In-vehicle wiring harness coupling immunity test system

Abstract

This invention is a divisional application, the original application number is 202311266637.0, the application date is September 27, 2023, and the name is a method for testing the coupling and anti-interference of wire harnesses in a complex electromagnetic environment in a vehicle. The present invention discloses a system for testing the coupling and anti-interference of wire harnesses in a vehicle, including signal acquisition, signal processing, signal generator, system calibration, test execution and result judgment. The wiring harnesses of the whole vehicle are classified, collected and screened out by region, and the data with the largest electromagnetic noise width value in the wiring harnesses in the region are used for the coupling and anti-interference test of wire harnesses. The electromagnetic wave signals after calibration are subjected to the coupling and anti-interference test of wire harnesses and the results are judged. The system injects the electromagnetic signal of the real vehicle into the wiring harness through a coupling clamp, simulates the coupling between the wiring harnesses of the real vehicle, and evaluates the crosstalk risk of the wiring harnesses under the same conditions of the real vehicle through the coupling and anti-interference test between the wiring harnesses.

Description

[0001] This invention is a divisional application, the original application number is 202311266637.0, the application date is September 27, 2023, and its name is a method for testing the coupling immunity of wiring harnesses under complex electromagnetic environment in a vehicle. Technical Field

[0002] The present invention relates to the technical field of electric disturbance testing caused by coupling of electrical / electronic components of road vehicles, and in particular to a method for testing the anti-disturbance of coupling between wiring harnesses under a complex electromagnetic environment in a vehicle. Background Art

[0003] Vehicles generate electrical and radio frequency disturbances during normal operation. These disturbance signals have a wide frequency range and can affect on-board electrical / electronic components and systems through conduction, coupling or radiation. Currently, most vehicles are equipped with electrical / electronic components and systems for control, monitoring and display functions, which are subject to disturbances generated by the vehicle's own electrical / electronic systems, causing performance degradation or even permanent damage.

[0004] "Test Methods for Electrical Disturbance Caused by Conduction and Coupling of Electrical / Electronic Components of Road Vehicles" (GB / T21437) specifies the test methods for conducted emission and immunity of electrical transients along power lines, immunity to electrical transients coupled to non-power lines, and conduction and immunity of electrical transients along high-voltage shielded power lines. Among them, it is recommended to use a test pulse generator to conduct bench tests to evaluate the immunity of components to transients in power lines or data lines (see GB / T21437.1-2021, GB / T21437.2-2021, GB / T21437.3-2021 for details). Because some components are particularly sensitive to some characteristics of electrical disturbances such as pulse repetition rate, pulse width, and time relative to other signals, and the recommended method does not cover all forms of transients generated in the vehicle, it has limitations.

[0005] "Test Method for Immunity of Electrical / Electronic Components of Road Vehicles to Narrowband Radiated Electromagnetic Energy" (GB / T33014) specifies the large current injection (BCI) method, which is a method of using a current injection probe to directly couple the disturbance signal to the harness for immunity testing. The injection probe is a current transformer, through which the harness of the device under test (DUT) passes, and the immunity test is performed by changing the test severity level and the frequency of the induced disturbance.

[0006] The ability of vehicles and electrical and electronic systems / components to work normally in the vehicle's electromagnetic environment without affecting the normal operation of other vehicles, systems / components is called vehicle electromagnetic compatibility (EMC). EMC design and EMC testing complement each other, and the quality of EMC design needs to be measured through EMC testing. During the entire process of product EMC design and development, EMC compatibility prediction and evaluation can detect possible electromagnetic interference early and take necessary suppression and protection measures to ensure the electromagnetic compatibility of the system.

[0007] The above test methods (transient immunity test method and bulk current injection (BCI) method) have the following deficiencies:

[0008] 1. The test pulse generator used in the transient immunity test is only a typical pulse form, which fails to cover various transient pulses that may appear on the vehicle. That is, the pulse waveform is fixed and different from the interference waveform under the complex electromagnetic environment of the whole vehicle, and cannot reflect the inter-system interference problems that may occur in the actual use of the whole vehicle.

