Vehicle transmission system gear noise online diagnosis method and system and computer readable storage medium

Abstract

The invention provides a vehicle transmission system gear noise online diagnosis method and system and a computer readable storage medium. The vehicle transmission system gear noise online diagnosis method comprises the steps of obtaining a series order set H and a gear meshing frequency of gears in a transmission system when a vehicle runs at a certain gear; a noise sound pressure signal function SP (t) in the driving process of the vehicle at the gear is obtained, a vehicle rotating speed signal function T (tacho) in time synchronization with the noise sound pressure signal SP (t) is obtained, SP (t), T (tacho), H and the gear meshing frequency are processed, and a power density function Lh (w) of the corresponding gear is obtained; calculating order component energy A according to the power density function Lh (w) of the corresponding gear; calculating critical bandwidth energy B according to the power density function Lh (w) of the corresponding gear; calculating dark noise energy C, wherein C = B-A; calculating a difference value between a gear order component energy conversion component and a dark noise energy conversion component; and judging whether the noise is easily perceived by human ears. According to the invention, the gear with noise problem can be quickly positioned.

Description

Technical Field

[0001] The present invention relates to the technical field of noise diagnosis, and in particular to an online diagnosis method, system and computer-readable storage medium for vehicle transmission system gear noise. Background Art

[0002] Four-wheel drive off-road vehicles typically have complex chassis transmission systems, with numerous gear reducers along the transmission path. Gear noise is often a prominent issue during driving. Existing methods for diagnosing gear noise typically rely on objective indicators of sound pressure levels on a test bench, or empirical data from gearbox vibrations to determine if gear noise is prominent. Furthermore, existing methods for diagnosing gear noise prominently rely on objective indicators of general sound pressure levels or gearbox vibrations. This method only reflects the overall sound level and cannot quickly pinpoint the gear with the noise issue.

[0003] Therefore, it is necessary to improve the existing online diagnosis method of vehicle transmission system gear noise in order to quickly locate the gear with noise problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a vehicle transmission system gear noise online diagnosis method, system and computer-readable storage medium to solve the problem that the existing vehicle transmission system gear noise online diagnosis method, system, system and computer-readable storage medium cannot quickly locate gears with noise problems.

[0005] To solve the above technical problems, the present invention provides an online diagnosis method for gear noise in a vehicle transmission system, comprising: obtaining a series order set H of gears in the transmission system and a gear meshing frequency when the vehicle is traveling in a certain gear; obtaining a noise sound pressure signal function SP(t) of the vehicle during the driving process in the gear, and obtaining a vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t); and processing the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the series order set H of the gears, and the gear meshing frequency to obtain a power density function L of the corresponding gear. h (w); According to the power density function L of the corresponding gear h (w) Calculate the order component energy A; according to the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B; calculate the dark noise energy C, C=BA; calculate the difference between the gear order component energy converted into decibels and the dark noise energy converted into decibels; and determine whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0006] Optionally, obtaining the series order set H and gear meshing frequency of the gears in the vehicle transmission system includes: obtaining relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and the wheel rolling radius; calculating the gear meshing frequency based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and the wheel rolling radius; calculating the gear meshing order based on the relevant parameters of the gears in the vehicle transmission system; and establishing the series order set H of the gears in the vehicle transmission system.

[0007] Optionally, the gear meshing frequency is calculated based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and the wheel rolling radius using the following formula: in, f i - gear meshing frequency; r i - Speed ​​of the gear shaft; n i - number of gear teeth; V- vehicle speed; R- wheel rolling radius; i i - axle-to-wheel transmission ratio; The gear meshing order is calculated based on the relevant parameters of the gears in the vehicle transmission system using the following formula: in, h i - gear meshing order, n i - number of gear teeth, I i -The gear shaft's transmission ratio relative to the engine, and the gear series order set .

[0008] Optionally, the order component energy A is calculated using the following formula: Among them, F N is the center noise frequency.

[0009] Optionally, the critical bandwidth energy B is calculated using the following formula: Among them, F N is the center noise frequency, F C Critical bandwidth of the center frequency, Among them, F C Calculated by the following formula: .

