An online evaluation system for efficiency of a backflow pump based on an ultrasonic cross-correlation method

Abstract

This invention relates to the field of reflux pump efficiency testing technology, and discloses an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation. The system includes: an ultrasonic transmitting module for generating broadband ultrasonic pulses; a frequency control module for regulating the transmission frequency of the ultrasonic signal; a probe placement module for fixing the ultrasonic probes and adjusting the probe spacing; an ultrasonic receiving module for detecting transmitted or reflected signals and performing time-domain sampling; a data processing module for extracting cross-correlation parameters and calculating pump efficiency, flow rate, cross-correlation peak value, and signal-to-noise ratio; and a central control module for determining whether the efficiency parameters meet the standards based on the pump efficiency test results. If the standards are not met, the module provides feedback adjustment to the probe spacing, transmission frequency, or time-domain sampling frequency for the next batch of tests, achieving intelligent optimization of the evaluation process and consistency of results. This invention effectively improves the automation level and measurement stability of online reflux pump efficiency testing.

Description

Technical Field

[0001] This invention relates to the field of reflux pump efficiency testing technology, and more specifically, to an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method. Background Technology

[0002] Ultrasonic cross-correlation methods play a crucial role in fluid velocity measurement and pump efficiency evaluation. Their main function is to enable online, non-invasive measurement of key parameters such as pump efficiency, flow velocity, cross-correlation peak value, and signal-to-noise ratio in reflux pumps, providing a basis for pump operation status monitoring and energy-saving optimization. Existing technologies typically analyze the cross-correlation time delay of ultrasonic signals propagating in the fluid and use time-difference methods or cross-correlation algorithms to calculate flow velocity and efficiency parameters. However, this process involves the coordinated control of multiple measurement conditions, such as probe spacing, transmission frequency, and signal sampling, making the technical aspects complex and placing high demands on the stability of the detection process and the consistency of the results.

[0003] Currently, existing ultrasonic cross-correlation testing systems generally employ manual or semi-automatic parameter setting methods. Probe spacing adjustment, transmission frequency control, and time-domain sampling primarily rely on operator experience for configuration, making it difficult to achieve precise and repeatable control of measurement conditions. During signal acquisition and processing, probe spacing deviations, improper frequency selection, or insufficient sampling can lead to distortion of the extracted cross-correlation parameters, thus affecting the accuracy of the final efficiency parameter calculation. Furthermore, traditional data processing typically relies on fixed cross-correlation models or offline calibration, offering limited adaptability to differences in fluid media, variations in pipeline conditions, and environmental noise interference. In addition, existing systems often lack real-time analysis and feedback adjustment mechanisms based on measurement results; detection quality is generally judged through post-event review, resulting in adjustment lags and batch-to-batch measurement fluctuations.

[0004] It is evident that existing ultrasonic cross-correlation detection technology still has shortcomings in terms of measurement condition control accuracy, signal acquisition stability, model inversion adaptability, and process closed-loop control, making it difficult to guarantee the accuracy of detection results and the efficiency of the process. This not only increases operational complexity and introduces human error but also limits the large-scale application of this technology in online monitoring and statistical process control of industrial pump sets. Therefore, there is an urgent need to provide an online evaluation system for ultrasonic cross-correlation reflux pump efficiency that can achieve intelligent adjustment of measurement conditions, high-quality signal acquisition, adaptive model analysis, and integrate real-time result feedback and closed-loop optimization, in order to solve the problems of measurement instability and poor result repeatability in existing technologies. Summary of the Invention

[0005] In view of this, the present invention proposes an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method, which aims to solve the problems of lack of accuracy and adaptability in the current detection methods in terms of measurement condition control, signal acquisition and processing and result feedback adjustment, resulting in unstable evaluation process and poor repeatability of measurement results.

[0006] This invention proposes an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method, comprising: An ultrasonic transmitting module, which is an ultrasonic transmitter and driver source used to generate broadband ultrasonic pulses; The frequency control module is connected to the ultrasonic transmitting module. The frequency control module is used to control the frequency regulator and adjustment device of the ultrasonic signal frequency. The probe placement module is connected to the frequency control module. The probe placement module is used to fix the ultrasonic probe and adjust the probe spacing of the probe station. An ultrasonic receiving module, connected to a probe arrangement module, is used to detect ultrasonic detectors and time-domain sampling devices that detect reflected or transmitted ultrasonic signals. The data processing module is connected to the ultrasonic receiving module. The data processing module is used to extract cross-correlation parameters and calculate the efficiency parameters of the reflux pump. The efficiency parameters include pump efficiency, flow rate, cross-correlation peak value and signal-to-noise ratio. The central control module is electrically connected to the ultrasonic transmitting module, frequency control module, probe placement module, ultrasonic receiving module, and data processing module. The central control module is used to determine whether the test results meet the standards based on the pump efficiency calculated by the data processing module and the preset efficiency threshold. If the results do not meet the standards, the central control module will adjust one or more of the following parameters for the next batch of tests: probe spacing, transmission frequency, or time-domain sampling frequency, based on the degree of deviation of the pump efficiency and the combined analysis results of other efficiency parameters.

