Method for testing signal of electric automobile

Abstract

The invention discloses a method for testing signals of an electric automobile, and relates to the technical field of signal testing of the electric automobile, the electric automobile comprises a signal source and vehicle-mounted equipment, and the method for testing the signals of the electric automobile comprises the steps that a test circuit model system for signal transmission of the electric automobile is constructed; acquiring an output signal of the signal source and a real-time signal at the vehicle-mounted equipment; and determining whether the signal is complete or not according to the output signal of the signal source, the real-time signal at the vehicle-mounted equipment, the measurement and calculation result of the test circuit model system and the corresponding standard value. According to the invention, the signal integrity of the electric vehicle can be tested more easily and quickly.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a method for testing signals of electric vehicles. Background Art

[0002] The rapid development of automotive electronics technology has led to increasingly higher frequencies and faster speeds for onboard electronic systems. This is particularly true for the smart cockpits and intelligent driving systems of new energy electric vehicles. The quality of these systems directly impacts driving safety and the user's perception of vehicle performance. The signal quality of the wiring harnesses and connectors used to transmit these signals directly impacts their performance, making signal integrity testing of these two systems particularly important.

[0003] Signal integrity testing is generally performed on PCBs (Printed Circuit Boards) and transmission lines. However, smart cockpits and smart driving are composed of multiple systems and multiple links. Traditional signal integrity testing is not suitable for system, integration, and automotive-level testing.

[0004] Existing signal integrity testing relies on operators using oscilloscopes to measure, integrate, and analyze relevant data. However, for complex automotive electronic systems, due to the large number of interconnected signals, comprehensive signal integrity testing takes a long time. This is especially true when conducting long-term stability tests, which can affect product R&D and production progress.

[0005] Therefore, how to test the signal integrity of electric vehicles more easily and quickly is an urgent problem that needs to be solved. Summary of the Invention

[0006] The main purpose of this application is to provide a method for testing the signal of an electric vehicle, aiming to solve the technical problem of how to easily and quickly test the signal integrity of an electric vehicle.

[0007] To achieve the above-mentioned purpose, the present application proposes a method for testing signals of an electric vehicle, wherein the electric vehicle includes a signal source and an on-board device. The method for testing signals of the electric vehicle includes:

[0008] Construct a test circuit model system for signal transmission in electric vehicles;

[0009] Obtain the output signal of the signal source and the real-time signal of the on-board equipment;

[0010] Whether the signal is complete is determined based on the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system and the corresponding standard value.

[0011] In one embodiment, the signal source includes a power supply, and the vehicle-mounted device includes a controller and an actuator;

[0012] The steps of obtaining the output signal of the signal source and the real-time signal at the vehicle-mounted device include:

[0013] After the time domain interference voltage U0(t) is input to the power supply end, the time domain voltage U(t) of the power supply is obtained, and the time domain voltage U1(t) of the controller composite voltage coupled with the time domain interference voltage and the time domain voltage U2(t) of the actuator composite voltage are obtained;

[0014] The step of determining whether the signal is complete according to the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system, and the corresponding standard value includes:

[0015] Based on the expressions U1(t)=a U(t)+b(U0(t)) and U2(t)=c U(t)+d(U0(t)) constructed by the test circuit model system, the values ​​of a, b, c, and d are calculated and compared with the corresponding standard values ​​to determine whether the signal is complete.

[0016] In one embodiment, after a time-domain interference voltage U0(t) is inputted at a power supply end, before the step of obtaining the time-domain voltage U(t) of the power supply, and obtaining the time-domain voltage U1(t) of the controller synthesized voltage coupled with the time-domain interference voltage and the time-domain voltage U2(t) of the actuator synthesized voltage, the method further includes:

[0017] Obtain the ripple current and ripple voltage of the power supply and on-board equipment;

[0018] The obtained ripple current and ripple voltage of the power supply and the on-board equipment are compared with the standard values ​​of the corresponding ripple current and ripple voltage to determine whether there is any abnormality in the corresponding test part.

[0019] In one embodiment, the power supply is directly electrically connected to the actuator to directly power the actuator;

[0020] The steps to obtain the ripple current and ripple voltage of the power supply and the vehicle-mounted equipment include:

[0021] Get the ripple current and ripple voltage of the power supply and actuator; or,

[0022] Obtain the ripple current and ripple voltage of power supplies, controllers, and actuators.

