Vibration absorption and isolation design method and device for electric drive system

Abstract

The invention relates to the field of new energy automobile electric driving systems, in particular to a vibration absorption and isolation design method and device for an electric driving system, and the method comprises the steps: constructing a plurality of measurement point vibration order curves and a measurement point noise order curve through the analysis of a vibration acceleration signal and a radiation sound signal of a motor controller; according to a radiation sound signal and a measurement point noise order curve, a vibration measurement point for transmitting vibration energy is determined according to the measurement point vibration order curve, a vibration absorption and isolation design bolt kit which is simple in structure and convenient to operate is designed according to the radiation sound signal and the measurement point noise order curve, and the vibration absorption and isolation design bolt kit is installed on the vibration measurement point for transmitting the vibration energy. The suppression of the radiation noise of the motor controller can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric drive systems of new energy vehicles, and particularly relates to a vibration absorption and isolation design method and device for an electric drive system. BACKGROUND

[0002] In the working process of the motor controller of the electric drive system of a new energy vehicle, the power semiconductor devices inside the motor controller will continuously perform high-frequency switching actions and generate complex electromagnetic interference. These electromagnetic interferences will be transmitted outward through wires, metal shells and other channels, causing structural vibration, thus generating relatively large acoustic radiation and relatively large radiation noise.

[0003] Radiation noise is a source of electromagnetic interference, which can cause vibration of structural components of a new energy vehicle, resulting in additional alternating stress borne by the structural components, thus accelerating the wear of the components and easily causing structural fatigue. In addition, the noise generated by acoustic radiation enters the vehicle, which can make the driver of the vehicle feel annoyed and uneasy, thus affecting the judgment and decision-making of the driver; the component shaking caused by radiation noise can also interfere with the driver's vision, affecting driving safety.

[0004] At present, the radiation noise of the electric drive system is mainly suppressed by electromagnetic shielding technology, filtering technology and other methods, but these methods all have deficiencies, for example:

[0005] 1) Electromagnetic shielding technology

[0006] ① Specific method: a shielding cover (such as a metal shielding cover, a shielding net, etc.) with electromagnetic shielding properties is used to wrap the electromagnetic interference source in the electric drive system, forming a closed electromagnetic shielding space to prevent electromagnetic waves from radiating outward;

[0007] ② Deficiency: the shielding effect of the shielding cover will be affected by various factors such as the performance of the shielding material, the integrity of the shielding structure, and whether the grounding is good or not, and needs to be designed according to the specific circumstances of the electromagnetic interference source in the electric drive system, while the price of the shielding cover material is generally high, and the design, manufacturing and installation process of the shielding cover often requires high technology and cost investment.

[0008] 2) Filtering technology

[0009] ① Specific method: a filter composed of inductors, capacitors and other elements is installed on the power input end and signal transmission line of the electric drive system, which can attenuate electromagnetic interference of specific frequency and reduce the intensity of radiation noise;

[0010] The disadvantages are that the suppression effect of the filter on electromagnetic interference is affected by the precision and stability of the element parameters, but the electromagnetic interference spectrum of different electric drive systems in different working states is different, which requires the parameters of the filter to be adjusted according to the actual situation. However, the adjustment of the filter parameters is often complex and requires professional equipment and technical personnel to spend a lot of time debugging. In addition, the size and weight of the filter cannot be ignored, especially for some compact electric drive systems, the installation position of the filter may be limited. Moreover, the performance of the filter may gradually decrease due to the aging of the elements and environmental factors during long-term use, and regular maintenance and replacement are required.

[0011] Therefore, the above-mentioned traditional methods for suppressing the radiation noise of the electric drive system have a very complex implementation process, a long development cycle, and greatly increase the cost of the electric drive system.

[0012] Therefore, how to provide a simple, fast and low-cost method for suppressing the radiation noise of the electric drive system has been a problem to be solved by those skilled in the art. SUMMARY

[0013] The purpose of the present application is to overcome the corresponding deficiencies of the prior art, provide a vibration absorption and isolation design method and device for an electric drive system, analyze the vibration acceleration signals and radiation sound signals of the motor controller, construct a plurality of vibration order curves of the measuring points and a noise order curve of the measuring point, determine the vibration measuring points that transmit vibration energy according to the vibration order curves of the measuring points, design a vibration absorption and isolation design bolt set according to the vibration measuring points that transmit vibration energy, the radiation sound signals and the noise order curve of the measuring point, and install the vibration absorption and isolation design bolt set on the vibration measuring points that transmit vibration energy to suppress the radiation noise of the motor controller.

[0014] The purpose of the present application is achieved by the following scheme:

[0015] A vibration absorption and isolation design method for an electric drive system, comprising the following steps:

[0016] 1) determining a plurality of vibration measuring points at the connection between the reducer housing and the motor controller housing of the electric drive system, and setting an acceleration sensor at each vibration measuring point, respectively, and collecting the vibration acceleration signals of each vibration measuring point by using the acceleration sensor;

[0017] 2) determining a noise measuring point on the vertical line of the geometric center of the upper cover plate of the motor controller, and setting a microphone at the noise measuring point, and collecting the radiation sound signals of the noise measuring point by using the microphone;

[0018] 3) According to each vibration acceleration signal, a vibration order curve of a measuring point corresponding to the concerned order is constructed, a noise order curve of the measuring point corresponding to the concerned order is constructed according to the radiation sound signal, and the order frequency of the sound pressure excess point is calculated according to the noise order curve of the measuring point;

[0019] 4) The vibration level of the corresponding vibration measuring point is calculated according to the vibration order curve of each measuring point, and a plurality of vibration measuring points that transmit vibration energy are determined according to the vibration level of each vibration measuring point;

[0020] 5) According to the order frequency of the sound pressure excess point, a vibration absorption design frequency is set, and the connection stiffness of the vibration absorption unit is calculated according to the vibration absorption design frequency;

[0021] 6) According to the radiation sound signal collected in step 2), a desired vibration isolation frequency is set, and the total connection stiffness of the vibration isolation unit is calculated according to the desired vibration isolation frequency;

[0022] 7) According to the connection stiffness of the vibration absorption unit, the total connection stiffness of the vibration isolation unit, and the vibration measuring point that transmits vibration energy, a vibration absorption and isolation design bolt assembly capable of being arranged at the connection between the reducer shell and the motor controller shell of the electric drive system for suppressing radiation noise is designed.

