Simulation test methods, apparatus and computer equipment for battery pack drop tests

Abstract

The present application relates to the field of testing technology, and in particular to a simulation test method, device and computer equipment for battery pack falling. The method includes: monitoring the falling process of a battery pack simulation model, the battery pack simulation model includes multiple contact surfaces, and each contact surface has a corresponding contact condition; when the trigger condition corresponding to the target contact surface among the multiple contact surfaces is detected to be triggered, determining the contact forces corresponding to each of the multiple moments of the battery pack simulation model during the falling process; determining the falling speed and falling angle of the battery pack simulation model when it falls to an obstacle based on the contact forces corresponding to each of the multiple moments; and generating the falling test results of the battery pack simulation model based on the falling speed and falling angle. The use of this method can make the test results closer to the actual falling speed and angle, and its credibility and practicality will be significantly improved.

Description

Technical Field

[0001] The present application relates to the field of testing technology, and in particular to a battery pack drop simulation testing method, device and computer equipment. Background Art

[0002] With the rapid development of the energy storage industry, battery packs for energy storage have been widely used. As an indispensable part of various tests for battery packs, the drop performance test directly affects the quality of the battery pack products. Generally, before the drop test, simulation technicians will perform drop simulation on the battery pack to verify and optimize the design, shorten the R&D cycle, and reduce R&D costs.

[0003] However, in order to improve the simulation speed, simulation technicians in the industry currently mainly input the drop speed through formula calculation, and the drop angle is assumed by default that the positive and negative panels of the battery pack fall vertically toward the ground. There is a certain deviation between the parameters obtained in this way and the actual situation, so the final simulation results are not very accurate. Summary of the invention

[0004] Based on this, it is necessary to provide a battery pack drop simulation test method, device, computer equipment, computer-readable storage medium and computer program product that can improve the accuracy of battery pack drop simulation results in response to the above-mentioned technical problems.

[0005] In a first aspect, the present application provides a battery pack drop simulation test method, comprising:

[0006] Starting a falling process monitoring of a battery pack simulation model, the battery pack simulation model comprising a plurality of contact surfaces, each of the contact surfaces having a corresponding contact condition;

[0007] When it is monitored that a trigger condition corresponding to a target contact surface among the multiple contact surfaces is triggered, determining the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process;

[0008] Determining a falling speed and a falling angle of the battery pack simulation model when it falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0009] A drop test result of the battery pack simulation model is generated according to the drop speed and the drop angle.

[0010] In one of the embodiments, the battery pack simulation model includes multiple components, and the drop test result includes a deformation representation of the component to which the target contact surface belongs;

[0011] The step of generating a drop test result of the battery pack simulation model according to the drop speed and the drop angle includes:

[0012] Determining a drop angular velocity of the battery pack simulation model according to the drop velocity and the drop angle;

[0013] Determine the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model;

[0014] The deformation characterization quantity of the component to which the target contact surface belongs is determined according to the falling angular velocity and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model.

[0015] In one embodiment, determining the deformation characterization amount of the component to which the target contact surface belongs according to the drop angular velocity and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model includes:

[0016] Obtaining a preset density of the battery pack simulation model;

[0017] Determine the stress of each contact point on the target contact surface according to the preset density, the drop angular velocity, and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model;

[0018] The deformation characterization amount of the component to which the target contact surface belongs is determined based on the stress of each contact point on the target contact surface.

[0019] In one of the embodiments, the battery pack simulation model includes multiple components, and the drop test result includes a collision characterization quantity of each component;

[0020] The step of generating a drop test result of the battery pack simulation model according to the drop speed and the drop angle includes:

[0021] Obtaining the displacement change between each component in the battery simulation model during the falling process;

[0022] Obtaining a displacement change threshold between each component in the battery simulation model;

[0023] The collision characterization amount of each component in the battery simulation model is determined according to the difference between the displacement change amount of each component and the displacement change threshold.

[0024] In one embodiment, determining the contact forces corresponding to the battery pack simulation model at multiple moments during the falling process includes:

[0025] Determine the penetration depth value corresponding to each moment of the falling process of the battery pack simulation model according to the relative positions of the contact point and the obstacle on the target contact surface at each moment of the falling process;

[0026] Obtaining a preset contact factor, where the preset contact factor is used to characterize the stiffness of the battery pack simulation model;

[0027] Determine the normal force corresponding to each moment of the battery pack simulation model during the falling process according to the preset contact factor and the penetration depth value corresponding to each moment of the battery pack simulation model during the falling process;

[0028] According to the normal force corresponding to the battery pack simulation model at each moment in the falling process, the contact force of the target contact surface at each moment in the falling process is determined.

[0029] In one of the embodiments, a friction coefficient between the preset battery pack simulation model and the obstacle is obtained;

[0030] Determine the friction force corresponding to each moment of the battery pack simulation model during the falling process according to the friction coefficient and the normal force corresponding to each moment of the battery pack simulation model during the falling process;

[0031] The friction force and the positive force corresponding to the battery pack simulation model at each moment in the falling process are processed by vector operation to obtain the contact force of the target contact surface at each moment in the falling process.