[0009] 2. The interference signal injected by the bulk current injection (BCI) method is a fixed modulated signal, and the current injection is only performed at 100KHz~400MHz. The interference signal frequency and interference signal modulation cannot fully reflect the in-vehicle noise under the complex electromagnetic environment of the whole vehicle.

[0010] 3. The above method requires special equipment and environment, and is tested in the laboratory. The product verification is not sufficient and cannot reflect the true electromagnetic anti-interference performance of the product, which increases the testing cost. The whole vehicle may have the risk of potential coupling interference between wiring harnesses.

[0011] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0012] The main purpose of the present invention is to solve the above technical problems.

[0013] To achieve the above object, the present invention provides an in-vehicle wiring harness coupling anti-disturbance test system, comprising:

[0014] Signal acquisition: Classify the wiring harness of the vehicle by area and collect electromagnetic signals according to the vehicle status;

[0015] Signal processing: The collected electromagnetic signals are sorted and the data with the largest electromagnetic noise width value in the wiring harness in the area is selected for the inter-wiring harness coupling anti-interference test; wherein, the data with the largest electromagnetic noise width value in the wiring harness in the area includes:

[0016] For electromagnetic signals with similar waveforms, retain the signal data with the highest intensity, and for electromagnetic signals with inconsistent waveforms, save them as candidate electromagnetic signals; or

[0017] For electromagnetic signals with similar waveforms, retain the signal data with the largest width, and for electromagnetic signals with inconsistent waveforms, save them as candidate electromagnetic signals; or

[0018] For electromagnetic signals with similar waveforms, the signal data with the largest frequency range is retained, and electromagnetic signals with inconsistent waveforms are saved as alternative electromagnetic signals;

[0019] Signal generator: Input the electromagnetic signal for the harness coupling immunity test obtained in the previous step into the signal generator for pre-test calibration;

[0020] System calibration: sort out the electromagnetic signal waveforms collected from the actual vehicle and select the electromagnetic signals for the harness coupling anti-interference test;

[0021] Test execution: The electromagnetic wave signal after calibration is subjected to the inter-harness coupling anti-interference test;

[0022] Result determination: Determine the result based on the harness coupling immunity test in the previous step.

[0023] Preferably, the signal acquisition includes a spectrum analyzer and a current clamp; the spectrum analyzer is electrically connected to the current clamp, and the current clamp is used to collect electromagnetic signals of the test harness in the vehicle.

[0024] Preferably, the wiring harness of the whole vehicle is classified by area, including: wiring harness in the engine compartment, wiring harness in the passenger compartment, door wiring harness, high-voltage wiring harness, body wiring harness, ceiling wiring harness, electric power steering wiring harness, engine ground wire, floor wiring harness, instrument panel wiring harness, and battery wiring harness.

[0025] Preferably, the vehicle state includes a power-on state, a constant speed running state, a vehicle acceleration state and a vehicle deceleration state.

[0026] Preferably, the system calibration comprises a coupling clamp, wherein the coupling clamp is composed of a plurality of magnetic rings.

[0027] Preferably, the coupling clamp is used for testing low-frequency coupling.

[0028] Preferably, the system calibration comprises a coupling clamp, wherein the coupling clamp is composed of a plurality of capacitors.

[0029] Preferably, the coupling clamp is used for testing high-frequency coupling.

