Absorption energy calculation method

Abstract

To provide an absorption energy calculation method capable of accurately and precisely determining absorption energy generated when a test vehicle collides with a collision body.SOLUTION: An absorption energy calculation method comprises a load measurement process for using a plurality of load cells LC1 to LC12 arranged in a vertical direction of a pole part 83 of a collision body 15 to measure loads L1 to L12 at each collision location in a height direction of a test vehicle 11 when the test vehicle 11 collides with the pole part 83, a displacement extraction process for extracting displacements D1 to D12 at each collision location of the test vehicle 11 when it collides with the pole part 83 on the basis of video of the test vehicle 11 colliding with the pole part 83, and an absorption energy calculation process for calculating absorption energy E1 to E12 generated at each collision location of the test vehicle 11 when it collides with the pole part 83 on the basis of the loads L1 to L12 and the displacements D1 to D12 at each collision location of the test vehicle 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for calculating absorbed energy. [Background technology]

[0002] Crash tests using actual vehicles or full-scale prototypes are a necessary method for comprehensively evaluating the safety performance of automobiles and other vehicles, and are also recognized as an effective means for analyzing vehicle traffic accidents in more detail. Several crash test methods have been prescribed by public or private testing and evaluation organizations in each country, and the test evaluation results conducted based on these test regulations are made public, greatly influencing the development of automobiles and vehicles. General-purpose crash test equipment is used as the crash test equipment for actually conducting crash tests, in which a vehicle is towed by a wire rope and crashed into an attachment attached to a rigid wall or into another vehicle.

[0003] In such a crash test facility, a traction mechanism is known that uses, for example, a motor (electric motor or the like) that rotates and drives a winding drum that winds a wire as a power source for towing a vehicle with a wire rope (Patent Document 1). On the other hand, a crash test device of a horizontal drop weight traction type is also known, in which a vehicle connected to a wire rope is towed using the falling motion of a large drop weight as a power source, and crashed into a collision body to perform a vehicle crash test (Patent Document 2). In the crash test device of Patent Document 2, a weight installed inside the large drop weight and a cart for the crash test are connected via a wire rope, and when the weight is allowed to fall freely, the cart is pulled in by the wire rope whose towing direction is changed by a pulley. This is a mechanism in which the test vehicle crashes into the collision body located in the middle between the cart and the large drop weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-46918 A [Patent Document 2] JP 2016-114384 A Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in vehicles such as automobiles, in addition to having a function to suppress functional damage when colliding with other vehicles or obstacles, it is required to develop a structure that absorbs the energy generated in the collision in order to protect the lives of passengers and pedestrians and suppress their damage. Therefore, in vehicle collision tests, it is important to accurately and precisely obtain the absorbed energy generated when the test vehicle collides with a collision body.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an absorbed energy calculation method capable of accurately and precisely determining the absorbed energy generated when a test vehicle collides with a collision body. [Means for solving the problem]

[0007] The present invention comprises the following configurations. 1. A method for calculating absorbed energy of a test vehicle colliding with a collision object, comprising: a load measuring step of measuring a load at each collision portion in a height direction of the test vehicle when the test vehicle collides with the collision body by using a plurality of load meters arranged in a vertical direction of the collision body; a displacement extraction step of extracting a displacement of each of the collision portions of the test vehicle colliding with the collision body based on an image of the test vehicle colliding with the collision body; an absorbed energy calculation step of calculating absorbed energy generated at each of the collision portions of the test vehicle when the test vehicle collides with the collision body, based on a load and a displacement of each of the collision portions of the test vehicle; Including, Method for calculating absorbed energy. Effect of the Invention