[0032] In one embodiment, determining the falling speed and falling angle of the battery pack simulation model when it falls onto the obstacle according to the contact forces corresponding to each of the multiple moments includes:

[0033] Generate a contact force curve according to the contact forces corresponding to the multiple moments, and determine an initial contact moment at which the contact force changes from the multiple moments according to the contact force curve, wherein the initial contact moment is the moment when the battery pack simulation model falls onto the obstacle;

[0034] Obtaining a drop speed change curve and a drop angle change curve of the battery pack simulation model during the drop process;

[0035] According to the initial contact moment, determining the falling speed of the battery pack simulation model when it falls onto the obstacle on the falling speed variation curve;

[0036] According to the initial contact moment, the drop angle of the battery pack simulation model when it falls onto the obstacle is determined in the drop angle variation curve.

[0037] In a second aspect, the present application also provides a battery pack drop simulation test device, comprising:

[0038] A monitoring module, used for monitoring the battery pack simulation model as it starts falling, wherein the battery pack simulation model includes a plurality of contact surfaces, each of which has a corresponding contact condition;

[0039] A first determination module is used to determine the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process when a trigger condition corresponding to a target contact surface among the multiple contact surfaces is detected to be triggered;

[0040] A second determination module is used to determine a falling speed and a falling angle of the battery pack simulation model when it falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0041] A generation module is used to generate a drop test result of the battery pack simulation model according to the drop speed and the drop angle.

[0042] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0043] Starting a falling process monitoring of a battery pack simulation model, the battery pack simulation model comprising a plurality of contact surfaces, each of the contact surfaces having a corresponding contact condition;

[0044] When it is monitored that a trigger condition corresponding to a target contact surface among the multiple contact surfaces is triggered, determining the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process;

[0045] Determining a falling speed and a falling angle of the battery pack simulation model when it falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0046] A drop test result of the battery pack simulation model is generated according to the drop speed and the drop angle.

[0047] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0048] Starting a falling process monitoring of a battery pack simulation model, the battery pack simulation model comprising a plurality of contact surfaces, each of the contact surfaces having a corresponding contact condition;

[0049] When it is monitored that a trigger condition corresponding to a target contact surface among the multiple contact surfaces is triggered, determining the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process;

[0050] Determining a falling speed and a falling angle of the battery pack simulation model when it falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0051] A drop test result of the battery pack simulation model is generated according to the drop speed and the drop angle.

[0052] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0053] Starting a falling process monitoring of a battery pack simulation model, the battery pack simulation model comprising a plurality of contact surfaces, each of the contact surfaces having a corresponding contact condition;

[0054] When it is monitored that a trigger condition corresponding to a target contact surface among the multiple contact surfaces is triggered, determining the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process;

[0055] Determining a falling speed and a falling angle of the battery pack simulation model when it falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0056] A drop test result of the battery pack simulation model is generated according to the drop speed and the drop angle.

[0057] The above-mentioned battery pack drop simulation test method, device, computer equipment, computer-readable storage medium and computer program product start the drop process monitoring of the battery pack simulation model, and the battery pack simulation model includes multiple contact surfaces, each of which has corresponding contact conditions; any contact points that may occur during the drop process can be captured to ensure that no important information is missed. When the trigger condition corresponding to the target contact surface among the multiple contact surfaces is detected to be triggered, the contact force corresponding to each of the multiple moments of the battery pack simulation model during the drop process is determined; which contact surfaces have produced actual contact and the magnitude of the contact force can be accurately identified, which is more accurate than relying solely on theoretical calculations. According to the contact forces corresponding to each of the multiple moments, the drop speed and drop angle of the battery pack simulation model when it falls to the obstacle are determined; the drop speed and angle are determined based on the change of the actual contact force. This method can better reflect the dynamic characteristics of the battery pack when it falls in the real world. Compared with the fixed assumptions of the drop speed and angle in the traditional method, the error introduced by the simplified model is reduced. According to the drop speed and the drop angle, the drop test result of the battery pack simulation model is generated. This makes the test results closer to the actual drop speed and angle, and its credibility and practicality will be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 A diagram showing an application environment of a battery pack drop simulation test method according to an embodiment;

[0060] Figure 2 It is a flowchart of a simulation test method for battery pack falling in one embodiment;

[0061] Figure 3 A schematic diagram of a battery pack falling simulation test method according to an embodiment;

[0062] Figure 4 is a schematic diagram of a falling speed variation curve in one embodiment;

[0063] Figure 5 is a schematic diagram of a drop angle variation curve in one embodiment;

[0064] Figure 6 is a flow chart of a simulation test method for battery pack drop in another embodiment;

[0065] Figure 7 It is a structural block diagram of a simulation test device for battery pack falling in one embodiment;

[0066] Figure 8 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0068] The battery pack drop simulation test method provided in the embodiment of the present application can be applied to Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The terminal 102 generates a simulation test request for the battery pack drop, and then sends the simulation test request for the battery pack drop to the server 104, so that the server 104 generates the drop test result of the battery pack simulation model. Among them, the terminal 102 can be, but is not limited to, various personal computers, laptops, smart phones, tablets, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car devices, projection devices, etc. Portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted device can be a virtual reality (VR) device, an augmented reality (AR) device, smart glasses, etc. The server 104 can be an independent physical server, a server cluster or a distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services.

[0069] In an exemplary embodiment, Figure 2 As shown, a battery pack drop simulation test method is provided, and the method is applied to Figure 1 The server 104 in the example is used as an example to illustrate, including the following steps 202 to 208. Among them:

[0070] Step 202 , starting to monitor the falling process of the battery pack simulation model, the battery pack simulation model includes a plurality of contact surfaces, each contact surface having a corresponding contact condition.