[0023] In one embodiment, after a time-domain interference voltage U0(t) is inputted at a power supply end, before the step of obtaining the time-domain voltage U(t) of the power supply, and obtaining the time-domain voltage U1(t) of the controller synthesized voltage coupled with the time-domain interference voltage and the time-domain voltage U2(t) of the actuator synthesized voltage, the method further includes:

[0024] Obtain the output voltage of the power supply, the load voltage and the current of the relevant links of the electric vehicle;

[0025] In the test circuit model system, the equivalent impedance of the electric vehicle-related test link is calculated and compared with the corresponding theoretical line resistance to determine whether there is any abnormality in the corresponding test part.

[0026] In one embodiment, the vehicle-mounted device includes an actuator;

[0027] The steps of obtaining the output signal of the signal source and the real-time signal at the vehicle-mounted device include:

[0028] Acquire the output signal of the signal source and the real-time signal of the actuator at the end.

[0029] In one embodiment, the step of determining whether the signal is complete based on the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system, and the corresponding standard value includes:

[0030] Input the output signal of the signal source and the real-time signal of the actuator at the end into the test circuit model system, perform relevant calculations, and compare the calculated values ​​with the corresponding standard value range;

[0031] Determine whether the error range of the real-time signal of the end actuator is within the range of the corresponding standard value;

[0032] If so, confirm that the signal integrity meets the requirements;

[0033] If not, the real-time signal of the previous vehicle-mounted device is obtained, and it is determined whether the error range of the real-time signal of the vehicle-mounted device is within the range of the corresponding standard value.

[0034] In one embodiment, after the step of obtaining the real-time signal of the previous vehicle-mounted device and determining whether the error range of the real-time signal of the vehicle-mounted device is within the range of the corresponding standard value, the method further includes:

[0035] If so, it is determined that the signal transmission between the vehicle-mounted device and the subsequent vehicle-mounted device is incorrect;

[0036] If not, repeat this step.

[0037] In one embodiment, after the step of determining that the signal transmission between the vehicle-mounted device and the subsequent vehicle-mounted device is erroneous, the method further includes:

[0038] Obtaining real-time signals of the vehicle-mounted device and the next vehicle-mounted device;

[0039] Whether the signal is complete is determined based on the real-time signals of the vehicle-mounted device and the next vehicle-mounted device, multiple different parameters calculated by the test circuit model system, and corresponding standard values.

[0040] In one embodiment, the plurality of different parameters include a signal line reflection coefficient Γ, a signal line signal standing wave ratio VSWR, a signal line return loss RL, and a signal port insertion loss IL.

[0041] The electric vehicle signal testing method proposed in this application constructs a relevant test circuit model, then obtains a real-time signal. The real-time signal value is input into the model, and the model outputs a calculation result. The calculation result is then compared with the corresponding standard value to determine whether the relevant signal is complete. The method proposed in this application greatly improves the automation level of the signal integrity testing process and reduces the time required for signal integrity testing in electric vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 A flowchart of a first embodiment of a method for testing signals of an electric vehicle according to the present invention is provided;

[0045] Figure 2 A flow chart of a second embodiment of a method for testing signals of an electric vehicle according to the present invention;

[0046] Figure 3 A flowchart of a third embodiment of a method for testing signals of an electric vehicle according to the present application is provided;

[0047] Figure 4 A flowchart of a fourth embodiment of a method for testing signals of an electric vehicle according to the present application is provided;

[0048] Figure 5 This is a schematic diagram of the control principle of the power harness equivalent impedance test model established in the third embodiment of the present application;

[0049] Figure 6 This is a schematic diagram of a line impedance curve measured by the power harness equivalent impedance test model in the second embodiment of the present application;

[0050] Figure 7 This is a schematic diagram of the control principle of the power interference test model established in the third embodiment of the present application;

[0051] Figure 8 This is a schematic diagram of the control principle of the multi-link test model established in the fourth embodiment of the present application;

[0052] Figure 9 This is a schematic diagram of the control principle of a single-link test model established in the fourth embodiment of the present application;

[0053] Figure 10 This is a measured diagram of the limit requirements obtained by the single-link test model in the fourth embodiment of the present application.

[0054] 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 DESCRIPTION

[0055] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.

[0056] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0057] The rapid development of automotive electronics technology has led to increasingly higher frequencies and faster speeds for onboard electronic systems. This is particularly true for the smart cockpits and intelligent driving systems of new energy electric vehicles. The quality of these systems directly impacts driving safety and the user's perception of vehicle performance. The signal quality of the wiring harnesses and connectors used to transmit these signals directly impacts their performance, making signal integrity testing of these two systems particularly important.

