Cable terminal crimping quality detection method, device and equipment and storage medium

Abstract

The invention discloses a cable terminal crimping quality detection method, device and equipment and a storage medium, and relates to the technical field of cable testing, and the method comprises the steps: exciting a cable terminal through a current pin in the crimping process of the cable terminal, collecting the voltage of the cable terminal through a voltage pin, and obtaining a real-time voltage signal; and evaluating the crimping quality of the cable terminal based on the resistance change condition of the real-time resistance value in the crimping process. According to the invention, the detection behavior and the crimping process are carried out synchronously, and the real-time monitoring of the dynamic change of the resistance in the crimping process is realized, so that the method can be applied to the one-by-one full detection of a production line, and the measurement mode of separating current excitation and voltage collection is adopted. A system error caused by lead resistance introduced by a common lead of current excitation and voltage acquisition is avoided, and real-time performance, non-destructive performance and high precision are effectively considered when the crimping quality of the cable terminal is evaluated.

Description

Technical Field

[0001] This application relates to the field of cable testing technology, and in particular to a method, apparatus, equipment and storage medium for testing the quality of cable terminal crimping. Background Technology

[0002] Copper-aluminum composite cables, with their advantages of lightweight and high conductivity, have been widely used in fields with high reliability requirements, such as power transmission, new energy vehicles, and aerospace. However, the connection reliability and safety of copper-aluminum composite cables are highly dependent on the quality of terminal crimping. Current mainstream methods for evaluating crimping quality mainly include tensile testing after crimping and static resistance measurements using methods such as the Wheatstone bridge or a two-wire ohmmeter.

[0003] Tensile testing requires breaking the connection structure to obtain strength data, so it can only be performed after the crimping process is completely finished. This makes it impossible to capture and report dynamically occurring defects in real time during the crimping process. Furthermore, methods like tensile testing are destructive, and the tested samples are usually unusable. This means these methods can only be used for sampling inspection and cannot be used for full inspection of every product on the production line, posing a risk of missed inspections. Static resistance measurements such as the bridge method require a stable contact state. Although they have high accuracy, their balanced detection principle results in a slow response speed, which cannot keep up with the millisecond-level dynamic changes during the crimping process and cannot adapt to the dynamic environment accompanied by mechanical vibration and material deformation during the crimping process. When using the two-wire ohmmeter method, the current and voltage share the same pair of wires, and the resistance of the wires themselves is directly superimposed on the measured contact resistance value, causing significant errors. Summary of the Invention

[0004] The main objective of this application is to provide a method, apparatus, equipment, and storage medium for testing the quality of cable terminal crimping, aiming to solve the technical problem that current evaluation schemes for cable terminal crimping quality cannot simultaneously achieve real-time performance, non-destructive testing, and high precision.

[0005] To achieve the above objectives, this application proposes a method for inspecting the crimping quality of cable terminals, the method comprising: During the crimping process of the cable terminals, the cable terminals are excited by a current needle, and the voltage on the cable terminals is collected by a voltage needle to obtain a real-time voltage signal; The real-time resistance value of the cable terminal is determined based on the real-time voltage signal; The crimping quality of the cable terminal is evaluated based on the resistance change of the real-time resistance value during the crimping process.

[0006] In one embodiment, the current needle includes a first current needle and a second current needle. A standard resistor is also connected in series in the excitation circuit formed by the first current needle, the cable terminal, and the second current needle. The step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal includes: Monitor the reference voltage across the standard resistor and determine the detection resistance value of the cable terminal based on the detection voltage value corresponding to the real-time voltage signal; The detected resistance value is calibrated based on the reference voltage value and the reference resistance value of the standard resistor to obtain the real-time resistance value of the cable terminal.

[0007] In one embodiment, before the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal, the method further includes: The real-time voltage signal is amplified to obtain an amplified voltage signal; The amplified voltage signal is filtered to obtain a target voltage signal, which is then used as the real-time voltage signal to perform the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal.

[0008] In one embodiment, the step of filtering the amplified voltage signal to obtain the target voltage signal includes: The real-time voltage signal is sequentially subjected to low-pass filtering and notch filtering to obtain the target voltage signal, wherein the sampling frequency corresponding to the real-time voltage signal is the first sampling frequency; or The real-time voltage signal is subjected to low-pass filtering and wavelet transform in sequence to obtain a multi-scale decomposed signal. The high-frequency part of the multi-scale decomposed signal is then denoised to obtain the target voltage signal. The sampling frequency corresponding to the real-time voltage signal is a second sampling frequency, which is higher than the second sampling frequency.

[0009] In one embodiment, the step of evaluating the crimping quality of the cable terminal based on the resistance change of the real-time resistance value during the crimping process includes: A resistance change curve is constructed based on the real-time resistance value during the crimping process, and the crimping quality of the cable terminal is evaluated based on the resistance change curve; or Based on the resistance change of the real-time resistance value during the crimping process, the resistance change parameter is determined, and the resistance change parameter is input into the pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0010] In one embodiment, the step of evaluating the crimping quality of the cable terminal based on the resistance change curve includes: The shape of the resistance change curve is compared with multiple preset reference shapes to determine the target shape that matches the curve shape among the reference shapes. Obtain the calibration crimping quality corresponding to the target shape, and use the calibration crimping quality as the crimping quality of the cable terminal.

[0011] In one embodiment, the step of determining the resistance change parameter based on the resistance change of the real-time resistance value during the crimping process, and inputting the resistance change parameter into a pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model includes: The average resistance value, standard deviation of resistance fluctuation, minimum descent slope, resistance stabilization time and kurtosis index are determined based on the resistance change of the real-time resistance value during the crimping process. The average resistance value, the standard deviation of resistance fluctuation, the minimum descent slope, the resistance stabilization time, and the kurtosis index are input into a pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0012] Furthermore, to achieve the above objectives, this application also proposes a cable terminal crimping quality testing device, which includes: The crimping acquisition module is used to excite the cable terminal through a current needle and acquire the voltage on the cable terminal through a voltage needle during the crimping process to obtain a real-time voltage signal. A resistance monitoring module is used to determine the real-time resistance value of the cable terminal based on the real-time voltage signal; The quality assessment module is used to evaluate the crimping quality of the cable terminals based on the resistance change of the real-time resistance value during the crimping process.

[0013] In addition, to achieve the above objectives, this application also proposes an electronic device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the cable terminal crimping quality detection method as described above.

[0014] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the cable terminal crimping quality detection method described above.

