A test method and system for new energy vehicle gear NVH performance

Abstract

The application relates to the technical field of NVH performance testing, and discloses a testing method and system for the NVH performance of a gear of a new energy vehicle, which comprises the following steps: synchronously collecting a rotating speed signal, a vibration signal and a sound pressure signal based on a rotating speed scanning working condition, determining a gear meshing frequency based on the rotating speed signal, performing order conversion processing on the vibration signal and the sound pressure signal, determining a stiffness adjustment range and a damping simulation constraint based on the installation position of a gear electric drive assembly bench in a whole vehicle and a suspension connection relationship, repeatedly performing rotating speed scanning under different combinations of stiffness and damping, sorting a plurality of whole vehicle boundary conditions based on a meshing order change amount, taking the whole vehicle boundary condition with the maximum meshing order change amount as a target boundary condition, and determining a gear NVH test result of a whole vehicle operating state based on a gear howling interval. The application ensures the reliability of the test by determining the stiffness adjustment range and the damping simulation constraint.

Description

Technical Field

[0001] This invention relates to the field of NVH performance testing technology, and more specifically, to a testing method and system for the NVH performance of gears in new energy vehicles. Background Technology

[0002] New energy vehicle power systems typically employ an integrated motor and reducer assembly. Within this assembly, gear transmission matches the motor speed with the wheel speed. During vehicle operation, gear meshing generates periodic excitation. When this excitation is transmitted to the vehicle body through bearings, housings, and suspension structures, it creates noise within the vehicle. Currently, the NVH performance of gears in new energy vehicles is tested using a gear electric drive assembly bench. However, during bench testing, variations in the installation state of the gear electric drive assembly connected to the vehicle body structure via the suspension system alter the stiffness and damping characteristics of the vehicle's suspension structure, changing the vibration transmission path and natural frequency. This results in different response characteristics of the gear meshing excitation within the vehicle structure. For example, the gear electric drive assembly may not exhibit gear squealing during testing, but it may do so during road tests or bench tests. Because the impact of vehicle installation conditions on gear NVH response is not considered, the gear NVH data obtained from bench tests cannot reflect the gear noise characteristics under actual vehicle operating conditions.

[0003] Therefore, it is necessary to design a testing method and system for the NVH performance of gears in new energy vehicles to solve the problems existing in the current technology. Summary of the Invention

[0004] In view of this, the present invention proposes a test method and system for the NVH performance of gears in new energy vehicles, aiming to solve the problem that the failure to consider the influence of vehicle installation conditions on gear NVH response leads to the gear NVH data obtained by bench testing failing to reflect the gear noise characteristics under the actual operating conditions of the vehicle.

[0005] In one aspect, this invention proposes a testing method for the NVH performance of gears in new energy vehicles, comprising:

[0006] A speed encoder, a housing vibration acceleration sensor, and a sound pressure sensor are arranged on the gear electric drive assembly bench to synchronously acquire speed signals, vibration signals, and sound pressure signals based on the speed scanning condition.

[0007] Based on the rotational speed signal, the gear meshing frequency is determined, and the vibration signal and sound pressure signal are processed by order transformation to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, the stiffness adjustment range and damping simulation constraints are determined. The rotational speed is repeatedly scanned under different combinations of stiffness and damping to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions.

[0008] Frequency band energy statistics are performed on all order spectrum data, and the amplitude sequences of gear meshing order and sideband frequency are extracted. Based on the amplitude sequences, the meshing order variation under different vehicle boundary conditions is determined. Based on the meshing order variation, multiple sets of vehicle boundary conditions are sorted, and the vehicle boundary condition with the largest meshing order variation is taken as the target boundary condition. Based on the target boundary condition, the meshing order amplitude curve is determined.

[0009] The engagement order amplitude curve is compared with a preset order threshold at each speed position. When the engagement order amplitude at any speed position exceeds the preset order threshold, the speed range corresponding to that speed position is determined as the gear squealing range. The gear NVH test results of the whole vehicle operating state are determined based on the gear squealing range.

[0010] Furthermore, in determining the gear meshing order spectrum at the corresponding rotational speed position, the process includes: determining the gear input shaft rotational speed based on the rotational speed signal collected by the rotational speed encoder, determining the gear meshing frequency sequence based on the number of gear teeth and the transmission ratio, dividing the vibration signal and sound pressure signal into several sampling windows based on the time sequence, performing resampling processing in each sampling window, performing a fast Fourier transform on the resampling processing result, determining the order spectrum based on the order relationship corresponding to the gear input shaft rotational speed, extracting the gear meshing order and adjacent order components from the order spectrum, and determining the gear meshing order spectrum at the corresponding rotational speed position based on the rotational speed sequence.

[0011] Furthermore, in determining the stiffness adjustment range and damping simulation constraints, the process includes: determining the coordinates of the connection points of the suspension structure based on the installation position of the gear electric drive assembly bench in the vehicle, determining the bench installation reference position based on the connection point coordinates, setting stiffness components and damping adjustment components based on the bench installation reference position, determining several stiffness values ​​based on the combination of elastic elements of the stiffness components, determining the damping value corresponding to each stiffness value based on the damping coefficient of the damping element in the damping adjustment component, and determining the stiffness adjustment range and damping simulation constraints based on all stiffness values ​​and the corresponding damping values.

[0012] Furthermore, when determining the order spectrum data corresponding to multiple sets of vehicle boundary conditions, the process includes: sequentially loading the stiffness adjustment range and damping simulation constraints as each set of vehicle boundary conditions, performing a speed scan in each set of vehicle boundary conditions, determining the gear meshing order spectrum corresponding to the vehicle boundary conditions, numbering all gear meshing order spectra, and establishing order spectrum data containing the number, speed position, and gear meshing order spectrum.

