A method, apparatus, and computer storage medium for a suspension design

Abstract

This invention provides a design method, device, and computer storage medium for a suspension mount, belonging to the field of automotive manufacturing technology. The method includes: acquiring parameters of different powertrains; calculating the torque axis of each powertrain based on the parameters; determining the location of the suspension elastic center according to the arrangement rules of the line connecting the torque axis and the suspension elastic center; calculating the optimal stiffness value of the suspension mount with the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint, and stiffness as the variable; calculating the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value; and taking the stiffness value that simultaneously satisfies the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the suspension mount. This invention simplifies the suspension mounts of multiple different powertrains into a single suspension mount while ensuring the vibration isolation performance of the suspension system.

Description

Technical Field

[0001] This invention belongs to the field of automotive manufacturing technology, specifically relating to a suspension design method, device, suspension, and computer storage medium. Background Technology

[0002] Currently, vehicle development often adopts a platform-based approach. To meet different positioning needs, different configurations on the same platform often use different powertrains, meaning that a single platform can contain several different powertrain configurations. Different powertrains have different inertial parameters, and these parameters typically require different mount positions, resulting in several different mount locations on the same platform, which is detrimental to the commonality of body design. Different inertial parameters also lead to different mount stiffness parameters, resulting in multiple sets of different mounts, similarly hindering the commonality of mount system design. Simply using the same mount position and the same rubber stiffness parameters, however, will degrade the performance of the mount system and is detrimental to overall vehicle vibration isolation. Summary of the Invention

[0003] The purpose of this invention is to solve the problems existing in the prior art and provide a method, device, suspension and computer storage medium for the architectural design of suspension, which simplifies the suspension of multiple different powertrains into a single suspension while ensuring the vibration isolation performance of the suspension system.

[0004] This invention is achieved through the following technical solution:

[0005] A first aspect of the present invention provides a suspension design method, comprising the following steps:

[0006] Obtain parameters for different powertrains;

[0007] The torque axis of each powertrain is calculated based on the parameters of the different powertrains, and the position of the suspension elastic center is determined according to the arrangement rules of the line connecting the torque axis and the suspension elastic center.

[0008] The optimal stiffness value of the suspension is calculated with the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint, and the stiffness as the variable.

[0009] The natural frequency and decoupling rate of each powertrain are calculated based on the optimal stiffness value, and the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement is taken as the target stiffness value of the suspension.

[0010] A further improvement of the present invention is that:

[0011] The parameters of the powertrain include the moment of inertia of the powertrain and the coordinates of the center of mass of the powertrain, and different powertrains have different parameters;

[0012] The powertrain may include an engine, a transmission, or other components integrated into the transmission, such as a clutch / front differential, but any powertrain can be used in the method of the present invention.

[0013] A further improvement of the present invention is that:

[0014] The specific operation of calculating the torque shaft of each powertrain based on the parameters of different powertrains includes:

[0015] An inertia matrix is ​​established based on the rotational inertia of the powertrain. The eigenvalues ​​of the inertia matrix are the principal moments of inertia of the powertrain relative to its center of mass, and the corresponding eigenvectors are the torque axes of the powertrain. The inertia matrix is ​​as follows:

[0016]

[0017] Among them, J xx J is the moment of inertia about the X-axis; yy J is the moment of inertia about the Y-axis; zz J is the moment of inertia about the Y-axis; xy J is the product of inertia about the XY axis; xz J is the product of inertia about the XZ axis; yz It is the product of inertia about the YZ axis.

[0018] A further improvement of the present invention is that:

[0019] The determination of the suspension elastic center's location based on the arrangement rule of the line connecting the torque axis and the suspension elastic center is specifically as follows:

[0020] The suspension arrangement is a TRA three-point suspension arrangement system, and the arrangement rules include:

[0021] (1) The angle between the line connecting the centers of the left and right suspension elasticity and the torque axis is less than 5 degrees;

[0022] (2) The distance between the center of mass and the line connecting the left and right suspension elastic centers is less than 5mm.