[0071] Among them, the battery pack simulation model refers to a virtual model built in multi-body dynamics software to simulate the behavior of a real battery pack during a fall. This model has been reasonably simplified to retain the main components of the battery pack, such as components, upper covers, side beams, cold plates, bottom reinforcement plates and other key components. Among them, components may be replaced by equivalent entities to improve the efficiency of the simulation. The creation of this model is based on the physical properties of the actual battery pack, such as geometric dimensions, mass, and inertia tensor, to ensure that it can accurately reflect the dynamic response of the real battery pack during a fall.

[0072] Contact surfaces refer to the surface areas where different components of the battery pack simulation model may come into contact with the external environment (usually the ground) or between different components inside the battery pack simulation model during a drop simulation. In this application, special attention is paid to the contact between the side beams, cold plates, bottom reinforcement plates and the ground. The definition of these contact surfaces is crucial for simulating collisions and contact forces during a drop, as they directly determine the forces on the battery pack when it comes into contact with the ground or other components.

[0073] Contact conditions refer to a series of rules and parameters set for contact surfaces in the simulation software to describe the behavioral characteristics of the interaction between contact surfaces. It can be understood that contact conditions can be set according to actual needs. Optionally, these conditions can be the type of contact (such as sliding contact, adhesive contact), friction coefficient, collision stiffness, collision damping, distance, etc. By setting the contact conditions, the interaction forces on the contact surface, including contact force and friction force, can be accurately calculated, thereby simulating the real collision effect. In the scenario of battery pack drop simulation, the setting of contact conditions helps to analyze the dynamic response of the battery pack simulation model when it contacts the ground, such as the size and distribution of the contact force, and the impact of this contact on the internal structure of the battery pack simulation model.

[0074] Specifically, the battery pack simulation model is first constructed in a multi-body dynamics software environment. By reasonably simplifying and retaining the core structure of the battery pack, such as components, upper cover, side beams, cold plate and bottom reinforcement plate, a virtual replica that can reflect the drop behavior of the real battery pack is formed. In order to improve the efficiency of the simulation, components may be replaced by equivalent entities, but overall, the creation of the model is strictly based on the physical properties of the actual battery pack, such as geometric dimensions, mass distribution and inertia tensor, to ensure that the dynamic response of the model during the drop process is highly consistent with the actual situation.

[0075] Then, during the monitoring process, focus on the contact behavior between different components of the battery pack simulation model and the external environment (especially the ground) or internal components during the fall. In this application, the contact between the side beams, cold plates, bottom reinforcement plates and the ground is particularly critical, because the definition of these contact surfaces directly affects the simulation accuracy of the collision and contact forces during the fall. By accurately defining the contact surface, the force conditions of the battery pack when it contacts the ground or other components can be more realistically simulated, which is crucial for evaluating the structural safety and performance of the battery pack.

[0076] Finally, in the simulation software, rules and parameters are specified for each contact surface, such as contact type (sliding or adhesion), friction coefficient, collision stiffness, collision damping, and contact distance. These parameters together determine the behavioral characteristics of the interaction between contact surfaces. By accurately setting these contact conditions, we can calculate the interaction forces on the contact surfaces, including contact forces and friction forces, and then simulate realistic collision effects. Especially in the scenario of battery pack drop simulation, the setting of contact conditions can not only help analyze the dynamic response of the battery pack simulation model when it contacts the ground, but also provide an in-depth understanding of the size and distribution of contact forces, and how these forces affect the integrity and stability of the internal structure of the battery pack simulation model.

[0077] Optionally, the battery pack simulation model is reasonably simplified, retaining the main key components, including components, upper cover, side beams, cold plate and bottom reinforcement plate, where the components are replaced by equivalent entities to obtain a streamlined battery pack simulation model to improve simulation efficiency. The three diagonal moments of inertia Ixx, Iyy and Izz of each component are determined by the 3D software (this moment of inertia is determined by the center of gravity of the component and aligned with the output coordinate system) so that it can be used as a parameter input in the multi-body dynamics software.

[0078] Import the streamlined battery pack simulation model into the multi-body dynamics simulation software, set the working environment (gravity direction, coordinate system type, unit, etc.), create a rigid body ground, define the material properties of each component of the battery pack simulation model (customize the mass and inertia tensor of each component to ensure that the streamlined battery pack simulation model is equivalent to the actual battery pack, including mass equivalence and center of gravity equivalence), set constraints (fix each component of the battery pack simulation model to each other, with the bolt connection hole position as the fixed position), set general contact, that is, contact surface (side beam, cold plate, bottom reinforcement plate and ground contact, so as to monitor the moment when the battery pack simulation model falls to the ground), create air resistance (determine the air resistance value, create a force field in the battery pack simulation model and apply force and torque in the X, Y, and Z directions), adjust the falling direction and falling height of the battery pack simulation model (the direction is that the positive and negative panels of the battery pack simulation model face the ground, the side beam falls vertically to the ground, and the height is the height specified by the test standard), create measurement (angle between the side beam and the ground, battery pack speed), adjust the step size and number of steps to start the battery pack drop simulation.

[0079] Step 204 , when it is monitored that the trigger condition corresponding to the target contact surface among the multiple contact surfaces is triggered, the contact forces corresponding to the battery pack simulation model at multiple moments during the falling process are determined.