[0007] Furthermore, the central control module includes: The data acquisition unit is used to acquire the values ​​of all efficiency parameters calculated by the data processing module in real time. The model comparison unit is used to compare the pump efficiency obtained by the data acquisition unit with the first preset efficiency and the second preset efficiency, and generate a quality judgment result. The parameter adjustment unit is used to optimize and adjust the transmission frequency of the frequency control module in the next batch of tests based on the detection value of the cross-correlation peak when the model comparison unit determines that the test result meets the standard, or to correct and adjust the process parameters of the corresponding module based on the quality judgment result when the test result does not meet the standard. The model comparison unit determines that the efficiency parameters of the reflux pump meet the standards under the first judgment condition; it determines that the efficiency parameters of the reflux pump need to be corrected at the first stage under the second judgment condition; and it determines that the efficiency parameters of the reflux pump do not meet the standards under the third judgment condition, and determines the reasons for non-compliance based on the flow rate and signal-to-noise ratio data, including: The first criterion is that the pump efficiency is greater than or equal to the first preset efficiency; The second determination condition is that the pump efficiency is less than the first preset efficiency and greater than or equal to the second preset efficiency; The third criterion is that the pump efficiency is less than the second preset efficiency.

[0008] Furthermore, when the parameter adjustment unit determines the optimized adjustment method for the transmission frequency in the next detection batch based on the cross-correlation peak value calculated by the data processing module, it includes: When the cross-correlation peak value is less than the preset lower limit of the cross-correlation peak value, the central control module selects the first frequency increase coefficient δ1 to adjust the transmission frequency to the corresponding value; When the cross-correlation peak value is greater than the preset cross-correlation peak value upper limit, the central control module selects the first frequency reduction coefficient δ2 to adjust the transmission frequency to the corresponding value; When the cross-correlation peak value is between the preset lower limit of the cross-correlation peak value and the preset upper limit of the cross-correlation peak value, the current transmission frequency remains unchanged.

[0009] Furthermore, when a first-level correction is required, the parameter adjustment unit records the difference between the first preset efficiency and the measured pump efficiency as the first-level efficiency difference, and determines the adjustment method for the probe spacing of the probe arrangement module in the next testing batch based on the first-level efficiency difference, including: When the first-level efficiency difference is greater than or equal to the preset first-level difference threshold, the parameter adjustment unit uses the first spacing adjustment coefficient θ1 to linearly increase the probe spacing to the corresponding target spacing value. When the first-level efficiency difference is less than the preset first-level difference threshold, the parameter adjustment unit uses the second spacing adjustment coefficient θ2 to nonlinearly increase the probe spacing to the corresponding target spacing value.

[0010] Furthermore, after determining the target spacing value for the probe spacing in the next testing batch, the parameter adjustment unit enters the secondary judgment process. The difference between the target spacing value and the probe stage safety spacing threshold is recorded as the secondary spacing difference. When determining the adjustment method for subsequent parameters based on the secondary spacing difference, the process includes: When the difference between the two secondary spacings is greater than or equal to zero, the parameter adjustment unit determines to adjust the probe spacing of the next batch of tests to the target spacing value. When the difference between the two-stage spacing is less than zero, the parameter adjustment unit determines to keep the probe spacing unchanged and activates the frequency correction program, selecting the first frequency adjustment coefficient μ1 to adjust the transmission frequency of the frequency regulator to the corresponding value.

[0011] Furthermore, the parameter adjustment unit determines, based on the flow rate and signal-to-noise ratio calculated by the data processing module, when the reflux pump efficiency parameters are not up to standard, the following actions are taken: When the flow rate is greater than or equal to the preset upper limit of flow rate and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the reason is incomplete time domain sampling, and adjusts the time domain sampling frequency of the ultrasonic receiving module in the next detection batch to the corresponding value according to the specific value of the flow rate. When the flow rate is less than the preset upper limit and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is incomplete emission intensity and adjusts the pulse intensity of the ultrasonic emission module in the next batch of tests to the corresponding value according to the specific value of the signal-to-noise ratio. When the flow rate is greater than or equal to the preset upper limit and the signal-to-noise ratio is greater than or equal to the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is probe spacing imbalance and corrects the preset probe spacing of the next batch of tests to the corresponding value according to the coupling relationship between flow rate and signal-to-noise ratio.

[0012] Furthermore, when the parameter adjustment unit determines the adjustment method for the time-domain sampling frequency in the next detection batch based on the calculated flow rate, it includes: When the ratio of the flow velocity to the preset upper limit of the flow velocity is greater than or equal to the first preset ratio, the parameter adjustment unit selects the first frequency coefficient λ1 to adjust the time domain sampling frequency to the corresponding value; When the ratio of the flow velocity to the preset upper limit of the flow velocity is less than the first preset ratio, the parameter adjustment unit selects the second frequency coefficient λ2 to adjust the time domain sampling frequency to the corresponding value.

[0013] Furthermore, when the parameter adjustment unit determines the adjustment method for the pulse intensity in the next detection batch based on the difference between the calculated signal-to-noise ratio and the preset signal-to-noise ratio threshold, it includes: When the difference is greater than or equal to the preset constant difference, the parameter adjustment unit selects the first intensity coefficient τ1 to adjust the pulse intensity to the corresponding value; When the difference is less than the preset constant difference, the parameter adjustment unit selects the second intensity coefficient τ2 to adjust the pulse intensity to the corresponding value.

[0014] Furthermore, when the parameter adjustment unit corrects the current probe spacing, it includes: The parameter adjustment unit establishes a multivariate nonlinear regression model of flow velocity, signal-to-noise ratio and probe spacing, and uses the calculated flow velocity and signal-to-noise ratio as input variables to determine the target correction spacing; The parameter adjustment unit is also used to record the difference vector between the target correction spacing and the current batch spacing as the spacing correction vector, and to determine the correction method based on the magnitude of the spacing correction vector, wherein: When the module length is greater than or equal to the preset module length threshold, the parameter adjustment unit selects the first correction matrix M1 to correct the current spacing; When the module length is less than the preset module length threshold, the parameter adjustment unit uses the second correction matrix M2 to correct the current spacing.

