Motor housing noise detection method, device, computer equipment and storage medium

Abstract

The present application relates to a noise detection method, device, computer equipment and storage medium for a motor housing. The method comprises: obtaining a housing finite element model of the motor housing to be detected; applying a force to the motor mounting boss of the housing finite element model to determine a vibration response; and determining the equivalent radiation noise of different areas of the motor housing to be detected based on the vibration response. By obtaining the finite element model of the motor housing to be detected, the equivalent radiation noise corresponding to the motor housing can be determined in a timely manner at the beginning of the design, thereby improving the timeliness of the equivalent radiation noise detection. By applying a force to the motor mounting boss of the housing finite element model, the equivalent radiation noise of the motor housing can be determined, and the accuracy of the equivalent radiation noise of the motor housing can be further improved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a method, device, computer equipment and storage medium for detecting noise of a motor housing. Background Art

[0002] With the rapid development of new energy vehicles, its industry scale and market share are increasing year by year. For new energy vehicles, the motor noise evaluation of its hybrid transmission or motor housing assembly is a very important link. The evaluation of motor noise directly affects the user experience and the overall quality of new energy vehicles. The motor housing noise is an important component of motor noise.

[0003] In the current related technologies, when determining the motor housing noise, it is necessary to build a complete finite element model of the three-in-one assembly of the hybrid transmission, motor and power electronic controller. This process can only be carried out after the design and development of the three-in-one assembly is completed in the later stage. It is time-consuming and cannot timely and accurately determine the motor housing noise of the separate housing structure in the early design and development stage of the motor housing. Summary of the invention

[0004] Based on this, it is necessary to provide a noise detection method, device, computer equipment and storage medium for a motor housing in order to address the above technical problems.

[0005] In a first aspect, the present application provides a noise detection method for a motor housing, the method comprising: obtaining a housing finite element model of the motor housing to be detected; applying a force to the motor mounting boss of the housing finite element model to determine a vibration response; and determining the equivalent radiated noise of different areas of the motor housing to be detected based on the vibration response.

[0006] In one of the embodiments, applying a force to the motor mounting boss of the housing finite element model to determine the vibration response includes: constructing a circle based on the multiple motor mounting bosses of the housing finite element model; applying a force to the multiple motor mounting bosses of the housing finite element model in the radial and / or tangential direction of the circle to determine the vibration response.

[0007] In one embodiment, applying a force to the multiple motor mounting bosses of the shell finite element model in a radial direction and / or a tangential direction of the circle to determine the vibration response includes: applying a first force to the multiple motor mounting bosses of the shell finite element model in a radial direction of the circle to determine the first vibration response; applying a second force to the multiple motor mounting bosses of the shell finite element model in a tangential direction of the circle to determine the second vibration response.

[0008] In one of the embodiments, applying a first force to the multiple motor mounting bosses on the shell finite element model and determining a first vibration response includes: setting multiple first unit forces of different frequencies at a preset frequency step within a preset frequency range; applying first unit forces of different frequencies to the multiple motor mounting bosses on the shell finite element model in sequence, and determining a first vibration response corresponding to each frequency.

[0009] In one of the embodiments, applying a second force to the multiple motor mounting bosses on the shell finite element model and determining the second vibration response includes: setting multiple second unit forces of different frequencies at a preset frequency step within a preset frequency range; applying second unit forces of different frequencies to the multiple motor mounting bosses on the shell finite element model in sequence, and determining the second vibration response corresponding to each frequency.

[0010] In one of the embodiments, determining the equivalent radiated noise of different areas of the motor housing to be detected based on the vibration response includes: determining the target area of ​​the target area, the target first vibration response corresponding to the target area, and the target second vibration response corresponding to the target area based on the housing finite element model, the first vibration response, and the second vibration response; determining the first equivalent radiated noise of the first force corresponding to the target area based on the target area and the target first vibration response; determining the second equivalent radiated noise of the second force corresponding to the target area based on the target area and the target second vibration response.

[0011] In one of the embodiments, the method also includes: obtaining a preset noise threshold, multiple natural frequencies of the motor housing to be detected, and corresponding modal vibration shapes; comparing the equivalent radiated noise with the corresponding preset noise threshold to determine the abnormal frequency; searching for abnormal natural frequencies and corresponding abnormal modal vibration shapes among the multiple natural frequencies according to the abnormal frequency; determining the structural optimization strategy of the motor housing to be detected according to the abnormal natural frequencies and the corresponding abnormal modal vibration shapes.

[0012] In the second aspect, the present application also provides a noise detection device for a motor housing, the device comprising: an acquisition module for acquiring a housing finite element model of the motor housing to be detected; a vibration response determination module for applying a force to the motor mounting boss of the housing finite element model to determine the vibration response; an equivalent noise determination module for determining the equivalent radiated noise of different areas of the motor housing to be detected based on the vibration response.

[0013] In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, any one of the motor housing noise detection methods in the first aspect is implemented.