[0013] Furthermore, when extracting the amplitude sequence of gear meshing order and sideband frequency, the process includes: determining the order interval where the gear meshing order is located in the order spectrum data, setting order sideband intervals on both sides of the order interval, determining the order energy value at the corresponding rotational speed position based on the order amplitude in the order interval and sideband interval, determining the order energy sequence based on the rotational speed sequence and each order energy value, and determining the amplitude sequence of gear meshing order and sideband frequency according to the order energy sequence.

[0014] Furthermore, when determining the target boundary conditions, the process includes: extracting the engagement order amplitude corresponding to different vehicle boundary conditions, taking the difference between the engagement order amplitudes as the engagement order change, normalizing all engagement order changes, sorting the normalization results, and determining the target boundary conditions based on the sorting results.

[0015] Furthermore, in determining the meshing order amplitude curve, the process includes: determining a target amplitude sequence based on the target boundary conditions, and determining the corresponding meshing order amplitude curve based on the target amplitude sequence.

[0016] Furthermore, when performing position comparison by rotational speed, the process includes: obtaining the amplitude in the meshing order amplitude curve based on the rotational speed sequence, and comparing it point by point with the corresponding preset order threshold. When the amplitude of the continuous rotational speed position is greater than the corresponding preset order threshold, the gear squealing interval is determined based on the continuous rotational speed position.

[0017] Furthermore, when determining the gear NVH test results for the overall vehicle operating status, the process includes: recording the speed range corresponding to the gear squealing interval, and outputting the corresponding gear NVH test results based on the speed range.

[0018] Compared with existing technologies, the advantages of this invention are as follows: By arranging corresponding sensors on the gear electric drive assembly test bench and synchronously collecting speed signals, vibration signals, and sound pressure signals, a comprehensive and time-synchronized data foundation can be provided for gear NVH characteristic analysis, avoiding analysis errors caused by signal loss or asynchrony. Furthermore, by performing order transformation processing on the signals to obtain the gear meshing order spectrum, and combining this with the installation position of the gear electric drive assembly in the vehicle and the suspension connection relationship to determine the stiffness adjustment range and damping simulation constraints, the influence of the stiffness and damping characteristics of the vehicle's suspension structure on the vibration transmission path and natural frequency can be reproduced on the test bench, avoiding... To address the risks of bench testing having limited boundary conditions and being disconnected from the vehicle's installation status, this paper analyzes the order spectrum data under multiple vehicle boundary conditions. This involves performing frequency band energy statistics, amplitude sequence extraction, and sorting the meshing order changes to identify the target boundary conditions that have the greatest impact on gear NVH response. This allows for precise matching of the gear excitation response characteristics during actual vehicle operation. By comparing the meshing order amplitude curve corresponding to the target boundary condition with a preset order threshold at each speed to determine the gear squealing range, the paper solves the problems of traditional bench testing failing to accurately predict vehicle gear squealing and inconsistent test data with actual vehicle performance, thus improving the reliability of gear NVH test results.

[0019] On the other hand, this application also provides a testing system for the NVH performance of gears in new energy vehicles, used to apply the above-mentioned testing method for the NVH performance of gears in new energy vehicles, including:

[0020] The acquisition unit is configured to synchronously acquire rotation speed signals, vibration signals, and sound pressure signals based on rotation speed scanning conditions.

[0021] The analysis unit is configured to determine the gear meshing frequency based on the rotational speed signal, and to perform order transformation processing on the vibration signal and sound pressure signal to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, it determines the stiffness adjustment range and damping simulation constraints, and repeatedly performs rotational speed scanning under different combinations of stiffness and damping conditions to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions.

[0022] The processing unit is configured to perform frequency band energy statistics on all order spectrum data, extract the amplitude sequence of gear meshing order and sideband frequency, determine the meshing order variation under different vehicle boundary conditions based on the amplitude sequence, sort multiple sets of vehicle boundary conditions based on the meshing order variation, take the vehicle boundary condition with the largest meshing order variation as the target boundary condition, and determine the meshing order amplitude curve based on the target boundary condition.

[0023] The test unit is configured to compare the meshing order amplitude curve with a preset order threshold at each rotational speed. When the meshing order amplitude at any rotational speed exceeds the preset order threshold, the rotational speed range corresponding to that rotational speed position is determined as the gear squealing range. Based on the gear squealing range, the gear NVH test result of the vehicle's operating state is determined.

[0024] It is understandable that the above-mentioned test method and system for NVH performance of gears in new energy vehicles have the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A flowchart illustrating a testing method for the NVH performance of gears in new energy vehicles, provided as an embodiment of the present invention;

[0027] Figure 2 This is a functional block diagram of a testing system for the NVH performance of gears in new energy vehicles, provided as an embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] See Figure 1 As shown in some embodiments of this application, a method for testing the NVH performance of gears in new energy vehicles includes:

[0031] S100: A speed encoder, a housing vibration acceleration sensor, and a sound pressure sensor are arranged on the gear electric drive assembly bench to synchronously collect speed signals, vibration signals, and sound pressure signals based on the speed scanning condition.

[0032] S200: Based on the rotational speed signal, the gear meshing frequency is determined, and the vibration signal and sound pressure signal are processed by order transformation to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, the stiffness adjustment range and damping simulation constraints are determined. The rotational speed is repeatedly scanned under different combinations of stiffness and damping to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions.

