A method, system, device, and medium for estimating a maximum roll stability angle of a vehicle

Abstract

The application provides a vehicle maximum roll stability angle estimation method, system, device and medium to solve the technical problems of large operation difficulty and large error of the existing vehicle roll stability angle test. The method comprises the following steps: obtaining relevant data of the vehicle roll stability angle; calculating the whole vehicle spring-loaded mass center position based on the obtained relevant data; establishing a model for estimating the maximum roll stability angle; and performing constraint and loading on the model, and analyzing and checking the calculation result. Compared with the traditional calculation method, the influence of suspension deformation and tire deformation on the vehicle roll stability is considered in the analysis process, the maximum roll stability angle of the vehicle can be obtained more accurately in the design stage, the design time and cost are saved, and the problem that some overweight and overlength vehicles cannot be measured on the test bench is solved.

Description

Technical Field

[0001] This application relates to the field of vehicle rollover estimation and analysis technology, and in particular to a method, system, device and medium for estimating the maximum roll stability angle of a vehicle. Background Technology

[0002] Vehicle rollover is a significant factor contributing to vehicle safety accidents. Currently, there are two methods for analyzing the maximum roll stability angle of a vehicle: one is to conduct actual measurements using a rollover test bench, and the other is to assume the entire vehicle is a rigid body with its center of mass located on the longitudinal plane of symmetry, and calculate it using the formula β = arctan B / 2H.

[0003] Both methods have drawbacks to varying degrees. The first method carries a significant risk of rollover during actual measurement. Furthermore, due to limitations in test bench capabilities, certain extra-long or extra-heavy vehicles cannot be measured on a test bench. Moreover, this method requires vehicle assembly before testing; if the results do not meet requirements, substantial design modifications are necessary, severely impacting product development. The second method does not consider the influence of suspension system and tire stiffness on roll stability, leading to significant discrepancies between the calculated results and actual values. It is only suitable for estimation and cannot serve as an accurate design basis. Summary of the Invention

[0004] This application provides a method, system, device, and medium for estimating the maximum roll stability angle of a vehicle, in order to solve the technical problems of the high difficulty of operation and large errors in existing vehicle roll stability angle tests.

[0005] On the one hand, this application provides a method for estimating the maximum roll stability angle of a vehicle, the method comprising:

[0006] Step S1: Obtain relevant data on the vehicle roll stability angle;

[0007] Step S2: Based on the acquired relevant data, calculate the position of the sprung center of gravity of the entire vehicle;

[0008] Step S3: Establish a model for estimating the maximum roll stability angle;

[0009] Step S4: Constrain and load the model, analyze and view the calculation results.

[0010] In one implementation of this application, the relevant data specifically includes: the sprung mass of the vehicle, the unsprung mass of the vehicle, and the position of the center of gravity of the sprung mass.

[0011] In one implementation of this application, the model includes: a frame assembly, a front spring front bracket, a front spring rear bracket, and a balance shaft bracket.

[0012] In one implementation of this application, the process of establishing the model specifically includes:

[0013] Establish a point M at the center of mass of the sprung mass of the vehicle;

[0014] Establish a loading coordinate system at point M, which is rotated θ degrees relative to the vehicle coordinate system around the X-axis and has the Z-axis pointing diagonally downwards.

[0015] The frame assembly is rigidly connected to the front spring front bracket, the front spring rear bracket, and the balance shaft bracket.

[0016] Based on parameters such as vehicle wheelbase, track width, and leaf spring length, establish the curves for the suspension and axle. When establishing the leaf spring curve, it is necessary to set a breakpoint at the connection point between the leaf spring and the axle.

[0017] In one implementation of this application, step S4 specifically includes:

[0018] Calculate the length and width of the leaf spring cross-section using the following formula.

[0019]

[0020] Where K is the leaf spring stiffness, E is the material elastic modulus, b is the leaf spring width, h is the leaf spring thickness, and L is the leaf spring length;

[0021] Based on the length and width of the leaf spring section, establish the front leaf spring beam section S. 前 The rear leaf spring beam section S 后 ;

[0022] Establish a rigid connection between the front end of the front spring model and the center of the front leaf spring bracket, and establish a rigid connection between the rear end of the front spring model and the rear leaf spring bracket, thereby releasing the Y-axis rotational freedom at both ends of the front leaf spring.

[0023] A rigid connection is established between the midpoint of the rear leaf spring model and the balance shaft bracket, while releasing the Y-axis rotational degree of freedom of this point to ensure that the rear spring can rotate around the balance shaft;

[0024] Constrain the X, Z, and Y directions of freedom at the three contact points of the left wheels, and constrain the Z direction of freedom at the three contact points of the right wheels;

[0025] The center of gravity of the vehicle is calculated by taking the mass and center of gravity of each component. A point M is created at the center of gravity of the vehicle. A rigid connection is established between point M and the upper wing surface of the frame. A force F is applied at point M, with the direction being obliquely downward along the Z-axis of the loading coordinate system and the magnitude being equal to the sprung mass of the vehicle.

