Assembly offline NVH (Noise Vibration and Harshness) detection method and system based on double-reference-axis order mode

Abstract

The invention discloses an assembly offline NVH (Noise Vibration and Harshness) detection method and system based on a double-reference shaft order mode. The method comprises the following steps: determining a driving motor shaft and a generator shaft as double reference shafts; according to the wheel end rotating speed or the engine shaft rotating speed, the rotating speeds of a driving motor shaft and a generator shaft are reversely deduced through speed ratio conversion; different NVH working conditions are established in the software parameter database, and different reference axes are synchronously matched; setting a resampling standard of signal processing; setting of monitoring parameters is completed in a software curve limit value configuration module, and the monitoring parameters comprise an order spectrogram, order slicing and modulation tracking; and NVH detection is carried out on the hybrid electric drive assembly based on the configured parameters and the double reference shafts. According to the method, order analysis is carried out by adopting double reference axes, all working modes, including a pure electric mode, a hybrid mode and a charging mode, of the hybrid electric drive assembly can be covered, the accuracy of order analysis is improved, the NVH problem can be recognized and positioned more accurately, and the detection rate of the NVH problem reaches 100%.

Description

Technical Field

[0001] The present invention relates to the technical field of NVH detection for hybrid electric drive assemblies, and particularly to a method and system for NVH detection during assembly off-line based on a dual reference axis order mode. Background Art

[0002] In recent years, driven by both national policies and market demands, the market share of hybrid electric vehicles has shown an explosive growth. The NVH (Noise, Vibration, and Harshness) performance of hybrid electric drive assemblies has directly become a key performance indicator that consumers focus on. Therefore, it is very necessary to conduct efficient and reliable NVH off-line detection for hybrid electric drive assemblies.

[0003] The hybrid electric drive assembly has a complex structure, including a drive motor, a generator, and the meshing of multiple pairs of gears. The NVH problems that occur mainly include quality problems such as electromagnetic noise, gear meshing noise, whistling noise, and knocking abnormal noise.

[0004] Currently, all existing hybrid electric drive assemblies use a single axis (output shaft) as the reference axis for NVH test order conversion. The NVH test conditions of the EOL (End Of Line) test bench formulated cannot cover the corresponding working modes of the whole vehicle. It can only test the NVH conditions in pure electric mode (the clutch is disengaged and the drive motor works) and hybrid mode (the generator and the engine work together), and cannot test the NVH conditions in charging mode (the drive motor does not work), resulting in the risk that the NVH failure modes of hybrid electric drive assemblies cannot be effectively identified / intercepted.

[0005] In addition, the hybrid electric drive assembly has a complex structure, including two motors and multiple pairs of gears. When performing order conversion with the output shaft as the reference axis during the NVH test, the rotational speed of the output shaft is slower than that of the input shaft, and the number of rotations is less, resulting in less data collected, rough order resolution, and a large order range due to the large number of teeth of the output gear, which is not conducive to accurate order analysis.

[0006] Therefore, it is necessary to develop an NVH detection method that can cover all working modes of hybrid electric drive assemblies to ensure that the NVH performance of hybrid electric drive assemblies meets the needs of the market and users. Summary of the Invention

[0007] Aiming at the problems in the background art, the purpose of the present invention is to provide a method and system for NVH detection during assembly off-line based on a dual reference axis order mode, aiming to solve the technical problems that the NVH detection of hybrid electric drive assemblies in the prior art cannot cover all working modes and the order analysis accuracy is insufficient.

[0008] To achieve the above object, in a first aspect, the present invention provides a method for detecting the NVH of a hybrid electric drive assembly under a dual reference axis order pattern, including:

[0009] Determine two speed sources as reference axes, where the reference axes include the drive motor shaft and the generator shaft;

[0010] According to the wheel end speed or the engine shaft speed, inversely calculate the speeds of the drive motor shaft and the generator shaft through speed ratio conversion;

[0011] Establish different NVH working conditions in the software parameter database and synchronously match different reference axes;

[0012] Set the resampling standard for signal processing;

[0013] Complete the setting of each monitoring parameter in the software curve limit configuration module, where the monitoring parameters include order spectrum, order slice, and modulation tracking; and

[0014] Perform NVH detection on the hybrid electric drive assembly based on the configured parameters and the dual reference axes.

