Automobile H point and H point suitable line intelligent design method

Abstract

The application discloses an intelligent design method for automobile H point and H point suitable line, characterized by taking AHP point as a fixed input parameter, taking H30, A47 and human body percentile as variable parameters, taking BOFRP point coordinate value and H point X value as intermediate parameters, taking H point suitable line of H point and different percentiles (2.5, 5, 10, 50, 90, 95, 97.5 percentiles) of human body as output parameters, and based on secondary development function of CATIA software, a knowledge engineering template file capable of directly displaying a design target structure is established; the template is called during design, different H30, A47 or human body percentile parameters are input according to design requirements, the knowledge engineering template is automatically run and the calculated output parameters are directly displayed in the form of graphics. The application has the advantages of better simplifying a calculation process, reducing errors caused by repeated calculation, and better improving design efficiency and accuracy.

Description

Technical Field

[0001] This invention relates to the field of automotive vehicle design technology, specifically to an intelligent design method for the H-point and suitable H-point line of an automobile. Background Technology

[0002] The H-point (H-Point) in vehicle design refers to the intersection of the driver's thigh line and torso line, equivalent to the hip joint in a human body; hence, it is also called the hip point or buttock point. In overall vehicle design, the H-point coincides with the seat reference point (SgRP point or R point) and can be used as a vehicle reference point. The vehicle design standard SAE J 1517 Driver Selected Seat Position specifies the driver's seat position for Class A vehicles (passenger cars, vans, light trucks) and Class B vehicles (heavy trucks, buses, multi-purpose trucks). The standard also describes the calculation methods for the H-point corresponding to different anthropometric percentiles, such as the 2.5 percentile, 5 percentile, 10 percentile, 50 percentile, 90 percentile, 95 percentile, and 97.5 percentile. Connecting all H-points corresponding to the same anthropometric percentile yields the H-point alignment line. The H-point is one of the most critical hard points in automotive ergonomics design. All components and shapes of the vehicle body (human position, pedal position, steering wheel position, control panel position, instrument panel, buttons, etc.) must be designed with the driver's H-point as the reference point. Therefore, the H-point and its suitable line are a very important and unavoidable part of automotive ergonomics design.

[0003] In the early stages of automotive design, the H-point needs to be calculated and defined (the 50th and 95th percentiles are most commonly used) as a benchmark for the overall vehicle's ergonomics design. While the H-point is crucial, it cannot be finalized all at once. As the styling design changes and the plans of various related disciplines become more detailed, the H-point often needs to be adjusted accordingly (generally by ergonomics designers, reflected in the overall layout hard point diagram).

[0004] The standard calculation steps for the traditional H-point and the suitable line for the H-point are as follows. (See appendix for terminology used in the calculation process.) Figure 1 I understand. (Attached) Figure 1 Point 1 is the AHP point, which is located in the same position as the HOS point during design; point 2 is the H point, which is located in the same position as the SgRP point or R point during design; point 3 is the BOFRP point, which is located in the same position as the BOF point during design; points 4-10 are suitable lines for H points at different percentiles.

[0005] (1) Make the AHP point; the AHP point (Accelerator Heel Point) is the contact point between the sole of the shoe model of the H point device and the unpressed accelerator pedal surface when the ankle angle is 87°, and the contact point between the heel and the floor surface.

[0006] (2) Create the BOFRP point; the BOFRP point (Ball of Foot Reference Point) is a vehicle reference point that is consistent with the position of the driver's BOF point. The BOF point (Ball of Foot) is a point 203mm away from the HOS point (heel point) from the center of the side of the shoe model. The HOS point is consistent with the AHP point in the design.

[0007] Based on the AHP point and the value of A47 (defined in standard SAE J 1100 as the angle between the driver's shoe plane and the horizontal plane; the value of A47 depends on the specific vehicle model), the BOFRP point is constructed. The distance between the BOFRP point and the AHP point is 203mm, and the angle with the horizontal is A47.

[0008] (3) According to the calculation standard, calculate the H-point X value corresponding to different percentiles using the formula specified in the known standard SAE J 1517 3.1. The H-point Z value is the seat height H30 (the H30 value range for Class A vehicles is 127mm-405mm, and the H30 value here is determined according to the specific vehicle model requirements) minus the Z-direction height difference between the BOFRP point and the AHP point, and the Y value is 0mm. Using the BOFRP point as a reference point, construct the H-point using the three-coordinate method based on the calculated H-point X, Y, and Z values.

[0009] (4) Make a suitable line for point H.

[0010] Based on the AHP points obtained in step (1) and the A47 value in step (2), multiple H points of different percentile human bodies are made and fitted into lines respectively, so as to obtain the appropriate H point line of the corresponding percentile human body.