[0015] One or more technical solutions proposed in this application have at least the following technical effects: The technical solution of this application, while crimping the cable terminals, excites the cable terminals with a current needle and collects real-time voltage signals on a voltage needle, thereby directly obtaining the electrical response during the dynamic process of crimping. Next, the real-time resistance value is calculated based on the real-time voltage signal, and the crimping quality is evaluated based on the change of the real-time resistance value throughout the crimping process. Since the detection is performed synchronously with the crimping process, real-time monitoring of the dynamic changes in resistance during crimping is achieved, eliminating the response lag problem caused by traditional static measurement methods that must be performed after crimping, thus meeting real-time requirements. Secondly, the entire detection process is completed solely through electrical signal excitation and acquisition, causing no physical damage to the cable terminal structure. This allows the method to be applied to piece-by-piece inspection on the production line, avoiding the risk of missed inspections caused by sampling inspections, and achieving non-destructive testing. Finally, by adopting a measurement method that separates current excitation and voltage acquisition, the systematic error caused by the wire resistance introduced by the shared wires for current excitation and voltage acquisition is avoided from the measurement principle. Combined with real-time processing of dynamic voltage signals, resistance changes can be accurately captured, thereby directly identifying resistance anomalies caused by defects such as poor contact and micro-cracks during the crimping process, achieving high-precision detection. Therefore, when evaluating the crimping quality of cable terminals, real-time performance, non-destructive testing, and high precision are effectively balanced. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating an embodiment of the cable terminal crimping quality testing method of this application. Figure 2 A schematic diagram of the resistance change curve of the cable terminal crimping quality detection method provided in Embodiment 1 of this application; Figure 3 This is a flowchart illustrating Embodiment 2 of the cable terminal crimping quality inspection method of this application; Figure 4 This is a schematic diagram of the filtering process for the cable terminal crimping quality detection method provided in Embodiment 2 of this application; Figure 5 This is a schematic diagram of the system framework for the cable terminal crimping quality inspection method provided in Embodiment 2 of this application; Figure 6This is a schematic diagram of the crimping machine used in the cable terminal crimping quality inspection method provided in Embodiment 2 of this application; Figure 7 This is a schematic diagram of the module structure of the cable terminal crimping quality inspection device according to an embodiment of this application; Figure 8 This is a schematic diagram of the equipment structure of the hardware operating environment involved in the cable terminal crimping quality detection method in this application embodiment.

[0019] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0021] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0022] The main solution of this application embodiment is: during the crimping process of the cable terminal, the cable terminal is excited by a current needle and the voltage on the cable terminal is collected by a voltage needle to obtain a real-time voltage signal; the real-time resistance value of the cable terminal is determined according to the real-time voltage signal; and the crimping quality of the cable terminal is evaluated based on the resistance change of the real-time resistance value during the crimping process.

[0023] Because tensile testing requires breaking the connection structure to obtain strength data, it can only be performed after the crimping process is completely finished. This makes it impossible to capture and report dynamically occurring defects in real time during crimping. Furthermore, methods like tensile testing are destructive, and the tested samples are usually unusable. This limits these methods to sampling inspection only, preventing full inspection of every product on the production line and posing a risk of missed inspections. Static resistance measurements such as the bridge method require a stable contact state. While they offer high accuracy, their balanced detection principle results in a slow response, unable to keep up with the millisecond-level dynamic changes during crimping, and unable to adapt to the dynamic environment accompanied by mechanical vibration and material deformation during crimping. When using the two-wire ohmmeter method, current and voltage share the same pair of wires, and the resistance of the wires themselves is directly superimposed on the measured contact resistance value, causing significant errors.

[0024] This application provides a solution that directly obtains the electrical response during the crimping dynamic process by exciting the cable terminal with a current needle and acquiring a real-time voltage signal on a voltage needle. Next, the real-time resistance value is calculated based on the real-time voltage signal, and the crimping quality is evaluated based on the change of the real-time resistance value throughout the crimping process. Since the detection is performed synchronously with the crimping process, real-time monitoring of the dynamic changes in resistance during crimping is achieved, eliminating the response lag problem caused by traditional static measurement methods that must be performed after crimping, thus meeting real-time requirements. Secondly, the entire detection process is completed solely through electrical signal excitation and acquisition, causing no physical damage to the cable terminal structure. This allows the method to be applied to piece-by-piece inspection on the production line, avoiding the risk of missed inspections caused by sampling inspections, and achieving non-destructive testing. Finally, by adopting a measurement method that separates current excitation and voltage acquisition, the systematic error caused by the wire resistance introduced by the shared wires for current excitation and voltage acquisition is avoided from the measurement principle. Combined with real-time processing of dynamic voltage signals, resistance changes can be accurately captured, thereby directly identifying resistance anomalies caused by defects such as poor contact and micro-cracks during the crimping process, achieving high-precision detection. Therefore, when evaluating the crimping quality of cable terminals, real-time performance, non-destructive testing, and high precision are effectively balanced.

[0025] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or an electronic device capable of performing the above functions. The following description uses an electronic device as an example to illustrate this embodiment and the subsequent embodiments.

[0026] Based on this, the embodiments of this application provide a method for detecting the crimping quality of cable terminals, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the cable terminal crimping quality inspection method of this application.

[0027] In this embodiment, the cable terminal crimping quality detection method includes steps S10~S40: Step S10: During the crimping process of the cable terminal, the cable terminal is excited by a current needle and the voltage on the cable terminal is collected by a voltage needle to obtain a real-time voltage signal. It should be noted that the current probes are a pair of conductive probes used to inject excitation current into the cable terminals during the crimping process. Specifically, they can be implemented as two independent current probes, each contacting one end of the cable terminal, forming a closed excitation current loop together with an external constant current source. This pair of current probes provides a known and stable excitation current to the cable terminals under test simultaneously with the crimping process, which is a prerequisite for subsequent dynamic resistance measurement.

[0028] Voltage needles are a pair of conductive probes specifically used during the crimping process to accurately acquire the voltage drop across the cable terminals. They can be implemented as two independent voltage needles, physically separated from the current needles, for example, spaced 2 ± 0.1 mm apart. These voltage needles can directly and purely acquire the minute voltage signal generated when the excitation current flows through the cable terminal—that is, the real-time voltage signal. Because they do not carry the excitation current, they eliminate the interference of the measuring conductor's own resistance on the results. The real-time voltage signal refers to the sequence of raw voltage data continuously acquired by the pair of voltage needles during the synchronous time of the cable terminal crimping process. This signal directly reflects, at the millisecond level, the instantaneous voltage fluctuations across the terminals caused by the plastic deformation of the metal material and microscopic changes at the contact interface during the dynamic process of crimping. This signal is typically at the μV (microvolt) level and is the fundamental data for subsequent signal processing and resistance calculations.

[0029] Step S20: Determine the real-time resistance value of the cable terminal based on the real-time voltage signal; It should be noted that the real-time resistance value is a dynamic contact resistance of the cable terminal that varies over time, calculated in real-time based on the real-time voltage signal and combined with the known value of the excitation current provided by a pair of current needles. This value sequence characterizes the instantaneous conductivity state of the metal contact interface inside the cable terminal at each moment during the crimping process, and its changes are directly related to the evolution of the crimping quality.

[0030] Step S30: Evaluate the crimping quality of the cable terminal based on the resistance change of the real-time resistance value during the crimping process.

[0031] It should be noted that the resistance change status refers to the dynamic behavior and evolution of the real-time resistance value throughout the entire crimping process. This status encompasses the overall trend of resistance change over time (such as continuous decrease, plateau fluctuation, or abnormal rebound), the rate of change, the amplitude of fluctuation, and the time required to reach relative stability, among other comprehensive time-domain characteristics. By analyzing the resistance change status (such as the smooth decrease curve of a qualified crimp, the large fluctuation curve of a poor connection, and the curve of initial decrease followed by increase for potential cracks), different crimping quality states can be distinguished.

