A method and storage medium for determining the worst collision direction of a main instrument panel

Abstract

The present invention discloses a method and storage medium for determining the worst collision direction of a main instrument panel, the method comprising: S1, selecting a head collision point on the surface of the main instrument panel, making a normal through the head collision point, and obtaining the position of the center of the ball on the normal; S2, taking a sample fulcrum within the range of motion of the swing arm fulcrum according to the designed step length; S3, connecting the center of the ball and the sample fulcrum to form a swing arm, and screening out the effective swing arm; S4, determining the motion surface of each effective swing arm; S5, determining the corresponding collision direction on the motion surface of each effective swing arm; S6, the collision direction corresponding to the smallest angle with the normal is the worst collision direction. The present invention solves the problem that the worst head collision direction corresponding to the head collision point cannot be accurately defined in the prior art, improves the reliability of making the head collision direction, and reduces human manual errors; and the whole set of processes is made into a software program to realize the rapid production of the head collision direction, saving manpower and greatly improving work efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of automobile component testing, and in particular to a method for determining the worst collision direction of a main instrument panel and a storage medium. Background Art

[0002] The development of the main instrument panel must meet the requirements of the national standard GB11552 passenger internal protrusion regulations for head impact performance. It is stipulated that a ball head model with a diameter of 165mm and a mass of 6.8kg will hit the surface of the instrument. The fulcrum is required to be movable within the range of 127mm in the +X direction and 19mm in the +Z direction from the H point, and the arm length is adjustable from 736 to 840mm (the distance from the fulcrum to the top of the ball). It hits the instrument panel surface at a speed of 24.1kg / h to ensure that the maximum average acceleration within 3ms does not exceed 72g. The head impact speed is required to be constant. Only when the collision direction is in the relatively worst direction within the regulatory requirements can this test fully verify the structure of the main instrument panel.

[0003] In the early stage of the development of the main instrument panel, automobile manufacturers generally conduct head-on collision tests in advance to optimize the structural design of the main instrument. However, it is known that the tests and virtual simulations use subjective methods, fixed arm length, or methods such as determining the swing arm fulcrum to determine the collision direction. Generally, the following are shown: 1. The swing arm fulcrum is only based on the H point to make the direction of the head impactor, and the cantilever length meets 736-840mm, that is, the head impact direction of a certain point is defined. This technology will cause the front end collision area to be omitted, and the fulcrum is unique, resulting in a unique head impact direction, and the worst collision direction cannot be found; 2. The swing arm fulcrum is not fixed, the fulcrum is on the ZX plane, the X and Z coordinates are consistent with the H point, and the cantilever length meets 736-840mm, that is, the head impact direction of a certain point is defined. In this way, the collision direction is quite different from the actual worst collision direction, and the equivalent speed is difficult to decompose. The above operations cannot accurately determine the worst collision direction, resulting in the test being unable to identify the collision point that does not meet the regulations, greatly reducing the reliability and consistency of the test. Summary of the invention

[0004] In order to make up for the shortcomings of the existing welding defect detection method, the present invention aims to provide a method and a storage medium for determining the worst collision direction of a main instrument panel.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] In one aspect, the present invention provides a method for determining the worst collision direction of a main instrument panel, the method comprising:

[0007] S1. Select a head collision point on the surface of the main instrument panel, draw a normal line perpendicular to the section where the head collision point is located through the head collision point, and obtain the center position of the ball on the normal line;

[0008] S2, taking point H as the base point, select the swing arm fulcrum within the set range of -X direction and +Z direction as the sample fulcrum;

[0009] S3, connecting the ball center and the sample fulcrum to form a swing arm, and selecting the effective swing arm;

[0010] S4, determining the motion surface of each effective swing arm;

[0011] S5. determining the corresponding collision directions on the motion surfaces of the effective swing arms;

[0012] S6. The collision direction corresponding to the smallest angle with the normal is the worst collision direction.

[0013] Preferably, in step 1, the vector of the normal line points outside the main instrument panel shaping surface.

[0014] Preferably, in step 1, the method for obtaining the center position of the ball is: take a point on the normal line that has the same radius as the impact ball head, and the position of the point is the center position of the ball.

[0015] It is further preferred that in step 1, the radius of the impact ball head is 82.5 mm.

[0016] Preferably, in step 2, the swing arm fulcrum is based on point H within the range of 127 mm in the -X direction (from the rear of the vehicle to the front of the vehicle) and 19 mm in the +Z direction, and 2413 sample fulcrums are taken at a single-side step length of 1 mm.

[0017] Preferably, in step 3, effective swing arms are screened out according to 653.5 mm < swing arm length < 757.5 mm.

[0018] Preferably, the moving surface of the effective swing arm is: a surface formed by the effective swing arm and a perpendicular line passing through the center of the sphere.

