A method and system for evaluating noise of an electric drive assembly

Abstract

The application provides a kind of electric drive assembly noise evaluation method, it is related to the field of automobile noise, the evaluation method includes: obtaining the time domain noise vibration data of electric drive assembly under the state of whole vehicle, and the first data of drive motor order noise and the second data of reduction gearbox gear order noise are obtained by processing;Obtain the time domain noise vibration data of reduction gearbox gear under the state of test bench, and the third data of reduction gearbox gear order noise is obtained by processing;The difference value of second data and third data under the same frequency is calculated, the fourth data of drive motor order noise under the state of test bench is obtained by using the first data to subtract the difference value;The fourth data under different frequencies is converted into drive motor order noise data under different speeds. The difference value of reduction gearbox gear order noise of whole vehicle and test bench is used as the intermediate quantity of conversion, and the noise result obtained by whole vehicle test can obtain the drive motor order noise under the state of test bench.

Description

Technical Field

[0001] This invention relates to the field of automotive noise, and more particularly to a method and system for evaluating the noise of an electric drive assembly. Background Technology

[0002] With the rapid development of new energy vehicles, the noise generated by their power systems has been a major concern. Currently, most domestic and international automakers use order noise sound pressure level and its vibration to describe the levels of order noise and vibration inside and outside the vehicle. Order noise can be understood as the noise generated by rotating machinery during operation, which varies in frequency with rotational speed. More precisely, the order frequency is a multiple of the rotational frequency. The industry refers to this noise, whose order response varies with rotational speed or rotational frequency, as order noise. The power system of new energy vehicles contains multiple rotating structures, resulting in a relatively rich variety of order noises. Strictly controlling the order noise of the power system of new energy vehicles is of great significance for improving the vehicle's acoustic performance and sound quality.

[0003] Currently, without motor-related control programs, it is impossible to obtain the order vibration and noise levels of the relevant electric drive assembly, and therefore it is impossible to accurately assess the order vibration and noise levels of the relevant electric drive assembly. Summary of the Invention

[0004] This invention provides a method and system for evaluating the noise of an electric drive assembly, in order to solve the technical problem of how to predict the order vibration and noise levels of a relevant electric drive assembly.

[0005] This invention provides a method for evaluating the noise of an electric drive assembly. The method includes: acquiring time-domain noise and vibration data of the electric drive assembly in a vehicle state, and processing it to obtain first data of the drive motor order noise and second data of the gearbox gear order noise; acquiring time-domain noise and vibration data of the gearbox gear in a bench test state, and processing it to obtain third data of the gearbox gear order noise; calculating the difference between the second data and the third data at the same frequency, and subtracting the difference from the first data to obtain fourth data of the drive motor order noise in the bench test state; and converting the fourth data at different frequencies into drive motor order noise data at different speeds.

[0006] Furthermore, the acquisition of time-domain noise and vibration data of the electric drive assembly in the vehicle state includes: acquiring raw time-domain data of the electric drive assembly in the vehicle state through a vibration and noise platform device; post-processing the rotational speed of the raw data to obtain the order noise data of the drive motor and the order noise data of the gearbox gear at the corresponding rotational speed; the acquisition of time-domain noise and vibration data of the gearbox gear in the test bench state includes: acquiring raw time-domain data of the gearbox gear in the test bench state through a vibration and noise platform device; post-processing the rotational speed of the raw data to obtain the order noise data of the gearbox gear at the corresponding rotational speed.

[0007] Further, the processing to obtain the first data of the drive motor order noise and the second data of the gearbox gear order noise includes: converting the drive motor order noise data at the rotational speed into the first data of the order noise at the frequency, and converting the gearbox gear order noise data at the rotational speed into the second data of the order noise at the frequency; the processing to obtain the third data of the gearbox gear order noise includes: converting the gearbox gear order noise data at the rotational speed into the third data of the order noise at the frequency.

[0008] Furthermore, the step of acquiring the time-domain raw data of the electric drive assembly in the vehicle state through the vibration and noise platform device includes: acquiring noise data at a preset distance from the drive motor and acquiring noise data at a preset distance from the gearbox gear in the vehicle state; the step of acquiring the time-domain raw data of the gearbox gear in the test bench state through the vibration and noise platform device includes: acquiring noise data at a preset distance from the gearbox gear in the test bench state.

[0009] Furthermore, the step of acquiring the time-domain raw data of the electric drive assembly in the vehicle state through the vibration and noise platform device includes: acquiring noise data from multiple monitoring points around the drive motor and acquiring noise data from multiple monitoring points around the gearbox gear in the vehicle state; the step of acquiring the time-domain raw data of the gearbox gear in the bench state through the vibration and noise platform device includes: acquiring noise data from multiple monitoring points around the gearbox gear in the bench state.