[0023] Preferably, in step 3), the specific method for constructing the vibration order curve of the measuring point corresponding to the concerned order according to each vibration acceleration signal, constructing the noise order curve of the measuring point corresponding to the concerned order according to the radiation sound signal, and calculating the order frequency of the sound pressure excess point according to the noise order curve of the measuring point includes:

[0024] 3-1) Collect the motor shaft speed of the electric drive system;

[0025] 3-2) Discrete Fourier transform is performed on the plurality of vibration acceleration signals collected in step 1) and the radiation sound signal collected in step 2) to obtain a plurality of vibration result frequency domain distribution characteristics and an acoustic result frequency domain distribution characteristic;

[0026] 3-3) The concerned order frequency of the corresponding vibration acceleration signal is determined according to each vibration result frequency domain distribution characteristic, and the concerned order value of the corresponding vibration acceleration signal is calculated according to the concerned order frequency of each vibration acceleration signal and the motor shaft speed;

[0027] 3-4) The concerned order frequency of the radiation sound signal is determined according to the acoustic result frequency domain distribution characteristic, and the concerned order value of the radiation sound signal is calculated according to the motor shaft speed and the concerned order frequency of the radiation sound signal;

[0028] 3-5) The vibration order curve of the measuring point corresponding to the concerned order is constructed according to the vibration result frequency domain distribution characteristic and the concerned order value of each vibration acceleration signal;

[0029] 3-6) According to the acoustic result frequency domain distribution characteristics and the concerned order value of the radiation sound signal, the concerned order measurement point noise order curve is constructed;

[0030] 3-7) The measurement point noise order curve is compared with the target line to obtain the order frequency of the sound pressure out-of-tolerance point.

[0031] Preferably, in step 4), the vibration level of the corresponding vibration measurement point is calculated according to the vibration order curve of each measurement point, and the specific mode of determining a plurality of vibration measurement points that transmit vibration energy according to the vibration level of each vibration measurement point comprises:

[0032] 4-1) The vibration level of the corresponding vibration measurement point is calculated according to the vibration order curve of each measurement point;

[0033] 4-2) The vibration level of the vibration measurement point vibration energy sum is calculated according to the vibration level of each vibration measurement point;

[0034] 4-3) According to the vibration level of the vibration measurement point vibration energy sum, each vibration measurement point is judged in the following mode to determine a plurality of vibration measurement points that transmit vibration energy:

[0035] If the vibration energy transmission condition is met, the vibration measurement point does not transmit vibration energy through the installation path;

[0036] If the vibration energy transmission condition is not met, the vibration measurement point transmits vibration energy through the installation path. Preferably, the vibration energy transmission condition is:

[0037] B all B b ≥ 10*log 10 (2*b)

[0038]

[0039] In the formula, B all is the vibration level of the vibration measurement point vibration energy sum, B b is the vibration level of the vibration measurement point, and b is the number of acceleration sensors.

[0040] Preferably, in step 5), according to the order frequency of the sound pressure out-of-tolerance point, a vibration absorption design frequency is set, and the specific mode of calculating the connection stiffness of the vibration absorption unit according to the vibration absorption design frequency comprises:

[0041] 5-1) According to the order frequency of the order point where the sound pressure out-of-tolerance point is located, a vibration absorption design frequency is set for calculating the connection stiffness of the vibration absorption unit;

[0042] 5-2) According to the following formula, the connection stiffness of the vibration absorption unit is calculated in combination with the vibration absorption design frequency:

[0043]

[0044] M t ≥ upper cover plate mass * 10%

[0045] wherein Ω t is the vibration absorbing design frequency, M t is the mass of the vibration absorbing unit, k t is the connection stiffness of the vibration absorbing unit.

[0046] Preferably, in step 6), according to the radiated sound signal collected in step 2), a desired isolation frequency is set, and the specific way of calculating the total connection stiffness of the isolation unit according to the desired isolation frequency comprises:

[0047] 6-1) According to the radiated sound signal collected in step 2), a desired isolation frequency is set, which is used to calculate the isolation stiffness;

[0048] 6-2) According to the desired isolation frequency, the total connection stiffness of the isolation unit is calculated according to the following formula:

[0049] K < M c * Ω 2 / 2

[0050] wherein K is the total connection stiffness, M c is the total mass of the controller assembly, and Ω is the exciting frequency, i.e. the desired minimum isolation frequency.

[0051] Preferably, the design way of the vibration and isolation design bolt set comprises:

[0052] 7-1) Design a vibration and isolation design bolt set, which comprises a vibration absorbing unit and an isolation unit, and the vibration measuring points determined in step 4) for transmitting vibration energy are used as the mounting points of the vibration and isolation design bolt set;

[0053] 7-2) According to the total connection stiffness calculated in step 6), the connection stiffness of a single vibration and isolation design bolt set is calculated;

[0054] 7-3) The stiffness of the vibration absorbing unit of the vibration and isolation design bolt set is set as the connection stiffness of the vibration absorbing unit;

[0055] 7-4) The stiffness of the isolation unit of the vibration and isolation design bolt set is set as the connection stiffness of a single vibration and isolation design bolt set.

[0056] A vibration absorption and isolation design bolt kit comprises an elastic layer, a resonant mass unit, a mounting limiting base, an elastic damping pad and a mounting bolt, the head of the mounting bolt is wrapped by an elastic layer, the elastic layer is wrapped by a resonant mass unit, the lower end of the elastic layer is connected with the mounting limiting base, a through hole is arranged on the elastic damping pad, the tail of the mounting bolt can pass through the through hole to pass through the elastic damping pad, and is connected with the threaded mounting hole arranged on the controller shell and the mounting box body.

[0057] Preferably, the application also relates to a use mode of the vibration absorption and isolation design bolt kit, and specifically comprises the following steps:

[0058] S1) respectively arranging threaded mounting holes on the controller shell and the mounting box body;

[0059] S2) placing the elastic damping pad between the controller shell and the mounting box body, and aligning the through hole of the elastic damping pad with the threaded mounting hole of the controller shell and the threaded mounting hole of the mounting box body;

[0060] S3) making the mounting bolt pass through the threaded mounting hole of the controller shell, the through hole of the elastic damping pad and the threaded mounting hole of the mounting box body in sequence, and tightening the mounting bolt until the mounting limiting base is in close contact with the controller shell.

[0061] The application has the following beneficial effects:

[0062] A vibration absorption and isolation design method for an electric drive system comprises the following steps:

[0063] 1) determining a plurality of vibration measuring points at the connection between the reducer shell of the electric drive system and the motor controller shell, arranging an acceleration sensor at each vibration measuring point, and respectively collecting vibration acceleration signals of the vibration measuring points by using the acceleration sensors;

[0064] 2) determining a noise measuring point on the vertical line of the geometric center of the upper cover plate of the motor controller, arranging a microphone at the noise measuring point, and collecting a radiation sound signal of the noise measuring point by using the microphone;

[0065] 3) respectively constructing vibration order curves of the measuring points corresponding to the concerned orders according to the vibration acceleration signals, constructing noise order curves of the measuring points corresponding to the concerned orders according to the radiation sound signal, and calculating the order frequency of the sound pressure excess point according to the noise order curves of the measuring points;

[0066] 4) calculating the vibration levels of the corresponding vibration measuring points according to the vibration order curves of the measuring points, and determining a plurality of vibration measuring points for transmitting vibration energy according to the vibration levels of the vibration measuring points;

[0067] 5) setting a vibration absorption design frequency according to the order frequency of the sound pressure excess point, and calculating the connection stiffness of the vibration absorption unit according to the vibration absorption design frequency.