[0008] According to the present invention, it is possible to accurately and precisely obtain the absorbed energy generated when a test vehicle collides with a collision body. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a vehicle crash test device. [Diagram 2] FIG. 2 is a schematic side view of a crash test body constituting a crash body against which a test vehicle is collided. [Diagram 3] FIG. 3 is a plan view of the collision location of the test vehicle against the collision body, as viewed from above. [Figure 4] FIG. 4 is a rear view of the collision location of the test vehicle against the collision body, as viewed from the bottom side. [Diagram 5] FIG. 5 is a graph showing an example of the change in load on the pole when the test vehicle crashes. [Figure 6] FIG. 6 is a graph showing an example of the displacement of each collision portion of a test vehicle during a collision. [Figure 7] FIG. 7 is a graph showing the change in absorbed energy at each collision site of a test vehicle during a collision. [Figure 8] FIG. 8 is an explanatory diagram showing the relationship between the absorbed energy at each collision portion and each collision-prepared part of the vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Here, a vehicle crash test device of a falling weight horizontal towing type, which uses the falling motion of a falling weight as a power source, will be described as an example, but a vehicle crash test device of a towing type using an electric motor may also be used. Both crash test devices have in common that the crash test is performed by towing the test vehicle with a wire, although the only difference is the power source.

[0011] (Vehicle crash test equipment) FIG. 1 is a schematic diagram of a vehicle crash test device 200. As shown in FIG. 1, the absorbed energy calculation method according to this embodiment is applied to a crash test (crash evaluation test) performed by a vehicle crash test device 200. The vehicle crash test device 200 is a device (test machine) for performing a crash test of a test vehicle 11, and is installed in a crash test site or the like.

[0012] In general, vehicles are required to have a function for protecting the lives of occupants and surrounding pedestrians, and a function for suppressing functional damage in case of collision with other vehicles, obstacles, etc. For this reason, various developments such as structures for absorbing energy generated by vehicle collisions are continuously carried out. In order to develop such vehicles, vehicle collision tests are performed using a vehicle collision test device 200. In the collision test, a test vehicle 11 is accelerated to a specified speed and collided with a collision body 15, and damage data, etc. of the test vehicle 11 and a simulated occupant (dummy doll, not shown) during and after the collision are collected.

[0013] The vehicle collision test apparatus 200 of this configuration is an apparatus of the dropping weight horizontal traction type, in which a dropping weight 31 is dropped to horizontally pull a cart 13 on which a test vehicle 11 is placed, and the test vehicle 11 is collided with a collision body 15.

[0014] The test vehicle 11 is a commercially available vehicle or a simulated vehicle (a vehicle simulating a commercially available vehicle), etc., and is a test body to be collided with the collision body 15. The test vehicle 11 is, for example, a machine such as an automobile having wheels, and may be, for example, a passenger car (a regular car, a light car, etc.), a freight vehicle such as a truck or a trailer, a passenger transport vehicle such as a bus, or even a motorcycle or a railroad car.

[0015] The vehicle crash test device 200 includes a cart 13, a crash body 15, crash body peripheral equipment 17, a drop weight unit 21, and a towing rope 23.

[0016] The collision body 15 is an object to be collided with by the test vehicle 11, and includes, for example, a concrete barrier 15a and a collision test body 15b. The concrete barrier 15a is a wall made of concrete or the like fixed to the ground G. The collision test body 15b includes at least one of collision attachments corresponding to various collision test standards, for example, an attachment for oblique collision, an attachment for offset collision, an attachment for pole collision, and the like. The collision test body 15b may be, for example, a vehicle other than the test vehicle 11, a pole, a guardrail, or the like. Also, a configuration may be adopted in which the collision test body 15b is not provided.

[0017] The collision body peripheral equipment 17 is equipment arranged around the collision body 15. The collision body peripheral equipment 17 includes, for example, an upper camera 17a, a lower camera 17b, and a lighting device 17c. The upper camera 17a and the lower camera 17b are high-speed cameras, and are devices that respectively capture images of the collision between the test vehicle 11 and the collision body 15. The lighting device 17c is a device that irradiates the test vehicle 11 and the collision body 15 with illumination light. The upper camera 17a is installed above the part of the collision body 15 where the test vehicle 11 collides, and captures images of the collision between the test vehicle 11 and the collision body 15 from above. The lower camera 17b is installed below the part of the collision body 15 where the test vehicle 11 collides, and captures images of the collision between the test vehicle 11 and the collision body 15 from below.

[0018] The drop weight section 21 is a mechanism for dropping the drop weight 31, and includes the drop weight 31, a drop weight tower 33, a buffer device 35, a drop height control device 37, a lower pulley 39, and a movable pulley device 41.

