Circuit board functional defect positioning method based on dynamic signal feature extraction

Abstract

The invention discloses a circuit board functional defect positioning method based on dynamic signal feature extraction, which belongs to the technical field of electronic equipment detection, and comprises the following steps: S10, acquiring normal signal data of key nodes of a circuit board, the key nodes comprising a power supply input end, a signal input end and a signal output end; the normal signal data comprises a voltage signal and a current signal; constructing a database about normal signal data; s20, voltage signals and current signals of key nodes of the circuit board are collected, the change rules of the voltage signals and the current signals are analyzed, and the change rules are compared with the database. According to the circuit board fault diagnosis system and method, more comprehensive, accurate and reliable fault diagnosis can be carried out on the circuit board by comprehensively applying methods of signal acquisition, data analysis, fault diagnosis and the like, and the detection quality and reliability of functions of the circuit board are improved.

Description

Technical Field

[0001] This invention relates to the field of electronic equipment testing technology, and in particular to a method for locating functional defects in circuit boards based on dynamic signal feature extraction. Background Technology

[0002] Circuit boards are core components of modern electronic devices, and their reliability directly affects the performance and stability of the equipment. Therefore, it is necessary to test whether the circuit board functions properly.

[0003] Regarding this research, application CN202210898704.X provides a signal testing system, method, assembled printed circuit board, and server. This technical solution includes a signal testing fixture comprising a printed circuit board, test points on the printed circuit board, and an adapter. The test points and the adapter are connected via PCB traces. The assembled printed circuit board has test points on it. This technical solution improves signal quality by using a signal testing fixture and improved test points on the assembled printed circuit board for signal quality testing.

[0004] Another application, CN202110733195.0, provides an intelligent inspection system and method for double-layer circuit boards. This technical solution includes a transmission module, a controller, a database, a data acquisition module, a data analysis module, and an electrical testing module. This technical solution can inspect PCB boards on the PCB production line in real time. By using infrared scanning probes and cameras in combination, it can not only identify the size information of the PCB board, but also determine whether there are open circuits, short circuits, damage, copper surface scratches, and copper slag on the PCB board based on image recognition technology. This effectively improves the inspection accuracy and efficiency of PCB board surface quality and realizes automated inspection of PCB board surface defects.

[0005] However, the above-mentioned technical solutions are not sensitive enough to minor faults such as short circuits, open circuits, or component parameter deviations, resulting in poor intelligent fault diagnosis and location capabilities. It is difficult to accurately detect these potential problems, which can easily lead to missed detections. This allows faulty circuit boards to enter subsequent production stages or the market, affecting product quality and reliability. Summary of the Invention

[0006] In view of the problems existing in the field of electronic device testing technology, the present invention is proposed.

[0007] Therefore, one of the objectives of this invention is to provide a method for locating functional defects in circuit boards based on dynamic signal feature extraction. This method establishes a normal signal benchmark through database comparison and combines real-time feature extraction and dynamic threshold analysis to achieve accurate location and verification of fault points. In this process, it not only relies on static parameter comparison but also ensures the reliability of fault judgment through dynamic analysis such as transient response.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a method for locating functional defects in circuit boards based on dynamic signal feature extraction, comprising the following steps: S10: Obtain normal signal data of key nodes on the circuit board, the key nodes including power input terminal, signal input terminal and signal output terminal; the normal signal data includes voltage signal and current signal; construct a database about the normal signal data; S20: Collect voltage and current signals from key nodes of the circuit board, analyze the variation patterns of the voltage and current signals, and compare the variation patterns with the database; S30: Based on the comparison results, the voltage and current signals of the collected key nodes are marked with lines, including marking the power input terminal to the signal input terminal as line I and the signal input terminal to the signal output terminal as line II, and extracting key feature parameters from line I and line II. The key feature parameters include the effective value of the voltage and the peak value of the current. S40: Divide the signal points for collecting voltage and current signals in the line I and line II; obtain the minimum effective value and minimum current peak value among the effective value of the voltage and the peak value of the current, and obtain the signal points corresponding to the minimum effective value and minimum current peak value in the line I and line II; S50: Obtain the position corresponding to the signal point in line I and line II, and mark the position as a reference position; when the circuit board is sampled for voltage and current signals in the future, if the sampled voltage and current signals are lower than the minimum effective value and minimum current peak value of the reference position, the signal point corresponding to the sampled voltage and current signals is determined to be a fault point; otherwise, no determination is made.