[0080] The target contact surface refers to the surface where a specific part of the battery pack comes into direct physical contact with an external object (usually the ground) during a fall. These contact surfaces may be pre-defined, such as the contact surface between the side beam, cold plate, bottom reinforcement plate and the ground, which play a key role in the fall process because they are the first line of impact.

[0081] Contact force refers to the force that occurs on the target contact surface when the battery pack falls and contacts the ground or other objects. This force is generated by the collision and includes normal force (force perpendicular to the contact surface) and tangential force (force parallel to the contact surface, usually caused by friction). The magnitude and direction of the contact force are crucial to understanding the force state, stress distribution, and possible structural deformation or damage of the battery pack during the fall process.

[0082] Specifically, it is first necessary to clarify which parts are defined as target contact surfaces, such as side beams, cold plates, bottom reinforcement plates, etc. These parts are considered to be the areas most likely to contact the ground during a fall during the design phase. In order to automatically detect contact events during a fall, specific trigger conditions need to be set. This may include but is not limited to the distance between the contact surface and the ground reaching a certain threshold, or the change in acceleration or velocity exceeding a preset standard. These conditions help the system identify when and where contact occurs.

[0083] During the simulation, all predefined contact surfaces are continuously monitored to check whether the trigger conditions are met. Once contact is detected, the contact force on the contact surface is calculated immediately. This includes normal force (force perpendicular to the contact surface) and tangential force (force parallel to the contact surface). The contact force data at each time point is recorded for subsequent analysis.

[0084] Step 206 , determining the falling speed and falling angle of the battery pack simulation model when it falls onto the obstacle according to the contact forces corresponding to each of the multiple moments.

[0085] The obstacle refers to a real-world obstacle simulated in a simulation environment, and in this application, it specifically refers to the ground or other objects that may collide with the battery pack. It is a static reference in the drop simulation and is used to evaluate the contact force and structural response of the battery pack during the drop process.

[0086] Drop velocity refers to the speed of the battery pack at the moment it contacts an obstacle (such as the ground). It is an important indicator for measuring drop energy and impact strength. It includes velocity components in three dimensions (X, Y, and Z), reflecting the movement of the battery pack in different directions.

[0087] The drop angle refers to the posture of the battery pack at the moment of contact with the obstacle, specifically, the tilt angle of the battery pack relative to the ground. This parameter is crucial to understanding the force distribution and potential damage mode of the battery pack when it falls.

[0088] Specifically, refer to Figure 3 The simulation software continuously records the contact force data when the battery pack 301 contacts the obstacle 302 during the falling process. These data are collected at multiple time points to form a sequence of contact force changes over time.

[0089] After determining the moment of first contact, the software will go back to that moment and use simulation data to calculate the instantaneous velocity of the battery pack at the moment of contact. Considering that falling is a movement in three-dimensional space, the falling velocity includes velocity components in the three dimensions of X, Y, and Z, which fully reflects the movement state of the battery pack in all directions.

[0090] Similarly, using simulation data from the moment of first contact, the software can calculate the angle of inclination of the battery pack relative to the obstacle (usually the ground), i.e. the drop angle. This angle reveals the specific posture of the battery pack when it hits the ground, which is crucial for understanding the distribution of impact forces and predicting possible damage patterns.

[0091] Optionally, open the multi-body dynamics software post-processing and monitor the contact force curve of the battery pack simulation model. If the contact force suddenly increases from zero, it means that the battery pack simulation model is in contact with the ground and falls to the ground. Calibrate the angle and speed of the battery pack simulation model corresponding to the contact moment. The angle and speed are the required falling angle and falling speed of the battery pack simulation model when it falls to the obstacle.

[0092] Step 208, generating a drop test result of the battery pack simulation model according to the drop speed and the drop angle.

[0093] The drop test results include whether the maximum strain of the battery pack simulation model component exceeds the fracture elongation of the material, and whether there is overlap between components. If the strain of the battery pack simulation model component is lower than its fracture elongation, it means that the battery pack simulation model component will not break after falling; if there is no overlap between components, it means that there is no risk of external short circuit, thus avoiding possible fire or explosion accidents. These two points together prove that the structural design of the battery pack simulation model can meet the safety requirements of the drop test.

[0094] Specifically, after the battery pack drop finite element model is solved in the display dynamics calculation software, the drop test results obtained mainly include two key safety indicators: maximum strain and component overlap status.

[0095] In the finite element analysis, the software calculates the maximum strain values ​​of each battery pack component during the drop process. This value directly reflects the degree of deformation of the material when subjected to external loads. These maximum strain values ​​are compared with the elongation at break of the battery pack component materials. The elongation at break is the maximum amount of plastic deformation a material can withstand before breaking. If the maximum strain of all components is lower than the elongation at break of their materials, it can be inferred that these components will not break in the actual drop situation. This is because in the simulation, the material has not yet reached its failure limit.

[0096] The simulation results should also check the relative position changes between components inside the battery pack. Especially under the impact of a drop, abnormal contact or overlap may occur between components. Overlapping components may cause electrical short circuits, especially when battery cells are involved, which may lead to thermal runaway, fire or even explosion. If the simulation results show that there is no overlap between components during the drop process, that is, there is no direct physical contact that causes an electrical short circuit, this means that the battery pack is designed to effectively prevent the occurrence of such safety risks.

