A method and system for testing transmission performance of vehicle-mounted Ethernet wiring harness

Abstract

The present invention relates to a vehicle-mounted Ethernet harness transmission performance test method and system, which includes obtaining vehicle-mounted Ethernet harness test data that works well, including environmental conditions and transmission performance parameters; taking environmental conditions as input and transmission performance parameters as standard output, constructing a test standard model to measure standard transmission performance parameters under different environmental conditions; obtaining the measured transmission performance parameters of the harness to be tested under a combination of multiple environmental conditions, and inputting the multiple environmental condition combinations into the test standard model, outputting the corresponding standard transmission performance parameters to compare the measured transmission performance parameters with the standard transmission performance parameters, and judging whether the harness to be tested meets the unified standard. The present invention solves the problem that the prior art lacks strict test standards, resulting in inconsistent transmission performance quality of harnesses.

Description

Technical Field

[0001] The invention belongs to the technical field of wire harness testing, and relates to a method and system for testing the transmission performance of an in-vehicle Ethernet wire harness. Background Art

[0002] The automotive wiring harness is an important electrical component in the vehicle, responsible for connecting various sensors, control units, lights, motors and other devices to achieve electrical signal transmission inside the vehicle. With the improvement of the level of automotive electronics, the complexity and importance of vehicle wiring harnesses are also increasing. In order to ensure the performance, safety and reliability of the vehicle, it is essential to conduct comprehensive parameter performance testing and fault prediction of automotive wiring harnesses.

[0003] At present, people use a variety of transmission performance parameters to determine whether the automotive wiring harness is qualified, and simulate the transmission performance of the automotive Ethernet wiring harness under different environmental conditions. However, most of the existing technologies lack a unified test standard, resulting in uneven transmission performance of automotive wiring harnesses that can pass the test, which in turn leads to people easily underestimating or overestimating the transmission performance of the wiring harness in actual use and making wrong judgments. Summary of the invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a method and system for testing the transmission performance of an in-vehicle Ethernet harness, which aims to collect test data of in-vehicle Ethernet harnesses that have worked well in historical periods, construct an artificial intelligence model between different environmental conditions and harness transmission performance parameters as a standard test model, and compare the test results of the harness to be tested with the standard test model to determine whether the transmission performance of the harness to be tested is qualified.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present application provides a method for testing the transmission performance of an in-vehicle Ethernet harness, comprising the following steps:

[0007] S1. Obtaining transmission performance parameters of independent communication channels of vehicle Ethernet harnesses through a multi-port vector network analyzer; the transmission performance parameters include characteristic impedance, insertion loss, return loss, longitudinal transformation loss, and longitudinal conversion transmission loss;

[0008] S2. Control the combination of multiple environmental conditions and record the changes of the transmission performance parameters;

[0009] S3, obtaining the vehicle Ethernet harness test data that works well in steps S1-S2, and constructing a test standard model; the test data includes environmental conditions and transmission performance parameters; the test standard model uses environmental conditions as input and transmission performance parameters as standard output, and is used to measure standard transmission performance parameters under different environmental conditions;

[0010] S4. Obtaining the measured transmission performance parameters of the wiring harness to be tested under various combinations of environmental conditions, and inputting the various combinations of environmental conditions into the test standard model to output corresponding standard transmission performance parameters;

[0011] S5. Compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standards.

[0012] Furthermore, the test standard model is configured as a random forest model, which takes environmental conditions as features and transmission performance parameters as labels; during the model training process, the data set samples are divided into five parts, four of which are training sets and one is a prediction set, and the prediction performance of the model is verified by cross-checking five times.

[0013] Furthermore, the comparison of the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested complies with the unified standard includes the following steps:

[0014] Calculate the transmission performance difference between the measured transmission performance parameter and the standard transmission performance parameter;

[0015] Divide the transmission performance difference by the standard transmission performance parameter to obtain the relative deviation of the transmission performance;

[0016] When the relative deviation of the transmission performance exceeds a set threshold, it is determined that the wiring harness does not meet the unified standard;

[0017] When the relative deviation of the transmission performance does not exceed a set threshold, it is determined that the wiring harness meets the unified standard.

