An ultrasonic gas meter acquisition board consistency detection system and method thereof

Abstract

The application discloses an ultrasonic gas meter acquisition board consistency detection system and a method thereof, and relates to an ultrasonic gas meter acquisition board consistency detection system, which comprises a synchronization module, a control module and an acquisition module. The synchronization module is connected with the control module and the acquisition module respectively and is used for providing synchronization signals to the control module and the acquisition module. The control module is used for receiving waveform data and storing, and outputs reading instructions after a preset delay according to the synchronization signals. A signal generation module is connected with the control module and is used for converting the waveform data into analog excitation signals and outputting the analog excitation signals to the measured meter acquisition board in response to the reading instructions. The acquisition module is used for collecting response signals generated by the measured meter acquisition board under the excitation of the analog excitation signals according to the synchronization signals, so that the output of the analog excitation signals is synchronized with the collection of the response signals. A processing module is connected with the acquisition module and is used for extracting characteristic parameters of the response signals and outputting a consistency detection result according to the comparison result of the characteristic parameters and reference parameters.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic gas meter testing technology, and in particular to an ultrasonic gas meter acquisition board consistency testing system and method. Background Technology

[0002] Ultrasonic gas meters measure the flow of ultrasound in both forward and reverse directions within the gas duct using a transducer, and calculate the flow velocity and flow rate based on the propagation time difference. The metering acquisition board, as the core component of an ultrasonic gas meter, typically includes a transducer excitation circuit, a receiver protection circuit, an analog front-end circuit, a gain adjustment circuit, a filter amplification circuit, an ADC sampling circuit, and a metering timing control circuit. During production, metering acquisition boards of the same model may exhibit inconsistencies in the amplitude, phase, arrival time, noise, and spectral characteristics of the received echoes due to factors such as transducer interface device discreteness, analog front-end gain deviation, filter parameter deviation, welding defects, sampling clock deviation, or calibration parameter errors. This inconsistency can affect the overall metering accuracy and product consistency.

[0003] Currently, there are related technologies for testing ultrasonic gas metering modules. For example, patent CN118190115A discloses a testing device and method for ultrasonic gas metering modules. The device includes: a mechanical testing structure base, a mechanical testing structure frame, a manual execution structure, a display screen, a slot for the metering module under test, a fan, a lithium battery, a main control board, an AC power interface, testing probes, connecting harnesses, a power switch, and connecting harnesses. The main control board MCU in the testing device also includes a testing device status value acquisition module, a metering module under test position determination module, and a metering module under test testing module. The above patent aims to accurately locate the fault points of the metering module during the production process, facilitating repair and preventing defective products from leaving the factory. However, this type of solution mainly focuses on fault location at the mechanical structure level and module-level continuity detection. Its detection relies on module position judgment and status value acquisition. It fails to perform fine measurement and consistency comparison of electrical performance parameters (such as amplitude, phase, propagation time difference, noise and spectral characteristics, etc.) of the analog front-end circuit of the metering acquisition board. Furthermore, the real-time transmission jitter of the communication interface of this type of solution will affect the accuracy of the judgment of signal arrival time and phase.

[0004] Therefore, how to achieve highly repeatable and accurate automated consistency testing of the analog front-end circuit and metering timing-related circuit of the ultrasonic gas meter metering acquisition board at the board level has become an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an ultrasonic gas meter acquisition board consistency detection system and method. This system uses FPGA local RAM to play back ultrasonic equivalent standard waveforms, combined with a unified clock, programmable delay, readback verification, and automated feature comparison to achieve consistency screening of the meter acquisition board.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An ultrasonic gas meter acquisition board consistency detection system includes:

[0008] The synchronization module is connected to both the control module and the acquisition module, and is used to provide synchronization signals to the control module and the acquisition module respectively;

[0009] The control module is used to receive and store waveform data, and output a read command after a preset delay according to the synchronization signal; wherein the waveform data is equivalent waveform data used to simulate the ultrasonic transducer's transmitted signal or received echo signal;

[0010] The signal generation module, connected to the control module, is used to convert waveform data into analog excitation signals in response to read commands and output them to the measurement acquisition board under test.

[0011] The acquisition module is used to acquire the response signal generated by the metering acquisition board under test under the excitation of the analog excitation signal, so as to synchronize the output of the analog excitation signal with the acquisition of the response signal.

[0012] The processing module, connected to the acquisition module, is used to extract the feature parameters of the response signal and output the consistency detection result based on the comparison between the feature parameters and the reference parameters.

[0013] Furthermore, it also includes:

[0014] The configuration module, connected to the control module, is used to send waveform data and detection configuration information to the control module.

[0015] The storage module, connected to the processing module, is used to store reference parameters.

[0016] Furthermore, the control module includes:

[0017] Waveform storage subunit, used to store the written waveform data;

[0018] The verification subunit is used to verify the stored waveform data and output a stop command to the signal generation module when the verification fails.