[0010] Furthermore, the acquisition of the time-domain raw data of the electric drive assembly in the vehicle state through the vibration and noise platform device also includes: acquiring the vibration data of the drive motor bearing and the gearbox input shaft bearing position in the vehicle state; the acquisition of the time-domain raw data of the gearbox gear in the bench state through the vibration and noise platform device includes: acquiring the vibration data of the gearbox input shaft bearing position in the bench state.

[0011] Furthermore, between the step of subtracting the difference from the first data to obtain the fourth data of the drive motor order noise in the test state and the step of converting the fourth data at different frequencies into drive motor order noise data at different speeds, the evaluation method further includes: changing the operating conditions of the electric drive assembly, repeating the process of acquiring the time-domain noise vibration data of the electric drive assembly in the vehicle state, and processing it to obtain the first data of the drive motor order noise and the second data of the gearbox gear order noise; acquiring the time-domain noise vibration data of the gearbox gear in the test state, and processing it to obtain the third data of the gearbox gear order noise; calculating the difference between the second data and the third data at the same frequency, and subtracting the difference from the first data to obtain the fourth data of the drive motor order noise in the test state until the number of repetitions reaches a preset threshold; and converting the fourth data at different frequencies into drive motor order noise data at different speeds.

[0012] Furthermore, changing the operating conditions of the electric drive assembly includes: the operating conditions of the electric drive assembly include at least three different throttle opening modes; the step of converting the fourth data at different frequencies into drive motor order noise data at different speeds until the number of repetitions reaches a preset threshold includes: converting the fourth data at different frequencies into drive motor order noise data at different speeds until the number of repetitions reaches three times.

[0013] This invention also provides an electric drive assembly noise assessment system. This system is used to execute the aforementioned assessment method. The system includes: an acquisition module 100, used to acquire time-domain noise and vibration data of the electric drive assembly in a vehicle state, and process it to obtain first data of the drive motor order noise and second data of the reduction gear order noise; the acquisition module 100 is further used to acquire time-domain noise and vibration data of the reduction gear in a bench test state, and process it to obtain third data of the reduction gear order noise; a processing module 200, used to calculate the difference between the second data and the third data at the same frequency, and subtract the difference from the first data to obtain fourth data of the drive motor order noise in the bench test state; the processing module 200 is further used to convert the fourth data at different frequencies into drive motor order noise data at different speeds.

[0014] Furthermore, the acquisition module 100 is also used to acquire the original time-domain data of the electric drive assembly in the vehicle state through the vibration and noise platform device; the processing module 200 is also used to post-process the rotational speed of the original data to obtain the order noise data of the drive motor and the order noise data of the gearbox gear at the corresponding rotational speed; the acquisition module 100 is also used to acquire the original time-domain data of the gearbox gear in the test bench state through the vibration and noise platform device; the processing module 200 is also used to post-process the rotational speed of the original data to obtain the order noise data of the gearbox gear at the corresponding rotational speed.

[0015] This invention provides a method for evaluating the noise of an electric drive assembly. The method includes: acquiring time-domain noise and vibration data of the electric drive assembly in a vehicle state, and processing it to obtain first data of the drive motor order noise and second data of the gearbox gear order noise; acquiring time-domain noise and vibration data of the gearbox gear in a bench test state, and processing it to obtain third data of the gearbox gear order noise; calculating the difference between the second data and the third data at the same frequency, and subtracting the difference from the first data to obtain fourth data of the drive motor order noise in the bench test state; and converting the fourth data at different frequencies into drive motor order noise data at different speeds. In the frequency domain, the difference between the order noise of the gearbox gears and the order noise of the drive motor under vehicle and bench conditions is constant. By acquiring the time-domain noise and vibration data of the gearbox gears under vehicle and bench conditions respectively, the difference in order noise between the two conditions can be obtained. This difference is used as an intermediate quantity for conversion. By acquiring the order noise data of the drive motor under vehicle conditions and using the intermediate quantity, the order noise data of the drive motor under bench conditions can be estimated. Combining the gearbox gear order noise obtained from bench measurements and the estimated drive motor order noise under bench conditions, the vibration and noise level of the entire competitor's electric drive assembly can be obtained. This effectively assists in setting reasonable noise development targets at the beginning of the forward development of the electric drive assembly and guides the project to carry out reasonable design. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a method for evaluating the noise of an electric drive assembly, as provided in an embodiment of the present invention.

[0017] Figure 2 A flowchart illustrating another method for evaluating the noise of an electric drive assembly provided in an embodiment of the present invention;

[0018] Figure 3 A flowchart illustrating another method for evaluating the noise of an electric drive assembly provided in an embodiment of the present invention;

[0019] Figure 4A flowchart illustrating another method for evaluating the noise of an electric drive assembly provided in an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of the monitoring point arrangement structure of an electric drive assembly provided in an embodiment of the present invention;

[0021] Figure 6 A flowchart illustrating another method for evaluating the noise of an electric drive assembly provided in an embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of the structure of an electric drive assembly noise assessment system provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] The specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction. For example, different combinations of specific technical features can form different embodiments and technical solutions. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this invention will not be described separately.