[0068] 6) According to the radiation sound signal collected in step 2), an expected isolation frequency is set, and the total connecting stiffness of the isolation unit is calculated according to the expected isolation frequency;

[0069] 7) According to the connecting stiffness of the vibration absorption unit, the total connecting stiffness of the isolation unit, and the vibration measuring point of the transmitted vibration energy, a vibration absorption and isolation design bolt set capable of being arranged at the connecting position of the reducer shell and the motor controller shell of the electric drive system is designed to suppress the radiation noise.

[0070] The present application collects the vibration acceleration signal and the radiation sound signal of the motor controller, constructs a plurality of vibration order curves of the measuring point of the concerned order and a noise order curve of the measuring point of the concerned order, determines the vibration measuring point of the transmitted vibration energy according to the vibration order curve of the measuring point, and designs a vibration absorption and isolation design bolt set according to the radiation sound signal, the noise order curve of the measuring point, and the vibration measuring point of the transmitted vibration energy, which can be used to suppress the radiation noise of the motor controller.

[0071] Preferably, in step 4), the vibration level of the corresponding vibration measuring point is calculated according to each vibration order curve of the measuring point, and the specific manner of determining a plurality of vibration measuring points of the transmitted vibration energy according to the vibration level of each vibration measuring point includes:

[0072] 4-1) The vibration level of the corresponding vibration measuring point is calculated according to each vibration order curve of the measuring point;

[0073] 4-2) The vibration level of the vibration measuring point vibration energy sum is calculated according to the vibration level of each vibration measuring point;

[0074] 4-3) According to the vibration level of the vibration measuring point vibration energy sum, each vibration measuring point is judged in the following manner to determine a plurality of vibration measuring points of the transmitted vibration energy:

[0075] If the vibration energy transmission condition is met, the vibration measuring point does not transmit vibration energy through the installation path;

[0076] If the vibration energy transmission condition is not met, the vibration measuring point transmits vibration energy through the installation path.

[0077] Preferably, the vibration energy transmission condition is:

[0078] B all B b ≥ 10*log 10 (2*b)

[0079]

[0080] In the formula, B all is the vibration level of the vibration measuring point vibration energy sum, and B bL is the vibration level of the vibration measuring point, b is the number of acceleration sensors.

[0081] The present application proposes a scientific determination method of the sound radiation super-difference point frequency. By systematically analyzing the path vibration transmission characteristics of each installation point of the super-difference point controller, the influence degree of different vibration transmission paths on the sound radiation of the controller can be quantitatively evaluated. This innovation breaks through the fuzzy cognition of the relationship between vibration and sound radiation in traditional design, provides accurate theoretical basis for optimizing the controller layout and vibration suppression strategy, and effectively improves the pertinence and effectiveness of sound radiation control.

[0082] Preferably, in step 5), according to the order frequency of the sound pressure super-difference point, a vibration absorption design frequency is set, and the specific way of calculating the connection stiffness of the vibration absorption unit according to the vibration absorption design frequency includes:

[0083] 5-1) According to the order frequency of the order point where the sound pressure super-difference point is located, a vibration absorption design frequency is set for calculating the connection stiffness of the vibration absorption unit;

[0084] 5-2) According to the following formula, the connection stiffness of the vibration absorption unit is calculated in combination with the vibration absorption design frequency:

[0085]

[0086] M t ≥ Upper cover plate mass * 10%

[0087] In the formula, Ω t is the vibration absorption design frequency, M t is the mass of the vibration absorption unit, and k t is the connection stiffness of the vibration absorption unit.

[0088] Preferably, in step 6), according to the radiation sound signal collected in step 2), a desired vibration isolation frequency is set, and the specific way of calculating the total connection stiffness of the vibration isolation unit according to the desired vibration isolation frequency includes:

[0089] 6-1) According to the radiation sound signal collected in step 2), a desired vibration isolation frequency is set for calculating the vibration isolation stiffness;

[0090] 6-2) According to the following formula, the total connection stiffness of the vibration isolation unit is calculated in combination with the desired vibration isolation frequency:

[0091] K < M c * Ω 2 / 2

[0092] In the formula, K is the total connection stiffness, M c is the mass of the controller assembly, and Ω is the exciting frequency, i.e. the desired minimum vibration isolation frequency.

[0093] The application designs the connecting stiffness of the vibration absorbing unit and the vibration isolation unit according to the peak frequency of the sound pressure super-difference point, and through the design of the connecting stiffness of the vibration absorbing unit, the vibration absorbing unit can accurately match and offset the vibration energy, and through the design of the connecting stiffness of the vibration isolation unit, the vibration isolation unit can efficiently block the transmission of vibration to the surrounding structure.

[0094] The application discloses an absorbing and isolating vibration design bolt kit, which comprises an elastic layer, a resonant mass unit, a mounting limiting base, an elastic damping pad and a mounting bolt.

[0095] Preferably, the application also relates to a use mode of the absorbing and isolating vibration design bolt kit, and specifically comprises the following steps.

[0096] S1) respectively arranging threaded mounting holes on the controller housing and the mounting box body;

[0097] S2) placing the elastic damping pad between the controller housing and the mounting box body, and aligning the through hole of the elastic damping pad with the threaded mounting hole of the controller housing and the threaded mounting hole of the mounting box body;

[0098] S3) sequentially passing the mounting bolt through the threaded mounting hole of the controller housing, the through hole of the elastic damping pad and the threaded mounting hole of the mounting box body, and tightening the mounting bolt until the mounting limiting base is in close contact with the controller housing.

[0099] The application discloses an absorbing and isolating vibration design bolt kit, which comprises an elastic layer, a resonant mass unit, a mounting limiting base, an elastic damping pad and a mounting bolt.

[0100] The application has the following advantages:

[0101] By analyzing the vibration acceleration signal and the radiation sound signal of the motor controller, a plurality of vibration order curves of measuring points and a noise order curve of a measuring point are constructed, a vibration measuring point for transmitting vibration energy is determined according to the vibration order curve of the measuring point, and an absorbing and isolating vibration design bolt kit is designed according to the vibration measuring point for transmitting vibration energy, the radiation sound signal and the noise order curve of the measuring point.