[0009] In a preferred embodiment of the present invention, in step S20, the variation law of the voltage signal and the current signal is analyzed, including analysis by means of feature correlation analysis, wherein the feature correlation analysis includes voltage and current correlation analysis and power analysis; The voltage-current correlation analysis includes calculating the correlation coefficient between the voltage signal and the current signal. The power analysis includes calculating instantaneous power.

[0010] In a preferred embodiment of the present invention, the correlation coefficient between the voltage signal and the current signal is calculated according to the following formula: ; In the formula, Indicates voltage signal and current signal The correlation coefficient between them ranges from [-1, 1]; If the value is 1, it indicates a positive correlation, meaning that as the voltage signal increases, the current signal also increases. If the value is -1, it indicates a negative correlation, meaning that if one of the voltage and current signals increases, the other decreases. If the value is 0, then there is no linear correlation; Indicates voltage signal In the The value of each sampling point, Represents current signal In the The value of each sampling point, This represents the total number of sampling points. This represents the average value of the voltage signal. This represents the mean value of the current signal.

[0011] In a preferred embodiment of the present invention, the instantaneous power is calculated according to the following formula: ; In the formula, Indicates instantaneous power, which is the power of the circuit board during time. Power at that time This represents a voltage signal, indicating the circuit board's operation at time. Voltage at that time This represents the current signal, indicating the circuit board's operation in time. The current at that time.

[0012] In a preferred embodiment of the present invention, the method further includes calculating the phase difference between the voltage signal and the current signal, which is obtained according to the following formula: ; In the formula, Indicates voltage signal and current signal The phase difference between them The Fourier transform of the current signal represents the frequency of the current signal. The complex spectrum below, The Fourier transform of the voltage signal represents the voltage signal at a frequency of 1000 Hz. The complex spectrum below; The phase angle represents the complex number and is used to extract the phase component of the complex number; the steps are as follows: For voltage signals and current signal Perform a Fourier transform to obtain and ; calculate and ratio ; use The function extracts the phase angle of the complex ratio to obtain the phase difference. .

[0013] In a preferred embodiment of the present invention, the number of signal points for collecting voltage and current signals in the line I and line II is calculated; the average current and average voltage of the signal points in the line I and line II are calculated based on the calculated correlation coefficient and / or phase difference; the maximum current and maximum voltage corresponding to the average current and average voltage in the line I and line II are obtained; the signal point corresponding to the maximum current and maximum voltage is obtained; and the signal point is marked as a fault point.

[0014] In a preferred embodiment of the present invention, the fault point is verified, and the fault verification includes transient response analysis. The analysis method includes providing a specific event, which includes power-on, load change, and signal mutation. The transient response at the occurrence of the specific event is obtained, and the changes in voltage and current signals before and after the occurrence of the specific event are analyzed based on the transient response. The changes include overshoot of the amplitude of the voltage and current signals, and a safety threshold for overshoot of the amplitude of the voltage and current signals is preset. The changes before and after the occurrence of the specific event include overshoot within 1 minute before the occurrence of the specific event and within 1 minute after the occurrence of the specific event.