[0019] The drop tower 33 is a tower for dropping the suspended drop weight 31, and includes a plurality of pillars 33a erected on the ground G and a hanging portion 33b suspended across the upper ends of the pillars 33a.

[0020] The drop weight 31 is a weight (weight) that is dropped to tow the test vehicle 11. The drop weight 31 is suspended from a suspension part 33b of the drop weight tower 33 via a movable pulley device 41.

[0021] The shock absorber 35 is a device that receives the falling weight 31. The shock absorber 35 is a device that absorbs the impact caused by the fall of the weight 31. The shock absorber 35 is disposed directly below the weight 31.

[0022] The drop height control device 37 is a device that adjusts and changes the drop height H of the drop weight 31. The drop height H of the drop weight 31 is the distance from the height at which the drop of the drop weight 31 starts to the height at which the drop of the drop weight 31 ends and contacts the buffer device 35. The drop height control device 37 adjusts the drop height H of the drop weight 31 to set the towing speed of the dolly 13, which is determined according to the drop height H, and controls the collision speed of the test vehicle 11 on the dolly 13. The collision speed of the test vehicle 11 is the speed of the test vehicle 11 when the test vehicle 11 collides with the collision body 15. The drop height control device 37 is disposed between the hanging part 33b and the drop weight 31.

[0023] The drop height control device 37 includes a winch 51, a hanging rope 53, and a weight release device 55. The winch 51 is suspended from the hanging part 33b, and the hanging rope 53 is wound and unwound by the winch 51. The hanging rope 53 has the weight 31 connected to its lower end via the weight release device 55. As a result, the weight 31 moves in the vertical direction as the hanging rope 53 is wound and unwound by the winch 51. As a result, the drop height H of the weight 31 is adjusted so that a desired impact speed (the impact speed of the test vehicle 11) is obtained.

[0024] The weight release device 55 is a device that connects the suspension rope 53 and the weight 31 and also separates the connection between the suspension rope 53 and the weight 31. The position of the weight 31 at the moment when the weight release device 55 separates the connection between the suspension rope 53 and the weight 31 becomes the starting point of the fall of the weight 31.

[0025] The towing rope 23 is hung on the lower pulley 39. The lower pulley 39 changes the extending direction of the towing rope 23 from the horizontal direction to the vertical direction. The lower pulley 39 is disposed closer to the drop tower 33 than the impact body 15 is.

[0026] The movable pulley device 41 is a pulley device that connects the suspended part 33b and the drop weight 31, and is provided between the suspended part 33b and the drop weight 31. The movable pulley device 41 makes the towing distance of the test vehicle 11 longer than the falling distance of the drop weight 31. In addition, the movable pulley device 41 makes the towing speed of the test vehicle 11 faster than the falling speed of the drop weight 31. The movable pulley device 41 includes fixed pulleys 61, 63, 65 and movable pulleys 67, 69.

[0027] The fixed pulleys 61, 63, and 65 are provided in the suspended portion 33b. The fixed pulley 61 is disposed above the lower pulley 39. The movable pulleys 67 and 69 are each provided above the drop weight 31, and are disposed at positions spaced apart from each other in the horizontal direction.

[0028] One end of the traction rope 23 is fixed to the cart 13, and the other end is fixed to the hanging part 33b. For example, a wire rope with multiple strands can be used as the traction rope 23. The traction rope 23 transmits the falling motion of the drop weight 31 relative to the hanging part 33b to the cart 13, and pulls the cart 13 in the horizontal direction. The traction rope 23 of this configuration is suspended from the cart 13 side in order of the lower pulley 39, the fixed pulley 61, the movable pulley 67, the fixed pulleys 63 and 65, and the movable pulley 69. The traction rope 23 extending from the lower pulley 39 to the cart 13 is arranged to be laid along a guide groove formed on the floor surface along the running direction A of the cart 13.

[0029] The dolly 13 is connected to the dolly device 30 via a connecting rope 20. A towing rope 23 is connected to the dolly device 30. The dolly 13 has a plurality of wheels 40, and the wheels 40 rotate on a guide rail (not shown) installed on the floor surface, causing the dolly 13 to move along the guide rail. In this manner, the dolly 13 is capable of traveling in a traveling direction A toward the collision body 15.