[0023] The location of the flexible center that meets this condition is a range. Within this range, the point that minimizes both the included angle and the distance between the connecting lines is the target location.

[0024] Theoretically, when the line connecting the elastic centers of the left and right suspensions coincides perfectly with the torque axis, the vibrations in all six directions of the suspension system can be completely decoupled. However, due to layout limitations, it is generally required that the angle between the line connecting the elastic centers and the torque axis be as small as possible, and the distance between the center of mass and the elastic center be as small as possible. Based on previous layout and performance data, the angle is defined as less than 5 degrees, and the distance between the connecting lines is less than 5 mm as a reasonable target. This layout requirement can ensure the decoupling performance of the suspension system.

[0025] A further improvement of the present invention is that:

[0026] The process of calculating the optimal stiffness value of the suspension, with the powertrain decoupling rate as the optimization objective, natural frequency as the constraint, and stiffness as the variable, includes the following steps:

[0027] The optimization objective is to optimize the powertrain decoupling rate. The target values ​​for the decoupling rates in the main Z-direction (bounce) and Y-direction (pitch) are Max f1(x) and Max f2(x) respectively, which are greater than a first preset value. The target values ​​for the decoupling rates in other directions are greater than a second preset value. The objective function is:

[0028] Max f1(x)=f1(Left_x,Left_y,Left_z,Right_x,Right_y,Right_z,Rear_x)

[0029] Max f2(x)=f2(Left_x,Left_y,Left_z,Right_x,Right_y,Right_z,Rear_x)

[0030] The natural frequency is a constraint condition, where:

[0031] Fre_x_min≤Fore / Aft(X)≤Fre_x_max;

[0032] Fre_y_min≤Lateral(Y)≤Fre_y_max;

[0033] Fre_z_min≤Bounce(Z)≤Fre_z_max;

[0034] Fre_Rx_min≤Roll(around X)≤Fre_Rx_max;

[0035] Fre_Ry_min≤Pitch(around Y)≤Fre_Ry_max;

[0036] Fre_Rz_min≤Yaw(around Z)≤Fre_Rz_max;

[0037] Where Fre_x_min, Fre_x_max, Fre_y_min, Fre_y_max, Fre_z_min, Fre_z_max, Fre_Rx_min, Fre_Rx_max, Fre_Ry_min, Fre_Ry_max, Fre_Rz_min, and Fre_Rz_max are the inherent frequency ranges. Preferably, 6.7≤Fore / Aft(X)≤9, 5≤Lateral(Y)≤7.5, 7.5≤Bounce(Z)≤9, 14≤Roll(around X)≤16, 8≤Pitch(around Y)≤11, and 12≤Yaw(around Z)≤16.

[0038] The stiffness of the left suspension in three directions (Left_x, Left_y, Left_z), the right suspension in three directions (Right_x, Right_y, Right_z), and the rear suspension in the x-direction (Rear_x) are variables. The stiffness of the rear suspension in the y and z directions is taken as the equivalent stiffness, which is 10 N / mm.

[0039] The variables are designed as follows:

[0040] Left_x_min≤Left_x≤Left_x_max

[0041] Left_y_min≤Left_y≤Left_y_max

[0042] Left_z_min≤Left_z≤Left_z_max

[0043] Right_x_min≤Right_x≤Right_x_max

[0044] Right_y_min≤Right_y≤Right_y_max

[0045] Right_z_min≤Right_z≤Right_z_max

[0046] Rear_x_min≤Rear_x≤Rear_x_max;

[0047] Among them, Left_x_min, Left_x_max, Left_y_min, Left_y_max, Left_z_min, Left_z_max, Right_x_min, Right_x_max, Right_y_min, Right_y_max, Right_z_min, Right_z_max, Rear_x_min, and Rear_x_max are stiffness ranges, calculated using CAE (Computer Aided Engineering).

[0048] After setting the optimization objective, constraints, and optimization variables, the optimal stiffness value for each powertrain component is obtained.