[0025] In the following description, the terms "first," "second," etc., are used merely to distinguish different objects and do not indicate that the objects have the sameness or relationship. It should be understood that the directional descriptions "above," "below," "outside," and "inside" refer to the orientation under normal use conditions, while "left" and "right" refer to the left and right directions shown in the corresponding diagrams, which may or may not be the left and right directions under normal use conditions.

[0026] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. The term "connection," unless otherwise specified, includes both direct and indirect connections.

[0027] The evaluation method and system provided in the following specific embodiments are applicable to any type of drive motor; the evaluation method and system are applicable to drive motors of pure electric vehicles; for example, the evaluation method and system are applicable to drive motors of hybrid vehicles; for ease of explanation, the following description uses the application of the evaluation method and system to drive motors of pure electric vehicles as an example.

[0028] In some embodiments, such as Figure 1 As shown, Figure 1 A flowchart illustrating a method for evaluating the noise of an electric drive assembly is provided. The evaluation method includes the following steps:

[0029] Step S1: Obtain time-domain noise and vibration data of the electric drive assembly under the vehicle state, and process it to obtain the first data of the drive motor order noise and the second data of the gearbox gear order noise.

[0030] Specifically, the entire electric drive assembly is installed on the vehicle, and tests are conducted under selected operating conditions to obtain time-domain noise and vibration data of the electric drive assembly in the vehicle state. The specific test environment is not limited; however, to maximize testing accuracy, a flat, quiet outdoor test track or a vehicle anechoic chamber can be selected. For ease of explanation, the anechoic chamber will be used as the test environment in the following description. Noise monitoring points are selected around the electric drive assembly. The specific location and number of monitoring points are not limited; detailed examples will be provided below. By acquiring time-domain noise and vibration data from the noise monitoring points, the first data of the drive motor's order noise and the second data of the reduction gear's order noise are obtained through processing. It should be noted that the first data represents the relationship between the drive motor's frequency and sound pressure level, and the second data represents the relationship between the reduction gear's frequency and sound pressure level. Any method that can convert the acquired time-domain noise and vibration data into a frequency-sound-pressure-level relationship is acceptable.

[0031] For example, by acquiring the raw time-domain data of the drive motor and gearbox gears during acceleration or deceleration using an information acquisition device, the relationship between time and sound pressure level can be obtained. This relationship can be formed into a two-dimensional planar graph. By tracking the rotational speed and performing FFT (Fourier Transform) post-processing on the data of the relationship between time and sound pressure level, the relationship between frequency, rotational speed, and sound pressure level can be obtained. This relationship can be formed into a three-dimensional graph. By slicing the data of the relationship between frequency, rotational speed, and sound pressure level in the three-dimensional graph to extract the required order data, the relationship between rotational speed and sound pressure level can be obtained. This relationship can be formed into a two-dimensional planar graph.

[0032] In the frequency domain, the difference between the gearbox gear order noise and the drive motor order noise in the whole vehicle state and the test bench state is constant. This means that at the same frequency, the differences in the gearbox gear and drive motor order noises are essentially equivalent, even after eliminating factors such as structural resonance in both the test bench and the whole vehicle. The reasoning is as follows: In the whole vehicle state, at the resonant speed corresponding to the gearbox gear order, the drive motor order does not resonate. If the conversion is based on speed, it will lead to a large deviation. Converting based on frequency takes resonance into account in both the test bench and whole vehicle data, reducing the deviation. Therefore, it is necessary to convert the relationship between speed and sound pressure level into a relationship between frequency and sound pressure level. All gearbox gear and drive motor orders are converted to a relationship based on the input shaft: o = z a / i a Where o is the order, z a i is the number of teeth of the driving tooth on the axis. a This refers to the transmission ratio of the input shaft relative to its corresponding shaft; for example, in a two-stage reduction gearbox, the input shaft gear, i a =1, order o=z a For the output shaft gear, assume the transmission ratio i between the shaft containing the output shaft drive gear and the input shaft is... a =3, o=z a / 3; The main order of the drive motor is also handled in the same way. Therefore, the horizontal axis of the curve results of all order results slices is the input shaft speed. The relationship between frequency and sound pressure level can be obtained by dividing the input shaft speed (unit: revolutions per minute) by 60.

[0033] Step S2: Obtain the time-domain noise vibration data of the gearbox gear under test conditions, and process it to obtain the third data of the gearbox gear order noise.

