Vehicle electric drive system suspension installation point rack vibration target calculation method

Abstract

The invention discloses a method for calculating a vibration target of a rack at a suspension mounting point of an electric driving system for a vehicle. The method comprises the following steps of: 1) acquiring test data of the electric driving system in a whole vehicle state; 2) analyzing an auto-power spectrum and a cross-power spectrum of test data; 3) calculating a path point-response point transfer function of the suspension mounting point based on singular value decomposition; 4) analyzing a test data spectrum; 5) calculating the contribution ratio of the path points of the suspension mounting points; and 6) calculating a rack vibration target of the suspension mounting point. The invention discloses a method for defining a vibration acceleration target of a rack suspension mounting point based on an in-vehicle noise target of a real vehicle. The one-time noise acceptance success of getting on can be realized by achieving the vibration target of the electric drive assembly rack in the early stage, so that the project development period is greatly shortened, and the project development cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicle electric drive technology, and in particular to a method for calculating a vibration target of a suspension mounting point stand of a vehicle electric drive system. Background Art

[0002] The electric drive system of new energy vehicles is the core part of the vehicle, which includes the drive motor, controller and reduction gearbox, which are usually called the "big three electrics". The function of the electric drive system is to convert electrical energy into mechanical energy to drive the vehicle. Its performance directly affects the vehicle's power, economy and the user's driving experience.

[0003] The development trend of electric drive systems for new energy vehicles is towards higher efficiency, greater integration, and greater intelligence. With the advancement of technology and the reduction of costs, it is expected that the electric drive systems of new energy vehicles will become more advanced in the future, providing consumers with a better driving experience.

[0004] As competition in the new energy vehicle market becomes increasingly fierce, the research and development cycle of its core component, the electric drive system, is getting shorter and shorter, and the speed of product iteration is getting faster and faster. However, a large number of tests on the electric drive system before installation require bench testing instead of the whole vehicle.

[0005] Since there is a large gap between the boundaries of the electric drive system on the test bench and the boundaries installed on the whole vehicle, there is often a big difference between the test performance on the test bench and the performance on the whole vehicle. Therefore, how to set the vibration acceleration target of the suspension mounting point of the electric drive system on the test bench based on the early in-vehicle noise target of the product is the most critical link in establishing the bench test development of the electric drive system and the vibration and noise performance of the whole vehicle, and it is also a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a method for calculating the bench vibration target of the suspension mounting point of the electric drive system based on the early in-vehicle noise target of the product, so as to achieve a one-time successful noise acceptance on the vehicle by achieving the early electric drive assembly bench vibration target, greatly shorten the project development cycle, and reduce the project development cost.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for calculating vibration targets of a suspension mounting point stand of a vehicle electric drive system comprises the following steps:

[0009] Step 1) collecting test data of the electric drive system in the whole vehicle state;

[0010] Step 2) Auto-power spectrum and cross-power spectrum analysis of test data;

[0011] Step 3) calculating the path point-response point transfer function of the suspension installation point based on singular value decomposition;

[0012] Step 4) spectral analysis of test data;

[0013] Step 5) Calculate the contribution ratio of the path points of the suspension installation point;

[0014] Step 6) Calculate the vibration target of the rig at the suspension installation point.

[0015] Preferably, in step 1), a sound collection device is arranged in the vehicle, and a vibration acceleration sensor is arranged at the suspension mounting point where the electric drive system and the vehicle body are connected. The sound collection device is used to collect noise signals during the vehicle testing process, and the vibration acceleration sensor is used to collect vibration acceleration signals during the vehicle testing process. The entire vehicle testing process includes at least one complete acceleration process of the vehicle and at least one complete deceleration process of the vehicle.

[0016] Preferably, step 2) comprises the following steps:

[0017] Step 2.1) Calculate the auto-power spectrum of the collected noise signal and vibration acceleration signal, and the calculation formula is:

[0018]

[0019] Where: ω is the frequency; X d (ω) is the frequency domain calculation result of the vibration acceleration signal at the suspension installation point; Y(ω) is the frequency domain calculation result of the noise signal; x dn is the time domain data of the vibration acceleration signal of the dth suspension installation point at time n; n is the noise signal time domain data of the sound collection device at time n; X * d (ω) is the frequency domain conjugate result of the vibration acceleration signal at the suspension installation point; Y * (ω) is the frequency domain conjugate result of the noise signal; S xxd (ω) is the auto-power spectrum result of the vibration acceleration signal of the dth suspension installation point; S yy (ω) is the auto-power spectrum result of the noise signal;

[0020] Step 2.2) Calculate the cross power spectrum of the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points, and the calculation formula is:

[0021]

[0022] Where: Sxdy (ω) is the cross power spectrum of the acoustic signal and the vibration acceleration signal at the dth suspension installation point.