[0014] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the noise detection method for a motor housing according to any one of the first aspects is implemented.

[0015] The noise detection method, device, computer equipment and storage medium of the motor housing described above obtain the housing finite element model of the motor housing to be detected, apply a force to the motor mounting boss of the housing finite element model, determine the vibration response, and finally determine the equivalent radiation noise of different areas of the motor housing to be detected based on the vibration response. By obtaining the finite element model of the motor housing to be detected, the equivalent radiation noise corresponding to the motor housing can be determined in time at the early stage of design, improving the timeliness of the equivalent radiation noise detection, and by applying a force to the motor mounting boss of the housing finite element model, the equivalent radiation noise of the motor housing can be determined, which can further improve the accuracy of the equivalent radiation noise of the motor housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic flow chart of a method for detecting noise of a motor housing in one embodiment;

[0017] Figure 2 A schematic diagram of a flow chart of a vibration response calculation method in one embodiment;

[0018] Figure 3 is a schematic diagram of applying a force in a radial direction in one embodiment;

[0019] Figure 4 is a schematic diagram of applying a force in a tangential direction in one embodiment;

[0020] Figure 5 is a schematic diagram of a flow chart of a method for calculating equivalent radiation noise in one embodiment;

[0021] Figure 6 A schematic diagram of a flow chart of a method for optimizing the structure of a motor housing in one embodiment;

[0022] Figure 7 It is a schematic diagram of a flow chart of a noise detection method for a motor housing in a specific embodiment;

[0023] Figure 8 is a structural block diagram of a noise detection device for a motor housing in one embodiment;

[0024] Fig. 9 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] NVH, or Noise, Vibration and Harshness, is a comprehensive issue to measure the quality of automobile manufacturing. It gives users the most direct and superficial experience. Motor whine is a common NVH problem in new energy vehicles. Motor whine is mainly caused by vibration and noise caused by electromagnetic force, especially noise in the high frequency band, which has a negative impact on user experience. The motor housing noise is an important part of motor whine. Conventional motor housing noise detection is to output electromagnetic force at the stator or rotor, apply electromagnetic force to the stator and rotor respectively, and then evaluate the response at the suspension installation point or calculate the whole machine sound field to determine the area where the motor housing vibration or noise does not meet the standard, and then optimize the structure of the motor housing. The above noise detection and optimization cycle for the motor housing is long. It is necessary to build a complete three-in-one assembly model before the noise of the motor housing can be determined. It cannot meet the timely detection of motor housing noise in the early design and development process, that is, it is impossible to determine the geometric data of the motor housing in the early stage. Understandably, conventional analysis methods require the construction of a complete finite element model of the hybrid transmission and the motor, which means that the motor housing noise can only be evaluated in the later stages of the design. In addition, the model is large, time-consuming, and labor-intensive. When evaluating the motor housing noise, the opportunity to determine the geometric data of the motor housing has been missed. If it is assessed that the motor housing noise does not meet the standard and the geometric data of the motor housing needs to be modified, the motor housing must be redesigned and molded, wasting a lot of manpower and material costs. In addition, when building a complete three-in-one assembly model, the accuracy of the motor stator and rotor finite element models depends on the calibration of the measured model. There is no physical sample of the motor in the early stages of the design, and the modal calibration requirements cannot be met, which means that the accuracy of the motor housing noise is low.

[0027] The embodiment of the present application provides a noise detection method for a motor housing. In the early stage of design, it is only necessary to build a finite element model corresponding to the motor housing, and apply a force at the motor mounting boss of the finite element model to output the equivalent radiation noise of the motor housing. The equivalent radiation noise of the motor housing can be quickly evaluated in the early stage of design, and the geometric data of the motor housing can be determined. It avoids the need to redesign and open the mold of the motor housing in the later stage of design, saving manpower and material costs. And by applying a force at the motor mounting boss of the finite element model, the equivalent radiation noise of the motor housing is output, which improves the accuracy of the equivalent radiation noise of the motor housing.

[0028] In one embodiment, Figure 1 As shown, a method for detecting noise of a motor housing is provided, comprising the following steps:

[0029] Step 101: Obtain a housing finite element model of a motor housing to be inspected.

[0030] In the early stage of motor design, after the motor housing design is completed, a housing finite element model is generated according to the geometric data of the motor housing. Among them, the motor housing to be tested is the motor housing that has been designed, and the equivalent radiation noise of the motor housing needs to be tested. The motor housing, that is, the motor assembly housing includes: a front housing, an intermediate housing and a rear housing. The front housing corresponds to the driving end of the motor and is used to install the front end bearing of the motor; the intermediate housing is used to accommodate the motor stator; the rear housing corresponds to the non-driving end of the motor and is used to install the rear end bearing of the motor. After the motor housing design is completed, the geometric models of the motor housing, PCM controller and bolts are first obtained. The parameters of the geometric model include parameters such as shape, size, strength and performance. After obtaining the geometric model of the motor housing, a housing finite element model of the motor housing to be tested is constructed according to the geometric model, and the housing finite element model is obtained when detecting the equivalent radiation noise.