[0030] The present application discloses a system for testing the coupling and interference immunity between wiring harnesses in a vehicle, including signal acquisition, signal processing, a signal generator, system calibration, test execution and result determination. The wiring harnesses of the entire vehicle are classified by region and electromagnetic signals are acquired according to the vehicle status. The electromagnetic signals used for the coupling and interference immunity test between wiring harnesses are sorted and screened out. The system for testing the coupling and interference immunity between wiring harnesses in a specific complex electromagnetic environment in the vehicle is composed of a signal generator, a coupling clamp and the like. The signal generator inputs the electromagnetic signal collected from the actual vehicle into the signal coupling clamp, and finally the electromagnetic signal of the actual vehicle is injected into the wiring harness through the coupling clamp to simulate the coupling between wiring harnesses of the actual vehicle. The crosstalk risk of the wiring harnesses under the same conditions of the actual vehicle is evaluated through the coupling and interference immunity test between wiring harnesses. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a working flow chart of the inter-harness coupling anti-interference testing method involved in the embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram of an electromagnetic signal acquisition system involved in an embodiment of the present invention;

[0033] Figure 3 It is a calibration principle diagram of the inter-harness coupling anti-disturbance test system involved in the embodiment of the present invention;

[0034] Figure 4 1 is a diagram of a wiring harness coupling anti-interference test system according to an embodiment of the present invention;

[0035] Reference Numbers and Names

[0036] 1. Signal acquisition; 2. Signal processing; 3. Signal generator; 4. System calibration; 5. Test execution; 6. Result determination; 7. Spectrum analyzer / oscilloscope; 8. Current clamp; 9. Test harness;

[0037] 41. PC computer; 42. Signal generator; 43. Coupling clamp; 44. Resistor; 45. Oscilloscope or device under test (DUT); 46. Power supply.

[0038] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0040] In order to more clearly understand the technical solutions and embodiments of the present application, the terms that may need to be understood are now explained.

[0041] Vehicle Electromagnetic Compatibility (EMC): The ability of a vehicle, electrical and electronic systems / components to operate normally in the vehicle's electromagnetic environment without affecting the normal operation of other vehicles, systems / components.

[0042] Capacitive Coupling Clamp (CCC): A special clamp that capacitively couples fast transient test pulses to the signal line under test without making electrical connections to the circuit terminals or any other part of the device under test.

[0043] Direct Capacitive Coupling (DCC): A method of coupling fast and slow transient test pulses into the signal lines of the device under test using discrete, non-polarized capacitors.

[0044] Inductive Coupling Clamp (ICC): A probe used for high current injection that couples slow transient test pulses to the signal line under test without making electrical connection to the circuit terminals or any other part of the device under test.

[0045] Coupling: The electromagnetic phenomenon in which electrical circuits interact with each other, transferring energy from one circuit to another.

[0046] Electromagnetic radiation: An electromagnetic phenomenon in which electromagnetic energy is emitted from a source into space and / or propagates in space in the form of electromagnetic waves.

[0047] Transient: A physical quantity or phenomenon that changes between two adjacent stable states and the change time is smaller than the time scale of interest. Used to describe a single pulse or burst.

[0048] Device Under Test (DUT): The electrical / electronic device under test.

[0049] Artificial network: A device that is connected in series to the power line of the device under test, provides a specified load impedance for measuring the interference voltage within a given frequency range and isolates the device under test from the power supply.

[0050] For detailed technical terms and definitions of electromagnetic compatibility, please refer to "Electromagnetic Compatibility Terminology for Road Vehicles" (GB / T29259).

[0051] The present invention provides a method for testing the interference immunity of coupling between wiring harnesses under a complex electromagnetic environment in a vehicle, comprising the following steps:

[0052] S101, classifying the wiring harnesses of the entire vehicle by area and collecting electromagnetic signals according to the vehicle status.

[0053] Vehicle wiring harnesses are mostly copper multi-core soft wires wrapped with insulating materials, and the current of wiring harnesses in different areas is different. For example, the wiring harnesses of the whole vehicle are classified by area and named as: engine compartment wiring harness (EH), passenger compartment wiring harness (WH), door wiring harness (DH), high-voltage wiring harness (HV), body wiring harness (BH), roof wiring harness (RH), electric power steering wiring harness (EPH), engine grounding wire (EGH), floor wiring harness (UH), instrument panel wiring harness (IPH), battery wiring harness (BTH)...