[0030] The dolly device 30 is a device for smoothly towing the dolly 13, which is towed by the towing rope 23, along a guide groove formed in the floor surface, and the towing rope 23 and the connecting rope 20 are detachably attached to it. A damper 77 is provided on the concrete barrier 15a of the collision body 15, and the traveling dolly 13 is received by the damper 77. When a side impact test of the test vehicle 11 is performed, the test vehicle 11 is placed on the dolly 13 with its front-rear direction facing the width direction of the dolly 13.

[0031] FIG. 2 is a schematic side view of a collision test body 15b constituting the collision body 15 against which the test vehicle 11 is collided. 2, the collision test body 15b of the collision body 15 is a pole collision attachment. This collision test body 15b has a base 81 fixed to the concrete barrier 15a, and a cylindrical pole part 83 provided on the base 81 on the opposite side to the concrete barrier 15a. The pole part 83 is arranged along the vertical direction, and the test vehicle 11 is collided with this pole part 83.

[0032] The pole portion 83 is composed of a plurality of divided bodies P1 to P12 (12 in this example) stacked in the vertical direction. These divided bodies P1 to P12 are provided with load cells (load meters) LC1 to LC12, respectively, on the side of the stand 81. This allows the load cells LC1 to LC12 to measure the horizontal (collision direction) load applied to each divided body P1 to P12 of the pole portion 83 in the collision test body 15b of the collision body 15.

[0033] Fig. 3 is a plan view of the collision location of the test vehicle 11 with the collision body 15 as viewed from above. Fig. 4 is a rear view of the collision location of the test vehicle 11 with the collision body 15 as viewed from the bottom. As shown in Fig. 3, upper measurement points ML are provided in advance on the top surface of the test vehicle 11. Similarly, as shown in Fig. 4, lower measurement points MB are provided in advance on the bottom surface of the test vehicle 11. These upper measurement points ML and lower measurement points MB are provided on a straight line along the moving direction of the test vehicle 11 that passes through the collision point with the pole portion 83 of the collision test body 15b. Furthermore, these upper measurement points ML and lower measurement points MB are provided at positions spaced a preset distance from the side surface of the test vehicle 11 on the side that will collide with the collision body 15.

[0034] (Vehicle crash test) Next, a vehicle crash test using the above vehicle crash test apparatus 200 will be described. In the vehicle collision test device 200 described above, when the connection between the suspending rope 53 and the weight 31 is released by the weight release device 55 and the weight 31 starts to fall, the falling motion of the weight 31 is transmitted to the cart 13 by the towing rope 23. Then, the cart 13 on which the test vehicle 11 is placed is towed as the weight 31 falls, and travels in the travel direction A toward the collision body 15. As a result, the test vehicle 11 on the traveling cart 13 collides with the collision body 15.

[0035] When the test vehicle 11 collides with the collision body 15, the upper camera 17a photographs the collision between the test vehicle 11 and the collision body 15 from above, and the lower camera 17b photographs the collision between the test vehicle 11 and the collision body 15 from below.

[0036] Furthermore, in the collision body 15 against which the test vehicle 11 has collided, the load received from the test vehicle 11 is measured by the pole portion 83 of the collision test body 15b. Specifically, the loads applied to the divided bodies P1 to P12 of the pole portion 83 are measured by the load cells LC1 to LC12, respectively. That is, the loads L1 to L12 at each collision site in the height direction of the test vehicle 11 when the test vehicle 11 has collided with the collision test body 15b of the collision body 15 are measured by the multiple load cells LC1 to LC12 arranged in the vertical direction of the pole portion 83 (load measurement process).

[0037] Fig. 5 is a graph showing an example of the change in load on the pole part 83 when the test vehicle 11 collides. Fig. 5 shows the loads L1, L2, L4, L7 and the total load Lt measured by the load cells LC1, LC2, LC4, LC7.

[0038] Next, based on the images of the collision between the test vehicle 11 and the pole portion 83 captured by the upper camera 17a and the lower camera 17b shown in Figure 1, the displacements D1 to D12 of each collision location of the test vehicle 11 that collided with the pole portion 83 of the collision body 15 are extracted (displacement extraction process).