[0019] The timing control subunit is used to receive the synchronization signal and, after a preset delay, control the signal generation module to start the output of the analog excitation signal.

[0020] Furthermore, the verification subunit verifies the stored waveform data using CRC verification and readback verification; wherein readback verification involves comparing the stored waveform data with the original waveform data point by point.

[0021] Furthermore, the signal generation module includes:

[0022] The digital-to-analog converter subunit is used to convert waveform data into analog signals;

[0023] The attenuation subunit, connected to the digital-to-analog converter subunit, is used to attenuate the amplitude of the analog signal in order to output an analog excitation signal.

[0024] Furthermore, the signal generating module also includes:

[0025] The differential drive subunit is connected to the digital-to-analog converter subunit and the attenuation subunit, respectively, and is used to convert analog signals into differential signals;

[0026] The filtering subunit is connected to the differential drive subunit and the attenuation subunit respectively, and is used to perform low-pass filtering on the differential signal.

[0027] Furthermore, the synchronization module includes:

[0028] Clock source subunit, used to generate reference clock signal;

[0029] The trigger subunit, connected to the clock source subunit, is used to generate a synchronization signal based on the reference clock signal and output the synchronization signal to the control module and the acquisition module respectively.

[0030] Furthermore, the processing module includes:

[0031] The feature extraction subunit is used to preprocess the response signal and extract multiple feature parameters to form the feature vector to be measured.

[0032] The first judgment subunit is used to compare each feature parameter in the feature vector to be tested with the corresponding preset judgment threshold. When any feature parameter exceeds the corresponding preset threshold, it is judged as unqualified.

[0033] The second determination subunit is used to calculate the comprehensive score between each feature parameter in the feature vector to be tested and the reference parameter when the first determination subunit does not determine that it is unqualified, and output the detection result based on the comprehensive score.

[0034] Furthermore, the reference parameters stored in the storage unit are a baseline response database.

[0035] Correspondingly, a method for detecting the consistency of an ultrasonic gas meter acquisition board is also provided, including:

[0036] Receive and store waveform data; wherein the waveform data is equivalent waveform data used to simulate the transmitted signal or received echo signal of an ultrasonic transducer;

[0037] Receive the provided synchronization signal and output a read command after a preset delay based on the synchronization signal;

[0038] In response to a read command, the waveform data is converted into an analog excitation signal and output.

[0039] Based on the response signal generated by the synchronization signal under the excitation of the analog excitation signal, the output of the analog excitation signal is synchronized with the acquisition of the response signal;

[0040] Extract the characteristic parameters of the response signal, compare the characteristic parameters with the reference parameters, and output the consistency detection result based on the comparison result.

[0041] Compared with existing technologies, the detection target of this invention is limited to the ultrasonic gas meter metering acquisition board. The standard excitation is aligned with the ultrasonic transducer's transmission, reception of echoes, and bidirectional propagation time difference scenario. The standard waveform is played back locally by the FPGA, and the communication interface only participates in configuration, reducing jitter. CRC, readback verification, and out-of-bounds protection improve data reliability. Programmable delay and starting address offset facilitate dual-channel metering phase and time compensation. The unified algorithm outputs detection conclusions, making it suitable for rapid screening and quality traceability in ultrasonic gas meter production lines. Attached Figure Description

[0042] Figure 1 This is a flowchart of a consistency test for an ultrasonic gas meter acquisition board provided in Embodiment 1;

[0043] Figure 2 This is a flowchart of response feature comparison and anomaly protection provided in Example 1. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0045] The purpose of this invention is to address the shortcomings of existing technologies by providing an ultrasonic gas meter acquisition board consistency detection system and method.

[0046] Example 1

[0047] This embodiment provides an ultrasonic gas meter acquisition board consistency detection system, such as... Figures 1-2 As shown, it includes a synchronization module 11, a control module 12, a signal generation module 13, an acquisition module 14, a processing module 15, a configuration module 16, and a storage module 17.

[0048] The configuration module 16 is connected to the control module 12 and is used to send waveform data and detection configuration information to the control module 12.

[0049] Storage module 17 is connected to processing module 15 and is used to store reference parameters;

[0050] The synchronization module 11 is connected to the control module 12 and the acquisition module 14 respectively, and is used to provide synchronization signals to the control module 12 and the acquisition module 14 so that the output of the analog excitation signal and the acquisition of the response signal have a deterministic timing relationship.

[0051] The control module 12 is used to receive and store waveform data, and output a read command after a preset delay according to the synchronization signal; wherein the waveform data is equivalent waveform data used to simulate the ultrasonic transducer's transmitted signal or received echo signal;

[0052] The signal generation module 13 is connected to the control module 12 and is used to convert waveform data into analog excitation signals in response to reading commands and output them to the measurement acquisition board under test.