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

[0027] Apply the unsprung mass corresponding to each suspension at the connection point between each tire model and the axle model;

[0028] Create a new static analysis. After the analysis is completed, check the reaction forces at the model point constraints and the Z-direction reaction forces.

[0029] When the reaction force at the tire constraint point is negative, the constraint at that point is released. The θ angle is continuously adjusted based on the result until the constraints of the two tires of the vehicle have been released and the reaction force at the contact point of the third tire is close to 0. At this time, the θ value is the static rollover stability angle of the vehicle.

[0030] In one implementation of this application, the method further includes:

[0031] The cross-sectional dimension S of the simplified tire model is calculated based on the following formula. 轮 ;

[0032]

[0033] Among them, K 轮 R is the tire stiffness, and R is the tire's free radius.

[0034] A simplified beam model of the tire is established, wherein the beam length is equal to the free radius of the tire.

[0035] Secondly, this application also provides a system for estimating the maximum roll stability angle of a vehicle, the system comprising:

[0036] The relevant data acquisition module is used to acquire relevant data on the vehicle's roll stability angle;

[0037] The calculation module is used to calculate the position of the sprung center of gravity of the whole vehicle based on the acquired relevant data;

[0038] The model building module is used to build a model for estimating the maximum roll stability angle;

[0039] The model analysis module is used to constrain and load the model, analyze and view the calculation results.

[0040] Furthermore, this application also provides an estimation device for the maximum roll stability angle of a vehicle, the device comprising:

[0041] At least one processor; and,

[0042] A memory communicatively connected to the at least one processor; wherein,

[0043] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the aforementioned method for estimating the maximum roll stability angle of the vehicle.

[0044] Finally, this application also provides a non-volatile computer storage medium for estimating the maximum roll stability angle of a vehicle, storing computer-executable instructions for executing the aforementioned method for estimating the maximum roll stability angle of a vehicle.

[0045] This application provides a method, system, device, and medium for estimating the maximum roll stability angle of a vehicle. Compared with traditional calculation methods, the analysis process takes into account the influence of suspension deformation and tire deformation on the vehicle's roll stability. The maximum roll stability angle of the vehicle can be obtained more accurately during the design stage, saving design time and costs. It also solves the problem that some overweight and overlength vehicles cannot be tested on a test bench. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0047] Figure 1 A flowchart illustrating a method for estimating the maximum roll stability angle of a vehicle, provided in an embodiment of this application;

[0048] Figure 2 Model diagrams provided for embodiments of this application;

[0049] Figure 3 A diagram illustrating the composition of a vehicle maximum roll stability angle estimation system provided in this application embodiment;

[0050] Figure 4 A schematic diagram of a device for estimating the maximum roll stability angle of a vehicle, provided for an embodiment of this application;

[0051] Figure label: Figure 2 The components are: 1. Frame assembly, 2. Front spring front bracket, 3. Front spring rear bracket, 4. Balance shaft bracket, 5. Axle, 6. Front leaf spring, 7. Rear leaf spring, and 8. Tire. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] This application provides a method, system, device, and medium for estimating the maximum roll stability angle of a vehicle. The technical solutions proposed in this application will be described in detail below with reference to the accompanying drawings.

[0054] Figure 1 A flowchart illustrating a method for estimating the maximum roll stability angle of a vehicle, as provided in an embodiment of this application. Figure 1 As shown, the method mainly includes the following steps:

[0055] Step S1: Obtain relevant data on the vehicle roll stability angle.

[0056] Step S2: Based on the acquired relevant data, calculate the position of the sprung center of gravity of the entire vehicle.

[0057] Step S3: Establish a model for estimating the maximum roll stability angle.

[0058] Step S4: Constrain and load the model, analyze and view the calculation results.

[0059] In this embodiment, a model is first established in CAE software: the frame assembly 1, and then a simplified suspension model. The front end of the front leaf spring curve 6 is located at the center of the connection hole between the leaf spring front bracket 2 and the leaf spring. The rear end of the curve is connected to the center of the front end of the leaf spring intermediate bracket 3 via the simplified curve 8 of the hanger. A point is set at the intersection of the leaf spring curve and the center plane of the first axle. The left and right leaf springs are established in the same way. The axle curve 5 and the tire curve 8 are established on the center plane of the first axle. The axle curve first connects the break point in the middle of the left and right leaf spring curves, and then extends to the wheel track position on both sides. From this point, a line perpendicular to the axle curve along the negative Z-axis is established, with a length equal to the tire radius. Then, simplified models of the second and third axle balanced suspensions are established.

