JPH0792470B2 - Impact detection identification mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact detection / identification mechanism for detecting and identifying a collision condition when an object collides.

[0002]

2. Description of the Related Art Conventionally, an inertia switch, a breaking switch, a vibration sensor, an acceleration sensor, etc. have been used as a mechanism for detecting a collision of an object, and detect deceleration, object deformation and vibration at the time of collision. . Further, the collision condition is identified by detecting a deceleration, a deformation, a vibration or the like having a certain value or more to discriminate between the collision and other impacts. But,
With these methods, it is impossible to identify the collision conditions such as the collision speed, the collision angle, and the material of the collision object.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an impact detection / identification mechanism capable of detecting and identifying the collision speed, the collision angle, the material of a collided object, and the like at the time of collision. That is the purpose.

[0004]

In order to solve the above-mentioned problems, an impact detection / identification mechanism according to the present invention is mounted in a hollow structure a and is generated by a collision between the hollow structure and an object. An acceleration sensor for detecting a shock wave propagating through the hollow structure; and a filter circuit housed in the hollow structure for discriminating a shock waveform output from the acceleration sensor into frequency bands. , C is housed in the hollow structure , and the frequency band is determined from the correlation between the output waveform of the filter circuit and the collision condition.
An arithmetic circuit for calculating a collision condition by calculating a calculation formula using the acceleration value for each region as a variable is configured.

[0005]

In the impact detection / identification mechanism of the present invention, the acceleration sensor output is filtered by focusing on the fact that the response to the collision speed, the collision angle, the material of the collision body, etc. is different in the high frequency region and the low frequency region of the acceleration sensor output. The circuit discriminates by frequency band is input to the arithmetic circuit to identify the collision condition.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a shock detection / identification mechanism according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In a hollow and strong structure 1, an acceleration sensor 4,
The filter circuit 5 and the arithmetic circuit 6 are housed. Here, the acceleration sensor 4 is attached to, for example, a thick portion of the tip of the structure 1 so as to directly receive a shock wave generated in a collision and transmitted through the structure 1. The filter circuit 5 discriminates the impact waveform of the output of the acceleration sensor 4 for each frequency band, and the arithmetic circuit 6 calculates the collision condition from the output waveform discriminated for each frequency band of the filter circuit 5, and the collision condition calculation result. 7 is output.

In the structure shown in FIG. 1, when the structure 1 collides with the collision body 2, a shock wave 3 is generated, which is detected by the acceleration sensor 4 inside the structure. 2 shows the acceleration sensor 4
3 shows an example of a detected waveform that is the output of the. The impact waveform detected by the acceleration sensor 4 is affected by a collision condition such as a collision velocity, a collision angle, a material of a collided object, etc., depending on a frequency band.

As an example, when the structure 1 collides with the steel plate 8 and penetrates it as shown in FIG. 3, the collision of the acceleration value (peak value) detected by the acceleration sensor 4 inside the structure. The graphs for speed and steel plate thickness are shown in FIGS. 4 and 5. When this is separated for the high frequency and the low frequency of the acceleration sensor output (for example, the high frequency region above 10 kHz is the low frequency region below 10 kHz), the relationship between the collision speed and the acceleration value is shown in FIG. In the high frequency range b and the low frequency range c of the sensor output a, the high frequency range b and the low frequency range c respectively increase as the collision speed increases.
Indicates a large increase and the low frequency range c indicates a small increase. Also, in the relationship between the steel plate thickness and the acceleration value in FIG. 7, the high-frequency range e and the low-frequency range f of the sensor output d increase with the increase of the steel plate thickness, but the high-frequency range e increases. Is small, and the low-frequency range f has a large degree of increase. In this way, the acceleration sensor output is affected by the collision condition depending on the frequency band.

Since the influence of various collision conditions is different for each frequency band, it is possible to make an equation in which various collision conditions are unknowns by using the acceleration value for each frequency band as a variable. By substituting the acceleration value for each frequency band into this equation, various collision conditions can be obtained. In the case of FIG. 6, the collision speed can be calculated, and in the case of FIG. 7, the steel plate thickness can be calculated.