[0031] Step 102 : applying a force to the motor mounting boss of the housing finite element model to determine a vibration response.

[0032] The shell finite element model corresponds to a motor mounting boss, which is used to fix the motor. Specifically, the motor mounting boss is a stator mounting boss, which is used to install the stator. After obtaining the shell finite element model, a force is applied to the motor mounting boss of the shell finite element model, and then the modal superposition method is used to perform steady-state dynamics solution to determine the vibration response. Among them, the force can be multiple forces, and the magnitude of the force applied between the multiple forces can be different, the frequency of the force applied can be different, and the direction of the force applied can be different. For each force, the vibration response of the corresponding force can be calculated. For the magnitude of the force, it can be 5N or 10N. This embodiment does not make a specific limitation, and it can preferably be 1N. The vibration response includes at least one of vibration displacement, vibration velocity and vibration acceleration.

[0033] Step 103: determining the equivalent radiated noise of different areas of the motor housing to be detected according to the vibration response.

[0034] After the vibration response corresponding to the force is calculated, the equivalent radiation noise of different areas when different forces act on the motor housing to be tested can be determined according to the vibration response of different forces. For example, the equivalent radiation noise of the front housing when different forces act on the motor housing to be tested, the equivalent radiation noise of the middle housing when different forces act on the motor housing to be tested, the equivalent radiation noise of the rear housing when different forces act on the motor housing to be tested, and the equivalent radiation noise of the motor housing, that is, the motor assembly housing, when different forces act on the motor housing to be tested.

[0035] This embodiment obtains the shell finite element model of the motor shell to be detected, applies a force to the motor mounting boss of the shell finite element model, determines the vibration response, and finally determines the equivalent radiation noise of different areas of the motor shell to be detected based on the vibration response. By obtaining the finite element model of the motor shell to be detected, the equivalent radiation noise corresponding to the motor shell can be determined in time at the beginning of the design, improving the timeliness of the equivalent radiation noise detection, and by applying a force to the motor mounting boss of the shell finite element model, the equivalent radiation noise of the motor shell can be determined, which can further improve the accuracy of the equivalent radiation noise of the motor shell.

[0036] In one of the embodiments, after the shell finite element model of the motor shell to be detected is constructed, the shell finite element model can also be modally solved to determine the natural frequency and modal vibration shape of the motor shell to be detected. Specifically, the shell finite element model can be subjected to a finite element analysis method and a finite element solution software to determine the natural frequency and modal vibration shape of the motor shell to be detected. Among them, the finite element analysis method can be the Lesos method; the range of the finite element analysis can be 0-10000HZ. There are multiple natural frequencies obtained by the solution, and each natural frequency has a corresponding modal vibration shape. The number of natural frequencies is related to the structural strength of the motor shell to be detected. The greater the structural strength, the fewer the number of natural frequencies; the smaller the structural strength, the more the number of natural frequencies. After determining the multiple natural frequencies and corresponding modal vibration shapes of the motor shell to be detected by the finite element analysis method, the accuracy of the shell finite element model needs to be detected. Actual tests are performed on the actual motor housing to be tested to obtain multiple natural frequencies and corresponding modal vibration shapes. The multiple natural frequencies determined by the finite element analysis method are compared with the multiple natural frequencies obtained by the actual test. If the error of the natural frequency is within 5%, the inspection passes. If the inspection fails, the housing finite element model is reconstructed.

[0037] This embodiment determines the natural frequency and modal vibration shape of the motor housing to be tested by performing modal solution on the housing finite element model. When subsequently calculating the vibration response, adding the information of the natural frequency and modal vibration shape can improve the accuracy of calculating the vibration response.

[0038] In one embodiment, if Figure 2 As shown, a vibration response calculation method is provided, comprising the following steps:

[0039] Step 201 , constructing a circle based on multiple motor mounting bosses of the housing finite element model.

[0040] The housing finite element model corresponds to a plurality of motor mounting bosses. The specific number of motor mounting bosses is determined according to the structure of the actual motor housing, and is not specifically limited in this embodiment. The following is an example in which the housing finite element model corresponds to four motor mounting bosses. Figure 3 as well as Figure 4 As shown, boss A, boss B, boss C and boss D are four motor mounting bosses. First, the center points of the plurality of motor mounting bosses are determined, a circle is constructed through the center points of the plurality of motor mounting bosses, and the center of the circle is determined.

[0041] Step 202 : applying forces to multiple motor mounting bosses of the housing finite element model in a circular radial direction and / or tangential direction to determine vibration responses.

