Commercial vehicle braking deviation optimization method and system

Abstract

The invention discloses a commercial vehicle braking deviation optimization method and system, and the method comprises the steps: building a rigid body suspension steering system multi-body dynamic model and a flexible body suspension steering system multi-body dynamic model according to vehicle suspension steering parameters, and building reference points at knuckle arm points and main pin points of the models; setting a plurality of basic working conditions according to the size of the load, and enabling the rigid body suspension steering system multi-body dynamic model and the flexible body suspension steering system multi-body dynamic model to respectively simulate and run the plurality of basic working conditions; extracting the turning angle variable quantity of the wheel, the track of the knuckle arm point and the track of the kingpin point in the simulation process, and respectively calculating the turning angle variable quantity and the point position interference quantity caused by each influence factor according to a set rule; and on the basis of the rotation angle variable quantity and the point position interference quantity, the contribution proportion of each influence factor is obtained, and part arrangement is optimized according to the point position interference quantity so as to reduce the braking deviation quantity.

Description

Technical Field

[0001] The present application relates to the field of vehicle braking technology, and in particular to a method and system for optimizing braking deviation of a commercial vehicle. Background Art

[0002] Commercial vehicle brake deviation has always been a difficult problem in the industry. There are many influencing factors and the influencing mechanism is complex. The most important thing in the study of brake deviation is the calculation of the brake interference angle, and then the prediction of the brake deviation amount. Previous studies mainly used drawing methods and multi-body dynamics methods, mainly considering the influence of horizontal jump interference and longitudinal torsional deformation of leaf springs, and calculating and analyzing the interference amount of brake deviation from the overall perspective. However, this analysis method cannot reflect the contribution of influencing factors, and cannot analyze the influence of components on the brake deviation amount, and cannot provide optimization suggestions from the component level.

[0003] During vehicle braking, the deformation of the front axle I-beam, the torsional deformation of the leaf spring, and the jumping interference of the leaf spring are the main factors causing the brake deviation problem. In view of this, in order to fundamentally correct the deviation problem during braking, these multi-dimensional factors must be considered comprehensively. The previous solution strategy was limited to only starting from the level of horizontal jump interference, and reducing the mutual interference between the leaf spring and the steering system by fine-tuning the path of the leaf spring and the straight pull rod. However, this method cannot reflect the contribution of horizontal jump interference to brake deviation, so reducing horizontal jump interference alone cannot fundamentally solve the brake deviation problem. Summary of the invention

[0004] The present application provides a commercial vehicle brake deviation optimization method and system to solve the above-mentioned problems.

[0005] On the one hand, the present application provides a method for optimizing braking deviation of a commercial vehicle, the method comprising the following steps:

[0006] Step S1: According to the vehicle suspension steering parameters, a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model are established respectively, and reference points are established at the knuckle point and the kingpin point of the model respectively;

[0007] Step S2: setting a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions;

[0008] Step S3: extracting the wheel angle variation, the trajectory of the knuckle point and the trajectory of the kingpin point during the simulation process, and calculating the angle variation and point interference caused by each influencing factor according to the set rules;

[0009] Step S4: Based on the angle change and the point interference, the contribution ratio of each influencing factor is obtained, and the component layout is optimized according to the point interference to reduce the braking deviation.

[0010] In one implementation of the present application, the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model both include a leaf spring subsystem, an axle subsystem and a steering subsystem.

[0011] In one implementation of the present application, the axle I-beam in the rigid body suspension steering system multi-body dynamics model is a rigid body, and the flexible body suspension steering system multi-body dynamics model imports a flexible body file containing the I-beam during the simulation process.

[0012] In one implementation of the present application, the basic working condition specifically includes a flat jump simulation working condition, a first braking simulation working condition and a second braking simulation working condition.

[0013] In one implementation of the present application, the method further includes:

[0014] The multi-body dynamics model of the rigid suspension steering system and the multi-body dynamics model of the flexible suspension steering system are simulated to run the flat jump simulation condition, the first braking simulation condition and the second braking simulation condition respectively, and the flexible bridge flat jump condition, the flexible bridge first braking simulation condition, the flexible bridge second braking simulation condition, the rigid bridge flat jump condition, the rigid bridge first braking simulation condition and the rigid bridge second braking simulation condition are obtained.