[0039] In this example, based on the image of the lower camera 17b, the displacement of the lower measurement point MB on the bottom surface of the test vehicle 11 at the time of collision is extracted, and the displacement D1 of the specific collision site corresponding to the divided body P1 of the pole part 83 is obtained. Similarly, based on the image of the upper camera 17a, the displacement of the upper measurement point ML on the top surface of the test vehicle 11 at the time of collision is extracted, and the displacement D12 of the specific collision site corresponding to the divided body P12 of the pole part 83 is obtained. Next, based on the displacements D1 and D12 of these specific collision sites, the displacements D2 to D11 of the other collision sites corresponding to the divided bodies P2 to P11 of the pole part 83 are estimated. The displacements D2 to D12 can be estimated by various interpolation methods, such as linear interpolation.

[0040] Fig. 6 is a graph showing examples of displacements D1 to D12 of each collision site of the test vehicle 11 during a collision. Fig. 6 shows displacements D1, D12 (solid lines in Fig. 6) of specific collision sites obtained from images from the lower camera 17b and the upper camera 17a, and displacements D2 to D11 (dotted lines in Fig. 6) of other collision sites estimated from the displacements D1, D12 of these specific collision sites.

[0041] Based on the loads L1 to L12 and displacements D1 to D12 for each collision portion of the test vehicle 11, absorbed energies E1 to E12 when the test vehicle 11 collides with the pole portion 83 of the collision body 15 are calculated (absorbed energy calculation step). Specifically, the loads L1 to L12 and displacements D1 to D12 for each collision portion of the test vehicle 11 are multiplied together for each collision portion.

[0042] Fig. 7 is a graph showing an example of change in absorbed energy at each collision site of the test vehicle 11 during a collision. Fig. 7 shows absorbed energies E1, E2, E4, and E7 at the collision sites corresponding to the segments P1, P2, P4, and P7, and total absorbed energy Et.

[0043] After the absorbed energies E1 to E12 at each collision site of the test vehicle 11 are obtained by the above procedure, the energy absorption amount for each part of the test vehicle 11 is extracted based on the absorbed energies E1 to E12 for each collision site (energy absorption amount extraction step).

[0044] Fig. 8 is an explanatory diagram showing the correspondence between the absorbed energy E1-E12 for each collision part and each collision-resistant part of the vehicle. As shown in Fig. 8, by matching the absorbed energy E1-E12 for each collision part obtained by the collision test with the vehicle parts, the energy absorption amount of each part can be extracted. This makes it possible to understand the durability and shock absorption of the parts in the vehicle, and to improve safety by improving the vehicle.

[0045] In this way, the absorbed energy calculation method according to this embodiment makes it possible to accurately and precisely calculate and visualize the absorbed energies E1 to E12 at each collision site in the test vehicle 11. This makes it possible to develop safer vehicles by taking into account the amount of absorbed energy calculated from the crash test.

[0046] In addition, the displacements D1, D12 of two specific collision locations are extracted from the video, and the displacements D2 to D11 of other collision locations are estimated from the displacements D1, D12 of these collision locations, so the displacement extraction process can be simplified and processed quickly.

[0047] Furthermore, by providing upper measurement points ML and lower measurement points MB on the top and bottom surfaces of the test vehicle 11, which can be easily photographed with a camera, etc., the displacement of upper measurement points ML and lower measurement points MB can be easily determined from the image at the time of collision.

[0048] In the above embodiment, a side impact test in which the side of the test vehicle 11 is collided with the impact body 15 is described as an example. However, the present invention is not limited to side impact tests and can be applied to impact tests in which the test vehicle 11 is collided with the impact body 15 in any direction.

[0049] Furthermore, the present invention is not limited to a vehicle collision test apparatus of the horizontal towing type, in which a drop weight 31 is dropped to tow the test vehicle 11 and collide it with a collision body 15, but can be applied to any type of vehicle collision test apparatus.

[0050] Furthermore, in the above embodiment, a pole collision attachment is attached to the collision test body 15b, and a pole side collision test is performed, but the present invention is not limited to this. For example, the present invention can be applied even when various conditions such as the shape of the attachment (e.g., the shape of a wall that serves as the collision body) and the collision mode (e.g., a collision mode in which the test vehicle is towed in the same state as normal driving and the test vehicle is caused to collide head-on) are changed.