[0032] It is understandable that this embodiment employs a technique of simultaneously performing electrical excitation and signal acquisition during the crimping process. Specifically, while crimping the cable terminals, a current needle excites the cable terminals to establish a known current excitation circuit, and a voltage needle simultaneously acquires the voltage on the cable terminals, thereby obtaining a real-time voltage signal. The real-time resistance value is then calculated based on this signal, and the quality is ultimately evaluated based on the resistance change throughout the crimping process. This technical solution avoids three key problems in terms of principle and execution timing: First, by embedding the detection action into the crimping process, it avoids the "crimp first, test later" mode that must be performed only after crimping is completely finished, thus overcoming the inherent response lag problem of traditional static methods; second, the entire detection is completed only through non-contact or micro-contact electrical measurements, avoiding physical damage to the cable terminal structure, thus overcoming the problem that destructive detection methods cannot be used for full inspection; third, by adopting a measurement method that separates current excitation and voltage acquisition, it avoids introducing systematic errors due to wire resistance from the measurement principle, thus laying the foundation for achieving high-precision resistance measurement in dynamic environments. Therefore, the solution in this embodiment directly and effectively achieves the unity of the three technical effects of real-time monitoring, non-destructive full inspection, and high-precision detection.

[0033] For example, while the crimping machine begins crimping the cable terminals, a pair of current probes are respectively contacted at both ends of the terminal to inject a constant excitation current. Simultaneously, a pair of voltage probes are physically separated from the current probes and contacted at both ends of the terminal. The voltage drop generated by the excitation current is directly collected, thereby obtaining a real-time voltage signal updated in milliseconds. The excitation current originates from a constant current source, which can be a switching circuit such as LM2596, outputting a 1–2A DC current (preferably 1A, ripple <1%) to provide stable excitation for the measurement circuit. In addition, the current and voltage probes can be gold-plated to make their contact resistance <0.1 mΩ (milliohms) and embedded in the inner wall of the crimping mold. The current and voltage probes are separated by a gap of 2±0.1 mm, and the distance between the probe tip and the crimping area is ≤0.5 mm to ensure contact reliability. Subsequently, the signal processing unit calculates and outputs the dynamic contact resistance of the cable terminal, i.e., the real-time resistance value, based on the real-time voltage signal and the known excitation current value. Finally, the system continuously monitors the trend, fluctuation range and stabilization process of the real-time resistance value throughout the entire crimping cycle. By analyzing the resistance change, such as whether the resistance drops steadily to the predetermined range, or whether there are abnormal fluctuations or rebounds, the system directly determines whether the crimping quality is qualified.

[0034] This embodiment provides a method for detecting the crimping quality of cable terminals. By exciting the cable terminals with a current needle and collecting real-time voltage signals on a voltage needle, the electrical response during the crimping dynamic process can be directly obtained. Next, the real-time resistance value is calculated based on the real-time voltage signal, and the crimping quality is evaluated based on the change of the real-time resistance value throughout the crimping process. Since the detection is performed synchronously with the crimping process, real-time monitoring of the dynamic changes in resistance during crimping is achieved, eliminating the response lag problem caused by traditional static measurement methods that must be performed after crimping, thus meeting real-time requirements. Secondly, the entire detection process is completed solely through electrical signal excitation and acquisition, causing no physical damage to the cable terminal structure. This allows the method to be applied to piece-by-piece inspection on the production line, avoiding the risk of missed inspections caused by sampling inspections, and achieving non-destructive testing. Finally, by adopting a measurement method that separates current excitation and voltage acquisition, the systematic error caused by the wire resistance introduced by the shared wires for current excitation and voltage acquisition is avoided from the measurement principle. Combined with real-time processing of dynamic voltage signals, resistance changes can be accurately captured, thereby directly identifying resistance anomalies caused by defects such as poor contact and micro-cracks during the crimping process, achieving high-precision detection. Therefore, when evaluating the crimping quality of cable terminals, real-time performance, non-destructive testing, and high precision are effectively balanced.

[0035] In one feasible implementation, the current needle includes a first current needle and a second current needle. A standard resistor is also connected in series in the excitation circuit formed by the first current needle, the cable terminal, and the second current needle. Step S20 may include steps S21-S22: Step S21: Monitor the reference voltage value across the standard resistor and determine the detection resistance value of the cable terminal based on the detection voltage value corresponding to the real-time voltage signal; It should be noted that the standard resistor is a resistor element with a known, accurate, and stable resistance value (i.e., a reference resistance value), which is connected in series in the excitation circuit consisting of the first current probe, the cable terminal, and the second current probe. It is typically a high-precision, low-temperature-drift sampling resistor (e.g., accuracy class 0.01, resistance value 5mΩ), and its core function is to provide a relatively accurate proportional reference. By measuring the voltage across the standard resistor, the actual current value in the excitation circuit can be accurately deduced, or it can be directly used to perform proportional calculations with the resistance of the cable terminal under test, thereby achieving online calibration of the measurement system and eliminating systematic errors such as constant current source output drift and contact resistance variations.

[0036] The reference voltage value refers to the voltage drop across the standard resistor when the excitation current flows through it in series. Monitoring this voltage value is important because, since the resistance of the standard resistor is known and precise, according to Ohm's law, this reference voltage value is strictly linearly proportional to the magnitude of the excitation current. Therefore, this value provides a crucial benchmark for subsequent calibration of the resistance of the cable terminals under test.

[0037] The detected voltage value refers to the voltage value represented by the real-time voltage signal corresponding to both ends of the cable terminal, which is collected by the voltage needle. This value directly reflects the voltage drop generated when the excitation current flows through the cable terminal itself. This value is the direct input for calculating the resistance of the cable terminal, but its accuracy depends on the stability of the excitation current and the precision of the measurement system.

[0038] The detected resistance value refers to the cable terminal resistance value initially calculated using Ohm's law based on the detected voltage value and the nominal or estimated value of the current excitation current. Without calibration using a standard resistor, this value may contain errors introduced by factors such as the actual excitation current deviating from the nominal value and conductor voltage drop. Therefore, this detected resistance value is an intermediate calculation result to be calibrated and needs to be corrected using calibration coefficients derived from a standard resistor and reference voltage value to obtain an accurate real-time resistance value.

[0039] Step S22: Based on the reference voltage value and the reference resistance value of the standard resistor, the detection resistance value is calibrated to obtain the real-time resistance value of the cable terminal.

[0040] It is understandable that even with a separate current and voltage probe measurement method, the actual value of the excitation current may still deviate from the preset value due to fluctuations in the constant current source, contact point temperature rise, or long-term drift, resulting in a non-negligible systematic error in the real-time resistance value calculated based on the nominal current. To address this, this implementation connects a standard resistor with a known precise resistance value in series in the excitation circuit. During the crimping process, the reference voltage across the standard resistor is monitored simultaneously, and the detection voltage across the cable terminals is acquired. First, the uncalibrated detection resistance value is calculated based on the detection voltage value. Then, using the ratio of the actual current determined by the reference voltage value and the reference resistance value of the standard resistor, the detection resistance value is calibrated in real time. This avoids the systematic error problem in resistance measurement directly caused by the unknown or unstable actual value of the excitation current, achieving high-precision and high-stability measurement of micro-ohm-level dynamic resistance and ensuring the accuracy of the resistance data used for quality assessment.