[0034] Specifically, after completing the testing in the whole vehicle state, the electric drive assembly is removed from the vehicle for testing in this state. The drive motor can be replaced by a tool housing, with the end cover of the tool housing pre-drilled for the dynamometer shaft. A high-speed input motor from the test bench replaces the electric drive assembly's drive motor as the power source. The test bench controls the torque, and the differential is connected to the test bench, which controls the dynamometer speed. It should be noted that when using the test bench, the input and output dynamometer speed and torque of the test bench should cover the characteristics of the drive motor. Time-domain noise vibration data of the gearbox gears in the test bench state is obtained at noise monitoring points. This data is then processed to obtain the third data of the gearbox gear order noise. It should be noted that this third data represents the relationship between the gearbox gear frequency and sound pressure level. Any method that can convert the acquired time-domain noise vibration data into a frequency-sound pressure level relationship is acceptable. Specific implementation methods have been described above and will not be repeated here. It is important to emphasize that the data acquisition and processing methods in the test bench state should be the same as those in the whole vehicle state.

[0035] Step S3: Calculate the difference between the second and third data at the same frequency, and subtract the difference from the first data to obtain the fourth data of the drive motor order noise in the test bench state.

[0036] Specifically, after completing tests in both the whole vehicle and bench conditions, we can obtain the following data: first, the relationship between drive motor frequency and sound pressure level in the whole vehicle condition; second, the relationship between gearbox gear frequency and sound pressure level in the gearbox condition; and third, the relationship between gearbox gear frequency and sound pressure level in the bench condition. In the frequency domain, the difference between the order noise of the gearbox gear and the drive motor in both conditions is constant. Using the second and third data points for the relationship between gearbox gear frequency and sound pressure level in the whole vehicle and bench conditions, we obtain the difference in order noise between these two conditions. This difference is used as an intermediate value for conversion. Subtracting this difference from the first data point for the relationship between drive motor frequency and sound pressure level yields the fourth data point for the relationship between drive motor frequency and sound pressure level in the bench condition. This fourth data point represents the estimated order noise data of the drive motor.

[0037] Step S4: Convert the fourth data at different frequencies into the order noise data of the drive motor at different speeds.

[0038] Specifically, after obtaining the fourth data point regarding the relationship between the drive motor frequency and sound pressure level under bench conditions, this fourth data needs to be converted into drive motor order noise data at the corresponding speed. Multiplying the motor frequency (in Hertz) of the fourth data point in the relationship between motor frequency and sound pressure level by 60 yields the relationship between speed and sound pressure level. Combining the gearbox gear order noise obtained from bench measurements with the estimated drive motor order noise under bench conditions, the vibration and noise level of the entire electric drive assembly can be obtained. After understanding the noise level of the relevant electric drive assembly, reasonable development goals can be formulated for newly developed drive assemblies based on the current noise level. This avoids under- or over-design, reduces the development cycle, and controls development costs to a certain extent.

[0039] This invention provides a method for evaluating the noise of an electric drive assembly. The method includes: acquiring time-domain noise and vibration data of the electric drive assembly in a vehicle state, and processing it to obtain first data of the drive motor order noise and second data of the gearbox gear order noise; acquiring time-domain noise and vibration data of the gearbox gear in a bench test state, and processing it to obtain third data of the gearbox gear order noise; calculating the difference between the second data and the third data at the same frequency, and subtracting the difference from the first data to obtain fourth data of the drive motor order noise in the bench test state; and converting the fourth data at different frequencies into drive motor order noise data at different speeds. In the frequency domain, the difference between the order noise of the gearbox gears and the order noise of the drive motor under vehicle and bench conditions is constant. By acquiring the time-domain noise and vibration data of the gearbox gears under vehicle and bench conditions respectively, the difference in order noise between the two conditions can be obtained. This difference is used as an intermediate quantity for conversion. By acquiring the order noise data of the drive motor under vehicle conditions and using the intermediate quantity, the order noise data of the drive motor under bench conditions can be estimated. Combining the gearbox gear order noise obtained from bench measurements and the estimated drive motor order noise under bench conditions, the vibration and noise level of the entire competitor's electric drive assembly can be obtained. This effectively assists in setting reasonable noise development targets at the beginning of the forward development of the electric drive assembly and guides the project to carry out reasonable design.

[0040] In some embodiments, such as Figure 2 As shown, Figure 2 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 1 The different assessment methods provided are, Figure 2 Step S2 includes:

[0041] Step S11: Obtain the raw time-domain data of the electric drive assembly under the vehicle state through the vibration and noise platform equipment.

[0042] Specifically, the vibration and noise platform equipment is used to obtain the raw time-domain data of the electric drive assembly under the vehicle condition. The vibration and noise platform equipment can be understood as the front end of NVH (noise, vibration and harshness) testing. By collecting data through the NVH front end equipment, the relationship between time and sound pressure level can be obtained.

[0043] Step S12: Post-process the original speed data to obtain the order noise data of the drive motor and the gearbox gear at the corresponding speed.