[0049] A further improvement of the present invention is that:

[0050] The specific steps for calculating the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value include:

[0051] The natural frequency and decoupling rate of each powertrain were calculated using the optimal stiffness values ​​corresponding to each powertrain assembly, as follows:

[0052] The natural frequency is obtained using formula (1):

[0053]

[0054] Where M is the system mass matrix, K is the system stiffness matrix, and ω is the frequency matrix. The mode shape matrix;

[0055] The system decoupling rate is obtained using formula (2):

[0056]

[0057] Where, m kl φ is the element in the k-th row and l-th column of M. i For the i-th order main array of the system, T k For the energy of the Kth degree of freedom, T i Let be the total energy of the i-th natural frequency.

[0058] A further improvement of the present invention is that:

[0059] The conditions for simultaneously satisfying the stiffness values ​​of the preset natural frequency requirement and the preset decoupling rate requirement include: the decoupling rate satisfies the first preset condition, and the natural frequency satisfies the second preset condition;

[0060] The first preset condition is: the decoupling rate target value in the main direction Z (Bounce) and around the Y direction (Pitch) is greater than 90%, and the decoupling rate target value in other directions is greater than 80%.

[0061] The second preset conditions are: 6.7≤Fore / Aft(X)≤9, 5≤Lateral(Y)≤7.5, 7.5≤Bounce(Z)≤9, 14≤Roll(around X)≤16, 8≤Pitch(around Y)≤11, 12≤Yaw(around Z)≤16.

[0062] A second aspect of the present invention provides a suspension design device, comprising:

[0063] Acquisition unit, used to acquire parameters of different powertrains;

[0064] The arrangement position determination unit is used to calculate the torque shaft of each powertrain based on the parameters of different powertrains, and determine the arrangement position of the suspension elastic center according to the arrangement rule of the line connecting the torque shaft and the suspension elastic center.

[0065] The optimal stiffness value determination unit is used to calculate and obtain the optimal stiffness value of the suspension with the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint condition, and stiffness as the variable.

[0066] The target stiffness value determination unit calculates the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value, and takes the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the suspension.

[0067] A third aspect of the invention provides a suspension using the suspension design method described above.

[0068] A fourth aspect of the present invention provides a computer-readable storage medium storing at least one computer-executable program, which, when executed by the computer, causes the computer to perform the steps in the suspension design method described above.

[0069] Compared with the prior art, the beneficial effects of the present invention are:

[0070] This invention simplifies the joint optimization design of multiple different powertrain mounts into a single mount system. It uses the stiffness value that simultaneously meets the preset natural frequency requirements and preset decoupling rate requirements as the target stiffness value of the mount, overcoming the problem of multiple different mounts in the same platform vehicle in the prior art. It realizes the platform design of the mount system, while ensuring the performance optimization of each powertrain mount system and the vibration isolation performance of the mount system. Attached Figure Description

[0071] Figure 1This is a flowchart of a suspended architectural design method according to the present invention;

[0072] Figure 2 This is a diagram showing the arrangement of the suspension TRA and the elastic center. Detailed Implementation

[0073] The present invention will now be described in further detail with reference to the accompanying drawings:

[0074] This invention provides a suspension design method, and an embodiment of the method is as follows:

[0075]

Example 1

[0076] like Figure 1 As shown, the method includes the following steps:

[0077] S1. Obtain parameters for different powertrains;

[0078] The parameters of the powertrain include the mass of the powertrain, the moment of inertia of the powertrain, and the coordinates of the center of mass of the powertrain, with different parameters for different powertrains.

[0079] The powertrain may include an engine, a transmission, or other components integrated into the transmission, such as a clutch / front differential, but any powertrain can be used in the method of the present invention.

[0080] The parameters of the powertrain can be obtained through methods such as the three-line pendulum measurement method and digital model measurement.

[0081] Among them, the three-wire pendulum measurement method and the digital model measurement method are existing conventional methods, and will not be elaborated here.

[0082] S2. Calculate the torque shaft of each powertrain based on the parameters of different powertrains, and preliminarily determine the location of the suspension elastic center based on the arrangement rules of the line connecting the torque shaft and the suspension elastic center.

