THUMS dummy adjusting method based on BOUNDARY command

Abstract

The invention relates to the technical field of collision safety, in particular to a THUMS dummy adjusting method based on a BOUNDARY command. Comprising the steps that simulation software is installed, a THUMS human body model is obtained, and meanwhile an original model file is backed up; entering a simulation environment, importing a THUMS human body model, and ensuring that the initial posture of the adjusted model meets an expected collision scene or experiment requirement; determining a target posture of the THUMS human body model, including analyzing a key part of the target posture and determining the position of the key part, and editing the model to set the target posture; dummy simulation parameters are set, an Orient command is used for moving a THUMS model part to a target position, a BOUNDARY command is used for defining a target posture of a THUMS human body model and inputting a recovery curve, and meanwhile a simulation step length and a time step length are set; attitude adjustment simulation is executed, and attitude changes in the simulation process are observed; and replacing the adjusted THUMS model node information with the node information in the original model. According to the technical scheme, the efficiency and accuracy of a simulation experiment can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of collision safety, and in particular to a THUMS dummy adjustment method based on a BOUNDARY command. Background Art

[0002] In the field of collision safety research, accurate simulation and analysis of human body injuries and movements in various collision scenarios are of vital importance for vehicle design, safety device development, and injury biomechanics research. To achieve this goal, human models, as key tools, play a core role in simulating dynamic responses and injury mechanisms in collision events. As one of the most advanced human models currently available, the THUMS (Total Human Model for Safety) model has become the tool of choice in the fields of vehicle collision simulation, safety protection device design, and bone and soft tissue injury analysis due to its high bio-fidelity and detailed anatomical structure.

[0003] However, despite the significant progress made in the biomechanical properties of the THUMS model, in practical applications, the matching degree between the initial posture of the model and the real collision scene is still a key factor affecting the accuracy of the simulation results. Traditional posture adjustment methods usually rely on applying a gravity field or manual operation to adjust the posture of the model. These methods are not only time-consuming but also inefficient, and it is difficult to meet the high-precision and high-efficiency requirements of complex collision scenarios for model posture adjustment.

[0004] Specifically, the traditional gravity field adjustment method simulates the influence of the earth's gravity on the model and gradually adjusts the model to a posture close to the target. However, this method is not only slow in adjustment, but also difficult to accurately control the posture change of the model, especially when dealing with complex postures or when multiple postures need to be adjusted quickly. In addition, although manual operation provides higher flexibility to a certain extent, it also has the problems of being cumbersome, error-prone and difficult to repeat, which is not conducive to large-scale simulation experiments and rapid iterative design. Summary of the invention

[0005] The purpose of the present invention is to propose a THUMS dummy adjustment method based on BOUNDARY command, and the technical solution can improve the efficiency and accuracy of simulation experiments.

[0006] To achieve the above objectives, the present disclosure provides a THUMS dummy adjustment method based on a BOUNDARY command, comprising: Install LS-DYNA simulation software, obtain THUMS human body model, and back up the original model file; Enter the simulation environment, import the THUMS human model, and ensure that the initial posture of the adjusted THUMS human model meets the expected collision scenario or experimental requirements; Determining a target posture of the THUMS model, including analyzing key parts of the target posture and determining their precise positions, and editing the THUMS model to set the target posture; Set the simulation parameters of the dummy, use the Orient command to move the THUMS model to the target position, use the BOUNDARY command to define the target posture of the THUMS human body model and input the recovery curve, and set the appropriate simulation step and time step; Perform posture adjustment simulation, observe the posture changes of the THUMS human model during the simulation, and check whether the final posture of the THUMS human model is consistent with the expected target after the simulation; Replace the adjusted THUMS model node information with the node information in the original model.

[0007] Beneficial effects of the basic solution: posture adjustment with high degrees of freedom and high flexibility. Through the Orient command, specific parts of the THUMS human model can be moved to the specified position. Subsequently, the node information of these target positions can be remembered using the BOUNDARY command, thereby achieving free adjustment of the posture. This adjustment method also has a wide range of applicability. On the one hand, the model can be edited to set a variety of target postures to adapt to a variety of simulation scenarios and test requirements. On the other hand, it can also be widely used in the posture adjustment of other human models or multi-rigid body systems, greatly improving the flexibility and application scope of posture adjustment.

[0008] By defining the recovery curve in the BOUNDARY command and leveraging the powerful geometry processing capabilities of LS-DYNA, high-precision posture adjustment can be achieved in the simulation. This high-precision control ensures that the final posture is highly consistent with the expected target, thereby improving the reliability of the simulation results.

[0009] By setting reasonable parameters, such as optimizing the simulation step and time step, the simulation time can be significantly reduced while maintaining the accuracy of the simulation results. By backing up the original model file, accidental damage can be prevented during the adjustment process, improving the reliability of the model adjustment of this solution. Compared with traditional methods, the adjustment process can be more efficient, and even if the model is damaged, it can be restored in time through backup.