[0097] Optionally, import the battery pack simulation model into the finite element software, pre-process the model, establish the battery pack and ground mesh model (battery cells, end plates and beams are solid units, and other components are shell units), set up connections and contacts, assign material properties (add stress-strain curves to key components such as side beams, end plates, battery cell shells, cold plates, aluminum bars and upper covers, and set the ground as a rigid wall), set boundary conditions, input the drop angle and drop speed as initial conditions, place the battery pack close to the ground, check model interference, and export the battery pack drop finite element model.

[0098] Import the battery pack drop finite element model into the display dynamics calculation software, set the computer memory and core number, and start the solution calculation. After the calculation is completed, open the post-processing software to check whether the maximum strain of the battery cell shell exceeds the fracture elongation of its corresponding material and whether there is overlap between the components. If the strain is less than the fracture elongation, it means that the battery cell shell will not break. If there is no overlap between the components, there is no risk of external short circuit and no risk of fire and explosion, which proves that the battery pack structure is reasonable and meets the drop test requirements.

[0099] In one of the embodiments, the drop angular velocity of the battery pack simulation model is determined based on the drop speed and the drop angle; the distance between each contact point on the target contact surface and the center of mass of the battery pack simulation model is determined; and the deformation characterization quantity of the component to which the target contact surface belongs is determined based on the drop angular velocity and the distance between each contact point on the target contact surface and the center of mass of the battery pack simulation model.

[0100] Specifically, the known drop velocity and drop angle are first used as initial conditions, and the angular velocity during the drop process is calculated using the principle of dynamics. This usually involves a formula for converting linear velocity into angular velocity to obtain the drop angular velocity of the battery pack simulation model at a specific drop angle.

[0101] Then obtain the 3D geometry and structural layout of the battery pack simulation model, as well as the location information of the target contact surface. Determine the straight-line distance from each contact point on the target contact surface to the center of mass of the battery pack by geometric calculation or calling the built-in function of the finite element analysis software. Output a set of values ​​representing the distance from the center of mass to each contact point on the target contact surface.

[0102] Finally, mechanical formulas or finite element analysis software are used to calculate the deformation characterization of the component to which the target contact surface belongs during the drop process, combined with the drop angular velocity and the distance from the contact point to the center of mass. This may include but is not limited to parameters such as strain, stress, and displacement. The deformation characterization of the component to which the target contact surface belongs is obtained to evaluate the structural response and potential damage of the battery pack in the drop test.

[0103] The calculation of deformation characterization makes the safety assessment more comprehensive and specific. For example, it can reveal whether the battery pack has excessive strain or stress when it falls, thereby helping to identify potential failure points and ensuring that the product can maintain structural stability and functional safety when subjected to unexpected impacts.

[0104] In one of the embodiments, a preset density of a battery pack simulation model is obtained; the stress of each contact point on the target contact surface is determined based on the preset density, the drop angular velocity, and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model; and the deformation characterization quantity of the component to which the target contact surface belongs is determined based on the stress of each contact point on the target contact surface.

[0105] Specifically, firstly, the density parameters of each component are extracted or set from the data of the battery pack simulation model to obtain a detailed density distribution table, recording the density values ​​of each part of the battery pack. This usually needs to be based on the actual density values ​​of each material in the battery pack.

[0106] Then, the preset density of the battery pack simulation model, the drop angular velocity, and the distance from each contact point on the target contact surface to the center of mass of the battery pack are used as input data. The dynamics and stress analysis theory are combined with the finite element analysis method to calculate the stress of each contact point on the target contact surface during the drop process.

[0107] Finally, the stress of each contact point on the target contact surface is compared with the fracture stress threshold of the component where the target contact surface is located. The deformation characterization quantity of the component where the target contact surface is located is determined according to the comparison result. The deformation characterization quantity is used to determine the deformation degree of the component where the target contact surface is located in the battery pack simulation model. The deformation characterization quantity is a quantitative indicator reflecting the deformation degree of the component where the target contact surface is located in the battery pack simulation model.

[0108] In one embodiment, the stress of each contact point on the target contact surface is determined according to the preset density, the drop angular velocity, and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model, and is calculated by the following calculation formula:

[0109] Q=mw 2 (1-(d) 2 )

[0110] Wherein, m is the preset density, w is the drop angular velocity, d is the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model, and Q is the stress at each contact point on the target contact surface.

[0111] By incorporating the preset density, drop angular velocity, and distance from the contact point to the center of mass of the battery pack simulation model into the analysis, the stress distribution of each contact point and the deformation of the component during a drop event can be predicted more accurately. This predictive capability is crucial for understanding the response of the battery pack in complex environments.

[0112] In one embodiment, a drop test simulation is first run through finite element analysis software to collect and record the displacement change data of each component in the battery pack relative to other components during the drop process, thereby obtaining a detailed displacement change matrix containing the relative displacement changes of all components in the battery pack during the drop process.

[0113] Then a complete set of displacement change threshold tables is developed, covering the maximum allowable displacement changes of all component combinations in the battery pack. The displacement change threshold table determines the maximum allowable displacement change between each component in the battery pack, i.e. the displacement change threshold, based on material properties, component dimensions and design specifications. This usually involves a deep understanding of the physical properties and structural stability of each component in the battery pack.