[0042] When applying forces to multiple motor mounting bosses of the housing finite element model, Figure 3 As shown, at each motor mounting boss, a force F1 is applied in a circular radial direction; it can also be as Figure 4 As shown, at each motor mounting boss, a force F2 is applied in a circular tangential direction. When calculating the vibration response, only the force in the radial direction may be applied to determine the vibration response corresponding to the force in the radial direction; only the force in the tangential direction may be applied to determine the vibration response corresponding to the force in the tangential direction; or the force in the radial direction and the force in the tangential direction may be applied separately to determine the vibration response corresponding to the force in the radial direction and the vibration response corresponding to the force in the tangential direction.

[0043] In a circular radial direction, a first force is applied to multiple motor mounting bosses of the shell finite element model to determine a first vibration response. The first force is a force in the radial direction. Among them, the shell finite element model can be a meshed model. Before applying the first force, multiple first unit forces of different frequencies are set in a preset frequency range with a preset frequency step. The first unit forces of multiple different frequencies are also the first force. Among them, the preset frequency range can be 0-7000HZ, or 0-5000HZ, which is not specifically limited in this embodiment. Preferably, the preset frequency range can be 0-6000HZ. The preset frequency step can be 5HZ or 10HZ, which is not specifically limited in this embodiment. Preferably, the preset frequency step can be 8HZ. The first unit force can be a force of 1N in the radial direction. For example, in the range of 0-6000HZ, set the frequency to 10HZ and the first unit force to 1N; set the frequency to 18HZ and the first unit force to 1N; set the frequency to 26HZ and the first unit force to 1N; successively use 8HZ as the preset frequency step until the frequency is set to 5994HZ and the first unit force is 1N. Among them, there are 749 first unit forces of different frequencies. After setting the first unit forces of multiple different frequencies, apply the first unit forces of different frequencies to the multiple motor mounting bosses of the shell finite element model in turn, and determine the first vibration response corresponding to each frequency. In the radial direction of the circle, apply the first unit forces of multiple different frequencies to the multiple motor mounting bosses in turn. For example, a first unit force of 10 Hz and 1 N is applied simultaneously in the radial direction of a circle to four motor mounting bosses, and the first vibration response corresponding to the first unit force of 10 Hz is determined; a first unit force of 18 Hz and 1 N is applied simultaneously in the radial direction of a circle to four motor mounting bosses, and the first vibration response corresponding to the first unit force of 18 Hz is determined; and so on, a first unit force of 5994 Hz and 1 N is applied simultaneously in the radial direction of a circle to four motor mounting bosses, and the first vibration response corresponding to the first unit force of 5994 Hz is determined. A total of 749 first vibration responses corresponding to the first unit force of frequencies are obtained. The vibration response includes: the vibration displacement, vibration velocity, and vibration acceleration corresponding to each node in the meshed shell finite element model.

[0044] In the tangential direction of the circle, a second force is applied to multiple motor mounting bosses of the shell finite element model to determine a second vibration response. The second force is a force in the tangential direction. Among them, the shell finite element model can be a meshed model. Before applying the second force, multiple second unit forces of different frequencies are set in a preset frequency range with a preset frequency step, and multiple second unit forces of different frequencies are also the second force. Among them, the preset frequency range can be 0-7000HZ, or 0-5000HZ, which is not specifically limited in this embodiment. Preferably, the preset frequency range can be 0-6000HZ. The preset frequency step can be 5HZ or 10HZ, which is not specifically limited in this embodiment. Preferably, the preset frequency step can be 8HZ. The second unit force can be a force of 1N in the tangential direction. For example, in the range of 0-6000HZ, set the frequency to 10HZ and the second unit force to 1N; set the frequency to 18HZ and the second unit force to 1N; set the frequency to 26HZ and the second unit force to 1N; successively use 8HZ as the preset frequency step until the frequency is set to 5994HZ and the second unit force is 1N. Among them, there are 749 second unit forces of different frequencies. After setting the second unit forces of multiple different frequencies, apply the second unit forces of different frequencies to the multiple motor mounting bosses of the shell finite element model in turn, and determine the second vibration response corresponding to each frequency. In the tangential direction of the circle, apply the second unit forces of multiple different frequencies to the multiple motor mounting bosses in turn. For example, a second unit force of 10 Hz and 1 N is applied simultaneously to four motor mounting bosses in the tangential direction of the circle, and the second vibration response corresponding to the second unit force of 10 Hz is determined; a second unit force of 18 Hz and 1 N is applied simultaneously to four motor mounting bosses in the tangential direction of the circle, and the second vibration response corresponding to the second unit force of 18 Hz is determined; and so on, a second unit force of 5994 Hz and 1 N is applied simultaneously to four motor mounting bosses in the tangential direction of the circle, and the second vibration response corresponding to the second unit force of 5994 Hz is determined. A total of 749 second vibration responses corresponding to the second unit force of frequencies are obtained. The vibration response includes: the vibration displacement, vibration velocity, and vibration acceleration corresponding to each node in the meshed shell finite element model.

[0045] For example, only the first force in the radial direction may be applied to determine the first vibration response; only the second force in the tangential direction may be applied to determine the second vibration response; or the first force in the radial direction and the second force in the tangential direction may be applied separately to determine the first vibration response and the second vibration response respectively.