[0011] For example, taking the 97.5 percentile human body as an example, H30 is divided into groups of 5 mm from 127 mm to 405 mm, and H points are calculated for each group, resulting in 6 H points for the 97.5 percentile. These 6 H points are then fitted into a curve to obtain the suitable H point line for the 97.5 percentile. The suitable H point lines for other percentile human bodies are calculated using the same method, and the corresponding H points are fitted to obtain suitable H point lines from the 2.5 percentile to the 97.5 percentile.

[0012] As can be seen from the above calculation process, the traditional method of creating suitable H-point lines is cumbersome and involves many steps. Each adjustment requires consulting the relevant calculation formulas in the standard (SAE J 1517), considering how to redefine certain initial calculation parameters, and then recalculating to obtain the corresponding H-points. For designers, memorizing the calculation process and applying it proficiently is time-consuming and prone to errors. Furthermore, the calculations are based on assumed AHP points; once the AHP points change, all H-points need to be recalculated, which greatly reduces design efficiency and easily leads to calculation errors.

[0013] Therefore, for those skilled in the art, it is crucial to obtain the corresponding H-point more accurately and quickly during the early stages of vehicle styling design, when data changes frequently. This can greatly improve design efficiency and accuracy. However, existing design methods do not include intelligent design methods for the H-point. Summary of the Invention

[0014] To address the shortcomings of the existing technologies, the technical problem this invention aims to solve is: how to provide an intelligent design method for the H-point and suitable H-point line of a vehicle that can better simplify the calculation process and reduce errors caused by repeated calculations, thereby improving design efficiency and accuracy.

[0015] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0016] A method for intelligent design of the H-point and suitable H-point line for automobiles, characterized by the following steps:

[0017] Step A: Based on the secondary development function of CATIA software, create a knowledge engineering template file (part file) that can intuitively display the design target structure. Use AHP points as fixed input parameters, H30, A47, and human percentiles as variable input parameters, BOFRP point coordinates and H-point X-values ​​as intermediate parameters, and H-point and suitable H-point lines for different percentiles (2.5, 5, 10, 50, 90, 95, 97.5 percentiles) as output parameters. Establish the correspondence between input parameters, intermediate parameters, and output parameters in the knowledge engineering template file and implement automatic conversion and association; obtain an intelligent design template for H-points and suitable H-point lines.

[0018] Step B: In CATIA software, set up an environment for calling the intelligent design template of H-point and H-point suitable line. Call the intelligent design template of H-point and H-point suitable line established in step A. Input different H30, A47 or human percentile parameters according to design needs. The knowledge engineering template will run automatically and display the calculated output parameters in a graphical way.

[0019] This method utilizes the secondary development capabilities of CATIA software to pre-define the correspondence between input and output parameters in a knowledge engineering template file, establishing a corresponding model. During design, only the input parameters to be adjusted need to be entered, and the model automatically calculates and outputs the corresponding H-points and suitable H-point line graphs. Designers can quickly adjust the input parameters and instantly obtain changes in the H-points and suitable H-point line graphs to determine the rationality of the design. Specifically, in this invention, the AHP point is used as a fixed input parameter because this method is primarily applicable to the early stages of vehicle design, when the positions of important components (such as the accelerator pedal) are initially determined, but the styling design is not yet finalized, and the overall layout ergonomics is in a period of change. At this stage, since the AHP point is the first reference point for the ergonomics design, it is a confirmed value that does not need further modification. However, the values ​​of H30, A47, and human percentiles may be repeatedly adjusted during this stage due to changes in the styling or project requirements, thus serving as variable input parameters. Then, appropriate intermediate parameters are selected to streamline the calculation process. The correspondence between input parameters, intermediate parameters, and output parameters is determined based on the geometric conversion relationships and conversion formulas specified by design standards, enabling automatic conversion and association. This allows designers to quickly change variable parameter input information and see different calculation results simply by calling a preset engineering template file. This simplifies the calculation process, reduces errors caused by repeated calculations, and significantly improves design efficiency and accuracy.

[0020] Furthermore, step A specifically includes the following steps:

[0021] 1. Open CATIA software and establish a coordinate system. Based on the known AHP point values, establish AHP points in the coordinate system and use them as design reference points. The coordinate system is a horizontal rectangular coordinate system. The X-axis is set along the length of the vehicle, the Y-axis is set along the width of the vehicle, and the Z-axis is set along the height of the vehicle.

[0022] 2. In the coordinate system, establish and assign values ​​to the variable parameters to be input according to the parameter definitions. The variable parameters include H30, A47 and human percentile.

[0023] Where: H30 is the seat height, which is also the vertical distance from point H to point AHP; when creating the template model, H30 is first arbitrarily selected from the range of values;

[0024] A47 is the angle between the driver's shoe plane and the horizontal plane, that is, the angle between the driver's accelerator pedal and the horizontal plane when the driver presses the accelerator pedal (as defined in standard SAE J 1100). When creating the template, A47 is first arbitrarily selected from the range of values.