[0019] Preferably, in step 5, the step of determining the collision direction is: taking the effective swing arm fulcrum as the center of the circle and the effective swing arm length as the radius, a circular motion trajectory is drawn on each motion surface, and the tangent line passing through the center of the sphere and tangent to the circular motion trajectory is the line along which the collision direction is located.

[0020] The collision direction is: a direction passing through the center of the ball and tangent to the circular motion trajectory formed by the end of the effective swing arm on the motion surface, and the vector of this direction points to the main instrument panel shaping surface.

[0021] On the other hand, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program implements the steps of the method described above when executed by a processor.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The present invention defines a fast and accurate worst collision direction for each collision point through mathematical logic design and software equipment development. This solves the problem that the worst head collision direction corresponding to the head collision point cannot be accurately defined in the prior art, improves the reliability of making the head collision direction, and reduces manual errors. The entire process is made into a software program to achieve fast head collision direction making, saving manpower and greatly improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of determining the worst collision direction of the main instrument panel according to an embodiment of the present invention;

[0025] Figure 2 is a schematic diagram of the inner molding surface of the main instrument panel according to an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of determining the center of a sphere on a main instrument panel according to an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the range of motion of the swing arm fulcrum according to an embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the connection of the effective swing arm of the embodiment of the present invention;

[0029] Figure 6 is a schematic diagram of the motion surface of the effective swing arm of an embodiment of the present invention;

[0030] Figure 7 Schematic diagram of different motion trajectories of the ball head model according to an embodiment of the present invention;

[0031] Figure 8 is a schematic diagram of the angles between all collision directions and the normal line in an embodiment of the present invention;

[0032] Fig. 9 is a schematic diagram of collision directions corresponding to all collision points in an embodiment of the present invention;

[0033] Fig.10 It is the operation interface of the computer program of the embodiment of the present invention.

[0034] Figure numerals: 1-main instrument panel, 2-impact ball head, 3-normal line, 4-center of ball, 5-effective swing arm, 6-vertical line, 7-circular motion trajectory, 8-collision direction, 9-angle, 10-effective swing arm fulcrum, 11-motion surface. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments. However, it should be understood that the drawings are only for illustrative purposes and cannot be understood as limiting the present invention. In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only for illustrative purposes and cannot be understood as limiting the present invention.

[0036] The inner molding surface of the main instrument panel is known. According to the structural strength distribution, points A1, A2, A3...An are selected as the head collision points at the stronger structural position. According to the regulatory requirements, the fulcrum of the ball head swing arm can move within the range of 127mm in the -X direction and 19mm in the +Z direction with point H as the base point, and the arm length (the length from the center of the ball to the sample fulcrum) is adjustable within the range of 653.5-757.5mm. The contact between the ball head and the head collision point of the main instrument panel is guaranteed, and the collision direction of the ball head is the tangent direction of the motion trajectory around the sample fulcrum in the vertical plane.

[0037] like Figure 1 As shown, the present invention provides a method for determining the worst collision direction of a main instrument panel, the method comprising the following steps:

[0038] 1) Input

[0039] Given the inner molding surface of the main instrument panel 1, points A1, A2, A3, ..., A10 are selected as the head collision points at the stronger positions of the structure according to the structural strength distribution. Figure 2 shown.

[0040] 2) Select A1

[0041] Taking A1 as an example, the method for determining the worst collision direction of other head collision impact points can refer to the method for determining point A1.

[0042] 3) Determine the center position of the ball

[0043] like Figure 3 As shown, according to the head collision point A1 and the surface on which it is located, the impact ball head 2 is tangent to the surface, passes through the collision point A1, and is perpendicular to the section where A1 is located as the normal 3, the vector of the normal 3 points outside the modeling surface, and the point on the normal 3 that is 82.5 mm away from the head collision point (that is, the radius of the impact ball head 2) is taken as the location of the ball center 4.

[0044] 4) Determine the effective swing arm and sample fulcrum

[0045] Since the swing arm pivot point can move within a range of 127 mm in the -X direction and 19 mm in the +Z direction with the H point as the reference point, for the movement range of the sample pivot point, 2413 sample pivot points are taken at a step size of 1 mm on each side, as Figure 4 shown.

[0046] For all the arm lengths Li of the connecting lines between the center of the ball 4 and the sample pivot points, a judgment statement is set to screen according to the requirement of 653.5 mm < Li < 757.5 mm. If the requirement is met, it is a valid swing arm 5 and a valid swing arm pivot point 10, as Figure 5 shown, but not exhausted.

[0047] 5) Determine the movement plane

[0048] The connecting line between the valid swing arm pivot point 10 screened in step 4 and the center of the ball 4 is the valid swing arm 5 for hitting the ball head 2. The plane formed by the valid swing arm 5 and the perpendicular line 6 passing through the center of the ball 4 is the movement plane 11, as Figure 6 shown (only two movement planes 11 are shown as examples).