[0046] This embodiment applies multiple forces of different directions and frequencies to the motor mounting boss of the housing finite element model to determine the vibration response corresponding to each force. By applying multiple forces of different directions and frequencies, the vibration of the motor housing during actual use can be more comprehensively considered, so that the subsequent determination of the equivalent radiated noise is more accurate.

[0047] In one embodiment, if Figure 5 As shown, a method for calculating equivalent radiation noise is provided, comprising the following steps:

[0048] Step 501 : determining a target area of ​​a target area, a target first vibration response corresponding to the target area, and a target second vibration response corresponding to the target area according to a shell finite element model, a first vibration response, and a second vibration response.

[0049] The first vibration response includes: a first vibration response corresponding to a first unit force at each frequency. The second vibration response includes: a second vibration response corresponding to a second unit force at each frequency. First, the target area is determined. The target area may be an area where equivalent radiated noise needs to be detected, such as a front housing area, a middle housing area, a rear housing area, and a motor assembly housing area. The target area is not specifically limited in this embodiment, and it is only required that the target area is an area within the housing finite element model. After the target area is determined, the target area area of ​​the target area is determined according to the housing finite element model. According to the housing finite element model and the first vibration response, the target first vibration response corresponding to the target area is determined, wherein the target first vibration response includes: a first vibration response corresponding to a first unit force at each frequency in the target area. According to the housing finite element model and the second vibration response, the target second vibration response corresponding to the target area is determined, wherein the target second vibration response includes: a second vibration response corresponding to a second unit force at each frequency in the target area.

[0050] Step 502: determining a first equivalent radiated noise of a first force corresponding to the target area according to the area of ​​the target area and the first vibration response of the target.

[0051] The first force includes first unit forces of different frequencies. For the target area, the first equivalent radiation noise corresponding to the first unit force of each frequency is first calculated. Then, the first equivalent radiation noise of the first force is generated according to the first equivalent radiation noise corresponding to the first unit force of all frequencies. The specific calculation method for the first equivalent radiation noise corresponding to the first unit force of each frequency is as follows:

[0052]

[0053] Among them, ERP is the equivalent radiation noise, ERPLF is the radiation loss coefficient, ERPC is the speed of sound, ERPRHO is the liquid density, Ai is the area of ​​the i-th node in the target area, vi is the vibration velocity of the i-th node corresponding to the corresponding frequency in the target area, and ngrid is the total number of nodes in the target area. The radiation loss coefficient, speed of sound, and liquid density are all set to 1.

[0054] After calculating the first equivalent radiation noise corresponding to the first unit force of each frequency, a curve is fitted according to all frequencies and the corresponding first equivalent radiation noises, and the fitted curve is used as the first equivalent radiation noise corresponding to the first force of the target area.

[0055] Step 503: Determine a second equivalent radiation noise of a second force corresponding to the target area according to the area of ​​the target area and the second vibration response of the target.

[0056] The second force includes second unit forces of different frequencies. For the target area, first calculate the second equivalent radiation noise corresponding to the second unit force of each frequency. Then, based on the second equivalent radiation noise corresponding to the second unit force of all frequencies, generate the second equivalent radiation noise of the second force. The specific calculation method for the second equivalent radiation noise corresponding to the second unit force of each frequency is as follows:

[0057]

[0058] Among them, ERP is the equivalent radiation noise, ERPLF is the radiation loss coefficient, ERPC is the speed of sound, ERPRHO is the liquid density, Ai is the area of ​​the i-th node in the target area, vi is the vibration velocity of the i-th node corresponding to the corresponding frequency in the target area, and ngrid is the total number of nodes in the target area. The radiation loss coefficient, speed of sound, and liquid density are all set to 1.

[0059] After calculating the second equivalent radiation noise corresponding to the second unit force of each frequency, a curve is fitted according to all frequencies and the corresponding second equivalent radiation noises, and the fitted curve is used as the second equivalent radiation noise corresponding to the second force of the target area.

[0060] Finally, the first equivalent radiation noise of the first force corresponding to the target area and the second equivalent radiation noise of the second force corresponding to the target area are used as the equivalent radiation noise of the target area.

[0061] In this embodiment, the equivalent radiation noise corresponding to multiple forces is calculated, which can more comprehensively consider the vibration of the motor housing during actual use, thereby more accurately reflecting the equivalent radiation noise of the target area.

[0062] In one embodiment, if Figure 6 As shown, a method for optimizing the structure of a motor housing is provided, comprising the following steps:

[0063] Step 601: Obtain a preset noise threshold, multiple natural frequencies of a motor housing to be detected, and corresponding mode vibration shapes.