[0102] ①The present application constructs multiple vibration order curves of measuring points and a noise order curve of a measuring point by analyzing the vibration acceleration signal and the radiation sound signal of the motor controller, and determines a vibration measuring point that transmits vibration energy according to the vibration order curve of the measuring point, and designs a vibration absorption and isolation design bolt set according to the vibration measuring point that transmits vibration energy, the radiation sound signal and the noise order curve of the measuring point, so that the radiation noise of a large area of sound radiation such as a motor controller is effectively suppressed, and important technical support is provided for improving the NVH (noise, vibration and sound roughness) performance and reliability of the system.

[0103] ②The present application quickly designs the connection stiffness of the vibration absorption unit and the vibration isolation unit according to the frequency of the sound pressure excess point, can accurately match and offset the vibration energy of a specific frequency, and efficiently blocks the transmission of vibration to the surrounding structure, not only shortens the research and development period of radiation noise suppression, but also reduces the research and development cost, so that the vibration control scheme can be more flexibly adapted to different application scenarios, and the feasibility and efficiency in engineering practice are significantly improved.

[0104] ③The present application proposes a vibration absorption and isolation design bolt set with simple structure and convenient operation, which provides an embodiment tool for the vibration absorption and isolation design method for the electric drive system. The vibration absorption and isolation design bolt set can simplify the design process and reduce the operation difficulty through reasonable structure layout and function integration, so that even non-professionals can quickly complete the suppression of the sound radiation noise of the motor controller with the help of the device.

[0105] Nomenclature

[0106] Sound radiation: Sound radiation refers to the phenomenon that a sound source emits sound waves into the surrounding medium. When the sound source vibrates, it causes the vibration of the surrounding medium (such as air, water, etc.), forming sound waves and propagating to a distance.

[0107] Radiated noise: Radiated noise refers to the noise produced by sound waves radiated from various sound sources into the surrounding environment. It is a common source of environmental pollution, which can cause adverse effects on people's life, work and health.

[0108] Vibration order curve: It is a curve used to describe the vibration characteristics of rotating machinery, which reflects the relationship between vibration response and rotating component speed. By analyzing the vibration order curve, engineers can determine the source and cause of vibration.

[0109] Noise order curve of measuring point: It is a curve that describes the change of noise characteristics with rotating component speed at a specific measuring point. It is obtained by analyzing the noise signal through order analysis method, and the relationship between noise amplitude and order and speed is presented in the form of curve, which is helpful for analyzing the source and propagation path of noise.

[0110] Vibration absorption: is the core technology concept in the field of vibration control, refers to the system strategy of vibration suppression through the synergistic mechanism of energy dissipation and transmission block. Among them, "vibration absorption" refers to the use of tuned absorber, viscoelastic material and other devices or structures to convert vibration energy into heat energy or other forms of energy, so as to attenuate the vibration response of specific frequency or frequency band; "vibration isolation" is to block the transmission path of vibration from the vibration source to the surrounding structure or environment by optimizing the support structure, configuring the vibration isolator, etc., to reduce the vibration transmission rate. The two form a complement in the electric drive system: the vibration absorption technology targets the vibration energy of the key frequency for targeted absorption, solving the problem of resonance amplification; the vibration isolation technology cuts off the vibration propagation from the transmission path, reducing the spread of vibration to the non-desired area.

[0111] Concerned surface: "concerned surface" refers to a specific surface area in the electric drive system that needs to be analyzed for its sound radiation contribution.

[0112] Concerned order: "concerned order" refers to the specific vibration order that users focus on in the vibration noise analysis of the electric drive system. These orders are usually directly related to the key excitation sources inside the system (such as gear meshing, electromagnetic force, rotating part imbalance, etc.), and are the core parameters for locating noise sources and quantifying transmission paths.

[0113] Concerned order sound pressure curve: the actual noise order curve, the overage point is the position where the actual noise curve exceeds the design target order curve, and the order point is the frequency at which the overage point is located.

[0114] Target line: a pre-set order curve with design target, which can be understood as an ideal order noise curve, used as a reference standard for product actual order noise curve design, and the product actual order noise curve is usually designed to be lower than this curve. However, during the design process, the actual noise order line of some frequency points may be higher than the target order line. In this invention, the target line can be considered as the design target order line. BRIEF DESCRIPTION OF DRAWINGS

[0115] Figure 1 is the flowchart of the present invention;

[0116] Figure 2 is the schematic diagram of acoustic measurement point arrangement in the embodiment of the present invention;

[0117] Figure 3 is the schematic diagram of vibration acceleration measurement point arrangement in the embodiment of the present invention;

[0118] Figure 4 is the working schematic diagram of the dynamic vibration absorber in the embodiment of the present invention;

[0119] Figure 5 is a controller-box mounting point multi-rigidity equivalent schematic diagram in an embodiment of the present application;

[0120] Figure 6 is a controller-box mounting point single-rigidity equivalent schematic diagram in an embodiment of the present application;

[0121] Figure 7 is a structural schematic diagram of a vibration absorption and isolation design bolt kit of the present application;

[0122] Figure 8 is a sound pressure level curve of a microphone 25 cm away from a front cover plate in a vibration absorption and isolation design;

[0123] Figure 9 is a vibration level curve of a vibration measuring point near a front mounting point in a vibration absorption and isolation design;

[0124] Figure 10 is a sound pressure level curve of a microphone 25 cm away from a rear cover plate in a vibration absorption and isolation design;

[0125] Figure 11 is a vibration level curve of a vibration measuring point near a rear mounting point in a vibration absorption and isolation design. DETAILED DESCRIPTION

[0126] As Figures 1 to 11 shown in the figure, a vibration absorption and isolation design method for an electric drive system comprises the following steps:

[0127] 1) determining a plurality of vibration measuring points at the connection between the reducer housing and the motor controller housing of the electric drive system, and setting an acceleration sensor at each vibration measuring point, respectively, and using the acceleration sensors to collect vibration acceleration signals of the respective vibration measuring points;

[0128] 2) determining a noise measuring point on the vertical line of the geometric center of the motor controller upper cover plate, and setting a sound receiver at the noise measuring point, and using the sound receiver to collect the radiated sound signal of the noise measuring point;

[0129] 3) constructing a measuring point vibration order curve corresponding to the concerned order according to the respective vibration acceleration signals, constructing a measuring point noise order curve of the concerned order according to the radiated sound signal, and calculating the order frequency of the sound pressure excess point according to the measuring point noise order curve;

[0130] 4) calculating the vibration level of the corresponding vibration measuring point according to the respective measuring point vibration order curves, and determining a plurality of vibration measuring points that transfer vibration energy according to the vibration levels of the respective vibration measuring points;

[0131] 5) setting a vibration absorption design frequency according to the order frequency of the sound pressure excess point, and calculating the vibration absorption unit connection rigidity according to the vibration absorption design frequency;

[0132] 6) Based on the radiated acoustic signal collected in step 2), set an expected vibration isolation frequency, and calculate the total connection stiffness of the vibration isolation unit based on the expected vibration isolation frequency.