[0041] For example, in the excitation circuit consisting of a first current needle, a cable terminal, and a second current needle connected in series, an additional standard resistor with a known and precise resistance is connected, such as a 5mΩ reference resistor with an accuracy of 0.01%. During each crimping process, the constant current source outputs an excitation current that flows through the complete circuit, simultaneously measuring the voltage across the standard resistor as a reference voltage value, and measuring the voltage across the cable terminal as a detection voltage value. The signal processing system first preliminarily calculates the detection resistance value R_test of the cable terminal based on the detection voltage value U_test and the nominal value of the excitation current. Then, using the reference voltage value U_ref and the known reference resistance value R_ref of the standard resistor, the detection resistance value R_test is calculated and calibrated in real time using the proportional relationship: R_test = (U_test / U_ref) * R_ref, ultimately obtaining the real-time resistance value of the cable terminal that accurately reflects the contact state.

[0042] In one feasible implementation, step S30 may include step A31: Step A31: Construct a resistance change curve based on the resistance change of the real-time resistance value during the crimping process, and evaluate the crimping quality of the cable terminal based on the resistance change curve.

[0043] It should be noted that the resistance change curve can be plotted as a continuous curve with the time of the crimping process on the horizontal axis and the real-time resistance value on the vertical axis. This curve is a visual graphical representation of the dynamic evolution of the real-time resistance value throughout the entire crimping process. Its shape (such as downward trend, fluctuation characteristics, stable plateau, rebound inflection point, etc.) directly reflects the complete physical process of plastic deformation of metal materials, formation and evolution of contact interface, and even the generation of potential defects during the crimping process. It is an intuitive basis for qualitative or semi-quantitative evaluation of crimping quality.

[0044] It is understandable that a single final resistance value or a transient value cannot fully characterize the complex dynamic contact behavior during crimping. Different types of defects (such as poor connections or microcracks) may exhibit unique but subtle differences in the dynamic evolution pattern of resistance, and these differences cannot be captured by static threshold judgment. To address this, this embodiment employs a technique of constructing a resistance change curve and performing an overall analysis of the curve's shape. The real-time resistance value, which changes over time, is fitted into a continuous curve, and the overall shape and trend of this curve (such as monotonically decreasing, fluctuating, or rebounding) are compared with preset typical reference shapes representing different quality states. This avoids the problem of being unable to distinguish defects with the same final value but vastly different processes when relying solely on a single resistance threshold for judgment—for example, stable contact versus potential cracks that initially improve but later deteriorate. This allows for a more comprehensive and reliable differentiation of different types of crimping quality states through process morphology identification, improving the depth and accuracy of detection.

[0045] In the specific implementation process, step A31 may include steps A311 to A312: Step A311: Compare the curve shape of the resistance change curve with multiple preset reference shapes to determine the target shape that matches the curve shape among the reference shapes. It should be noted that the curve morphology is the sum of the overall geometric shape and dynamic trend characteristics of the resistance change curve, including but not limited to visual and mathematical features such as the curve's monotonicity (e.g., continuous decline, rise, or stability), volatility (e.g., amplitude and frequency characteristics), inflection points (e.g., inflection points and extreme points), and the convergence mode to reach steady state. These features are a visual and graphical summary of the resistance change during the crimping process and form the basis for qualitative comparison and pattern recognition.

[0046] Reference patterns are pre-calibrated templates of typical curve patterns that are strongly correlated with specific crimping quality results (such as "qualified," "poor connection," or "potential for cracking"), based on experiments or historical data. Each reference pattern corresponds to a specific physical state; for example, a pattern that steadily decreases to a low resistance value represents a qualified crimping, a pattern with large and continuous fluctuations represents a poor connection, and a pattern that decreases first and then rebounds significantly indicates the possible presence of internal cracks. These reference patterns constitute a knowledge base or standard for evaluation and comparison.

[0047] The target profile refers to the specific reference profile with the highest degree of matching, determined by comparing and analyzing the curve shape of the resistance change curve to be evaluated with multiple reference profiles. The selection of this target profile means that the dynamic resistance behavior of the current crimping process is closest to the physical process represented by this reference profile, thus providing a direct classification basis for quality judgment.

[0048] Step A312: Obtain the calibration crimping quality corresponding to the target shape, and use the calibration crimping quality as the crimping quality of the cable terminal.

[0049] It should be noted that the calibrated crimping quality is a pre-assigned, explicit quality judgment for each reference shape. It is a label value corresponding one-to-one with each reference shape, such as "qualified," "unqualified (poor connection)," or "unqualified (potential for cracking)." Once the target shape is determined, the system directly outputs the calibrated crimping quality associated with that target shape as the final evaluation result of the current cable terminal crimping quality. This mechanism simplifies complex curve morphology analysis into a reliable classification output.

[0050] Understandably, directly evaluating continuous curves as a whole presents challenges due to strong subjectivity, difficulty in standardizing judgment criteria, and complexity in automation. Therefore, this implementation employs a pre-set reference shape library and shape matching comparison technique. Specifically, typical reference shapes representing different quality states are pre-established and stored. During testing, the measured curve shape is automatically compared with all reference shapes to identify the target shape with the highest matching degree. The calibrated crimping quality corresponding to this target shape is then directly output. This avoids the problems of inconsistent evaluation results, low efficiency, and susceptibility to subjective experience caused by relying on manual real-time curve interpretation or complex criteria. It achieves rapid, objective, and standardized automatic judgment of crimping quality, significantly improving the reliability and repeatability of the testing system.

[0051] For example, the system pre-stores several standardized reference resistance-time curves and their corresponding calibrated crimping quality in the database. For instance, a curve that steadily decreases to a low resistance value is calibrated as "qualified," while a curve that fluctuates significantly is calibrated as "loose connection." During testing, the system plots the resistance change curve of the current crimping process in real time and automatically extracts the key morphological features of the curve, such as the overall trend direction, fluctuation amplitude, and whether there is an inflection point. By calculating the Euclidean distance or similarity with each reference curve in the feature space, the system determines the target shape that best matches it and finally directly outputs the calibrated crimping quality associated with the target shape as the judgment result.

[0052] For example, the system does not directly store the complete curve. Instead, it defines a set of quantification rules or characteristic value ranges describing the reference shape for each quality state. For instance, a qualified shape requires a final resistance value of less than 5mΩ and a fluctuation of less than ±0.5mΩ throughout the entire process. During testing, the system analyzes the resistance change curve in real time, calculates whether it conforms to the rule set of a certain type of reference shape, and determines the shape corresponding to the rule that fully conforms or has the highest degree of conformity as the target shape. It then immediately calls the calibration crimping quality (such as "qualified") bound to that shape for output. (Refer to...) Figure 2 , Figure 2The characteristics of curve a are: the resistance decreases uniformly from 20.0 mΩ, stabilizes at 3.5 mΩ (<5 mΩ) after 200 ms, and the fluctuation is <±0.2 mΩ throughout the process, which fully meets the judgment characteristics of a steady decrease, so the crimping quality is judged as "qualified"; the characteristics of curve b are: the fluctuation amplitude during the decrease reaches a maximum of ±6.5 mΩ (far greater than ±2 mΩ), the resistance fluctuates violently between 18-21.5 mΩ in the stabilization stage, and finally stabilizes at 20.0 mΩ (>10 mΩ), so the crimping quality is judged as "unqualified (poor connection)"; the characteristics of curve c are: the resistance value drops to the lowest value of 6.0 mΩ after 200 ms, then rebounds rapidly, and stabilizes at 13.0 mΩ after 300 ms, with a rebound amplitude of 116.7% ((13.0-6.0) / 6.0≈116.7%>50%), which meets the judgment condition of potential cracks, so the crimping quality is judged as "unqualified (potential cracks)".