[0053] The acquisition module 14 is used to acquire the response signal generated by the metering acquisition board under test under the excitation of the analog excitation signal according to the synchronization signal;

[0054] The processing module 15 is connected to the acquisition module 14 and is used to extract the feature parameters of the response signal and output the consistency detection result based on the comparison result between the feature parameters and the reference parameters.

[0055] In this embodiment, the configuration module 16 is a host computer with a human-computer interaction interface. The host computer and the control module 12 are connected through any one of the following communication methods: serial port, USB interface or Ethernet interface. The host computer encapsulates waveform data, detection configuration information, judgment threshold, etc. according to the communication frame format and sends them to the control module 12 through the above communication method.

[0056] The communication frame includes a frame header, length field, command field, payload field, and CRC check field; the detection configuration information includes detection mode parameters, sampling rate parameters, delay count parameters, playback length parameters, channel start address parameters, and judgment threshold parameters.

[0057] In this embodiment, the synchronization module 11 includes a clock source subunit and a trigger subunit.

[0058] The clock source subunit is used to generate a high-precision, low-jitter reference clock signal. In this embodiment, the clock source subunit is preferably a temperature-compensated crystal oscillator (TCXO) or an oven-controlled crystal oscillator (OCXO), with a frequency stability better than ±1ppm. The output frequency is determined according to the system sampling rate, such as 10MHz, 50MHz, or 100MHz. The reference clock signal is distributed to the control module 12, the signal generation module 13, and the acquisition module 14 as the synchronous operating clock for each module.

[0059] The trigger subunit is connected to the clock source subunit and is used to generate periodic synchronous trigger pulses according to the reference clock signal. In this embodiment, the trigger subunit can be triggered by software or an external trigger button. When the trigger subunit receives the start command, the trigger subunit outputs a synchronization signal at the next reference clock edge and outputs the synchronization signal to the control module 12 and the acquisition module respectively.

[0060] Through the above configuration, the synchronization module 11 provides the control module 12 and the acquisition module 14 with a common reference clock signal and a synchronization trigger signal, so that the output start point of the analog excitation signal and the acquisition start point of the response signal have a deterministic timing relationship, eliminating the uncertainty of phase and arrival time caused by real-time transmission jitter of the communication interface; wherein the preset delay is a configurable count value in units of the period of the reference clock signal, for example, the delay count value can be set to 0 to 2. 32 Any integer in the range of -1 corresponds to a time delay equal to the count value multiplied by the base clock period.

[0061] The control module 12 in this embodiment uses an FPGA chip and its peripheral circuits. The FPGA has the advantages of parallel processing and precise timing control. The control module 12 includes a waveform storage subunit, a verification subunit, and a timing control subunit.

[0062] The waveform storage subunit uses the block random access memory inside the FPGA. At the start of detection, the control module 12 receives the ultrasonic equivalent standard waveform data sent by the configuration module 16, and after parsing the waveform data through its built-in communication parsing unit, writes the waveform data into the waveform storage subunit. The write address of the waveform data is allocated by the address management logic inside the control module 12 to ensure continuous storage of the waveform data. The waveform data is defined by the carrier frequency, envelope function, amplitude level, inter-channel delay, initial silence segment, and tail attenuation segment. The carrier frequency is from 200 kHz to 700 kHz, the envelope function is a rectangular window, Hanning window, Gaussian window, or measured echo envelope, the amplitude level is from 250 uVpp to 10 mVpp after precise attenuation, and the inter-channel delay is achieved by sampling period integer offset and fractional delay pre-compensation.

[0063] The verification subunit is used to verify the waveform data written to the waveform storage subunit using CRC check and readback check. In this embodiment, the CRC check is performed by the control module 12 after the waveform data is written, calculating the CRC check value of the written data and comparing it with the CRC check field in the communication frame sent by the configuration module 16. If they match, it indicates that the data transmission is error-free; if they do not match, it indicates that an error occurred during the data transmission. The readback check is performed by the control module 12 reading the waveform data stored in the waveform storage subunit one by one and comparing the read data with the original waveform data sent by the configuration module 12 point by point to confirm that the data written to the waveform storage subunit is completely consistent with the original data. When the CRC check or readback check fails, the verification subunit outputs a stop command to the signal generation module 13 and returns an error status information to the configuration module 16, prompting the operator to reload the waveform data.

[0064] The timing control subunit receives the synchronization signal provided by the synchronization module 11 and, after a preset delay, controls the signal generation module 13 to start the output of the analog excitation signal, specifically:

[0065] The timing control subunit includes a programmable delay counter. When the synchronization signal from the synchronization module 11 arrives, the programmable delay counter starts counting. The counting clock is the reference clock signal of the synchronization module 11. When the count value reaches the preset delay count value (delay_ticks), the timing control subunit outputs a start signal to the signal generation module 13. The preset delay count value is a configurable parameter in units of the reference clock period, which is specified by the configuration module 16 when issuing the detection configuration information. Through the above-mentioned programmable delay mechanism, the control module 12 can accurately control the output starting point of the analog excitation signal to simulate the actual propagation time of ultrasonic waves in the gas pipeline.