[0015] In some alternative embodiments of the present invention, the working conditions of the hybrid electric drive assembly include pure electric mode, hybrid mode, and charging mode.

[0016] Preferably, in the pure electric mode, the drive motor shaft is used as the reference axis for NVH detection. At this time, the clutch is disengaged and the drive motor is working;

[0017] In the hybrid mode, the drive motor shaft and the generator shaft are used as the reference axes for NVH detection. At this time, the generator and the engine work together;

[0018] In the charging mode, the generator shaft is used as the reference axis for NVH detection. At this time, the drive motor does not work.

[0019] In some alternative embodiments of the present invention, the setting of the resampling standard for signal processing includes: the sampling frequency and sampling duration adjusted according to the speed of the corresponding reference axis.

[0020] Preferably, the resampling frequency is determined according to the maximum speed measured and the maximum order that can be seen.

[0021] More preferably, the calculation of the resampling frequency includes: determining the length of a data block and the number of turns included, calculating the order accuracy and the maximum order that can be seen, and calculating the maximum speed according to the sampling rate.

[0022] In some alternative embodiments of the present invention, the order spectrum is used to display the frequency component distribution based on different reference axes.

[0023] In some alternative embodiments of the present invention, the order slice is used to display the amplitude change of a specific order with the change of rotational speed.

[0024] In some alternative embodiments of the present invention, the modulation tracking includes Crest tracking and Kurtosis tracking, which are used to monitor abnormal vibration and noise characteristics.

[0025] In a second aspect, the present invention provides a total assembly off-line NVH detection system based on a dual-reference axis order mode, including:

[0026] A rotational speed source determination module, which is used to determine two rotational speed sources as reference axes, and the reference axes include a drive motor shaft and a generator shaft;

[0027] A rotational speed calculation module, which is used to inversely deduce the rotational speeds of the drive motor shaft and the generator shaft through speed ratio conversion according to the rotational speed at the wheel end or the rotational speed of the engine shaft;

[0028] A working condition establishment module, which is used to establish different NVH working conditions in a software parameter database and synchronously match different reference axes;

[0029] A resampling setting module, which is used to set the resampling standard for signal processing;

[0030] A monitoring parameter setting module, which is used to complete the setting of each monitoring parameter in a software curve limit configuration module, and the monitoring parameters include order spectrogram, order slice and modulation tracking; and

[0031] An NVH detection module, which is used to perform NVH detection on the hybrid electric drive assembly based on the configured parameters and the dual-reference axes.

[0032] In some alternative embodiments of the present invention, the different NVH working conditions include pure electric mode, hybrid mode and charging mode.

[0033] Preferably, in the pure electric mode, the detection execution module performs NVH detection with the drive motor shaft as the reference axis. At this time, the clutch is disengaged and the drive motor is working;

[0034] In the hybrid mode, the detection execution module performs NVH detection with the drive motor shaft and the generator shaft as the reference axes. At this time, the generator and the engine work together;

[0035] In the charging mode, the detection execution module performs NVH detection with the generator shaft as the reference axis. At this time, the drive motor does not work.

[0036] In some alternative embodiments of the present invention, the resampling setting module is further used to determine the resampling frequency according to the maximum rotational speed of the test and the maximum order that can be seen.

[0037] In some alternative embodiments of the present invention, the order spectrum diagram set by the monitoring parameter setting module is used to display the frequency component distribution based on different reference axes, the order slice is used to display the amplitude change of a specific order with the change of rotational speed, and the modulation tracking includes Crest tracking and Kurtosis tracking, which are used to monitor abnormal vibration and noise characteristics.