[0053] In another feasible implementation, step S30 may include step B31: Step B31: Determine the resistance change parameter based on the resistance change of the real-time resistance value during the crimping process, and input the resistance change parameter into the pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0054] It should be noted that resistance change parameters refer to a set of characteristic quantities extracted from the sequence data of real-time resistance values ​​changing over time using specific algorithms, used to quantitatively describe the resistance change. These parameters are not simply instantaneous resistance values ​​or eventual stable values, but rather core characteristics that digitally characterize the dynamic behavior of resistance from statistical, time-domain analysis, or signal processing perspectives. These characteristics include overall level, degree of fluctuation, rate of change, and sharpness of shape, thus providing structured and computable data input for subsequent rule-based logical judgments or model-based intelligent classification.

[0055] It is understandable that manually defining rules or morphological matching to evaluate complex resistance change curves has limitations such as limited rule coverage, difficulty in quantifying subtle features, and poor adaptability to new defect patterns. Therefore, this implementation method employs a technique of extracting quantified resistance change parameters and using a pre-trained classification model for intelligent recognition. It automatically calculates a set of quantified parameters—resistance change parameters—characterizing the core statistical and shape features of dynamic behavior from real-time resistance sequences, and inputs them into a classification model trained using historical data, such as a support vector machine or neural network. This avoids the inherent subjectivity, rigidity, and insufficient ability to handle high-dimensional and nonlinear feature relationships inherent in rules based on human experience. It achieves efficient, objective, adaptive, and intelligent classification and evaluation of crimping quality, especially complex or composite defects, significantly improving the automation level and robustness of the detection system.

[0056] In the specific implementation process, step B31 may include steps B311 to B312: Step B311: Determine the average resistance value, standard deviation of resistance fluctuation, minimum descent slope, resistance stabilization time, and kurtosis index based on the resistance change of the real-time resistance value during the crimping process. It should be noted that the average resistance value is the arithmetic mean of all real-time resistance values ​​during the effective monitoring period of the entire crimping process. This parameter reflects the macroscopic conductivity of the contact interface after the cable terminal is crimped, and is a basic statistical indicator for evaluating the quality of the contact. Its unit is usually mΩ. A low and stable average resistance value usually means that a low-resistance, large-area metallic contact has been formed.

[0057] The standard deviation of resistance fluctuation is a statistic used to quantify the dispersion of real-time resistance values ​​around the average resistance value. This parameter calculates the deviation of the real-time resistance value sequence from the average resistance value. The larger the standard deviation, the more drastic and unstable the resistance value fluctuations during the crimping process. This parameter can effectively identify defect states such as incomplete connections that are accompanied by continuous and large resistance fluctuations.

[0058] The minimum slope of decrease refers to the maximum reduction in resistance per unit time during the resistance decrease phase of the resistance change curve, i.e., the maximum absolute value of the negative slope. This parameter characterizes the rate at which resistivity rapidly decreases during the initial or middle stages of crimping, when the metal material undergoes plastic deformation and the contact interface forms rapidly. This parameter is crucial for capturing the initial response of crimping dynamics and determining whether the crimping action is forceful and effective.

[0059] Resistance settling time refers to the time elapsed from the start of the crimping process until the real-time resistance value reaches and remains in a relatively stable quasi-steady state with minimal fluctuations. This parameter measures the time cost and the length of the dynamic process required for the crimping process to reach the final stable contact state. An excessively long settling time may indicate insufficient material flow or intermittent contact problems.

[0060] Kurtosis is a statistical characteristic parameter used to describe the probability distribution of a real-time resistance value sequence. It measures whether the distribution curve is sharper (higher peaks) or flatter (lower kurtosis) compared to a normal distribution. In crimping quality assessment, a high kurtosis value may indicate abnormal, sharp pulses or abrupt changes in the resistance data (such as instantaneous contact failure spikes), which is important for detecting sporadic, drastic micro-events (such as the instantaneous propagation of microcracks).

[0061] Step B312: Input the average resistance value, the standard deviation of resistance fluctuation, the minimum descent slope, the resistance stabilization time, and the kurtosis index into the pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0062] Understandably, not all statistics extracted from resistance sequences possess equal discriminative power. Arbitrary or empirical selection of feature parameters can lead to inefficient models, insufficient recognition accuracy, and difficulty in consistently reflecting specific physical defects. Therefore, this implementation employs a technique that precisely defines and combines a set of multi-dimensional feature parameters with clear physical meaning and strong discriminative power. Specifically, it extracts the average resistance value to assess the overall conductivity level, the standard deviation of resistance fluctuations to quantify process stability, the minimum descent slope to characterize initial crimping efficiency, the resistance stabilization time to measure dynamic convergence speed, and the kurtosis index to capture abnormally sharp pulses. This effectively avoids the problems of low model classification accuracy and poor generalization ability caused by using single or arbitrary features, which result in incomplete characterization of complex defect patterns and weak correlation between features and defect types. It provides standardized inputs with high information density and strong physical interpretability for the classification model, thereby significantly improving the accuracy, reliability, and ability to distinguish different defects in the intelligent assessment system.

[0063] For example, after the crimping process is completed, the signal processing system calculates the arithmetic mean of the entire monitoring period from the stored real-time resistance value sequence as the average resistance value, calculates the standard deviation of the sequence as the resistance fluctuation standard deviation, finds the maximum value of the change in resistance per unit time during the resistance decrease phase using the finite difference method as the minimum decrease slope, and calculates the time from the start of crimping until the resistance fluctuation enters a preset threshold range as the resistance stabilization time. The system also calculates the distribution sharpness based on the fourth-order central moment and standard deviation of the sequence as the kurtosis index. Subsequently, these five calculated parameter values ​​are combined into a feature vector, which is input in real-time to an SVM classification model deployed in an embedded processor (such as an STM32F4) and trained with historical data. This model, through internal calculations, directly outputs the corresponding quality classification label, such as "qualified," "unqualified (loose connection)," or "unqualified (potential crack)," as the final crimping quality judgment result.

[0064] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in Embodiment 1 above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 Before step S20, the cable terminal crimping quality inspection method may further include steps S01-S02: Step S01: Amplify the real-time voltage signal to obtain an amplified voltage signal; It should be noted that amplified voltage signal refers to the signal obtained by linearly amplifying the real-time voltage signal through an amplifier circuit with a gain greater than 1 (such as 100 times). This increases the amplitude of the original weak signal, matches the input range of the analog-to-digital converter, and improves the signal-to-noise ratio of the entire measurement link. This allows useful voltage change information to be detected and processed more accurately by subsequent circuits, avoiding being drowned out by the system's background noise.

[0065] Step S02: Filter the amplified voltage signal to obtain a target voltage signal, and use the target voltage signal as the real-time voltage signal to perform the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal.

