, which is used to obtain a preset number based on a data length calculation formula;

[0155] The data length calculation formula includes:

[0156] nPolyfit=fix(|Δ / d min |·SR)

[0157] Among them, nPolyfit represents the preset number, Δ represents the preset value, which is a constant, and d min Represents the minimum attenuation rate, SR represents the preset downsampling frequency, which is a constant.

[0158] In a specific embodiment, the preprocessing operation includes: a time weighting processing operation, a data format conversion operation and a data downsampling processing operation; the processing module 602 is used to perform a time weighting processing operation on the voltage signal based on a preset time weighting constant to obtain a voltage signal after time weighting processing; based on a preset data format, perform a data format conversion operation on the voltage signal after time weighting processing to obtain a voltage level signal to be processed; based on a preset downsampling frequency, perform a data downsampling processing operation on the voltage level signal to be processed to obtain a sparse voltage level time series.

[0159] In a specific embodiment, the processing module 602 is used to obtain a voltage signal after time weighting processing based on a voltage signal calculation formula including a time weighting constant;

[0160] The voltage signal calculation formula includes:

[0161]

[0162] Among them, U w represents the voltage signal after the time weighting operation, τ represents the time weighting constant, ξ represents the virtual variable when performing the integral operation, U represents the voltage signal before the time weighting operation, and t represents time.

[0163] In a specific embodiment, the processing module 602 is used to obtain a voltage level signal to be processed corresponding to the voltage signal after time weighting processing based on a format conversion formula;

[0164] The format conversion formula includes:

[0165]

[0166] Among them, L w Indicates the voltage level signal to be processed, U r is the preset reference voltage value.

[0167] In a specific embodiment, the device acquisition module 602 is further used to acquire a voltage input channel of a noise excitation signal output by a signal source; the acquisition module 602 is used to acquire a voltage signal based on the voltage input channel.

[0168] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7As shown, the electronic device may include: a processor 701, a communication interface 702, a memory 703 and a communication bus 704, wherein the processor 701, the communication interface 702 and the memory 703 communicate with each other through the communication bus 704. The processor 701 may call the logic instructions in the memory 703 to execute the attenuation starting point identification method based on the voltage attenuation rate, the method comprising: obtaining the noise excitation voltage signal output by the signal source and the sound pressure signal output by the microphone, wherein the sound pressure signal and the voltage signal are synchronously collected; performing a preprocessing operation on the voltage signal to obtain a voltage level time series; determining the voltage attenuation rate corresponding to each data point in the voltage level time series; creating a voltage attenuation rate change time history curve based on the voltage attenuation rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage attenuation rate change time history curve is used to characterize the corresponding relationship between time and voltage attenuation rate; based on the voltage attenuation rate change time history curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal, and determining each attenuation starting point as the sound stop point corresponding to the sound pressure signal.

[0169] In addition, the logic instructions in the above-mentioned memory 703 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0170] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by the computer, the computer can execute the attenuation starting point identification method based on the voltage attenuation rate provided by the above-mentioned methods, and the method includes: obtaining a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously; performing a preprocessing operation on the voltage signal to obtain a voltage level time series; determining the voltage attenuation rate corresponding to each data point in the voltage level time series; creating a voltage attenuation rate change time curve based on the voltage attenuation rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage attenuation rate change time curve is used to characterize the corresponding relationship between time and voltage attenuation rate; based on the voltage attenuation rate change time curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal, and determining each attenuation starting point as the stop sounding point corresponding to the sound pressure signal.

[0171] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the attenuation starting point identification method based on the voltage attenuation rate provided in the above-mentioned embodiments, the method comprising: obtaining a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously; performing a preprocessing operation on the voltage signal to obtain a voltage level time series; determining the voltage attenuation rate corresponding to each data point in the voltage level time series; creating a voltage attenuation rate change time history curve based on the voltage attenuation rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage attenuation rate change time history curve is used to characterize the corresponding relationship between time and the voltage attenuation rate; based on the voltage attenuation rate change time history curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal, and determining each attenuation starting point as the stop sounding point corresponding to the sound pressure signal.

[0172] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0173] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0174] Finally, it should be noted that the above is only the preferred implementation of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the scope of protection of the present application.

Claims

1. A method for identifying the attenuation starting point based on voltage attenuation rate, characterized in that: The method comprises: Acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously; Performing a preprocessing operation on the voltage signal to obtain a voltage level time series; Determining a voltage decay rate corresponding to each data point in the voltage level time series; Based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point, a voltage decay rate change time history curve is created, wherein the voltage decay rate change time history curve is used to characterize the corresponding relationship between time and voltage decay rate; Based on the voltage attenuation rate change time course curve, the attenuation starting point corresponding to each attenuation process in the voltage signal is identified, and each of the attenuation starting points is determined as the sound stopping point corresponding to the sound pressure signal.

