Dynamic response analysis method and system for small offset collision vehicle

Abstract

The invention relates to the technical field of vehicle safety, in particular to a small offset collision vehicle dynamic response analysis method and system. The method comprises the following steps: establishing a coordinate system; the method comprises the following steps: establishing a whole vehicle three-degree-of-freedom second-order motion simplified model aiming at sideslip motion under a small deflection collision working condition, including a vehicle dynamic balance equation and a vehicle kinematics equation; and calculating the displacement and the deflection angle of the i-th section in the X and Y directions. The technical scheme can improve the analysis precision and simplify the calculation difficulty.

Description

Technical Field

[0001] The present invention relates to the field of vehicle safety technology, and in particular to a method and system for analyzing the dynamic response of a vehicle in a small-offset collision. Background Art

[0002] Among the various types of traffic accidents, head-on collision is the most common and most dangerous type due to its high incidence and serious casualties. Figure 1 ) is a special form of frontal collision. In small offset collisions, the vehicle's longitudinal beams generally cannot participate in the energy absorption process, resulting in a significant reduction in the components available for collision energy absorption. This undoubtedly increases the difficulty of developing related technologies.

[0003] With the rapid rise of new energy vehicles, small offset collision safety technology faces more severe tests. On the one hand, new energy vehicles are generally heavier in curb weight than traditional fuel vehicles because they are equipped with three-electric systems. The increase in mass significantly increases the kinetic energy of the vehicle during a collision, and places higher demands on the collision energy absorption structure. On the other hand, the high-voltage system of new energy vehicles is at risk of thermal runaway. Once thermal runaway occurs in a collision, it may cause serious safety accidents, so the requirements for collision protection are more stringent. In addition, in order to meet the needs of various aspects such as cruising range and safety performance, new energy vehicles have a high pursuit of lightweight, and widely use lightweight materials such as aluminum alloy and carbon fiber. However, the failure and connection performance of these lightweight materials are difficult to accurately control, which further increases the difficulty of developing vehicle safety performance under small offset collision conditions. Under the condition of small offset collision, the vehicle structure design strategy is mainly divided into hard resistance (refer to Figure 2 ) and sideslip (refer to Figure 3 ) are two types. The hard-impact strategy primarily relies on energy-absorbing components to absorb collision energy. This energy is gradually absorbed through energy-absorbing components in the front cabin and body, such as the anti-collision beam assembly, trunk beam, upper side sills, and seat towers, as well as chassis components such as the front subframe and wheel system. This reduces vehicle speed and minimizes the impact of the barrier on the passenger compartment. However, because the energy-absorbing components in the front cabin are primarily concentrated in the middle of the vehicle, it is difficult for the vehicle to meet the requirements of the hard-impact strategy in small-offset collision conditions, preventing it from fully realizing its advantages.

[0004] In contrast, the side-slip strategy causes the vehicle to slide sideways during a collision, away from the barrier. In a minor offset collision, the barrier exerts a significant Y-direction force on the vehicle, causing it to experience significant Y-acceleration. This shifts the passenger compartment's trajectory completely away from the barrier, effectively avoiding impact and rebound, and reducing the risk of injury. However, a comprehensive theoretical model and effective planning method for the side-slip strategy are currently lacking, making it difficult to accurately predict and optimize the vehicle's dynamic response in minor offset collisions. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and system for analyzing the dynamic response of a vehicle in a small offset collision, which can improve the analysis accuracy and reduce the calculation difficulty.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for analyzing the dynamic response of a vehicle in a small offset collision, comprising: Establish a coordinate system; For the side sliding motion under minor collision conditions, a simplified three-degree-of-freedom second-order motion model of the vehicle is established: The dynamic equilibrium equation of the vehicle is:

[0007] in, m For vehicle test quality, I is the moment of inertia of the vehicle at the center of mass; F x and F y They are the X-direction force and Y-direction force exerted by the barrier on the vehicle when the vehicle collides. a x and a y are the accelerations in the X and Y directions when the vehicle collides, v x and v y are the velocities of the vehicle in the X and Y directions when it collides, d x and d y The displacement of the vehicle in the X and Y directions when it collides; α is the angular acceleration, θ is the deflection angle; The vehicle kinematic equation is:

[0008] in, v x0 and v y0 Vehicles When , the initial velocity in X and Y directions; Calculate the displacement and deflection angle in the X and Y directions of segment i.