[0066] In this embodiment, the control module 12 also includes a playback state machine. When the timing control subunit outputs a start signal, the playback state machine reads waveform data sequentially from the waveform storage subunit according to a preset sampling clock frequency, and outputs the read waveform data to the signal generation module 13 in the form of a data stream. The playback state machine controls the reading range according to the start address parameter (start_addr) and sample length parameter (sample_count) issued by the configuration module 16. When the number of read samples reaches the preset sample length, the playback state machine stops reading and waits for the next synchronization trigger.

[0067] The signal generation module 13 in this embodiment includes a digital-to-analog conversion subunit, a differential driving subunit, a filtering subunit, and an attenuation subunit.

[0068] The digital-to-analog converter (DAC) uses a dual-channel high-speed DAC with a sampling rate of 8MSPS to 125MSPS and a resolution of 14-bit or 16-bit. The DAC is connected to the control module 12 and is used to receive the digital waveform data stream output from the playback state machine of the control module 12 and convert the digital waveform data stream into two analog signals (corresponding to the forward and reverse channels). The conversion clock of the DAC is provided by the reference clock signal of the synchronization module 11 to ensure that the DAC is synchronized with the system.

[0069] The differential drive subunit is connected to the digital-to-analog converter subunit and the attenuation subunit respectively. The differential drive subunit includes a differential amplifier, which is used to convert the single-ended analog signal output by the digital-to-analog converter subunit into a differential signal. The differential signal transmission mode can effectively suppress common-mode interference, improve the anti-interference capability of signal transmission, and ensure the integrity of the analog excitation signal during transmission.

[0070] The filtering subunit is connected to the differential driving subunit and the attenuation subunit respectively. The filtering subunit includes a low-pass reconstruction filter, which is used to perform low-pass filtering on the differential signal output by the differential driving subunit to filter out high-frequency sampling noise and image frequency components generated during the digital-to-analog conversion process and reconstruct a smooth analog waveform. The cutoff frequency of the low-pass reconstruction filter is set according to the carrier frequency of the waveform data.

[0071] The attenuation subunit is connected to the filtering subunit and is used to precisely attenuate the amplitude of the filtered analog signal to output the analog excitation signal to the measurement acquisition board under test. The attenuation subunit includes a precision resistor voltage divider network or a programmable attenuator. Since the digital-to-analog converter has low-level quantization and zero-point error when outputting small signals, this embodiment adopts the method of first generating a large-amplitude low-distortion signal on the digital-to-analog converter side, and then precisely attenuating it to a microvolt level signal through the attenuation subunit, so as to reduce the impact of quantization error and zero-point drift on signal quality and improve the accuracy of small signal output. The amplitude of the analog excitation signal output by the attenuation subunit can be configured according to the detection requirements, for example, set to multiple levels in the range of 250μVpp to 10mVpp (such as 250μVpp, 500μVpp, 1mVpp, 10mVpp) to simulate the echo signal intensity received by the ultrasonic transducer under different working conditions.

[0072] In this embodiment, the metering acquisition board under test is an ultrasonic gas meter containing a transducer excitation circuit, a receiver protection circuit, an analog front-end circuit, a gain adjustment circuit, a filter amplification circuit, an ADC sampling circuit, and a metering timing control circuit. The metering acquisition board under test establishes an electrical connection with the system through a test fixture, which provides interface connections for the transducer end, receiver end, sampling end, power supply end, and control end.

[0073] After receiving the analog excitation signal, the internal circuit of the measurement acquisition board under test will generate a corresponding response signal. This response signal is output from the sampling end of the measurement acquisition board under test and transmitted to the acquisition module 14 through the test fixture.

[0074] In this embodiment, waveform data is generated in the order of silent segment, excitation segment, propagation delay segment, echo segment, and tail attenuation segment. The excitation segment uses a 500kHz sinusoidal pulse train with 8-32 cycles. The echo segment is obtained by multiplying a carrier of the same frequency with the Hanning window envelope. The peak position of the envelope is used to simulate the echo arrival time. The forward and reverse waveforms share the same carrier and envelope parameters. Coarse delay at the integer sampling point level is achieved by offsetting the starting address, and fine delay of less than one sampling period is achieved by offline interpolation or fractional delay table.

[0075] The acquisition module 14 in this embodiment includes an analog-to-digital conversion subunit and a cache subunit.

[0076] The analog-to-digital conversion subunit uses a dual-channel high-speed analog-to-digital converter (ADC). The sampling rate matches the sampling rate of the digital-to-analog conversion subunit, with a resolution of 12 to 16 bits. The ADC subunit is connected to the sampling terminal of the measurement acquisition board under test and is used to acquire the response signal generated by the measurement acquisition board under test under analog excitation signal. The sampling clock of the ADC subunit is provided by the reference clock signal of the synchronization module 11, and the sampling start point is controlled by the synchronization signal of the synchronization module 11, thereby ensuring that the sampling and excitation output are strictly synchronized.