[0023] Preferably, step 3) includes the following steps:

[0024] Step 3.1) Calculate the initial transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points. The calculation formula is:

[0025]

[0026] Where: G xdy (ω) is the transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at the dth suspension installation point;

[0027] Step 3.2) Perform singular value decomposition on the initial transfer function calculated in step 3.1), and the decomposition calculation formula is:

[0028]

[0029] Where: U is the direction matrix; V is the projection of the initial transfer function on the direction matrix after decoupling; σ1, σ2, …σ m are the decomposed singular values;

[0030] Step 3.3) After removing the singular values ​​caused by the interference noise, the transfer function after singular value decomposition is calculated according to the following formula:

[0031]

[0032] Where: G^ xdy (ω) is the transfer function after singular value decomposition, σ s is the last singular value that satisfies greater than 0.01σ1.

[0033] Preferably, in step 4), the first direction of the first suspension installation point is selected as the phase reference, and the spectrum analysis is performed according to the following formula;

[0034]

[0035] Where: X ds (ω) is the spectrum analysis result of the vibration acceleration signal at the suspension installation point; is the phase difference between the vibration acceleration signal of the dth suspension installation point and the vibration acceleration signal of the first suspension installation point.

[0036] Preferably, step 5) includes the following steps:

[0037] Step 5.1) Calculate the in-vehicle noise value caused by each suspension installation point in each frequency band according to the following formula;

[0038] z d (ω) = X ds (ω)G xdy (ω)

[0039] Where: zd(ω) is the interior noise value caused by the dth suspension installation point;

[0040] Step 5.2) Sum the vehicle interior noise values ​​caused by each suspension installation point calculated in step 5.1) to obtain the composite noise value transmitted to the vehicle interior by the noise of all suspension installation points. The calculation formula is:

[0041]

[0042] Where: Z(ω) is the composite noise value transmitted to the vehicle from all mounting points;

[0043] Step 5.3) Use the interior noise value z caused by each suspension installation point d By comparing the composite noise value Z(ω) transmitted to the vehicle from all the mounting points with the noise from all the mounting points, the contribution ratio of each mounting point can be calculated.

[0044] Preferably, step 6) includes the following steps:

[0045] Step 6.1) Calculate the individual noise target for each suspension mounting point according to the following formula:

[0046]

[0047] Where: C d (ω) is the contribution ratio of the dth suspension installation point; p d (ω) is the individual noise target of the d-th mounting point in decibels; P(ω) is the individual noise target of the d-th mounting point in Pascals;

[0048] Step 6.2) Calculate the vibration target of each suspension installation point according to the following formula:

[0049]

[0050] Where: E d (ω) is the vibration target of the dth suspension installation point.

[0051] Preferably, in step 1), the sound collection device is a microphone, and the microphone is arranged at the right ear of the driver in the vehicle. During the vehicle test, the sampling frequencies of the microphone and the vibration acceleration sensor are both set to 25600 Hz.

[0052] Compared with the prior art, the present invention has the following advantages:

[0053] 1. The method of the present invention for calculating the contribution of vibration of each suspension installation point to the vehicle interior noise during the actual driving process of the vehicle can realize the rapid location of the noise problem inside the vehicle.

[0054] 2. The present invention calculates the transfer function of the suspension installation point-in-vehicle response point based on singular value decomposition; the transfer function directly reflects the structural stiffness of the vehicle body and chassis, and realizes a rapid evaluation of the vehicle structural stiffness.