[0083] Calculate the torque shafts of each powertrain component based on the powertrain parameters. The specific steps include:

[0084] The inertia matrix is ​​established based on the moment of inertia, and the principal inertia matrix is ​​obtained from the inertia matrix, thereby calculating the torque axis;

[0085] The inertia matrix J is:

[0086]

[0087] Among them, J xx J is the moment of inertia about the X-axis; yy J is the moment of inertia about the Y-axis; zz J is the moment of inertia about the Y-axis; xyJ is the product of inertia about the XY axis; xz J is the product of inertia about the XZ axis; yz The product of inertia about the YZ axis;

[0088] J'=(c 12 ) T .JC 12

[0089] J is the inertia matrix, J' is the principal axis of inertia matrix, and C... 12 Let be the cosine matrix of the principal axis coordinate system in the original coordinate system;

[0090]

[0091]

[0092]

[0093]

[0094] α”, β”, γ” are the azimuth angles of the torque axis in the global coordinate system, respectively; α i ',β i ',γ i ' represents the azimuth angle of the i-th principal axis of inertia in the global coordinate system; J i The moment of inertia of the principal axis of inertia;

[0095] The powertrain torque axis can be obtained through the above calculations, which can be used as the basis for arranging the suspension elastic center.

[0096] The initial location of the suspension elastic center is determined based on the arrangement rules of the line connecting the torque shaft and the suspension elastic center, specifically including:

[0097] The suspension arrangement is a TRA three-point suspension arrangement system, and the arrangement rules include:

[0098] (1) The angle between the line connecting the centers of the left and right suspension elasticity and the torque axis is less than 5 degrees;

[0099] (2) The distance between the center of mass and the line connecting the left and right suspension elastic centers is less than 5mm.

[0100] It should be noted that the location of the flexible center that meets this condition is a range. Within this range, the point that minimizes both the included angle and the distance between the connecting lines is the target location.

[0101] Theoretically, when the line connecting the elastic centers of the left and right suspensions coincides perfectly with the torque axis, the vibrations in all six directions of the suspension system can be completely decoupled. However, due to layout limitations, it is generally required that the angle between the line connecting the elastic centers and the torque axis be as small as possible, and the distance between the center of mass and the elastic center be as small as possible. Based on previous layout and performance data, the angle is defined as less than 5 degrees, and the distance between the connecting lines is less than 5 mm as a reasonable target. This layout requirement can ensure the decoupling performance of the suspension system.

[0102] S3. Determine the rubber structure of each suspension according to the vehicle model and space, and calculate the stiffness range and stiffness ratio of each suspension through CAE analysis.

[0103] The specific steps involve determining the rubber structure of each suspension mount based on the vehicle model and available space, including:

[0104] If, after benchmarking, the vehicle model is defined as a low-to-medium performance vehicle, the right suspension can be set to a hydraulic suspension, and the left and rear suspensions to pure rubber suspensions; if the vehicle model is defined as a medium-to-high performance vehicle, the right and left suspensions can be set to hydraulic suspensions, and the rear suspension to rubber suspensions.

[0105] Depending on the vehicle's layout space, the left and right suspensions can be either trapezoidal or cylindrical. If the Y-direction space is small, a trapezoidal suspension can be chosen, while if the Y-direction space is large, a cylindrical suspension can be chosen. Typically, one side uses a trapezoidal suspension and the other side uses a cylindrical suspension.

[0106] The stiffness range and stiffness ratio in each direction of each suspension are calculated using CAE analysis. Specific operations include:

[0107] The rubber was meshed into tetrahedrals using general meshing tools such as HYPERMESH, and its stiffness was solved using general software such as ABAQUS, thereby obtaining the stiffness range of each suspension and the stiffness ratio in each direction.

[0108] S4. Calculate the optimal stiffness value of the suspension with the powertrain decoupling rate as the optimization objective, natural frequency as the constraint condition, and stiffness as the variable.

[0109] Under the constraint conditions, the stiffness value at which the decoupling rate reaches its maximum is the optimal stiffness value.