[0038] In a third aspect, the present invention provides an electronic device, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus; the memory is used to store a computer program; when the processor executes the program stored on the memory, it implements the method described in any one of the first aspects.

[0039] In a fourth aspect, the present invention provides a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, it implements the method described in any one of the first aspects.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. Through the dual-reference-axis order analysis method, the present invention realizes the NVH detection function of the hybrid electric drive assembly under all working conditions (pure electric + hybrid + charging), solves the technical problem that the existing single-axis reference method cannot cover all working modes, and makes the NVH problem detection rate reach 100%;

[0042] 2. By reasonably selecting the reference axis, the present invention improves the accuracy of order analysis. Selecting a suitable reference axis for order analysis under different working conditions improves problems such as rough order resolution and large order range caused by using the output shaft as a reference in the traditional method;

[0043] 3. The present invention jointly develops the NVH test software at zero cost and can be applied to all hybrid projects, saving the software development and application costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the disclosed embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. These drawings are only for illustrative purposes and are not intended to limit the protection scope of the present invention.

[0045] Figure 1 is the order spectrum diagram with the drive motor shaft (EM_Shaft) as the reference axis in the embodiment of the present invention;

[0046] Figure 2 is the order spectrum diagram with the generator shaft (Gen_Shaft) as the reference axis in the embodiment of the present invention;

[0047] Figure 3It is the order tracking diagram with the drive motor shaft (EM_Shaft) as the reference shaft in the embodiment of the present invention;

[0048] Figure 4 It is the Crest tracking diagram with the generator shaft (Gen_Shaft) as the reference shaft in the embodiment of the present invention;

[0049] Figure 5 It is the Kurtosis tracking diagram with the generator shaft (Gen_Shaft) as the reference shaft in the embodiment of the present invention;

[0050] Figure 6 It is the dual-reference-axis order NVH detection flow chart in the embodiment of the present invention;

[0051] Figure 7 It is a schematic diagram of an electronic device provided in the embodiment of the present invention. Detailed implementation manners

[0052] The technical solutions (including the preferred technical solutions) of the present invention will be further described in detail below by way of the accompanying drawings and by listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] Embodiment 1

[0054] The present invention provides a method for detecting the NVH of the assembled product at the end of the production line based on the dual-reference-axis order mode, as Figure 6 shown, the method includes the following steps:

[0055] Step S1: Determine two speed sources as reference shafts, and the reference shafts include the drive motor shaft and the generator shaft.

[0056] In this step, according to the structural characteristics of the hybrid electric drive assembly, two main speed sources are determined, namely the drive motor shaft (EM_Shaft) and the generator shaft (Gen_Shaft), which play different roles in different working modes. The drive motor shaft is mainly responsible for driving the vehicle, and the generator shaft is mainly responsible for power generation and assisting in driving. By using these two shafts as reference shafts at the same time, the NVH characteristics of the hybrid electric drive assembly under various working conditions can be captured more comprehensively.

[0057] Step S2: According to the wheel-end speed or the engine shaft speed, inversely calculate the speeds of the drive motor shaft and the generator shaft through speed ratio conversion.

[0058] In actual tests, the wheel-end speed or engine shaft speed can usually be directly measured, and then based on the transmission system design of the hybrid electric drive assembly, the speeds of the drive motor shaft and the generator shaft can be calculated using the transmission ratios between the gears at all levels.

[0059] In this step, based on the known wheel-end speed or engine shaft speed and combined with the speed ratio relationship of the hybrid electric drive assembly, the speeds of the drive motor shaft and the generator shaft are calculated in reverse.

[0060] Specifically, the conversion can be performed according to the following relational expressions:

[0061] Drive motor shaft speed = wheel-end speed × total transmission ratio from the wheel-end to the drive motor shaft

[0062] Generator shaft speed = engine shaft speed × transmission ratio from the engine shaft to the generator shaft

[0063] More specifically, when the wheel-end speed is a and the drive motor speed ratio is b, the drive motor shaft speed can be calculated using the formula: drive motor shaft speed = a × b.