[0033] S300: Perform frequency band energy statistics on all order spectrum data, extract the amplitude sequence of gear meshing order and sideband frequency, determine the meshing order variation under different vehicle boundary conditions based on the amplitude sequence, sort multiple sets of vehicle boundary conditions based on the meshing order variation, and take the vehicle boundary condition with the largest meshing order variation as the target boundary condition, and determine the meshing order amplitude curve based on the target boundary condition;

[0034] S400: The meshing order amplitude curve is compared with the preset order threshold at each speed position. When the meshing order amplitude at any speed position exceeds the preset order threshold, the speed range corresponding to that speed position is determined as the gear squealing range. The gear NVH test results of the whole vehicle operating state are determined based on the gear squealing range.

[0035] Specifically, the speed encoder is a device used to collect real-time speed information of the gear system during operation, capturing changes in gear rotation speed. The housing vibration acceleration sensor, mounted on the gear electric drive assembly chassis housing, is used to collect housing vibration signals. These vibration signals reflect the intensity and characteristics of vibrations generated during gear meshing. The sound pressure sensor is used to collect ambient sound pressure signals during gear system operation; its multi-point arrangement allows for comprehensive capture of noise distribution at different locations. The gear system is driven by a speed scanning test condition, which involves continuous gear operation at different speeds, covering various speed ranges in actual vehicle operation. Speed, vibration, and sound pressure signals are collected synchronously to ensure temporal synchronization and avoid errors caused by asynchronous signal acquisition. After acquisition, the gear meshing frequency is determined based on the speed signal. The gear meshing frequency is the frequency of periodic excitation generated during gear meshing, closely related to gear speed, number of teeth, and transmission ratio. The speed signal allows for precise locking of the gear meshing frequency. The vibration and sound pressure signals are processed by order transformation. Order transformation is a processing method for rotating machinery signals. It can transform non-stationary vibration and sound pressure signals that change with rotational speed into stationary order spectra with the order as the abscissa. This clearly presents the changing law of gear meshing characteristics at different rotational speeds, thereby determining the gear meshing order spectrum at the corresponding rotational speed position. The gear meshing order spectrum reflects the amplitude distribution of the gear meshing order at different rotational speed positions, and can intuitively reflect the vibration and sound pressure characteristics during gear meshing. The stiffness adjustment range and damping simulation constraints are determined based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship. The stiffness adjustment range is determined by the actual stiffness parameters of the suspension structure in the vehicle, which determines the adjustable stiffness value range on the bench. The damping simulation constraints are based on the damping characteristics of the vehicle's suspension structure, which limits the damping adjustment on the bench. This allows for precise positioning of the actual installation state of the gear electric drive assembly in the vehicle, thereby reproducing the influence of different vehicle suspension stiffness and damping conditions on vibration transmission. This solves the problem that traditional bench testing does not consider the vehicle installation conditions and has only one boundary condition. Rotational speed scanning is repeated under different combinations of stiffness and damping. The vehicle boundary conditions are the combination of stiffness and damping conditions of the vehicle installation state. Multiple sets of order spectrum data can comprehensively cover various states that the vehicle may encounter, avoiding result deviations caused by single boundary condition testing and ensuring the stability of the test.

[0036] Understandably, after acquiring multiple sets of order spectrum data corresponding to vehicle boundary conditions, frequency band energy statistics are performed on all order spectrum data. Frequency band energy statistics calculate and statistically analyze the energy of different frequency bands in the order spectrum data, comprehensively sorting out the energy distribution characteristics of gear meshing-related signals under different vehicle boundary conditions. This focuses on the frequency band energy related to gear meshing. Sideband frequencies are auxiliary frequencies appearing around the gear meshing frequency; their amplitude changes can reflect the stability and fault characteristics of gear meshing. The amplitude sequence is a sequence formed by arranging the amplitudes corresponding to the gear meshing order and sideband frequencies at different speed positions in order of speed. This transforms the abstract order spectrum data into a quantified and comparative sequence, facilitating subsequent analysis of the impact of different vehicle boundary conditions on gear meshing characteristics. Based on the amplitude sequence, the change in meshing order under different vehicle boundary conditions is determined. The change in meshing order is the difference in the amplitude of the gear meshing order at the corresponding speed position under different vehicle boundary conditions, which can be quantified. This study investigates the influence of boundary conditions on gear meshing amplitude and provides objective quantitative evidence for test conditions. Multiple sets of vehicle boundary conditions are ranked based on the change in meshing order. The boundary condition with the largest change in meshing order is taken as the target boundary condition. The target boundary condition is the vehicle boundary condition that has the most significant impact on gear meshing characteristics and is also the test condition that best reflects the gear NVH response during actual vehicle operation. Locking in the test condition that best reflects the actual state of the vehicle ensures the accuracy and reliability of the test results and avoids the risk of bench testing being out of sync with the actual state of the vehicle, thus closely aligning with the vehicle's operating state. The meshing order amplitude curve is determined based on the target boundary condition. The meshing order amplitude curve is a curve plotted with speed as the abscissa and gear meshing order amplitude as the ordinate, based on the amplitude sequence under the target boundary condition. It can intuitively present the changing trend of gear meshing amplitude at different speed positions under the target boundary condition, providing a clear comparative basis for determining the whistling range. The gear meshing order amplitude curve is compared with a preset order threshold at each speed. The preset order threshold is set according to the vehicle NVH performance standard and is the upper limit of the allowable gear meshing order amplitude. It is the standard for determining whether the gear produces a whistling sound. The speed-by-speed comparison compares the meshing order amplitude corresponding to each speed position with the preset order threshold one by one, so as to accurately capture the gear NVH state at each speed position and avoid missing the speed range where whistling occurs. When the meshing order amplitude at any speed position exceeds the preset order threshold, the speed range corresponding to that speed position is determined as the gear whistling range. The gear whistling range is the speed range in which the gear produces whistling noise during operation. This clarifies the specific operating conditions under which gear whistling occurs, so that the final output gear NVH test results can truly reflect the gear NVH performance of the actual vehicle operation state, thereby ensuring the stability of the test and providing a reliable test basis for gear NVH performance optimization and vehicle noise control.