[0015] In one implementation of the present application, in step S3, extracting the wheel angle change during the simulation process specifically includes:

[0016] The wheel turning angle δ caused by bridge deformation is calculated based on the following formula axle :

[0017] δ axle =δ3-δ6-(δ1-δ4)

[0018] Among them, δ1 is the wheel angle obtained in the flexible bridge flat jump condition, δ3 is the wheel angle obtained in the flexible bridge second braking simulation condition, δ4 is the wheel angle obtained in the rigid bridge flat jump condition, and δ6 is the wheel angle obtained in the rigid bridge second braking simulation condition;

[0019] The displacement interference x between the kingpin and the joint arm caused by the bridge deformation is calculated based on the following formula axle :

[0020]

[0021] Among them, x a1 、x b1are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a3 、x b3 are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a4 、x b4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 The x-direction displacements of the joint arm point and the kingpin point are obtained for the second braking simulation condition of the rigid bridge. By extracting the influence and sensitivity of the bridge deformation, the tire angle change caused by the bridge deformation is calculated based on the results and the contribution to the total interference angle is evaluated.

[0022] In one implementation of the present application, the method further includes:

[0023] The wheel turning angle δ caused by flat jump is calculated based on the following formula bump change:

[0024] δ bump =δ4

[0025] Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition, and the kingpin and joint arm point displacement interference caused by flat jump x bump :x bump =x a4 -x b4 , where x a4 、x b4 The x-direction displacements of the joint arm point and the kingpin point are obtained for the rigid bridge flat jump condition. The influence and sensitivity of the longitudinal torsional deformation of the leaf spring are extracted, and the tire angle change caused by the longitudinal torsional deformation of the leaf spring is calculated based on the results, and the contribution to the total interference angle is evaluated.

[0026] In one implementation of the present application, the method further includes:

[0027] The wheel turning angle δ caused by the elongation of the leaf spring is calculated based on the following formula leaf change:

[0028] δ leaf =δ6-δ4

[0029] Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition; δ6 is the wheel angle obtained from the second braking simulation condition of the rigid bridge; the kingpin and joint arm point displacement interference caused by the elongation deformation of the leaf spring x leaf :x leaf =x a6 -x a4 -(x b6 -x b4 ), where x a4 、xb4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the rigid bridge;

[0030] The wheel turning angle δ caused by bridge sag is calculated based on the following formula ver change:

[0031] δ ver =δ1-δ4

[0032] Among them, δ1 is the wheel angle obtained under the flexible bridge flat jump condition; δ4 is the wheel angle obtained under the rigid bridge flat jump condition; by extracting the influence and sensitivity of the interference between the tie rod and leaf spring trajectories, the change of tire angle caused by the interference between the tie rod and leaf spring trajectories is obtained according to the results, and the contribution to the total interference angle is evaluated.

[0033] The interference amount x between the kingpin and the joint arm caused by the bridge sag is calculated based on the following formula ver :

[0034] x ver =(x a1 -x a4 )-(x b1 -x b4 )

[0035] x a1 、x b1 are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a4 、x b4 The x-direction displacements of the joint arm point and the kingpin point are obtained for the rigid bridge flat jump condition. By extracting the influence and sensitivity of the vertical bending of the bridge, the tire angle change caused by the vertical bending of the bridge is calculated according to the results, and the contribution to the total interference angle is evaluated. By extracting the influence and sensitivity of the torsional deformation of the bridge, the tire angle change caused by the torsion of the bridge is calculated according to the results, and the contribution to the total interference angle is evaluated.