[0110] The specific operations include:

[0111] With the powertrain decoupling rate as the optimization objective, the target decoupling rates in the main Z-direction (bounce) and Y-direction (pitch) are both greater than 90% (Max f1(x) and Max f2(x) respectively), and the target decoupling rates in other directions are greater than 80%. The objective function is:

[0112] Max f1(x)=f1(Left_x,Left_y,Left_z,Right_x,Right_y,Right_z,Rear_x)

[0113] Max f2(x)=f2(Left_x,Left_y,Left_z,Right_x,Right_y,Right_z,Rear_x)

[0114] The natural frequency is a constraint condition, where:

[0115] Fre_x_min≤Fore / Aft(X)≤Fre_x_max;

[0116] Fre_y_min≤Lateral(Y)≤Fre_y_max;

[0117] Fre_z_min≤Bounce(Z)≤Fre_z_max;

[0118] Fre_Rx_min≤Roll(around X)≤Fre_Rx_max;

[0119] Fre_Ry_min≤Pitch(around Y)≤Fre_Ry_max;

[0120] Fre_Rz_min≤Yaw(around Z)≤Fre_Rz_max;

[0121] Wherein, Fre_x_min, Fre_x_max, Fre_y_min, Fre_y_max, Fre_z_min, Fre_z_max, Fre_Rx_min, Fre_Rx_max, Fre_Ry_min, Fre_Ry_max, Fre_Rz_min, and Fre_Rz_max are the inherent frequency ranges, preferably 6.7≤Fore / Aft(X)≤9, 5≤Lateral(Y)≤7.5, 7.5≤Bounce(Z)≤9, 14≤Roll(around X)≤16, 8≤Pitch(around Y)≤11, and 12≤Yaw(around Z)≤16;

[0122] The stiffness of the left suspension in three directions (Left_x, Left_y, Left_z), the right suspension in three directions (Right_x, Right_y, Right_z), and the rear suspension in the x-direction (Rear_x) are variables. The stiffness of the rear suspension in the y-direction and z-direction is taken as the equivalent stiffness, which is 10 N / mm.

[0123] The variables are designed as follows:

[0124] Left_x_min≤Left_x≤Left_x_max

[0125] Left_y_min≤Left_y≤Left_y_max

[0126] Left_z_min≤Left_z≤Left_z_max

[0127] Right_x_min≤Right_x≤Right_x_max

[0128] Right_y_min≤Right_y≤Right_y_max

[0129] Right_z_min≤Right_z≤Right_z_max

[0130] Rear_x_min≤Rear_x≤Rear_x_max;

[0131] Where Left_x_min, Left_x_max, Left_y_min, Left_y_max, Left_z_min, Left_z_max, Right_x_min, Right_x_max, Right_y_min, Right_y_max, Right_z_min, Right_z_max, Rear_x_min, and Rear_x_max are stiffness ranges, calculated using CAE.

[0132] After setting the optimization objective, constraints, and optimization variables, the optimal stiffness values ​​1, 2, 3, etc., corresponding to each powertrain A, B, C, etc., can be obtained using the ISIGHT and MATLAB joint optimization method.

[0133] S5. Calculate the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value, and take the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the suspension.

[0134] Using the optimal stiffness values ​​1, 2, 3... obtained in step S4, or with appropriate adjustments based on these stiffness values, verify the natural frequencies and decoupling rates of powertrains A, B, C... respectively. Specifically:

[0135] The principal mode equations of the system are as follows, and the natural frequencies are obtained through formula (1):

[0136]

[0137] Where M is the system mass matrix, K is the system stiffness matrix, and ω is the frequency matrix. The mode shape matrix;

[0138] The system decoupling rate is obtained using formula (2):

[0139]

[0140] Where, m kl φ is the element in the k-th row and l-th column of M. i For the i-th order main array of the system, T k For the energy of the Kth degree of freedom, T i Let be the total energy of the i-th natural frequency.