[0015] In a preferred embodiment of the present invention, the changes in voltage and current signals before and after the specific event are analyzed based on the transient response, and the analysis steps are as follows: Before and after the occurrence of the specific event shown, the voltage and current signals of the fault point are collected synchronously; The acquired voltage and current signals are plotted on a time axis to obtain the transient response of the voltage and current signals; In the transient response, key points of the voltage and current signals are marked, including peak values, valley values, and zero-crossing points, and the corresponding timestamps and amplitudes are recorded. Calculate overshoot based on the marked key points; If the overshoot exceeds the safety threshold, the signal point is marked as a fault point; otherwise, the mark is removed. Overshoot is calculated using the following formula: ; In the formula, Indicates overshoot of the current signal. This indicates the maximum value of the current signal within the stated amplitude range. This represents the final steady-state value of the current signal within the stated amplitude. ; In the formula, Indicates overshoot of the voltage signal. This indicates the maximum value of the voltage signal within the stated amplitude range. This represents the final steady-state value of the voltage signal within the stated amplitude.

[0016] A computer terminal includes a processor, an input interface, an output interface, and a memory, wherein the processor, input interface, output interface, and memory are interconnected, wherein the memory is used to store a computer program, the computer program including program instructions, and the processor is configured to invoke the program instructions to execute the method described above.

[0017] A computer-readable storage medium storing a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described above.

[0018] Beneficial effects: 1. This invention locates fault points in line I (from power input terminal to signal input terminal) and line II (from signal input terminal to signal output terminal) by using line marking and feature parameter extraction, thereby improving the efficiency and accuracy of fault diagnosis. 2. This invention not only analyzes the basic changing patterns of voltage and current signals, but also uses feature correlation analysis (such as voltage and current correlation analysis and power analysis) to gain a deeper understanding of signal characteristics. By calculating the correlation coefficient and instantaneous power between voltage and current, the working status of the circuit board can be evaluated more comprehensively, thereby more accurately identifying potential functional defects. 3. This invention introduces quantitative indicators, such as the effective value of voltage, peak current, phase difference, etc., as well as the average current and average voltage calculation based on these indicators, providing objective and quantifiable standards for fault judgment. This method reduces the subjectivity of human judgment and improves the accuracy and consistency of fault diagnosis. 4. By performing transient response analysis on the fault point, especially when specific events such as power-on, load changes, and signal abrupt changes occur, the transient changes of voltage and current signals are obtained. Based on these changes, overshoot phenomena are analyzed, and a safety threshold is preset to further verify the accuracy of the fault point and enhance the reliability of fault diagnosis. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the process structure of an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0021] Because existing technologies are not sensitive enough to minor faults such as short circuits, open circuits, or component parameter deviations, their ability to intelligently diagnose and locate faults is weak. This makes it difficult to accurately detect these potential problems, which can easily lead to missed detections. As a result, faulty circuit boards can flow into subsequent production stages or the market, affecting product quality and reliability.

[0022] Based on this, the present invention proposes a circuit board functional defect localization method based on dynamic signal feature extraction. It establishes a normal signal benchmark by comparing with a database, and combines real-time feature extraction and dynamic threshold analysis to achieve accurate location and verification of the fault point. This method not only relies on static parameter comparison, but also ensures the reliability of fault judgment through dynamic analysis such as transient response.