[0133] 7) Based on the connection stiffness of the vibration absorption unit, the total connection stiffness of the vibration isolation unit, and the vibration measurement points that transmit vibration energy, design a vibration absorption and isolation bolt kit that can be installed at the connection between the reducer housing and the motor controller housing of the electric drive system to suppress radiated noise.

[0134] The following is an example of implementing the method described above:

[0135] 1) Excitation identification of the electric drive system can be performed using experimental or simulation methods. During the experiment, four vibration measurement points are determined at the connection between the reducer housing and the motor controller housing of the electric drive system, and an acceleration sensor is installed at each vibration measurement point. Figure 2 As shown, the shortest distance between the geometric center of the accelerometer mounting surface and the outer diameter of the mounting hole does not exceed 10mm, and the unit of vibration acceleration is m / s². 2 Vibration acceleration signals at each vibration measurement point were collected using accelerometers. Each sensor collected vibration acceleration signals in the X, Y, and Z directions, denoted as a. bx a by a bz In the formula, b represents the installation point number of the controller and the reducer.

[0136] 2) Let the minimum outer envelope spherical radius of the electric drive assembly be R. Determine a noise measurement point on the vertical line from the geometric center of the motor controller's upper cover. The distance of this noise measurement point from the center of the minimum envelope spherical surface of the assembly should be greater than R and less than R+10mm. This distance is considered sufficient to comprehensively measure the radiated sound from the main radiation surfaces of the controller, while being less affected by the radiated sound from other surfaces. The sound pressure unit is Pa. A microphone is placed at the noise measurement point, such as... Figure 3 As shown, a microphone is used to collect the radiated sound signal at the noise measurement point;

[0137] 3) Based on each vibration acceleration signal, construct the vibration order curves of the measurement points corresponding to the order of interest; based on the radiated sound signal, construct the noise order curves of the measurement points corresponding to the order of interest; and calculate the order frequency of the sound pressure deviation point based on the noise order curves of the measurement points. Specific methods include:

[0138] 3-1) Collect the motor shaft speed of the electric drive system;

[0139] 3-2) Perform discrete Fourier transform on the several vibration acceleration signals collected in step 1) and the radiated acoustic signals collected in step 2) respectively to obtain the frequency domain distribution characteristics of several vibration results and the frequency domain distribution characteristics of one acoustic result.

[0140] The formula for the Discrete Fourier Transform is:

[0141]

[0142] In the formula, X k x is a frequency domain value. n For discrete time domain values, N is the signal length, k is the frequency domain discrete variable, n is the time domain discrete variable, and i is the imaginary unit;

[0143] It is worth noting that if the frequency domain result can be obtained directly, step 3-2) can be skipped.

[0144] 3-3) Based on the frequency domain distribution characteristics of each vibration result, determine the order of interest frequency of the corresponding vibration acceleration signal. According to the following formula, calculate the order of interest value of the corresponding vibration acceleration signal based on the order of interest frequency of each vibration acceleration signal and the motor shaft speed.

[0145]

[0146] In the formula, f is the frequency of interest of the vibration acceleration signal at the current speed, p is the value of interest, and s is the motor shaft speed;

[0147] 3-4) Based on the frequency domain distribution characteristics of the acoustic results, determine the frequencies of interest for the radiated acoustic signal, and calculate the order of interest value of the radiated acoustic signal based on the motor shaft speed and the frequencies of interest for the radiated acoustic signal:

[0148]

[0149] In the formula, f is the frequency of interest of the radiated sound signal at the current speed, p is the value of interest, and s is the motor shaft speed (in rpm).

[0150] 3-5) Based on the frequency domain distribution characteristics of the vibration results of each vibration acceleration signal and the corresponding order of interest, construct the vibration order curve of the measurement point of interest.

[0151] 3-6) Based on the frequency domain distribution characteristics of the acoustic results and the order of interest of the radiated acoustic signal, construct the noise order curve of the measurement point of interest;

[0152] 3-7) Compare the noise order curve at the measurement point (i.e., the sound pressure curve of the order of interest) with the corresponding target line to obtain the order point f where the sound pressure exceeds the limit. pc .

[0153] Based on the comparison between the calculation results and the target line, the electric drive system exhibits an out-of-tolerance point at gear meshing order 6.85, with the peak deviation occurring at 3300 rpm. Figure 8 As shown, from the formula The calculated off-point frequency is 376.75 Hz.

[0154] In this embodiment, a design target order curve, i.e. an ideal order noise curve, is usually set in advance in the design process, and the actual order noise curve of the product needs to be designed to be lower than the curve. However, in the design process, the actual noise order curve of some frequency points is often higher than the target order curve. In the description, the target curve is the design target order curve, the concerned order sound pressure curve is the actual noise order curve, the out-of-tolerance point is the position where the actual noise curve is higher than the design target order curve, and the order point is the frequency of the out-of-tolerance point.

[0155] 4) According to the vibration order curve of each measuring point, the vibration level of the corresponding vibration measuring point is calculated, and according to the vibration level of each vibration measuring point, a plurality of vibration measuring points for transmitting vibration energy are determined, and the specific method comprises:

[0156] 4-1) According to the vibration order curve of each measuring point, the vibration level of the corresponding vibration measuring point is calculated:

[0157]

[0158] In the formula, B b is the vibration level of the vibration measuring point, a bx is the vibration acceleration in the X direction collected by the bth sensor, a by is the vibration acceleration in the Y direction collected by the bth sensor, a bz is the vibration acceleration in the Z direction collected by the bth sensor, and e is the abbreviation of exponent in scientific notation, which is used to represent the power of 10.

[0159] 4-2) According to the vibration level of each vibration measuring point, the vibration level of the sum of the vibration energy of all vibration measuring points is calculated;

[0160] 4-3) According to the vibration level of the sum of the vibration energy of all vibration measuring points, each vibration measuring point is judged in the following manner to determine a plurality of vibration measuring points for transmitting vibration energy:

[0161] If the vibration energy transmission condition is met, the vibration measuring point does not transmit vibration energy through the path;

[0162] If the vibration energy transmission condition is not met, the vibration measuring point transmits vibration energy through the path.