[0018] Furthermore, the transmission performance relative deviation is calculated as follows:

[0019] ,

[0020] In the formula, X r Indicates the relative deviation of transmission performance; X s Indicates the measured transmission performance parameters; X b Indicates standard transmission performance parameters.

[0021] Further, the characteristic impedance, used to describe the relationship between voltage and current in the wiring harness, is determined by measuring the reflection coefficient and based on the reflection coefficient and the known wiring harness length and material properties;

[0022] The insertion loss refers to the loss of a signal when it passes through a wiring harness, and is measured by comparing the strength of the input signal with the output signal;

[0023] The return loss is used to reflect the reflection of the signal due to impedance mismatch. It is calculated by first sending a signal through the vector detector and then measuring the strength of the reflected signal.

[0024] The longitudinal conversion loss is used to measure the signal loss when the wire harness is converted between different connections or connectors. The loss between the connection points is evaluated by connecting the wire harness to different adapters or modules and measuring the signal strength change using a vector detector.

[0025] The longitudinal conversion transmission loss is the penetration loss of the signal between different channels or connection components, and is determined by comparing the signal strength after direct connection and passing through the connection component through a vector detector.

[0026] Furthermore, the controlling the combination of multiple environmental conditions and recording the changes of the transmission performance parameters comprises the following steps:

[0027] S21. Use an orthogonal approach to set a combination of multiple environmental conditions;

[0028] S22. Test the wiring harness under each combination of environmental conditions;

[0029] S23. According to the test results, record the transmission performance parameters under different combinations of environmental conditions.

[0030] Furthermore, the environmental conditions include temperature, humidity and vibration level, wherein:

[0031] The temperature is set at different temperature levels using a temperature control box to ensure that the wiring harness is within the required temperature range during testing;

[0032] The humidity is adjusted by using a humidifier, and the process is monitored and controlled in real time by using sensors;

[0033] According to the vibration degree, the test device is placed on a vibration table and different vibration frequencies and amplitudes are set as needed.

[0034] In a second aspect, a vehicle-mounted Ethernet harness transmission performance test system is applied to a vehicle-mounted Ethernet harness transmission performance test method as described above, including a control module, a standard module and a decision module, wherein the control module, the standard module and the decision module are communicatively connected, wherein:

[0035] The control module is used to control a combination of multiple environmental conditions to test the wiring harness to be tested and obtain the measured transmission performance parameters;

[0036] The standard module is used to input a combination of multiple environmental conditions into the test standard model to obtain standard transmission performance parameters;

[0037] The decision module is used to compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standard.

[0038] Furthermore, the control module tests the wiring harness to be tested three times in total. When the variance of the three test results is less than a preset variance, the average value is taken as the result of the three tests; when the variance of the three test results is greater than or equal to the preset variance, the wiring harness to be tested is determined to be unqualified.

[0039] Furthermore, the decision module also includes a result output module, which is used to visually display the measured transmission performance parameters that do not meet the unified standard when the wiring harness to be tested does not meet the unified standard.

[0040] Beneficial effects of the present invention:

[0041] (1) The vehicle Ethernet harness test data that works well in the acquisition step includes environmental conditions and transmission performance parameters; the environmental conditions are used as input and the transmission performance parameters are used as standard output to construct a test standard model to measure the standard transmission performance parameters under different environmental conditions; the measured transmission performance parameters of the harness to be tested are obtained under a combination of multiple environmental conditions, and the multiple environmental condition combinations are input into the test standard model, and the corresponding standard transmission performance parameters are output to compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the harness to be tested meets the unified standard. The present invention solves the problem that the prior art lacks strict test standards, resulting in inconsistent transmission performance quality of the harness.

[0042] (2) The random forest model is used as the test standard model to quantify the relationship between environmental conditions and transmission performance parameters, thereby improving the accuracy of test standard judgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0044] Figure 1 The present invention is a flow chart of a method for testing the transmission performance of an in-vehicle Ethernet harness.

[0045] Figure 2 This is a flow chart of comparing the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standard in one embodiment of the present invention.