[0023] The present solution will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0024] Reference Figures 1 to 2 This is one embodiment of the present invention, which provides a method for locating functional defects in circuit boards based on dynamic signal feature extraction, including the following steps: S10: Obtain normal signal data for key nodes on the circuit board, including power input, signal input, and signal output terminals; normal signal data includes voltage and current signals; construct a database of normal signal data. In this embodiment, it should be noted that the normal signal data of the key nodes of the circuit board can be obtained from the manufacturer. Voltage signals are acquired using a high-precision voltage sensor. The sampling frequency of the sensor can be adjusted according to the operating frequency of the circuit board and the signal variation characteristics to ensure accurate capture of the voltage and its transient changes. Current signals are acquired at key nodes using current transformers or Hall effect sensors. S20: Collect voltage and current signals from key nodes of the circuit board, analyze the variation patterns of the voltage and current signals, and compare the variation patterns with the database; S30: Based on the comparison results, the voltage and current signals of the collected key nodes are marked with lines, including marking the power input terminal to the signal input terminal as line I and the signal input terminal to the signal output terminal as line II. Key feature parameters are extracted from line I and line II. Key feature parameters include the effective value of voltage and the peak value of current. S40: Divide the signal points for collecting voltage and current signals in Line I and Line II; obtain the minimum effective value and minimum current peak value among the effective value of voltage and the peak value of current, and obtain the signal points corresponding to the minimum effective value and minimum current peak value in Line I and Line II; In this embodiment, in reality, a small peak current will lead to insufficient performance of components on the circuit board, such as difficulty in starting the motor, slow response of the signal amplifier, and extended charging time of the capacitor. At the same time, the overall function of the circuit is limited, the transient response speed decreases, and the dynamic load adaptability deteriorates. Furthermore, integrated circuits (ICs) and other electronic components have specified minimum operating voltage ranges. If the effective voltage value is too low, below the minimum operating voltage of the component, the component will not be able to start or work properly. For example, if a chip with a rated operating voltage of 3.3V has an actual effective voltage of only 2.5V, the internal logic circuits of the chip may not be able to switch correctly, instructions may not be executed, and the chip may ultimately fail to work properly. S50: Obtain the position corresponding to the signal point in Line I and Line II, and mark the position as the reference position; when the circuit board is sampled for voltage and current signals in the future, if the sampled voltage and current signals are lower than the minimum effective value and minimum current peak value of the reference position, the signal point corresponding to the sampled voltage and current signals is determined to be a fault point; otherwise, no determination is made. In summary, by collecting voltage and current signals from key nodes (power input, signal input, and signal output) of the circuit board and comparing them with a pre-built normal signal database, the functional status of the circuit board can be determined. The selection of key nodes is based on the signal transmission path and functional importance, while the normal signal database provides a benchmark for subsequent comparisons. By collecting signals from multiple key nodes, the working status of the circuit board can be comprehensively monitored, avoiding potential problems that may be missed by single signal detection. Furthermore, with a database of normal signals as a reference, abnormal signals can be identified more accurately, improving the accuracy and reliability of detection. In S20, the variation patterns of voltage and current signals are analyzed, including analysis using feature correlation analysis, which includes voltage-current correlation analysis and power analysis. Voltage-current correlation analysis includes calculating the correlation coefficient between voltage and current signals. Power analysis includes calculating instantaneous power; In this embodiment, correlation analysis can reveal the dependence between voltage and current, which helps to understand the working principle of the circuit and potential failure modes. Power analysis can quantify the energy conversion efficiency of a circuit, providing an important reference for circuit design optimization and fault diagnosis.

[0025] The correlation coefficient between the voltage signal and the current signal is calculated using the following formula: ; In the formula, Indicates voltage signal and current signal The correlation coefficient between them ranges from [-1, 1]; If the value is 1, it indicates a positive correlation, meaning that as the voltage signal increases, the current signal also increases. If the value is -1, it indicates a negative correlation, meaning that if one of the voltage and current signals increases, the other decreases. If the value is 0, then there is no linear correlation; Indicates voltage signal In the The value of each sampling point, Represents current signal In the The value of each sampling point, This represents the total number of sampling points. This represents the average value of the voltage signal. This represents the mean value of the current signal; In this embodiment, the formula quantifies the degree of linear correlation between two signals by calculating the ratio of the product of their covariance and their respective standard deviations. The correlation coefficient ranges from [-1, 1], representing different linear correlation situations. This provides a quantitative indicator to evaluate the relationship between voltage and current, making the evaluation of this relationship more objective and accurate. Through this quantitative evaluation, the operating state of the circuit can be judged more accurately, providing strong support for circuit fault diagnosis and optimization design, and helping to discover potential circuit problems, thereby improving the reliability and performance of the circuit.