[0064] Similarly, when the engine shaft speed is c and the generator speed ratio is d, the generator shaft speed can be calculated using the formula: generator shaft speed = c × d.

[0065] Step S3: Establish different NVH working conditions in the software parameter database and synchronously match different reference shafts.

[0066] In this step, according to the working characteristics of the hybrid electric drive assembly, different NVH working conditions are established in the parameter database of the NVH test software, mainly including pure electric mode, hybrid mode, and charging mode. At the same time, the corresponding reference shafts are matched for each working condition.

[0067] That is to say, according to the working mode of the hybrid electric drive assembly, at least the following three working conditions are established:

[0068] (1) Pure electric mode: At this time, the clutch is disengaged, the drive motor works, and the generator does not work. In this mode, the drive motor shaft is selected as the reference shaft for NVH detection;

[0069] (2) Hybrid mode: At this time, the generator and the engine work together, and the drive motor also works. In this mode, both the drive motor shaft and the generator shaft are used as reference shafts for NVH detection;

[0070] (3) Charging mode: At this time, the drive motor does not work, and the generator works to charge the battery. In this mode, the generator shaft is selected as the reference shaft for NVH detection.

[0071] Step S4: Set the resampling standard for signal processing.

[0072] For different reference axes, corresponding signal resampling criteria are set, including parameters such as sampling frequency and sampling duration.

[0073] For example, for the drive motor shaft, since its rotational speed is usually high, a higher sampling frequency can be set; for the generator shaft, appropriate sampling criteria can be set according to its typical operating speed range.

[0074] In this step, the resampling frequency is determined based on the maximum rotational speed tested and the maximum order that can be seen.

[0075] Specifically, assume that 1 data block (block length) contains 1024 points, and 1 data block contains 4 revolutions. Then the order accuracy is 1 / 4, and the maximum order that can be seen is 1024 / 4 / 2 = 128. If a sampling rate of 50KHz is configured, the maximum rotational speed is 50000 / 2 / 128×60 = 11718rpm.

[0076] By setting appropriate resampling criteria, it can be ensured that sufficient order accuracy and range can be obtained during order analysis, thereby improving the ability to identify and analyze NVH problems.

[0077] Step S5: Complete the setting of each monitoring parameter in the software curve limit configuration module. The monitoring parameters include order spectrogram, order slice, and modulation tracking.

[0078] In this step, according to the NVH characteristics of the hybrid electric drive assembly, corresponding monitoring parameters are set, including:

[0079] 1. Order spectrogram: Used to display the frequency component distribution based on different reference axes. As Figure 1 shown is the order spectrogram with the drive motor shaft (EM_Shaft) as the reference axis, Figure 2 shown is the order spectrogram with the generator shaft (Gen_Shaft) as the reference axis. Through the order spectrogram, the distribution of vibration or noise components at different orders can be visually observed.

[0080] 2. Order slice: Used to display the amplitude change of a specific order with the change of rotational speed. As Figure 3 shown is the order tracking diagram with the drive motor shaft (EM_Shaft) as the reference axis. Through the order slice, the vibration or noise amplitude change of a specific order at different rotational speeds can be observed, which helps to identify NVH problems related to rotational speed.

[0081] 3. Modulation tracking: Includes Crest tracking and Kurtosis tracking, which are used to monitor abnormal vibration and noise characteristics. As Figure 4 shown is the Crest tracking diagram with the generator shaft (Gen_Shaft) as the reference axis,Figure 5 Shown is the Kurtosis tracking diagram with the generator shaft (Gen_Shaft) as the reference axis. The Crest factor refers to the ratio of the signal peak value to the root mean square value and can be used to detect impulsive vibrations or noises; Kurtosis is a statistic describing the kurtosis of the signal distribution and can be used to detect abnormal vibrations or noises with non-normal distributions.

[0082] Step S6: Perform NVH detection on the hybrid electric drive assembly based on the configured parameters and the dual reference axes.