[0046] Figure 3 The structure diagram of a vehicle-mounted Ethernet harness transmission performance test system in the present invention. DETAILED DESCRIPTION

[0047] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0048] See also Figure 1-Figure 3 In a first aspect, the present application provides a method for testing the transmission performance of an in-vehicle Ethernet harness, comprising the following steps:

[0049] S1. Obtain the transmission performance parameters of the independent communication channel of the vehicle Ethernet harness through a multi-port vector network analyzer;

[0050] In this embodiment, the multi-port vector network analyzer is an instrument used to evaluate the transmission performance of high-frequency signals, and is suitable for testing the performance of transmission media such as wiring harnesses. The first step of the test is to ensure that the device is connected correctly and perform necessary self-tests to confirm that it is working properly. Subsequently, the user needs to configure the device parameters according to the specific test requirements, such as selecting the appropriate frequency range and measurement type. In order to ensure the accuracy of the measurement, calibration is required, which usually includes calibration using standard conditions such as open, short circuit and load to ensure that all connections and settings are verified. After completing this process, the actual test of the wiring harness can be started, and various scattering parameters (S parameters) such as S11 reflection loss and S21 insertion loss can be recorded. These parameters can provide detailed information about the performance of the transmission medium. By performing a detailed analysis of the acquired data, the user can evaluate the key performance indicators of the wiring harness, such as insertion loss, return loss and bandwidth, so as to determine whether it meets the design standards and application requirements. The test results can not only be used directly for performance evaluation, but also generate reports to provide a basis for subsequent product development and improvement. In order to verify the consistency and reliability of the results, the user can also repeat the test of the wiring harness under different conditions according to needs. Through these systematic steps, the multi-port vector analyzer provides a comprehensive and accurate solution for the performance testing of cable harnesses, helping users ensure the effectiveness and reliability of their products in high-frequency applications.

[0051] The automotive Ethernet harness is a connection solution for the internal network of the car, supporting high-speed data transmission and communication between devices. Ethernet technology is widely used in automobiles to meet the growing demand for data transmission, especially in autonomous driving, in-vehicle entertainment systems, and smart interconnection functions. The automotive Ethernet harness is an SPE harness that meets OPEN, which is an open single-pair Ethernet (SPE) harness. This harness uses a single pair of copper cables, which has a smaller size and lighter weight than traditional multi-pair cables, and can support longer transmission distances, reducing the complexity of wiring inside the vehicle. It also provides data transmission rates of up to 100 Mbps or higher, which can meet the bandwidth requirements of in-vehicle applications. The SPE harness that meets the OPEN (Open Automotive Network) standard is designed to achieve interoperability and compatibility between devices from different manufacturers, ensuring that automotive electronic equipment can exchange data smoothly and stably. This standardized design also helps reduce manufacturing costs, simplify the supply chain, and improve the overall performance and reliability of the car.

[0052] Independent communication channels refer to channels that can independently transmit data in the same transmission system. These channels are designed not to interfere with each other, so that multiple data streams can be transmitted simultaneously, improving transmission efficiency and the overall performance of the system. Independent communication channels are generally widely used in the fields of electronic communications, networks, and signal processing. They have the characteristics of signal isolation, bandwidth allocation, and parallel transmission, allowing different channels to be allocated different bandwidths according to needs, thereby meeting the needs of various application scenarios. For example, in wireless communications and fiber optic transmission, independent communication channels can support multiple users or services at the same time without interfering with each other, improving the reliability of data transmission. In modern network architecture, this independence not only improves the transmission speed, but also provides the possibility for flexible configuration, so that the network can be optimized and adjusted according to actual needs.

[0053] Furthermore, the transmission performance parameters include characteristic impedance, insertion loss, return loss, longitudinal transformation loss and longitudinal conversion transmission loss.

[0054] In this embodiment, when testing the transmission performance parameters of the wiring harness on the multi-port vector network analyzer, the following is a detailed description of the key parameters and their testing principles:

[0055] 1) Characteristic impedance: Characteristic impedance is a parameter that describes the relationship between voltage and current in a transmission line or harness, and is usually determined by measuring the reflection coefficient. When using a network analyzer, a signal is sent to the harness to be tested and the reflection of the signal at the input end is measured. Based on the reflection coefficient and the known harness length and material properties, the characteristic impedance can be calculated to ensure the matching of the equipment.