[0025] Anthropometric percentile is a term used in anthropometrics to characterize the distribution of human body dimensions. Anthropometric percentile represents the percentage of people with a certain human body size or smaller than that size out of the total number of people in the statistics. (For example, the 5th percentile, or human height, means that 5% of people have a height equal to or smaller than that size.) When creating a template, the anthropometric percentile is first arbitrarily selected from the range of values.

[0026] 3. Establish and assign the X value of the intermediate parameter H point in the coordinate system. This value is the X coordinate value of the desired output result H point, which is calculated according to the following formulas (1)-(7).

[0027] X 97.5=936.6+0.613879z-0.00186247z 2 (1)

[0028] X 95=913.7+0.672316z-0.00195530z 2 (2)

[0029] X 90=885.0+0.735374z-0.00201650z 2 (3)

[0030] X 50=793.7+0.903387z-0.00225518z 2 (4)

[0031] X 10=715.9+0.968793z-0.00228674z 2 (5)

[0032] X 5 = 692.6 + 0.981427z - 0.00226230z 2 (6)

[0033] X 2.5=687.1+0.895336z-0.00210494z 2 (7)

[0034] In formulas (1)-(7), X 97.5 represents the H-point X value corresponding to the 97.5 percentile in the human body; X 95 represents the X value at point H corresponding to the 95th percentile of the human body; X 90 represents the X value at point H corresponding to the 90th percentile of the human body; X 50 represents the H-point X value corresponding to the 50th percentile in the human body; X10 represents the X value at point H corresponding to the 10th percentile in the human body; X 5 represents the H-point X value corresponding to the 5th percentile in the human body; X 2.5 represents the H-point X value corresponding to the 2.5th percentile of the human body; z represents the H-point Z value corresponding to the same percentile of the human body, i.e., the value of H30;

[0035] Establish the correspondence between the H-point X value and different human percentiles and H30 values ​​according to formulas (1)-(7) (the calculation formula comes from the standard SAE J 1517).

[0036] 4. Using the AHP point as the design reference point, obtain the intermediate parameter BOFRP point coordinate value, and make the BOFRP point. The correspondence between the BOFRP point, the AHP point, and A47 is that the distance between the BOFRP point and the AHP point is 203mm, and the angle between the line connecting the BOFRP point and the AHP point and the X-axis is the value of parameter A47.

[0037] 5. Create point H. Establish point H in the form of a three-coordinate system, with the BOFRP point as the reference point. The correspondence between the three-coordinate values ​​of point H and the intermediate parameters is as follows:

[0038] X value = H point X;

[0039] Y value = 0 mm;

[0040] Z-value = H30 - (Z-axis elevation difference between BOFRP point and AHP point);

[0041] 6. Using the "Insert - Knowledge Engineering Template - User Features" command, create an H-point calculation process template from steps 1 to 5 above and save it (save it as a part file), and include the corresponding relationships of each parameter in the template;

[0042] 7. Using the AHP points as the input conditions in step 1 as a reference, repeatedly call the H-point calculation template obtained in step 6, calling it 42 times, with each group consisting of 6 calls. Each time, modify the human percentile to different groups (2.5, 5, 10, 50, 90, 95, 97.5, a total of seven groups), and modify H30 to different values ​​(H30 is divided into groups of 5 mm from 127 mm to 405 mm). This yields 6 H-points for different H30 parameters corresponding to different groups of human percentiles. Fit the 6 H-points of each group into a curve to obtain the suitable H-point line for different groups of percentiles; this suitable line changes with the AHP points.

[0043] 8. Using the "Insert - Knowledge Engineering Template - User Features" command, create an intelligent design template for H-point and H-point suitable line based on the process in steps 1 to 7 above, and supplement it (save it as a part file) for subsequent template calls.

[0044] By employing the above steps, the conversion relationships between fixed input parameters, variable parameters, intermediate parameters, and output parameters—defined based on geometric shapes and those specified by design standards—can be quickly solidified into the knowledge engineering template module of CATIA software. The selection of intermediate parameters simplifies and enhances the reliability of this conversion process. Once the conversion relationships are solidified, designers can directly call the template, modify the variable parameters to obtain the output parameters, and utilize the software's built-in display function to obtain a clear structural view of the output parameters, facilitating parameter adjustment and selection during the design process.

[0045] Furthermore, in step 2, the range of H30 values ​​is limited according to standard requirements, so that a prompt is displayed when the input exceeds the range. This is because the standard SAE J 1100 specifies the dimensions of H30; for example, the H30 value range for Category A vehicles is 127mm-405mm. Therefore, directly limiting the value range in the program module and displaying a prompt when the value exceeds the range can better avoid design errors.