[0066] It should be noted that the target voltage signal refers to the final voltage signal obtained after filtering the amplified voltage signal, intended for use in resistance calculation. The purpose of filtering is to specifically suppress or remove various interference noises mixed in with the amplified voltage signal, such as mechanical vibrations and electromagnetic interference from the crimping machine, while retaining or restoring the effective voltage component purely (or primarily) generated by the excitation current flowing through the contact resistance of the cable terminals. This target voltage signal is purified voltage data that more accurately reflects the contact state. Using it as a real-time voltage signal for subsequent resistance calculations can significantly improve the accuracy and stability of the real-time resistance value.

[0067] Understandably, the raw real-time voltage signal directly acquired by the voltage needle is extremely weak, typically in the microvolt range. Furthermore, in the complex crimping environment, this signal is inevitably subject to strong noise interference introduced by mechanical vibrations of the crimping machine and electromagnetic coil radiation. Without processing, the calculated real-time resistance value would contain significant errors and be unreliable. Therefore, this embodiment further amplifies the weak real-time voltage signal linearly into an amplified voltage signal using a low-noise amplifier to increase the signal amplitude, improve the signal-to-noise ratio, and adapt to subsequent circuitry. Then, the amplified voltage signal undergoes targeted filtering to remove interference noise in specific frequency bands, resulting in a clean target voltage signal for resistance calculation. This approach fundamentally avoids the problems of the raw signal being overwhelmed by system noise due to its low amplitude, and the distortion and jumps in resistance measurement results caused by direct coupling from strong environmental interference (especially 200-500Hz mechanical vibration noise). It effectively extracts and purifies the voltage signal reflecting the true contact state, providing a reliable data foundation for subsequent high-precision calculation of the real-time resistance value, thus ensuring the accuracy of the final quality assessment.

[0068] For example, during the crimping process, the microvolt-level real-time voltage signal acquired by the voltage needle is first fed into a signal amplification circuit consisting of a low-noise instrumentation amplifier (such as an AD620). This circuit linearly amplifies the signal with a fixed gain of 100 times, thereby outputting an amplified voltage signal with an amplitude increased to the millivolt level. Subsequently, this amplified voltage signal is input to an active low-pass filter consisting of an operational amplifier (e.g., with a cutoff frequency set to 500Hz) to filter out high-frequency electromagnetic noise. The filtered signal is the target voltage signal, which serves as the real-time voltage signal used for subsequent calculations of the real-time resistance value.

[0069] In this embodiment, by first amplifying the real-time voltage signal to improve the signal-to-noise ratio and then filtering the amplified voltage signal to suppress interference, the cascaded processing scheme avoids the problems of the original signal amplitude being submerged by the system background noise due to its low value, and the serious distortion of the voltage measurement signal caused by the direct coupling of strong mechanical vibration and electromagnetic interference at the crimping site. This enables the reliable extraction and purification of weak effective voltage components from the strong noise background, thereby laying an accurate and stable data foundation for subsequent high-precision calculation of real-time resistance values.

[0070] In one feasible implementation, the step of filtering the amplified voltage signal to obtain the target voltage signal in step S02 may include step A021: Step A021: The real-time voltage signal is subjected to low-pass filtering and notch filtering in sequence to obtain the target voltage signal, wherein the sampling frequency corresponding to the real-time voltage signal is the first sampling frequency.

[0071] It should be noted that low-pass filtering is a signal processing step that allows components of a signal below a certain cutoff frequency to pass through, while significantly attenuating components above that cutoff frequency. In this embodiment, the main function of this step is to pre-filter out high-frequency noise (typically above 500Hz) generated by the crimping machine's electromagnetic coil, switching power supply, etc., from the amplified voltage signal. This prevents these high-frequency interferences from causing spectral aliasing during subsequent sampling, thereby creating a clean frequency band foundation for subsequent, more refined filtering and avoiding high-frequency noise contamination of the target signal frequency band.

[0072] Notch filtering is a special type of band-stop filtering. Its characteristic is that it produces deep attenuation within a very narrow frequency band centered on a specific center frequency (e.g., 300Hz), while having minimal impact on other frequency components outside this band. Its function is to specifically and precisely filter out strong interference in specific frequency bands remaining in the signal after low-pass filtering, particularly the periodic noise mainly concentrated in the 200-500Hz range generated by hydraulic shock and mechanical vibration from crimping machines. This eliminates critical interference while preserving, to the greatest extent possible, the effective voltage signal reflecting changes in contact resistance.

[0073] The first sampling frequency refers to the specific sampling rate used when performing analog-to-digital conversion on real-time voltage signals, employing a low-pass filter and notch filter signal processing path, such as 1kHz. This frequency setting must satisfy the Nyquist sampling theorem to ensure distortion-free reconstruction of the filtered signal and match the noise frequency band targeted by the notch filter (e.g., 200-500Hz). It is a key parameter for achieving effective dynamic measurement under this path.

[0074] Understandably, due to the specific and concentrated frequency distribution of interference noise at the crimping site, such as the dominant frequency of mechanical vibration in the 200-500Hz range, a single broad-band filter cannot effectively suppress such strong narrowband interference while preserving the useful signal with high fidelity. Therefore, this implementation employs a targeted approach using a two-stage cascaded low-pass filter and notch filter. First, a low-pass filter (e.g., with a cutoff frequency of 500Hz) is used to filter out all high-frequency noise to prevent aliasing and simplify the signal. Then, a notch filter with a center frequency precisely matched to the dominant frequency of mechanical vibration (e.g., 300Hz) deeply attenuates the residual narrowband interference. This avoids the problem of periodic jumps and distortions in resistance calculations caused by strong periodic mechanical vibration noise directly superimposed on the useful signal frequency band. It achieves accurate and high-fidelity extraction of the voltage signal reflecting contact resistance under strong vibration conditions, thereby ensuring the accuracy and stability of dynamic resistance measurement.

[0075] For example, the system is configured with an analog-to-digital converter such as the ADS1115 to digitize the amplified real-time voltage signal at a sampling frequency of 860 SPS (i.e., the first sampling frequency). Subsequently, the digital signal processor first calls a digital low-pass filter (such as one based on an FIR or IIR structure) with a cutoff frequency of 500 Hz to filter out high-frequency electromagnetic noise. Then, the low-pass filtered signal is sent to a second-order infinite impulse response notch filter with a center frequency of 300 Hz and a quality factor Q of 5 to deeply attenuate the residual 200-500 Hz mechanical vibration noise. Finally, the purified digital voltage sequence output from the notch filter is defined as the target voltage signal for resistance calculation.

[0076] In another feasible implementation, the step of filtering the amplified voltage signal to obtain the target voltage signal in step S02 may include step B021: Step B021: The real-time voltage signal is subjected to low-pass filtering and wavelet transform in sequence to obtain a multi-scale decomposed signal, and the high-frequency part of the multi-scale decomposed signal is denoised to obtain the target voltage signal. The sampling frequency corresponding to the real-time voltage signal is the second sampling frequency, which is higher than the second sampling frequency.