[0049] 6) Determination of the collision direction

[0050] On their respective movement planes 11, with the valid swing arm pivot point 10 of the valid swing arm 5 as the center and the swing arm length Li as the radius, a circle is drawn on the movement plane 11, which is the circular movement trajectory 7 of the ball head 2 hitting the instrument panel. The tangent line passing through the center of the ball 4 and tangent to the circular movement trajectory 7 coincides with the line where the collision direction 8 is located. The vector direction of the collision direction 8 points to the styling surface of the instrument panel, as Figure 7 shown.

[0051] 7) Determine the most severe collision direction of point A1

[0052] For all the acute angles 9 between the collision directions 8 corresponding to the valid swing arm pivot points 10 and the normal line 3, the collision direction 8 corresponding to the minimum angle is the most severe collision direction of the A1 impact point. As Figure 8 listed, the included angle of 19.59° is the minimum angle, so the corresponding collision direction 8 is the most severe collision direction.

[0053] 8) Determine the most severe collision directions of the ball heads at points A2... A10

[0054] Set a loop program to complete the most severe collision directions of the other A2... A10 collision points according to the methods in steps 1 - 7 above, as shown in 9.

[0055] The above manufacturing method is made into a software program through mathematical calculations and logic, as Fig.10 shown. The software requires input of the collision surface, H point, and impact point to determine the placement position of the ball head and the most severe collision direction, with high calculation efficiency. The production time for the collision directions of 10 points is about 5 s.

[0056] The present invention has the following specific beneficial effects:

[0057] 1) Efficient and accurate production of head collision direction provides accurate collision direction input for virtual simulation and testing, improving the reliability and consistency of virtual simulation and testing.

[0058] 2) Accurately test product performance in advance, provide a stable reference for product design, and make predictions for subsequent regulatory tests.

[0059] 3) The solution has been developed into software and embedded in CATIA for use, which improves work efficiency, greatly reduces labor costs and reduces the rate of human errors.

[0060] The above is only a preferred embodiment of the present invention, but the present invention is not limited to the above specific embodiments. Those skilled in the art may make some modifications, supplements or use similar methods instead without departing from the principle of the present invention, which should also be regarded as the protection scope of the present invention.

Claims

1. A method for determining the worst collision direction of the main instrument panel, It is characterized in that The method comprises: S1. Select a head collision point on the surface of the main instrument panel (1), draw a normal line (3) perpendicular to the section where the head collision point is located through the head collision point, and obtain the position of the ball center (4) on the normal line (3); S2, taking point H as the base point, select the swing arm fulcrum within the set range of -X direction and +Z direction as the sample fulcrum; S3, connecting the ball center (4) and the sample fulcrum to form a swing arm, and selecting an effective swing arm (5); S4, determining the motion surface (11) of each effective swing arm (5); S5, determining the corresponding collision direction (8) on the motion surface (11) of each effective swing arm (5); S6, the collision direction (8) corresponding to the smallest angle with the normal (3) is the worst collision direction (8); The motion surface (11) of the effective swing arm (5) is a surface formed by the effective swing arm (5) and a perpendicular line (6) passing through the center of the sphere (4); the steps for determining the collision direction (8) are as follows: a circular motion trajectory (7) is drawn on each motion surface (11) with the effective swing arm fulcrum (10) as the center of the circle and the length of the effective swing arm (5) as the radius; a tangent line passing through the center of the sphere (4) and tangent to the circular motion trajectory (7) is the line along which the collision direction (8) is located.

2. The method for determining the worst collision direction of the main instrument panel according to claim 1, It is characterized in that In S1, the vector of the normal line (3) points outside the design surface of the main instrument panel (1).

3. The method for determining the worst collision direction of the main instrument panel according to claim 1, It is characterized in that In S1, the method for obtaining the position of the ball center (4) is: take a point on the normal line (3) that has the same radius as the impact ball head (2), and the position of the point is the position of the ball center (4).

4. The method for determining the worst collision direction of the main instrument panel according to claim 3, It is characterized in that In S1, the radius of the impact ball head (2) is 82.5 mm.

5. The method for determining the worst collision direction of the main instrument panel according to claim 1, It is characterized in that In S2, the swing arm fulcrum is based on point H within the range of 127 mm in the -X direction and 19 mm in the +Z direction, and 2413 sample fulcrums are taken at a single-side 1 mm step length.

6. The method for determining the worst collision direction of the main instrument panel according to claim 1, It is characterized in that In S3, according to 653.5 mm < swing arm length < 757.5 mm, the effective swing arm (5) is screened out.

7. The method for determining the worst collision direction of the main instrument panel according to claim 1, It is characterized in that The vector of the collision direction (8) points into the styling surface of the main instrument panel (1).

8. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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