[0046] Furthermore, in step 2, the value of A47 is limited, and a prompt is displayed if the input exceeds the 0-90° range. This is because in actual design process, the value of A47 is unlikely to exceed the 0-90° range. Therefore, displaying a prompt when the value exceeds the range in the program module can better prevent design errors.

[0047] Furthermore, in steps 2 and 7, the range of human percentile values ​​is limited to 2.5, 5, 10, 50, 90, 95, or 97.5. This is because the standard SAE J 1517 specifies the calculation formulas for H30 to H-point X corresponding to these human percentiles: 2.5, 5, 10, 50, 90, 95, and 97.5. Therefore, human percentiles within this range can directly establish the operational relationship between the input parameters and intermediate parameters according to the standard, facilitating subsequent calculations.

[0048] Furthermore, in step 7, when modifying the value of H30, the modification is performed in groups of 5 mm from 127 mm to 405 mm. This makes the calculation more uniform and the fitted H-point line more accurate.

[0049] Further, step B includes the following steps:

[0050] 9. Open CATIA software. On the toolbar, use the "Insert - Instantiate from Selection" command to switch to the created "H-point and H-point suitable line intelligent design template" part file. Select the "H-point and H-point suitable line intelligent design template" directory tree. According to the window prompts, match the AHP points to be designed with the AHP points in the "H-point and H-point suitable line intelligent design template". After confirming that there are no errors, end the call.

[0051] 10. The "Intelligent Design Template for H Point and H Point Suitable Line" application structure tree is generated on the directory tree of the part files created in step 9. The H point, BOFRP point, and H point suitable lines of 2.5, 5, 10, 50, 90, 95, and 97.5 appear in the 3D data window. Open the structure tree and modify the parameters "H30", "A47", and "human percentile" to meet the requirements of the new vehicle model project. The H point will then be updated accordingly, that is, the corresponding H point and H point suitable line will be displayed synchronously.

[0052] Therefore, this design eliminates the need to consult tables and formulas, or repeatedly calculate based on trigonometric relationships. Users can simply call the model and change the values ​​of the variable parameters to obtain the values ​​of the corresponding H-point and its suitable line, visually displaying their position and structural changes. This significantly improves design efficiency and accuracy.

[0053] Therefore, this invention first organizes the design inputs for the H-point and its suitable line template. The intermediate modeling process is managed through parameters and geometric constraints. The calculations and design rules involved are implemented by embedding calculation formulas and establishing rules using VB conditional statements to drive automatic updates of the geometric model. Finally, the intermediate modeling process is packaged and encapsulated to form an intelligent design template for the H-point and its suitable line. All devices with this feature can then be designed by calling the template. By pre-defining input conditions and designing input values, the entire feature can be adaptively updated to form a product model that meets engineering design requirements. Therefore, compared with existing technologies, the parametric design of the H-point eliminates the need for repetitive product modeling during product design; only a limited number of parameters need to be changed to obtain the corresponding results, greatly shortening the design time. Furthermore, the application results can be automatically updated as the input conditions change, avoiding repetitive work.

[0054] In summary, this invention has the advantages of simplifying the calculation process, reducing errors caused by repeated calculations, and improving design efficiency and accuracy. Attached Figure Description

[0055] Figure 1 This is a schematic diagram illustrating the position of each parameter display location in the present invention. Detailed Implementation

[0056] The present invention will now be described in further detail with reference to specific embodiments.

[0057] Figure 1 This invention relates to a schematic diagram of the display positions of various parameters. The meanings of the labels in the diagram are as follows: 1 - AHP point (same as HOS point), 2 - H point (also known as SgRP point, R point), 3 - BOFRP point (same as BOF point), 4 - 2.5 percentile human fitness line, 5 - 5 percentile human fitness line, 6 - 10 percentile human fitness line, 7 - 50 percentile human fitness line, 8 - 90 percentile human fitness line, 9 - 95 percentile human fitness line, 10 - 97.5 percentile human fitness line.

[0058] The technical terms involved in this invention are explained as follows:

[0059] Three-dimensional coordinate system: According to Article 5 of SAE J 1100, the coordinate system in automotive 3D design is divided into three axes: X-axis, Y-axis, and Z-axis. The X-axis is from the front to the rear of the vehicle, the Y-axis is from the left to the right of the vehicle, and the Z-axis is from the bottom to the top of the vehicle.

[0060] Anthropometric percentile: A term used in anthropometrics to determine the distribution of human body dimensions. A percentile represents the percentage of people with a particular body size or smaller than that size in a statistical study. For example, the 5th percentile (5th percentile for height) means that 5% of people are equal to or smaller than that height.