[0077] It should be noted that wavelet transform is an alternative signal processing step to notch filtering. This step is a time-frequency analysis method that decomposes the signal into different time and frequency scales by performing inner product operations on the signal with a series of scaled and translated wavelet basis functions. Its function is to better handle non-stationary signals, i.e., signals whose statistical characteristics change over time. It can simultaneously provide localized information about the signal in both the time and frequency domains, thereby more effectively separating and identifying time-varying interference components mixed in with the valid signal.

[0078] Multiscale decomposition of a signal is a set of signal components obtained by wavelet transforming an amplified voltage signal. These components contain detailed and approximate information of the original signal at different scales (corresponding to different frequency ranges) and at different time positions. This can decouple complex mixed signals into sub-signals of different frequency bands, allowing for targeted denoising of the high-frequency details representing noise, while preserving or reconstructing the low-frequency approximations representing the effective signal.

[0079] The second sampling frequency refers to a specific sampling rate higher than the first sampling frequency, such as 2kHz, used when performing analog-to-digital conversion on real-time voltage signals using a signal processing path involving low-pass filtering and wavelet transform. The reason for using a higher sampling rate is that wavelet transform, especially its high-frequency detail analysis, requires a wider signal bandwidth and higher time resolution to capture transient features, ensuring the accuracy of decomposition and the effectiveness of denoising, thus meeting the more stringent requirements for processing non-stationary signals.

[0080] Understandably, interference noise during the crimping process may be non-stationary, meaning its statistical characteristics change over time, such as intermittent impacts and spectral drift. Fixed-frequency notch filters have limited ability to track and suppress such time-varying interference. Therefore, this implementation employs a time-frequency analysis technique combining low-pass filtering and wavelet transform. The low-pass filter first removes fundamental high-frequency noise, then wavelet transform decomposes the signal into multi-scale decomposed signals of different scales, and adaptively denoises the high-frequency details. Simultaneously, a higher second sampling frequency is used to capture transient details. This approach avoids the problem of traditional filtering methods' poor suppression of time-varying and non-stationary noise, leading to signal quality degradation under complex operating conditions. It achieves more robust and adaptive extraction of the effective voltage signal in harsher or dynamically changing interference environments, improving the overall stability and applicability of the system.

[0081] For example, the system employs a higher-performance analog-to-digital converter, such as a 24-bit Σ-Δ ADS1120, to sample the signal at a sampling frequency of 2 kHz, which is a second sampling frequency higher than the first sampling frequency. The digital signal is first preprocessed by a digital low-pass filter with a cutoff frequency of 500 Hz. Subsequently, the system uses a multi-resolution discrete wavelet transform algorithm, such as using the Daubechies db4 wavelet basis for 5-level decomposition, to decompose the filtered signal into a set of approximate coefficients and detail coefficients containing different frequency components, thus obtaining a multi-scale decomposed signal. Next, a soft thresholding function is applied to the detail coefficients representing high-frequency noise, such as the details at levels 2 to 4, for denoising. Finally, wavelet reconstruction is performed using the denoised coefficients, and the recovered time-domain signal is defined as the final target voltage signal.

[0082] In addition, you can refer to Figure 4 The original signal is the real-time voltage signal before filtering. The pre-stage filtering is low-pass filtering, and the post-stage filtering is notch filtering or wavelet transform. The clean signal is the target voltage signal. The effects of the two implementation methods—notch filtering and wavelet transform—are compared in Table 1 below: Table 1

[0083] This indicates that when intermittent impacts or material flow in the crimping machine cause spectral drift, the wavelet scheme improves the noise suppression rate to 95% and reduces the misjudgment rate of non-stationary signals by 40%. Although the computational load increases slightly, the overall stability and versatility are superior.

[0084] For example, to help understand the implementation process of the cable terminal crimping quality inspection method obtained in this embodiment combined with the above embodiment one, please refer to... Figure 5 , Figure 5 A schematic diagram of a system framework for a method to inspect the crimping quality of cable terminals is provided, specifically: The system hardware consists of four closely cooperating closed-loop detection modules: a constant current source module outputs DC current to provide stable excitation for the measurement circuit; in the four-wire probe, the current needle applies excitation, and the voltage needle directly collects the minute voltage at the crimping point, eliminating the influence of wire resistance from a physical structure perspective; the signal acquisition chain includes a low-noise amplifier, an anti-aliasing filter, and an analog-to-digital converter, which amplifies, filters, and converts μV-level voltage signals into digital signals; and the data processing unit uses an MCU to run filtering algorithms and quality assessment models in real time.

[0085] Further, please refer to Figure 6 , Figure 6 A schematic diagram of the crimping machine used in a cable terminal crimping quality inspection method is provided, specifically: Figure 6 In the diagram, M represents the crimping die, P represents the copper-aluminum cable, C represents the constant current source, C1 represents the first current needle, C2 represents the second current needle, T represents the cable terminal, V1 represents the first voltage needle, and V2 represents the second voltage needle.

[0086] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the cable terminal crimping quality inspection method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0087] This application also provides a cable terminal crimping quality testing device, please refer to... Figure 7 The cable terminal crimping quality testing device includes: The crimping acquisition module 10 is used to excite the cable terminal through a current needle and acquire the voltage on the cable terminal through a voltage needle during the crimping process to obtain a real-time voltage signal. The resistance monitoring module 20 is used to determine the real-time resistance value of the cable terminal based on the real-time voltage signal. The quality assessment module 30 is used to assess the crimping quality of the cable terminal based on the resistance change of the real-time resistance value during the crimping process.

[0088] Optionally, the current needle includes a first current needle and a second current needle. A standard resistor is also connected in series in the excitation circuit formed by the first current needle, the cable terminal, and the second current needle. The resistance monitoring module 20 is further used for: Monitor the reference voltage across the standard resistor and determine the detection resistance value of the cable terminal based on the detection voltage value corresponding to the real-time voltage signal; The detected resistance value is calibrated based on the reference voltage value and the reference resistance value of the standard resistor to obtain the real-time resistance value of the cable terminal.

[0089] Optionally, the cable terminal crimping quality detection device further includes a signal processing module 40, which is used for: The real-time voltage signal is amplified to obtain an amplified voltage signal; The amplified voltage signal is filtered to obtain a target voltage signal, which is then used as the real-time voltage signal to perform the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal.

[0090] Optionally, the signal processing module 40 is further configured to: The real-time voltage signal is sequentially subjected to low-pass filtering and notch filtering to obtain the target voltage signal, wherein the sampling frequency corresponding to the real-time voltage signal is the first sampling frequency; or The real-time voltage signal is subjected to low-pass filtering and wavelet transform in sequence to obtain a multi-scale decomposed signal. The high-frequency part of the multi-scale decomposed signal is then denoised to obtain the target voltage signal. The sampling frequency corresponding to the real-time voltage signal is a second sampling frequency, which is higher than the second sampling frequency.

[0091] Optionally, the quality assessment module 30 is further configured to: A resistance change curve is constructed based on the real-time resistance value during the crimping process, and the crimping quality of the cable terminal is evaluated based on the resistance change curve; or Based on the resistance change of the real-time resistance value during the crimping process, the resistance change parameter is determined, and the resistance change parameter is input into the pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0092] Optionally, the quality assessment module 30 is further configured to: The shape of the resistance change curve is compared with multiple preset reference shapes to determine the target shape that matches the curve shape among the reference shapes. Obtain the calibration crimping quality corresponding to the target shape, and use the calibration crimping quality as the crimping quality of the cable terminal.