[0037] In some embodiments of this application, determining the gear meshing order spectrum at a corresponding rotational speed position includes: determining the gear input shaft rotational speed based on the rotational speed signal collected by the rotational speed encoder, determining the gear meshing frequency sequence based on the number of gear teeth and the transmission ratio, dividing the vibration signal and sound pressure signal into several sampling windows based on the time sequence, performing resampling processing in each sampling window, performing a fast Fourier transform on the resampling processing result, determining the order spectrum based on the order relationship corresponding to the gear input shaft rotational speed, extracting the gear meshing order and adjacent order components from the order spectrum, and determining the gear meshing order spectrum at the corresponding rotational speed position based on the rotational speed sequence.

[0038] Specifically, the gear input shaft speed is determined based on the speed signal collected by the speed encoder. The gear input shaft speed is the rotational speed of the input shaft in the gear electric drive assembly. The process of determining the rotational speed through the speed signal is lengthy and well-established, and will not be described here. The gear meshing frequency sequence is determined based on the number of gear teeth and the transmission ratio. The number of gear teeth is the number of teeth on the gear, and the transmission ratio is the ratio of the speed of the input shaft to the speed of the output shaft during gear transmission. The gear meshing frequency sequence is a sequence formed by arranging the gear meshing frequencies corresponding to different gear input shaft speeds in the order of speed change. This clarifies the gear meshing frequency at different speeds, providing a clear target for subsequently filtering gear meshing-related signals from vibration and sound pressure signals. Based on the time sequence, the vibration and sound pressure signals are divided into several sampling windows. The sampling window is an independent signal segment formed by dividing the continuously collected vibration and sound pressure signals into time segments. This transforms continuous, non-stationary vibration and sound pressure signals into multiple relatively stationary signal segments, avoiding processing errors caused by excessively long signals or large fluctuations. Resampling is performed in each sampling window. This resampling process resamples the signal within each window to adjust the sampling frequency, ensuring that the signal in each window matches the gear rotation cycle at the corresponding speed. This eliminates the signal frequency shift caused by changes in speed, ensures signal stability within each sampling window, and reduces signal distortion. The resampling results are then subjected to Fast Fourier Transform (FFT). FFT is a signal processing method that transforms time-domain signals (i.e., vibration signals and sound pressure signals that vary with time) into frequency-domain signals (i.e., signals that vary with frequency). By converting time-domain signals into frequency-domain signals, the amplitude corresponding to different frequencies in the signal can be clearly presented, ensuring the reliability of extracting gear meshing-related frequency features. The order relationship is the correspondence between the gear input shaft speed and the gear meshing order. The order spectrum is a spectrum reflecting the amplitude distribution corresponding to different orders. Compared with the frequency spectrum, the order spectrum can eliminate the influence of speed changes and accurately correspond to the rotation characteristics of the gear, avoiding interference caused by speed changes to signal analysis. This ensures that the order spectrum can truly reflect the gear meshing state. The gear meshing order and adjacent order components are extracted from the order spectrum. The adjacent order components are order signals located near the gear meshing order and related to the gear meshing process. Focusing on the order signals related to gear meshing can eliminate the interference of irrelevant order signals, ensuring the specificity of the extracted signals. The gear meshing order spectrum at the corresponding speed position is determined based on the speed sequence. That is, the extracted gear meshing order and adjacent order components are matched one-to-one with the corresponding gear input shaft speed to form a complete gear meshing order spectrum arranged in speed sequence. This ensures that each speed position has corresponding meshing order feature data, avoiding the risk of unclear meshing features caused by speed changes in signal processing and the existence of analysis errors. This further improves the accuracy and reliability of gear NVH testing.

[0039] In some embodiments of this application, determining the stiffness adjustment range and damping simulation constraints includes: determining the coordinates of the connection points of the suspension structure based on the installation position of the gear electric drive assembly bench in the vehicle, determining the bench installation reference position based on the connection point coordinates, setting stiffness components and damping adjustment components based on the bench installation reference position, determining several stiffness values ​​based on the combination of elastic elements of the stiffness components, determining the damping value corresponding to each stiffness value based on the damping coefficient of the damping element in the damping adjustment component, and determining the stiffness adjustment range and damping simulation constraints based on all stiffness values ​​and the corresponding damping values.