[0054] The vehicle status is divided into the following four states:

[0055] Mode 1: Power-on state, the generator / DCDC and the battery supply power at the same time, and the vehicle is stationary;

[0056] Mode 2: Constant speed running state, the vehicle speed is 40km / h;

[0057] Mode 3: Vehicle acceleration state: the vehicle accelerates from rest to 90 km / h;

[0058] Mode 4: Vehicle deceleration state, the vehicle gradually decreases from 90km / h and eventually stops.

[0059] Under the above vehicle status, electromagnetic signals are collected from the wiring harnesses of the whole vehicle classified by area. By simulating the scenarios during user use, a spectrum analyzer or equivalent equipment and a current clamp are used to collect electromagnetic signals from the whole vehicle. The collected electromagnetic signals include frequency range, intensity, amplitude, width and other information to ensure that the collected electromagnetic signals are authentic and reliable.

[0060] When collecting electromagnetic signals, all manually turned-on vehicle electrical appliances are turned on and in full working order, such as windshield wipers running at high speed, the radio volume at maximum, the air conditioner at maximum, all lights working, and the battery working when accelerating or decelerating. In addition, electromagnetic signals of related devices can be collected when each functional device is turned on or off.

[0061] S102, sorting the collected electromagnetic signals to select the data with the largest electromagnetic noise width value in the wiring harness in the area for the wiring harness coupling anti-interference test.

[0062] The collected electromagnetic signals are sorted to eliminate defective electromagnetic signals, such as electromagnetic signals collected by the acquisition equipment not in normal working condition. The signal data with the highest intensity is retained for electromagnetic signals with similar waveforms, and electromagnetic signals with inconsistent waveforms are saved as alternative electromagnetic signals.

[0063] Table 1 Electromagnetic signal collection table

[0064]

[0065] Note: There can be multiple measurement values ​​(signal strength). There is no order of magnitude between the values ​​of F1, F2, F3, ... Fn. The measurements are performed based on the actual application of the vehicle and the various functional systems.

[0066] Taking signal strength as an example, the noise measurement values ​​of the electromagnetic signals collected by the wiring harnesses in each area of ​​the vehicle are recorded in the format in Table 1: F1, F2, F3, ... Fn. The measurement values ​​represent the electromagnetic noise intensity on the wiring harnesses of different systems and different layout areas of the vehicle, and are used as the test value for determining the electromagnetic environment intensity. This test value is the test condition for coupling and anti-interference between the wiring harnesses of each device under test (DUT).

[0067] S103, inputting the electromagnetic signal for the harness coupling immunity test obtained in the previous step into the signal generator for pre-test calibration.

[0068] The specific contents of the pre-test calibration are: sorting out the electromagnetic signal waveforms collected from the actual vehicle to select the electromagnetic signals for the wiring harness coupling anti-interference test, according to Figure 3 Arrange the calibration system for calibration, PC 41 is connected to signal generator 42, one end of signal generator 42 is connected to coupling clamp 43, one end of coupling clamp 43 is connected to resistor 44, and the other end of coupling clamp 43 is connected to oscilloscope 45. The test waveform (electromagnetic signal) is input to signal generator 42 through PC 41, and then input to coupling clamp 43 by signal generator 42. At the same time, oscilloscope 45 is connected to coupling clamp 43 to collect input waveform (electromagnetic signal), and compare the waveform output by PC 41 with the waveform collected by oscilloscope 45 to confirm whether the various parameters of the waveform meet the test requirements. The waveform parameters include amplitude, rising edge, period, etc.

[0069] S104, performing an inter-harness coupling anti-interference test on the calibrated electromagnetic wave signal and determining the result.

[0070] The inter-harness coupling immunity test is conducted in a shielded room. The grounding plate is a metal plate with a minimum thickness of 0.5 mm, preferably a galvanized steel plate. The minimum width of the grounding plate is 1 m and the minimum length is 2 m. It can also be set according to the GB / T 21437 method.