[0010] After adjusting the THUMS model pose, replacing the adjusted node information with the node information in the original model can ensure that the model maintains consistent physical properties during simulation. This helps avoid physical property inconsistencies caused by model adjustments, thereby improving the reliability of simulation results.

[0011] Traditional methods usually adjust the posture of the THUMS dummy by applying a gravity field, which is time-consuming and inefficient. However, the present invention can significantly shorten the posture adjustment time and improve the efficiency of simulation preparation by using the Orient and BOUNDARY commands.

[0012] Since the time and labor cost of manual operation are reduced, the present invention shows a more obvious efficiency advantage when processing multiple posture adjustments or complex postures.

[0013] As an implementable preferred solution, the key parts of the target posture include the head, torso, and limbs.

[0014] As an implementable preferred solution, the target posture is edited and set by extracting the coordinate information of the target posture from actual data or manually inputting the coordinate information.

[0015] As an implementable preferred solution, use the Orient command to move the THUMS model part to the target position, including the following: Use the Orient command to select the part of the THUMS model that needs to be moved, enter the coordinate information of the target position, and move the dummy to the target position; Set geometric constraints on the THUMS model and make the non-moving parts of the dummy rigid.

[0016] As an implementable preferred solution, a recovery curve is input to control the moving speed of the dummy part, including the following: By adjusting the time and completion parameters in the recovery curve, the movement speed of the dummy part from the initial position to the target position is controlled.

[0017] As an implementable preferred solution, setting a suitable simulation step size and time step size includes the following: Return to the Orient command interface to return the dummy parts to their initial positions. Set different movement steps and time steps for each part of the THUMS human body model. For parts that require fine adjustment, set smaller movement steps and time steps.

[0018] As an implementable preferred solution, if the final posture of the THUMS human body model deviates from the expected target, the recovery curve is adjusted or the target posture is reset, and the simulation is performed again; during the re-simulation, if the dummy reports an error or a negative volume problem occurs in some meshes, check whether irregular mesh deformation occurs inside the model.

[0019] As an implementable preferred solution, if the mesh is found to be deformed, the strength of that part can be strengthened during adjustment, such as adding constraints or adjusting the mesh division method, or changing one adjustment to multiple adjustments to reduce the problem of mesh errors due to large pulling. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a logic diagram of a THUMS dummy adjustment method based on the BOUNDARY command.

[0021] Figure 2 Schematic diagram of posture adjustment in this embodiment. DETAILED DESCRIPTION

[0022] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only partial embodiments of the present invention, which are only used to explain the present application, rather than to limit the present application. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered isolated, and they can be combined with each other to achieve better technical effects. The same reference numerals appearing in the drawings of the following embodiments represent the same features or components, which can be applied to different embodiments.

[0023] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should have the common meanings understood by those skilled in the art in the art to which the present invention belongs.

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings: Reference Figure 1 , a THUMS dummy adjustment method based on BOUNDARY command, comprising: Step S100, install the simulation software. In this embodiment, install LS-DUNA simulation software (an explicit finite element analysis software used in the engineering field, mainly used to simulate complex nonlinear dynamic problems), which supports the BOUNDAR command (mainly used to create polylines or polygonal boundaries of closed areas). Obtain the original file of the THUMS human body model to ensure that its format is compatible with the simulation software; back up the original model file to prevent accidental damage during the adjustment process.

[0025] Step S200, enter the simulation environment, import the original file of the THUMS human model, observe and adjust the initial posture of the THUMS human model after importing, and compare it with the expected collision scene or experimental requirements to ensure that the initial posture meets the requirements.

[0026] Step S300, determining the target posture of the THUMS model, includes: Step S301, according to the specific collision scenario or experimental requirements, analyze the target posture that the THUMS model needs to present in the simulation, determine the key parts of the target posture, such as the head, torso, limbs, etc., and clarify their precise positions.

[0027] Step S302, edit the THUMS model and set the target posture. Extract the coordinate information of the target posture (coordinates of each main part) from the actual data and import it, or manually input the coordinate information to ensure that the setting of the target posture meets the standards in the field of ergonomics and collision safety.

[0028] In one embodiment, a target posture library containing a variety of common collision scenarios is established to facilitate users to quickly select and apply.

[0029] Step S400, setting dummy simulation parameters, includes: Step S401, refer to Figure 2 , use the Orient command (mainly used to rotate, align or reposition an object), select the part of the THUMS model that needs to be moved (such as an arm or leg), enter the coordinate information of the target position, and move the dummy to the target position (the green position).

[0030] Set geometric constraints on the THUMS model and make the immovable parts of the dummy rigid to ensure that the immovable parts remain fixed during the posture adjustment process, thereby improving the accuracy of the adjustment. For example, when adjusting the movement of the upper body, change the lower body Part to a rigid body, specifically by changing the mat (material type) of the Part to No. 20, and at the same time set the degrees of freedom of the part to prohibit rotation and translation, specifically by setting the CON1 field and CON2 field in the mat card to 7.