[0055] 3. The present invention provides a method for defining the vibration acceleration target of the test bench suspension installation point based on the actual vehicle interior noise target; by achieving the early electric drive assembly test bench vibration target, a one-time noise acceptance test can be successfully completed, thereby greatly shortening the project development cycle and reducing project development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A diagram of the driving motor speed during the acceleration and deceleration process in the vibration target calculation method for the suspension installation point stand of the vehicle electric drive system of the present invention;

[0057] Figure 2 It is a vibration acceleration signal diagram at the suspension installation point in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0058] Figure 3 It is a noise signal diagram in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0059] Figure 4 It is an autopower spectrum of the vibration acceleration signal of the suspension installation point in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0060] Figure 5 The auto-power spectrum of the noise signal in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0061] Figure 6 It is a cross-power spectrum diagram of the noise signal and the vibration acceleration signal in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0062] Figure 7 It is a transfer function diagram after singular value decomposition in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0063] Figure 8 It is a diagram of the vibration spectrum analysis result of the suspension installation point in the vibration target calculation method of the suspension installation point stand of the vehicle electric drive system of the present invention;

[0064] Fig. 9 This is a comparison diagram of the vibration target of the suspension installation point in the vibration target calculation method of the vehicle electric drive system suspension installation point bench and the actual measurement result of the bench. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0066] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] This solution provides a method for calculating the vibration target of the suspension installation point of the electric drive system for a vehicle. The electric drive system generally refers to a system that integrates key components such as the drive motor, controller, and reducer into one module. The entire electric drive system is installed on the vehicle through multiple suspension installation points. This method specifically includes the following steps:

[0068] Step 1) Collect test data of the electric drive system in the complete vehicle state.

[0069] Specifically, a sound collection device, such as a microphone, is arranged in the vehicle, and the microphone is arranged at the right ear of the driver in the vehicle. Vibration acceleration sensors are arranged at all suspension mounting points where the electric drive system and the vehicle body are connected. The sound collection device is used to collect noise signals during vehicle testing, and the vibration acceleration sensor is used to collect vibration acceleration signals during vehicle testing. During the entire test process, the relative positions of the microphone and the vibration acceleration sensor and the vehicle body cannot move at all. During the entire test process, ensure that the windows are completely closed, and the air conditioner and audio equipment cannot be turned on in the car. The sampling frequencies of the microphone and the vibration acceleration sensor are set to 25600Hz, and the entire vehicle test process includes at least one complete acceleration process and at least one complete deceleration process. During the acceleration and deceleration process of the entire test, the speed of the drive motor is as shown in the attached figure. Figure 1 As shown in the attached figure, the vibration acceleration signal Figure 2 As shown in the attached figure, the noise signal Figure 3 shown.

[0070] Step 2) Auto-power spectrum and cross-power spectrum analysis of the experimental data.

[0071] Step 2.1) Calculate the power spectrum of the collected noise signal and vibration acceleration signal, and the calculation formula is:

[0072]

[0073] Where: ω is the frequency; X d (ω) is the frequency domain calculation result of the vibration acceleration signal at the suspension installation point; Y(ω) is the frequency domain calculation result of the noise signal; x dn is the time domain data of the vibration acceleration signal of the dth suspension installation point at time n; n is the noise signal time domain data of the sound collection device at time n; X * d (ω) is the frequency domain conjugate result of the vibration acceleration signal at the suspension installation point; Y * (ω) is the frequency domain conjugate result of the noise signal; S xxd (ω) is the auto-power spectrum result of the vibration acceleration signal of the dth suspension installation point; S yy(ω) is the auto-power spectrum result of the noise signal; the interval of n is 4Hz. The auto-power spectrum result of the vibration acceleration signal of the suspension installation point is shown in the attached figure. Figure 4 The auto-power spectrum of the microphone noise signal is shown in the attached figure. Figure 5 shown.

[0074] Step 2.2) Calculate the cross power spectrum of the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points, and the calculation formula is:

[0075]

[0076] Where: S xdy (ω) is the cross power spectrum of the acoustic signal and the vibration acceleration signal at the dth suspension installation point. The calculated cross power spectrum is shown in the attached figure. Figure 6 shown.

[0077] Step 3) Calculate the path point-response point transfer function of the suspension installation point based on singular value decomposition. Since the transfer function in this scheme is not obtained through actual measurement, but is calculated through auto-power spectrum and cross-power spectrum, it is necessary to exclude the influence of interference noise, which specifically includes the following steps:

[0078] Step 3.1) Calculate the initial transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points. The calculation formula is:

[0079]

[0080] Where: G xdy (ω) is the transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at the dth suspension installation point.