[0071] When making the test arrangement, the device under test (DUT) can refer to the CCC method, DCC method or ICC method in GB / T 21437.3, and use the test harness or product harness to connect the device under test (DUT) to the device connected during normal operation.

[0072] The housing grounding of the device under test (DUT) is set according to the actual installation situation of the vehicle.

[0073] The wiring harness is placed on an insulating material board 0.5m above the ground plane, and the loads connected to the wiring harness are connected to the ground plane using the shortest wire.

[0074] The distance between the device under test (DUT) and all other conductive objects is greater than 0.5m to ensure that the capacitive coupling irrelevant to the device under test (DUT) is minimized.

[0075] Exemplarily, the inter-harness coupling anti-interference test is performed using the CCC method.

[0076] The length of the harness of the device under test (DUT) passing through the CCC is 1000 (+300 / -0) mm, and the corresponding coupling clamp length is 1 m.

[0077] The wire harness passing through the CCC should be placed straight in a single layer (1-20 cables), the device under test (DUT) and the CCC are connected, and the other end of the CCC is connected to a resistor. The electromagnetic signal used for the inter-wire harness coupling immunity test generates a maximum test pulse through a signal generator. For the definition of pulses, please refer to the relevant description in GB / T 21437.2.

[0078] The signal generator is also electrically connected to a PC for editing and testing the electromagnetic signal waveform.

[0079] After all devices are connected, the results are determined based on the functional level failure definition of the device under test (DUT).

[0080] Exemplarily, the DCC method is used to perform interference testing on coupling between wiring harnesses.

[0081] The length of the device under test (DUT) harness passing through the DCC is 1700 (+300 / -0) mm.

[0082] The signal generator is connected to the capacitor via a 50Ω coaxial cable less than 0.5m long. The harness is placed on an insulating material board 50mm above the ground plane. The loads connected to the harness are connected to the ground plane using the shortest wire.

[0083] The signal generator is connected to the capacitor through a 50Ω coaxial cable, the capacitor is connected to the wiring harness through an injection line, the two ends of the wiring harness are connected to the device under test (DUT) and the simulated load respectively, and the power supply is connected to one end of the simulated load.

[0084] The signal generator is also electrically connected to a PC for editing and testing the electromagnetic signal waveform.

[0085] After all devices are connected, the results are determined based on the functional level failure definition of the device under test (DUT).

[0086] Exemplarily, the inter-harness coupling anti-interference test is performed using the ICC method.

[0087] The signal generator is connected to the ICC through a 50Ω coaxial cable, the ICC is fixed by a standard fixture, and the outside of the standard fixture is connected to the simulated load through a 50Ω coaxial cable, and a power supply is connected to one end of the simulated load.

[0088] The signal generator is also electrically connected to a PC for editing and testing the electromagnetic signal waveform.

[0089] After all devices are connected, the results are determined according to the functional level failure definition of the device under test (DUT) (see Table 2).

[0090] Table 2 Definition of functional level failure

[0091]

[0092]

[0093] The harness coupling immunity test system using the above method is shown in Figure 1 , the work flow chart of the inter-harness coupling anti-interference test method includes signal acquisition 1, signal processing 2, signal generator 3, system calibration 4, test execution 5 and result determination 6. The test system executes the above method steps, specifically, classifies the wiring harnesses of the whole vehicle by region and collects electromagnetic signals according to the vehicle status, sorts the collected electromagnetic signals and selects the data with the largest electromagnetic noise width value in the wiring harnesses in the region for inter-harness coupling anti-interference test, inputs the electromagnetic signal for inter-harness coupling anti-interference test obtained in the previous step into the signal generator for pre-test calibration, and performs inter-harness coupling anti-interference test on the electromagnetic wave signal after calibration and determines the result.