[0163] In this embodiment, the vibration energy transmission condition is:

[0164] B all -B b ≥ 10*log 10 (2*b)

[0165]

[0166] B all is the vibration level of the vibration energy sum of all vibration measuring points, B b is the vibration level of the vibration measuring point, and b is the number of acceleration sensors.

[0167] The vibration contribution degree of each vibration measuring point 25 order vibration order curve is calculated by Figure 10 It can be obtained that the four vibration measuring points D a The difference is consistent with the above formula, and it is considered that the four paths all contribute to the controller 376.75Hz sound radiation.

[0168] 5) According to the order frequency of the sound pressure excess point, set a vibration absorption design frequency, and calculate the connection stiffness of the vibration absorption unit according to the vibration absorption design frequency, which includes the following specific ways:

[0169] 5-1) According to the frequency of the order point where the sound pressure excess point is located, set a vibration absorption design frequency for calculating the connection stiffness of the vibration absorption unit;

[0170] 5-2) Combined with the vibration absorption design frequency, the connection stiffness of the vibration absorption unit is calculated according to the following formula:

[0171]

[0172] M t ≥10% of the mass of the upper cover plate

[0173] In the formula, Ω t is the vibration absorption design frequency, M t is the mass of the vibration absorption unit, k t is the connection stiffness of the vibration absorption unit.

[0174] The actual mass of the upper cover plate is 0.98kg, and considering the actual installation position size and material limitation M t The mass is designed as a 0.1kg lead block, and the vibration absorption design frequency Ω t is set to 2*π*376.75, and the corresponding k t is designed to be 0.1*(2*π*376.75) 2 ≈560358.8N / m.

[0175] 6) According to the radiation sound signal collected in step 2), set a desired vibration isolation frequency, and calculate the total connection stiffness of the vibration isolation unit according to the desired vibration isolation frequency, which includes the following specific ways:

[0176] Since the stiffness of the designed vibration isolation unit (i.e. the stiffness of the elastic damping pad) is much smaller than the stiffness of the controller and the shell, the controller, the shell and the vibration isolation unit can be considered as a multi-point parallel spring mass unit, as shown in Figure 5 The total mass of the controller assembly is M c, total connection stiffness K = k1 + k2… + kn n , where k n represents the vibration isolation stiffness of a controller and a mounting box at a connection point, and n represents the number of connection points, so the controller and the mounting box can be regarded as a spring-mass-damper unit under the bottom excitation condition as shown in the following formula Figure 6 , and the vibration isolation stiffness is designed based on the passive vibration isolation principle as follows:

[0177] 6-1) According to the radiation sound signal collected in step 2), an expected vibration isolation frequency is set for calculating the vibration isolation stiffness;

[0178] 6-2) According to the expected vibration isolation frequency, the vibration isolation stiffness is calculated according to the following formula:

[0179] K < M c * Ω 2 / 2

[0180] , where K is the total connection stiffness, M c is the total mass of the controller assembly, and Ω is the expected vibration isolation frequency (i.e. the excitation frequency, the expected minimum vibration isolation frequency).

[0181] The design vibration isolation frequency is 200 Hz, the expected vibration isolation frequency is designed as 2 * π * 200 Hz, M c = 10 kg, K < (10 * (2 * π * 200) 2 ) / 2 ≈ 7895683.5 N / m, and the stiffness of a single elastic damping pad (i.e. the total connection stiffness / the number of vibration measuring points for transmitting vibration energy) is about 1973920.9 N / m.

[0182] 7) According to the connection stiffness of the vibration absorption unit, the total connection stiffness of the vibration isolation unit, and the vibration measuring points for transmitting vibration energy, a vibration absorption and isolation design bolt set capable of being arranged at the connection between the reducer housing of the electric drive system and the motor controller housing for suppressing the radiation noise is designed in the following manner:

[0183] 7-1) A vibration absorption and isolation design bolt set is designed, which includes a vibration absorption unit and a vibration isolation unit, and a plurality of vibration measuring points for transmitting vibration energy determined in step 4) are used as mounting points of the vibration absorption and isolation design bolt set, and the number of vibration measuring points for transmitting vibration energy is used as the number of vibration absorption and isolation design bolt sets;

[0184] 7-2) According to the total connection stiffness calculated in step 6) and the number of mounting points of the vibration absorption and isolation design bolt set determined in step 7-1), the connection stiffness of a single vibration absorption and isolation design bolt set is calculated in the following manner:

[0185] The connection stiffness of a single vibration absorption and isolation design bolt set = the total connection stiffness / the number of vibration absorption and isolation design bolt sets.

[0186] 7-3) Set the stiffness of the vibration absorption unit of the vibration absorption and isolation design bolt kit to the connection stiffness of the vibration absorption unit;

[0187] 7-4) Set the stiffness of the vibration isolation unit of the vibration absorption and isolation design bolt kit to the connection stiffness of the individual vibration absorption and isolation design bolt kit.

[0188] The vibration absorption and isolation design bolt kit obtained in the above manner comprises an elastic layer 1, a resonant mass unit 2, a mounting limiting base 3, an elastic damping pad 4, and a mounting bolt 5. The head of the mounting bolt 5 is wrapped by an elastic layer 1, the elastic layer 1 is wrapped by a resonant mass unit 2, the lower end of the elastic layer 1 is connected with the mounting limiting base 3, and a through hole is arranged on the elastic damping pad 4, so that the tail of the mounting bolt 5 can pass through the through hole and pass through the elastic damping pad 4 to be connected with the threaded mounting hole arranged on the controller shell and the mounting box body.

[0189] The elastic damping pad is a vibration isolation unit of the vibration absorption and isolation design bolt kit, and is a device for reducing vibration transmission and absorbing vibration energy, which is made of elastic materials such as rubber, polyurethane, and spring. The working principle is to absorb and dissipate vibration energy through the deformation of the elastic material, convert the vibration generated by the equipment or structure into elastic potential energy, thereby reducing the amplitude and transmission efficiency of the vibration, and reducing the influence of the vibration on the surrounding environment, the equipment itself, and personnel.

[0190] The mounting bolt is used for connecting and fixing mechanical parts of various components or equipment.

[0191] The elastic layer is a vibration absorption unit of the vibration isolation unit of the vibration absorption and isolation design bolt kit, and mainly plays a role of elastic buffering and vibration reduction. It can absorb vibration energy and reduce the transmission of vibration to other components or structures through the bolt kit, thereby reducing the propagation and influence of the vibration. At the same time, the elastic layer can also provide a certain flexibility to adapt to different installation conditions and vibration situations.

[0192] The resonant mass unit is an object or component with a certain mass that can reciprocate at a specific frequency under the action of elastic force or other restoring force.