[0141] Find a set of stiffness values ​​that can simultaneously satisfy the natural frequency and decoupling rate of each powertrain. If a set of stiffness values ​​that can simultaneously satisfy the natural frequency and decoupling rate of each powertrain can be found, the system design can be completed by selecting this set of stiffness values. If no such set of stiffness values ​​can be found, return to step S3 and re-execute steps S3 to S5 by changing the rubber structure design to different stiffness structures until a set of stiffness values ​​that can satisfy the natural frequency and decoupling rate of each powertrain is found. If there are multiple sets of stiffness values ​​that meet the requirements, one of them can be selected.

[0142] The conditions for simultaneously satisfying the stiffness values ​​of the preset natural frequency requirement and the preset decoupling rate requirement include: the decoupling rate satisfies the first preset condition, and the natural frequency satisfies the second preset condition;

[0143] The first preset condition is: the decoupling rate target value in the main direction Z (Bounce) and around the Y direction (Pitch) is greater than 90%, and the decoupling rate target value in other directions is greater than 80%.

[0144] The second preset conditions are: 6.7≤Fore / Aft(X)≤9, 5≤Lateral(Y)≤7.5, 7.5≤Bounce(Z)≤9, 14≤Roll(around X)≤16, 8≤Pitch(around Y)≤11, 12≤Yaw(around Z)≤16.

[0145] This invention simplifies the joint optimization design of multiple different powertrain mounts into a single mount system. It uses the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the mount. This overcomes the problem of multiple different mounts in a unified platform vehicle model in the prior art, realizes the platform design of the mount system, and at the same time ensures the performance optimization of each powertrain mount system and the vibration isolation performance of the mount system.

[0146] Examples of applying the method of the present invention are as follows:

[0147]

Example 2

[0148] This embodiment includes three powertrains: A, B, and C. The mass parameters of the three powertrains were measured using a three-line pendulum physical measurement method, as shown in Tables 1 and 2.

[0149] Table 1 Powertrain Mass and Moment of Inertia

[0150]

[0151] Table 2. Center of mass coordinates of the powertrain

[0152] Powertrain Xce Yce Zce A 675 -36 499 B 674 -28 504 C 679 -34 503

[0153] Based on the moments of inertia of the three powertrains A, B, and C, the eigenvectors of the inertia matrix are solved to obtain the torque axes of the three powertrains. Projecting the torque axes onto the XOY plane of the vehicle coordinate system allows us to construct the centers of mass and torque axes corresponding to the three powertrains A, B, and C. According to the suspension system layout rules: (1) the angle between the line connecting the left and right suspension elastic centers and the torque axis is less than 5 degrees; (2) the distance between the left and right suspension elastic centers is less than 5 mm. Based on the above rules and the following... Figure 2 The coordinates of the elastic center in the left suspension XOY plane can be selected as: X: 733.5, Y: -489.6; the coordinates of the elastic center in the right suspension XOY plane are: X: 606.5, Y: 501.7. Connecting these two points yields... Figure 2 The elastic center line shown is used to measure the angles between the elastic center line and the torque axes of the three powertrains A, B, and C. The angles are 1.4 degrees, 0.7 degrees, and 0.2 degrees, respectively, and all angles meet the requirements. The distances between the elastic center line and the torque axes of the three powertrains A, B, and C are 3.5 mm, 2.8 mm, and 4.2 mm, respectively. All distances are less than 5 mm, which meets the distance requirements.

[0154] Based on the vehicle model, the suspension system is selected as a 3-point TRA arrangement. The right suspension is a trapezoidal suspension, and its stiffness ratio in each direction calculated by CAE is Kx:Kz = 0.77, Ky:Kz = 0.41, with a Z-direction stiffness range of 180 N / mm to 250 N / mm. The left suspension is a tower-type suspension, and its stiffness ratio in each direction calculated by CAE is Kx:Kz = 0.65, Ky:Kz = 0.65, with a Z-direction stiffness range of 190 N / mm to 260 N / mm. The rear suspension has an equivalent stiffness of 10 N / mm in the Y and Z directions and a stiffness range of 220 to 350 N / mm in the X direction.