[0081] Step 3.2) Perform singular value decomposition on the initial transfer function calculated in step 3.1), and the decomposition calculation formula is:

[0082]

[0083] Where: U is the direction matrix, which is used to decouple the signals between the paths; V is the projection of the initial transfer function on the direction matrix after decoupling; σ1, σ2, …σ m is the decomposed singular value; the smaller the subscript, the larger the singular value. When a singular value is less than 0.01σ1, it is considered that the singular value is caused by interference noise and needs to be eliminated.

[0084] Step 3.3) After removing the singular values ​​caused by the interference noise, the transfer function after singular value decomposition is calculated according to the following formula:

[0085]

[0086] Where: G^ xdy (ω) is the transfer function after singular value decomposition, σ s is the last singular value that satisfies a value greater than 0.01σ1. The transfer function after singular value decomposition is shown in the attached figure. Figure 7 shown.

[0087] Step 4) Spectral analysis of experimental data.

[0088] According to the frequency domain calculation results of the vibration acceleration signal and noise signal at each mounting point in the previous step, the first direction of the first mounting point is selected as the phase reference, and the spectrum analysis is performed according to the following formula;

[0089]

[0090] Where: X ds (ω) is the spectrum analysis result of the vibration acceleration signal at the suspension installation point; is the phase difference between the vibration acceleration signal of the dth suspension installation point and the vibration acceleration signal of the first suspension installation point. The vibration spectrum analysis results of the suspension installation point are shown in the attached figure. Figure 8 shown.

[0091] Step 5) Calculate the contribution ratio of the path points of the suspension installation point.

[0092] Step 5.1) Calculate the in-vehicle noise value caused by each suspension installation point in each frequency band according to the following formula;

[0093] z d (ω) = X ds (ωG xdy (ω)

[0094] Where: z d (ω) is the in-vehicle noise value caused by the dth suspension installation point;

[0095] Step 5.2) Sum the vehicle interior noise values ​​caused by each suspension installation point calculated in step 5.1) to obtain the composite noise value transmitted to the vehicle interior by the noise of all suspension installation points. The calculation formula is:

[0096]

[0097] Where: Z(ω) is the composite noise value transmitted to the vehicle from all mounting points;

[0098] Step 5.3) Use the interior noise value z caused by each suspension installation point d By comparing the composite noise value Z(ω) transmitted to the vehicle from all the mounting points with the noise from all the mounting points, the contribution ratio of each mounting point can be calculated.

[0099] The calculated contribution of each suspension installation point is shown in Table 1:

[0100] Table 1 Calculated contribution ratio of each suspension installation point

[0101]

[0102] Step 6) Calculate the vibration target of the rig at the suspension installation point.

[0103] Step 6.1) Calculate the individual noise target for each suspension mounting point according to the following formula:

[0104]

[0105] Where: C d (ω) is the contribution ratio of the dth suspension installation point; p d (ω) is the individual noise target of the d-th mounting point in decibels; P(ω) is the individual noise target of the d-th mounting point in Pascals;

[0106] The calculated results are shown in Table 2:

[0107] Table 2: Individual noise targets for each suspension mounting point

[0108]

[0109] Step 6.2) Calculate the vibration target of each suspension installation point according to the following formula:

[0110]

[0111] Where: E d (ω) is the vibration target of the dth suspension installation point.

[0112] The calculated vibration targets of each suspension installation point are shown in Figure 3:

[0113] Table 3: Vibration targets for each mounting point

[0114]

[0115] The calculated vibration targets of each suspension installation point are compared with the actual test results of the bench. Fig. 9 shown.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for calculating vibration targets of a suspension mounting point stand for an electric drive system for a vehicle, characterized in that: The following steps are involved: Step 1) collecting test data of the electric drive system in the whole vehicle state; Step 2) Auto-power spectrum and cross-power spectrum analysis of test data; Step 3) calculating the path point-response point transfer function of the suspension installation point based on singular value decomposition; Step 4) spectral analysis of test data; Step 5) Calculate the contribution ratio of the path points of the suspension installation point; Step 6) Calculate the vibration target of the rig at the suspension installation point.

2. The method for calculating vibration target of the suspension installation point of the electric drive system for a vehicle according to claim 1, characterized in that: In step 1), a sound collection device is arranged in the vehicle, and a vibration acceleration sensor is arranged at the suspension mounting point where the electric drive system and the vehicle body are connected. The sound collection device is used to collect noise signals during the vehicle test, and the vibration acceleration sensor is used to collect vibration acceleration signals during the vehicle test. The entire vehicle test process includes at least one complete acceleration process of the vehicle and at least one complete deceleration process of the vehicle.