[0077] The buffer subunit is used to temporarily store the digital response data output by the analog-to-digital conversion subunit. The buffer subunit adopts FIFO memory or dual-port RAM. After buffering a preset number of sampled data, the data is output to the processing module 15. The buffer depth is determined according to the number of sampling points required for one detection, for example, it can be set to 256 to 16384 sampling points.

[0078] In actual testing, the acquisition module 14 and the signal generation module 13 simultaneously receive the synchronization signal from the synchronization module 11, so that the signal generation module 13 starts to output the analog excitation signal and the acquisition module 14 starts to acquire the response signal in time, that is, the time difference between the excitation output start point and the acquisition start point is only determined by the preset delay of the control module 12 and is not affected by communication delay or other random factors.

[0079] In this embodiment, the storage module 17 is connected to the processing module 15 and is used to store reference parameters. The reference parameters are a baseline response database, and the baseline response database is established in the following way:

[0080] Select at least three ultrasonic gas metering acquisition boards that have been verified as qualified by the whole machine flow meter or standard metering tooling as the reference metering acquisition boards; the number of reference metering acquisition boards is preferably three to ten to ensure the representativeness of the statistical data.

[0081] The qualification of the whole machine flow meter includes: under air medium conditions, the whole machine indication error is calibrated according to multiple preset measurement flow points. The multiple measurement flow points include low flow point, medium flow point and high flow point, preferably including at least three flow points selected from Qmin, Qt, 0.2Qmax, 0.4Qmax and Qmax; the indication error of each measurement flow point meets the maximum permissible error requirement of the corresponding metrology level, and when used as a reference metrology acquisition board, the absolute value of the indication error of each measurement flow point is preferably not greater than 0.5%, more preferably not greater than 0.3%, and the indication error of each measurement flow point is made as close to 0 as possible; the repeatability error of repeated measurements at the same flow point is preferably not greater than 0.2%.

[0082] Each reference measurement acquisition board is connected to this testing system. Under the same tooling, load, power supply voltage and temperature conditions, the standard excitation signal is applied by the signal generation module 13. The waveform parameters of the standard excitation signal are set according to the testing requirements.

[0083] The acquisition module 14 acquires the response signals generated by each reference metering acquisition board under the action of the standard excitation signal, and each working condition is repeatedly acquired no less than ten times.

[0084] The processing module 15 extracts multiple characteristic parameters of each response signal.

[0085] The mean and standard deviation of characteristic parameters under each operating condition, along with corresponding temperature parameters, power supply voltage parameters, tooling number parameters, transducer equivalent load number, FPGA firmware version, waveform version, and channel calibration coefficients, are associated and stored to form a benchmark response database. The benchmark response database is versioned according to tooling number, transducer equivalent load number, or production batch number. When the tooling, transducer equivalent load, analog front-end version, or production batch is changed, a new version is generated in the database; when routine inspections reveal that the benchmark board drift exceeds a preset threshold, the current version is suspended and benchmark data is re-acquired.

[0086] In this embodiment, multiple characteristic parameters extracted from multiple reference metering acquisition boards under the same preset operating conditions are statistically processed to calculate the mean and standard deviation of each characteristic parameter. The preset operating conditions include, but are not limited to: at least three amplitude levels (such as 250μVpp, 1mVpp, and 10mVpp), at least two propagation delay conditions, and at least two power supply voltage boundary conditions (such as 90% and 110% of the rated voltage).

[0087] The processing module 15 in this embodiment includes a feature extraction subunit, a first determination subunit, and a second determination subunit.

[0088] The feature extraction subunit is used to preprocess the response signal and extract multiple feature parameters to form the feature vector to be measured. The preprocessing includes DC removal, bandpass filtering, truncation, cross-correlation, etc. The feature parameters include, but are not limited to, amplitude, phase, propagation time difference, arrival time, channel delay difference, zero drift, noise root mean square value, dominant frequency amplitude, spurious amplitude, and peak position.

[0089] The first judgment subunit is used to compare each feature parameter in the feature vector to be measured with the corresponding preset judgment threshold. The preset judgment threshold includes the absolute qualified limits of each feature parameter, such as arrival time deviation greater than 0.5μs, propagation time difference deviation greater than 0.2μs, amplitude deviation greater than 20%, main frequency phase deviation greater than 5 degrees, noise root mean square value greater than twice the reference mean, and spectral spurious higher than the main frequency amplitude -30dBc, etc. When any feature parameter exceeds the corresponding preset threshold, the first judgment subunit directly determines that the metering acquisition board to be measured is unqualified.