[0155] With the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint, and the stiffness of each suspension as the variable, the optimal stiffness values ​​for each powertrain A, B, and C were obtained using the ISIGHT and MATLAB joint optimization method, as shown in Table 3.

[0156] Table 3 Stiffness optimization results

[0157]

[0158] Table 4 Natural Frequency and Decoupling Rate of Powertrain A

[0159] Fore / Aft Lateral Bounce Roll Pitch Yaw Inherent frequency requirement range (Hz) 6.7～9 5～7.5 7.5～9 14～16 8～11 12～16 Calculated natural frequency (Hz) 8.2 5.6 8.5 14.4 9.5 12 Decoupling rate requirement (%) >80 >80 >90 >80 >90 >80 Decoupling rate calculation (%) 80.5 85 93 90 95 86

[0160] Table 5 Natural Frequency and Decoupling Rate of Powertrain B

[0161] Fore / Aft Lateral Bounce Roll Pitch Yaw Inherent frequency requirement range (Hz) 6.7～9 5～7.5 7.5～9 14～16 8～11 12～16 Calculated natural frequency (Hz) 8.5 5.4 8.1 15.4 9.6 12.1 Decoupling rate requirement (%) >80 >80 >90 >80 >90 >80 Decoupling rate calculation (%) 80.8 88 97 89 92 88

[0162] Table 6. Natural Frequency and Decoupling Rate of Powertrain C

[0163] Fore / Aft Lateral Bounce Roll Pitch Yaw Inherent frequency requirement range (Hz) 6.7～9 5～7.5 7.5～9 14～16 8～11 12～16 Calculated natural frequency (Hz) 8.7 5.8 8.9 15.6 9.9 12.8 Decoupling rate requirement (%) >80 >80 >90 >80 >90 >80 Decoupling rate calculation (%) 82.8 86 98 86 95 92

[0164] The natural frequencies and decoupling rates of the three powertrains A, B, and C were verified using the three sets of stiffness values ​​shown in Table 3. The first and third sets of stiffness values ​​could not simultaneously meet the requirements for the natural frequencies and decoupling rates of all three powertrains. The second set of stiffness values, however, could simultaneously meet these requirements. The results are shown in Tables 4-6. Table 4-6 presents the results of verifying the natural frequencies and decoupling rates of the three powertrains A, B, and C using the second set of stiffness values. Therefore, the second set of stiffness values ​​was selected as the final design stiffness values.

[0165] The present invention also provides a suspension design device, an embodiment of which is as follows:

[0166]

Example 3

[0167] The system includes:

[0168] Acquisition unit, used to acquire parameters of different powertrains;

[0169] The arrangement position determination unit is used to calculate the torque shaft of each powertrain based on the parameters of different powertrains, and determine the arrangement position of the suspension elastic center according to the arrangement rule of the line connecting the torque shaft and the suspension elastic center.

[0170] The optimal stiffness value determination unit is used to calculate and obtain the optimal stiffness value of the suspension with the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint condition, and stiffness as the variable.

[0171] The target stiffness value determination unit calculates the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value, and takes the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the suspension.

[0172] The present invention also provides a suspension device, an embodiment of which is as follows:

[0173]

Example 4

[0174] The suspension uses the suspension design method as described in Example 1.

[0175] The present invention also provides a computer storage medium, wherein embodiments of the computer storage medium are as follows:

[0176]

Example 5

[0177] The computer storage medium stores at least one computer-executable program, which, when executed by the computer, causes the computer to perform the steps in the suspension design method as described in Embodiment 1.

