Kinematic parameter output method and device, storage medium and electronic product

Abstract

The invention provides a kinematics parameter output method and device, a storage medium and an electronic product. The method comprises the steps that a digital human body finite element model is established; constructing an output component composed of grid units; respectively configuring output components in a femoral condyle area and a tibial plateau area, and associating a main node with a shared node of a motion control area by calculating the displacement of the main node; defining kinematics parameters related to a knee joint injury mechanism by taking finite element node displacement of a kinematics output area as a calculation basis; finite element feature point coordinates before and after collision are obtained through finite element simulation, and kinematics parameters are obtained through calculation. The method has the advantages that parameters related to knee joint injury are focused, the limitation that a traditional method only depends on macroscopic indexes is broken through, targeted support is provided for injury mechanism analysis and injury degree prediction, and vehicle structure optimization and pedestrian protection development are assisted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of traffic safety, and particularly relates to a method, device, storage medium and electronic product for outputting kinematics parameters of lower limbs of a digital human body model in a collision condition. BACKGROUND

[0002] In the development of automobile collision safety, computer simulation technology has become an important support means. The digital human body model, with excellent biological fidelity, gradually replaces the traditional physical dummy and becomes a key tool for vehicle passive safety research, especially in pedestrian protection development.

[0003] However, the current mainstream simulation platform has significant defects in the output of lower limb kinematics parameters. Firstly, the existing methods focus on macroscopic indicators such as overall acceleration and collision force, and lack accurate analysis of parameters such as knee joint bending angle, ligament deformation, and knee joint relative sliding, which are strongly associated with lower limb injury risk. Secondly, related indicators are difficult to integrate in the same module, and output data needs to be processed and measured in different post-processing software, resulting in low work efficiency.

[0004] Therefore, there is an urgent need for a motion data output method based on local fine modeling of lower limbs to accurately capture the kinematic response of lower limbs during the collision process, and to provide support for injury mechanism analysis, injury degree prediction, and vehicle structure optimization. SUMMARY

[0005] To solve the above technical problems, the application provides a kinematics parameter output method, which is particularly suitable for representing the kinematic response of the lower limbs of a digital human body model in a pedestrian collision accident through a finite element model.

[0006] The technical solution adopted by the application is as follows: in the first aspect, a kinematics parameter output method is provided, comprising the following steps: establishing a digital human finite element model; constructing an output component composed of grid elements, the output component including a motion control area, an interval area, an acceleration output area and a kinematics output area integrated by shared nodes, and the finite element nodes connected by shared nodes are shared nodes; configuring the output component in the femoral condyle region and the tibial plateau region of the digital human finite element model, selecting a plurality of finite element nodes of the surface grid elements in the femoral condyle region and the tibial plateau region to form a node set, obtaining the displacement of the main node by calculating the average displacement of all finite element nodes in the node set, and directly associating the main node with the shared node of the motion control area; defining kinematics parameters related to knee joint injury based on the spatial coordinates of the finite element nodes of the kinematics output area; A plurality of finite element characteristic points are selected on the outer surface of the kinematics output area, and the coordinates of the finite element characteristic points before and after the collision are obtained through finite element simulation, and the kinematics parameters are calculated.

[0007] Further, the kinematics parameters include the overall displacement of the knee joint, the rotation angle between the femur and the tibia, the relative sliding between the femur and the tibia, the valgus angle of the knee joint, the relative rotation angle between the femur and the tibia, and the spatial motion trajectory of the knee joint.

[0008] Further, the motion control area is used to uniformly receive the average displacement of the bone section and transmit it to the interval area; and the interval area is used to isolate the acceleration output area, the motion control area and the kinematics output area.

[0009] Further, the acceleration output area is made of rigid material, and the motion control area, the interval area and the kinematics output area are made of linear elastic material.

[0010] Further, the density of the rigid material and the linear elastic material is set to 1×10 -10 kg / mm³~1×10 -8 kg / mm³; the elastic modulus of the linear elastic material is set to 15000Mpa~25000Mpa, and the Poisson's ratio is set to 0.28~0.32.