[0056] 2) Insertion loss: Insertion loss refers to the loss of a signal when it passes through a wiring harness, and is usually measured by comparing the strength of the input signal to the output signal. The network analyzer sends a signal of known amplitude and measures the received signal strength at the output. Insertion loss is expressed in decibels (dB) and is calculated as IL = 10 * log10(Pin / Pout), where Pin is the input signal power and Pout is the output signal power.

[0057] 3) Return loss: Return loss reflects the reflection of the signal due to impedance mismatch. The network analyzer first sends a signal and then measures the strength of the reflected signal. The return loss can be calculated using the formula RL = 10 * log10(Pin / Pref), where Pref is the reflected signal power. The higher the return loss, the better the match and the smaller the reflected signal.

[0058] 4) Longitudinal conversion loss: Longitudinal conversion loss is the signal loss when the wiring harness is converted between different connections or connectors. During the test, the signal strength changes are measured by using a network analyzer through different connection methods (such as connecting the wiring harness to different adapters or modules) to evaluate the loss at these connection points.

[0059] 5) Longitudinal conversion transmission loss: Longitudinal conversion transmission loss is the penetration loss of the signal between different channels or connecting components. In the test, the network analyzer compares the signal strength after the direct connection and after passing through the connecting components. Usually multiple measurements are performed under different connection conditions to obtain a more accurate loss value.

[0060] S2. Control the combination of multiple environmental conditions and record the changes of the transmission performance parameters;

[0061] Furthermore, the controlling the combination of multiple environmental conditions and recording the changes of the transmission performance parameters comprises the following steps:

[0062] S21. Use an orthogonal approach to set a combination of multiple environmental conditions;

[0063] In this embodiment, orthogonal design is an efficient experimental method for studying the effects of multiple environmental conditions on target parameters. When implementing, first determine the factors to be studied and their corresponding multiple levels. For example, factors such as temperature, humidity, and vibration level can be considered, and three or more levels of high, medium, and low can be set for each factor. Then, using an orthogonal table (such as L9 or L16), all possible experimental combinations are systematically listed to ensure that each condition is effectively tested. This method can significantly reduce the number of experiments and avoid repeated tests.

[0064] S22. Test the wiring harness under each combination of environmental conditions;

[0065] S23. According to the test results, record the transmission performance parameters under different combinations of environmental conditions.

[0066] Furthermore, the environmental conditions include temperature, humidity and vibration level, wherein:

[0067] The temperature is set at different temperature levels using a temperature control box to ensure that the wiring harness is within the required temperature range during testing;

[0068] The humidity is adjusted by using a humidifier, and the process is monitored and controlled in real time by using sensors;

[0069] According to the vibration degree, the test device is placed on a vibration table and different vibration frequencies and amplitudes are set as needed.

[0070] S3, obtaining the vehicle Ethernet harness test data that works well in steps S1-S2, and constructing a test standard model; the test data includes environmental conditions and transmission performance parameters; the test standard model uses environmental conditions as input and transmission performance parameters as standard output, and is used to measure standard transmission performance parameters under different environmental conditions;

[0071] In this embodiment, the vehicle Ethernet harness that has been tested to work well in the historical period is used as the standard. By collecting test data to build a test standard model, the standard transmission performance parameters under different environmental conditions can be effectively evaluated. This process will provide a scientific basis for the quality control of the vehicle Ethernet harness and ensure its stability and reliability in complex environments. First, a group of vehicle Ethernet harnesses that have performed well in past tests are selected. These harnesses should be representative and cover different types and manufacturing processes. Under a standard environment, these harnesses are subjected to detailed performance tests and key parameters are recorded. At the same time, in order to ensure the comprehensiveness of the model, the impact of different environmental factors on the performance of the harness needs to be considered. By systematically analyzing the collected data, the changing trends and interrelationships of various performance indicators are deeply explored. This process can not only identify the key factors affecting performance, but also reveal the dynamic changes in the transmission performance of the harness under different environmental conditions. Based on the analysis results, a mathematical model (test standard model) is constructed to describe the transmission performance of the harness under various environmental conditions, and ensure that the model is predictive and applicable. The model should be able to reflect the impact of environmental changes on the performance of the harness in real time, and provide a reference standard for different manufacturers in the industry. Finally, the test standard model is used as a unified wire harness test standard to clarify the qualified thresholds and test processes of various performance parameters to ensure that different types of automotive Ethernet wire harnesses meet the same quality requirements in production and use.