3. The method for calculating vibration target of the suspension installation point of the electric drive system for a vehicle according to claim 2, characterized in that: Step 2) includes the following steps: Step 2.1) Calculate the auto-power spectrum of the collected noise signal and vibration acceleration signal, and the calculation formula is: Where: ω is the frequency; X d (ω) is the frequency domain calculation result of the vibration acceleration signal at the suspension installation point; Y(ω) is the frequency domain calculation result of the noise signal; x dn is the time domain data of the vibration acceleration signal of the dth suspension installation point at time n; n is the noise signal time domain data of the sound collection device at time n; X * d (ω) is the frequency domain conjugate result of the vibration acceleration signal at the suspension installation point; Y * (ω) is the frequency domain conjugate result of the noise signal; S xxd (ω) is the auto-power spectrum result of the vibration acceleration signal of the dth suspension installation point; S yy (ω) is the auto-power spectrum result of the noise signal; Step 2.2) Calculate the cross power spectrum of the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points, and the calculation formula is: Where: S xdy (ω) is the cross power spectrum of the acoustic signal and the vibration acceleration signal at the dth suspension installation point.

4. The method for calculating vibration target of the suspension installation point of the electric drive system for a vehicle according to claim 3, characterized in that: Step 3) includes the following steps: Step 3.1) Calculate the initial transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at all suspension installation points. The calculation formula is: Where: G xdy (ω) is the transfer function between the noise signal collected by the sound collection device and the vibration acceleration signal at the dth suspension installation point; Step 3.2) Perform singular value decomposition on the initial transfer function calculated in step 3.1), and the decomposition calculation formula is: Where: U is the direction matrix; V is the projection of the initial transfer function on the direction matrix after decoupling; σ1, σ2, …σ m are the decomposed singular values; Step 3.3) After removing the singular values ​​caused by the interference noise, the transfer function after singular value decomposition is calculated according to the following formula: Where: G ^ xdy (ω) is the transfer function after singular value decomposition, σ s is the last singular value that satisfies greater than 0.01σ1.

5. The method for calculating vibration target of the suspension installation point stand of the vehicle electric drive system according to claim 4, characterized in that: In step 4), the first direction of the first suspension installation point is selected as the phase reference, and the spectrum analysis is performed according to the following formula; Where: X ds (ω) is the spectrum analysis result of the vibration acceleration signal at the suspension installation point; is the phase difference between the vibration acceleration signal of the dth suspension installation point and the vibration acceleration signal of the first suspension installation point.

6. The method for calculating vibration target of the suspension installation point stand of the electric drive system for a vehicle according to claim 5, characterized in that: Step 5) includes the following steps: Step 5.1) Calculate the in-vehicle noise value caused by each suspension installation point in each frequency band according to the following formula; z d (ω)=X ds (ω)G xdy (oh) Where: zd(ω) is the interior noise value caused by the dth suspension installation point; Step 5.2) Sum the vehicle interior noise values ​​caused by each suspension installation point calculated in step 5.1) to obtain the composite noise value transmitted to the vehicle interior by the noise of all suspension installation points. The calculation formula is: Where: Z(ω) is the composite noise value transmitted to the vehicle from all mounting points; Step 5.3) Use the interior noise value z caused by each suspension installation point d By comparing the composite noise value Z(ω) transmitted to the vehicle from all the mounting points with the noise from all the mounting points, the contribution ratio of each mounting point can be calculated.

7. The method for calculating vibration target of a suspension installation point stand of a vehicle electric drive system according to claim 6, characterized in that: Step 6) includes the following steps: Step 6.1) Calculate the individual noise target for each suspension installation point according to the following formula: Where: C d (ω) is the contribution ratio of the dth suspension installation point; p d (ω) is the individual noise target of the d-th mounting point in decibels; P(ω) is the individual noise target of the d-th mounting point in Pascals; Step 6.2) Calculate the vibration target of each suspension installation point according to the following formula: Where: E d (ω) is the vibration target of the dth suspension installation point.

8. The method for calculating vibration target of a suspension installation point stand of a vehicle electric drive system according to claim 2, characterized in that: In step 1), the sound collection device is a microphone, and the microphone is placed at the right ear of the driver in the car. During the vehicle test, the sampling frequencies of the microphone and the vibration acceleration sensor are both set to 25600 Hz.

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