[0083] In this step, according to the parameters configured in the previous steps, use the dual reference axes to perform a comprehensive NVH detection on the hybrid electric drive assembly, covering all working modes such as pure electric mode, hybrid mode, and charging mode.

[0084] By adopting the dual reference axes for order analysis, the NVH problems of the hybrid electric drive assembly can be detected and analyzed more comprehensively and accurately, improving the detection rate of NVH problems and ensuring that the NVH performance of the hybrid electric drive assembly meets the needs of the market and users.

[0085] Embodiment 2

[0086] Based on the method of Embodiment 1, this embodiment details how to select appropriate reference axes for NVH detection under different working conditions.

[0087] In pure electric mode, the hybrid electric drive assembly is mainly powered by the drive motor and the generator does not work. At this time, the noises and vibrations mainly come from the drive motor and its related transmission system. Therefore, it is more appropriate to select the drive motor shaft as the reference axis, which can be directly associated with the order characteristics generated by the drive motor, facilitating the analysis of the electromagnetic noise of the drive motor and the related gear meshing noise.

[0088] Specifically, in the NVH detection of pure electric mode, the sampling duration is not less than the time for the drive motor shaft to rotate 10 circles to ensure that enough data is collected for order analysis. Then, according to the actual speed of the drive motor shaft, calculate its corresponding characteristic orders, focus on the orders related to the number of motor pole pairs and the gear meshing orders, and monitor whether the amplitudes of these characteristic orders exceed the preset limits.

[0089] In hybrid mode, both the drive motor and the generator are working, and the noises and vibrations from these two power sources need to be monitored. At this time, using both the drive motor shaft and the generator shaft as reference axes and performing order analysis separately can comprehensively capture various possible NVH problems.

[0090] Specifically, in the NVH detection of the hybrid mode, it is necessary to simultaneously collect the rotational speed signals of two shafts, and then perform order analysis with these two shafts as references respectively. For the drive motor shaft, the characteristic orders related to the drive motor are concerned; for the generator shaft, the characteristic orders related to the generator and the engine are concerned. Such a dual-reference shaft analysis can effectively distinguish noises and vibrations from different sources and improve the accuracy of fault diagnosis.

[0091] In the charging mode, the drive motor does not work, and the generator works to charge the battery. At this time, the noises and vibrations mainly come from the generator and its related transmission system. Therefore, it is more appropriate to select the generator shaft as the reference shaft, which can be directly associated with the order characteristics generated by the generator.

[0092] Specifically, in the NVH detection of the charging mode, the sampling duration is not less than the time for the generator shaft to rotate 10 circles. Then, according to the actual rotational speed of the generator shaft, calculate its corresponding characteristic orders, focus on the orders related to the number of generator pole pairs and the relevant gear meshing orders, and monitor whether the amplitudes of these characteristic orders exceed the preset limits.

[0093] Embodiment 3

[0094] This embodiment provides a total assembly off-line NVH detection system based on the dual-reference shaft order mode. The system includes the following modules:

[0095] Rotational speed source determination module: used to determine two rotational speed sources as reference shafts, and the reference shafts include the drive motor shaft and the generator shaft. This module determines the key rotational speed sources by analyzing the structure and working principle of the hybrid electric drive assembly, providing a reference basis for subsequent order analysis.

[0096] Rotational speed calculation module: used to reverse calculate the rotational speeds of the drive motor shaft and the generator shaft based on the wheel-end rotational speed or the engine shaft rotational speed through speed ratio conversion. This module establishes a speed ratio relationship model between each shaft according to the transmission chain relationship of the hybrid electric drive assembly to achieve reverse calculation of rotational speeds.

[0097] Operating condition establishment module: used to establish different NVH operating conditions in the software parameter database and synchronously match different reference shafts. This module establishes different NVH operating conditions including the pure electric mode, the hybrid mode, and the charging mode according to the working mode characteristics of the hybrid electric drive assembly, and assigns appropriate reference shafts to each operating condition.