[0178] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A suspension design method, characterized in that, Includes the following steps: Obtain parameters for different powertrains; The torque axis of each powertrain is calculated based on the parameters of the different powertrains. The location of the suspension elastic center is determined according to the arrangement rules of the line connecting the torque axis and the suspension elastic center. Specifically, the suspension arrangement is a TRA three-point suspension arrangement system, and the arrangement rules include: (1) The angle between the line connecting the left and right suspension elastic centers and the torque axis is less than 5 degrees; (2) The distance between the center of mass and the line connecting the left and right suspension elastic centers is less than 5 mm; The optimal stiffness value of the suspension is calculated using the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint, and stiffness as the variable. Specifically, this includes: The powertrain decoupling rate is the optimization objective. The target values ​​for the decoupling rates in the main Z direction and around the Y direction, Max f1(x) and Max f2(x), are greater than the first preset value, while the target values ​​for the decoupling rates in other directions are greater than the second preset value. The stiffness of the left suspension in three directions (Left_x, Left_y, Left_z), the right suspension in three directions (Right_x, Right_y, Right_z), and the rear suspension in the x-direction (Rear_x) are variables. The stiffness of the rear suspension in the y and z directions is taken as the equivalent stiffness, which is 10 N / mm. The natural frequency and decoupling rate of each powertrain are calculated based on the optimal stiffness value, and the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement is taken as the target stiffness value of the suspension. The preset inherent frequency requirement and preset decoupling rate requirement include: The decoupling rate meets the first preset condition: the target decoupling rate in the main direction Z and around the Y direction is greater than 90%, and the target decoupling rate in other directions is greater than 80%. The inherent frequency satisfies the second preset condition: 6.7≤Fore / Aft≤9, 5≤Lateral≤7.5, 7.5≤Bounce≤9, 14≤Roll≤16, 8≤Pitch≤11, 12≤Yaw≤16.

2. The suspension design method according to claim 1, characterized in that, The parameters of the powertrain include the moment of inertia of the powertrain and the coordinates of the center of mass of the powertrain, with different parameters for different powertrains.

3. The suspension design method according to claim 2, characterized in that, The specific operation of calculating the torque shaft of each powertrain based on the parameters of the different powertrains includes: An inertia matrix is ​​established based on the rotational inertia of the powertrain. The eigenvalues ​​of the inertia matrix are the principal moments of inertia of the powertrain relative to its center of mass, and the corresponding eigenvectors are the torque axes of the powertrain. The inertia matrix is ​​as follows: Among them, J xx J is the moment of inertia about the X-axis; yy J is the moment of inertia about the Y-axis; zz J is the moment of inertia about the Z-axis; xy J is the product of inertia about the XY axis; xz J is the product of inertia about the XZ axis; yz It is the product of inertia about the YZ axis.

4. The suspension design method according to claim 1, characterized in that, The specific steps for calculating the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value include: The natural frequency and decoupling rate of each powertrain were calculated using the optimal stiffness values ​​corresponding to each powertrain assembly, as follows: The natural frequency is obtained using formula (1): （1） Where M is the system mass matrix and K is the system stiffness matrix. Here, φ is the frequency matrix, and φ is the mode shape matrix. The system decoupling rate is obtained through formula (2): （2） in, For M's first k OK l Column elements, For the i-th order main array of the system, T k For the energy of the Kth degree of freedom, T i Let be the total energy of the i-th natural frequency.

5. A suspension design device for performing the suspension design method according to any one of claims 1 to 4, characterized in that, include: Acquisition unit, used to acquire parameters of different powertrains; The arrangement position determination unit is used to calculate the torque shaft of each powertrain based on the parameters of different powertrains, and determine the arrangement position of the suspension elastic center according to the arrangement rule of the line connecting the torque shaft and the suspension elastic center. The optimal stiffness value determination unit is used to calculate and obtain the optimal stiffness value of the suspension with the powertrain decoupling rate as the optimization objective, the natural frequency as the constraint condition, and stiffness as the variable. The target stiffness value determination unit calculates the natural frequency and decoupling rate of each powertrain based on the optimal stiffness value, and takes the stiffness value that simultaneously meets the preset natural frequency requirement and the preset decoupling rate requirement as the target stiffness value of the suspension.

6. A computer storage medium, characterized in that, The computer storage medium stores at least one program that is executed by a computer, and when executed by the computer, the at least one program causes the computer to perform the steps in the suspension design method as described in any one of claims 1 to 4.

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