[0090] The second judgment subunit is used to calculate the comprehensive score between each feature parameter in the feature vector to be tested and the reference parameter when the first judgment subunit has not exceeded the preset judgment threshold (not judged as unqualified), and outputs the detection result based on the comprehensive score, specifically:

[0091] The second judgment subunit calculates the difference between each feature parameter in the feature vector to be tested and the reference parameter (benchmark mean), and then divides it by the corresponding benchmark standard deviation to obtain the normalized distance of each feature parameter. Then, it performs a weighted summation of each normalized distance according to a preset weight to obtain a comprehensive score. When the comprehensive score is less than the first threshold (e.g., 1.5), it is judged as qualified; when the comprehensive score is greater than or equal to the first threshold and less than or equal to the second threshold (e.g., 1.5 to 2.5), it is judged as a retest or calibration; when the comprehensive score is greater than the second threshold (e.g., 2.5), it is judged as abnormal. The above thresholds can be configured according to different apertures, different transducer frequencies and enterprise internal control standards.

[0092] The overall score can be expressed as S=sum(w) i *d i ), where d i w represents the normalized distance of the i-th feature parameter. iThe weight of the i-th feature parameter is represented by , and the sum of all weights is 1. In a preferred embodiment, the weights of amplitude, phase, propagation time difference, arrival time, channel delay difference, zero drift, noise root mean square value, dominant frequency amplitude, spurious amplitude, and peak position are 0.10, 0.12, 0.18, 0.10, 0.12, 0.06, 0.08, 0.08, 0.08, and 0.08, respectively. When a certain product model is more sensitive to propagation time difference or arrival time, the weights corresponding to propagation time difference, arrival time, or channel delay difference can be increased, and the weights of amplitude-type or spectrum-type features can be decreased accordingly.

[0093] Through the above two-level judgment mechanism, this embodiment can quickly eliminate obviously unqualified test boards by setting a preset judgment threshold, and can also finely classify test boards in the critical state by comprehensive scoring.

[0094] Example 2

[0095] The difference between the ultrasonic gas meter acquisition board consistency detection system provided in this embodiment and the first embodiment is as follows:

[0096] In this embodiment, the control module 12 is also used to monitor the power supply current of the metering acquisition board under test.

[0097] The control module 12 obtains the real-time power current value of the metering acquisition board under test through the power supply terminal of the test fixture. When the power current exceeds the preset range, the control module 12 determines that the metering acquisition board under test has a short circuit or abnormal power consumption, and immediately controls the signal generation module 13 to stop outputting the analog excitation signal to prevent abnormal excitation from damaging the board under test or causing a safety accident.

[0098] The control module 12 also controls the signal generation module 13 to output a safe level or a zero level when the following abnormal conditions occur:

[0099] If the verification subunit fails, the waveform storage subunit address is out of bounds, the waveform data sample length is zero, or the acquisition module 14 is not ready, the control module 12 will output a prohibition signal to the signal generation module 13 when it detects any of the above abnormal states. The digital-to-analog conversion subunit of the signal generation module 13 will stop waveform output, and the output terminal will maintain a zero level or a preset safe median level. At the same time, the control module 12 will return status information containing the error type to the configuration module 16, and the configuration module 16 will prompt the operator on the display interface to check the connection or reload the data.

[0100] Example 3

[0101] This embodiment provides a method for consistency detection of an ultrasonic gas meter metering acquisition board, including:

[0102] One or more ultrasonic gas metering acquisition boards, verified as qualified by a whole-machine flow meter or standard metering fixture, are selected as reference metering acquisition boards. Each reference metering acquisition board is connected to the detection system. Under the same fixture, load, power supply voltage, and temperature conditions, a standard excitation signal is applied by the signal generation module, and the acquisition module collects the response signals generated by each reference metering acquisition board under the standard excitation signal. Each working condition is repeated at least ten times. The processing module extracts multiple characteristic parameters of each response signal. The multiple characteristic parameters extracted by multiple reference metering acquisition boards under the same preset working condition are statistically processed to calculate the mean and standard deviation of each characteristic parameter. The mean, standard deviation, and corresponding working condition parameters, temperature parameters, fixture number parameters, and channel calibration coefficients are associated and stored in the storage module to form a versioned reference response database. This reference response database is versioned according to the fixture number, transducer equivalent load number, or production batch number. When the fixture, transducer equivalent load, or production batch is changed, the reference data is re-acquired and a new version is generated; thus, the reference response database is established.

[0103] The operator installs the ultrasonic gas metering acquisition board to be tested onto the test fixture. The probes or connectors of the test fixture make contact with the transducer end, receiver end, sampling end, power supply end, and control end of the metering acquisition board to be tested, respectively, to form a reliable electrical connection. The test fixture is connected to the signal generation module, acquisition module, and control module through cables. After checking that the connection is correct, the testing process is started.

[0104] The configuration module sends detection configuration information and waveform data to the control module. The operator selects the model to be tested, the test item, and the judgment standard through the human-machine interface of the configuration module. The configuration module generates detection configuration information based on the operator's selection. The detection configuration information includes sampling rate parameters (dac_sample_rate), delay count parameters (delay_ticks), waveform start address parameters (start_addr_a and start_addr_b), waveform sample length parameters (sample_count), amplitude range parameters (amp_range), inter-channel delay parameters, and judgment threshold parameters. The configuration module packages the waveform data and detection configuration information into a communication frame containing a frame header, length, command, payload, and CRC check field, and sends it to the control module via serial port, USB, or Ethernet.