[0011] Further, the kinematics output area selects at least three non-collinear finite element characteristic points, and the finite element characteristic points in the femoral condyle area and the tibial plateau area are aligned along the motion direction of the knee joint.

[0012] Further, the valgus angle of the knee joint is represented by the included angle of the vector formed in the coronal plane of the knee joint based on the coordinates of the finite element characteristic points after the collision.

[0013] In a second aspect, an electronic device is provided, including at least one processor, and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the kinematics parameter output method provided by the present disclosure.

[0014] In a third aspect, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to enable a computer to perform the kinematics parameter output method provided by the present disclosure.

[0015] In a fourth aspect, a computer program product is provided, including computer programs / instructions, and the computer programs / instructions are used to enable a processor to perform the kinematics parameter output method provided by the present disclosure.

[0016] The application has the advantages and positive effects that: due to the above technical scheme, a multi-region integrated output assembly is constructed, seamless connection is realized through a common node connection, a unified data output format is realized, the python program can be directly called, multiple post-processing software is not needed, the operation complexity is greatly reduced, and the data processing efficiency is improved; the main node is directly associated with the motion control region shared node, uniform and accurate transmission of the bone displacement to the entire assembly is ensured, and reliable data basis is provided for kinematic parameter calculation; the parameters related to the knee joint injury mechanism are focused on, the limitation of traditional methods relying on only macroscopic indicators is broken through, targeted support is provided for injury mechanism analysis and injury degree prediction, and help is provided for vehicle structure optimization and pedestrian protection development; the material parameters are set to a reasonable range, the needs of different collision simulation scenarios are covered, and the universality and adaptability of the technical scheme are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a flowchart of a kinematic parameter output method of an embodiment of the application; Figure 2 is a structural schematic diagram of an output assembly of an embodiment of the application; Figure 3 is a position schematic diagram of an output assembly of an embodiment of the application on a lower limb skeleton; Figure 4 is a schematic diagram of an output assembly of an embodiment of the application before and after the knee joint is bent; Figure 5 is a schematic diagram of an output assembly of an embodiment of the application in which the femur and the tibia produce relative sliding; Figure 6 is a schematic diagram of an output assembly of an embodiment of the application in which the knee joint produces eversion; Figure 7 is a schematic diagram of an output assembly of an embodiment of the application in which the femur and the tibia produce relative rotation in the knee joint; In the figure: output assembly 100; femoral condyle region 200; tibial plateau region 300; motion control region 10; interval region 20; acceleration output region 30; kinematic output region 40. DETAILED DESCRIPTION

[0018] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which example embodiments of the present disclosure are described. The technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present disclosure.

[0019] As Figure 1As shown, the present application provides a kinematic parameter output method, comprising the following steps: S100, a digital human finite element model is established; Specifically, the finite element model of the digital human model is constructed independently, or an open-source digital human model scheme is adjusted, and the digital human model at least includes a lower limb part, so as to ensure that the model can accurately restore the physiological motion characteristics and mechanical response of the lower limb in the collision process and meet the accuracy requirements of the collision simulation.

[0020] S200, an output assembly composed of grid elements is constructed, the output assembly includes a motion control area, a spacing area, an acceleration output area and a kinematic output area integrated by a common node method, and the finite element nodes connected by the common node are shared nodes; Specifically, the output assembly is built by selecting a hexahedral grid element (finite element), and the output assembly integrates the motion control area, the spacing area, the acceleration output area and the kinematic output area four functional areas, and all the boundary nodes of the contact surface of each adjacent area are shared by using the common node connection method, that is, the shared nodes.