[0040] Specifically, the connection point coordinates of the suspension structure are determined based on the installation position of the gear electric drive assembly bench within the vehicle. The suspension structure is the structure in the vehicle used to connect the gear electric drive assembly to the body, serving to buffer vibrations and transmit forces. The connection point coordinates are the specific spatial coordinates of the connection points between the suspension structure and the gear electric drive assembly bench and the body. By accurately locating the actual connection position of the suspension structure within the vehicle, the risk of discrepancies between the suspension state and the actual vehicle condition due to connection position deviations is avoided. The bench installation reference position is determined on the gear electric drive assembly bench based on the connection point coordinates of the suspension structure, serving as the reference position for installing stiffness components and damping adjustment components. This unifies the installation reference of relevant components on the bench, ensuring the proper functioning of the stiffness components and damping adjustment components. The installation position of the components is consistent with the installation position of the vehicle's suspension structure. Stiffness components and damping adjustment components are set based on the bench mounting reference position. The stiffness component is used to adjust the stiffness characteristics and elasticity of the vehicle's suspension structure. It includes elastic elements of different specifications (such as springs, rubber elastic elements, elastic bushings, etc.), as well as mounting brackets, adjustment knobs, and other supporting structures for fixing and adjusting these elastic elements. Its overall function is to achieve precise adjustment of the stiffness characteristics of the vehicle's suspension structure through the combination of different elastic elements. The damping adjustment component is used to adjust the damping characteristics and vibration damping capability of the vehicle's suspension structure. It includes damping elements with different damping parameters (such as hydraulic dampers, viscous dampers, etc.). The damping components include gaskets, damping elements, and adjusting mechanisms (such as damping adjustment valves and adjusting bolts) for adjusting the damping coefficient of the damping elements. By adjusting the damping coefficient of the damping elements, the damping characteristics of the entire vehicle's suspension structure are determined. Specialized components are used to adjust the stiffness and damping function of the entire vehicle's suspension, achieving a replication of the vehicle's suspension characteristics. Furthermore, several stiffness values ​​are determined based on the combination of elastic elements in the stiffness component, which represents the combination of different elastic elements in the stiffness component (different combinations of elastic elements produce different elastic strengths). The stiffness value is a parameter that measures the elastic strength of the stiffness component, reflecting the component's ability to resist deformation. The damping value corresponding to each stiffness value is determined based on the damping coefficient of the damping elements in the damping adjustment component. The damping parameter measures the vibration attenuation capability of a damping element, reflecting the degree to which the element impedes vibration transmission. The corresponding damping value is a damping parameter matched to each stiffness value and conforms to the relationship between the stiffness and damping of the entire vehicle's suspension structure. By combining different elastic elements, various stiffness values ​​are obtained, covering the possible stiffness range of the vehicle's suspension structure. This ensures that subsequent tests can comprehensively demonstrate different stiffness conditions. Each stiffness value has a corresponding damping value, accurately determining the matching relationship between the stiffness and damping of the vehicle's suspension structure, avoiding test deviations caused by stiffness-damping mismatch. The stiffness adjustment range is the numerical range constituted by all determined stiffness values, clarifying the adjustable range of the stiffness components on the test bench. Damping simulation constraints are based on all corresponding damping values.The adjustment range of the damping adjustment component ensures that the test bench can comprehensively and accurately reflect different suspension states throughout the vehicle, further improving the accuracy and reliability of the test results.

[0041] In some embodiments of this application, when determining the order spectrum data corresponding to multiple sets of vehicle boundary conditions, the process includes: sequentially loading stiffness adjustment range and damping simulation constraints as each set of vehicle boundary conditions, performing speed scanning in each set of vehicle boundary conditions, determining the gear meshing order spectrum corresponding to the vehicle boundary conditions, numbering all gear meshing order spectra, and establishing order spectrum data containing the number, speed position, and gear meshing order spectrum.

[0042] Specifically, the stiffness adjustment range and damping simulation constraints are sequentially loaded as the boundary conditions for each group of vehicles. Sequential loading involves pairing each stiffness value within the stiffness adjustment range with its corresponding damping value (meeting the damping simulation constraints) one by one, and then loading them onto the stiffness and damping adjustment components of the gear electric drive assembly test bench. Each set of paired stiffness and damping combinations constitutes an independent set of vehicle boundary conditions, representing a single vehicle suspension state. This comprehensively covers all possible stiffness and damping matching situations of the vehicle. A speed scan is performed on each set of vehicle boundary conditions. The speed scan is the process of synchronously acquiring speed signals, vibration signals, and sound pressure signals and determining the meshing order spectrum. After loading the vehicle boundary conditions, it can cover various speed ranges of the gears in actual vehicle operation, ensuring that the test data is only affected by the current set of stiffness and damping combinations, thus truly reflecting the NVH response characteristics of the gears under suspension conditions. All gear meshing order spectra are numbered. Each number is a unique identifier assigned to the gear meshing order spectra corresponding to each set of vehicle boundary conditions. This identifier is used to distinguish the order spectra under different boundary conditions. The order spectrum data is formed by integrating the number of each order spectrum, all speed positions corresponding to that order spectrum, and the gear meshing order spectrum corresponding to each speed position, thereby forming structured data and further improving the accuracy and reliability of the test results.

[0043] In some embodiments of this application, the extraction of the amplitude sequence of gear meshing order and sideband frequency includes: determining the order interval where the gear meshing order is located in the order spectrum data, setting order sideband intervals on both sides of the order interval, determining the order energy value at the corresponding rotational speed position based on the order amplitude in the order interval and the sideband interval, determining the order energy sequence based on the rotational speed sequence and each order energy value, and determining the amplitude sequence of gear meshing order and sideband frequency according to the order energy sequence.