[0114] Next, the actual displacement change of each component during the drop process is compared with the corresponding displacement change threshold. A list containing the comparison results of the displacement change of all component pairs and the displacement change threshold is obtained, and those component pairs whose displacement change exceeds the threshold are marked.

[0115] Finally, based on the displacement change that exceeds the displacement change threshold, the collision characterization of each component in the battery pack is calculated or evaluated. The collision characterization is used to indicate which components may have suffered severe collision and potential structural damage during the fall. The collision characterization is a quantitative indicator that reflects the degree of collision and structural damage suffered by each component in the battery pack.

[0116] By carefully tracking the displacement change of each component in the battery pack, the slight displacement change between components can be accurately captured, and the displacement change threshold defined by the design provides a clear safety boundary for the battery pack design to avoid unplanned contact or collision between components. By comparing the displacement change with the threshold, collision situations that may cause component damage or functional failure can be discovered in advance, so that necessary structural adjustments or material upgrades can be made during the design stage to improve the battery pack's drop resistance.

[0117] In one of the embodiments, the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process is determined according to the relative positions of the contact point and the obstacle on the target contact surface at each moment in the falling process; a preset contact factor is obtained, and the preset contact factor is used to characterize the stiffness of the battery pack simulation model; the normal force corresponding to the battery pack simulation model at each moment in the falling process is determined according to the preset contact factor and the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process; the contact force of the target contact surface at each moment in the falling process is determined according to the normal force corresponding to the battery pack simulation model at each moment in the falling process.

[0118] Specifically, the relative position changes of each contact point and the obstacle on the target contact surface when the battery pack contacts the obstacle are first recorded and analyzed during the simulation process, and a time-varying sequence of penetration depth values ​​is obtained, which reflects the degree of compression of the battery pack during the fall. Based on the material properties and design parameters of the battery pack simulation model, a contact factor is pre-set, which characterizes the stiffness of the battery pack, that is, the ability of the material to resist deformation.

[0119] Then, using the contact mechanics principle, combined with the preset contact factor and penetration depth value (penetration depth value is a quantitative indicator used to describe the degree of compression of the contact surface when the battery pack falls and contacts the ground or other obstacles), the normal force exerted on the battery pack at each moment during the fall is calculated. The normal force reflects the reaction force of the obstacle on the battery pack. Finally, a normal force sequence that changes with time is obtained, which represents the force applied to the battery pack during the fall.

[0120] Finally, the positive force sequence is analyzed and integrated to determine the contact force of the target contact surface at each moment during the fall, that is, the sum of the forces exerted by the obstacles on the battery pack. Finally, a detailed contact force time series is obtained, which reflects the changing trend of the contact force during the fall and can be used to evaluate the structural integrity and safety of the battery pack.

[0121] In one of the embodiments, according to the relative positions of the contact point and the obstacle on the target contact surface at each moment in the falling process, the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process is determined; a preset contact factor is obtained, and the preset contact factor is used to characterize the stiffness of the battery pack simulation model; according to the preset contact factor and the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process, the normal force corresponding to the battery pack simulation model at each moment in the falling process is determined, and is calculated by the following calculation formula:

[0122] Fz=K×g

[0123] Among them, K is the preset contact factor used to characterize the stiffness of the battery pack simulation model; g is the penetration depth value corresponding to a certain moment in the falling process of the battery pack simulation model; Fz is the normal force corresponding to a certain moment in the falling process of the battery pack simulation model.

[0124] By calculating the penetration depth and contact force during a drop in real time, it is possible to provide detailed information on the dynamic mechanical behavior of the battery pack as it interacts with the ground or other obstacles. This is critical to understanding the performance of the battery pack in real-world drop situations.

[0125] In one of the embodiments, the friction coefficient of a preset battery pack simulation model and an obstacle is obtained; the friction force corresponding to the battery pack simulation model at each moment in the falling process is determined based on the friction coefficient and the positive force corresponding to the battery pack simulation model at each moment in the falling process; the friction force and positive force corresponding to the battery pack simulation model at each moment in the falling process are vector-processed to obtain the contact force of the target contact surface at each moment in the falling process.

[0126] Specifically, first, the friction coefficient between the surface material of the battery pack simulation model and the contact surface of the obstacle is found or set. The friction coefficient is a physical quantity that measures the magnitude of the friction resistance between two contact surfaces.

[0127] Then, refer to the normal force data of the battery pack simulation model at each moment during the falling process obtained in the previous solution to confirm a normal force sequence that changes over time as the basis for calculating the friction force in the next step.

[0128] Next, the friction force calculation formula (friction force = friction coefficient × normal force) is used to calculate the friction force of the battery pack simulation model at each moment during the falling process. A friction force sequence that changes with time is obtained, which represents the friction resistance of the battery pack at different falling stages.

[0129] Finally, the friction force and the normal force at each moment are vector-added. Considering that the friction force is usually in the opposite direction to the normal force, a subtraction operation is actually performed on the same axis. A time-varying contact force sequence is obtained, which represents the total contact force borne by the target contact surface at each moment during the falling process.

[0130] By accurately calculating friction and normal force, it is possible to provide a detailed mechanical behavior simulation of the battery pack during the drop process, including the force conditions on the contact surface, which is crucial for understanding how the battery pack copes with different drop scenarios.