[0010] Optionally, the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels is calculated using the following formula: in, It is the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0011] Optionally, judging whether the noise is easily perceptible to the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels includes: like If it is less than 0, it means that C is greater than A, indicating that the background noise is greater than the gear order noise and the gear noise is masked. At this time, it can be considered that the gear pair order noise will not be heard. is less than a predetermined threshold, which can be set as QdBA, i.e. If the value is less than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively small. Within the threshold Q range, it can be considered that the gear order noise cannot be distinguished from the background noise by the normal human hearing sensitivity. If it is greater than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively large. At this time, it can be considered that the gear order noise can be distinguished from the background noise with the normal hearing sensitivity of the human ear.

[0012] Optionally, the noise pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency are processed to obtain the power density function L of the corresponding gear h (w) includes: performing short-time Fourier transform on the collected noise pressure signal function SP(t) to obtain a three-dimensional matrix Q(w) of time, noise frequency and sound self-power spectrum amplitude; converting the three-dimensional matrix into a three-dimensional matrix L(w) of engine speed, noise frequency and sound self-power spectrum amplitude according to the engine speed corresponding to the moment; using the engine speed signal function T(tacho) as the state vector, establishing the state matrix of the Kalman filter to describe the law of engine speed change over time; according to the gear meshing frequency corresponding to the order of the gear in H, the corresponding power spectrum density amplitude can be searched in L(w), and the observation matrix is ​​established with the corresponding power spectrum density amplitude; using the Kalman filter for harmonic tracking, real-time filtering of the L(w) curve can be performed to obtain the power density function L of the corresponding gear. h (w).

[0013] The present invention further provides a vehicle transmission system gear noise online diagnosis system for implementing the above-mentioned vehicle transmission system gear noise online diagnosis method, comprising: An input module for obtaining a series order set H and a gear meshing frequency of a gear in a vehicle transmission system; an acquisition module, configured to acquire a noise sound pressure signal function SP(t) of a vehicle while the vehicle is traveling in a certain gear, and to acquire a vehicle speed signal function T(tacho) that is time-synchronized with the noise sound pressure signal SP(t); The calculation module is used to process the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency to obtain the power density function L of the corresponding gear. h (w), and is used to calculate the power density function L of the corresponding gear h (w) Calculate the order component energy A, which is used to calculate the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B, which is used to calculate the dark noise energy C, C = BA; A conversion comparison module, used for calculating the difference between the order component energy converted into decibels and the dark noise energy converted into decibels; The judgment module is used to judge whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0014] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0015] The present invention provides a vehicle transmission system gear noise online diagnosis method, system and computer-readable storage medium, which have the following beneficial effects: By calculating the order component energy A and the critical width bandwidth energy B, calculating the dark noise energy C, and calculating the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels, it is possible to determine whether the gear order noise is masked by the background noise, and whether the gear order noise that is not masked by the background noise can be perceived by the human ear, thereby determining whether the vehicle has a prominent gear noise problem; because before determining whether the vehicle has a prominent gear noise problem, the order component energy A and the critical bandwidth energy B generated by the gear of the corresponding order are calculated, the noise perceived by the human ear can be matched with the corresponding gear, thereby finding the gear with a prominent noise problem, thereby achieving the effect of quickly locating the gear noise problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the ∆Lu curve of the gear at different vehicle speeds in the embodiment of the present invention; Figure 2 is the three-dimensional matrix L in the embodiment of the present invention h(w) colormap; Figure 3 is a schematic diagram of the gear transmission principle in a vehicle transmission system according to an embodiment of the present invention; Figure 4 is a graph of the noise sound pressure signal function SP(t) in an embodiment of the present invention; Figure 5 is a graph of a vehicle speed signal function T(tacho) according to an embodiment of the present invention; Figure 6 is the power density function L obtained in the embodiment of the present invention h Schematic diagram of (w); Figure 7 is a colormap diagram of the three-dimensional matrix Q(w) in an embodiment of the present invention; Figure 8 is a colormap diagram of the three-dimensional matrix L(w) in an embodiment of the present invention; Figure 9 is a graph of order component energy A in an embodiment of the present invention; Figure 10 is a graph of critical bandwidth energy B in an embodiment of the present invention; Figure 11 is a graph of dark noise energy C in an embodiment of the present invention; Figure 12 3 is a graph showing the difference between the gear order component energy converted into decibels and the dark noise energy converted into decibels in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following is a further description of specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0018] This embodiment provides an online diagnosis method for gear noise in a vehicle transmission system, comprising: Obtain the series order set H and gear meshing frequency of the gears in the transmission system when the vehicle is traveling in a certain gear; Obtain the noise sound pressure signal function SP(t) of the vehicle during driving in this gear, and obtain the vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t). Then process the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency to obtain the power density function L of the corresponding gear. h (w); According to the power density function L of the corresponding gear h (w) Calculate the order component energy A; According to the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B; Calculate the dark noise energy C, C=BA; Calculate the difference between the gear order component energy converted into decibels and the dark noise energy converted into decibels; Whether the noise is easily perceived by the human ear is determined based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0019] By calculating the order component energy A and the critical width bandwidth energy B, calculating the dark noise energy C, and calculating the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels, it is possible to determine whether the gear order noise is masked by the background noise, and whether the gear order noise that is not masked by the background noise can be perceived by the human ear, thereby determining whether the vehicle has a prominent gear noise problem; because before determining whether the vehicle has a prominent gear noise problem, the order component energy A and the critical bandwidth energy B generated by the gear of the corresponding order are calculated, the noise perceived by the human ear can be matched with the corresponding gear, thereby finding the gear with a prominent noise problem, thereby achieving the effect of quickly locating the gear noise problem.