[0044] Specifically, the order interval is the range of orders surrounding the gear meshing order, encompassing all relevant signals of that order. It is used to clearly define the signal distribution area of ​​the gear meshing order, accurately pinpoint the range of gear meshing-related signals, and avoid interference from irrelevant order signals. Order sideband intervals are set on both sides of the order interval. These sideband intervals are located on either side of the order interval containing the order signals corresponding to the sideband frequencies, thus completely covering the gear meshing order and surrounding related sideband signals. This avoids missing information reflecting gear meshing stability and ensures comprehensive extraction of meshing features. Based on the order amplitudes within the order interval and sideband intervals, the order energy value at the corresponding speed position is determined. The order energy value is the energy magnitude comprehensively reflected by all order amplitudes within the order interval and sideband intervals. The order energy value quantifies the intensity of gear meshing and sideband signals at that speed position, transforming dispersed order amplitudes into a unified energy quantification index, facilitating subsequent analysis and comparison, and reducing the bias caused by a single amplitude. The order energy sequence is determined based on the rotational speed order and the energy values ​​of each order. This sequence arranges the order energy values ​​corresponding to each rotational speed position in ascending order of speed, clearly showing the variation of gear meshing energy at different speeds. The order energy value itself is determined based on the order amplitude within the order interval and the order sideband interval where the gear meshing order is located; essentially, it is the comprehensive energy representation of all order amplitudes within these two intervals. Therefore, when determining the amplitude sequence, it is necessary to first reverse-correlate the order energy value corresponding to each rotational speed position in the order energy sequence to its corresponding order interval and order sideband interval. Then, extract the amplitude corresponding to the gear meshing order and the amplitude corresponding to the sideband frequency within the order sideband interval from this order energy value. Finally, arrange the sideband frequency amplitude corresponding to each rotational speed position one by one according to the rotational speed order to obtain the amplitude sequence of gear meshing order and sideband frequency. The quantized order energy is converted into an amplitude sequence that directly corresponds to the gear meshing order and sideband frequency, enabling accurate extraction and processing of signal features and further improving the reliability of gear NVH test results.

[0045] In some embodiments of this application, determining the target boundary conditions includes: extracting the engagement order amplitude corresponding to different vehicle boundary conditions, taking the difference between each engagement order amplitude as the engagement order change, normalizing all engagement order changes, sorting the normalization results, and determining the target boundary conditions based on the sorting results.

[0046] Specifically, the process involves extracting the meshing order amplitudes corresponding to different vehicle boundary conditions. This means retrieving the meshing order amplitudes at each speed position within the established amplitude sequences of gear meshing orders and sideband frequencies for each set of vehicle boundary conditions. The meshing order amplitude reflects the magnitude of the gear meshing order at that position, indicating the vibration intensity and sound pressure level parameters generated during gear meshing at a given speed. The gear meshing characteristics under different vehicle boundary conditions are extracted, and the differences between the amplitudes of each meshing order are used as the meshing order variation. This variation represents the difference in gear meshing order amplitudes at the same speed position under different vehicle boundary conditions, reflecting the degree to which changes in vehicle boundary conditions affect the gear meshing order amplitude. All meshing order variations are then normalized. Normalization converts meshing order variations of different magnitudes and ranges into values ​​within a unified standard range, eliminating comparison biases caused by differences in numerical magnitudes and avoiding discrepancies due to variations in numerical magnitudes. This leads to distorted sorting. By sorting the normalized results and arranging the standardized meshing order changes in an orderly manner according to their numerical values, it is possible to clearly distinguish the strength of the influence of different vehicle boundary conditions on the gear meshing order amplitude. The target boundary condition is the vehicle boundary condition that has the greatest impact on the gear meshing order amplitude and can best expose gear NVH problems. It is also the test boundary condition that is closest to the actual operating state of the vehicle. Using the target boundary condition as the target boundary condition avoids the risk of traditional bench testing boundary conditions being too singular and unable to match the actual state of the vehicle, thus improving the reliability of gear NVH test results.

[0047] In some embodiments of this application, determining the meshing order amplitude curve includes: determining a target amplitude sequence based on target boundary conditions, and determining the corresponding meshing order amplitude curve based on the target amplitude sequence.

[0048] Specifically, the target amplitude sequence is determined based on the target boundary conditions. The target amplitude sequence is the amplitude sequence that uniquely corresponds to the target boundary conditions and reflects the gear meshing characteristics under those boundary conditions. As the test boundary conditions that have the greatest impact on the gear meshing order amplitude and are closest to the actual operating state of the vehicle, the target boundary conditions also have an amplitude sequence that best reflects the NVH response of the vehicle gears. This lays the data foundation for drawing accurate meshing order amplitude curves and ensures that the meshing order amplitude curves can truly reflect the gear meshing amplitude change characteristics under the actual operating state of the vehicle. The meshing order amplitude curve is a planar coordinate system established by plotting the gear's rotational speed on the x-axis and the gear meshing order amplitude on the y-axis. The curve is plotted by drawing the data in the target amplitude sequence according to their corresponding relationships. The meshing order amplitude curve can intuitively and clearly present the changing trend of the gear meshing order amplitude at different rotational speeds under the target boundary conditions. It transforms the abstract and scattered amplitude sequence data into an intuitive and continuous curve, clearly showing the changing law of gear meshing amplitude at different rotational speeds, and further improving the reliability of the entire testing process.

[0049] In some embodiments of this application, when performing position comparison by rotational speed, the method includes: obtaining the amplitude in the meshing order amplitude curve based on the rotational speed sequence, and comparing it point by point with the corresponding preset order threshold. When the amplitude of the continuous rotational speed position is greater than the corresponding preset order threshold, the gear squealing interval is determined based on the continuous rotational speed position.

[0050] In some embodiments of this application, when determining the gear NVH test results of the vehicle's operating state, the method includes: recording the speed range corresponding to the gear squealing interval, and outputting the corresponding gear NVH test results based on the speed range.