[0058] Signal integrity testing is typically performed on printed circuit boards (PCBs) and transmission lines. However, smart cockpits and intelligent driving are comprised of multiple systems and links, making traditional signal integrity testing unsuitable for system, integration, and automotive-level testing. Existing signal integrity testing relies on operators using oscilloscopes to measure, integrate, and analyze relevant data. However, for complex automotive electronic systems, with numerous and interconnected signals, comprehensive signal integrity testing is time-consuming, especially during extended stability testing, which can impact product development and production schedules.

[0059] Therefore, how to test the signal integrity of electric vehicles more easily and quickly is an urgent problem that needs to be solved.

[0060] Based on this, the embodiment of the present application provides a method for testing the signal of an electric vehicle, referring to Figure 1 , Figure 1 This is a flow chart of a first embodiment of a method for testing signals of an electric vehicle according to the present application.

[0061] In this embodiment, the electric vehicle includes a signal source and an on-board device. The method for testing the signal of the electric vehicle includes steps S10 to S30:

[0062] Step S10, constructing a test circuit model system for signal transmission of an electric vehicle;

[0063] Step S20, obtaining the output signal of the signal source and the real-time signal of the vehicle-mounted device;

[0064] Step S30 , determining whether the signal is complete based on the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system, and the corresponding standard value.

[0065] The electric vehicle signal testing method proposed in this application constructs a relevant test circuit model, then obtains a real-time signal. The real-time signal value is input into the model, and the model outputs a calculation result. The calculation result is then compared with the corresponding standard value to determine whether the relevant signal is complete. The method proposed in this application greatly improves the automation level of the signal integrity testing process and reduces the time required for signal integrity testing in electric vehicles.

[0066] It should be noted that since there are many parts inside the electric vehicle, in order to simplify the model design, all the parts of the vehicle are divided into signal sources and on-board equipment. In addition, according to different test items, the relevant parameters and indicators of the signal source and on-board equipment are designed in advance, which can facilitate subsequent calculations.

[0067] Please refer to Figure 2 and Figure 7 In the first embodiment of the present application, the signal source includes a power supply, and the vehicle-mounted device includes a controller and an actuator; step S20 includes step A11, and step S30 includes step A12;

[0068] Step A11: After inputting the time domain interference voltage U0(t) at the power supply end, obtain the time domain voltage U(t) of the power supply, and obtain the time domain voltage U1(t) of the controller composite voltage coupled with the time domain interference voltage and the time domain voltage U2(t) of the actuator composite voltage;

[0069] Step A12, based on the expressions U1(t)=a U(t)+b(U0(t)) and U2(t)=c U(t)+d(U0(t)) constructed by the test circuit model system, calculate the values ​​of a, b, c, and d, and compare them with the corresponding standard values ​​to determine whether the signal is complete.

[0070] In this embodiment, by measuring multiple groups of real-time data U0(t), U(t), U1(t) and U2(t) and inputting them into the power harness equivalent impedance test model, the corresponding related parameters a, b, c, d values ​​can be obtained according to the expressions U1(t) = a U(t) + b(U0(t)) and U2(t) = c U(t) + d(U0(t)), and compared with the corresponding standard values. If they are within the specified error range, it is determined that the transmission integrity of the power link of this part is correct. If it is outside the specified error range, it means that there is an abnormality in the power filter (including controller power filtering and actuator filtering), and the relevant facilities need to be checked on site.

[0071] It should be noted that, in the second embodiment of the present application, before step A11, steps A111 to A112 are also included;

[0072] Step A111, obtaining the ripple current and ripple voltage of the power supply and the vehicle-mounted equipment;

[0073] In step A112, the obtained ripple current and ripple voltage of the power supply and the vehicle-mounted equipment are compared with the corresponding standard values ​​of the ripple current and ripple voltage to determine whether there is any abnormality in the corresponding test part.

[0074] It can be understood that for a circuit system, the transmission of current and voltage is the basis for implementing signal transmission. Therefore, performing steps A111 to A112 can confirm that the function of the relevant links under test to transmit relevant electrical signals is complete, thereby improving the credibility of the transmission data of subsequent detections of different signals.