[0131] In one of the embodiments, a contact force curve is generated according to the contact forces corresponding to each of the multiple moments, and according to the contact force curve, an initial contact moment when the contact force changes is determined from the multiple moments, the initial contact moment being the moment when the battery pack simulation model falls to the obstacle; a drop speed change curve and a drop angle change curve of the battery pack simulation model during the falling process are obtained; according to the initial contact moment, the drop speed of the battery pack simulation model when it falls to the obstacle is determined from the drop speed change curve; according to the initial contact moment, the drop angle of the battery pack simulation model when it falls to the obstacle is determined from the drop angle change curve.

[0132] Specifically, first, during the entire falling process, record the contact force data when the battery pack contacts the ground or other obstacles. These data should cover all moments from the beginning to the end of the contact. Plot the recorded contact force data into a curve, with the horizontal axis representing time and the vertical axis representing the contact force.

[0133] Then the contact force curve is analyzed to find the point where the contact force changes significantly for the first time, which is the initial contact moment. The initial contact moment is the moment when the battery pack first contacts the obstacle. Figure 4 , extract the curve of falling speed changing with time from the simulation data, that is, the falling speed changing curve. Figure 5 , Similarly, a curve of the drop angle changing with time, namely the drop angle change curve, is extracted from the simulation data.

[0134] Finally, the initial contact moment is used as the time point to find the corresponding speed value on the drop speed change curve. Similarly, the corresponding drop angle value is found on the drop angle change curve.

[0135] In an exemplary embodiment, Figure 6 As shown, it includes steps 602 to 608. Among them:

[0136] Step 602, starting to monitor the falling process of the battery pack simulation model, the battery pack simulation model includes a plurality of contact surfaces, each contact surface has a corresponding contact condition;

[0137] Step 604, when it is monitored that the trigger condition corresponding to the target contact surface among multiple contact surfaces is triggered, determine the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process according to the relative positions of the contact point and the obstacle on the target contact surface at each moment in the falling process; obtain a preset contact factor, which is used to characterize the stiffness of the battery pack simulation model; determine the positive force corresponding to the battery pack simulation model at each moment in the falling process according to the preset contact factor and the penetration depth value corresponding to the battery pack simulation model at each moment in the falling process; obtain the preset friction coefficient of the battery pack simulation model and the obstacle; determine the friction force corresponding to the battery pack simulation model at each moment in the falling process according to the friction coefficient and the positive force corresponding to the battery pack simulation model at each moment in the falling process; perform vector operation processing on the friction force and positive force corresponding to the battery pack simulation model at each moment in the falling process to obtain the contact force of the target contact surface at each moment in the falling process;

[0138] Step 606, generating a contact force curve according to the contact forces corresponding to the multiple moments, and determining the initial contact moment when the contact force changes from the multiple moments according to the contact force curve, the initial contact moment being the moment when the battery pack simulation model falls to the obstacle; obtaining a falling speed change curve and a falling angle change curve of the battery pack simulation model during the falling process; determining the falling speed of the battery pack simulation model when it falls to the obstacle according to the initial contact moment, based on the falling speed change curve; determining the falling angle of the battery pack simulation model when it falls to the obstacle according to the initial contact moment, based on the falling angle change curve;

[0139] Step 608, determining the drop angular velocity of the battery pack simulation model according to the drop velocity and the drop angle; determining the distance between each contact point on the target contact surface and the center of mass of the battery pack simulation model; obtaining the preset density of the battery pack simulation model; determining the stress of each contact point on the target contact surface according to the preset density, the drop angular velocity, and the distance between each contact point on the target contact surface and the center of mass of the battery pack simulation model; determining the deformation characterization quantity of the component to which the target contact surface belongs based on the stress of each contact point on the target contact surface;

[0140] Alternatively, the displacement change between each component in the battery simulation model during the falling process is obtained; the displacement change threshold between each component in the battery simulation model is obtained; and the collision characterization value of each component in the battery simulation model is determined according to the difference between the displacement change between each component and the displacement change threshold.

[0141] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0142] Based on the same inventive concept, the embodiment of the present application also provides a battery pack drop simulation test device for implementing the battery pack drop simulation test method involved above. The implementation solution provided by the device is similar to the implementation solution recorded in the above method, so the specific limitations in one or more battery pack drop simulation test device embodiments provided below can refer to the limitations of the battery pack drop simulation test method above, and will not be repeated here.

[0143] In an exemplary embodiment, Figure 7 As shown, a battery pack drop simulation test device 700 is provided, including: a monitoring module 702, a first determination module 704, a second determination module 706 and a generation module 708, wherein:

[0144] A monitoring module 702 is used to monitor the battery pack simulation model starting to fall, where the battery pack simulation model includes multiple contact surfaces, each contact surface having a corresponding contact condition;

[0145] A first determination module 704 is used to determine the contact forces corresponding to the battery pack simulation model at multiple moments during the falling process when a trigger condition corresponding to a target contact surface among multiple contact surfaces is monitored to be triggered;

[0146] A second determination module 706, configured to determine a falling speed and a falling angle when the battery pack simulation model falls onto an obstacle according to the contact forces corresponding to each of the multiple moments;

[0147] The generation module 708 is used to generate the drop test result of the battery pack simulation model according to the drop speed and the drop angle.

[0148] Each module in the above-mentioned battery pack drop simulation test device can be implemented in whole or in part by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0149] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 8 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data related to the simulation test of the battery pack falling. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a simulation test method for battery pack falling is implemented.