[0036] In one implementation of the present application, the method further includes:

[0037] The wheel turning angle δ caused by the deformation of the leaf spring S is calculated based on the following formula S change:

[0038] δ s =δ5-δ6

[0039] Among them, δ5 is the wheel angle obtained by the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained by the second braking simulation condition of the rigid bridge;

[0040] The displacement interference x between the kingpin and the joint arm caused by the deformation of the leaf spring S is calculated based on the following formula S :

[0041] x s =x a5 -x a6 -(x b5 -x b6 )

[0042] Among them, x a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 The x-direction displacements of the joint arm point and the kingpin point obtained for the second braking simulation condition of the rigid bridge are:

[0043] The wheel turning angle δ caused by bridge torsion is calculated based on the following formula s_axle change:

[0044] δ axles =δ2-δ3-(δ5-δ6)

[0045] Among them, δ2 is the wheel angle obtained in the first braking simulation condition of the flexible bridge; δ3 is the wheel angle obtained in the second braking simulation condition of the flexible bridge; δ5 is the wheel angle obtained in the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained in the second braking simulation condition of the rigid bridge;

[0046] The interference amount x between the kingpin and the joint arm point displacement caused by the bridge torsion is calculated based on the following formula s_axle :

[0047]

[0048] Among them, x a2 、x b2 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the flexible bridge; a3 、x b3 are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained for the second braking simulation condition of the rigid bridge.

[0049] On the other hand, the present application also provides a commercial vehicle brake deviation optimization system, the system comprising:

[0050] A modeling unit is used to establish a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model according to the vehicle suspension steering parameters, and to establish reference points at the joint arm point and the kingpin point of the model respectively;

[0051] A simulation unit, used for setting a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions;

[0052] A calculation unit, used to extract the wheel angle variation, the trajectory of the knuckle point and the trajectory of the kingpin point during the simulation process, and calculate the angle variation and point interference caused by each influencing factor according to the set rules;

[0053] The optimization unit is used to obtain the contribution ratio of each influencing factor based on the angle change and the point interference amount, and optimize the component layout according to the point interference amount to reduce the braking deviation.

[0054] The present application provides a commercial vehicle brake deviation optimization method and system, which can demonstrate the influence of bridge deformation on the brake deviation interference amount and extract the contribution of bridge deformation by establishing a rigid body model and a flexible body model. By setting different simulation conditions, different conditions have different force effects on parts, causing different deformations of parts and components, and the interference amounts caused are also different, so as to analyze the interference contributions of different deformations. Starting from the underlying logic of the influencing mechanism, the present application comprehensively and deeply analyzes how multiple factors such as leaf spring deformation, I-beam structural changes, and leaf spring distortion are superimposed to jointly cause interference phenomena. The present method quantifies the contribution value and relative weight of each influencing factor, and on this basis, locks in the factors that have the most significant impact on the interference amount, and applies targeted optimization measures to better solve the brake deviation problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0056] Figure 1 A flow chart of a commercial vehicle braking deviation optimization method provided in an embodiment of the present application;

[0057] Figure 2 A diagram showing the composition of a commercial vehicle braking deviation optimization system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0060] The embodiment of the present application provides a method and system for optimizing the braking deviation of a commercial vehicle, the purpose of which is to design a method for decomposing the influencing factors of the braking interference amount, combine and analyze multiple working conditions, and decompose the quantitative indicators of multiple influencing factors such as axle deformation, leaf spring longitudinal torsional deformation, and horizontal jump interference. The braking deviation analysis method is designed by separately calculating the rigid bridge and flexible bridge models, vertical loads and vertical and longitudinal combined loads, wheel center loading and tire contact point loading for multiple working conditions, and separately calculating the interference amount and interference angle. After combined calculation, the interference amount of different influencing factors is obtained to predict the braking deviation of the whole vehicle. By analyzing the size of the interference amount of different influencing factors, the optimization direction of the components is obtained. The technical solution proposed in the embodiment of the present application is described in detail below with the help of the accompanying drawings.

[0061] Figure 1 A flow chart of a commercial vehicle braking deviation optimization method provided in an embodiment of the present application. Figure 1 As shown, the method mainly includes the following steps:

[0062] Step S1: According to the vehicle suspension steering parameters, a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model are established respectively, and reference points are established at the knuckle point and the kingpin point of the model respectively;

[0063] Step S2: setting a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions;

[0064] Step S3: extracting the wheel angle variation, the trajectory of the knuckle point and the trajectory of the kingpin point during the simulation process, and calculating the angle variation and point interference caused by each influencing factor according to the set rules;

[0065] Step S4: Based on the angle change and the point interference, the contribution ratio of each influencing factor is obtained, and the component layout is optimized according to the point interference to reduce the braking deviation.