[0009] Beneficial effects of the basic solution: By establishing a three-degree-of-freedom, second-order motion model encompassing X- and Y-direction translation and rotation about the center of mass, this approach comprehensively describes the vehicle's dynamic behavior in small-offset collisions (such as 25% offset collisions). This model encompasses key parameters such as displacement, velocity, acceleration, and deflection angle during the collision, providing a solid theoretical foundation for subsequent analytical analysis.

[0010] The highly nonlinear forces and motions of an actual collision are broken down into multiple stages, each assuming constant acceleration (or force). This transforms the complex nonlinear problem into multiple linear problems for analysis. This segmented approach significantly reduces the complexity of modeling and solving, while maintaining a certain level of accuracy, making theoretical analysis more practical.

[0011] By simplifying the nonlinear collision process into multiple linear motions and establishing a two-dimensional mathematical model, the entire dynamic response solution process is made more efficient. Key parameters such as displacement, velocity, acceleration and deflection angle can be directly output, avoiding complex numerical simulation or experimental testing, and greatly improving analysis efficiency. Traditional small-offset collision safety development relies on a large number of real-vehicle collision tests, which are costly and time-consuming. This method uses theoretical models to predict the dynamic response of the vehicle in a collision in advance, provides optimization direction for structural design, reduces the number of tests, shortens the development cycle, and thus significantly reduces development costs. Compared with empirical design or simple simulation, this method is based on a rigorous dynamic model and can more accurately predict the behavior of the vehicle in a collision, helping engineers discover potential problems in the early stages of design, optimize structural design, improve the safety performance of the vehicle in actual collisions, and enhance the market competitiveness of the product.

[0012] This model can accurately describe the dynamic response of a vehicle during a collision, including sideslip trajectory and deflection angle changes, providing a theoretical basis for vehicle structural optimization (such as body stiffness distribution, energy absorption structure design, restraint system matching, etc.), helping to improve the vehicle's safety performance in small offset collisions and meet regulatory and rating requirements.

[0013] By combining standards with established side-slip motion mode evaluation indicators, a vehicle's side-slip behavior in small-offset collisions can be quantitatively evaluated and optimized. This provides clear objectives and evaluation criteria for the design of vehicle passive safety systems (such as body structure and airbag activation logic), helping to implement more rational side-slip control strategies.

[0014] As an implementable preferred solution, a coordinate system is established, including the following contents: In the test site, determine the centerline position of the front axle of the test vehicle and establish a global coordinate system at this position; Determine the center of gravity of the test vehicle and establish a local coordinate system at this location; Mark the starting point of the vehicle's passenger compartment and measure the deformable length of the test vehicle when it collides with the force measuring wall.

[0015] As an implementable preferred solution, the vehicle's side slip value GV p and the vehicle's yaw angle θ Jointly determine the type of vehicle collision motion, including the following: Calculate the response slip value GV p Respond to the sideslip value when the collision ends And the vehicle deflection angle When , it is determined that the vehicle is in a side-slip motion mode; Respond to the sideslip value when the collision ends or vehicle deflection angle When the vehicle is in energy absorption and hard resistance motion mode.

[0016] As an implementable preferred solution, calculate the response sideslip value GV p The formula is as follows:

[0017] in, Represents the displacement of point P along the y-axis during the collision; Represents the edge of the barrier to The distance between them.

[0018] As an implementable preferred solution, the displacement and deflection angle of the i-th segment in the X and Y directions are calculated, including: No. i The displacement of the segment in the X direction is expressed as:

[0019] Calculate the i The displacement of the segment in the Y direction is expressed as:

[0020] Calculate the i The segment deflection angle is expressed as: .