[0015] Furthermore, after the parameter adjustment unit selects either the first correction matrix M1 or the second correction matrix M2 based on the magnitude of the spacing correction vector to complete the probe spacing correction, it also performs closed-loop verification, including: The parameter adjustment unit recalculates the expected cross-correlation peak value and expected signal-to-noise ratio based on the corrected probe spacing, and compares them with the preset verification thresholds respectively. If the expected cross-correlation peak and the expected signal-to-noise ratio both reach the corresponding preset verification threshold, the correction is confirmed to be effective, and the corrected probe spacing is fed back to the probe placement module and stored in the historical database. Otherwise, the correction is deemed invalid, the process reverts to the current batch probe spacing, and the backup frequency adjustment program is activated, using the third frequency adjustment coefficient μ2 to adjust the transmission frequency.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By setting up an ultrasonic transmission module, stable generation and controllable intensity of broadband ultrasonic pulses are achieved, providing a high-quality and consistent excitation signal source for subsequent fluid interaction. Secondly, through the collaboration of the frequency control module and the probe placement module, the ultrasonic transmission frequency can be precisely controlled, and probes can be placed at preset intervals, avoiding frequency deviations and inaccurate probe positioning problems caused by traditional manual adjustments, thereby improving the repeatability and accuracy of cross-correlation measurement conditions. Furthermore, in the ultrasonic receiving module, the cooperation of a high-sensitivity detector and a time-domain sampling device can completely capture the ultrasonic signals propagating in the fluid, ensuring the integrity of the original signal acquisition and a high signal-to-noise ratio. Simultaneously, by setting up a data processing module, cross-correlation parameters can be quickly extracted based on the acquired time-domain signal, and key efficiency parameters such as pump efficiency, flow velocity, cross-correlation peak value, and signal-to-noise ratio can be calculated using cross-correlation algorithms, achieving automated and quantitative analysis from signal to parameter. Finally, the central control module can compare the calculated efficiency parameters with preset standards in real time. When the evaluation results are not up to standard, it can automatically adjust key measurement conditions such as probe spacing, transmission frequency, or time-domain sampling frequency for the next batch of tests based on the degree of pump efficiency deviation and other parameter combinations. This mechanism establishes a closed-loop control path from signal acquisition and parameter extraction to condition optimization, ensuring the adaptive optimization of the evaluation process and the consistency of measurement results, which helps to improve the stability and reliability of online evaluation of reflux pump efficiency. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A functional block diagram of an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method provided in an embodiment of the present invention; Figure 2 This is a schematic flowchart of an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method, provided as an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] like Figures 1-2 As shown in some embodiments of this application, this embodiment provides an online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method, including: an ultrasonic transmitting module, a frequency control module, a probe arrangement module, an ultrasonic receiving module, a data processing module, and a central control module.

[0020] Specifically, the ultrasonic transmitting module includes an ultrasonic transmitter and a drive source for generating broadband ultrasonic pulses; a frequency control module connected to the ultrasonic transmitting module includes a frequency regulator and an adjustment device for controlling the frequency of the ultrasonic signal; a probe placement module connected to the frequency control module includes a probe platform for fixing ultrasonic probes and adjusting the probe spacing; an ultrasonic receiving module connected to the probe placement module includes an ultrasonic detector and a time-domain sampling device for detecting reflected or transmitted ultrasonic signals; a data processing module connected to the ultrasonic receiving module is used to extract cross-correlation parameters and calculate the efficiency parameters of the reflux pump, wherein the efficiency parameters include pump efficiency, flow rate, cross-correlation peak value, and signal-to-noise ratio; a central control module is electrically connected to the ultrasonic transmitting module, the frequency control module, the probe placement module, the ultrasonic receiving module, and the data processing module, and is used to determine whether the test result meets the standard based on the pump efficiency calculated by the data processing module and a preset efficiency threshold, and when the result does not meet the standard, it adjusts one or more of the probe spacing, transmission frequency, or time-domain sampling frequency of the next batch of tests based on the degree of deviation of the pump efficiency and the combined analysis results of other efficiency parameters.

[0021] Understandably, through modular design, a fully intelligent evaluation process is achieved, encompassing signal generation, condition control, data analysis, and result feedback. In the ultrasonic transmission module, the drive source excites the ultrasonic transmitter to generate stable, broadband ultrasonic pulses, providing a high-quality excitation signal for measurement. In the frequency control module, the coordinated action of the frequency regulator and adjustment device allows for precise setting and adjustment of the ultrasonic transmission frequency, providing the necessary and controllable frequency input for cross-correlation measurements. The probe placement module's probe stand precisely fixes the ultrasonic probes and adjusts the probe spacing, ensuring the accuracy and repeatability of the measurement geometry. The ultrasonic receiving module uses a high-sensitivity detector to capture the ultrasonic signal after it has passed through the fluid and performs high-precision digitization using a time-domain sampling device, providing complete and high-fidelity raw data for subsequent analysis. The data processing module, based on the acquired time-domain waveform, quickly extracts parameters such as cross-correlation delay and calculates key efficiency parameters such as pump efficiency, flow rate, cross-correlation peak value, and signal-to-noise ratio using a cross-correlation algorithm. Finally, the central control module compares the calculated pump efficiency with the preset threshold. When the evaluation result is not up to standard, it can automatically adjust the probe spacing, transmission frequency or time domain sampling frequency of the next batch of tests based on the degree of deviation of pump efficiency and the combined analysis of other efficiency parameters, so as to achieve closed-loop optimization of measurement conditions and improve the consistency and reliability of the evaluation.