[0020] The process of obtaining the gear order set H and the gear meshing frequency in the vehicle transmission system includes: Obtain relevant parameters of gears in the vehicle transmission system, as well as vehicle speed and wheel rolling radius; Calculate the gear meshing frequency based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and wheel rolling radius; Calculate the gear meshing order based on the relevant parameters of the gears in the vehicle transmission system; Establish the series order set H of gears in the vehicle transmission system.

[0021] Among them, the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency are processed to obtain the power density function L of the corresponding gear h (w) include: Perform short-time Fourier transform on the collected noise sound pressure signal function SP(t) to obtain a three-dimensional matrix Q(w) of time, noise frequency and sound autopower spectrum amplitude; According to the engine speed corresponding to the moment, the three-dimensional matrix is ​​converted into a three-dimensional matrix L(w) of engine speed, noise frequency, and sound autopower spectrum amplitude; The engine speed signal function T(tacho) is used as the state vector to establish the state matrix of the Kalman filter to describe the law of engine speed change over time; According to the gear meshing frequency corresponding to the gear order in H, the corresponding power spectrum density amplitude can be searched in L(w), and the observation matrix is ​​established with the corresponding power spectrum density amplitude; The Kalman filter is used for harmonic tracking and the L(w) curve is filtered in real time to obtain the power density function L of the corresponding gear. h (w).

[0022] Where SP(t) is the function of the noise pressure signal and time. T(tacho) is the function of the engine speed and time. L(w) is a three-dimensional matrix of engine speed, noise frequency and sound autopower spectrum amplitude. h (w) is a function of the corresponding gear order noise autopower spectrum amplitude and noise frequency.

[0023] In this embodiment, obtaining the relevant parameters of the gears in the vehicle transmission system includes obtaining the number of teeth of the gears in the vehicle transmission system, the rotational speed of the shaft on which the gears are located, the transmission ratio from the shaft on which the gears are located to the wheels, and the transmission ratio of the gears on the shaft relative to the engine.

[0024] The gears generally include engine gears (crankshaft gears, oil pump gears, balance shaft gears, valve timing gears, etc.), transmission gears (first shaft gears, second shaft i-gear gears, intermediate shaft i-gear gears, etc., where i represents the transmission gear position), transfer case gears (driving gears, driven gears), final reducer gears (driving gears, driven gears), and wheel-side reducer gears (driving gears, driven gears).

[0025] In this embodiment, the gear meshing frequency is calculated based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and the wheel rolling radius using the following formula: in, f i - gear meshing frequency; r i - Speed ​​of the gear shaft; n i - number of gear teeth; V- vehicle speed; R- wheel rolling radius; i i - Axle to wheel ratio.