[0072] Furthermore, the test standard model is configured as a random forest model, which takes environmental conditions as features and transmission performance parameters as labels; during the model training process, the data set samples are divided into five parts, four of which are training sets and one is a prediction set, and the prediction performance of the model is verified by cross-checking five times.

[0073] The random forest model is a powerful ensemble learning method that is widely used in classification and regression tasks. It builds multiple decision trees and combines their results to improve the accuracy and robustness of predictions. The core idea of ​​random forest is to use a voting mechanism or an average to integrate the outputs of each tree to obtain more reliable results. When building each decision tree, random forest uses a subset randomly sampled from the training data set. This method is called "bootstrap sampling", which means that each tree is trained on a different sample. In addition, random forest only randomly selects a part of the features to consider when splitting each node. This strategy effectively reduces the correlation between features, thereby enhancing the diversity of the model. In this way, random forest can not only effectively reduce the variance of the model and reduce the risk of overfitting, but also maintain good prediction performance under different data distributions. Random forest performs well in dealing with complex real-world problems, especially when the data set is large and has many features. It has strong anti-disturbance ability and is not easily affected by noise and outliers in the data. In practical applications, the random forest model can effectively capture the nonlinear relationship between input features, which is often difficult to achieve in many traditional algorithms. Its flexibility and adaptability make it applicable to various types of data, including categorical data and continuous data, and can handle missing values. In addition, when applying random forests, users only need to adjust a small number of parameters (such as the number of trees, maximum tree depth, etc.) to obtain good prediction results. Therefore, the random forest model has become a very popular and effective algorithm in the field of machine learning due to its high accuracy, interpretability and applicability, providing a reliable tool for solving complex problems.

[0074] S4. Obtaining the measured transmission performance parameters of the wiring harness to be tested under various combinations of environmental conditions, and inputting the various combinations of environmental conditions into the test standard model to output corresponding standard transmission performance parameters;

[0075] In this embodiment, the wiring harness is tested under various combinations of environmental conditions to generate measured transmission performance parameters, and these environmental condition combinations are input into the test standard model to obtain theoretical standard transmission performance parameters to facilitate comparison between the two.

[0076] S5. Compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standards.

[0077] Furthermore, the comparison of the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested complies with the unified standard includes the following steps:

[0078] Calculate the transmission performance difference between the measured transmission performance parameter and the standard transmission performance parameter;

[0079] Divide the transmission performance difference by the standard transmission performance parameter to obtain the relative deviation of the transmission performance;

[0080] When the relative deviation of the transmission performance exceeds a set threshold, it is determined that the wiring harness does not meet the unified standard;

[0081] When the relative deviation of the transmission performance does not exceed a set threshold, it is determined that the wiring harness meets the unified standard.

[0082] In this embodiment, the transmission performance of the tested wiring harness mainly includes the calculation of the transmission performance difference and the evaluation of the relative deviation. First, calculating the transmission performance difference between the measured transmission performance parameters and the standard transmission performance parameters is an important part of evaluating the performance of the wiring harness. The measured parameters are usually the actual performance values ​​obtained during the test, while the standard parameters are the ideal values ​​output according to the model. By calculating the difference between the two, the deviation between the actual performance of the wiring harness and the expected performance can be intuitively understood.

[0083] Divide the transmission performance difference by the standard transmission performance parameter to get the relative deviation of the transmission performance. This relative deviation is expressed as a percentage, which can better reflect the degree to which the harness performance deviates from expectations. The larger the relative deviation, the more significant the difference between the actual performance of the harness and the standard.

[0084] Finally, when the relative deviation of transmission performance exceeds the set threshold, the wiring harness is judged to be non-compliant with the unified standard. This set threshold is usually based on industry standards or production requirements to ensure the reliability and safety of the wiring harness. Through this quantitative evaluation, wiring harnesses that do not meet the performance standards can be effectively identified, thereby supporting subsequent quality control and improvement measures to ensure that the quality of the final product meets user needs.