[0022] In a specific embodiment of this application, the above steps are implemented as follows: An online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation includes an ultrasonic transmitting module, a frequency control module, a probe placement module, an ultrasonic receiving module, a data processing module, and a central control module. The ultrasonic transmitting module includes a piezoelectric ceramic ultrasonic transducer and a high-voltage pulse drive source to generate broadband ultrasonic pulses from 0.5MHz to 5MHz. The frequency control module includes a digital frequency synthesizer and an adjustment device to initialize the ultrasonic signal transmission frequency to 1MHz and allow continuous adjustment. For example, when evaluating a certain type of reflux pump, the probe spacing is initially set to 100mm. The probe placement module uses a high-precision electric slide to fix the ultrasonic probes and allows precise adjustment of the probe spacing within a range of 50mm to 200mm. The ultrasonic receiving module uses a piezoelectric ultrasonic detector and a time-domain sampling card to scan and acquire the transmitted ultrasonic signal. Based on the acquired time-domain signal, the data processing module calculates the efficiency parameters of the reflux pump using a cross-correlation algorithm and a flow velocity inversion model. The central control module compares the calculated pump efficiency with preset thresholds, such as a first preset efficiency of 85% and a second preset efficiency of 75%. When the result does not meet the standard, it can automatically adjust the probe spacing, transmission frequency or sampling frequency of the next detection batch based on the degree of deviation and other parameters, such as flow rate and signal-to-noise ratio, to achieve closed-loop feedback optimization.

[0023] The above scenarios are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0024] Specifically, the central control module includes: a data acquisition unit for acquiring the values ​​of all efficiency parameters calculated by the data processing module in real time; a model comparison unit for comparing the pump efficiency acquired by the data acquisition unit with the first preset efficiency and the second preset efficiency, and generating a quality judgment result; and a parameter adjustment unit for optimizing and adjusting the transmission frequency of the frequency control module in the next batch of tests based on the detection value of the cross-correlation peak when the model comparison unit determines that the test result meets the standard, or for correcting and adjusting the process parameters of the corresponding module based on the quality judgment result when the test result does not meet the standard. The model comparison unit determines that the efficiency parameters of the reflux pump meet the standard under the first judgment condition; determines that the efficiency parameters of the reflux pump need to be corrected at the first level under the second judgment condition; and determines that the efficiency parameters of the reflux pump do not meet the standard under the third judgment condition, and determines the reason for non-compliance based on the flow rate and signal-to-noise ratio data, including: the first judgment condition being that the pump efficiency is greater than or equal to the first preset efficiency; the second judgment condition being that the pump efficiency is less than the first preset efficiency but greater than or equal to the second preset efficiency; and the third judgment condition being that the pump efficiency is less than the second preset efficiency.

[0025] It can be understood that the intelligent closed-loop regulation of the ultrasonic cross-correlation evaluation process is carried out by the central control module. The module internally includes a data acquisition unit, a model comparison unit, and a parameter adjustment unit. The data acquisition unit obtains all efficiency parameters such as the pump efficiency, flow rate, cross-correlation peak value, and signal-to-noise ratio calculated by the data processing module in real time, providing basic data for subsequent judgment and adjustment. The model comparison unit compares the pump efficiency obtained by the data acquisition unit with the first preset efficiency and the second preset efficiency, and generates a quality judgment result according to the preset judgment conditions. Among them, if the pump efficiency is greater than or equal to the first preset efficiency, it is determined that the efficiency parameters meet the standard; if the pump efficiency is between the first preset efficiency and the second preset efficiency, it is determined that a first-level correction is required; if the pump efficiency is lower than the second preset efficiency, it is determined that it does not meet the standard, and the specific reason for non-compliance is confirmed by combining the data of the flow rate and the signal-to-noise ratio. Finally, the parameter adjustment unit performs corresponding adjustments according to the judgment result generated by the model comparison unit: in the case where the evaluation result meets the standard, the transmission frequency of the frequency control module for the next detection batch can be optimized according to the cross-correlation peak value to further improve the measurement stability; in the case of needing correction or non-compliance, the measurement parameters of the corresponding module, such as the probe spacing, transmission frequency, sampling frequency, or pulse intensity, can be corrected and adjusted, so as to achieve the closed-loop optimization control of the evaluation process.

[0026] Specifically, when the parameter adjustment unit determines the optimization adjustment method for the transmission frequency in the next detection batch according to the cross-correlation peak value calculated by the data processing module, it includes: when the cross-correlation peak value is less than the preset cross-correlation peak value lower limit, the central control module selects the first frequency increase coefficient δ1 to adjust the transmission frequency to the corresponding value; when the cross-correlation peak value is greater than the preset cross-correlation peak value upper limit, the central control module selects the first frequency reduction coefficient δ2 to adjust the transmission frequency to the corresponding value; when the cross-correlation peak value is between the preset cross-correlation peak value lower limit and the preset cross-correlation peak value upper limit, the current transmission frequency remains unchanged.

[0027] It can be understood that the dynamic optimization of the frequency control link in the evaluation process is achieved through the parameter adjustment unit. The parameter adjustment unit adjusts the transmission frequency of the next detection batch according to the cross-correlation peak value calculated by the data processing module in real time, so as to optimize the frequency measurement conditions to more accurately characterize the fluid flow rate characteristics. Specifically, when the cross-correlation peak value is lower than the preset lower limit, it indicates that the current transmission frequency may not be able to best stimulate the signal response related to the flow rate. The central control module will select the first frequency increase coefficient δ1 to increase the transmission frequency to the corresponding optimized value; when the cross-correlation peak value is higher than the preset upper limit, in order to avoid introducing noise or non-linear effects due to over-modulation, the central control module will select the first frequency reduction coefficient δ2 to reduce the transmission frequency to the corresponding optimized value; when the cross-correlation peak value is between the preset lower limit and the upper limit, the current transmission frequency remains unchanged, so as to maintain the stability of the measurement conditions.