[0060] The rear leaf spring curve 4 has one end on the center plane of the second axle and the other end on the center plane of the third axle. A breakpoint is set at the midpoint between the second and third axles. The left and right leaf spring curves are created in the same way. Finally, simplified models of the axle and tires are created on the second and third axle planes respectively, using the same method as when creating the first axle.

[0061] In this embodiment of the application, based on the actual stiffness of the vehicle leaf spring, the formula is used.

[0062]

[0063] Where K is the leaf spring stiffness, E is the material elastic modulus, b is the leaf spring width, h is the leaf spring thickness, and L is the leaf spring length;

[0064] Based on the length and width of the leaf spring section, establish the front leaf spring beam section S. 前 The rear leaf spring beam section S 后 ;

[0065] A simplified beam model of a tire is established based on the following formula, where the beam length is equal to the free radius of the tire.

[0066]

[0067] Among them, K 轮 R is the tire stiffness, and R is the tire's free radius. Assuming both front and rear axles are rigid, the cross-sections are uniformly represented by circles with a cross-section of 200mm. By establishing beams, the beam cross-sections and corresponding curves are combined, and the entire model is assigned a material with a Poisson's ratio of 0.3 and an elastic modulus of 210GPa.

[0068] Next, establish connections: a rigid connection is established between the front end of the front spring model and the center of the front leaf spring support, and a rigid connection is established between the rear end of the front spring model and the rear leaf spring support, releasing the Y-axis rotational freedom at both ends of the front leaf spring. A rigid connection is established between the midpoint of the rear leaf spring model and the balance shaft support, simultaneously releasing the Y-axis rotational freedom at that point. This ensures that the rear spring can rotate around the balance shaft.

[0069] Constrain the X, Z, and Y directions of freedom at the three wheel contact points on the left, and constrain the Z direction of freedom at the three wheel contact points on the right.

[0070] The center of gravity of the entire vehicle is calculated by taking the mass and center of gravity of each component. A point M is created at the center of gravity, and a rigid connection is established between point M and the upper wing surface of the frame. A force F is applied at point M, directed diagonally downward along the Z-axis of the loading coordinate system, and its magnitude is equal to the sprung mass of the entire vehicle.

[0071] Apply the unsprung mass corresponding to each suspension at the connection point between each tire model and the axle model.

[0072] Create a new static analysis. After the analysis is completed, check the reaction at the model point constraints and check the Z-axis reaction force. When the reaction force at a certain tire constraint is negative, release the constraint at that point. Adjust the θ angle continuously according to the results until the constraints of the two tires of the vehicle have been released and the reaction force at the third tire contact point is close to 0. At this time, the θ value is the static rollover stability angle of the vehicle.

[0073] The method for estimating the maximum roll stability angle of a vehicle according to the embodiments of this application is not limited by the number of axles in the estimation process. It can be used not only to calculate the axle load of three-axle vehicles, but also to calculate the axle load of vehicles with other numbers of axles. The calculation method is simple, and the results are more accurate than existing calculation methods that assume suspension and tire stiffness.

[0074] The above describes a method for estimating the maximum roll stability angle of a vehicle, as provided in this application. Based on the same inventive concept, this application also provides a system for estimating the maximum roll stability angle of a vehicle. Figure 3 A system composition diagram provided for an embodiment of this application, such as Figure 3As shown, the system mainly includes: a relevant data acquisition module 301, used to acquire relevant data on the vehicle roll stability angle; a calculation module 302, used to calculate the position of the sprung center of gravity of the whole vehicle based on the acquired relevant data; a model building module 303, used to build a model for estimating the maximum roll stability angle; and a model analysis module 304, used to constrain and load the model, analyze and view the calculation results.

[0075] The above describes a system for estimating the maximum roll stability angle of a vehicle, as provided in this application. Based on the same inventive concept, this application also provides a device for estimating the maximum roll stability angle of a vehicle. Figure 4 A schematic diagram of a device for estimating the maximum roll stability angle of a vehicle provided in this application embodiment is shown below. Figure 4 As shown, the device mainly includes: at least one processor 401; and a memory 402 communicatively connected to the at least one processor; wherein, the memory 402 stores instructions that can be executed by the at least one processor 401, and the instructions are executed by the at least one processor 401 to enable the at least one processor 401 to perform: acquiring relevant data of the vehicle roll stability angle; calculating the position of the sprung center of gravity of the whole vehicle based on the acquired relevant data; establishing a model for estimating the maximum roll stability angle; constraining and loading the model, and analyzing and viewing the calculation results.