[0021] As an implementable preferred solution, it also includes developing collision planning software for parameter input, including the following: In the overall motion planning section, input the vehicle's overall displacement in the X and Y directions; the initial velocity in the X direction; the vehicle's curb mass; the moment of inertia at the vehicle's center of mass; the distance from the impact point to the center of mass in the X and Y directions; and the average force in the Y direction of the overall plan. Click the button in the overall motion planning section to output the average force in the X direction; In the first motion planning section, input the vehicle's first motion displacement in the X direction and the average forces in the X and Y directions. Click the button in the first stage of motion planning to output the vehicle's deflection angle in the first stage; In the second motion planning section, input the vehicle's second motion displacement in the X direction and the average forces in the X and Y directions. Click the button in the second segment motion planning section to output the average forces in the third segment in the X and Y directions and the vehicle deflection angles in the second and third segments.

[0022] As an implementable preferred solution, after all parameters are output, the vehicle overall force result diagram and the vehicle deflection angle planning result diagram are generated, and the vehicle collision mode is evaluated based on the vehicle overall force result diagram and the vehicle deflection angle planning result diagram.

[0023] In a second aspect, the present invention further provides a small offset collision vehicle dynamic response analysis system, which utilizes the above-mentioned small offset collision vehicle dynamic response analysis method. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the standard model for the 25% deflection test.

[0025] Figure 2 Schematic diagram of energy absorption motion mode.

[0026] Figure 3 Schematic diagram of the sliding motion mode.

[0027] Figure 4 A flowchart of a method for analyzing the dynamic response of a vehicle in a small offset collision is provided in one embodiment of the present invention.

[0028] Figure 5 Schematic diagram of a simplified model of three-degree-of-freedom second-order motion.

[0029] Figure 6 Schematic diagram of the software calculation interface.

[0030] Figure 7 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0031] Reference numerals: electronic device 500 , processor 501 , communication interface 502 , memory 503 , bus 504 . DETAILED DESCRIPTION

[0032] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. It will be understood that the specific embodiments described herein are only partial embodiments of the present invention, which are only used to explain the present application, rather than to limit the present application. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be judged to be isolated, and they can be combined with each other to achieve better technical effects. The same reference numerals appearing in the drawings of the following embodiments represent the same features or components, which can be applied to different embodiments.

[0033] In addition, unless otherwise defined, technical or scientific terms used in the description of the present invention should have the common meanings understood by those skilled in the art in the art to which the present invention belongs.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings: Reference Figure 4 A method for analyzing the dynamic response of a vehicle in a small offset collision is proposed. This method establishes a three-degree-of-freedom second-order motion model for theoretical analysis during the vehicle's small offset collision motion process. At the same time, it simplifies the complex nonlinear collision motion process into multiple segments of linear motion with constant acceleration (force) for analysis. While ensuring the accuracy of the analysis, it greatly simplifies the calculation difficulty and provides guidance for the safe development of small offset collision structures. The method includes the following steps.

[0035] Step S100, establishing a coordinate system, includes: Step S101: In the test site, determine the front axle centerline position of the test vehicle and establish the global coordinate system RF at this position. G .

[0036] Step S102: Determine the COG center of gravity of the test vehicle and establish a local coordinate system RF at this location. CG .

[0037] Step S103 , marking the starting point AP of the vehicle passenger compartment, and measuring the deformable length SL of the test vehicle when it collides with the force measuring wall.

[0038] Step S200: The vehicle's side slip response value GV p and the vehicle's yaw angle θ Jointly determine the type of vehicle collision motion, including Step S201, in the 25% offset test, calculate the response sideslip value GV p , the formula is as follows:

[0039] in, Represents the displacement of point P along the y-axis during the collision process. Point P is the reference point of the AP point projected onto the obstacle avoidance surface along the x-axis. Represents the edge of the barrier to The distance between them.

[0040] Step S202: Determine the vehicle collision type: Respond to the sideslip value when the collision ends And the vehicle deflection angle When , it is determined that the vehicle is in a side-slip motion mode; Respond to the sideslip value when the collision ends or vehicle deflection angle When the vehicle is in energy absorption and hard resistance motion mode.