[0061] HOS (Heel Point): Defined in SAE J 1100, section 3.5.8, it is the lowest and last point on the lateral center plane of the shoe model. When correctly placed on a pressure floor, it defines the position of the driver's AHP (Awake Point) and the occupant's FRP (Fixed Surface Mount Point). The design should coincide with the AHP point.

[0062] AHP point: Accelerator Heel Point. As defined in SAE J 1100, section 3.5.1, it refers to the heel point on the unpressurized floor where the shoe model fixing device of the H-point device contacts the unpressurized accelerator pedal when the ankle angle is 87°. It usually coincides with the HOS point.

[0063] BOF point: Ball of Foot, defined in SAE J 1100 3.5.2 as: a point 203mm from the HOS point at the center of the side of the shoe model.

[0064] BOFRP (Ball of Foot Reference Point): A vehicle reference point that corresponds to the driver's BOF point position as specified in clause 3.5.3 of standard SAE J 1100. Its position applies only to the driver's position.

[0065] H-point: According to standard SAE J 1100 3.4.5 or SAE J826, the H-point is the intersection of the thigh line and the torso line. In the overall vehicle design, the H-point coincides with the SgRP point and can be used as a vehicle reference point.

[0066] SgRP (R point): Seating Reference Point. As specified in SAE J 1100 3.4.8, the SgRP is a reference point defined early in the vehicle design process and is of paramount importance to the driver. It is used to locate various tools and defines many critical dimensions, serving as a benchmark in domestic and international standards and regulations. During design, its location coincides with the H point.

[0067] H30: Seat height, specified in standard SAE J 1100, usually refers to the vertical distance from the SgRP point to the AHP point.

[0068] A47: Defined in SAE J 1100 as the angle between the driver's shoe plane and the horizontal plane. Detailed implementation method:

[0070] A method for intelligent design of the H-point and suitable H-point line for automobiles, characterized by the following steps:

[0071] Step A: Based on the secondary development function of CATIA software, create a knowledge engineering template file (part file) that can intuitively display the design target structure. Use AHP points as fixed input parameters, H30, A47, and human percentiles as variable input parameters, BOFRP point coordinates and H-point X-values ​​as intermediate parameters, and H-point and suitable H-point lines for different percentiles (2.5, 5, 10, 50, 90, 95, 97.5 percentiles) as output parameters. Establish the correspondence between input parameters, intermediate parameters, and output parameters in the knowledge engineering template file and implement automatic conversion and association; obtain an intelligent design template for H-points and suitable H-point lines.

[0072] Step B: In CATIA software, set up an environment for calling the intelligent design template of H-point and H-point suitable line. Call the intelligent design template of H-point and H-point suitable line established in step A. Input different H30, A47 or human percentile parameters according to design needs. The knowledge engineering template will run automatically and display the calculated output parameters in a graphical way.

[0073] This method utilizes the secondary development capabilities of CATIA software to pre-define the correspondence between input and output parameters in a knowledge engineering template file, establishing a corresponding model. During design, only the input parameters to be adjusted need to be entered, and the model automatically calculates and outputs the corresponding H-points and suitable H-point line graphs. Designers can quickly adjust the input parameters and instantly obtain changes in the H-points and suitable H-point line graphs to determine the rationality of the design. Specifically, in this solution, the AHP point is used as a fixed input parameter because this method is primarily applicable to the early stages of vehicle design, when the positions of important components (such as the accelerator pedal) are initially determined, but the styling design is not yet finalized, and the overall layout ergonomics is in a period of change. At this stage, since the AHP point is the first reference point for the ergonomics design, it is a confirmed value that does not need further modification. However, the values ​​of H30, A47, and human percentiles may be repeatedly adjusted during this stage due to changes in styling or project requirements, thus serving as variable input parameters. Then, appropriate intermediate parameters are selected to streamline the calculation process. The correspondence between input parameters, intermediate parameters, and output parameters is determined based on the geometric conversion relationships and conversion formulas specified by design standards, enabling automatic conversion and association. This allows designers to quickly change variable parameter input information and see different calculation results simply by calling a preset engineering template file. This simplifies the calculation process, reduces errors caused by repeated calculations, and significantly improves design efficiency and accuracy.

[0074] In practice, step A specifically includes the following steps:

[0075] 1. Open CATIA software and establish a coordinate system. Based on the known AHP point values, establish AHP points in the coordinate system and use them as design reference points. The coordinate system is a horizontal rectangular coordinate system. The X-axis is set along the length of the vehicle, the Y-axis is set along the width of the vehicle, and the Z-axis is set along the height of the vehicle.

[0076] 2. In the coordinate system, establish and assign values ​​to the variable parameters to be input according to the parameter definitions. The variable parameters include H30, A47 and human percentile.

