JP5505244B2 - Impact load measuring system, impact load measuring method, computer program, and computer-readable recording medium - Google Patents

Description

  The present invention relates to an impact load measurement system, an impact load measurement method, a computer program, and a computer-readable recording medium.

  In recent years, in the automobile industry, the development of a vehicle body structure that can reduce injury to passengers during a collision has become an urgent issue. Such a vehicle body structure is composed of a plurality of members, but in order to optimize the collision deformation behavior of the vehicle body, it is extremely important to know the deformation characteristics of the individual members or a combination of some of them. .

  Until now, deformation characteristics of members have often been performed by a quasi-static method. Specifically, the characteristics have been evaluated by deforming the member at a low speed using a large compression tester or the like. However, the actual collision deformation occurs at a high speed and is different from the behavior under a quasi-static load. In particular, it is known that buckling, which is important in a thin plate structure often used in automobiles, behaves differently depending on whether the load is dynamic or quasi-static. In view of this, drop weight tests are often performed to grasp dynamic deformation characteristics. This is to cause dynamic deformation by causing a falling weight to collide with the fixed member from above.

  By using such means, the deformation comes close to that at the time of actual collision, but actually it is necessary to evaluate the absorbed energy at the time of impact deformation of the member. In order to evaluate the absorbed energy, it is necessary to measure the crushing distance of the member and the crushing load at that time. In the case of a dynamic test, it is very difficult to measure this impact load. In general, when a dynamic load is to be measured with a load cell used in a normal quasi-static test, the impact load is affected by the acceleration of the collision object, so that a true collision load cannot be measured.

  With respect to such a dynamic load measuring method, several proposals have been made as methods for measuring the stress-strain relationship of materials. For example, a so-called Kolsky method is known as a high-speed deformation test method, in which only a load at the time of test deformation can be measured by letting a shock elastic wave escape in the longitudinal direction of the rod with an elongated elastic rod. However, this test method was devised to measure the stress-strain relationship of materials, and the test equipment is huge when trying to cope with the long measurement time and large load required for dynamic testing of members. In reality, it is impossible to configure the test apparatus, and even if it is realized, it is difficult to maintain and manage accuracy, and deep experience and knowledge are required to obtain highly accurate data.

  In addition, various proposals have conventionally been made regarding the drop test method. For example, in Japanese Patent Application Laid-Open No. 2007-163222 (the following Patent Document 1), measurement is performed by a clamping device mainly at the top of the drop test platform. An object is hung upward, a piezoelectric sensing platform is separately installed below, a CCD camera is installed outside the piezoelectric sensing platform, and an impact accelerometer is installed on the point to be measured of the object to be measured Then, the holding device is activated using the monitor program, and the object to be measured is freely dropped and recorded from the start until the object to be measured collides with the piezoelectric sensing platform and triggers the circuit. At the same time, the CCD camera is activated to pick up a fall image of the object to be measured, and the fall angle is converted by a computer image. Further, a simulation test of the drop angle is performed through simulation software, and the simulated G value and the accelerometer are actually measured to compare and contrast the G value to obtain an accurate measured value. At the same time, there is described a method for improving the economic effect by improving the problem that a known dropping device easily receives interference and cannot calculate gravitational acceleration.

  However, in the method of Patent Document 1, an accelerometer is installed on a point to be measured on the object to be measured, and the acceleration of the collision object is accurately measured by an impact when the object to be measured collides. As a result, there was a problem that the impact load could not be measured accurately.

  Patent Document 1 describes a CCD camera corresponding to the high-speed camera used in the present invention, but this CCD camera is used for converting the fall angle of the object to be measured, and the present invention. Thus, a method for calculating acceleration data of the load measuring device from an image captured by a high-speed camera has not been studied.

JP 2007-163222 A

  The present invention has been made in view of the problems of the prior art as described above, and accurately measures an impact load by calculating acceleration data of the load measuring device from an image captured by a high-speed camera. It is an object to provide an impact load measurement system, an impact load measurement method, a computer program, and a computer-readable recording medium.