[0098] Resampling setting module: used to set the resampling standard for signal processing. This module calculates and sets an appropriate resampling frequency according to the maximum rotational speed of the test and the maximum order that can be seen, ensuring that the accuracy and range of order analysis meet the requirements.

[0099] Monitoring parameter setting module: used to complete the setting of each monitoring parameter in the software curve limit configuration module. The monitoring parameters include order spectrum diagram, order slice, and modulation tracking. This module configures corresponding monitoring parameters and limits according to the NVH characteristics of the hybrid electric drive assembly, providing a basis for the detection and determination of NVH problems.

[0100] NVH detection module: used to perform NVH detection on the hybrid electric drive assembly based on the configured parameters and dual reference axes. This module executes the actual NVH test process, including steps such as data acquisition, signal processing, order analysis, and result determination, realizing a comprehensive detection of the NVH performance of the hybrid electric drive assembly under all working conditions.

[0101] In this system, each module can be implemented by software on a computer or dedicated NVH test equipment, or can be implemented by a hardware circuit or a combination of both. The inputs of the system include vibration signals and rotational speed signals from sensors, and the outputs include various NVH analysis results and judgment conclusions.

[0102] Embodiment 4

[0103] Based on the system of Embodiment 3, this embodiment details how the system is applied in an actual production line.

[0104] In the off-line detection link of the hybrid electric drive assembly production line, this system is integrated into the EOL test bench. The test bench is equipped with a drive motor and a load motor, capable of simulating various working conditions. Acceleration sensors and rotational speed sensors are installed on the bench for collecting vibration signals and rotational speed signals.

[0105] During the pure electric mode test, the test bench controls the drive motor to operate according to a preset rotational speed curve, while keeping the generator non-operational. The system automatically selects the drive motor shaft as the reference axis for NVH data acquisition and order analysis.

[0106] During the hybrid mode test, the test bench controls both the drive motor and the generator to operate according to a preset rotational speed curve. The system simultaneously uses the drive motor shaft and the generator shaft as reference axes for NVH analysis with dual-axis reference.

[0107] During the charging mode test, the test bench controls the generator to work, while keeping the drive motor non-operational. The system automatically selects the generator shaft as the reference axis for NVH data acquisition and order analysis.

[0108] In this way, the system can comprehensively cover all working modes of the hybrid electric drive assembly, ensuring that each off-line product has undergone a comprehensive NVH detection, effectively improving product quality and user satisfaction.

[0109] Embodiment 5

[0110] As Figure 7 shown, the present invention provides an electronic device, including a processor 1, a communication interface 2, a memory 3, and a communication bus 4. Among them, the processor 1, the communication interface 2, and the memory 3 complete mutual communication through the communication bus 4; the memory 4 is used for storing a computer program; when the processor 1 executes the program stored on the memory 3, it implements the NVH detection method for assembly offline under the dual reference axis order mode described in Embodiment 1 or 2.

[0111] The processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0112] The memory may include a random access memory (RAM), or may also include a non-volatile memory (NVM), such as at least one disk memory.

[0113] The memory may be a volatile memory, such as a random access memory (RAM); the memory may also be a non-volatile memory, such as a read-only memory, a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD), or the memory is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may be a combination of the above memories.

[0114] Embodiment 6

[0115] The present invention provides a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, it is the NVH detection method for assembly offline under the dual reference axis order mode described in Embodiment 1.

[0116] The present invention can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid-state disk (SSD)).

[0117] It is easily understood by those skilled in the art that the above is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, combinations, substitutions, improvements, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An NVH detection method for assembly offline under the dual-reference axis order mode, characterized in that including: Determine two speed sources as reference axes, where the reference axes include the drive motor shaft and the generator shaft; According to the wheel-end speed or the engine shaft speed, inversely calculate the speeds of the drive motor shaft and the generator shaft through speed ratio conversion; Establish different NVH working conditions in the software parameter database and synchronously match different reference axes; Set the resampling standard for signal processing; Complete the setting of each monitoring parameter in the software curve limit configuration module, where the monitoring parameters include order spectrum diagram, order slice, and modulation tracking; and Perform NVH detection on the hybrid electric drive assembly based on the configured parameters and the dual reference axes.