[0077] Where: H30 is the seat height, which is also the vertical distance from point H to point AHP; when creating the template model, H30 is first arbitrarily selected from the range of values;

[0078] A47 is the angle between the driver's shoe plane and the horizontal plane, that is, the angle between the driver's accelerator pedal and the horizontal plane when the driver presses the accelerator pedal (as defined in standard SAE J 1100). When creating the template, A47 is first arbitrarily selected from the range of values.

[0079] Anthropometric percentile is a term used in anthropometrics to characterize the distribution of human body dimensions. Anthropometric percentile represents the percentage of people with a certain human body size or smaller than that size out of the total number of people in the statistics. (For example, the 5th percentile, or human height, means that 5% of people have a height equal to or smaller than that size.) When creating a template, the anthropometric percentile is first arbitrarily selected from the range of values.

[0080] 3. Establish and assign the X value of the intermediate parameter H point in the coordinate system. This value is the X coordinate value of the desired output result H point, which is calculated according to the following formulas (1)-(7).

[0081] X 97.5=936.6+0.613879z-0.00186247z 2 (1)

[0082] X 95=913.7+0.672316z-0.00195530z 2 (2)

[0083] X 90=885.0+0.735374z-0.00201650z 2 (3)

[0084] X 50=793.7+0.903387z-0.00225518z 2 (4)

[0085] X 10=715.9+0.968793z-0.00228674z 2 (5)

[0086] X 5 = 692.6 + 0.981427z - 0.00226230z 2 (6)

[0087] X 2.5=687.1+0.895336z-0.00210494z 2 (7)

[0088] In formulas (1)-(7), X 97.5 represents the H-point X value corresponding to the 97.5 percentile in the human body; X 95 represents the X value at point H corresponding to the 95th percentile of the human body; X 90 represents the X value at point H corresponding to the 90th percentile of the human body; X 50 represents the H-point X value corresponding to the 50th percentile in the human body; X10 represents the X value at point H corresponding to the 10th percentile in the human body; X 5 represents the H-point X value corresponding to the 5th percentile in the human body; X 2.5 represents the H-point X value corresponding to the 2.5th percentile of the human body; z represents the H-point Z value corresponding to the same percentile of the human body, i.e., the value of H30;

[0089] Establish the correspondence between the H-point X value and different human percentiles and H30 values ​​according to formulas (1)-(7) (the calculation formula comes from the standard SAE J 1517).

[0090] 4. Using the AHP point as the design reference point, obtain the intermediate parameter BOFRP point coordinate value, and make the BOFRP point. The correspondence between the BOFRP point, the AHP point, and A47 is that the distance between the BOFRP point and the AHP point is 203mm, and the angle between the line connecting the BOFRP point and the AHP point and the X-axis is the value of parameter A47.

[0091] 5. Create point H. Establish point H in the form of a three-coordinate system, with the BOFRP point as the reference point. The correspondence between the three-coordinate values ​​of point H and the intermediate parameters is as follows:

[0092] X value = H point X;

[0093] Y value = 0 mm;

[0094] Z-value = H30 - (Z-axis elevation difference between BOFRP point and AHP point);

[0095] 6. Using the "Insert - Knowledge Engineering Template - User Features" command, create an H-point calculation process template from steps 1 to 5 above and save it (save it as a part file), and include the corresponding relationships of each parameter in the template;

[0096] 7. Using the AHP points as the input conditions in step 1 as a reference, repeatedly call the H-point calculation template obtained in step 6, calling it 42 times, with each group consisting of 6 calls. Each time, modify the human percentile to different groups (2.5, 5, 10, 50, 90, 95, 97.5, a total of seven groups), and modify H30 to different values ​​(H30 is divided into groups of 5 mm from 127 mm to 405 mm). This yields 6 H-points for different H30 parameters corresponding to different groups of human percentiles. Fit the 6 H-points of each group into a curve to obtain the suitable H-point line for different groups of percentiles; this suitable line changes with the AHP points.

[0097] 8. Using the "Insert - Knowledge Engineering Template - User Features" command, create an intelligent design template for H-point and H-point suitable line based on the process in steps 1 to 7 above, and supplement it (save it as a part file) for subsequent template calls.

[0098] By employing the above steps, the conversion relationships between fixed input parameters, variable parameters, intermediate parameters, and output parameters—defined based on geometric shapes and those specified by design standards—can be quickly solidified into the knowledge engineering template module of CATIA software. The selection of intermediate parameters simplifies and enhances the reliability of this conversion process. Once the conversion relationships are solidified, designers can directly call the template, modify the variable parameters to obtain the output parameters, and utilize the software's built-in display function to obtain a clear structural view of the output parameters, facilitating parameter adjustment and selection during the design process.

[0099] In step 2, the range of H30 values ​​is limited according to standard requirements, so that an error message is displayed when the input exceeds the range. This is because the standard SAE J 1100 specifies the dimensions of H30; for example, the H30 value range for Class A vehicles is 127mm-405mm. Therefore, directly limiting the value range in the program module and displaying an error message when the value exceeds the range can better prevent design errors.