[0066] In an embodiment of the present application, the axle I-beam in the rigid body suspension steering system multi-body dynamics model is a rigid body, and the flexible body suspension steering system multi-body dynamics model imports a flexible body file containing the I-beam during the simulation process.

[0067] In the embodiment of the present application, the basic working condition specifically includes a flat jump simulation condition, a first braking simulation condition, and a second braking simulation condition. The rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model are used to simulate and run the flat jump simulation condition, the first braking simulation condition, and the second braking simulation condition, respectively, to obtain the flexible bridge flat jump condition (simulation condition 1), the flexible bridge first braking simulation condition (simulation condition 2), the flexible bridge second braking simulation condition (simulation condition 3), the rigid bridge flat jump condition (simulation condition 4), the rigid bridge first braking simulation condition (simulation condition 5), and the rigid bridge second braking simulation condition (simulation condition 6).

[0068] In the embodiment of the present application, reference points are established at the joint arm point and the kingpin point in the model axle subsystem, and displacement measurement of the reference points is established. The displacement of the reference points in the x direction is represented by x a and x b ; Set the flat jump simulation condition, set the upper and lower limits of the vertical force load to 13720N and 21952N respectively; Set the braking simulation condition 1, set the upper and lower limits of the vertical force load to 13720N and 21952N respectively, the upper and lower limits of the longitudinal force load to 0 and 13720N respectively, and set the force loading point to the wheel center. Set the braking simulation condition 2, set the upper and lower limits of the vertical force load to 13720N and 21952N respectively, the upper and lower limits of the longitudinal force load to 0 and 13720N respectively, and set the force loading point to the tire contact point.

[0069] The above three basic working conditions are applied to the rigid body model and the flexible body model respectively, and the result files of six simulation conditions are obtained, namely simulation conditions 1-6.

[0070] Furthermore, the wheel angle change δ of the simulation results is extracted in post-processing i And the displacement change x of the two reference points in the x direction ai 、x bi , the model simulation results are shown in Table 1.

[0071] Table 1 Model simulation results

[0072]

[0073] In the embodiment of the present application, the wheel turning angle δ caused by bridge deformation is calculated based on the following formula: axle :

[0074] δ axle =δ3-δ6-(δ1-δ4)

[0075] Among them, δ1 is the wheel angle obtained in the flexible bridge flat jump condition, δ3 is the wheel angle obtained in the flexible bridge second braking simulation condition, δ4 is the wheel angle obtained in the rigid bridge flat jump condition, and δ6 is the wheel angle obtained in the rigid bridge second braking simulation condition;

[0076] The displacement interference x between the kingpin and the joint arm caused by the bridge deformation is calculated based on the following formula axle :

[0077]

[0078] Among them, x a1 、x b1 are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a3 、x b3 are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a4 、x b4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 The x-direction displacements of the joint arm point and the kingpin point are obtained for the second braking simulation condition of the rigid bridge. By extracting the influence and sensitivity of the bridge deformation, the tire angle change caused by the bridge deformation is calculated based on the results and the contribution to the total interference angle is evaluated.

[0079] In one implementation of the present application, the method further includes:

[0080] The wheel turning angle δ caused by flat jump is calculated based on the following formula bump change:

[0081] δ bump =δ4

[0082] Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition, and the kingpin and joint arm point displacement interference caused by flat jump x bump :x bump =x a4 -x b4 , where x a4 、x b4 The x-direction displacements of the joint arm point and the kingpin point are obtained for the rigid bridge flat jump condition. The influence and sensitivity of the longitudinal torsional deformation of the leaf spring are extracted, and the tire angle change caused by the longitudinal torsional deformation of the leaf spring is calculated based on the results, and the contribution to the total interference angle is evaluated.