[0026] The gear meshing order is calculated based on the relevant parameters of the gears in the vehicle transmission system using the following formula: in, h i- gear meshing order, n i - number of gear teeth, I i -The gear ratio of the shaft on which the gear is located relative to the engine.

[0027] Series order set of gears .

[0028] When obtaining the noise sound pressure signal function SP(t) during vehicle use and the vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t), a sound collector is arranged at the ear of the vehicle occupant.

[0029] The order component energy A is calculated using the following formula: Among them, F N is the center noise frequency.

[0030] The critical bandwidth energy B is calculated by the following formula: Among them, F N is the center noise frequency, F C Critical bandwidth of the center frequency.

[0031] Among them, F C Calculated by the following formula: According to psychoacoustic theory, when the ratio of single-frequency noise to background noise is relatively small, human hearing sensitivity cannot distinguish single-frequency noise from background noise. This embodiment innovatively introduces the concept of dark noise to describe the continuous noise that is hidden behind gear order noise and is masked, making it difficult to hear.

[0032] The difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels is calculated using the following formula: in, It is the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0033] Judging whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels includes: like If it is less than 0, it means that C is greater than A, indicating that the background noise is greater than the gear order noise and the gear noise is masked. At this time, it can be considered that the gear pair order noise will not be heard. is less than a predetermined threshold, which can be set as QdBA, i.e. If the value is less than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively small. Within the threshold Q range, it can be considered that the gear order noise cannot be distinguished from the background noise by the normal human hearing sensitivity. If it is greater than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively large. At this time, it can be considered that the gear order noise can be distinguished from the background noise with the normal hearing sensitivity of the human ear.

[0034] Preferably, the vehicle transmission system gear noise online diagnosis method further includes: The vehicle is selected to drive on a straight road in each gear (including gearbox and transfer case gears), and the noise sound pressure signal function SP(t) and vehicle speed signal function T(tacho) under slow acceleration conditions are used. And calculate the ∆Lu curve of the gear at different gears, that is, different vehicle speeds, and store it, where u is the gear number, as follows Figure 1 As shown, Figure 1 is the ∆Lu curve of the gear at different vehicle speeds in the embodiment of the present invention.

[0035] The vehicle transmission system gear noise online diagnosis method further includes: Select the three-dimensional coordinate vectors of engine speed, noise frequency, and sound autopower spectrum amplitude to make a three-dimensional matrix L h The colormap of (w) is drawn by the embedded system and then displayed on the monitor in real time.

[0036] In this way, the gear noise characteristics of the transmission system can be intuitively identified as follows Figure 2 , Figure 2 is the three-dimensional matrix L in the embodiment of the present invention h The colormap diagram of (w) can correspond to the order set in the set H, and the series colormap-u diagram can be stored as the experimental data record.

[0037] Among them, the following method can be used to identify the corresponding gear noise order and gear according to the colormap: If you track the speed during an acceleration test, the rotating machinery analysis module can usually automatically mark the order line (that is, the ratio of the frequency of noise occurrence to the engine rotation speed).

[0038] The gear noise order and gear can also be calculated as follows: Take any point on the gear noise order line, read the horizontal and vertical coordinates (i.e. frequency and engine speed), divide the frequency by the speed, and you can get the order h corresponding to this gear noise. i, you can get the gear number by looking up the table in set H.

[0039] The following describes the online diagnosis method for vehicle transmission system gear noise using the third gear of the transmission as an example.

[0040] First, refer to Figure 3 , Figure 3 This is a diagram of the gear transmission principle in the vehicle transmission system according to an embodiment of the present invention. The order set H and gear meshing frequency of the third gear of the transmission when the vehicle is traveling in third gear are obtained. Since the number of teeth of the driving gear of the meshing gears of the first and second shafts is 24, and since the speed of the first shaft of the transmission is the same as that of the engine, the order h of this pair of gears relative to the engine can be calculated. i That's 24.