[0105] The communication parsing unit of the control module parses the communication frame, extracts waveform data and detection configuration information, and writes the waveform data into the waveform storage subunit. After writing, the verification subunit performs CRC check and readback check on the stored waveform data. The CRC check calculates the CRC check value of the written data and compares it with the CRC check field in the communication frame. The readback check reads the data stored in the waveform storage subunit one by one and compares it point by point with the original waveform data sent by the configuration module. When both the CRC check and the readback check pass, the control module returns a ready signal to the configuration module. When either check fails, the control module returns an error status to the configuration module, prompting the operator to reload, and controls the signal generation module to maintain a zero-level output, waiting for reloading.

[0106] After receiving the ready signal, the configuration module sends a start command to the synchronization module. The trigger subunit of the synchronization module generates a synchronization signal based on the reference clock signal of the clock source subunit and outputs the synchronization signal to the timing control subunit of the control module and the acquisition module respectively. After receiving the synchronization signal, the timing control subunit of the control module starts counting the programmable delay counter. When the count value reaches the preset delay count value (delay_ticks), the timing control subunit outputs a start signal to the playback state machine. The playback state machine reads the waveform data sequentially from the waveform storage subunit according to the start address parameter and the sample length parameter, and outputs it to the digital-to-analog conversion subunit of the signal generation module at a preset sampling clock frequency. The digital-to-analog conversion subunit converts the digital waveform data into an analog signal, which is then converted into a differential signal by the differential drive subunit, low-pass filtered by the filtering subunit, and precisely attenuated by the attenuation subunit to form an analog excitation signal, which is output to the transducer input terminal of the measurement acquisition board under test.

[0107] After receiving the synchronization signal, the acquisition module waits for a fixed time (synchronized with the preset delay of the control module) and then begins acquiring the response signal generated by the measurement board under test using the same sampling clock as the analog-to-digital conversion subunit. Since the acquisition module and the signal generation module receive the same synchronization signal and the same source clock, there is a deterministic timing relationship between the output starting point of the analog excitation signal and the acquisition starting point of the response signal. This timing relationship is determined solely by the preset delay of the control module. The analog-to-digital conversion subunit of the acquisition module converts the acquired analog response signal into digital response data and stores it in the buffer subunit.

[0108] The processing module reads digital response data from the acquisition module. The feature extraction subunit performs DC removal, bandpass filtering, truncation, and cross-correlation processing on the digital response data, and then extracts multiple feature parameters such as amplitude, phase, propagation time difference, arrival time, channel delay difference, zero drift, noise root mean square value, dominant frequency amplitude, spurious amplitude, and peak position to form a feature vector to be tested. The first judgment subunit compares each feature parameter in the feature vector to be tested with its corresponding preset judgment threshold. If any feature parameter exceeds the corresponding preset threshold, it is judged as unqualified. The second judgment subunit, if the first judgment subunit does not judge as unqualified, compares each feature parameter in the feature vector to be tested with the benchmark response database in the storage module, calculates the normalized distance of each feature parameter (deviation divided by the benchmark standard deviation), and sums them according to preset weights to obtain a comprehensive score. Based on the score range in which the comprehensive score falls, it outputs a qualified, retest, or abnormal result.

[0109] The processing module generates a test report, which includes the board number, model, test time, test waveform data, values ​​of various characteristic parameters, deviation values, and consistency judgment results of the metering acquisition board under test. The test report is presented to the operator through the display interface of the configuration module and can be saved to local storage or uploaded to the production management system to achieve quality traceability.

[0110] This embodiment has the following advantages over the prior art:

[0111] 1. Since the waveform data is pre-stored in the waveform storage subunit of the control module, it can be directly played back from the local source during detection without relying on the communication interface for real-time transmission, thus eliminating the impact of communication jitter on waveform repeatability; the synchronization module provides a common clock and synchronous trigger signal, so that the output start point of the analog excitation signal and the acquisition start point of the response signal have a deterministic timing relationship in each detection, ensuring a high degree of repeatability of the detection results.

[0112] 2. By obtaining a microvolt-level simulated excitation signal through a precision attenuation subunit, it can simulate the weak echo signal actually received by the ultrasonic transducer, making the detection conditions closer to the actual working scenario; the processing module extracts multi-dimensional feature parameters, including amplitude, phase, propagation time difference, arrival time, noise, and spectrum, which can comprehensively evaluate the electrical performance consistency of the metering acquisition board and discover minute anomalies that are difficult to capture by traditional detection methods.