[0044] Specifically, by tracking the rotational speed and performing FFT post-processing on the collected data of the relationship between the drive motor's time and sound pressure level, the relationship between frequency, rotational speed, and sound pressure level can be obtained. Further data slicing of the three-dimensional graph of frequency, rotational speed, and sound pressure level to extract the required order data yields the relationship between rotational speed and sound pressure level, thus obtaining the order noise data of the drive motor. Similarly, by tracking the rotational speed and performing FFT post-processing on the collected data of the gearbox gear's time and sound pressure level, the relationship between frequency, rotational speed, and sound pressure level can be obtained. Further data slicing of the three-dimensional graph of frequency, rotational speed, and sound pressure level to extract the required order data yields the relationship between rotational speed and sound pressure level, thus obtaining the order noise data of the gearbox gear at the corresponding rotational speed.

[0045] Figure 2 Step S2 includes step S21, which involves acquiring the raw time-domain data of the gearbox gears in the bench state using a vibration and noise platform device.

[0046] Specifically, by acquiring the raw time-domain data of the gearbox teeth under test conditions through NVH front-end equipment, the relationship between time and sound pressure level can be obtained.

[0047] Step S22: Post-process the original speed data to obtain the gearbox gear order noise data at the corresponding speed.

[0048] Specifically, the relationship between time and sound pressure level of the gearbox gears collected under test conditions is tracked and post-processed using FFT to obtain the relationship between frequency, speed and sound pressure level. The relationship between frequency, speed and sound pressure level is then extracted by data order slicing of the three-dimensional graph of frequency, speed and sound pressure level to obtain the relationship between speed and sound pressure level, thereby obtaining the order noise data of the gearbox gears at the corresponding speed under test conditions.

[0049] In some embodiments, such as Figure 2 As shown, Figure 2 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 2 The different assessment methods provided are, Figure 2 Step S1 further includes:

[0050] Step S13: Convert the order noise data of the drive motor at the rotational speed into first order noise data at the frequency, and convert the order noise data of the gearbox gear at the rotational speed into second order noise data at the frequency.

[0051] Specifically, the relationship between the drive motor speed and sound pressure level needs to be converted into the first data of the relationship between the drive motor frequency and sound pressure level. Similarly, the relationship between the gearbox speed and sound pressure level needs to be converted into the second data of the relationship between the gearbox frequency and sound pressure level. The specific conversion scheme has been explained above and will not be repeated here.

[0052] Figure 2 Step S2 includes step S23, which converts the order noise data of the gearbox gear at the rotational speed into the third data of the order noise at the frequency.

[0053] Specifically, the relationship between the speed of the gearbox gear and the sound pressure level needs to be converted into the third data, which is the relationship between the gearbox gear frequency and the sound pressure level. The specific conversion scheme has been explained above and will not be repeated here.

[0054] In some embodiments, such as Figure 3 As shown, Figure 3 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 2 The different assessment methods provided are, Figure 3 Step S11 includes:

[0055] Step S111: In the vehicle state, acquire noise data at a preset distance from the drive motor and noise data at a preset distance from the gearbox gear.

[0056] Specifically, in the vehicle's state, noise data is acquired at a preset distance from the drive motor. This preset distance is not limited and can be determined based on actual conditions. For example, if the preset distance is 0.5 meters, a sensor can be placed at a distance of 0.5 meters from the drive motor to acquire noise data at that location. Alternatively, multiple preset distances can be used, such as placing a sensor at a distance of 0.5 meters from the drive motor and another at a distance of 1 meter from the drive motor to acquire noise data at the same location. The arrangement for acquiring noise data at a preset distance from the reduction gearbox gears can be the same as that for acquiring noise data at a preset distance from the drive motor; the specific arrangement will not be elaborated further.

[0057] Figure 3 Step S21 includes: Step S211, in the test bench state, acquiring noise data at a preset distance from the gearbox gear.

[0058] Specifically, after completing the testing in the whole vehicle state, monitoring in the bench test state is required. It is important to emphasize that the distance between the gearbox gear noise monitoring point and the gearbox gear in the bench test state should be the same as the distance in the whole vehicle state. For example, if the distance between the gearbox gear noise monitoring point and the gearbox gear is 0.2 meters in the whole vehicle state, then the distance between the gearbox gear noise monitoring point and the gearbox gear in the bench test state should also be 0.2 meters. This ensures consistency between the whole vehicle and the bench test, and establishes the relationship between the bench test and the whole vehicle using this measurement point.

[0059] In some embodiments, such as Figure 3 As shown, Figure 3 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 2 The different assessment methods provided are, Figure 3 Step S11 further includes:

[0060] Step S112: Under the condition of the whole vehicle, acquire noise data from multiple monitoring points around the drive motor and noise data from multiple monitoring points around the gearbox gear.