[0041] Secondly, obtain the noise sound pressure signal function SP(t) of the vehicle during the gear shift, and obtain the vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t). Figure 4 , Figure 4 is a graph of the noise sound pressure signal function SP(t) in the embodiment of the present invention, and the obtained vehicle speed signal function T(tacho) is referenced Figure 5 , Figure 5 is a graph of the vehicle speed signal function T(tacho) in an embodiment of the present invention.

[0042] Then, the noise pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency are processed to obtain the power density function L of the corresponding gear. h (w). Where, reference Figure 6 , Figure 6 is the power density function L obtained in the embodiment of the present invention h (w) Schematic diagram, the power density function L of the gear of this order can be obtained by harmonic tracking and filtering the 24th order gear noise signal h (w).

[0043] Specifically, the collected noise sound pressure signal function SP(t) is subjected to short-time Fourier transform to obtain a three-dimensional matrix Q(w) of time, noise frequency and sound autopower spectrum amplitude, where Q(w) can be represented by a colormap. Figure 7 , Figure 7 This is a colormap of the three-dimensional matrix Q(w) in the embodiment of the present invention. The three-dimensional matrix is ​​converted into a three-dimensional matrix L(w) of engine speed, noise frequency, and sound autopower spectrum amplitude according to the corresponding engine speed at the time. L(w) can be represented by a colormap. Figure 8 , Figure 8 It is a colormap diagram of the three-dimensional matrix L(w) in an embodiment of the present invention.

[0044] Then, according to the power density function L of the corresponding gear h (w) Calculate the order component energy A, where the curve of A is referenced Figure 9 , Figure 9 3 is a graph of order component energy A in an embodiment of the present invention.

[0045] Then, according to the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B, where the curve of B is referenced Figure 10 , Figure 10 is a graph of critical bandwidth energy B in an embodiment of the present invention.

[0046] After that, calculate the dark noise energy C, C=BA, where the curve of C is referenced Figure 11 , Figure 11 is a graph of dark noise energy C in an embodiment of the present invention.

[0047] Then, the difference between the gear order component energy converted into decibels and the dark noise energy converted into decibels is calculated, where the difference curve is referenced Figure 12 , Figure 12 3 is a graph showing the difference between the gear order component energy converted into decibels and the dark noise energy converted into decibels in an embodiment of the present invention.

[0048] This embodiment also provides an online diagnosis system for gear noise in a vehicle transmission system, comprising: an input module for obtaining a series order set H of gears in the transmission system and a gear meshing frequency when the vehicle is traveling in a certain gear; an acquisition module for obtaining a noise sound pressure signal function SP(t) of the vehicle during the vehicle traveling in the gear, and a vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t); a calculation module for processing the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the series order set H of the gears, and the gear meshing frequency to obtain a power density function L of the corresponding gear. h (w), and is used to calculate the power density function L of the corresponding gear h (w) Calculate the order component energy A, which is used to calculate the power density function L of the corresponding gear h (w) calculating the critical bandwidth energy B, which is used to calculate the dark noise energy C, where C=BA; a conversion comparison module, which is used to calculate the difference between the order component energy converted into decibels and the dark noise energy converted into decibels; and a judgment module, which is used to judge whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

[0049] This embodiment further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0050] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A method for online diagnosis of gear noise in a vehicle transmission system, characterized in that: include: Obtain the series order set H and gear meshing frequency of the gears in the transmission system when the vehicle is traveling in a certain gear; Obtain the noise sound pressure signal function SP(t) of the vehicle during driving in this gear, and obtain the vehicle speed signal function T(tacho) synchronized with the noise sound pressure signal SP(t). Then process the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency to obtain the power density function L of the corresponding gear. h (w); According to the power density function L of the corresponding gear h (w) Calculate the order component energy A; According to the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B; Calculate the dark noise energy C, C=BA; Calculate the difference between the order component energy converted into decibels and the dark noise energy converted into decibels; The difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels is used to determine whether the noise is easily perceived by the human ear.

2. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: Obtaining the series order set H and gear meshing frequency of the vehicle transmission system includes: Obtain relevant parameters of gears in the vehicle transmission system, as well as vehicle speed and wheel rolling radius; Calculate the gear meshing frequency based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and wheel rolling radius; Calculate the gear meshing order based on the relevant parameters of the gears in the vehicle transmission system; Establish the series order set H of gears in the vehicle transmission system.