[0083] In one implementation of the present application, the method further includes:

[0084] The wheel turning angle δ caused by the elongation of the leaf spring is calculated based on the following formula leaf change:

[0085] δ leaf =δ6-δ4

[0086] Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition; δ6 is the wheel angle obtained from the second braking simulation condition of the rigid bridge; the kingpin and joint arm point displacement interference caused by the elongation deformation of the leaf spring x leaf :x leaf =x a6 -x a4 -(x b6 -x b4 ), where x a4 、x b4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the rigid bridge;

[0087] The wheel turning angle δ caused by bridge sag is calculated based on the following formula ver change:

[0088] δ ver =δ1-δ4

[0089] Among them, δ1 is the wheel angle obtained under the flexible bridge flat jump condition; δ4 is the wheel angle obtained under the rigid bridge flat jump condition; by extracting the influence and sensitivity of the interference between the tie rod and leaf spring trajectories, the change of tire angle caused by the interference between the tie rod and leaf spring trajectories is obtained according to the results, and the contribution to the total interference angle is evaluated.

[0090] The interference amount x between the kingpin and the joint arm caused by the bridge sag is calculated based on the following formula ver :

[0091] x ver =(x a1 -x a4 )-(x b1 -x b4 )

[0092] x a1 、x b1 are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a4 、x b4 The x-direction displacements of the joint arm point and the kingpin point are obtained for the rigid bridge flat jump condition. By extracting the influence and sensitivity of the vertical bending of the bridge, the tire angle change caused by the vertical bending of the bridge is calculated according to the results, and the contribution to the total interference angle is evaluated. By extracting the influence and sensitivity of the torsional deformation of the bridge, the tire angle change caused by the torsion of the bridge is calculated according to the results, and the contribution to the total interference angle is evaluated.

[0093] In one implementation of the present application, the method further includes:

[0094] The wheel turning angle δ caused by the deformation of the leaf spring S is calculated based on the following formula S change:

[0095] δ s =δ5-δ6

[0096] Among them, δ5 is the wheel angle obtained by the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained by the second braking simulation condition of the rigid bridge;

[0097] The displacement interference x between the kingpin and the joint arm caused by the deformation of the leaf spring S is calculated based on the following formula S :

[0098] x s =x a5 -x a6 -(x b5 -x b6 )

[0099] Among them, x a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the rigid bridge;

[0100] The wheel turning angle δ caused by bridge torsion is calculated based on the following formula s_axle change:

[0101] δ axles =δ2-δ3-(δ5-δ6)

[0102] Among them, δ2 is the wheel angle obtained in the first braking simulation condition of the flexible bridge; δ3 is the wheel angle obtained in the second braking simulation condition of the flexible bridge; δ5 is the wheel angle obtained in the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained in the second braking simulation condition of the rigid bridge;

[0103] The interference amount x between the kingpin and the joint arm point displacement caused by the bridge torsion is calculated based on the following formula s_axle :

[0104]

[0105] Among them, x a2 、x b2 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the flexible bridge; a3 、x b3are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained for the second braking simulation condition of the rigid bridge.

[0106] Finally, the obtained interference amounts under various factors are shown in Table 2 below.

[0107] Table 2 Interference scale of various influencing factors of commercial vehicle brake deviation

[0108]

[0109] Through the above analysis, the bridge deformation contributes the most, and the bridge deformation and the leaf spring S deformation exist simultaneously during the braking process, so the optimization idea is to focus on reducing the interference of the bridge deformation and increase the contribution of the leaf spring S deformation. The specific method is to increase the longitudinal bending stiffness of the bridge and raise the joint arm point above the torsion center of the leaf spring. In the embodiment of this application, the joint arm height is increased by 46mm, the interference angle is reduced from 0.9 degrees to 0.1 degrees, and the braking deviation is reduced from 3 meters to less than 0.5 meters.