[0085] Furthermore, the transmission performance relative deviation is calculated as follows:

[0086] ,

[0087] In the formula, X r Indicates the relative deviation of transmission performance; X s Indicates the measured transmission performance parameters; X b Indicates standard transmission performance parameters.

[0088] In a second aspect, a vehicle-mounted Ethernet harness transmission performance test system is applied to a vehicle-mounted Ethernet harness transmission performance test method as described above, including a control module, a standard module and a decision module, wherein the control module, the standard module and the decision module are communicatively connected, wherein:

[0089] The control module is used to control a combination of multiple environmental conditions to test the wiring harness to be tested and obtain the measured transmission performance parameters;

[0090] The standard module is used to input a combination of multiple environmental conditions into the test standard model to obtain standard transmission performance parameters;

[0091] The decision module is used to compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standard.

[0092] Furthermore, the control module tests the wiring harness to be tested three times in total. When the variance of the three test results is less than a preset variance, the average value is taken as the result of the three tests; when the variance of the three test results is greater than or equal to the preset variance, the wiring harness to be tested is determined to be unqualified.

[0093] In this embodiment, the test is divided into two situations, and the judgment is mainly made in combination with the concept of variance.

[0094] First of all, three tests are conducted to improve the reliability and consistency of the results. Through multiple measurements, accidental errors or abnormal results caused by specific conditions can be eliminated. Variance is an indicator used to measure the degree of dispersion of a set of data. When the variance of the three test results is less than the preset variance, it means that the three test results are relatively close, indicating that the test process is consistent and reliable. In this case, the average of the three test results can be taken as the final result, and this average value can better represent the true performance of the wiring harness to be tested. On the contrary, when the variance of the three test results is greater than or equal to the preset variance, it means that there are obvious differences between the test results and the test is not credible. At this time, it may be that the wiring harness has defects in performance or the test conditions are inconsistent, resulting in large fluctuations in the results. According to the set standards, the wiring harness to be tested will be judged as unqualified in this case to ensure that the quality of the product meets the expected standards.

[0095] Furthermore, the decision module also includes a result output module, which is used to visually display the measured transmission performance parameters that do not meet the unified standard when the wiring harness to be tested does not meet the unified standard.

[0096] In this embodiment, the function of the result output module in the decision module is mainly to provide performance evaluation feedback of the wiring harness to be tested. When the performance parameters of the wiring harness to be tested do not meet the unified standards, the module will present the test results in a visual manner. This visual display method allows users to more intuitively understand the specific situation of the transmission performance parameters of the wiring harness in actual testing.

[0097] Specifically, the result output module will display unqualified performance parameters in the form of charts, dashboards, etc. These visualization tools can help users quickly identify which parameters do not meet the expected standards and further analyze the possible reasons. Through clear graphics or data, users can more easily troubleshoot and analyze, and improve the efficiency of handling unqualified products.

[0098] In addition, the visualization function of the result output module can also be used to generate reports to facilitate the recording and archiving of test data. This helps with subsequent quality control and improvement measures, making the inspection in the production process more efficient and accurate. In general, the decision module combined with the result output module not only improves the transparency of performance testing, but also provides strong support for quality management.

[0099] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for testing the transmission performance of an in-vehicle Ethernet harness, characterized in that: The following steps are involved: S1. Obtaining transmission performance parameters of independent communication channels of vehicle Ethernet harnesses through a multi-port vector network analyzer; the transmission performance parameters include characteristic impedance, insertion loss, return loss, longitudinal transformation loss, and longitudinal conversion transmission loss; S2. Control the combination of multiple environmental conditions and record the changes of the transmission performance parameters; S3. Acquire the vehicle Ethernet harness test data that works well in steps S1-S2, and construct a test standard model; the test data includes environmental conditions and transmission performance parameters; the test standard model uses environmental conditions as input and transmission performance parameters as standard output, and is used to measure standard transmission performance parameters under different environmental conditions; the test standard model is configured as a random forest model, and the random forest model uses environmental conditions as features and transmission performance parameters as labels; During the model training process, the data set samples were divided into five parts, four of which were used as training sets and one as prediction set. The prediction performance of the model was verified by crossing five times. S4. Obtaining the measured transmission performance parameters of the wiring harness to be tested under various combinations of environmental conditions, and inputting the various combinations of environmental conditions into the test standard model to output corresponding standard transmission performance parameters; S5. Compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standard, including the following steps: Calculate the transmission performance difference between the measured transmission performance parameter and the standard transmission performance parameter; Divide the transmission performance difference by the standard transmission performance parameter to obtain the relative deviation of the transmission performance; When the relative deviation of the transmission performance exceeds a set threshold, it is determined that the wiring harness does not meet the unified standard; When the relative deviation of the transmission performance does not exceed a set threshold, it is determined that the wiring harness meets the unified standard.