The present invention has been made as a result of intensive studies in order to solve the above-mentioned problems, and the gist of the present invention is the following contents as described in the claims.
(1) A system for measuring an impact load when a collision body collides with a test body,
In the collision body , a load measuring device installed on the side opposite to the side colliding with the test body ,
A high-speed camera that captures the behavior of the impactor;
An acceleration evaluation device that calculates acceleration data of the load measuring device from an image captured by the high-speed camera;
A load evaluation device for extracting load data measured by the load measurement device;
An impact load measurement system comprising: a correction device that corrects the load data based on the acceleration data.
(2) An impact load measuring method using the impact load measuring system according to (1),
Calculating acceleration data of the load measuring device from an image captured by the high-speed camera, extracting the load data measured by the load measuring device, and correcting the load data based on the acceleration data. To measure the impact load.
(3) A computer program for impact load measurement used in the impact load measurement system according to (1),
Calculating acceleration data of the load measuring device from an image captured by the high-speed camera;
A computer program for impact load measurement, wherein load data measured by the load measuring device is extracted and the load data is corrected based on the acceleration data.
(4) A computer-readable recording medium on which the computer program of (3) is recorded.

  According to the present invention, an impact load measurement system, an impact load measurement method, a computer program, and a computer program capable of accurately measuring an impact load by calculating acceleration data of a load measurement device from an image captured by a high-speed camera, and It is possible to provide a computer-readable recording medium, and there are significant industrially useful effects.

It is a figure which illustrates embodiment of the impact load measuring system of this invention. It is a figure which illustrates the processing flow of the impact load measuring method of this invention. It is a figure which shows the Example of the impact load measuring system of this invention. It is a figure which shows the Example of the impact load measuring system of this invention. It is a figure which shows the Example of the impact load measuring system of this invention. It is a figure which shows the Example of the impact load measuring system of this invention. It is a block diagram which shows an example of the computer system which can comprise the impact load measuring system of this invention.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram illustrating an embodiment of an impact load measurement system of the present invention. In FIG. 1, 1 is a collision body, 2 is a load measuring device, 3 is a load evaluation device, 4 is a correction device, 5 is an acceleration evaluation device, and 6 is a high-speed camera.
In a system that measures the impact load when a collision object collides with a test object, for example, a pendulum type accelerometer is conventionally installed on the collision object because the acceleration at the time of collision of the collision object affects the collision load. Thus, a method of measuring the acceleration of the collision object has been adopted. However, it is difficult to install an accelerometer on the collision object, and the pendulum cannot be returned due to an impact at the time of collision, so that the measurement accuracy of acceleration may be extremely lowered.

  Therefore, the impact load measuring system of the present invention is a system for measuring an impact load when the impacting body 1 collides with a test body, and includes a load measuring device 2 installed on the impacting body 1 and the impacting body 1. A high-speed camera 6 that captures the behavior of the load, an acceleration evaluation device 5 that calculates acceleration data of the load measuring device 2 from an image (moving image) captured by the high-speed camera 6, and the load measuring device 2. It has the load evaluation apparatus 3 which extracts load data, and the correction | amendment apparatus 4 which correct | amends the said load data based on the said acceleration data, It is characterized by the above-mentioned.

According to the present invention, since the acceleration data of the load measuring device 2 is calculated from an image (moving image) captured by the high-speed camera 6, it is not necessary to install an accelerometer on the collision object as in the prior art. There is no fear that the acceleration measurement becomes impossible due to the impact of the time, the acceleration of the collision object 1 can be measured accurately, and the load data is corrected on the basis of the accurate acceleration data. Can be measured. The high-speed camera (High Speed Camera) used in the present invention is not limited to any method as long as it can shoot 100 or more images per second, but a high-speed video camera using a CCD element or a CMOS element. FIG. 2 is a diagram illustrating a processing flow of the impact load measuring method of the present invention.
The impact load measuring method of the present invention is an impact load measuring method using the impact load measuring system shown in FIG. 1 described above, and the acceleration of the load measuring device 2 from an image (moving image) taken by the high-speed camera 6. Data is calculated, load data measured by the load measuring device 2 is extracted, and the load data is corrected based on the acceleration data.

  First, an image (moving image) when the colliding body 1 collides with the test body is picked up by the high-speed camera 6, and acceleration data of the load measuring device 2 is calculated from this image (moving image) (Step. 1). Next, load data measured by the load measuring device 2 is extracted (Step. 2).