[0026] Instantaneous power is calculated using the following formula: ; In the formula, Indicates instantaneous power, which is the power of the circuit board during time. Power at that time This represents a voltage signal, indicating the circuit board's operation at time. Voltage at that time This represents the current signal, indicating the circuit board's operation in time. Current at that time; In this embodiment, the instantaneous power of the circuit board at that moment is calculated by multiplying the values ​​of the voltage signal and the current signal at each sampling point. The instantaneous power reflects the energy conversion and consumption of the circuit in a short period of time. It can provide precise energy consumption data of a circuit at different points in time, which helps to evaluate the dynamic performance and energy efficiency of the circuit. In this way, we can more accurately understand the energy utilization of the circuit under different operating conditions, thereby enabling real-time monitoring and optimization of circuit performance, as well as early detection of problems that may lead to a decrease in energy conversion efficiency, and thus improving the overall efficiency and reliability of the circuit.

[0027] It also includes calculating the phase difference between the voltage and current signals, which is obtained using the following formula: ; In the formula, Indicates voltage signal and current signal The phase difference between them The Fourier transform of the current signal represents the frequency of the current signal. The complex spectrum below, The Fourier transform of the voltage signal represents the voltage signal at a frequency of 1000 Hz. The complex spectrum below; The phase angle of a complex number is used to extract the phase component of the complex number. The steps are as follows: For voltage signals and current signal Perform a Fourier transform to obtain and ; calculate and ratio ; use The function extracts the phase angle of the complex ratio to obtain the phase difference. ; In this embodiment, Fourier transform is performed on the voltage signal and the current signal to obtain their spectra. The phase difference between the two signals is determined by calculating the phase angle of the spectrum ratio. The phase difference reflects the relative lag or lead relationship between voltage and current in time and is an important parameter for circuit characteristic analysis. This allows for a more comprehensive and in-depth analysis of circuit characteristics. Phase difference is one of the key parameters for understanding circuit behavior, especially in AC circuits, where it reflects the inductive or capacitive characteristics of the circuit. By accurately measuring and analyzing phase difference, we can better evaluate the performance of the circuit and detect phase anomalies that may lead to a decline in circuit performance or failure in advance, thereby improving the stability and reliability of the circuit and providing an important basis for circuit design, debugging and maintenance.

[0028] Calculate the number of signal points for collecting voltage and current signals in Line I and Line II. Based on the calculated correlation coefficient and / or phase difference, calculate the average current and average voltage of the signal points in Line I and Line II. Obtain the maximum current and maximum voltage in Line I and Line II that are lower than the average current and average voltage. Obtain the signal points that correspond to the maximum current and maximum voltage and mark the signal points as fault points. In this embodiment, in line I and line II, based on the number of signal points, combined with the average current and average voltage calculated by the correlation coefficient and phase difference, the signal points corresponding to the maximum current and maximum voltage below the average value are found and marked as fault points. This method identifies abnormal points based on the statistical characteristics of the signal. This statistical method can effectively identify abnormal fluctuations in signals, thereby quickly locating potential fault points. By marking fault points, maintenance personnel can find the problem more quickly, improve maintenance efficiency, reduce maintenance time and costs, and enhance the reliability and availability of circuit boards.

[0029] Fault verification is performed on the fault point, including transient response analysis. The analysis method includes providing a specific event, such as power-on, load change, and signal abrupt change; acquiring the transient response when the specific event occurs; analyzing the changes in voltage and current signals before and after the specific event based on the transient response, including overshoot of the voltage and current signal amplitudes, and setting a safety threshold for overshoot of the voltage and current signal amplitudes; the changes before and after the specific event include overshoot within 1 minute before and 1 minute after the specific event. In this embodiment, the changes in voltage and current signals before and after a specific event (such as power-on, load change, signal change, etc.) are analyzed. The main purpose is to observe the transient behavior of these signals when the event is triggered. These changes can help determine the stability and response speed of the circuit board. Before and after a specific event (such as power-on, load change, signal change) occurs, the voltage and current signals at the fault point are collected synchronously, the transient response curve is plotted, key points (peak, valley, zero crossover point) are marked, overshoot is calculated, and compared with the preset safety threshold to verify the fault point. Transient response analysis can capture the instantaneous changes in the signal when a specific event is triggered. These changes are often the direct manifestation of circuit faults. Transient response analysis can capture the instantaneous changes in a signal when a specific event is triggered. These changes are often a direct manifestation of circuit faults. By comparing them with preset safety thresholds, the fault point can be verified more accurately, avoiding misjudgment. Transient response analysis can evaluate the performance of a circuit under dynamic conditions, help optimize circuit design, improve its stability and reliability under various operating conditions, and ensure the performance of the circuit in practical applications.