2. A method for testing transmission performance of an in-vehicle Ethernet harness according to claim 1, characterized in that: The relative deviation of the transmission performance is calculated as follows: ， In the formula, X r Indicates the relative deviation of transmission performance; X s Indicates the measured transmission performance parameters; X b Indicates standard transmission performance parameters.

3. The method for testing the transmission performance of an in-vehicle Ethernet harness according to claim 1, characterized in that: The characteristic impedance is used to describe the relationship between voltage and current in the wire harness, and is determined by measuring the reflection coefficient and the known length and material properties of the wire harness; The insertion loss refers to the loss of a signal when it passes through a wiring harness, and is measured by comparing the strength of the input signal with the output signal; The return loss is used to reflect the reflection of the signal due to impedance mismatch. It is calculated by first sending a signal through the vector detector and then measuring the strength of the reflected signal. The longitudinal conversion loss is used to measure the signal loss when the wire harness is converted between different connections or connectors. The loss between the connection points is evaluated by connecting the wire harness to different adapters or modules and measuring the signal strength change using a vector detector. The longitudinal conversion transmission loss is the penetration loss of the signal between different channels or connection components, and is determined by comparing the signal strength after direct connection and passing through the connection component through a vector detector.

4. The method for testing the transmission performance of an in-vehicle Ethernet harness according to claim 1, characterized in that: The controlling the combination of multiple environmental conditions and recording the changes of the transmission performance parameters comprises the following steps: S21. Use an orthogonal approach to set a combination of multiple environmental conditions; S22. Test the wiring harness under each combination of environmental conditions; S23. According to the test results, record the transmission performance parameters under different combinations of environmental conditions.

5. The method for testing the transmission performance of an in-vehicle Ethernet harness according to claim 1, characterized in that: The environmental conditions include temperature, humidity and vibration levels, where: The temperature is set at different temperature levels using a temperature control box to ensure that the wiring harness is within the required temperature range during testing; The humidity is adjusted by using a humidifier, and the process is monitored and controlled in real time by using sensors; According to the vibration degree, the test device is placed on a vibration table and different vibration frequencies and amplitudes are set as needed.

6. A vehicle Ethernet harness transmission performance test system, characterized in that: A vehicle Ethernet harness transmission performance test method as described in any one of claims 1 to 5, comprising a control module, a standard module and a decision module, wherein the control module, the standard module and the decision module are communicatively connected, wherein: The control module is used to control a combination of multiple environmental conditions to test the wiring harness to be tested and obtain the measured transmission performance parameters; The standard module is used to input a combination of multiple environmental conditions into the test standard model to obtain standard transmission performance parameters; The decision module is used to compare the measured transmission performance parameters with the standard transmission performance parameters to determine whether the wiring harness to be tested meets the unified standard.

7. The vehicle-mounted Ethernet harness transmission performance test system according to claim 6, characterized in that: The control module tests the wiring harness to be tested for a total of three tests, and when the variance of the three test results is less than a preset variance, an average value is taken as the result of the three tests; When the variance of the three test results is greater than or equal to the preset variance, the wiring harness to be tested is determined to be unqualified.

8. The vehicle-mounted Ethernet harness transmission performance test system according to claim 6, characterized in that: The decision module also includes a result output module, which is used to visually display the measured transmission performance parameters that do not meet the unified standard when the wiring harness to be tested does not meet the unified standard.

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