[0100] In step 2, the value of A47 is limited, and a prompt is displayed if the input exceeds the 0-90° range. This is because in actual design, the value of A47 is unlikely to exceed the 0-90° range. Therefore, displaying a prompt when the value exceeds the range in the program module can better prevent design errors.

[0101] In steps 2 and 7, the range of human percentile values ​​is limited to 2.5, 5, 10, 50, 90, 95, or 97.5. This is because the standard SAE J 1517 specifies the calculation formulas for H30 to H-point X corresponding to these human percentiles (2.5, 5, 10, 50, 90, 95, and 97.5). Therefore, human percentiles within this range can directly establish the operational relationship between the input parameters and intermediate parameters according to the standard, facilitating subsequent calculations.

[0102] In step 7, when modifying the value of H30, it is modified in groups of 5 mm from 127 mm to 405 mm. This makes the calculation more uniform and the fitted H-point line more accurate.

[0103] In implementation, step B includes the following steps:

[0104] 9. Open CATIA software. On the toolbar, use the "Insert - Instantiate from Selection" command to switch to the created "H-point and H-point suitable line intelligent design template" part file. Select the "H-point and H-point suitable line intelligent design template" directory tree. According to the window prompts, match the AHP points to be designed with the AHP points in the "H-point and H-point suitable line intelligent design template". After confirming that there are no errors, end the call.

[0105] 10. The "Intelligent Design Template for H Point and H Point Suitable Line" application structure tree is generated on the directory tree of the part files created in step 9. The H point, BOFRP point, and H point suitable lines of 2.5, 5, 10, 50, 90, 95, and 97.5 appear in the 3D data window. Open the structure tree and modify the parameters "H30", "A47", and "human percentile" to meet the requirements of the new vehicle model project. The H point will then be updated accordingly, that is, the corresponding H point and H point suitable line will be displayed synchronously.

[0106] Therefore, this design eliminates the need to consult tables and formulas, or repeatedly calculate based on trigonometric relationships. Users can simply call the model and change the values ​​of the variable parameters to obtain the values ​​of the corresponding H-point and its suitable line, visually displaying their position and structural changes. This significantly improves design efficiency and accuracy.

[0107] Therefore, this invention first organizes the design inputs for the H-point and its suitable line template. The intermediate modeling process is managed through parameters and geometric constraints. The calculations and design rules involved are implemented by embedding calculation formulas and establishing rules using VB conditional statements to drive automatic updates of the geometric model. Finally, the intermediate modeling process is packaged and encapsulated to form an intelligent design template for the H-point and its suitable line. All devices with this feature can then be designed by calling the template. By pre-defining input conditions and designing input values, the entire feature can be adaptively updated to form a product model that meets engineering design requirements. Therefore, compared with existing technologies, the parametric design of the H-point eliminates the need for repetitive product modeling during product design; only a limited number of parameters need to be changed to obtain the corresponding results, greatly shortening the design time. Furthermore, the application results can be automatically updated as the input conditions change, avoiding repetitive work.