[0093] Optionally, the quality assessment module 30 is further configured to: The average resistance value, standard deviation of resistance fluctuation, minimum descent slope, resistance stabilization time and kurtosis index are determined based on the resistance change of the real-time resistance value during the crimping process. The average resistance value, the standard deviation of resistance fluctuation, the minimum descent slope, the resistance stabilization time, and the kurtosis index are input into a pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

[0094] The cable terminal crimping quality testing device provided in this application, employing the cable terminal crimping quality testing method described in the above embodiments, can solve the technical problem that current evaluation schemes for cable terminal crimping quality cannot simultaneously achieve real-time performance, non-destructive nature, and high precision. Compared with the prior art, the beneficial effects of the cable terminal crimping quality testing device provided in this application are the same as those of the cable terminal crimping quality testing method provided in the above embodiments, and other technical features of the cable terminal crimping quality testing device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0095] This application provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the cable terminal crimping quality detection method in Embodiment 1 above.

[0096] The following is for reference. Figure 8 The diagram illustrates a structural schematic of an electronic device suitable for implementing embodiments of this application. The electronic devices in these embodiments may include, but are not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 8 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0097] like Figure 8As shown, the electronic device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. The random access memory 1004 also stores various programs and data required for the operation of the electronic device. The processing unit 1001, the read-only memory 1002, and the random access memory 1004 are interconnected via a bus 1005. An input / output interface 1006 is also connected to the bus. Typically, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. The communication device 1009 allows the electronic device to communicate wirelessly or wiredly with other devices to exchange data. Although the diagrams show electronic devices with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented alternatively.

[0098] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from read-only memory 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0099] The electronic device provided in this application, employing the cable terminal crimping quality detection method described in the above embodiments, can solve the technical problem that current evaluation schemes for cable terminal crimping quality cannot simultaneously achieve real-time performance, non-destructive nature, and high precision. Compared with the prior art, the beneficial effects of the electronic device provided in this application are the same as those of the cable terminal crimping quality detection method provided in the above embodiments, and other technical features of this electronic device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0100] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0101] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0102] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the cable terminal crimping quality detection method in the above embodiments.

[0103] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0104] The aforementioned computer-readable storage medium may be included in an electronic device or may exist independently without being assembled into an electronic device.

[0105] The aforementioned computer-readable storage medium carries one or more programs that, when executed by an electronic device, cause the electronic device to: excite the cable terminal by a current needle and collect the voltage on the cable terminal by a voltage needle during the crimping process to obtain a real-time voltage signal; determine the real-time resistance value of the cable terminal based on the real-time voltage signal; and evaluate the crimping quality of the cable terminal based on the resistance change of the real-time resistance value during the crimping process.

[0106] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0107] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0108] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0109] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described cable terminal crimping quality detection method. This solves the technical problem that current cable terminal crimping quality evaluation schemes cannot simultaneously achieve real-time performance, non-destructive operation, and high precision. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the cable terminal crimping quality detection method provided in the above embodiments, and will not be elaborated upon here.

[0110] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for inspecting the crimping quality of cable terminals, characterized in that, The method for detecting the quality of cable terminal crimping includes: During the crimping process of the cable terminals, the cable terminals are excited by a current needle, and the voltage on the cable terminals is collected by a voltage needle to obtain a real-time voltage signal; The real-time resistance value of the cable terminal is determined based on the real-time voltage signal; The crimping quality of the cable terminal is evaluated based on the resistance change of the real-time resistance value during the crimping process.

2. The cable terminal crimping quality inspection method as described in claim 1, characterized in that, The current needle includes a first current needle and a second current needle. A standard resistor is connected in series in the excitation circuit formed by the first current needle, the cable terminal, and the second current needle. The step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal includes: Monitor the reference voltage value across the standard resistor, and determine the detection resistance value of the cable terminal based on the detection voltage value corresponding to the real-time voltage signal; The detected resistance value is calibrated based on the reference voltage value and the reference resistance value of the standard resistor to obtain the real-time resistance value of the cable terminal.

3. The cable terminal crimping quality inspection method as described in claim 1, characterized in that, Before the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal, the method further includes: The real-time voltage signal is amplified to obtain an amplified voltage signal; The amplified voltage signal is filtered to obtain a target voltage signal, which is then used as the real-time voltage signal to perform the step of determining the real-time resistance value of the cable terminal based on the real-time voltage signal.

4. The cable terminal crimping quality inspection method as described in claim 3, characterized in that, The step of filtering the amplified voltage signal to obtain the target voltage signal includes: The real-time voltage signal is sequentially subjected to low-pass filtering and notch filtering to obtain the target voltage signal, wherein the sampling frequency corresponding to the real-time voltage signal is the first sampling frequency; or The real-time voltage signal is subjected to low-pass filtering and wavelet transform in sequence to obtain a multi-scale decomposed signal. The high-frequency part of the multi-scale decomposed signal is then denoised to obtain the target voltage signal. The sampling frequency corresponding to the real-time voltage signal is a second sampling frequency, which is higher than the second sampling frequency.

5. The cable terminal crimping quality inspection method as described in claim 1, characterized in that, The step of evaluating the crimping quality of the cable terminal based on the resistance change of the real-time resistance value during the crimping process includes: A resistance change curve is constructed based on the real-time resistance value during the crimping process, and the crimping quality of the cable terminal is evaluated based on the resistance change curve; or Based on the resistance change of the real-time resistance value during the crimping process, the resistance change parameter is determined, and the resistance change parameter is input into the pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

6. The cable terminal crimping quality inspection method as described in claim 5, characterized in that, The step of evaluating the crimping quality of the cable terminal based on the resistance change curve includes: The shape of the resistance change curve is compared with multiple preset reference shapes to determine the target shape that matches the curve shape among the reference shapes. Obtain the calibration crimping quality corresponding to the target shape, and use the calibration crimping quality as the crimping quality of the cable terminal.

7. The cable terminal crimping quality inspection method as described in claim 5, characterized in that, The step of determining the resistance change parameter based on the resistance change during the crimping process using the real-time resistance value, and inputting the resistance change parameter into a pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model includes: The average resistance value, standard deviation of resistance fluctuation, minimum descent slope, resistance stabilization time and kurtosis index are determined based on the resistance change of the real-time resistance value during the crimping process. The average resistance value, the standard deviation of resistance fluctuation, the minimum descent slope, the resistance stabilization time, and the kurtosis index are input into a pre-trained classification model to obtain the crimping quality of the cable terminal output by the classification model.

8. A device for detecting the crimping quality of cable terminals, characterized in that, The cable terminal crimping quality testing device includes: The crimping acquisition module is used to excite the cable terminal through a current needle and acquire the voltage on the cable terminal through a voltage needle during the crimping process to obtain a real-time voltage signal. A resistance monitoring module is used to determine the real-time resistance value of the cable terminal based on the real-time voltage signal; The quality assessment module is used to evaluate the crimping quality of the cable terminals based on the resistance change of the real-time resistance value during the crimping process.

9. An electronic device, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the cable terminal crimping quality inspection method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the cable terminal crimping quality detection method as described in any one of claims 1 to 7.

Images