And by correcting the load data based on the acceleration data,
The acceleration of the impacting body 1 can be accurately measured, and the load data can be corrected based on the accurate acceleration data, whereby an accurate impact load can be measured.

<Example 1>
3-6 is a figure which shows the Example of the impact load measuring system of this invention. As shown in FIG. 3, the collision body 1 was dropped on the test body 7 having a rectangular cross section, and an image at the time of the collision was taken by the high-speed camera 6.
FIG. 4 is a schematic diagram of the load cell, where P is a jig provided on the upper surface of the load measuring device 2, R is the collision body 1, and the contact force F _RE between the collision body and the test body at the time of collision. Is expressed by the following equation (a), and this contact force indicates an impact load.

ここに、F_CL：無荷重時をゼロとしたときの荷重測定値
F_LC´：重力の影響を排除（静止時をゼロ）としたときの荷重測定値
ｇ ：重力加速度
m ：R部の質量
a ：R部の加速度
ma ：衝突体の加速度による慣性力
表１に示す、３種類の材料からなる試験体について衝突試験を行った結果を図５、図６に示す。ここに、HotStampとは、材料を約900℃に加熱して水冷のプレス型で成形するホットプレスという手法により成形性と強度を同時に確保した超高張力鋼板をいう。また、S1180は、引張強度が1180MPa程度の鋼板を示す。なお、衝突速度が8.5km/hのときは、落錘物の自由落下により達成したが、衝突速度が20.0km/hと比較的高速であるときは、落錘物に油圧による初速を付与し達成させた。また試験条件NO.3では、高速度カメラの動画より評価される加速度値との比較のため通常の加速度計を付与した。

Where F _CL : Load measurement value when no load is zero
F _LC ': Load measurement value when the influence of gravity is eliminated (zero when stationary) g: Gravity acceleration
m: Mass of R part
a: R part acceleration
ma: Inertial force due to acceleration of collision object The results of a collision test performed on a test body made of three kinds of materials shown in Table 1 are shown in FIGS. Here, HotStamp refers to an ultra-high-strength steel sheet that simultaneously secures formability and strength by a method called hot pressing in which a material is heated to about 900 ° C. and formed with a water-cooled press die. S1180 indicates a steel sheet having a tensile strength of about 1180 MPa. In addition, when the collision speed was 8.5 km / h, it was achieved by free fall of the falling weight, but when the collision speed was relatively high at 20.0 km / h, an initial speed was applied to the falling weight by hydraulic pressure. Achieved. In test condition No. 3, a normal accelerometer was added for comparison with acceleration values evaluated from high-speed camera videos.

＜試験条件＞
１）高速度カメラの仕様
・仕様：Photron製SA1.1
・撮影範囲： 450mm×260mm
・撮影コマ数：10000FPS
・解像度：1024×592 （バリアブルフレームレート活用）
２）加速度評価装置の仕様
・ 仕様：Photron製ターゲットマーク追尾ソフトウェアTEMA
３）荷重測定装置
・中実円柱上の鉄の塊にひずみゲージを貼りつけたもの
４）荷重評価装置の仕様
・仕様：横河電機製DL750オシロスコープによりデータ記憶・変換
図５に示すように、強度の高いHotStampの方が強度の低いJSC590Yに比べて
衝突体の加速度による慣性力が大きくなっており、高強度鋼等、材料または形状起因で高い減速度が生じる衝突試験では慣性力を考慮する必要があり、本発明の効果が確認された。

<Test conditions>
1) High-speed camera specifications and specifications: Photron SA1.1
・ Shooting range: 450mm × 260mm
-Number of shots: 10000FPS
・ Resolution: 1024 × 592 (using variable frame rate)
2) Specifications and specifications of acceleration evaluation equipment: TEMA target mark tracking software TEMA
3) Load measuring device / Attaching a strain gauge to an iron lump on a solid cylinder 4) Specification / specifications of load evaluating device: Data storage / conversion using Yokogawa DL750 oscilloscope As shown in FIG. High strength HotStamp has higher inertial force due to the acceleration of the impact body than JSC590Y, which has lower strength. Consideration of the inertial force in the impact test where high deceleration is caused by the material or shape of high strength steel etc. Therefore, the effect of the present invention was confirmed.