[0051] Specifically, the amplitude values ​​corresponding to each speed position on the meshing order amplitude curve are extracted sequentially. Then, each amplitude value is compared point-by-point with its corresponding preset order threshold. The preset order threshold is an upper limit set in advance based on vehicle NVH performance requirements, actual vehicle ride comfort, and relevant evaluation standards to determine whether gears produce squealing. By comparing the amplitude value at each speed position with the preset order threshold one-to-one, it is determined whether the amplitude exceeds the limit at that speed position. This achieves detection across the entire speed range, ensuring accurate verification of the gear meshing state at each speed position and avoiding omissions of squealing risk points. When the amplitude values ​​at consecutive speed positions are all greater than the corresponding preset order threshold, then based on the continuous rotation... The speed position determines the gear squealing range. Continuous speed positions are interconnected and uninterrupted coordinate points. Using the continuous speed determination method can eliminate single-point abnormal interference caused by instantaneous signal fluctuations and accidental acquisition errors, ensuring that the gear squealing range can truly reflect the squealing conditions of the gear in actual operation. The gear squealing range is the speed range in which the gear actually produces squealing noise due to excessive meshing excitation during operation. When determining the gear NVH test results for the whole vehicle's operating state, the speed range corresponding to the gear squealing range is recorded. The gear NVH test results are determined based on the size of the speed range corresponding to the gear squealing range. The bench test results can closely match the actual operating state of the whole vehicle, ensuring the stability of the test results.

[0052] In summary, the beneficial effects of this invention are as follows: By arranging corresponding sensors on the gear electric drive assembly test bench and synchronously collecting speed signals, vibration signals, and sound pressure signals, a comprehensive and time-synchronized data foundation can be provided for gear NVH characteristic analysis, avoiding analysis errors caused by signal loss or asynchrony. Furthermore, by performing order transformation processing on the signals to obtain the gear meshing order spectrum, and combining the installation position of the gear electric drive assembly in the vehicle with the suspension connection relationship to determine the stiffness adjustment range and damping simulation constraints, the influence of the stiffness and damping characteristics of the vehicle's suspension structure on the vibration transmission path and natural frequency can be reproduced on the test bench, avoiding the need for test bench analysis. To mitigate the risks of relying on singular test boundary conditions and being disconnected from the vehicle's installation status, this paper performs frequency band energy statistics, amplitude sequence extraction, and sorting of meshing order changes on order spectrum data under multiple vehicle boundary conditions. This allows for the selection of target boundary conditions that have the greatest impact on gear NVH response, thereby accurately matching the gear excitation response characteristics during actual vehicle operation. By comparing the meshing order amplitude curve corresponding to the target boundary condition with a preset order threshold at each speed to determine the gear squealing range, the paper solves the problems of traditional bench testing failing to accurately predict vehicle gear squealing and inconsistent test data with actual vehicle performance, thus improving the reliability of gear NVH test results.

[0053] In another preferred embodiment based on the above embodiments, see [reference] Figure 2As shown, this embodiment provides a testing system for the NVH performance of gears in new energy vehicles, which is used to apply a testing method for the NVH performance of gears in new energy vehicles, including:

[0054] The acquisition unit is configured to synchronously acquire rotation speed signals, vibration signals, and sound pressure signals based on rotation speed scanning conditions.

[0055] The analysis unit is configured to determine the gear meshing frequency based on the rotational speed signal, and to perform order transformation processing on the vibration signal and sound pressure signal to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, it determines the stiffness adjustment range and damping simulation constraints, and repeatedly performs rotational speed scanning under different combinations of stiffness and damping conditions to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions.

[0056] The processing unit is configured to perform frequency band energy statistics on all order spectrum data, extract the amplitude sequence of gear meshing order and sideband frequency, determine the meshing order change amount under different vehicle boundary conditions based on the amplitude sequence, sort multiple sets of vehicle boundary conditions based on the meshing order change amount, and take the vehicle boundary condition with the largest meshing order change amount as the target boundary condition, and determine the meshing order amplitude curve based on the target boundary condition.

[0057] The test unit is configured to compare the meshing order amplitude curve with a preset order threshold at each speed. When the meshing order amplitude at any speed exceeds the preset order threshold, the speed range corresponding to that speed position is determined as the gear squealing range. The gear NVH test results of the whole vehicle operating state are determined based on the gear squealing range.

[0058] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

Claims

1. A test method for NVH performance of gears in new energy vehicles, characterized in that, include: A speed encoder, a housing vibration acceleration sensor, and a sound pressure sensor are arranged on the gear electric drive assembly bench to synchronously acquire speed signals, vibration signals, and sound pressure signals based on the speed scanning condition. Based on the rotational speed signal, the gear meshing frequency is determined, and the vibration signal and sound pressure signal are processed by order transformation to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, the stiffness adjustment range and damping simulation constraints are determined. The rotational speed is repeatedly scanned under different combinations of stiffness and damping to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions. Frequency band energy statistics are performed on all order spectrum data, and the amplitude sequences of gear meshing order and sideband frequency are extracted. Based on the amplitude sequences, the meshing order variation under different vehicle boundary conditions is determined. Based on the meshing order variation, multiple sets of vehicle boundary conditions are sorted, and the vehicle boundary condition with the largest meshing order variation is taken as the target boundary condition. Based on the target boundary condition, the meshing order amplitude curve is determined. The engagement order amplitude curve is compared with a preset order threshold at each speed position. When the engagement order amplitude at any speed position exceeds the preset order threshold, the speed range corresponding to that speed position is determined as the gear squealing range. The gear NVH test results of the whole vehicle operating state are determined based on the gear squealing range.