[0113] 3. The dual verification mechanism of CRC check and readback check ensures the integrity of waveform data during transmission and storage; the abnormal protection mechanism stops the output in time under abnormal conditions such as power supply current exceeding the limit, verification failure, and address out of bounds to prevent damage to the board under test or testing equipment.

[0114] 4. The system adopts a two-level judgment mechanism of single hard threshold and comprehensive scoring, which can quickly eliminate obviously unqualified test boards, and can also use statistical methods to finely classify the critical state and output three types of conclusions: qualified, retested, or abnormal, which facilitates production management and quality traceability.

[0115] 5. The benchmark response database adopts version management, recording tooling number, transducer equivalent load number and production batch number to ensure the traceability of testing conditions; the test report records complete test data to provide data support for quality analysis.

[0116] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A consistency detection system for an ultrasonic gas meter acquisition board, characterized in that, include: The synchronization module is connected to both the control module and the acquisition module, and is used to provide synchronization signals to the control module and the acquisition module respectively; The control module is used to receive and store waveform data, and output a read command after a preset delay according to the synchronization signal; wherein the waveform data is equivalent waveform data used to simulate the ultrasonic transducer's transmitted signal or received echo signal; The signal generation module, connected to the control module, is used to convert waveform data into analog excitation signals in response to read commands and output them to the measurement acquisition board under test. The acquisition module is used to acquire the response signal generated by the metering acquisition board under test under the excitation of the analog excitation signal, so as to synchronize the output of the analog excitation signal with the acquisition of the response signal. The processing module, connected to the acquisition module, is used to extract the feature parameters of the response signal and output the consistency detection result based on the comparison between the feature parameters and the reference parameters.

2. The ultrasonic gas meter acquisition board consistency detection system according to claim 1, characterized in that, Also includes: The configuration module, connected to the control module, is used to send waveform data and detection configuration information to the control module. The storage module, connected to the processing module, is used to store reference parameters.

3. The ultrasonic gas meter acquisition board consistency detection system according to claim 1, characterized in that, The control module includes: Waveform storage subunit, used to store the written waveform data; The verification subunit is used to verify the stored waveform data and output a stop command to the signal generation module when the verification fails. The timing control subunit is used to receive the synchronization signal and, after a preset delay, control the signal generation module to start the output of the analog excitation signal.

4. The ultrasonic gas meter acquisition board consistency detection system according to claim 3, characterized in that, The verification subunit verifies the stored waveform data using CRC verification and readback verification. The readback verification involves comparing the stored waveform data with the original waveform data point by point.

5. The ultrasonic gas meter acquisition board consistency detection system according to claim 1, characterized in that, The signal generation module includes: The digital-to-analog converter subunit is used to convert waveform data into analog signals; The attenuation subunit, connected to the digital-to-analog converter subunit, is used to attenuate the amplitude of the analog signal in order to output an analog excitation signal.

6. The ultrasonic gas meter acquisition board consistency detection system according to claim 5, characterized in that, The signal generation module further includes: The differential drive subunit is connected to the digital-to-analog converter subunit and the attenuation subunit, respectively, and is used to convert analog signals into differential signals; The filtering subunit is connected to the differential drive subunit and the attenuation subunit respectively, and is used to perform low-pass filtering on the differential signal.

7. The ultrasonic gas meter acquisition board consistency detection system according to claim 1, characterized in that, The synchronization module includes: Clock source subunit, used to generate reference clock signal; The trigger subunit, connected to the clock source subunit, is used to generate a synchronization signal based on the reference clock signal and output the synchronization signal to the control module and the acquisition module respectively.

8. The ultrasonic gas meter acquisition board consistency detection system according to claim 1, characterized in that, The processing module includes: The feature extraction subunit is used to preprocess the response signal and extract multiple feature parameters to form the feature vector to be measured. The first judgment subunit is used to compare each feature parameter in the feature vector to be tested with the corresponding preset judgment threshold. When any feature parameter exceeds the corresponding preset threshold, it is judged as unqualified. The second determination subunit is used to calculate the comprehensive score between each feature parameter in the feature vector to be tested and the reference parameter when the first determination subunit does not determine that it is unqualified, and output the detection result based on the comprehensive score.

9. The ultrasonic gas meter acquisition board consistency detection system according to claim 2, characterized in that, The reference parameters stored in the storage unit are a baseline response database.

10. A detection method for an ultrasonic gas meter acquisition board consistency detection system according to any one of claims 1-9, characterized in that, include: Receive waveform data and store it; The waveform data is the equivalent waveform data used to simulate the transmitted signal or received echo signal of the ultrasonic transducer. Receive the provided synchronization signal and output a read command after a preset delay based on the synchronization signal; In response to a read command, the waveform data is converted into an analog excitation signal and output. Based on the response signal generated by the synchronization signal under the excitation of the analog excitation signal, the output of the analog excitation signal is synchronized with the acquisition of the response signal; Extract the characteristic parameters of the response signal, compare the characteristic parameters with the reference parameters, and output the consistency detection result based on the comparison result.

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