[0075] It should be noted that, in an electric vehicle, there is an actuator directly connected to a power source, so in the test circuit model system of the present application, the power source is directly electrically connected to the actuator to directly power the actuator; in the second embodiment of the present application, the step A111 includes A1111;

[0076] Step A1111, obtaining the ripple current and ripple voltage of the power supply and the actuator; or,

[0077] Obtain the ripple current and ripple voltage of power supplies, controllers, and actuators.

[0078] Therefore, by establishing a model of the relevant link of the actuator directly connected to the power supply and conducting relevant tests, it is possible to confirm that the function of this part of the link in transmitting relevant electrical signals is correct. On the other hand, by establishing a complex link in which the power supply supplies power to the controller and the controller supplies power to the actuator, it is possible to confirm that the function of this part of the link in transmitting relevant electrical signals is correct. These two different links cover all links of various components in the electric vehicle, thereby obtaining more accurate test conclusions.

[0079] See also Figure 3 、 Figure 5 and Figure 6 It is understandable that, for a circuit system, in addition to confirming the transmission of current and voltage, it is also necessary to measure the impedance of the line to confirm whether the link is damaged. Therefore, in the third embodiment of the present application, steps B111 to B112 are included before step A11;

[0080] Step B111, obtaining the output voltage of the power supply, the load voltage, and the current of the relevant links of the electric vehicle;

[0081] Step B112: Calculate the equivalent impedance of the electric vehicle-related test link in the test circuit model system and compare it with the corresponding theoretical line resistance to determine whether there is an abnormality in the corresponding test part.

[0082] It is understandable that for the circuit system, ensuring that the system resistance is within the theoretical range is the basis for subsequent signal integrity testing. Therefore, a power harness equivalent impedance test model is established. According to steps B111 to B112, it can be confirmed whether there are abnormal values ​​in the equivalent impedance of the circuit model system. If abnormal values ​​appear, it is necessary to check the power supply, connector and related wiring harness.

[0083] See also Figure 4 , in the fourth embodiment of the present application, the vehicle-mounted device includes an actuator; step S20 includes step C11;

[0084] Step C11: Acquire the output signal of the signal source and the real-time signal of the actuator at the end.

[0085] It should be noted that, in this embodiment, the signal source may be a power supply, a controller, or an actuator, and the actuator at the end is the last actuator of the relevant test link.

[0086] See also Figure 8 , in the fourth embodiment of the present application, step S30 includes steps C21 to C24;

[0087] Step C21: Input the output signal of the signal source and the real-time signal of the actuator at the end into the test circuit model system, perform relevant calculations, and compare the calculated value with the corresponding standard value range;

[0088] Step C22, determining whether the error range of the real-time signal of the end actuator is within the range of the corresponding standard value;

[0089] Step C23: If yes, determine that the signal integrity meets the requirements;

[0090] Step C24: If not, obtain the real-time signal of the previous vehicle-mounted device and determine whether the error range of the real-time signal of the vehicle-mounted device is within the range of the corresponding standard value.

[0091] It is understandable that in order to determine the signal integrity of the entire vehicle, it is necessary to expand the measurement scope to all test links of the entire vehicle, that is, to establish a multi-link test model. Step C11 obtains the real-time signals of the power supply and the actuator at the end. In step C21, the collected real-time signals are input into the multi-link test model and relevant calculations are performed. If the calculated value is within the range of the corresponding standard value, it indicates that the signal transmission function from the power supply to the actuator at the end (that is, all links of the entire vehicle) is intact. If the calculated value is outside the range of the corresponding standard value, it indicates that there is a problem with the signal transmission function of at least one part of the entire link of the vehicle, and then step C24 is performed. For details, please refer to Figure 8 For example, the measurement range of step C21 is between the power supply and the actuator at the end (that is, the on-board device n). If the measured value is within the range of the corresponding standard value, it indicates that the signal transmission function of the link from the power supply to the actuator at the end is intact. If the measured value is outside the range of the corresponding standard value, it indicates that there is a problem with the signal transmission function of at least one part between the power supply and the actuator at the end, and then step C24 is performed. At this time, the real-time signal of the previous on-board device (that is, on-board device n-1) from the power supply to the actuator at the end is measured and it is determined whether the error range of the real-time signal of the on-board device is within the range of the corresponding standard value.

[0092] It is understood that in order to locate the part where signal transmission is incomplete, the measurement range is narrowed down from the whole vehicle range, and the measurement is performed again. At the same time, the measurement is performed in the relevant link test model and compared with the corresponding standard value. If the measurement result after the narrowed range meets the standard, it can be determined that the part where signal transmission is incomplete is within the range not covered by the narrowed range test. Therefore, after step C24, steps C241 to C242 are also included;

[0093] Step C241: If yes, it is determined that there is an error in the signal transmission between the vehicle-mounted device and the next vehicle-mounted device;

[0094] Step C242, if not, repeat this step.