[0028] Specifically, when a first-level correction is required, the parameter adjustment unit records the difference between the first preset efficiency and the measured pump efficiency as the first-level efficiency difference. Based on the first-level efficiency difference, it determines the adjustment method for the probe spacing of the probe arrangement module in the next testing batch, including: when the first-level efficiency difference is greater than or equal to the preset first-level difference threshold, the parameter adjustment unit uses the first spacing adjustment coefficient θ1 to linearly increase the probe spacing to the corresponding target spacing value; when the first-level efficiency difference is less than the preset first-level difference threshold, the parameter adjustment unit uses the second spacing adjustment coefficient θ2 to non-linearly increase the probe spacing to the corresponding target spacing value.

[0029] Specifically, after determining the target spacing value for the probe spacing in the next batch of tests, the parameter adjustment unit enters the secondary judgment process. The difference between the target spacing value and the probe station safety spacing threshold is recorded as the secondary spacing difference. When determining the adjustment method of subsequent parameters based on the secondary spacing difference, the parameter adjustment unit determines that: when the secondary spacing difference is greater than or equal to zero, the parameter adjustment unit determines to adjust the probe spacing of the next batch of tests to the target spacing value; when the secondary spacing difference is less than zero, the parameter adjustment unit determines to keep the probe spacing unchanged and activates the frequency correction program, using the first frequency adjustment coefficient μ1 to adjust the transmission frequency of the frequency regulator to the corresponding value.

[0030] Understandably, the parameter adjustment unit enables intelligent, closed-loop control of the probe spacing, a crucial geometric condition, during the evaluation process. When a primary correction is required, the parameter adjustment unit first calculates the difference between the preset efficiency and the measured pump efficiency, recording this as the primary efficiency difference. This difference reflects the deviation between the measurement result and the target value, serving as a crucial basis for determining the optimization direction of the probe spacing for the next batch. Based on the primary efficiency difference, the parameter adjustment unit selects different spacing adjustment strategies: when the difference is greater than or equal to a preset threshold, indicating a large deviation, the unit selects a first spacing adjustment coefficient θ1 to linearly increase the probe spacing to the calculated target spacing value in order to more significantly alter the interaction between the ultrasound and the fluid. When the difference is less than the preset threshold, indicating a smaller deviation, the unit selects a second spacing adjustment coefficient θ2 to non-linearly increase the probe spacing to the target spacing value, achieving finer adjustment and avoiding signal distortion due to excessive spacing changes. After determining the target spacing value, the parameter adjustment unit further enters a secondary judgment process to ensure the safety of the adjustment operation. This process compares the target spacing value with the safe spacing threshold of the probe stage's mechanical structure and calculates the secondary spacing difference. If the secondary spacing difference is greater than or equal to zero, it indicates that the target spacing is within the safe range, and the probe spacing of the next batch of tests is adjusted to the target value. If the secondary spacing difference is less than zero, it indicates that the target spacing may exceed the safe mechanical limit. For equipment protection, the parameter adjustment unit keeps the probe spacing unchanged and simultaneously activates the frequency correction program. The transmission frequency of the frequency regulator is adjusted through the first frequency adjustment coefficient μ1 to compensate for the measurement deviation that may be caused by the spacing limitation by changing another dimension of the interaction between ultrasound and fluid, thereby achieving multi-parameter collaborative optimization.

[0031] In a specific embodiment of this application, the above steps are implemented as follows: A parameter adjustment unit is set in the central control module to intelligently adjust the probe spacing of the probe arrangement module and the transmission frequency of the frequency control module when the evaluation result requires first-level correction. During an evaluation process, the data processing module calculates that the current pump efficiency of the return pump is 82%, the first preset efficiency is 85%, and the second preset efficiency is 75%, thus determining that a first-level correction is required. The parameter adjustment unit first records the difference (3%) between the first preset efficiency and the measured pump efficiency as the first-level efficiency difference. If the first-level efficiency difference is greater than or equal to the preset first-level difference threshold (e.g., 2%), the first spacing adjustment coefficient θ1 is selected to linearly increase the probe spacing to the calculated target spacing value (e.g., from 100mm to 120mm); if the first-level efficiency difference is less than the preset first-level difference threshold, the second spacing adjustment coefficient θ2 is selected to non-linearly increase the probe spacing to the corresponding target spacing value (e.g., from 100mm to 110mm). After determining the target spacing value, the parameter adjustment unit enters the secondary judgment process, comparing the target spacing value with the probe stage safety spacing threshold (e.g., 180mm) and calculating the secondary spacing difference. If the secondary spacing difference is greater than or equal to zero, the probe spacing for the next batch of tests is adjusted to the target spacing value; if the secondary spacing difference is less than zero, the probe spacing remains unchanged, and the frequency correction program is activated. The transmission frequency of the frequency regulator is adjusted to the corresponding value (e.g., from the initial 1MHz to 1.2MHz) using the first frequency adjustment coefficient μ1, thereby optimizing the measurement conditions while ensuring equipment safety.

[0032] As can be seen from the above embodiments, the present invention utilizes a parameter adjustment unit combined with a first-level efficiency difference determination and a second-level safety distance determination to achieve intelligent closed-loop adjustment of probe spacing and transmission frequency, thereby dynamically optimizing key measurement parameters in the ultrasonic cross-correlation evaluation process, ensuring the accuracy and stability of the evaluation results, and improving the safety and reliability of the evaluation process.