[0061] Specifically, to further ensure the accuracy of the acquired data, multiple monitoring points can be set up to acquire noise data from multiple monitoring points around the drive motor and multiple monitoring points around the gearbox gears. The specific arrangement of these monitoring points is not required. For example, such as... Figure 5 As shown, five monitoring points are arranged, specifically M1, M2, M3, M4, and M5. M5 is positioned on the drive motor. M1, M2, M3, and M4 are connected sequentially to form a square, with M5 located at the center of the square. The side length of the square is 1 meter, and the distance from M5 to M1, M2, M3, and M4 is approximately 0.7 meters. Setting up multiple monitoring points improves the accuracy of the acquired data. For example, as... Figure 5 As shown, nine monitoring points are arranged, specifically M1, M2, M3 to M9, with M5 positioned on the drive motor. M1, M7, M2, M8, M3, M9, M4, and M6 are connected sequentially to form a square, with M5 located at the center. The square has a side length of 1 meter. The distances from M5 to M1, M2, M3, and M4 are approximately 0.7 meters, and the distances from M5 to M6, M7, M8, and M9 are approximately 0.5 meters. Setting up multiple monitoring points improves the accuracy of the acquired data. For acquiring noise data from multiple monitoring points around the gearbox gears, the arrangement can be the same as for acquiring noise data from multiple monitoring points around the drive motor; the specific arrangement will not be elaborated further.

[0062] Figure 3Step S21 further includes: step S212, in the test bench state, acquiring noise data from multiple monitoring points around the gearbox gear.

[0063] Specifically, after completing the testing in the whole vehicle state, monitoring in the bench test state is required. It is important to emphasize that the arrangement of monitoring points around the gearbox gears in the bench test state should be the same as that in the whole vehicle state. For example, if five monitoring points are arranged around the gearbox gears during the whole vehicle state test, then five monitoring points should also be arranged around the gearbox gears in the bench test state, and their positions should be identical to ensure consistency between the whole vehicle and the bench. This measurement point system establishes the relationship between the bench and the whole vehicle. Furthermore, based on the setup of multiple noise monitoring points, the relationship between the average noise level at one noise monitoring point and the average noise level across multiple noise monitoring points can be obtained.

[0064] In some embodiments, such as Figure 4 As shown, Figure 4 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 2 The different assessment methods provided are, Figure 4 Step S11 further includes:

[0065] Step S113: Under the condition of the whole vehicle, acquire vibration data of the position of the drive motor bearing and the gearbox input shaft bearing.

[0066] Specifically, to further acquire vibration data and ensure its accuracy, vibration sensors can be installed at the drive motor bearing and the gearbox input shaft bearing. The number of sensors is not limited and can be determined based on actual needs. To ensure data accuracy, multiple vibration sensors can be used, and the vibration data obtained from multiple sensors can be processed to improve accuracy and avoid randomness. For example, under full vehicle testing conditions, three vibration sensors are installed at the drive motor bearing and three at the gearbox input shaft bearing. The data acquired from these three sensors are averaged to determine the vibration conditions at the drive motor bearing and gearbox input shaft bearing locations.

[0067] Figure 4 Step S21 further includes: step S213, in the test bench state, acquiring vibration data of the position of the input shaft bearing of the gearbox.

[0068] Specifically, after completing the testing in the whole vehicle state, monitoring in the bench test state is required. It is important to emphasize that the number and arrangement of vibration sensors at the gearbox input shaft bearing location in the bench test state must be the same as those in the whole vehicle state. For example, if three vibration sensors are installed at the gearbox input shaft bearing location during whole vehicle testing, then three vibration sensors should also be installed at the gearbox input shaft bearing location during bench testing, and their placement should be identical to ensure consistency between the whole vehicle and bench tests.

[0069] In some embodiments, such as Figure 6 As shown, Figure 6 A flowchart illustrating another method for evaluating the noise of an electric drive assembly is provided, which is similar to... Figure 1 The evaluation method provided differs in that, between step S3 and step S4, the evaluation method further includes:

[0070] Step S5: Change the operating conditions of the electric drive assembly and repeat steps S1 to S3 until the number of repetitions reaches the preset threshold.

[0071] Specifically, to predict the noise of the drive motor assembly under various operating conditions, multiple operating conditions can be tested. For example, step S5 includes: step S51, the operating conditions of the electric drive assembly include at least three different throttle opening modes. The selection of operating conditions can be determined according to actual needs and is not specifically limited. For example, the operating conditions of the electric drive assembly include full throttle acceleration, 50% throttle acceleration, and 25% throttle acceleration. After completing the full throttle acceleration test in both vehicle and bench conditions, the operating condition of the electric drive assembly is changed to 50% throttle acceleration for noise testing in both vehicle and bench conditions. After completing the 50% throttle acceleration test in both vehicle and bench conditions, the operating condition of the electric drive assembly is changed to 25% throttle acceleration for noise testing in both vehicle and bench conditions, until all preset operating condition tests are completed.