[0021] S300, the output assembly is respectively configured in the femoral condyle area and the tibial plateau area of the digital human finite element model, a plurality of finite element nodes of the surface grid elements in the femoral condyle area and the tibial plateau area are selected to form a node set, the displacement of the main node is obtained by calculating the average displacement of all the finite element nodes in the node set, and the main node is directly associated with the shared nodes of the motion control area; Specifically, the output assembly is respectively fixed and installed at the lower end of the femoral condyle area and the upper end of the tibial plateau area of the digital human model, at least three finite element nodes of the surface grid elements in the femoral condyle area are selected to form a first node set, and at least three finite element nodes of the surface grid elements in the tibial plateau area are selected to form a second node set; the average displacement of all the finite element nodes in the first node set and the second node set is calculated by interpolation or arithmetic average method to obtain the first main node displacement and the second main node displacement; the first main node is directly associated with all the shared nodes of the motion control area and the spacing area of the output assembly arranged at the lower end of the femoral condyle area by the common node, and the second main node is directly associated with all the shared nodes of the motion control area and the spacing area of the output assembly arranged at the upper end of the tibial plateau area by the common node, so that the motion control area can synchronize the average displacement of the bone section.

[0022] S400, the spatial coordinates of the finite element nodes of the kinematic output area (the displacement of the finite element node is calculated by the spatial coordinates of the finite element node before and after the collision simulation) are taken as the calculation basis to define the kinematic parameters related to the knee joint injury mechanism; S500: Select several finite element feature points on the exposed surface outside the kinematic output area, simulate a car collision scenario through finite element simulation, obtain the coordinates of the three-dimensional finite element feature points before and after the collision, and obtain the kinematic parameters through preset logic calculation.

[0023] Using the above method, a multi-region integrated output component is constructed. Seamless connection is achieved through shared nodes, and a unified data output format is implemented. This allows for direct calls by Python programs, eliminating the need for multiple post-processing software, significantly reducing operational complexity and improving data processing efficiency. By directly linking the main node with the shared nodes of the motion control area, uniform and accurate transmission of bone displacement to the entire component is ensured, providing a reliable data foundation for kinematic parameter calculations. Focusing on parameters related to knee joint injury mechanisms, this approach overcomes the limitations of traditional methods that rely solely on macroscopic indicators, providing targeted support for injury mechanism analysis and injury severity prediction, and contributing to vehicle structure optimization and pedestrian protection development.

[0024] In one embodiment, the kinematic parameters include overall knee joint displacement, rotation angle between the femur and tibia, relative sliding between the femur and tibia, valgus angle of the knee joint, relative rotation angle between the femur and tibia, and spatial motion trajectory of the knee joint.

[0025] Specifically, the overall displacement of the knee joint characterizes the degree of overall movement of the knee joint in space after the collision, and is calculated based on the coordinate changes of corresponding feature points on the femoral and tibial sides; the rotation angle between the femur and tibia reflects the change in the relative flexion and extension angles of the femur and tibia before and after the collision, and is determined by the angle difference between the vectors formed by the feature points before and after the collision; the relative slippage between the femur and tibia characterizes the relative sliding amplitude of the femur and tibia within the knee joint, and is a key indicator for judging the degree of injury; the valgus angle of the knee joint reflects the degree of abnormal deformation in the coronal plane of the knee joint after the collision, which conforms to the clinical injury assessment criteria; the relative rotation angle between the femur and tibia captures the relative torsional motion of the knee joint in the coronal plane, reflecting the abnormal rotational state of the joint; the spatial motion trajectory of the knee joint is fully reconstructed by using the midpoint coordinates of the feature points and the average coordinates of all feature points to fully reconstruct the spatial motion path of the knee joint during the collision.

[0026] To address the issues of ambiguous functional positioning in different regions, uneven motion transmission, and attribute conflicts arising from direct contact between rigid and flexible regions, this embodiment provides an implementation method.

[0027] In one embodiment, the motion control area is used to uniformly receive the average displacement of the bone cross section and transmit it to the interval area; the interval area is used to isolate the acceleration output area, the motion control area and the kinematic output area, physically separating the rigid acceleration output area from the flexible motion control area and kinematic output area, avoiding node attribute conflicts caused by direct contact between areas with different attributes, and ensuring that each area functions independently and works collaboratively.

[0028] By adopting the above method, the core function of receiving and transmitting average displacement in the motion control area is clearly defined, ensuring that the skeletal movement is accurately synchronized to the output component, and avoiding displacement transmission distortion from affecting the accuracy of parameter calculation. By isolating different functional areas through the interval area, simulation conflicts caused by direct contact between rigid and flexible areas are effectively avoided, ensuring a stable and smooth simulation process. The clear division of regional functions provides a clear basis for subsequent material selection and parameter setting, improving the feasibility and implementability of the entire technical solution.