[0041] Step S300: Establish a simplified model of the vehicle's three-degree-of-freedom second-order motion, referring to Figure 5 The vehicle has the following degrees of freedom: translational freedom in the X and Y directions and rotational freedom in the horizontal plane. When the vehicle hits the barrier, the barrier generates an X-direction force on the vehicle. F x and Y-direction force F y The vehicle generates accelerations in the X and Y directions respectively a x and a y , the speed is v x and v y , the displacement is d x and d y At the same time, the vehicle is F x and F y A rotational torque is formed under the action, and angular acceleration is generated at the center of mass α , the deflection angle is θ .

[0042] Aiming at the side slip problem in small offset collision conditions, a simplified three-degree-of-freedom second-order motion model of the whole vehicle is established.

[0043] The dynamic equilibrium equation of the vehicle is:

[0044] in, m For vehicle test quality, I is the moment of inertia of the vehicle at its center of mass.

[0045] The vehicle kinematic equation is:

[0046] in, v x0 and v y0 Vehicles When , the initial velocity in X and Y directions.

[0047] Step S400, calculating the displacement and deflection angle of the i-th segment in the X and Y directions, including: Step S401, i The displacement of the segment in the X direction is expressed as: .

[0048] Step S402, calculate the i The displacement of the segment in the Y direction can be expressed as: .

[0049] Step S403, calculate the i The segment deflection angle is expressed as: .

[0050] Step S500: Develop collision planning software and input parameters, refer to Figure 6 ,include: Step S501: start collision planning software.

[0051] Step S502: In the overall motion planning section, input the vehicle's overall displacement in the X and Y directions; the initial velocity in the X direction; the vehicle's curb mass; the moment of inertia at the vehicle's center of mass; the distance from the impact point to the center of mass in the X and Y directions; and the average force in the Y direction of the overall plan.

[0052] Step S503: Click the button of the overall motion planning part to output the average force in the X direction.

[0053] Step S504 , in the first motion planning part, the displacement of the vehicle in the first motion segment in the X direction and the average forces received in the first motion segment in the X and Y directions are input.

[0054] Step S505: Click the button of the first motion planning section to output the first stage vehicle deflection angle.

[0055] Step S506 , in the second motion planning part, input the vehicle's second motion displacement in the X direction and the average forces in the X and Y directions for the second motion.

[0056] Step S507: Click the button of the second segment motion planning part to output the average force of the third segment in the X and Y directions and the vehicle deflection angles of the second and third segments.

[0057] Step S600: After all parameters are output, a vehicle overall force result diagram and a vehicle deflection angle planning result diagram are generated, and the vehicle collision mode is judged based on the vehicle overall force result diagram and the vehicle deflection angle planning result diagram.

[0058] This embodiment of the present application also provides an electronic device 500 that utilizes the aforementioned method for analyzing the dynamic response of a vehicle in a small-offset collision. The device includes a memory, a processor, and a computer program stored in the memory and executable by the processor. When the processor executes the program, the steps of the aforementioned method for analyzing the dynamic response of a vehicle in a small-offset collision are implemented. In this embodiment of the present application, the processor serves as the control center of the computer method and can be a processor of a physical machine or a processor of a virtual machine.

[0059] Reference Figure 7 The electronic device 500 includes: at least one processor 501, at least one communication interface 502, at least one memory 503, and at least one bus 504. Bus 504 is used to enable communication between these components, communication interface 502 is used to communicate signaling or data with other node devices, and memory 503 stores machine-readable instructions executable by processor 501. When the electronic device 500 is in operation, processor 501 communicates with memory 503 via bus 504. When the machine-readable instructions are invoked by processor 501, the steps of the method for analyzing the dynamic response of a vehicle in a small offset collision, as described above, are executed.

[0060] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor of an electronic device, it can implement the steps of the method for analyzing the dynamic response of a vehicle in a small offset collision as described above.