[0094] The electromagnetic signal acquisition system is shown in Figure 2 The system includes a spectrum analyzer / oscilloscope 7, a current clamp 8 and a test harness 9. The system collects electromagnetic signals of the test harness 9 in the vehicle through the current clamp 8, and classifies the harnesses of the whole vehicle by area and names them as follows: engine compartment harness (EH), passenger compartment harness (WH), door harness (DH), high voltage harness (HV), body harness (BH), roof harness (RH), electric power steering harness (EPH), engine ground wire (EGH), floor harness (UH), instrument panel harness (IPH), battery harness (BTH)…

[0095] The vehicle status is divided into the following four states:

[0096] Mode 1: Power-on state, the generator / DCDC and the battery supply power at the same time, and the vehicle is stationary;

[0097] Mode 2: Constant speed running state, the vehicle speed is 40km / h;

[0098] Mode 3: Vehicle acceleration state: the vehicle accelerates from rest to 90 km / h;

[0099] Mode 4: Vehicle deceleration state, the vehicle gradually decreases from 90km / h and eventually stops.

[0100] Under the above vehicle status, electromagnetic signals are collected from the wiring harnesses of the whole vehicle classified by area. By simulating the scenarios during user use, a spectrum analyzer or equivalent equipment and a current clamp are used to collect electromagnetic signals from the whole vehicle. The collected electromagnetic signals include frequency range, intensity, amplitude, width and other information to ensure that the collected electromagnetic signals are authentic and reliable.

[0101] When collecting electromagnetic signals, all manually turned on vehicle electrical appliances are in the on state and in maximum working condition, such as the wipers need to be at high speed, the radio volume in the car is at the maximum, the air conditioner is at the maximum state, all lights are in working condition, and the battery is in working condition for acceleration or deceleration.

[0102] The system needs to be calibrated when conducting the inter-harness coupling immunity test. Figure 3 The calibration system includes a PC 41, a signal generator 42, a coupling clamp 43, a resistor 44 and an oscilloscope 45. The signal generator 42 injects the collected and screened electromagnetic signal for testing into the test harness through the coupling clamp 43. One end of the coupling clamp 43 is connected to the resistor 44, and the other end is connected to the oscilloscope 45. The signal generator 42 is electrically connected to the PC 41, and the waveform can be edited to adjust the electromagnetic signal for testing.

[0103] After the calibration is completed, start the inter-harness coupling immunity test. Figure 4 , replace the oscilloscope with the device under test (DUT), and connect the power supply to the resistor 44. The harness coupling immunity test of the harness of the device under test (DUT) can be performed according to the method mentioned in the above embodiment, and finally the result is determined according to the functional level failure definition of the device under test (DUT).

[0104] This embodiment also discloses a coupling clamp, which at least includes a coupling clamp composed of multiple magnetic rings and a coupling clamp composed of multiple capacitors. The two coupling clamps can work simultaneously or separately. The coupling clamp composed of multiple magnetic rings is used for low-frequency coupling testing, and the coupling clamp composed of multiple capacitors is used for high-frequency coupling testing. The wiring harness of the device under test (DUT) passes through the coupling clamp composed of multiple magnetic rings or the coupling clamp composed of multiple capacitors. The collected electromagnetic signal is injected into the wiring harness of the device under test (DUT) through a signal generator to perform inter-wiring harness coupling anti-interference testing, and finally the result is determined according to the functional level failure definition of the device under test (DUT). The magnetic rings are placed in parallel, the apertures of the magnetic rings form a cavity, and there can be a certain gap between the magnetic rings; the capacitance values ​​of the capacitors are not the same.

[0105] The test system verifies the line-to-line coupled electromagnetic anti-interference performance by conducting complex in-vehicle electromagnetic noise signal coupling tests in the component EMC laboratory. It has a reliable test environment and the test results can better reflect the actual vehicle operating conditions, which helps to improve the quality of the vehicle's electromagnetic compatibility performance.

[0106] The test system adds types of signal modulation, filling the deficiencies of single modulation, constant field strength, and single waveform, making component verification more complete and test results more reliable.

[0107] The test system can perform verification and evaluation during the component testing phase, reducing the risk of functional failure of a system in the vehicle due to coupling interference between wiring harnesses, thereby improving the reliability of the vehicle.