[0029] In one embodiment, the acceleration output area is made of rigid material to adapt to the installation requirements of the acceleration acquisition device and ensure that the macroscopic acceleration index can be accurately captured; the motion control area, the interval area and the kinematic output area are made of linear elastic material so that each area can move synchronously with the skeleton during the collision process while maintaining structural stability.

[0030] In one embodiment, the densities of the rigid material and the linear elastic material are set to 1 × 10⁻⁶. -10 kg / mm³~1×10 - 8 kg / mm³; the elastic modulus of the linear elastic material is set to 15000 MPa to 25000 MPa, and the Poisson's ratio is set to 0.28 to 0.32.

[0031] Preferably, the density of the rigid material and the linear elastic material is set to 1×10⁻⁶. -9 The elastic modulus of the linear elastic material was set to 21000 MPa and the Poisson's ratio was set to 0.3.

[0032] Using the above method, material parameters are set within a reasonable range to cover the needs of different collision simulation scenarios, improving the versatility and adaptability of the technical solution; the lightweight density range design avoids the interference of the output component's own weight on the movement of the digital human body model, ensuring that the simulation process closely matches the real collision situation; the range of elastic modulus and Poisson's ratio adapts to the balance requirements of displacement transmission and deformation control, ensuring accurate motion transmission while avoiding excessive component deformation from affecting the measurement results, thus taking into account both the accuracy of parameter calculation and the stability of simulation.

[0033] In one embodiment, at least three non-collinear finite element feature points are selected in the kinematic output region, and the finite element feature points in the femoral condyle region and the tibial plateau region are aligned along the direction of knee joint movement.

[0034] In one embodiment, the knee valgus angle is represented by the angle between vectors formed in the coronal plane of the knee joint based on the coordinates of the finite element feature points after the collision.

[0035] The following description, in conjunction with a preferred embodiment, illustrates the content involved in the above embodiments.

[0036] likeFigure 2 As shown, the output component is constructed using hexahedral mesh elements, forming a 6×6 tiled square structure with a total of 36 mesh elements. The output component includes a motion control area 10, a spacing area 20, an acceleration output area 30, and a kinematic output area 40. All boundary nodes on the contact surfaces of adjacent areas are shared using a common node connection method. The mesh element arrangement within each area is as follows: Figure 2 As shown, the acceleration output region 30 is made of rigid material, while the motion control region 10, the interval region 20, and the kinematic output region 40 are made of linear elastic material. The density of the rigid material and the linear elastic material is set to 1×10⁻⁶. -9 The elastic modulus of the linear elastic material was set to 21000 MPa and the Poisson's ratio was set to 0.3.

[0037] like Figure 3 As shown, two identical output components 100 are fixedly positioned at the lower end of the femoral condyle region 200 and the upper end of the tibial plateau region 300 of the digital human body model, respectively. The finite element elements of the motion control area are closely fitted with the mesh elements of the bone surface. Ten finite element nodes are uniformly selected from the surface mesh elements of the femoral condyle region 200 to form a first node set; ten finite element nodes are uniformly selected from the surface mesh elements of the tibial plateau region 300 to form a second node set. The selected finite element nodes are all distributed on the contact surface between the bone and the motion control area. This is achieved through equations... Calculate the displacements of the first and second master nodes. The displacements of the first and second master nodes in the x, y, and z directions are equal to the sum of the displacements of all finite element nodes within the node set in the corresponding directions, divided by the number of nodes. Directly associate the master nodes with all shared nodes adjacent to the motion control zone and the interval zone.