2. The test method for NVH performance of gears in new energy vehicles according to claim 1, characterized in that, When determining the gear meshing order spectrum at the corresponding rotational speed position, the process includes: determining the gear input shaft rotational speed based on the rotational speed signal collected by the rotational speed encoder, determining the gear meshing frequency sequence based on the number of gear teeth and the transmission ratio, dividing the vibration signal and sound pressure signal into several sampling windows based on the time sequence, performing resampling processing in each sampling window, performing a fast Fourier transform on the resampling processing result, determining the order spectrum based on the order relationship corresponding to the gear input shaft rotational speed, extracting the gear meshing order and adjacent order components from the order spectrum, and determining the gear meshing order spectrum at the corresponding rotational speed position based on the rotational speed sequence.

3. The test method for NVH performance of gears in new energy vehicles according to claim 2, characterized in that, When determining the stiffness adjustment range and damping simulation constraints, the process includes: determining the coordinates of the connection points of the suspension structure based on the installation position of the gear electric drive assembly bench in the vehicle, determining the bench installation reference position based on the connection point coordinates, setting stiffness components and damping adjustment components based on the bench installation reference position, determining several stiffness values ​​based on the combination of elastic elements of the stiffness components, determining the damping value corresponding to each stiffness value based on the damping coefficient of the damping element in the damping adjustment component, and determining the stiffness adjustment range and damping simulation constraints based on all stiffness values ​​and the corresponding damping values.

4. The test method for NVH performance of gears in new energy vehicles according to claim 3, characterized in that, When determining the order spectrum data corresponding to multiple sets of vehicle boundary conditions, the process includes: sequentially loading the stiffness adjustment range and damping simulation constraints as each set of vehicle boundary conditions, performing a speed scan in each set of vehicle boundary conditions, determining the gear meshing order spectrum corresponding to the vehicle boundary conditions, numbering all gear meshing order spectra, and establishing order spectrum data containing the number, speed position, and gear meshing order spectrum.

5. The test method for NVH performance of gears in new energy vehicles according to claim 4, characterized in that, When extracting the amplitude sequence of gear meshing order and sideband frequency, the process includes: determining the order interval where the gear meshing order is located in the order spectrum data, setting order sideband intervals on both sides of the order interval, determining the order energy value at the corresponding rotational speed position based on the order amplitude in the order interval and sideband interval, determining the order energy sequence based on the rotational speed sequence and each order energy value, and determining the amplitude sequence of gear meshing order and sideband frequency according to the order energy sequence.

6. The test method for NVH performance of gears in new energy vehicles according to claim 5, characterized in that, When determining the target boundary conditions, the following steps are taken: extracting the engagement order amplitude corresponding to different vehicle boundary conditions, taking the difference between the engagement order amplitudes as the engagement order change, normalizing all engagement order changes, sorting the normalization results, and determining the target boundary conditions based on the sorting results.

7. The test method for NVH performance of gears in new energy vehicles according to claim 6, characterized in that, Determining the engagement order amplitude curve includes: determining a target amplitude sequence based on the target boundary conditions, and determining the corresponding engagement order amplitude curve based on the target amplitude sequence.

8. A test method for NVH performance of gears in new energy vehicles according to claim 7, characterized in that, When performing position comparison by rotational speed, the process includes: obtaining the amplitude in the meshing order amplitude curve based on the rotational speed sequence, and comparing it point by point with the corresponding preset order threshold. When the amplitude of the continuous rotational speed position is greater than the corresponding preset order threshold, the gear squealing interval is determined based on the continuous rotational speed position.

9. The test method for NVH performance of gears in new energy vehicles according to claim 8, characterized in that, When determining the gear NVH test results for the overall vehicle operating status, the process includes: recording the speed range corresponding to the gear squealing interval, and outputting the corresponding gear NVH test results based on the speed range.

10. A testing system for the NVH performance of gears in new energy vehicles, used to apply the testing method for the NVH performance of gears in new energy vehicles as described in any one of claims 1-9, characterized in that, include: The acquisition unit is configured to synchronously acquire rotation speed signals, vibration signals, and sound pressure signals based on rotation speed scanning conditions. The analysis unit is configured to determine the gear meshing frequency based on the rotational speed signal, and to perform order transformation processing on the vibration signal and sound pressure signal to determine the gear meshing order spectrum at the corresponding rotational speed position. Based on the installation position of the gear electric drive assembly bench in the vehicle and the suspension connection relationship, it determines the stiffness adjustment range and damping simulation constraints, and repeatedly performs rotational speed scanning under different combinations of stiffness and damping conditions to determine the order spectrum data corresponding to multiple sets of vehicle boundary conditions. The processing unit is configured to perform frequency band energy statistics on all order spectrum data, extract the amplitude sequence of gear meshing order and sideband frequency, determine the meshing order variation under different vehicle boundary conditions based on the amplitude sequence, sort multiple sets of vehicle boundary conditions based on the meshing order variation, take the vehicle boundary condition with the largest meshing order variation as the target boundary condition, and determine the meshing order amplitude curve based on the target boundary condition. The test unit is configured to compare the meshing order amplitude curve with a preset order threshold at each rotational speed. When the meshing order amplitude at any rotational speed exceeds the preset order threshold, the rotational speed range corresponding to that rotational speed position is determined as the gear squealing range. Based on the gear squealing range, the gear NVH test result of the vehicle's operating state is determined.

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