2. The NVH detection method for assembly offline under the dual-reference-axis order pattern according to claim 1, wherein: The working conditions of the hybrid electric drive assembly include pure electric mode, hybrid mode, and charging mode.

3. The method for NVH detection during assembly off-line in the order mode based on dual reference axes according to claim 2, characterized in that: In pure electric mode, use the drive motor shaft as the reference axis for NVH detection. At this time, the clutch is disengaged and the drive motor is working; In hybrid mode, use the drive motor shaft and the generator shaft as the reference axes for NVH detection. At this time, the generator and the engine work together; In charging mode, use the generator shaft as the reference axis for NVH detection. At this time, the drive motor does not work.

4. The NVH detection method for the assembly offline under the dual-reference-axis order pattern according to claim 1, wherein: The setting of the resampling standard for signal processing includes: the sampling frequency and sampling duration adjusted according to the speed of the corresponding reference axis; determining the resampling frequency according to the maximum speed tested and the maximum order that can be seen.

5. The NVH detection method for the assembly offline under the dual reference axis order pattern according to claim 4, characterized in that: The calculation of the resampling frequency includes: determining the length of a data block and the number of turns included, calculating the order accuracy and the maximum order that can be seen, and calculating the maximum speed according to the sampling rate.

6. The NVH detection method for assembly offline under the dual reference axis order mode according to claim 1, wherein: The order spectrum diagram is used to display the frequency component distribution based on different reference axes; the order slice is used to display the amplitude change of a specific order with the change of speed; the modulation tracking includes Crest tracking and Kurtosis tracking, which are used to monitor abnormal vibration and noise characteristics.

7. An assembly offline NVH detection system based on a dual-reference axis order pattern, characterized in that, including: A speed source determination module for determining two speed sources as reference axes, where the reference axes include the drive motor shaft and the generator shaft; A speed calculation module for inversely calculating the speeds of the drive motor shaft and the generator shaft through speed ratio conversion according to the wheel-end speed or the engine shaft speed; A working condition establishment module for establishing different NVH working conditions in the software parameter database and synchronously matching different reference axes; A resampling setting module for setting the resampling standard for signal processing; A monitoring parameter setting module for completing the setting of each monitoring parameter in the software curve limit configuration module, where the monitoring parameters include order spectrum diagram, order slice, and modulation tracking; and An NVH detection module for performing NVH detection on the hybrid electric drive assembly based on the configured parameters and the dual reference axes.

8. The NVH detection system for assembly off-line based on the dual reference axis order mode according to claim 7, wherein: The different NVH working conditions include pure electric mode, hybrid mode, and charging mode; In pure electric mode, the detection execution module uses the drive motor shaft as the reference axis for NVH detection. At this time, the clutch is disengaged and the drive motor is working; In hybrid mode, the detection execution module uses the drive motor shaft and the generator shaft as the reference axes for NVH detection. At this time, the generator and the engine work together; In the charging mode, the detection execution module performs NVH detection with the generator shaft as the reference shaft, and at this time, the drive motor does not work.

9. The NVH detection system for assembly off-line based on the dual reference axis order mode according to claim 7, wherein: The resampling setting module is further configured to determine the resampling frequency according to the maximum rotational speed tested and the maximum order that can be seen.

10. The NVH detection system for assembly offline under the dual-reference-axis order pattern according to claim 7, wherein: The order spectrogram set by the monitoring parameter setting module is used to display the frequency component distribution based on different reference shafts, the order slice is used to display the amplitude change of a specific order with the rotational speed, and the modulation tracking includes Crest tracking and Kurtosis tracking, which are used to monitor abnormal vibration and noise characteristics.

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