[0076] In addition, this application embodiment also provides a non-volatile computer storage medium for estimating the maximum roll stability angle of a vehicle, storing computer-executable instructions, wherein the computer-executable instructions are configured to: acquire relevant data on the vehicle roll stability angle; calculate the position of the sprung center of gravity of the entire vehicle based on the acquired relevant data; establish a model for estimating the maximum roll stability angle; constrain and load the model; and analyze and view the calculation results.

[0077] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0078] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0080] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0081] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0082] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for estimating the maximum roll stability angle of a vehicle, characterized in that, The method includes: Step S1: Obtain relevant data on the vehicle roll stability angle; Step S2: Based on the acquired relevant data, calculate the position of the sprung center of gravity of the entire vehicle; Step S3: Establish a model for estimating the maximum roll stability angle; Step S4: Constrain and load the model, analyze and view the calculation results; The model establishment process is as follows: Establish a point M at the center of mass of the sprung mass of the whole vehicle; Establish a loading coordinate system at point M, the loading coordinate system is rotated θ degrees relative to the whole vehicle coordinate system around the X-axis, and the Z-axis is obliquely downward; Establish a rigid connection between the frame assembly and the front spring front bracket, the front spring rear bracket, and the balance shaft bracket; Establish the suspension and axle curves according to the vehicle wheelbase, track width, and leaf spring length. When establishing the leaf spring curve, it is necessary to set a breakpoint at the connection position between the leaf spring and the axle; Step S4 specifically includes: Calculate the length and width of the leaf spring cross-section using the following formula. Where K is the leaf spring stiffness, E is the material elastic modulus, b is the leaf spring width, h is the leaf spring thickness, and L is the leaf spring length; Based on the length and width of the leaf spring section, establish the front leaf spring beam section. S 前 Rear leaf spring beam cross section S 后 ; A rigid connection is established between the front end of the front spring model and the center of the front leaf spring bracket, and a rigid connection is established between the rear end of the front spring model and the rear leaf spring bracket, thereby releasing the Y-axis rotational freedom at both ends of the front leaf spring. A rigid connection is established between the midpoint of the rear leaf spring model and the balance shaft bracket, while releasing the Y-axis rotational degree of freedom at that point to ensure that the rear spring can rotate around the balance shaft; Constrain the X, Z, and Y directions of freedom at the three contact points of the left wheels, and constrain the Z direction of freedom at the three contact points of the right wheels; The center of gravity of the vehicle is calculated by taking the mass and center of gravity of each component of the vehicle. A point M is created at the center of gravity of the vehicle. A rigid connection is established between point M and the upper wing surface of the frame. A force F is applied at point M, with the direction being diagonally downward along the Z-axis of the loading coordinate system and the magnitude being equal to the sprung mass of the vehicle. The method further includes: Apply the unsprung mass corresponding to each suspension at the connection point between each tire model and the axle model; Create a new static analysis. After the analysis is completed, check the reaction forces at the model point constraints and the Z-direction reaction forces. When the reaction force at the tire constraint point becomes negative, the constraint at that point is released, and adjustments are made continuously based on the results. θ The angle continues until the constraints on two of the vehicle's tires are released, and the reaction force at the contact point of the third tire is close to zero. θ The value is the vehicle's static rollover stability angle; The method further includes: The cross-sectional dimensions of the simplified tire model are calculated based on the following formula. S 轮 ; in, K 轮 R is the tire stiffness, and R is the tire's free radius. A simplified beam model of the tire is established, wherein the beam length is equal to the free radius of the tire.

2. The method for estimating the maximum roll stability angle of a vehicle according to claim 1, characterized in that, The relevant data specifically includes: the sprung mass of the vehicle, the unsprung mass of the vehicle, and the position of the center of gravity of the sprung mass.

3. The method for estimating the maximum roll stability angle of a vehicle according to claim 1, characterized in that, The model includes: frame assembly, front spring front bracket, front spring rear bracket, and balance shaft bracket.

4. A system for estimating the maximum roll stability angle of a vehicle, using the method for estimating the maximum roll stability angle of a vehicle as described in claim 1, characterized in that, The system includes: The relevant data acquisition module is used to acquire relevant data on the vehicle's roll stability angle; The calculation module is used to calculate the position of the sprung center of gravity of the whole vehicle based on the acquired relevant data; The model building module is used to build a model for estimating the maximum roll stability angle; The model analysis module is used to constrain and load the model, analyze and view the calculation results.

5. A device for estimating the maximum roll stability angle of a vehicle, characterized in that, The device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method for estimating the maximum roll stability angle of a vehicle as described in any one of claims 1-3.

6. A non-volatile computer storage medium for estimating the maximum roll stability angle of a vehicle, storing computer-executable instructions, characterized in that, The computer-executable instructions are used to execute the method for estimating the maximum roll stability angle of a vehicle as described in any one of claims 1-3.

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