[0193] It is worth noting that in actual use, the resonant mass unit of the vibration absorption and isolation design bolt kit can be provided with multiple resonant mass units with different masses in the longitudinal direction according to the number of vibration absorption frequencies (i.e., the number of specific frequencies at which the resonant mass unit can effectively absorb vibration energy) and in combination with the spatial position of the vibration absorption and isolation design bolt kit, so as to meet different vibration energy absorption requirements. In the present embodiment, only one resonant mass unit is designed for the vibration absorption and isolation design bolt kit.

[0194] The mounting compression ring is a ring-shaped device for fixing an object or component at a specific position and keeping it in a tightly connected or stable state by applying pressure.

[0195] In the embodiment, the specific way of designing the vibration-absorbing and vibration-isolating design bolt set according to the connection stiffness of the vibration-absorbing unit and the vibration-isolating stiffness of the vibration-isolating unit is as follows: the stiffness of the elastic layer 1 of the vibration-absorbing and vibration-isolating design bolt set is set as the connection stiffness of the vibration-absorbing unit, and the stiffness of the elastic vibration-absorbing pad 4 of the vibration-absorbing and vibration-isolating design bolt set is set as the vibration-isolating stiffness of the vibration-isolating unit. The use mode of the vibration-absorbing and vibration-isolating design bolt set specifically includes:

[0196] S1) respectively arranging threaded mounting holes on the controller housing and the mounting box;

[0197] S2) placing the elastic vibration-absorbing pad 4 between the controller housing and the mounting box, and aligning the threaded mounting holes of the elastic vibration-absorbing pad 4 with the threaded mounting holes of the controller housing and the mounting box;

[0198] S3) making the mounting bolt 5 pass through the threaded mounting holes of the controller housing, the elastic vibration-absorbing pad 4 and the mounting box in sequence, and tightening the mounting bolt 5 until the mounting limiting base 3 is in close contact with the controller housing.

[0199] It is worth noting that the four vibration measuring points determined in the embodiment at the connection between the reducer housing and the motor controller housing of the electric drive system all have ordinary bolts for fixed connection of the reducer housing and the motor controller housing. After the vibration measuring points that transmit vibration energy are determined, the ordinary bolts on the vibration measuring points that transmit vibration energy can be directly replaced by the designed vibration-absorbing and vibration-isolating design bolt set. That is, the vibration-absorbing and vibration-isolating design bolt set of the embodiment does not need to additionally open threaded mounting holes on the reducer housing and the motor controller housing, but can be directly installed on the bolt mounting holes that originally exist on the reducer housing and the motor controller housing, which is very convenient to use.

[0200] In the embodiment, the elastic vibration-absorbing pad is installed between the controller housing and the combined surface of the motor and the threaded mounting hole of the reducer housing, the mounting compression ring is tightly combined with the non-housing contact surface of the threaded mounting hole of the controller housing, the elastic vibration-absorbing pad is pre-tightened and the displacement of the controller housing is limited, the transmission of vibration energy between the motor and the reducer housing is reduced, the mounting compression ring and the mounting bolt are tightly connected with the resonant mass unit through high-damping elastic materials such as vulcanized rubber, and the vibration-absorbing unit absorbs vibration energy in the designed vibration-absorbing frequency band.

[0201] As Figure 10 , Figure 11As shown, the bolt assembly designed by the vibration absorption and isolation design method can greatly suppress the area with large radiation sound in the electric drive system, such as the radiation noise of the motor controller, for example:

[0202] Before the bolt assembly designed in the embodiment is installed, the sound pressure level curve of the microphone at the position of 25 cm from the cover plate is as shown in the following figure:

[0203] Before the vibration absorption and isolation design, the vibration level curve of the measuring point near the mounting point is as shown in the following figure: Figure 8 As shown, Figure 8 The 6.85 order sound pressure order curve is seriously over-standard at 3300 rpm, and the sound pressure level at the position of 0.25 m above the controller cover plate is about 82.5 dB;

[0204] Before the vibration absorption and isolation design, the vibration level curve of the measuring point near the mounting point is as shown in the following figure: Figure 9 As shown, Figure 9 The vibration measuring point order curve is the same order, and the four measuring points are different at the frequency point of 376.75 Hz. a If the differences are consistent with the above formula, it is considered that the four paths all contribute to the sound radiation of the controller at 376.75 Hz.

[0205] After the bolt assembly designed in the embodiment is installed,

[0206] After the vibration absorption and isolation design, the sound pressure level curve of the microphone at the position of 25 cm from the cover plate (i.e. the sound pressure level result at the position of 0.25 m above the controller cover plate) is as shown in the following figure: Figure 10 As shown, Figure 8 After the vibration absorption and isolation design, the sound pressure level of the 6.85 order sound pressure order curve at the frequency point of 3300 rpm is reduced by about 13 dB.

[0207] After the vibration absorption and isolation design, the vibration level curve of the measuring point near the mounting point is as shown in the following figure: Figure 11 As shown, Figure 9 The vibration level of the measuring point before the vibration isolation design, Figure 11 The vibration level of the measuring point after the vibration isolation design, it can be seen that after the vibration isolation design, the peak value of the vibration level is reduced from 145 dB to 136 dB in the frequency band above the design vibration isolation frequency of 200 Hz, the vibration level is reduced by 5-20 dB in the frequency band above 200 Hz, and the vibration isolation effect is obvious.

[0208] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and the changes made by those skilled in the art without departing from the spirit of the present application fall within the protection scope of the present application.

Claims

1. A method for an electric drive system with an active vibration isolation design, characterized by The method comprises the following steps: 1) determining a plurality of vibration measuring points at the connection between the reducer housing and the motor controller housing of the electric drive system, and setting an acceleration sensor at each vibration measuring point, respectively collecting the vibration acceleration signals of each vibration measuring point by using the acceleration sensors; 2) determining a noise measuring point on the vertical line of the geometric center of the motor controller upper cover plate, and setting a microphone at the noise measuring point, collecting the radiated sound signals of the noise measuring point by using the microphone; 3) constructing the vibration order curve of the measuring point corresponding to the concerned order according to each vibration acceleration signal, constructing the noise order curve of the measuring point corresponding to the concerned order according to the radiated sound signal, and calculating the order frequency of the sound pressure excess point according to the noise order curve of the measuring point; 4) calculating the vibration level of the corresponding vibration measuring point according to the vibration order curve of each measuring point, and determining a plurality of vibration measuring points that transmit vibration energy according to the vibration level of each vibration measuring point; 5) setting a vibration absorption design frequency according to the order frequency of the sound pressure excess point, and calculating the connection stiffness of the vibration absorption unit according to the vibration absorption design frequency; 6) setting an expected vibration isolation frequency according to the radiated sound signal collected in step 2), and calculating the total connection stiffness of the vibration isolation unit according to the expected vibration isolation frequency; 7) designing a vibration absorption and isolation design bolt set capable of being arranged at the connection between the reducer housing and the motor controller housing of the electric drive system for inhibiting radiated noise according to the connection stiffness of the vibration absorption unit, the total connection stiffness of the vibration isolation unit, and the vibration measuring points that transmit vibration energy.