[0110] The above is a commercial vehicle brake deviation optimization method provided by an embodiment of the present application. Based on the same inventive concept, an embodiment of the present application also provides a commercial vehicle brake deviation optimization system. Figure 2 A composition diagram of a commercial vehicle braking deviation optimization system provided in an embodiment of the present application, such as Figure 2As shown, the system mainly includes: a modeling unit 201, which is used to establish a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model according to the vehicle suspension steering parameters, and to establish reference points at the knuckle points and kingpin points of the models respectively; a simulation unit 202, which is used to set a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions; a calculation unit 203, which is used to extract the wheel angle change, the knuckle point trajectory and the kingpin point trajectory during the simulation process, and calculate the angle change and point interference caused by each influencing factor according to the set rules; an optimization unit 204, which is used to obtain the contribution ratio of each influencing factor based on the angle change and the point interference, and optimize the component layout according to the point interference to reduce the braking deviation. The embodiment of the present application can analyze the contribution of different factors affecting brake deviation. Different leaf spring shapes, such as multiple leaf springs or fewer leaf springs, and different bridge stiffness models will result in different impacts. Each influencing factor is decomposed, the overall interference of the system is quantified and associated with the deformation of each component, making the analysis more accurate and intuitive.

[0111] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0112] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0113] The above is only the embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A commercial vehicle braking deviation optimization method, characterized in that: The method comprises the following steps: Step S1: establishing a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model according to the vehicle suspension steering parameters, and establishing reference points at the knuckle point and the kingpin point of the model respectively; Step S2: setting a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions; Step S3: extracting the wheel angle variation, the trajectory of the knuckle point and the trajectory of the kingpin point during the simulation process, and calculating the angle variation and point interference caused by each influencing factor according to the set rules; Step S4: Based on the angle change and the point interference, the contribution ratio of each influencing factor is obtained, and the component layout is optimized according to the point interference to reduce the braking deviation.

2. A commercial vehicle brake deviation optimization method according to claim 1, characterized in that: The rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model both include a leaf spring subsystem, an axle subsystem and a steering subsystem.

3. A commercial vehicle brake deviation optimization method according to claim 2, characterized in that: The axle I-beam in the rigid body suspension steering system multi-body dynamics model is a rigid body, and the flexible body file containing the I-beam is imported into the flexible body multi-body dynamics model of the flexible body suspension steering system during the simulation process.

4. A commercial vehicle brake deviation optimization method according to claim 1, characterized in that: The basic working conditions specifically include a flat jump simulation condition, a first braking simulation condition and a second braking simulation condition.

5. A commercial vehicle brake deviation optimization method according to any one of claims 1 or 4, characterized in that: The method further comprises: The multi-body dynamics model of the rigid suspension steering system and the multi-body dynamics model of the flexible suspension steering system are simulated to run the flat jump simulation condition, the first braking simulation condition and the second braking simulation condition respectively, and the flexible bridge flat jump condition, the flexible bridge first braking simulation condition, the flexible bridge second braking simulation condition, the rigid bridge flat jump condition, the rigid bridge first braking simulation condition and the rigid bridge second braking simulation condition are obtained.

6. A commercial vehicle brake deviation optimization method according to any one of claims 1 or 5, characterized in that: In step S3, the wheel angle variation during the simulation is extracted, specifically including: The wheel turning angle δ caused by bridge deformation is calculated based on the following formula axle : d axle =δ3-δ6-(δ1-δ4) Among them, δ1 is the wheel angle obtained in the flexible bridge flat jump condition, δ3 is the wheel angle obtained in the flexible bridge second braking simulation condition, δ4 is the wheel angle obtained in the rigid bridge flat jump condition, and δ6 is the wheel angle obtained in the rigid bridge second braking simulation condition; The displacement interference x between the kingpin and the joint arm caused by the bridge deformation is calculated based on the following formula axle : Among them, x a1 、x b1 are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a3 、x b3 are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a4 、x b4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained for the second braking simulation condition of the rigid bridge.

7. A commercial vehicle brake deviation optimization method according to claim 6, characterized in that: The method further comprises: The wheel turning angle δ caused by flat jump is calculated based on the following formula bump change: d bump =δ4 Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition, and the kingpin and joint arm point displacement interference caused by flat jump x bump :x bump =x a4 -x b4 , where x a4 、x b4 The x-direction displacements of the boom point and the kingpin point obtained for the rigid bridge horizontal jump condition respectively.