[0108] Finally, verification is carried out in the component laboratory, which reduces the cycle and testing cost of vehicle electromagnetic compatibility performance verification and improves work efficiency.

[0109] In the above embodiment, the electromagnetic strength around the wiring harness in each area of ​​the vehicle is tested and the sorted data is applied to the component bench laboratory for verification. From the perspective of the complex electromagnetic environment in the vehicle, the coupling interference between the wiring harnesses is fully verified, reducing the risk of failure of a certain function of the vehicle and improving customer satisfaction.

[0110] According to the different operating modes of the vehicle, this method starts with the real electromagnetic noise signal collected under different loads, and converts it into a test method that can be used to verify the coupling between wiring harnesses on the component test bench. It can fully evaluate whether the vehicle has the risk of functional failure caused by potential wiring harness crosstalk.

Claims

1. The in-vehicle wiring harness coupling immunity test system is characterized by: include: Signal acquisition (1): Classify the wiring harness of the vehicle by area and collect electromagnetic signals based on the vehicle status; Signal processing (2): The collected electromagnetic signals are sorted and the data with the largest electromagnetic noise width value in the wiring harness in the area is selected for the inter-wiring harness coupling immunity test; wherein the data with the largest electromagnetic noise width value in the wiring harness in the area includes: For electromagnetic signals with similar waveforms, retain the signal data with the highest intensity, and for electromagnetic signals with inconsistent waveforms, save them as candidate electromagnetic signals; or For electromagnetic signals with similar waveforms, retain the signal data with the largest width, and for electromagnetic signals with inconsistent waveforms, save them as candidate electromagnetic signals; or For electromagnetic signals with similar waveforms, the signal data with the largest frequency range is retained, and electromagnetic signals with inconsistent waveforms are saved as alternative electromagnetic signals; Signal generator (3): input the electromagnetic signal for the inter-harness coupling immunity test obtained in the previous step into the signal generator for pre-test calibration; System calibration (4): Calibrate the electromagnetic wave signal output by the signal generator so that its parameters meet the test requirements; Test execution (5): The electromagnetic wave signal after calibration is subjected to the inter-harness coupling anti-interference test; Result determination (6): Determine the result based on the harness coupling immunity test in the previous step.

2. The in-vehicle wiring harness coupling immunity test system according to claim 1, characterized in that: The signal acquisition (1) comprises a spectrum analyzer (7) and a current clamp (8); the spectrum analyzer (7) is electrically connected to the current clamp (8), and the current clamp (8) is used to collect electromagnetic signals of a test harness (9) in a vehicle.

3. The in-vehicle wiring harness coupling immunity test system according to claim 2, characterized in that: The wiring harness of the whole vehicle is classified by area, including: wiring harness in the engine compartment, wiring harness in the passenger compartment, door wiring harness, high-voltage wiring harness, body wiring harness, ceiling wiring harness, electric power steering wiring harness, engine ground wire, floor wiring harness, instrument panel wiring harness, and battery wiring harness.

4. The in-vehicle wiring harness coupling immunity test system according to claim 3, characterized in that: The vehicle status includes a power-on status, a constant speed running status, a vehicle acceleration status, and a vehicle deceleration status.

5. The in-vehicle wiring harness coupling immunity test system according to claim 4, characterized in that: The system calibration (4) comprises a coupling clamp (43), which is composed of a plurality of magnetic rings.

6. The in-vehicle wiring harness coupling immunity test system according to claim 5, characterized in that: The coupling clamp (43) is used for testing low-frequency coupling.

7. The in-vehicle wiring harness coupling immunity test system according to claim 4, characterized in that: The system calibration (4) comprises a coupling clamp (43), which is composed of a plurality of capacitors.

8. The in-vehicle wiring harness coupling immunity test system according to claim 7, characterized in that: The coupling clamp (43) is used for testing high-frequency coupling.

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