Further, as shown in FIG. 6, the acceleration value evaluated from the moving image of the high-speed camera is evaluated as a zero value as it stops after the collision, whereas the acceleration value measured with a normal accelerometer is accelerated by the impact. Even if the meter is malfunctioning and stopped, the acceleration value does not become zero, and it was confirmed that the present invention can not only omit the accelerometer that is difficult to install, but can also improve accuracy.
<Example 2>
FIG. 7 is a block diagram showing an example of a computer system that can constitute the impact load measurement system of the present invention. In the figure, reference numeral 1200 denotes a computer PC. The PC 1200 includes a CPU 1201, executes device control software stored in a ROM 1202 or a hard disk (HD) 1211, or supplied by a flexible disk drive (FD) 1212, and collects all devices connected to the system bus 1204. To control. Each function unit of the present embodiment is configured by a program stored in the CPU 1201, ROM 1202, or hard disk (HD) 1211 of the PC 1200.

  A RAM 1203 functions as a main memory, work area, and the like for the CPU 1201. Reference numeral 1205 denotes a keyboard controller (KBC), which controls to input a signal input from the keyboard (KB) 1209 into the system main body. Reference numeral 1206 denotes a display controller (CRTC) which performs display control on the display device (CRT) 1210. A disk controller (DKC) 1207 is a hard disk (boot program (start program: a program that starts execution (operation) of personal computer hardware and software)), a plurality of applications, editing files, user files, a network management program, and the like. HD) 1211 and flexible disk (FD) 1212 are controlled.

  Reference numeral 1208 denotes a network interface card (NIC) that exchanges data bidirectionally with a network printer, another network device, or another PC via the LAN 1220.

  The functions of the above-described embodiments can also be realized by a computer executing a computer program. Further, means for supplying a computer program to a computer, for example, a computer-readable recording medium such as a CD-ROM in which such a program is recorded, or a transmission medium such as the Internet for transmitting such a program is also applied as an embodiment of the present invention. be able to. A computer program product such as a computer-readable recording medium in which the program is recorded can also be applied as an embodiment of the present invention. The computer program, recording medium, transmission medium, and computer program product are included in the scope of the present invention. As the recording medium, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory, a ROM, or the like can be used.

By using such an apparatus configuration, a system for measuring an impact load when a collision body collides with a test body, a load measuring device installed on the collision body,
A high-speed camera that captures the behavior of the collision object, an acceleration evaluation device that calculates acceleration data of the load measuring device from an image (moving image) captured by the high-speed camera, and load data measured by the load measuring device An impact load measurement system, an impact load measurement method, a computer program, and a computer readable medium, comprising: a load evaluation device that extracts the load data; and a correction device that corrects the load data based on the acceleration data. A recording medium can be provided.

DESCRIPTION OF SYMBOLS 1 Colliding body 2 Load measuring device 3 Load evaluation device 4 Correction device 5 Acceleration evaluation device 6 High-speed camera 7 Specimen

Claims (4)

A system for measuring an impact load when a collision object collides with a test object,
In the collision body , a load measuring device installed on the side opposite to the side colliding with the test body ,
A high-speed camera that captures the behavior of the impactor;
An acceleration evaluation device that calculates acceleration data of the load measuring device from an image captured by the high-speed camera;
A load evaluation device for extracting load data measured by the load measurement device;
An impact load measurement system comprising: a correction device that corrects the load data based on the acceleration data. An impact load measurement method using the impact load measurement system according to claim 1,
Calculating acceleration data of the load measuring device from an image captured by the high-speed camera;
An impact load measuring method, wherein load data measured by the load measuring device is extracted and the load data is corrected based on the acceleration data. A computer program for impact load measurement used in the impact load measurement system according to claim 1,
Calculating acceleration data of the load measuring device from an image captured by the high-speed camera;
A computer program for impact load measurement, wherein load data measured by the load measuring device is extracted and the load data is corrected based on the acceleration data. A computer-readable recording medium on which the computer program according to claim 3 is recorded.

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