[0061] Those skilled in the art will understand that all or part of the process of implementing a method for analyzing the dynamic response of a vehicle in a small offset collision can be accomplished by instructing related hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the process of various embodiments of a method for analyzing the dynamic response of a vehicle in a small offset collision. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0062] The above contents are merely embodiments of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. A person of ordinary skill in the art is aware of all common technical knowledge in the technical field to which the invention belongs before the filing date or priority date, is able to obtain all existing technologies in the field, and has the ability to apply conventional experimental means before that date. A person of ordinary skill in the art can, under the guidance of this application, improve and implement this scheme in combination with his or her own abilities. Some typical known structures or known methods should not become an obstacle for a person of ordinary skill in the art to implement this application. It should be pointed out that for a person of ordinary skill in the art, several variations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for analyzing the dynamic response of a vehicle in a small offset collision, characterized in that: include: Establish a coordinate system; For the side slip motion under minor collision conditions, a simplified three-degree-of-freedom second-order motion model of the vehicle is established: The dynamic equilibrium equation of the vehicle is: in, m For vehicle test quality, I is the moment of inertia of the vehicle at the center of mass; F x and F y They are the X-direction force and Y-direction force exerted by the barrier on the vehicle when the vehicle collides. a x and a y are the accelerations in the X and Y directions when the vehicle collides, v x and v y are the velocities of the vehicle in the X and Y directions when it collides, d x and d y The displacement of the vehicle in the X and Y directions when it collides; α is the angular acceleration, θ is the deflection angle; The vehicle kinematic equation is: in, v x0 and v y0 Vehicles When , the initial velocity in X and Y directions; Calculate the displacement and deflection angle in the X and Y directions of segment i.

2. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 1, characterized in that: Establish a coordinate system, including the following: In the test site, determine the centerline position of the front axle of the test vehicle and establish a global coordinate system at this position; Determine the center of gravity of the test vehicle and establish a local coordinate system at this location; Mark the starting point of the vehicle's passenger compartment and measure the deformable length of the test vehicle when it collides with the force measuring wall.

3. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 1, characterized in that: The vehicle's response side slip value GV p and the vehicle's yaw angle θ Jointly determine the type of vehicle collision motion, including the following: Calculate the response slip value GV p Respond to the sideslip value when the collision ends And the vehicle deflection angle When , it is determined that the vehicle is in a side-slip motion mode; Respond to the sideslip value when the collision ends or vehicle deflection angle When the vehicle is in energy absorption and hard resistance motion mode.

4. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 3, characterized in that: Calculate the response slip value GV p The formula is as follows: in, Represents the displacement of point P along the y-axis during the collision; Represents the edge of the barrier to The distance between them.

5. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 1, characterized in that: Calculate the displacement and deflection angle of the i-th segment in the X and Y directions, including: No. i The displacement of the segment in the X direction is expressed as: Calculate the i The displacement of the segment in the Y direction is expressed as: Calculate the i The segment deflection angle is expressed as: 。 6. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 5, characterized in that: It also includes the development of collision planning software for parameter input, including the following: In the overall motion planning section, input the vehicle's overall displacement in the X and Y directions; the initial velocity in the X direction; the vehicle's curb mass; the moment of inertia at the vehicle's center of mass; the distance from the impact point to the center of mass in the X and Y directions; and the average force in the Y direction of the overall plan. Click the button in the overall motion planning section to output the average force in the X direction; In the first motion planning section, input the vehicle's first motion displacement in the X direction and the average forces in the X and Y directions. Click the button in the first stage of motion planning to output the vehicle's deflection angle in the first stage; In the second motion planning section, input the vehicle's second motion displacement in the X direction and the average forces in the X and Y directions. Click the button in the second segment motion planning section to output the average forces in the third segment in the X and Y directions and the vehicle deflection angles in the second and third segments.

7. The method for analyzing the dynamic response of a vehicle in a small offset collision according to claim 1, characterized in that: After all parameters are output, the vehicle overall force result diagram and the vehicle deflection angle planning result diagram are generated. The vehicle collision mode is judged based on the vehicle overall force result diagram and the vehicle deflection angle planning result diagram.

8. A small offset collision vehicle dynamic response analysis system, characterized by: A method for analyzing the dynamic response of a vehicle in a small offset collision as described in any one of claims 1 to 7 is used.

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