2. The design method of claim 1, wherein In step 3), the vibration order curve of the measuring point corresponding to the concerned order is constructed according to each vibration acceleration signal, the noise order curve of the measuring point corresponding to the concerned order is constructed according to the radiated sound signal, and the order frequency of the sound pressure excess point is calculated according to the noise order curve of the measuring point. The specific method comprises: 3-1) collecting the motor shaft speed of the electric drive system; 3-2) performing discrete Fourier transform on the plurality of vibration acceleration signals collected in step 1) and the radiated sound signal collected in step 2) to obtain a plurality of vibration result frequency domain distribution characteristics and an acoustic result frequency domain distribution characteristic; 3-3) determining the concerned order frequency of the corresponding vibration acceleration signal according to each vibration result frequency domain distribution characteristic, and calculating the concerned order value of the corresponding vibration acceleration signal according to the concerned order frequency of each vibration acceleration signal and the motor shaft speed; 3-4) determining the concerned order frequency of the radiated sound signal according to the acoustic result frequency domain distribution characteristic, and calculating the concerned order value of the radiated sound signal according to the motor shaft speed and the concerned order frequency of the radiated sound signal; 3-5) constructing the vibration order curve of the measuring point corresponding to the concerned order according to the vibration result frequency domain distribution characteristic and the concerned order value of each vibration acceleration signal; 3-6) constructing the noise order curve of the measuring point corresponding to the concerned order according to the acoustic result frequency domain distribution characteristic and the concerned order value of the radiated sound signal; 3-7) comparing the noise order curve of the measuring point with the target line to obtain the order frequency of the sound pressure excess point.

3. The design method of claim 1, wherein In step 4), the vibration level of each vibration measuring point is calculated according to the vibration order curve of each measuring point, and a plurality of vibration measuring points transmitting vibration energy are determined according to the vibration level of each vibration measuring point, and the specific method comprises: 4-1) The vibration level of each vibration measuring point is calculated according to the vibration order curve of each measuring point; 4-2) The vibration level of the sum of the vibration energy of the vibration measuring points is calculated according to the vibration level of each vibration measuring point; 4-3) According to the vibration level of the sum of the vibration energy of the vibration measuring points, each vibration measuring point is judged in the following manner to determine a plurality of vibration measuring points transmitting vibration energy: If the vibration energy transmission condition is met, the vibration measuring point does not transmit vibration energy through the installation path; If the vibration energy transmission condition is not met, the vibration measuring point transmits vibration energy through the installation path.

4. The design method of claim 3, wherein The vibration energy transmission condition is: B all -B b ≥10*log 10 (2*b) In the formula, B all is the vibration level of the vibration energy sum of the vibration measuring point, B b is the vibration level of the vibration measuring point, and b is the number of acceleration sensors.

5. The design method of claim 1, wherein In step 5), a vibration absorption design frequency is set according to the order frequency of the sound pressure excess point, and the connection stiffness of the vibration absorption unit is calculated according to the vibration absorption design frequency, and the specific method comprises: 5-1) A vibration absorption design frequency is set according to the order frequency of the order point where the sound pressure excess point is located, which is used to calculate the connection stiffness of the vibration absorption unit; 5-2) The connection stiffness of the vibration absorption unit is calculated according to the following formula combined with the vibration absorption design frequency: M t ≥ upper cover mass * 10% In the formula, Ω t is the design frequency of the vibration absorption, M t is the mass of the vibration absorption unit, k t is the connection stiffness of the vibration absorption unit.

6. The design method of claim 1, wherein In step 6), a desired vibration isolation frequency is set according to the radiation sound signal collected in step 2), and the total connection stiffness of the vibration isolation unit is calculated according to the desired vibration isolation frequency, and the specific method comprises: 6-1) A desired vibration isolation frequency is set according to the radiation sound signal collected in step 2), which is used to calculate the vibration isolation stiffness; 6-2) The total connection stiffness of the vibration isolation unit is calculated according to the following formula combined with the desired vibration isolation frequency: K < M c * Ω 2 / 2 where K is the total connected stiffness, M c is the controller assembly mass, and Ω is the excitation frequency.

7. The design method of claim 1, wherein In step 7), the design method of the vibration absorption and isolation design bolt set comprises: 7-1) A vibration absorption and isolation design bolt set is designed, which comprises a vibration absorption unit and a vibration isolation unit, and the plurality of vibration measuring points transmitting vibration energy determined in step 4) are used as the installation points of the vibration absorption and isolation design bolt set; 7-2) The connection stiffness of a single vibration absorption and isolation design bolt set is calculated according to the total connection stiffness calculated in step 6); 7-3) The stiffness of the vibration absorption unit of the vibration absorption and isolation design bolt set is set as the connection stiffness of the vibration absorption unit; 7-4) The stiffness of the vibration isolation unit of the vibration absorption and isolation design bolt set is set as the connection stiffness of a single vibration absorption and isolation design bolt set.

8. The vibration absorbing and isolating design bolt set obtained by the vibration absorbing and isolating design method of claim 1, characterized in that, It comprises an elastic layer (1), a resonant mass unit (2), a mounting limiting base (3), an elastic damping pad (4), and a mounting bolt (5). The head of the mounting bolt (5) is wrapped by an elastic layer (1), the elastic layer (1) is wrapped by a resonant mass unit (2), the lower end of the elastic layer (1) is connected with the mounting limiting base (3), and a through hole is arranged on the elastic damping pad (4) to enable the tail of the mounting bolt (5) to pass through the through hole and pass through the elastic damping pad (4) to be connected with the threaded mounting hole arranged on the controller housing and the mounting box body.

9. The vibration absorbing and isolating design bolt set obtained by the vibration absorbing and isolating design method of claim 8, characterized in that, It also relates to a use method of the vibration absorption and isolation design bolt set, which specifically comprises: S1) Threaded mounting holes are arranged on the controller housing and the mounting box body, respectively; S2) Place the elastic damping pad (4) between the controller housing and the mounting box body, and align the through hole of the elastic damping pad (4) with the threaded mounting hole of the controller housing and the threaded mounting hole of the mounting box body; S3) Make the mounting bolt (5) pass through the threaded mounting hole of the controller housing, the through hole of the elastic damping pad (4) and the threaded mounting hole of the mounting box body in sequence, and tighten the mounting bolt (5) until the mounting limiting base (3) is in close contact with the controller housing.

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