3. The vehicle transmission system gear noise online diagnosis method according to claim 2, characterized in that: The gear meshing frequency is calculated based on the relevant parameters of the gears in the vehicle transmission system, as well as the vehicle speed and wheel rolling radius using the following formula: in, f i - gear meshing frequency; r i - Speed ​​of the gear shaft; n i - number of gear teeth; V- vehicle speed; R- wheel rolling radius; i i - axle-to-wheel transmission ratio; The gear meshing order is calculated based on the relevant parameters of the gears in the vehicle transmission system using the following formula: in, h i - gear meshing order, n i - number of gear teeth, I i -The gear shaft's transmission ratio relative to the engine, and the gear series order set .

4. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: The order component energy A is calculated using the following formula: Among them, F N is the center noise frequency.

5. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: The critical bandwidth energy B is calculated by the following formula: Among them, F N is the center noise frequency, F C Critical bandwidth of the center frequency, Among them, F C Calculated by the following formula: 。 6. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: The difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels is calculated using the following formula: in, It is the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

7. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: Judging whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels includes: like If it is less than 0, it means that C is greater than A, indicating that the background noise is greater than the gear order noise and the gear noise is masked. At this time, it can be considered that the gear pair order noise will not be heard. is less than a predetermined threshold, which can be set as QdBA, i.e. If the value is less than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively small. Within the threshold Q range, it can be considered that the gear order noise cannot be distinguished from the background noise by the normal human hearing sensitivity. If it is greater than Q, it means that the ratio of the gear order noise to the background noise amplitude is relatively large. At this time, it can be considered that the gear order noise can be distinguished from the background noise with the normal hearing sensitivity of the human ear.

8. The vehicle transmission system gear noise online diagnosis method according to claim 1, characterized in that: The noise sound pressure signal function SP(t), vehicle speed signal function T(tacho), gear series order set H and gear meshing frequency are processed to obtain the power density function L of the corresponding gear h (w) include: Perform short-time Fourier transform on the collected noise sound pressure signal function SP(t) to obtain a three-dimensional matrix Q(w) of time, noise frequency and sound autopower spectrum amplitude; According to the engine speed corresponding to the moment, the three-dimensional matrix is ​​converted into a three-dimensional matrix L(w) of engine speed, noise frequency, and sound autopower spectrum amplitude; The engine speed signal function T(tacho) is used as the state vector to establish the state matrix of the Kalman filter to describe the law of engine speed change over time; According to the gear meshing frequency corresponding to the gear order in H, the corresponding power spectrum density amplitude can be searched in L(w), and the observation matrix is ​​established with the corresponding power spectrum density amplitude; The Kalman filter is used for harmonic tracking and the L(w) curve is filtered in real time to obtain the power density function L of the corresponding gear. h (w).

9. A vehicle transmission system gear noise online diagnosis system implementing the vehicle transmission system gear noise online diagnosis method according to any one of claims 1 to 8, characterized in that: include: An input module for obtaining a series order set H and a gear meshing frequency of a gear in a vehicle transmission system; an acquisition module, configured to acquire a noise sound pressure signal function SP(t) of a vehicle while the vehicle is traveling in a certain gear, and to acquire a vehicle speed signal function T(tacho) that is time-synchronized with the noise sound pressure signal SP(t); The calculation module is used to process the noise sound pressure signal function SP(t), the vehicle speed signal function T(tacho), the gear series order set H and the gear meshing frequency to obtain the power density function L of the corresponding gear. h (w), and is used to calculate the power density function L of the corresponding gear h (w) Calculate the order component energy A, which is used to calculate the power density function L of the corresponding gear h (w) Calculate the critical bandwidth energy B, which is used to calculate the dark noise energy C, C = BA; A conversion comparison module, used for calculating the difference between the order component energy converted into decibels and the dark noise energy converted into decibels; The judgment module is used to judge whether the noise is easily perceived by the human ear based on the difference between the gear order noise energy converted into decibels and the dark noise energy converted into decibels.

10. A computer-readable storage medium storing a computer program, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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