[0150] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0151] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0152] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0153] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0154] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0155] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0156] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0157] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present 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 concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A battery pack drop simulation test method, characterized in that: The method comprises: Starting a falling process monitoring of a battery pack simulation model, the battery pack simulation model comprising a plurality of contact surfaces and a plurality of components, each of the contact surfaces having a corresponding contact condition, the contact condition comprising at least one of a contact type and a contact distance; When it is monitored that a trigger condition corresponding to a target contact surface among the multiple contact surfaces is triggered, determining the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process, wherein the trigger condition is a condition set for each contact condition for detecting the time and location of contact between the battery pack simulation model and the obstacle; Generate a contact force curve according to the contact forces corresponding to the multiple moments, and determine an initial contact moment at which the contact force changes from the multiple moments according to the contact force curve, wherein the initial contact moment is the moment when the battery pack simulation model falls onto the obstacle; Obtaining a drop speed change curve and a drop angle change curve of the battery pack simulation model during the drop process; According to the initial contact moment, determining the falling speed of the battery pack simulation model when it falls onto the obstacle on the falling speed variation curve; According to the initial contact moment, determining the drop angle of the battery pack simulation model when it falls onto the obstacle on the drop angle variation curve; According to the drop speed and the drop angle, the drop angular velocity of the battery pack simulation model is determined, and according to the drop angular velocity, the deformation characterization quantity of the component to which the target contact surface belongs included in the drop test result is determined.

2. The method according to claim 1, characterized in that The step of determining, according to the drop angular velocity, a deformation characterization quantity of a component to which the target contact surface belongs included in the drop test result, comprises: Determine the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model; The deformation characterization quantity of the component to which the target contact surface belongs is determined according to the falling angular velocity and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model.

3. The method according to claim 2, characterized in that The step of determining the deformation characterization quantity of the component to which the target contact surface belongs according to the drop angular velocity and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model includes: Obtaining a preset density of the battery pack simulation model; Determine the stress of each contact point on the target contact surface according to the preset density, the drop angular velocity, and the distance between each contact point on the target contact surface and the center of mass in the battery pack simulation model; The deformation characterization amount of the component to which the target contact surface belongs is determined based on the stress of each contact point on the target contact surface.

4. The method according to claim 1, characterized in that: The drop test results also include collision characterization quantities for each component; The method further comprises: Obtaining the displacement change between each component in the battery simulation model during the falling process; Obtaining a displacement change threshold between each component in the battery simulation model; The collision characterization amount of each component in the battery simulation model is determined according to the difference between the displacement change amount of each component and the displacement change threshold.

5. The method according to claim 1, characterized in that The determining of the contact forces corresponding to the battery pack simulation model at multiple moments during the falling process includes: Determine the penetration depth value corresponding to each moment of the falling process of the battery pack simulation model according to the relative positions of the contact point and the obstacle on the target contact surface at each moment of the falling process; Obtaining a preset contact factor, where the preset contact factor is used to characterize the stiffness of the battery pack simulation model; Determine the normal force corresponding to each moment of the battery pack simulation model during the falling process according to the preset contact factor and the penetration depth value corresponding to each moment of the battery pack simulation model during the falling process; According to the normal force corresponding to the battery pack simulation model at each moment in the falling process, the contact force of the target contact surface at each moment in the falling process is determined.

6. The method according to claim 5, characterized in that The determining the contact force of the target contact surface at each moment in the falling process according to the positive force corresponding to the battery pack simulation model at each moment in the falling process includes: Obtaining a preset friction coefficient of the battery pack simulation model and the obstacle; Determine the friction force corresponding to each moment of the battery pack simulation model during the falling process according to the friction coefficient and the normal force corresponding to each moment of the battery pack simulation model during the falling process; The friction force and the positive force corresponding to the battery pack simulation model at each moment in the falling process are processed by vector operation to obtain the contact force of the target contact surface at each moment in the falling process.

7. A battery pack drop simulation test device, characterized in that: The device comprises: A monitoring module, used for monitoring the battery pack simulation model starting to fall, wherein the battery pack simulation model includes a plurality of contact surfaces and a plurality of components, each of the contact surfaces having a corresponding contact condition, and the contact condition includes at least one of a contact type and a contact distance; A first determination module is configured to determine the contact forces corresponding to each of the battery pack simulation model at multiple moments during the falling process when a trigger condition corresponding to a target contact surface among the multiple contact surfaces is detected to be triggered, wherein the trigger condition is a condition set for each contact condition for detecting the time and location of contact between the battery pack simulation model and the obstacle; A second determination module is configured to generate a contact force curve according to the contact forces corresponding to the multiple moments, and to determine, according to the contact force curve, an initial contact moment at which the contact force changes from the multiple moments, wherein the initial contact moment is a moment when the battery pack simulation model falls onto an obstacle; Obtaining a drop speed change curve and a drop angle change curve of the battery pack simulation model during the drop process; According to the initial contact moment, determining the falling speed of the battery pack simulation model when it falls onto the obstacle on the falling speed variation curve; According to the initial contact moment, determining the drop angle of the battery pack simulation model when it falls onto the obstacle on the drop angle variation curve; A generation module is used to determine the drop angular velocity of the battery pack simulation model according to the drop velocity and the drop angle, and determine the deformation characterization quantity of the component to which the target contact surface belongs included in the drop test result according to the drop angular velocity.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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