[0033] The above scenarios are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0034] Specifically, when the parameter adjustment unit determines that the reflux pump efficiency parameters are not up to standard based on the flow rate and signal-to-noise ratio calculated by the data processing module, the following actions are taken: When the flow rate is greater than or equal to the preset upper limit and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is incomplete time-domain sampling and adjusts the time-domain sampling frequency of the ultrasonic receiving module in the next testing batch to the corresponding value based on the specific value of the flow rate; when the flow rate is less than the preset upper limit and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is incomplete transmission intensity and adjusts the pulse intensity of the ultrasonic transmitting module in the next testing batch to the corresponding value based on the specific value of the signal-to-noise ratio; when the flow rate is greater than or equal to the preset upper limit and the signal-to-noise ratio is greater than or equal to the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is probe spacing imbalance and corrects the preset probe spacing of the next testing batch to the corresponding value based on the coupling relationship between flow rate and signal-to-noise ratio.

[0035] Specifically, when the parameter adjustment unit determines the adjustment method for the time-domain sampling frequency in the next detection batch based on the calculated flow rate, it includes: when the ratio of the flow rate to the preset upper limit of the flow rate is greater than or equal to the first preset ratio, the parameter adjustment unit selects the first frequency coefficient λ1 to adjust the time-domain sampling frequency to the corresponding value; when the ratio of the flow rate to the preset upper limit of the flow rate is less than the first preset ratio, the parameter adjustment unit selects the second frequency coefficient λ2 to adjust the time-domain sampling frequency to the corresponding value.

[0036] Specifically, when the parameter adjustment unit determines the adjustment method for the pulse intensity in the next detection batch based on the difference between the calculated signal-to-noise ratio and the preset signal-to-noise ratio threshold, the following applies: when the difference is greater than or equal to the preset constant difference, the parameter adjustment unit selects the first intensity coefficient τ1 to adjust the pulse intensity to the corresponding value; when the difference is less than the preset constant difference, the parameter adjustment unit selects the second intensity coefficient τ2 to adjust the pulse intensity to the corresponding value.

[0037] Specifically, when the parameter adjustment unit corrects the current probe spacing, it includes: establishing a multivariate nonlinear regression model of flow velocity, signal-to-noise ratio, and probe spacing, and using the calculated flow velocity and signal-to-noise ratio as input variables to determine the target correction spacing; the parameter adjustment unit is also used to record the difference vector between the target correction spacing and the current batch spacing as the spacing correction vector, and to determine the correction method according to the magnitude of the spacing correction vector, wherein: when the magnitude is greater than or equal to a preset magnitude threshold, the parameter adjustment unit selects the first correction matrix M1 to correct the current spacing; when the magnitude is less than the preset magnitude threshold, the parameter adjustment unit selects the second correction matrix M2 to correct the current spacing.

[0038] Understandably, the parameter adjustment unit enables intelligent closed-loop optimization and control of signal acquisition, excitation source, and measurement geometry during the evaluation process. When the flow rate and signal-to-noise ratio calculated by the data processing module indicate that the efficiency parameters are not up to standard, the parameter adjustment unit determines the cause of the anomaly based on different combinations of indicators and selects the corresponding adjustment strategy accordingly. Specifically, when the flow rate is too high and the signal-to-noise ratio is too low, the main cause is determined to be insufficient time-domain sampling, leading to the loss of high-frequency or rapidly changing signal components, which in turn affects the extraction of flow rate information. The parameter adjustment unit increases the time-domain sampling frequency of the next detection batch based on the specific value of the flow rate. When the flow rate is normal but the signal-to-noise ratio is low, the main cause is determined to be insufficient ultrasonic pulse intensity, resulting in a decrease in the overall signal-to-noise ratio. The parameter adjustment unit increases the pulse intensity of the next detection batch based on the specific value of the signal-to-noise ratio. When the flow rate is too high and the signal-to-noise ratio is also abnormal, the main cause is determined to be improper probe spacing, which fails to achieve the optimal interaction state between the ultrasonic waves and the fluid. The parameter adjustment unit then corrects the probe spacing based on the coupling relationship between the two. Secondly, for time-domain sampling adjustment, the parameter adjustment unit calculates the ratio of flow velocity to a preset upper limit and selects different frequency coefficients (λ1 or λ2) to adjust the sampling frequency to the corresponding value, thereby ensuring the integrity of signal acquisition. For pulse intensity adjustment, the parameter adjustment unit selects different intensity coefficients (τ1 or τ2) to adjust the pulse intensity to the corresponding value based on the difference between the signal-to-noise ratio and a preset threshold, thereby improving signal quality. Finally, regarding probe spacing correction, the parameter adjustment unit establishes a multivariate nonlinear regression model between flow velocity, signal-to-noise ratio, and probe spacing, using the calculated values ​​as input to determine the target correction spacing. Subsequently, the difference vector between the target spacing and the current spacing is recorded as the spacing correction vector, and the correction method is determined based on its magnitude: when the magnitude is large, the first correction matrix M1 is used for a larger correction; when the magnitude is small, the second correction matrix M2 is used for fine-tuning. This method achieves precise and adaptive control of key measurement geometric parameters.