[0064] The preset noise thresholds include multiple ones, for example, including: a preset noise threshold corresponding to the first force in the front housing area, a preset noise threshold corresponding to the second force in the front housing area, a preset noise threshold corresponding to the first force in the middle housing area, a preset noise threshold corresponding to the second force in the middle housing area, a preset noise threshold corresponding to the first force in the rear housing area, a preset noise threshold corresponding to the second force in the rear housing area, a preset noise threshold corresponding to the first force in the motor assembly housing area, and a preset noise threshold corresponding to the second force in the motor assembly housing area. The preset noise thresholds may include: a noise threshold range corresponding to each frequency. The noise threshold range is determined based on historically similar motor products. First, the maximum value and the minimum value of the equivalent radiation noise of each motor product at each frequency point in each target area are determined respectively, and then the noise threshold range for each force in each target area is determined based on the maximum value and the minimum value of the equivalent radiation noise.

[0065] Step 602: Compare the equivalent radiation noise with the corresponding preset noise threshold to determine the abnormal frequency.

[0066] After calculating the equivalent radiation noise of the target area, it is necessary to first determine the corresponding preset noise threshold. For example, if the first equivalent radiation noise of the first force corresponding to the front shell area is calculated, the corresponding preset noise threshold is the preset noise threshold of the first force corresponding to the front shell area; if the second equivalent radiation noise of the second force corresponding to the middle shell area is calculated, the corresponding preset noise threshold is the preset noise threshold of the second force corresponding to the middle shell area. In the equivalent radiation noise of the target area, the equivalent radiation noise of each frequency is compared with the noise threshold range of the corresponding frequency. If the equivalent radiation noise of the corresponding frequency is not within the noise threshold range of the corresponding frequency, the corresponding frequency is determined to be an abnormal frequency. If the equivalent radiation noise of each frequency is within the noise threshold range of the corresponding frequency, the motor housing structure to be detected is good and is not easy to generate noise.

[0067] Step 603: searching for an abnormal natural frequency and a corresponding abnormal mode shape among multiple natural frequencies according to the abnormal frequency.

[0068] After the abnormal frequency is determined, at least one natural frequency closest to the abnormal frequency is searched among all natural frequencies. For example, after the abnormal frequency is determined, the absolute value of the frequency difference between the abnormal frequency and each natural frequency is calculated. When only one natural frequency needs to be searched, the natural frequency with the smallest absolute value of the frequency difference is searched as the abnormal natural frequency, and the corresponding modal vibration shape is used as the abnormal modal vibration shape.

[0069] Step 604: Determine a structural optimization strategy for the motor housing to be inspected according to the abnormal natural frequency and the corresponding abnormal mode shape.

[0070] Finally, the structural optimization strategy of the motor housing to be inspected is determined based on the abnormal natural frequency and the corresponding abnormal modal vibration shape. For example, the structural stiffness of the weak area of ​​the structural strain energy density (Abaqus or Optistruct) is optimized based on the abnormal natural frequency and the corresponding abnormal modal vibration shape, such as increasing the wall thickness or strengthening the ribs; the topology optimization solution can also be used to optimize the stiffness of the structure.

[0071] This embodiment can timely optimize the geometric parameters of the motor housing in the early stage of motor design, avoiding the need to redesign and open a mold for the motor housing in the later stage of design, thus saving manpower and material costs.

[0072] In one specific embodiment, Figure 7 As shown, a noise detection method for a motor housing is provided, which specifically discloses first collecting the solid geometric models and material grades of the motor housing, i.e., the motor assembly housing, the PCM controller, bolts, etc. According to the above-mentioned geometric model and material grade, a finite element model of the motor housing is established, and a modal solution is performed. Specifically, a finite element model of the motor housing and the controller is built, and the simulation model is modally solved to obtain the natural frequency and modal vibration shape of the motor housing. The modal solution method is the Lesos method, and the modal solution range is 0-10000Hz. After the natural frequency and modal vibration shape of the motor housing are obtained by modal solution, they are compared with the natural frequency and modal vibration shape obtained by testing the real structure to detect the accuracy of the finite element model. If the difference is within 5%, the finite element model is accurate.

[0073] After obtaining the finite element model of the motor housing, load the radial unit load to the motor mounting boss. Construct a circle with the center of the four motor mounting bosses of the motor housing finite element model, and determine the center of the circle O. At the motor mounting boss, load the unit load in the radial direction from the center of the circle to the motor mounting boss. Figure 3As shown, with OA as the radial load loading direction, a unit load is loaded at boss A; with OB as the radial load loading direction, a unit load is loaded at boss B; with OC as the radial load loading direction, a unit load is loaded at boss C; with OD as the radial load loading direction, a unit load is loaded at boss D. The unit load is F1, and the frequency range of the unit load is 0-6000HZ. After loading is completed, the steady-state dynamics solution is performed according to the modal superposition method to obtain a meshed finite element model of the motor housing, and for each frequency, the displacement, velocity and acceleration corresponding to each grid point. Then, based on the radial unit load, the equivalent radiation noise of the motor housing is calculated, specifically including: the equivalent radiation noise of the front housing of the motor, the equivalent radiation noise of the middle housing of the motor, the equivalent radiation noise of the rear housing of the motor, and the equivalent radiation noise of the motor assembly housing.