[0095] Through steps C241 to C242, the location where the signal transmission is incomplete can be determined, and the interval can be narrowed down to between two vehicle-mounted devices. Specifically, the error range of the measured value of the real-time signal of the current vehicle-mounted device (for example, vehicle-mounted device n-1) is within the range of the corresponding standard value, that is, the signal transmission function between the power supply and the previous vehicle-mounted device (vehicle-mounted device n-1) is correct. The conclusion drawn from step C24 (there is a problem with the signal transmission function between the power supply and vehicle-mounted device n) can be determined that the location where the signal transmission is incomplete is between the vehicle-mounted device (vehicle-mounted device n-1) and the next vehicle-mounted device (vehicle-mounted device n) of the vehicle-mounted device (vehicle-mounted device n-1) on the relevant link, that is, the specific location where the signal transmission is incomplete is determined.

[0096] It is understandable that after determining the location where the signal transmission is incomplete (taking the area between the vehicle-mounted device n-1 and the vehicle-mounted device n as an example), it is necessary to specifically determine the cause of the incomplete signal transmission. Therefore, after step C241, steps C2411 to C2412 are also included.

[0097] Step C2411, obtaining real-time signals of the vehicle-mounted device and the next vehicle-mounted device;

[0098] Step C2412, determining whether the signal is complete based on the real-time signals of the vehicle-mounted device and the next vehicle-mounted device, multiple different parameters calculated by the test circuit model system, and corresponding standard values.

[0099] It should be noted that this application does not make any specific limitations on the multiple different parameters, and the specific requirements shall be based on actual operation. Specifically, in the fourth embodiment of this application, the multiple different parameters include the signal line reflection coefficient Γ, the signal line signal standing wave ratio VSWR, the signal line return loss RL and the signal port insertion loss IL.

[0100] See also Figure 9 and Figure 10 , establish a single link test model, take the part between vehicle-mounted device n-1 and vehicle-mounted device n as an example, and obtain the output voltage of the vehicle-mounted device (vehicle-mounted device n-1) (that is, the input voltage V in ), obtain the reflected voltage V of the vehicle-mounted device n r , output voltage V out , the corresponding signal value is reflected according to the voltage value so that the signal transmission effect can be seen more intuitively.

[0101] According to the expression, the signal line reflection coefficient Γ=V r / Vin , the signal line reflection coefficient Γ can be calculated and compared with the corresponding standard value. If it is outside the range of the corresponding standard value, it means that the circuit connection relationship is abnormal, and there may be poor contact or even an open circuit or disconnection in the electric vehicle circuit system.

[0102] According to the expression, the signal line signal standing wave ratio VSWR=(1+Γ) / (1-Γ), that is, VSWR=(V in +V r ) / (V in -V r ), the signal line signal standing wave ratio VSWR can be calculated and compared with the corresponding standard value. If it is outside the range of the corresponding standard value, it means that the system connection and impedance matching of the electric vehicle are abnormal, and it is necessary to check the internal and external interference of the electric vehicle system.

[0103] According to the expression, the signal line return loss RL=-20lg(Γ), that is, RL=-20lg(V r / V in ), the signal line return loss RL can be calculated and compared with the corresponding standard value. If it is outside the range of the corresponding standard value, it means that the matching and connection of the electric vehicle system are abnormal.

[0104] According to the expression, the signal port insertion loss IL=-20lg(V out / V in ), the signal port insertion loss IL can be calculated and compared with the corresponding standard value. If it is outside the range of the corresponding standard value, it means that there is an abnormality in the connection between each controller and the connecting line.

[0105] The above description is only part of the embodiments of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for testing signals of an electric vehicle, characterized in that: The electric vehicle includes a signal source and an on-board device, and the method for testing the signal of the electric vehicle includes: Construct a test circuit model system for signal transmission in electric vehicles; Obtain the output signal of the signal source and the real-time signal of the on-board equipment; Whether the signal is complete is determined based on the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system and the corresponding standard value.