[0039] In a specific embodiment of this application, the above steps are implemented as follows: When the flow rate and signal-to-noise ratio (SNR) results in the reflux pump efficiency parameters calculated by the data processing module are not up to standard, the parameter adjustment unit in the central control module determines the cause of the anomaly based on different combinations of indicators and selects the corresponding adjustment strategy accordingly. For example: 1. If the measured flow rate is 3.5 m / s (the preset upper limit is 3.0 m / s) and the SNR is 18 dB (the preset threshold is 20 dB, which is less than the threshold), the system determines that the cause is incomplete time-domain sampling. The parameter adjustment unit calculates the ratio of the flow rate to the upper limit (1.167). If the ratio is greater than or equal to the first preset ratio (1.1), the first frequency coefficient λ1 is used to increase the time-domain sampling frequency from 2 MHz to 5 MHz; if it is less than the first preset ratio, the coefficient λ2 is used to fine-tune it to 3 MHz. 2. If the measured flow rate is 2.5 m / s (lower than the upper limit) and the SNR is 18 dB (still less than the threshold), the system determines that the cause is incomplete emission intensity. The parameter adjustment unit calculates the difference between the signal-to-noise ratio (SNR) and the threshold (-2dB). If the absolute value of this difference is greater than or equal to the preset constant difference (1.5dB), the first intensity coefficient τ1 is used to increase the pulse intensity by 20%; if it is less than this difference, the coefficient τ2 is used to increase it by 10%. 3. If the measured flow velocity is 3.2m / s (higher than the upper limit) and the SNR is 22dB (higher than the threshold), the system determines the cause to be probe spacing imbalance. The parameter adjustment unit inputs the flow velocity and SNR into the pre-trained regression model to obtain a target corrected spacing of 130mm (currently 100mm). The spacing correction vector magnitude is calculated (30mm). If the magnitude is greater than or equal to the preset magnitude threshold (25mm), the first correction matrix M1 is used for correction; if it is less than the threshold, the second correction matrix M2 is used for fine-tuning.

[0040] Through the aforementioned dynamic closed-loop adjustment of multiple indicators and strategies, this embodiment achieves precise and coordinated control of signal acquisition, excitation intensity, and measurement geometry during ultrasonic cross-correlation evaluation, significantly improving the accuracy and repeatability of efficiency parameter inversion and reducing batch-to-batch measurement fluctuations. Simultaneously, this method can respond to data processing results in real time, enabling automatic optimization and intelligent control of evaluation conditions, reducing reliance on operator experience, and enhancing evaluation efficiency and automation levels.

[0041] The above scenarios are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0042] In the above embodiments, by setting up an ultrasonic transmitting module, stable broadband ultrasonic pulses are generated, providing a high-quality excitation source for online evaluation. Through the collaboration of the frequency control module and the probe placement module, the required transmission frequency and probe spacing can be precisely adjusted, ensuring the accuracy and repeatability of the basic conditions for cross-correlation measurements. The ultrasonic receiving module achieves high-fidelity time-domain signal acquisition, providing a reliable basis for data analysis. The data processing module enables rapid and automated calculation from raw signals to key efficiency parameters. Finally, the central control module compares the calculation results with preset thresholds and intelligently adjusts the measurement conditions when they are not met, establishing a closed-loop path of "measurement-analysis-optimization." This ensures the adaptive optimization and continuous improvement of the entire evaluation system, effectively enhancing the stability, accuracy, and reliability of the online evaluation of reflux pump efficiency.

[0043] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0044] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0045] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0046] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. An online evaluation system for the efficiency of a reflux pump based on ultrasonic cross-correlation method, characterized in that, include: An ultrasonic transmitting module, which is an ultrasonic transmitter and driver source used to generate broadband ultrasonic pulses; The frequency control module is connected to the ultrasonic transmitting module. The frequency control module is used to control the frequency regulator and adjustment device of the ultrasonic signal frequency. The probe placement module is connected to the frequency control module. The probe placement module is used to fix the ultrasonic probe and adjust the probe spacing of the probe station. An ultrasonic receiving module, connected to a probe arrangement module, is used to detect ultrasonic detectors and time-domain sampling devices that detect reflected or transmitted ultrasonic signals. The data processing module is connected to the ultrasonic receiving module. The data processing module is used to extract cross-correlation parameters and calculate the efficiency parameters of the reflux pump. The efficiency parameters include pump efficiency, flow rate, cross-correlation peak value and signal-to-noise ratio. The central control module is electrically connected to the ultrasonic transmitting module, frequency control module, probe placement module, ultrasonic receiving module, and data processing module. The central control module is used to determine whether the test results meet the standards based on the pump efficiency calculated by the data processing module and the preset efficiency threshold. If the results do not meet the standards, the central control module will adjust one or more of the following parameters for the next batch of tests: probe spacing, transmission frequency, or time-domain sampling frequency, based on the degree of deviation of the pump efficiency and the combined analysis results of other efficiency parameters.

2. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 1, characterized in that, The central control module includes: The data acquisition unit is used to acquire the values ​​of all efficiency parameters calculated by the data processing module in real time. The model comparison unit is used to compare the pump efficiency obtained by the data acquisition unit with the first preset efficiency and the second preset efficiency, and generate a quality judgment result. The parameter adjustment unit is used to optimize and adjust the transmission frequency of the frequency control module in the next batch of tests based on the detection value of the cross-correlation peak when the model comparison unit determines that the test result meets the standard, or to correct and adjust the process parameters of the corresponding module based on the quality judgment result when the test result does not meet the standard. The model comparison unit determines that the efficiency parameters of the reflux pump meet the standards under the first judgment condition; it determines that the efficiency parameters of the reflux pump need to be corrected at the first stage under the second judgment condition; and it determines that the efficiency parameters of the reflux pump do not meet the standards under the third judgment condition, and determines the reasons for non-compliance based on the flow rate and signal-to-noise ratio data, including: The first criterion is that the pump efficiency is greater than or equal to the first preset efficiency; The second determination condition is that the pump efficiency is less than the first preset efficiency and greater than or equal to the second preset efficiency; The third criterion is that the pump efficiency is less than the second preset efficiency.

3. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 2, characterized in that, When the parameter adjustment unit determines the optimized adjustment method for the transmission frequency in the next detection batch based on the cross-correlation peak value calculated by the data processing module, it includes: When the cross-correlation peak value is less than the preset lower limit of the cross-correlation peak value, the central control module selects the first frequency increase coefficient δ1 to adjust the transmission frequency to the corresponding value; When the cross-correlation peak value is greater than the preset cross-correlation peak value upper limit, the central control module selects the first frequency reduction coefficient δ2 to adjust the transmission frequency to the corresponding value; When the cross-correlation peak value is between the preset lower limit of the cross-correlation peak value and the preset upper limit of the cross-correlation peak value, the current transmission frequency remains unchanged.

4. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 3, characterized in that, When a first-level correction is required, the parameter adjustment unit records the difference between the first preset efficiency and the measured pump efficiency as the first-level efficiency difference. Based on this first-level efficiency difference, it determines the adjustment method for the probe spacing of the probe arrangement module in the next testing batch, including: When the first-level efficiency difference is greater than or equal to the preset first-level difference threshold, the parameter adjustment unit uses the first spacing adjustment coefficient θ1 to linearly increase the probe spacing to the corresponding target spacing value. When the efficiency difference of the first stage is less than the preset first stage difference threshold, the parameter adjustment unit selects the second spacing adjustment coefficient θ2 to nonlinearly increase the probe spacing to the corresponding target spacing value.

5. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 4, characterized in that, After determining the target spacing value for the probe spacing in the next testing batch, the parameter adjustment unit enters the secondary judgment process. The difference between the target spacing value and the probe stage safety spacing threshold is recorded as the secondary spacing difference. Based on this secondary spacing difference, the adjustment method for subsequent parameters is determined, including: When the difference between the two secondary spacings is greater than or equal to zero, the parameter adjustment unit determines to adjust the probe spacing of the next batch of tests to the target spacing value. When the difference between the two-stage spacing is less than zero, the parameter adjustment unit determines to keep the probe spacing unchanged and activates the frequency correction program, selecting the first frequency adjustment coefficient μ1 to adjust the transmission frequency of the frequency regulator to the corresponding value.

6. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 5, characterized in that, The parameter adjustment unit determines when the reflux pump efficiency parameters are not up to standard based on the flow rate and signal-to-noise ratio calculated by the data processing module, including: When the flow rate is greater than or equal to the preset upper limit of flow rate and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the reason is incomplete time domain sampling, and adjusts the time domain sampling frequency of the ultrasonic receiving module in the next detection batch to the corresponding value according to the specific value of the flow rate. When the flow rate is less than the preset upper limit and the signal-to-noise ratio is less than the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is incomplete emission intensity and adjusts the pulse intensity of the ultrasonic emission module in the next batch of tests to the corresponding value according to the specific value of the signal-to-noise ratio. When the flow rate is greater than or equal to the preset upper limit and the signal-to-noise ratio is greater than or equal to the preset signal-to-noise ratio threshold, the parameter adjustment unit determines that the cause is probe spacing imbalance and corrects the preset probe spacing of the next batch of tests to the corresponding value according to the coupling relationship between flow rate and signal-to-noise ratio.

7. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 6, characterized in that, When the parameter adjustment unit determines the adjustment method for the time-domain sampling frequency in the next detection batch based on the calculated flow rate, it includes: When the ratio of the flow velocity to the preset upper limit of the flow velocity is greater than or equal to the first preset ratio, the parameter adjustment unit selects the first frequency coefficient λ1 to adjust the time domain sampling frequency to the corresponding value; When the ratio of the flow velocity to the preset upper limit of the flow velocity is less than the first preset ratio, the parameter adjustment unit selects the second frequency coefficient λ2 to adjust the time domain sampling frequency to the corresponding value.

8. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 7, characterized in that, When the parameter adjustment unit determines the adjustment method for the pulse intensity in the next detection batch based on the difference between the calculated signal-to-noise ratio and the preset signal-to-noise ratio threshold, it includes: When the difference is greater than or equal to the preset constant difference, the parameter adjustment unit selects the first intensity coefficient τ1 to adjust the pulse intensity to the corresponding value; When the difference is less than the preset constant difference, the parameter adjustment unit selects the second intensity coefficient τ2 to adjust the pulse intensity to the corresponding value.

9. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 8, characterized in that, When the parameter adjustment unit corrects the current probe spacing, it includes: The parameter adjustment unit establishes a multivariate nonlinear regression model of flow velocity, signal-to-noise ratio and probe spacing, and uses the calculated flow velocity and signal-to-noise ratio as input variables to determine the target correction spacing; The parameter adjustment unit is also used to record the difference vector between the target correction spacing and the current batch spacing as the spacing correction vector, and to determine the correction method based on the magnitude of the spacing correction vector, wherein: When the module length is greater than or equal to the preset module length threshold, the parameter adjustment unit selects the first correction matrix M1 to correct the current spacing; When the module length is less than the preset module length threshold, the parameter adjustment unit uses the second correction matrix M2 to correct the current spacing.

10. The online evaluation system for reflux pump efficiency based on ultrasonic cross-correlation method as described in claim 9, characterized in that, After the parameter adjustment unit selects either the first correction matrix M1 or the second correction matrix M2 based on the magnitude of the spacing correction vector to complete the probe spacing correction, it also performs closed-loop verification, including: The parameter adjustment unit recalculates the expected cross-correlation peak value and expected signal-to-noise ratio based on the corrected probe spacing, and compares them with the preset verification thresholds respectively. If the expected cross-correlation peak and the expected signal-to-noise ratio both reach the corresponding preset verification threshold, the correction is confirmed to be effective, and the corrected probe spacing is fed back to the probe placement module and stored in the historical database. Otherwise, the correction is deemed invalid, and the process reverts to the current batch probe spacing. The backup frequency adjustment program is then activated, and the transmission frequency is adjusted using the third frequency adjustment coefficient μ2.

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