Claims

1. A method for intelligent design of a vehicle H point and H point suitable line, characterized in that, The method comprises the following steps: Step A: based on the secondary development function of CATIA software, a knowledge engineering template file capable of visually displaying the design target structure is established, AHP point is taken as fixed input parameter information, H30, A47 and human body percentile are taken as variable parameter input information, BOFRP point coordinate value and H point X value are taken as intermediate parameters, H point and H point suitable line of different human body percentiles are taken as output parameters, the corresponding relationship between input parameter information, intermediate parameters and output parameters in the knowledge engineering template file is established and automatic conversion association is realized; and an intelligent design template about H point and H point suitable line is obtained; Step B: a calling environment of the intelligent design template of H point and H point suitable line is built in CATIA software, the intelligent design template of H point and H point suitable line established in step A is called, different H30, A47 or human body percentile parameters are input according to design needs, the knowledge engineering template automatically runs and the calculated output parameters are visually displayed in the form of graphics; Step A specifically comprises the following steps: (1) open CATIA software to establish a coordinate system, establish AHP point in the coordinate system as a design reference point according to the known AHP point value; the coordinate system is a horizontal rectangular coordinate system, the direction of X coordinate is set along the length direction of the vehicle, the direction of Y coordinate is set along the width direction of the vehicle, and the direction of Z coordinate is set along the height direction of the vehicle; (2) establish the variable parameters to be input and assign values in the coordinate system according to the definition of parameters, the variable parameters include H30, A47 and human body percentile; wherein: H30 is the seat height, which is also the vertical distance from H point to AHP point; when the template model is established, H30 is first taken as a value in the value range; A47 is the angle between the driver's shoe plane and the horizontal plane, that is, the angle between the driver's accelerator pedal and the horizontal plane, A47 is first taken as a value in the value range when the template is established; human body percentile is a human body measurement term, which represents the human body size distribution value; human body percentile represents that the person with a certain human body size and less than the size accounts for a percentage of the total number of statistical objects; human body percentile is first taken as a value in the value range when the template is established; (3) establish the intermediate parameter H point X value and assign values in the coordinate system, the value is the X coordinate value of the obtained output result H point, which is calculated according to the following formulas (1)-(7), X 97.5 = 936.6 + 0.613879z - 0.00186247z 2 (1) X 95 = 913.7 + 0.672316z - 0.00195530z 2 (2) X 90 = 885.0 + 0.735374z - 0.00201650z 2 (3) X 50 = 793.7 + 0.903387z - 0.00225518z 2 (4) X 10 = 715.9 + 0.968793z - 0.00228674z 2 (5) X 5 = 692.6 + 0.981427z - 0.00226230z 2 (6) X 2.5 = 687.1 + 0.895336z - 0.00210494z 2 (7) In formulas (1)-(7), X 97.5 represents the H point X value corresponding to the 97.5 human percentile; X 95 represents the H point X value corresponding to the 95 human percentile; X 90 represents the H point X value corresponding to the 90 human percentile; X 50 represents the H point X value corresponding to the 50 human percentile; X 10 represents the H point X value corresponding to the 10 human percentile; X 5 represents the H point X value corresponding to the 5 human percentile; X 2.5 represents the H point X value corresponding to the 2.5 human percentile; and z represents the H point Z value corresponding to the human percentile, i.e., the value of H30. establish the corresponding relationship between H point X value and different human body percentiles and H30 value according to formulas (1)-(7); (4) take AHP point as the design reference point to obtain the intermediate parameter BOFRP point coordinate value and make BOFRP point, the corresponding relationship between BOFRP point, AHP point and A47 is that the distance between BOFRP point and AHP point is 203 mm, and the angle between the line connecting BOFRP point and AHP point and X axis is the value of parameter A47; (5) make H point, establish H point in the form of three coordinates, the reference point is BOFRP point, and the corresponding relationship between H point three coordinate values and intermediate parameters is: X value = H point X; Y value = 0 mm; Z value = H30 - (Z direction height difference between BOFRP point and AHP point); (6) The processes of steps 1 to 5 are made into an H point calculation process template and saved by applying the "insert-knowledge engineering template-user characteristics" command, and the parameter correspondence is made into the template; (7) The H point calculation process template made in step 6 is repeatedly called 42 times, with 6 times as a group, based on the input condition AHP point in step 1, the human body percentile is modified to different groups each time, and H30 is modified to different values each time, so as to obtain 6 H points of different groups of percentiles under different H30 parameters, and the 6 H points of each group are fitted into a line in the form of a curve to obtain the H point suitable line of different groups of percentiles; the suitable line changes with the change of AHP point; (8) The processes of steps 1 to 7 are made into an H point and H point suitable line intelligent design template by applying the "insert-knowledge engineering template-user characteristics" command, and the template is supplemented for subsequent template calling operation.

2. The intelligent design method for automobile H point and H point suitable line according to claim 1, characterized in that, In step 2, the value range of H30 is limited according to the standard requirements, so that the input value is out of range.

3. The intelligent design method for automobile H point and H point suitable line according to claim 1, characterized in that, In step 2, the value of A47 is limited, and the input value is out of range when it is out of the range of 0-90°.

4. The intelligent design method for automobile H point and H point suitable line according to claim 1, characterized in that, In steps 2 and 7, the value range of human body percentile is limited to 2.5, 5, 10, 50, 90, 95 or 97.

5.

5. The intelligent design method for automobile H point and H point suitable line according to claim 1, characterized in that, In step 7, when modifying the value of H30, the value is modified every 5 mm from 127 mm to 405 mm.

6. The intelligent design method for automobile H point and H point suitable line according to claim 1, characterized in that, Step B includes the following steps: (9) Open CATIA software, switch the "H point and H point suitable line intelligent design template" part file made by applying the "insert-from selected instantiation" command on the tool bar, and point the "H point and H point suitable line intelligent design template" directory tree, and according to the window prompt, pair the AHP point to be designed with the AHP point in the "H point and H point suitable line intelligent design template", and end the calling after confirming that there is no error; (10) The "H point and H point suitable line intelligent design template" application structure tree is generated on the directory tree of the part file established in step 9, and the H point, BOFRP point, 2.5, 5, 10, 50, 90, 95, 97.5 H point suitable line appear in the 3D data window, open the structure tree, modify the parameters "H30", "A47", "human body percentile" to meet the needs of the new vehicle project, then the H point is updated, that is, the corresponding H point and H point suitable line are displayed synchronously.

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