[0031] Step S402, use the BOUNDARY_PRESCRIBED_FINAL_GEOMETRY command to define the target posture of the THUMS human model, and input the recovery curve (corresponding to time and completion). By adjusting the time and completion parameters in the recovery curve, the movement speed of the dummy parts is controlled. The recovery curve is used to control the movement speed of the dummy parts from the initial position to the target position. For example, if the palm is moved to the position of the steering wheel, the distance is long, so the time must be longer. Specifically, in the recovery curve, the time when the completion degree is 1 must be longer. Otherwise, the time is too short, which will cause the mesh of the dummy to be severely deformed, resulting in the inability to perform secondary operations. The normal time is generally 40ms. When the distance is large, the completion time can be appropriately extended.

[0032] Step S403, return to the Orient command interface, return the dummy part to the initial position (red position), ensure that all boundary conditions and initial conditions are correctly set, set appropriate simulation step and time step, and for parts that need fine adjustment, set smaller movement step and time step to improve the accuracy of posture adjustment. Specifically, it is determined according to the quality of the mesh after posture adjustment. In one embodiment, the initial time can be selected as 30ms, replace the adjusted node information, and determine whether the dummy mesh has a large deformation or negative volume has appeared. If so, increase the time.

[0033] In one embodiment, an automated verification tool is used, the detection area of ​​the automated verification tool is configured, and the collected initial posture data is analyzed and evaluated. The posture angles of various parts are calculated, the differences with the standard posture are compared, and whether the initial posture conforms to the ergonomic principles is evaluated.

[0034] Step S500, performing posture adjustment simulation, includes: Step S501, start the simulation, observe the posture changes of the THUMS human model during the simulation process, refer to Figure 2 , ensuring that the dummy parts move from the initial position (red position) to the target position (green position) as expected.

[0035] Step S502, after the simulation is completed, check whether the final posture of the THUMS human body model is consistent with the expected target. If there is a deviation, adjust the recovery curve or reset the target posture, and simulate again. During the simulation again, if there is a problem such as a dummy error or negative volume in some meshes, check whether irregular mesh deformation occurs inside the model.

[0036] If you find that the mesh is deformed, you can strengthen the strength of that part during adjustment, such as adding constraints or adjusting the mesh division method, or changing one adjustment to multiple adjustments to reduce the problem of errors caused by large mesh pulling.

[0037] Step S600, replacing the node information of the adjusted THUMS model with the node information in the original model, to ensure that the adjusted model maintains a consistent network structure and physical properties during subsequent use.

[0038] The above contents are only embodiments of the present invention. The common sense such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or the priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before the date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A THUMS dummy adjustment method based on BOUNDARY command, characterized in that: include: Install LS-DYNA simulation software, obtain THUMS human body model, and back up the original model file; Enter the simulation environment, import the THUMS human model, and ensure that the initial posture of the adjusted THUMS human model meets the expected collision scenario or experimental requirements; Determining a target posture of the THUMS model, including analyzing key parts of the target posture and determining their precise positions, and editing the THUMS model to set the target posture; Set the simulation parameters of the dummy, use the Orient command to move the THUMS model to the target position, use the BOUNDARY command to define the target posture of the THUMS human body model and input the recovery curve, and set the appropriate simulation step and time step; Perform posture adjustment simulation, observe the posture changes of the THUMS human model during the simulation, and check whether the final posture of the THUMS human model is consistent with the expected target after the simulation; Replace the adjusted THUMS model node information with the node information in the original model.

2. A THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: The key parts of the target posture include the head, torso, and limbs.

3. The THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: The target posture is edited and set by extracting the coordinate information of the target posture from the actual data or manually inputting the coordinate information.

4. The THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: Use the Orient command to move the THUMS model parts to the target location, including the following: Use the Orient command to select the part of the THUMS model that needs to be moved, enter the coordinate information of the target position, and move the dummy to the target position; Set geometric constraints on the THUMS model and make the non-moving parts of the dummy rigid.

5. The THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: Enter the recovery curve to control the movement speed of the dummy parts. Includes the following: By adjusting the time and completion parameters in the recovery curve, the movement speed of the dummy part from the initial position to the target position is controlled.

6. The THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: Set appropriate simulation step size and time step, including the following: Return to the Orient command interface to return the dummy parts to their initial positions. Set different movement steps and time steps for each part of the THUMS human body model. For parts that require fine adjustment, set smaller movement steps and time steps.

7. The THUMS dummy adjustment method based on BOUNDARY command according to claim 1, characterized in that: If the final posture of the THUMS human model deviates from the expected target, adjust the recovery curve or reset the target posture and simulate again. When simulating again, if the dummy reports an error or some meshes have negative volume problems, check whether irregular mesh deformation occurs inside the model.

8. The THUMS dummy adjustment method based on BOUNDARY command according to claim 7, characterized in that: If the mesh is found to be deformed, strengthen the strength of that part during adjustment, such as adding constraints or adjusting the mesh division method, or changing one adjustment to multiple adjustments to reduce the problem of errors caused by large pulling of the mesh.

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