2. The method for identifying the attenuation starting point based on the voltage attenuation rate according to claim 1, characterized in that: Based on the voltage attenuation rate change time course curve, identifying the attenuation starting point corresponding to each attenuation process in the voltage signal, including: Starting from the first data point, determine in turn whether the voltage decay rate corresponding to each data point is less than a preset threshold; Obtaining a target position of a data point corresponding to a target situation in the voltage level time series, wherein the target situation includes: starting from a data point where the voltage decay rate is less than a preset threshold value as determined for the first time, searching backward to the first negative peak point; Starting from the timestamp corresponding to the target position, determine the timestamp corresponding to the preset time interval, and determine the data point corresponding to the timestamp after the preset time interval as the new first data point, and execute the step of obtaining the target position of the data point corresponding to the target situation in the voltage level time series starting from the first data point until the target situation no longer exists.

3. The method for identifying the attenuation starting point based on the voltage attenuation rate according to claim 1, characterized in that: Determining the voltage attenuation rate corresponding to each data point in the voltage level time series includes: Starting from the first data point, obtaining a preset number of data points from the voltage level time series based on the time order of the timestamps; Perform linear regression analysis on a preset number of data points to obtain the voltage decay rate corresponding to the first timestamp; The second data point is determined as the new first data point, and a linear regression analysis is performed on the new preset number of data points to obtain the voltage decay rate corresponding to the second timestamp, until the voltage decay rates corresponding to all timestamps in the voltage level time series are fully calculated.

4. The method for identifying the attenuation starting point based on the voltage attenuation rate according to claim 3, characterized in that: Before acquiring a preset number of data points from the voltage level time series based on the time sequence of timestamps starting from the first data point, the method further includes: Based on the data length calculation formula, the preset number is obtained; The data length calculation formula includes: nPolyfit=fix(|Δ / d min |·SR) Among them, nPolyfit represents the preset number, Δ represents the preset value, which is a constant, and d min Represents the minimum attenuation rate, SR represents the preset downsampling frequency, which is a constant.

5. The attenuation starting point identification method based on voltage attenuation rate according to any one of claims 1 to 4, characterized in that: The preprocessing operation includes: time weighting processing operation, data format conversion operation and data downsampling processing operation; The preprocessing operation is performed on the voltage signal to obtain a voltage level time series, including: Based on a preset time weighting constant, performing the time weighting processing operation on the voltage signal to obtain a voltage signal after the time weighting processing; Based on a preset data format, performing the data format conversion operation on the voltage signal after the time weighting processing to obtain a voltage level signal to be processed; Based on a preset downsampling frequency, the data downsampling processing operation is performed on the voltage level signal to be processed to obtain the sparse voltage level time series.

6. The method for identifying the attenuation starting point based on the voltage attenuation rate according to claim 5, characterized in that: The step of performing the time weighting processing operation on the voltage signal based on a preset time weighting constant to obtain a voltage signal after the time weighting processing includes: Based on a voltage signal calculation formula including the time weighting constant, obtaining a voltage signal after time weighting processing; Wherein, the voltage signal calculation formula includes: Among them, U w represents the voltage signal after the time weighting operation, τ represents the time weighting constant, ξ represents the virtual variable when performing the integral operation, U represents the voltage signal before the time weighting operation, and t represents time.

7. The method for identifying the decay starting point based on voltage decay rate according to claim 6, characterized in that: The step of performing the data format conversion operation on the voltage signal after the time weighting process based on the preset data format to obtain the voltage level signal to be processed includes: Based on the format conversion formula, a voltage level signal to be processed corresponding to the voltage signal after time weighting processing is obtained; Wherein, the format conversion formula includes: Among them, L w Indicates the voltage level signal to be processed, U r is the preset reference voltage value.

8. The method for identifying the attenuation starting point based on the voltage attenuation rate according to any one of claims 1 to 3, characterized in that: Before obtaining the noise excitation voltage signal output by the signal source, it also includes: Obtain the voltage input channel of the noise excitation signal output by the signal source; The step of obtaining the noise excitation voltage signal output by the signal source comprises: Based on the voltage input channel, the voltage signal is acquired.

9. A device for identifying the decay starting point based on voltage decay rate, characterized in that: The device comprises: An acquisition module, used to acquire a noise excitation voltage signal output by a signal source and a sound pressure signal output by a microphone, wherein the sound pressure signal and the voltage signal are acquired synchronously; A processing module, used for performing a preprocessing operation on the voltage signal to obtain a voltage level time series; A determination module, used to determine the voltage attenuation rate corresponding to each data point in the voltage level time series; A creation module, used to create a voltage decay rate change time history curve based on the voltage decay rate corresponding to each data point and the timestamp corresponding to each data point, wherein the voltage decay rate change time history curve is used to characterize the corresponding relationship between time and voltage decay rate; The identification module is used to identify the attenuation starting point corresponding to each attenuation process in the voltage signal based on the voltage attenuation rate change time curve, and determine each attenuation starting point as the sound stopping point corresponding to the sound pressure signal.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the attenuation starting point identification method based on voltage attenuation rate as described in any one of claims 1 to 8 are implemented.

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