[0074] After obtaining the finite element model of the motor housing, load the tangential unit load to the motor mounting boss. Construct a circle with the centers of the four motor mounting bosses of the motor housing finite element model, and determine the center O of the circle. Load the unit load in the tangential direction at the motor mounting boss. Figure 4 As shown, a unit load is loaded at boss A in the tangential direction; a unit load is loaded at boss B in the tangential direction; a unit load is loaded at boss C in the tangential direction; and a unit load is loaded at boss D in the tangential direction. The unit load is F2, and the frequency range of the unit load is 0-6000HZ. After loading is completed, the steady-state dynamics solution is performed according to the modal superposition method to obtain a gridded finite element model of the motor housing, and for each frequency, the displacement, velocity and acceleration corresponding to each grid point. Then, based on the tangential unit load, the equivalent radiation noise of the motor housing is calculated, specifically including: the equivalent radiation noise of the front housing of the motor, the equivalent radiation noise of the middle housing of the motor, the equivalent radiation noise of the rear housing of the motor, and the equivalent radiation noise of the motor assembly housing.

[0075] The equivalent radiation noise of the motor housing based on the radial unit load is put into the noise database for comparison. The database stores the noise threshold range for each frequency point based on the radial unit load. If the equivalent radiation noise of the motor housing is within the noise threshold range, it is considered that the NVH risk of the motor housing is low.

[0076] The equivalent radiation noise of the motor housing based on the tangential unit load is put into the noise database for comparison. The database stores the noise threshold range for each frequency point based on the tangential unit load. If the equivalent radiation noise of the motor housing is within the noise threshold range, it is considered that the NVH risk of the motor housing is low.

[0077] If the equivalent radiation noise of the motor housing in any of the above directions is higher than the corresponding noise threshold range, the abnormal frequency higher than the noise threshold range is determined, and the corresponding natural frequency is determined based on the abnormal frequency. According to the natural frequency and the working vibration mode, the structural stiffness of the weak area of ​​the structural strain energy density (Abaqus or Optistruct) is optimized, such as increasing the wall thickness or reinforcing ribs; the topology optimization scheme can also be used to optimize the stiffness of the structure to find the optimal structural feature distribution of NVH. Repeat the above steps until the equivalent radiation noise of the motor housing corresponding to the optimized radial unit load and tangential unit load is within the corresponding noise threshold range.

[0078] If the equivalent radiation noise of the motor housing in the above two directions is within the corresponding noise threshold range, it is determined that the radiation noise risk of the motor housing assembly is low, and the housing data is frozen, that is, the geometric data of the motor housing is determined.

[0079] This embodiment can be quickly applied in the early stage of product development to quickly evaluate the NVH structural characteristics of the housing assembly motor and make targeted improvements to avoid the motor howling problem caused by housing resonance in the later stage, which affects the project delivery cycle and project development costs.

[0080] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0081] Based on the same inventive concept, the embodiment of the present application also provides a noise detection device for a motor housing for implementing the noise detection method for a motor housing involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of one or more noise detection devices for motor housings provided below can refer to the limitations of the noise detection method for motor housings above, and will not be repeated here.

[0082] In one embodiment, Figure 8 As shown, a noise detection device for a motor housing is provided, comprising: an acquisition module 100, a vibration response determination module 200 and an equivalent noise determination module 300, wherein:

[0083] The acquisition module 100 is used to acquire a housing finite element model of the motor housing to be detected.

[0084] The vibration response determination module 200 is used to apply a force to the motor mounting boss of the housing finite element model to determine the vibration response.

[0085] The equivalent noise determination module 300 is used to determine the equivalent radiated noise of different areas of the motor housing to be detected according to the vibration response.

[0086] The vibration response determination module 200 is also used to construct a circle based on the multiple motor mounting bosses of the shell finite element model; apply force to the multiple motor mounting bosses in the shell finite element model in the radial and / or tangential direction of the circle to determine the vibration response.

[0087] The vibration response determination module 200 is also used to apply a first force to the multiple motor mounting bosses in the shell finite element model in the radial direction of the circle to determine the first vibration response; and to apply a second force to the multiple motor mounting bosses in the shell finite element model in the tangential direction of the circle to determine the second vibration response.

[0088] The vibration response determination module 200 is also used to set a plurality of first unit forces of different frequencies within a preset frequency range at a preset frequency step; first unit forces of different frequencies are applied sequentially to the plurality of motor mounting bosses of the shell finite element model to determine a first vibration response corresponding to each frequency.

[0089] The vibration response determination module 200 is also used to set multiple second unit forces of different frequencies within a preset frequency range with a preset frequency step; second unit forces of different frequencies are applied to multiple motor mounting bosses of the shell finite element model in sequence to determine the second vibration response corresponding to each frequency.