[0038] like Figures 4-7 As shown, three non-collinear pre-collision finite element feature points are selected on the outer surface of the kinematic output area of ​​the femoral condyle region output component, denoted as... , , On the outer surface of the kinematic output area of ​​the output component in the tibial plateau region, three non-collinear pre-collision finite element feature points are selected, denoted as... , , ,in and , and , and Align them one by one along the direction of knee flexion and extension. to These are denoted as finite element feature points after the collision. A side-impact collision scenario is simulated using finite element simulation software, and the three-dimensional coordinates of all finite element feature points before the collision are recorded. Three-dimensional coordinates of all finite element feature points after the collision Overall displacement of the knee joint The specific calculation equation is as follows: ; rotation angle between femur and tibia The specific calculation equation is as follows: , ; ; relative slippage between the femur and tibia The specific calculation equation is as follows: ; After a collision, severe damage to the knee joint can lead to valgus (outward displacement of the knee). The specific calculation equation is as follows: ; When the knee joint is severely damaged, relative rotation can occur between the femur and tibia. The angle of relative rotation between the femur and tibia... The specific calculation equation is as follows: ; Pick and The spatial motion trajectory of the knee joint can be obtained by finding the midpoint of the midpoint.

[0039] Based on embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0040] An electronic device includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the kinematic parameter output method provided in this disclosure.

[0041] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0042] A non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the kinematic parameter output method provided in this disclosure.

[0043] The various embodiments of this disclosure can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0044] A computer program product includes a computer program / instructions, which, when executed by a processor, provide a method for outputting kinematic parameters.

[0045] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0046] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0047] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for outputting kinematic parameters, characterized in that, Includes the following steps: Establish a digital finite element model of the human body; An output component composed of mesh elements is constructed. The output component includes a motion control area, a gap area, an acceleration output area, and a kinematic output area integrated through a common node method. The finite element nodes connected through the common node are shared nodes. The output components are respectively configured in the femoral condyle region and the tibial plateau region of the digital human finite element model. Several finite element nodes of the surface mesh elements in the femoral condyle region and the tibial plateau region are selected to form a node set. The displacement of the master node is obtained by calculating the average displacement of all finite element nodes in the node set. The master node is directly associated with the shared node of the motion control area. Based on the spatial coordinates of the finite element nodes in the kinematic output region, kinematic parameters related to knee joint injury are defined. Several finite element feature points are selected on the outer surface of the kinematic output region. The coordinates of the finite element feature points before and after the collision are obtained through finite element simulation, and the kinematic parameters are calculated.

2. The kinematic parameter output method according to claim 1, characterized in that: The kinematic parameters include the overall displacement of the knee joint, the rotation angle between the femur and tibia, the relative slippage between the femur and tibia, the valgus angle of the knee joint, the relative rotation angle between the femur and tibia, and the spatial motion trajectory of the knee joint.

3. The kinematic parameter output method according to claim 1, characterized in that: The motion control zone is used to uniformly receive the average displacement of the bone cross section and transmit it to the interval zone; the interval zone is used to isolate the acceleration output zone, the motion control zone and the kinematic output zone.

4. The kinematic parameter output method according to claim 3, characterized in that: The acceleration output region is made of rigid material, and the motion control region, the interval region, and the kinematic output region are made of linear elastic material.

5. The kinematic parameter output method according to claim 4, characterized in that: The density of the rigid material and the linear elastic material is set to 1×10⁻⁶. -10 kg / mm³~1×10 -8 kg / mm³; the elastic modulus of the linear elastic material is set to 15000 MPa to 25000 MPa, and the Poisson's ratio is set to 0.28 to 0.

32.

6. The kinematic parameter output method according to claim 2, characterized in that: The kinematic output region selects at least three non-collinear finite element feature points, and the finite element feature points set in the femoral condyle region and the tibial plateau region are aligned along the direction of knee joint movement.

7. The kinematic parameter output method according to claim 6, characterized in that: The valgus angle of the knee joint is represented by the angle between vectors formed by the coordinates of the finite element feature points after the collision within the coronal plane of the knee joint.

8. An electronic device, comprising: At least one processor; as well as A memory that is communicatively connected to at least one processor; wherein, The memory stores instructions that can be executed by at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium storing computer instructions, wherein, Computer instructions are used to cause a computer to perform the method according to any one of claims 1 to 7.

10. A computer program product comprising a computer program / instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 7.

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