[0072] In the evaluation method Figure 6 Step S4 further includes: step S41, converting the fourth data at different frequencies into drive motor order noise data at different speeds until the number of repetitions reaches three.

[0073] Specifically, the fourth data at different frequencies under various operating conditions is converted into drive motor order noise data at different speeds. For example, if three operating conditions are tested, the fourth data at different frequencies under the three operating conditions needs to be converted into drive motor order noise data at different speeds.

[0074] This invention also provides an electric drive assembly noise assessment system, such as... Figure 7As shown, the evaluation system includes an acquisition module 100 and a processing module 200. The acquisition module 100 is used to acquire time-domain noise and vibration data of the electric drive assembly in a vehicle state. The processing module 200 is used to process and obtain first data of the drive motor order noise and second data of the gearbox gear order noise. The acquisition module 100 is also used to acquire time-domain noise and vibration data of the gearbox gear in a bench test state. The processing module 200 is also used to process and obtain third data of the gearbox gear order noise. The processing module 200 is also used to calculate the difference between the second data and the third data at the same frequency, and use the first data to subtract the difference to obtain fourth data of the drive motor order noise in the bench test state. The processing module 200 is also used to convert the fourth data at different frequencies into drive motor order noise data at different speeds.

[0075] In some embodiments, such as Figure 7 The acquisition module 100 is further configured to acquire the raw time-domain data of the electric drive assembly in the vehicle state through a vibration and noise platform device; the processing module 200 is further configured to post-process the rotational speed of the raw data to obtain the order noise data of the drive motor and the order noise data of the gearbox gear at the corresponding rotational speed; the acquisition module 100 is further configured to acquire the raw time-domain data of the gearbox gear in the test bench state through a vibration and noise platform device; the processing module 200 is further configured to post-process the rotational speed of the raw data to obtain the order noise data of the gearbox gear at the corresponding rotational speed. In some embodiments, such as Figure 7 As shown, the processing module 200 is further configured to convert the order noise data of the drive motor at the specified speed into first data of order noise at the specified frequency, and to convert the order noise data of the gearbox gear at the specified speed into second data of order noise at the specified frequency; the processing module 200 is further configured to convert the order noise data of the gearbox gear at the specified speed into third data of order noise at the specified frequency.

[0076] In some embodiments, such as Figure 7 As shown, the acquisition module 100 is further configured to acquire noise data at a preset distance from the drive motor and noise data at a preset distance from the gearbox gear in a vehicle state; the acquisition module 100 is also configured to acquire noise data at a preset distance from the gearbox gear in a test bench state. In some embodiments, such as Figure 7 As shown, the acquisition module 100 is also used to acquire noise data from multiple monitoring points around the drive motor and multiple monitoring points around the gearbox gear in the vehicle state; the acquisition module 100 is also used to acquire noise data from multiple monitoring points around the gearbox gear in the test bench state.

[0077] In some embodiments, such as Figure 7As shown, the acquisition module 100 is also used to acquire vibration data of the positions of the drive motor bearing and the gearbox input shaft bearing in the vehicle state; the acquisition module 100 is also used to acquire vibration data of the position of the gearbox input shaft bearing in the test bench state.

[0078] In some embodiments, such as Figure 7 As shown, the processing module 200 is further configured to change the operating conditions of the electric drive assembly, repeating steps S1 to S3 until the number of repetitions reaches a preset threshold. In some embodiments, such as Figure 7 As shown, the processing module 200 is also used to convert the fourth data at different frequencies into the order noise data of the drive motor at different speeds until the number of repetitions reaches three.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A method for evaluating the noise of an electric drive assembly, characterized in that, The evaluation method includes: The time-domain noise and vibration data of the electric drive assembly under the vehicle condition are acquired and processed to obtain the first data of the drive motor order noise and the second data of the gearbox gear order noise. The time-domain noise vibration data of the gearbox gear under test conditions is obtained, and the third data of the order noise of the gearbox gear is obtained by processing. Calculate the difference between the second data and the third data at the same frequency, and use the first data to subtract the difference to obtain the fourth data of the order noise of the drive motor in the test bench state; The fourth data at different frequencies is converted into the order noise data of the drive motor at different speeds.

2. The evaluation method according to claim 1, characterized in that, The acquisition of time-domain noise and vibration data of the electric drive assembly under vehicle conditions includes: The time-domain raw data of the electric drive assembly under vehicle conditions are obtained through vibration and noise platform equipment; The original data of rotational speed is post-processed to obtain the order noise data of the drive motor and the order noise data of the gearbox at the corresponding rotational speed. The acquisition of time-domain noise vibration data of the gearbox gears in the test bench state includes: The time-domain raw data of the gearbox gear in the bench state are obtained by a vibration and noise platform device; The original data of rotational speed is post-processed to obtain the gear order noise data of the reduction gearbox at the corresponding rotational speed.