[0090] The equivalent noise determination module 300 is also used to determine the target area of ​​the target area, the target first vibration response corresponding to the target area, and the target second vibration response corresponding to the target area according to the shell finite element model, the first vibration response, and the second vibration response; determine the first equivalent radiation noise of the first force corresponding to the target area according to the target area and the target first vibration response; determine the second equivalent radiation noise of the second force corresponding to the target area according to the target area and the target second vibration response.

[0091] The equivalent noise determination module 300 is also used to obtain a preset noise threshold, multiple natural frequencies of the motor housing to be detected, and corresponding modal vibration shapes; compare the equivalent radiated noise with the corresponding preset noise threshold to determine the abnormal frequency; search for abnormal natural frequencies and corresponding abnormal modal vibration shapes among the multiple natural frequencies according to the abnormal frequency; determine the structural optimization strategy of the motor housing to be detected according to the abnormal natural frequencies and the corresponding abnormal modal vibration shapes.

[0092] Each module in the noise detection device for the motor housing can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0093] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Fig. 9 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a noise detection method for a motor housing is implemented.

[0094] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0095] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, any one of the motor housing noise detection methods in the above embodiments is implemented.

[0096] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, any one of the noise detection methods for a motor housing in the above embodiments is implemented.

[0097] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, any one of the noise detection methods for a motor housing in the above embodiments is implemented.

[0098] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0099] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for detecting noise of a motor housing, characterized in that: The method comprises: Obtaining a shell finite element model of the motor shell to be tested; Applying a force to the motor mounting boss of the housing finite element model to determine a vibration response; the applied force is a plurality of forces, and at least one of the magnitudes, frequencies and directions of the plurality of forces is different; The equivalent radiated noise of different areas of the motor housing to be detected is determined according to the vibration response.

2. The method according to claim 1, characterized in that Applying a force to the motor mounting boss of the housing finite element model to determine the vibration response includes: Constructing a circle based on the plurality of motor mounting bosses of the housing finite element model; A force is applied to the plurality of motor mounting bosses of the housing finite element model in a radial direction and / or a tangential direction of the circle to determine a vibration response.

3. The method according to claim 2, characterized in that Applying a force to the plurality of motor mounting bosses of the housing finite element model in a radial direction and / or a tangential direction of the circle to determine the vibration response comprises: Applying a first force to a plurality of the motor mounting bosses on the housing finite element model in a radial direction of the circle to determine a first vibration response; A second force is applied to the plurality of motor mounting bosses of the housing finite element model in a tangential direction of the circle to determine a second vibration response.

4. The method according to claim 3, characterized in that Applying a first force to the plurality of motor mounting bosses on the housing finite element model to determine a first vibration response comprises: Setting a plurality of first unit forces of different frequencies with a preset frequency step within a preset frequency range; First unit forces of different frequencies are sequentially applied to the plurality of motor mounting bosses of the housing finite element model to determine a first vibration response corresponding to each frequency.

5. The method according to claim 3, characterized in that: Applying a second force to the plurality of motor mounting bosses on the housing finite element model to determine a second vibration response comprises: Setting a plurality of second unit forces of different frequencies in a preset frequency range with a preset frequency step size; Second unit forces of different frequencies are sequentially applied to the plurality of motor mounting bosses of the housing finite element model to determine a second vibration response corresponding to each frequency.

6. The method according to claim 3, characterized in that Determining the equivalent radiated noise of different areas of the motor housing to be detected according to the vibration response includes: Determining a target area of ​​a target area, a target first vibration response corresponding to the target area, and a target second vibration response corresponding to the target area according to the shell finite element model, the first vibration response, and the second vibration response; Determining a first equivalent radiated noise of a first force corresponding to the target area according to the area of ​​the target area and the first vibration response of the target; A second equivalent radiation noise of a second force corresponding to the target area is determined according to the area of ​​the target area and the second vibration response of the target.

7. The method according to claim 1, characterized in that The method further comprises: Acquire a preset noise threshold, a plurality of natural frequencies of the motor housing to be detected, and corresponding modal vibration shapes; Comparing the equivalent radiation noise with the corresponding preset noise threshold to determine the abnormal frequency; According to the abnormal frequency, searching for an abnormal natural frequency and a corresponding abnormal mode vibration shape among the multiple natural frequencies; A structural optimization strategy for the motor housing to be inspected is determined based on the abnormal natural frequency and the corresponding abnormal mode vibration shape.

8. A noise detection device for a motor housing, characterized in that: The device comprises: An acquisition module, used for acquiring a shell finite element model of a motor shell to be detected; A vibration response determination module, used to apply a force to the motor mounting boss of the housing finite element model to determine the vibration response; the applied force is a plurality of forces, and at least one of the magnitudes, frequencies and directions corresponding to the plurality of forces is different; The equivalent noise determination module is used to determine the equivalent radiated noise of different areas of the motor housing to be detected according to the vibration response.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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