[0051] As such, the present invention is not limited to the above-described embodiments, and the present invention also contemplates mutual combinations of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the descriptions in the specification and well-known technologies, and these are included in the scope of protection sought.

[0052] As described above, the present specification discloses the following: (1) A method for calculating absorbed energy of a test vehicle colliding with a collision object, comprising the steps of: a load measuring step of measuring a load at each collision portion in a height direction of the test vehicle when the test vehicle collides with the collision body by using a plurality of load meters arranged in a vertical direction of the collision body; a displacement extraction step of extracting a displacement of each of the collision portions of the test vehicle colliding with the collision body based on an image of the test vehicle colliding with the collision body; an absorbed energy calculation step of calculating absorbed energy generated at each of the collision portions of the test vehicle when the test vehicle collides with the collision body, based on a load and a displacement of each of the collision portions of the test vehicle; A method for calculating absorbed energy, comprising: This absorbed energy calculation method makes it possible to accurately and precisely calculate and visualize the absorbed energy at each collision site of a test vehicle, which allows the development of safer vehicles by taking into account the amount of absorbed energy calculated from crash tests.

[0053] (2) The absorbed energy calculation method described in (1), wherein the displacement extraction step extracts displacements of at least two specific collision sites in the collision area of ​​the test vehicle based on an image of the test vehicle colliding with the collision body, and estimates the displacements of other collision sites from the displacements of these collision sites. According to this absorbed energy calculation method, the displacement of another collision portion can be estimated from the displacements of at least two specific collision portions, thereby simplifying the displacement extraction process and enabling rapid processing.

[0054] (3) The absorbed energy calculation method according to (2), wherein the displacement of the specific collision location is the displacement of measurement points provided on the top and bottom surfaces of the test vehicle. According to this absorbed energy calculation method, measurement points are provided on the top and bottom surfaces of the test vehicle, which can be easily photographed with a camera or the like, and the displacement of each measurement point can be easily obtained from the image at the time of collision.

[0055] (4) An absorbed energy calculation method according to any one of (1) to (3), comprising an energy absorption amount extraction step of extracting an energy absorption amount for each part of the test vehicle based on the absorbed energy for each collision part of the test vehicle calculated by the absorbed energy calculation step. According to this method for calculating absorbed energy, it is possible to extract the amount of absorbed energy of each part by matching the absorbed energy of each collision part obtained by the crash test with the vehicle parts. This makes it possible to grasp the durability and shock absorption of the parts of the vehicle, and to improve safety by improving the vehicle. [Explanation of symbols]

[0056] 11 Test Vehicle 15 Collider 83 Pole part (collision body) D1~D12 Displacement E1~E12 Absorbed energy L1~L12 Load LC1~LC12 Load Cells ML Upper measurement point (measurement point) MB Lower measuring point (measuring point)

Claims

1. 1. A method for calculating absorbed energy of a test vehicle colliding with a collision object, comprising: a load measuring step of measuring a load at each collision portion in a height direction of the test vehicle when the test vehicle collides with the collision body by using a plurality of load meters arranged in a vertical direction of the collision body; a displacement extraction step of extracting a displacement of each of the collision portions of the test vehicle colliding with the collision body based on an image of the test vehicle colliding with the collision body; an absorbed energy calculation step of calculating absorbed energy generated at each of the collision portions of the test vehicle when the test vehicle collides with the collision body, based on a load and a displacement at each of the collision portions of the test vehicle; Including, Method for calculating absorbed energy.

2. The displacement extraction step includes extracting displacements of at least two specific collision sites in the collision area of ​​the test vehicle based on an image of the collision of the test vehicle with the collision body, and estimating displacements of other collision sites from the displacements of the specific collision sites. The method for calculating absorbed energy according to claim 1 .

3. The displacement of the specific collision site is the displacement of measurement points provided on the top and bottom surfaces of the test vehicle. The absorbed energy calculation method according to claim 2 .

4. an energy absorption amount extraction step of extracting an energy absorption amount for each component of the test vehicle based on the absorbed energy for each collision portion of the test vehicle calculated in the absorbed energy calculation step; The absorbed energy calculation method according to claim 1 .

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