3. The evaluation method according to claim 2, characterized in that, The processing yields the first data of the drive motor order noise and the second data of the gearbox gear order noise, including: The order noise data of the drive motor at the specified speed is converted into first order noise data at the specified frequency, and the order noise data of the gearbox gear at the specified speed is converted into second order noise data at the specified frequency. The third data obtained from the processing of the gearbox gear order noise includes: The order noise data of the gearbox gear at the specified speed is converted into third data of order noise at the same frequency as the second data.

4. The evaluation method according to claim 3, characterized in that, The acquisition of the raw time-domain data of the electric drive assembly under vehicle conditions via the vibration and noise platform equipment includes: In the vehicle state, noise data at a preset distance from the drive motor and noise data at a preset distance from the gearbox gear are acquired. The acquisition of the raw time-domain data of the gearbox gears in the test bench state via the vibration and noise platform equipment includes: In test bench mode, noise data is acquired at a preset distance from the gearbox gears.

5. The evaluation method according to any one of claims 2 to 4, characterized in that, The acquisition of the raw time-domain data of the electric drive assembly under vehicle conditions via the vibration and noise platform equipment includes: In the vehicle state, noise data from multiple monitoring points around the drive motor and noise data from multiple monitoring points around the gearbox gear are acquired. The acquisition of the raw time-domain data of the gearbox gears in the test bench state via the vibration and noise platform equipment includes: Noise data from multiple monitoring points around the gearbox gears were acquired in a test bench configuration.

6. The evaluation method according to claim 2, characterized in that, The acquisition of the raw time-domain data of the electric drive assembly under vehicle conditions via the vibration and noise platform equipment also includes: Under the condition of the whole vehicle, acquire vibration data of the positions of the drive motor bearing and the gearbox input shaft bearing; The acquisition of the raw time-domain data of the gearbox gears in the test bench state via the vibration and noise platform equipment includes: Vibration data of the gearbox input shaft bearing position were acquired under test bench conditions.

7. The evaluation method according to claim 1, characterized in that, Between the fourth data of the drive motor order noise obtained by subtracting the difference from the first data in the test bench state and the conversion of the fourth data at different frequencies into drive motor order noise data at different speeds, the evaluation method further includes: The operating conditions of the electric drive assembly are changed, and the acquisition of time-domain noise and vibration data of the electric drive assembly under the vehicle state is repeated, and the first data of the order noise of the drive motor and the second data of the order noise of the gearbox are processed to obtain the second data of the order noise of the gearbox. The time-domain noise vibration data of the gearbox gear under test conditions is obtained, and the third data of the order noise of the gearbox gear is obtained by processing. Calculate the difference between the second data and the third data at the same frequency, and use the first data to subtract the difference to obtain the fourth data of the order noise of the drive motor in the test state until the number of repetitions reaches a preset number threshold. The fourth data at different frequencies is converted into the order noise data of the drive motor at different speeds.

8. The evaluation method according to claim 7, characterized in that, Changing the operating conditions of the electric drive assembly includes: The operating conditions of the electric drive assembly include at least three different throttle opening modes; The step of converting the fourth data at different frequencies into drive motor order noise data at different speeds until the number of repetitions reaches a preset threshold includes: The fourth data at different frequencies is converted into the order noise data of the drive motor at different speeds until the number of repetitions reaches three.

9. A noise assessment system for an electric drive assembly, characterized in that, The evaluation system is used to perform the evaluation method according to any one of claims 1 to 8, and the evaluation system comprises: The acquisition module is used to acquire time-domain noise and vibration data of the electric drive assembly under the vehicle state, and process it to obtain the first data of the drive motor order noise and the second data of the gearbox gear order noise. The acquisition module is also used to acquire time-domain noise vibration data of the gearbox gear in bench condition, and process it to obtain third data of the order noise of the gearbox gear; The processing module is used to calculate the difference between the second data and the third data at the same frequency, and to obtain the fourth data of the order noise of the drive motor in the test bench state by subtracting the difference from the first data. The processing module is also used to convert the fourth data at different frequencies into drive motor order noise data at different speeds.

10. The evaluation system according to claim 9, characterized in that, The acquisition module is also used to acquire the original time-domain data of the electric drive assembly under the vehicle state through the vibration and noise platform equipment; The processing module is further configured to post-process the rotational speed of the original data to obtain the order noise data of the drive motor and the order noise data of the gearbox gear at the corresponding rotational speed. The acquisition module is also used to acquire the original time-domain data of the gearbox gear in the bench state through the vibration and noise platform equipment; The processing module is further configured to post-process the rotational speed of the original data to obtain the gear order noise data of the reduction gearbox at the corresponding rotational speed.

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