[0030] Based on transient response analysis, the changes in voltage and current signals before and after a specific event are analyzed. The steps of the analysis are as follows: Before and after the occurrence of the specific event shown, the voltage and current signals at the fault point are collected synchronously. The acquired voltage and current signals are plotted on the time axis to obtain the transient response of the voltage and current signals; Mark the key points of voltage and current signals in the transient response, including peak values, valley values ​​and zero crossing points, and record the corresponding timestamps and amplitudes. Calculate overshoot based on the marked key points; If the overshoot exceeds the safety threshold, the signal point is marked as a fault point; otherwise, the mark is removed. Overshoot is calculated using the following formula: ; In the formula, Indicates overshoot of the current signal. This represents the maximum value of the current signal within its amplitude range. This represents the final steady-state value of the current signal within its amplitude range; ; In the formula, Indicates overshoot of the voltage signal. This represents the maximum value of the voltage signal within its amplitude range. This represents the final steady-state value of the voltage signal within its amplitude range; It should be noted that by quantifying the degree of overshoot, the transient change amplitude of the signal when a specific event occurs can be evaluated more intuitively. Overshoot exceeding the safety threshold may indicate potential problems in the circuit, such as power quality issues or impacts caused by load switching. This quantitative analysis helps to promptly detect and address overshoot phenomena that may lead to circuit damage or performance degradation, thereby improving the reliability and durability of the circuit system.

[0031] A computer terminal includes a processor, an input interface, an output interface, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the method described above.

[0032] A computer-readable storage medium storing a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described above.

[0033] In summary, by establishing a normal signal benchmark through database comparison and combining real-time feature extraction and dynamic threshold analysis, the fault point can be accurately located and verified. This invention not only relies on static parameter comparison, but also ensures the reliability of fault judgment through dynamic analysis such as transient response.

[0034] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for locating functional defects in circuit boards based on dynamic signal feature extraction, characterized in that, Includes the following steps: S10: Acquire normal signal data of key nodes on the circuit board, wherein the key nodes include power input terminal, signal input terminal and signal output terminal; the normal signal data includes voltage signal and current signal; Construct a database of the normal signal data; S20: Collect voltage and current signals from key nodes of the circuit board, analyze the variation patterns of the voltage and current signals, and compare the variation patterns with the database; S30: Based on the comparison results, the voltage and current signals of the collected key nodes are marked with lines, including marking the power input terminal to the signal input terminal as line I and the signal input terminal to the signal output terminal as line II, and extracting key feature parameters from line I and line II. The key feature parameters include the effective value of the voltage and the peak value of the current. S40: Divide the signal points for collecting voltage and current signals in Line I and Line II; Obtain the minimum effective value and minimum current peak value from the effective value of the voltage and the peak value of the current, and obtain the signal points corresponding to the minimum effective value and minimum current peak value in line I and line II; S50: Obtain the position corresponding to the signal point in the line I and line II, and mark the position as the reference position; when the circuit board is sampled for voltage and current signals in the future, if the sampled voltage and current signals are lower than the minimum effective value and minimum current peak value of the reference position, the signal point corresponding to the sampled voltage and current signals is determined to be a fault point. Conversely, no judgment is made.

2. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 1, characterized in that, In S20, the variation patterns of the voltage and current signals are analyzed, including analysis by means of feature correlation analysis, which includes voltage-current correlation analysis and power analysis. The voltage-current correlation analysis includes calculating the correlation coefficient between the voltage signal and the current signal. The power analysis includes calculating instantaneous power.

3. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 2, characterized in that, The correlation coefficient between the voltage signal and the current signal is calculated using the following formula: ； In the formula, Indicates voltage signal and current signal The correlation coefficient between them ranges from [-1, 1]; If the value is 1, it indicates a positive correlation, meaning that as the voltage signal increases, the current signal also increases. If the value is -1, it indicates a negative correlation, meaning that if one of the voltage and current signals increases, the other decreases. If the value is 0, then there is no linear correlation; Indicates voltage signal In the The value of each sampling point, Represents current signal In the The value of each sampling point, This represents the total number of sampling points. This represents the average value of the voltage signal. This represents the mean value of the current signal.

4. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 2, characterized in that, Instantaneous power is calculated using the following formula: ； In the formula, Indicates instantaneous power, which is the power of the circuit board during time. Power at that time This represents a voltage signal, indicating the circuit board's operation at time. Voltage at that time This represents the current signal, indicating the circuit board's operation in time. The current at that time.

5. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 4, characterized in that, It also includes calculating the phase difference between the voltage and current signals, which is obtained using the following formula: ； In the formula, Indicates voltage signal and current signal The phase difference between them The Fourier transform of the current signal represents the frequency of the current signal. The complex spectrum below, The Fourier transform of the voltage signal represents the voltage signal at a frequency of 1000 Hz. The complex spectrum below; The phase angle represents the complex number and is used to extract the phase component of the complex number; the steps are as follows: For voltage signals and current signal Perform a Fourier transform to obtain and ; calculate and ratio ; use The function extracts the phase angle of the complex ratio to obtain the phase difference. .

6. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 5, characterized in that, Calculate the number of signal points for collecting voltage and current signals in Line I and Line II. Based on the calculated correlation coefficient and / or phase difference, calculate the average current and average voltage of the signal points in Line I and Line II. Obtain the maximum current and maximum voltage in Line I and Line II that are lower than the average current and average voltage. Obtain the signal point corresponding to the maximum current and maximum voltage and mark the signal point as a fault point.

7. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 6, characterized in that, The fault point is verified, including transient response analysis. The analysis method includes providing a specific event, such as power-on, load change, and signal abrupt change; acquiring the transient response at the occurrence of the specific event; analyzing the changes in voltage and current signals before and after the occurrence of the specific event based on the transient response; the changes include overshoot of the amplitude of the voltage and current signals; and setting a safety threshold for overshoot of the amplitude of the voltage and current signals; the changes before and after the occurrence of the specific event include overshoot within 1 minute before and 1 minute after the occurrence of the specific event.

8. The circuit board functional defect localization method based on dynamic signal feature extraction as described in claim 7, characterized in that, Based on the transient response analysis, the changes in voltage and current signals before and after the specific event occur are analyzed. The steps of the analysis are as follows: Before and after the occurrence of the specific event shown, the voltage and current signals of the fault point are collected synchronously; The acquired voltage and current signals are plotted on a time axis to obtain the transient response of the voltage and current signals; In the transient response, key points of the voltage and current signals are marked, including peak values, valley values, and zero-crossing points, and the corresponding timestamps and amplitudes are recorded. Calculate overshoot based on the marked key points; If the overshoot exceeds the safety threshold, the signal point is marked as a fault point; otherwise, the mark is removed. Overshoot is calculated using the following formula: ； In the formula, Indicates overshoot of the current signal. This indicates the maximum value of the current signal within the stated amplitude range. This represents the final steady-state value of the current signal within the stated amplitude. ； In the formula, Indicates overshoot of the voltage signal. This indicates the maximum value of the voltage signal within the stated amplitude range. This represents the final steady-state value of the voltage signal within the stated amplitude.

9. A computer terminal, characterized in that, The system includes a processor, an input interface, an output interface, and a memory, which are interconnected. The memory is used to store a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the method as described in any one of claims 1 to 8.

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