8. A commercial vehicle brake deviation optimization method according to claim 6, characterized in that: The method further comprises: The wheel turning angle δ caused by the elongation of the leaf spring is calculated based on the following formula leaf change: d leaf =δ6-δ4 Among them, δ4 is the wheel angle obtained from the rigid bridge flat jump condition; δ6 is the wheel angle obtained from the second braking simulation condition of the rigid bridge; the kingpin and joint arm point displacement interference caused by the elongation deformation of the leaf spring x leaf :x leaf =x a6 -x a4 -(x b6 -x b4 ), where x a4 、x b4 are the x-direction displacements of the joint arm point and the kingpin point obtained under the rigid bridge horizontal jump condition; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the rigid bridge; The wheel turning angle δ caused by bridge sag is calculated based on the following formula ver change: d ver =δ1-δ4 Among them, δ1 is the wheel angle obtained under the flexible bridge flat jump condition; δ4 is the wheel angle obtained under the rigid bridge flat jump condition; The interference amount x between the kingpin and the joint arm caused by the bridge sag is calculated based on the following formula ver : x ver =(x a1 -x a4 )-(x b1 -x b4 ) x a1 、x b1 are the x-direction displacements of the joint arm point and the kingpin point obtained under the flexible bridge horizontal jump condition; a4 、x b4 The x-direction displacements of the boom point and the kingpin point obtained for the rigid bridge horizontal jump condition respectively.

9. A commercial vehicle brake deviation optimization method according to claim 6, characterized in that: The method further comprises: The wheel turning angle δ caused by the deformation of the leaf spring S is calculated based on the following formula S change: d s =δ5-δ6 Among them, δ5 is the wheel angle obtained by the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained by the second braking simulation condition of the rigid bridge; The displacement interference x between the kingpin and the joint arm caused by the deformation of the leaf spring S is calculated based on the following formula S : x s =x a5 -x a6 -(x b5 -x b6 ) Among them, x a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the rigid bridge; The wheel turning angle δ caused by bridge torsion is calculated based on the following formula s_axle change: d axles =δ2-δ3-(δ5-δ6) Among them, δ2 is the wheel angle obtained in the first braking simulation condition of the flexible bridge; δ3 is the wheel angle obtained in the second braking simulation condition of the flexible bridge; δ5 is the wheel angle obtained in the first braking simulation condition of the rigid bridge; δ6 is the wheel angle obtained in the second braking simulation condition of the rigid bridge; The interference amount x between the kingpin and the joint arm point displacement caused by the bridge torsion is calculated based on the following formula s_axle : Among them, x a2 、x b2 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the flexible bridge; a3 、x b3 are the x-direction displacements of the joint arm point and the kingpin point obtained from the second braking simulation condition of the flexible bridge; a5 、x b5 are the x-direction displacements of the joint arm point and the kingpin point obtained from the first braking simulation condition of the rigid bridge; a6 、x b6 They are the x-direction displacements of the joint arm point and the kingpin point obtained for the second braking simulation condition of the rigid bridge.

10. A commercial vehicle braking deviation optimization system, characterized in that: The system comprises: A modeling unit is used to establish a rigid body suspension steering system multi-body dynamics model and a flexible body suspension steering system multi-body dynamics model according to the vehicle suspension steering parameters, and to establish reference points at the joint arm point and the kingpin point of the model respectively; A simulation unit, used for setting a number of basic working conditions according to the load size, so that the rigid body suspension steering system multi-body dynamics model and the flexible body suspension steering system multi-body dynamics model respectively simulate and run a number of basic working conditions; A calculation unit, used to extract the wheel angle variation, the trajectory of the knuckle point and the trajectory of the kingpin point during the simulation process, and calculate the angle variation and point interference caused by each influencing factor according to the set rules; The optimization unit is used to obtain the contribution ratio of each influencing factor based on the angle change and the point interference amount, and optimize the component layout according to the point interference amount to reduce the braking deviation.

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