2. The method for testing the signal of an electric vehicle according to claim 1, wherein: The signal source includes a power supply, and the vehicle-mounted device includes a controller and an actuator; The steps of obtaining the output signal of the signal source and the real-time signal at the vehicle-mounted device include: After the time domain interference voltage U0(t) is input to the power supply end, the time domain voltage U(t) of the power supply is obtained, and the time domain voltage U1(t) of the controller composite voltage coupled with the time domain interference voltage and the time domain voltage U2(t) of the actuator composite voltage are obtained; The step of determining whether the signal is complete according to the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system, and the corresponding standard value includes: Based on the expressions U1(t)=a U(t)+b(U0(t)) and U2(t)=c U(t)+d(U0(t)) constructed by the test circuit model system, the values ​​of a, b, c, and d are calculated and compared with the corresponding standard values ​​to determine whether the signal is complete.

3. The method for testing the signal of an electric vehicle according to claim 2, wherein: After inputting the time domain interference voltage U0(t) at the power supply end, before the step of obtaining the time domain voltage U(t) of the power supply, and obtaining the time domain voltage U1(t) of the controller composite voltage coupled with the time domain interference voltage and the time domain voltage U2(t) of the actuator composite voltage, the method further includes: Obtain the ripple current and ripple voltage of the power supply and on-board equipment; The obtained ripple current and ripple voltage of the power supply and the on-board equipment are compared with the standard values ​​of the corresponding ripple current and ripple voltage to determine whether there is any abnormality in the corresponding test part.

4. The method for testing the signal of an electric vehicle according to claim 3, wherein: The power supply is directly electrically connected to the actuator to directly supply power to the actuator; The steps to obtain the ripple current and ripple voltage of the power supply and the vehicle-mounted equipment include: Get the ripple current and ripple voltage of the power supply and actuator; or, Obtain the ripple current and ripple voltage of power supplies, controllers, and actuators.

5. The method for testing the signal of an electric vehicle according to claim 2, wherein: After inputting the time domain interference voltage U0(t) at the power supply end, before the step of obtaining the time domain voltage U(t) of the power supply, and obtaining the time domain voltage U1(t) of the controller composite voltage coupled with the time domain interference voltage and the time domain voltage U2(t) of the actuator composite voltage, the method further includes: Obtain the output voltage of the power supply, the load voltage and the current of the relevant links of the electric vehicle; In the test circuit model system, the equivalent impedance of the electric vehicle-related test link is calculated and compared with the corresponding theoretical line resistance to determine whether there is any abnormality in the corresponding test part.

6. The method for testing signals of an electric vehicle according to claim 1, wherein: The vehicle-mounted device includes an actuator; The steps of obtaining the output signal of the signal source and the real-time signal at the vehicle-mounted device include: Acquire the output signal of the signal source and the real-time signal of the actuator at the end.

7. The method for testing the signal of an electric vehicle according to claim 6, wherein: The step of determining whether the signal is complete according to the output signal of the signal source, the real-time signal at the vehicle-mounted device, the result calculated by the test circuit model system, and the corresponding standard value includes: Input the output signal of the signal source and the real-time signal of the actuator at the end into the test circuit model system, perform relevant calculations, and compare the calculated values ​​with the corresponding standard value range; Determine whether the error range of the real-time signal of the end actuator is within the range of the corresponding standard value; If so, confirm that the signal integrity meets the requirements; If not, the real-time signal of the previous vehicle-mounted device is obtained, and it is determined whether the error range of the real-time signal of the vehicle-mounted device is within the range of the corresponding standard value.

8. The method for testing signals of an electric vehicle according to claim 7, wherein: After the steps of obtaining the real-time signal of the previous vehicle-mounted device and determining whether the error range of the real-time signal of the vehicle-mounted device is within the range of the corresponding standard value, the method further includes: If so, it is determined that the signal transmission between the vehicle-mounted device and the subsequent vehicle-mounted device is incorrect; If not, repeat this step.

9. The method for testing a signal of an electric vehicle according to claim 8, wherein: After determining that the signal transmission between the vehicle-mounted device and the subsequent vehicle-mounted device is erroneous, the method further includes: Obtaining real-time signals of the vehicle-mounted device and the next vehicle-mounted device; Whether the signal is complete is determined based on the real-time signals of the vehicle-mounted device and the next vehicle-mounted device, a plurality of different parameters measured by the test circuit model system, and corresponding standard values.

10. The method for testing signals of an electric vehicle according to claim 9, wherein: The multiple different parameters include a signal line reflection coefficient Γ, a signal line signal standing wave ratio VSWR, a signal line return loss RL, and a signal port insertion loss IL.

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