The present invention utilizes such characteristics of the acceleration sensor output. Then, the output of the acceleration sensor is input to the filter circuit 5. The filter circuit 5 discriminates the acceleration sensor output for each frequency band. The output of the filter circuit for each frequency band is affected by different collision conditions as described above. The output of the filter circuit is calculated by the calculation circuit 6 to obtain the collision condition calculation result 7. The arithmetic circuit 6 calculates various collision conditions by using equations in which various collision conditions are unknowns and acceleration values for each frequency band are variables.

The following equation (1) is an example of an equation in which the collision velocity V, which is one of the collision conditions, is an unknown number, the acceleration value in the high frequency range is G ₁ , and the acceleration value in the low frequency range is G _2. Is. V = αG ₁ + βG ₂ + γ (1) (where α, β, γ are constants determined by the acceleration sensor) Since α, β, γ can be known by experiments,
The collision speed V can be obtained by substituting the acceleration values G ₁ and G ₂ into the equation (1).

The arithmetic expression is programmed in the arithmetic circuit 6. Further, the filter circuit 5 and the arithmetic circuit 6 use an analog circuit or a digital circuit.

Further, when a digital circuit is used as the arithmetic circuit 6, instead of performing the arithmetic operation of the equation (1), the acceleration value output in the high frequency region and the low frequency region of the filter circuit 5 are respectively specified. It is also possible to set a threshold value (threshold value of one step or a plurality of steps) and execute an arithmetic process for obtaining an unknown collision condition depending on whether or not the threshold value is exceeded. The identification of the collision angle and the like can be similarly obtained by performing arithmetic processing on the filter circuit output for each frequency band.

[0015]

EFFECTS OF THE INVENTION The present invention is based on the above-mentioned constitution, and is capable of absorbing a shock wave generated by collision between a hollow structure and an object.
The shock wave is detected by the acceleration sensor inside the hollow structure.
The acceleration value for each frequency band obtained through the filter circuit is calculated.
Since a calculation circuit is used to calculate various collision conditions, a mechanism for detecting and identifying a collision of an object (for example, a shell or the like)
Is very effective when applied to.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an impact detection / identification mechanism according to the present invention.

FIG. 2 is a waveform diagram showing an example of an acceleration sensor detection waveform.

FIG. 3 is an explanatory diagram of a state of a structure that has collided with a steel plate and penetrated.

4 is a graph showing an acceleration value of an acceleration sensor output corresponding to a collision speed in the collision shown in FIG.

5 is a graph showing the acceleration value of the acceleration sensor output corresponding to the steel plate thickness in the collision shown in FIG.

6 is a graph showing the acceleration values of FIG. 4 for each frequency band.

FIG. 7 is a graph showing the acceleration values of FIG. 5 for each frequency band.

[Explanation of symbols]

 1 Structure 2 Collision Body 3 Shock Wave 4 Acceleration Sensor 5 Filter Circuit 6 Calculation Circuit 7 Collision Condition Calculation Result 8 Steel Plate

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-3-223676 (JP, A) JP-A-3-67175 (JP, A) JP-A-2-205727 (JP, A) JP-A-62-1 194421 (JP, A) JP 4-224440 (JP, A) JP 3-208751 (JP, A) JP 3-223676 (JP, A) JP 3-67175 (JP, A) JP-A-2-205727 (JP, A) JP-A-62-194421 (JP, A) JP-A-4-224440 (JP, A) JP-A-3-208751 (JP, A)

Claims (1)

[Claims] 1. Attached in a hollow structure,
Hollow structure produced by collision between hollow structure and object
An acceleration sensor for detecting a shock wave traveling through the, have been accommodated in the hollow structure, wherein a filter circuit for discriminating a shock wave for each frequency band which is an output of the acceleration sensor, have been accommodated in the hollow structure, wherein From the correlation between the output waveform of the filter circuit and the collision condition,
And a calculation circuit for calculating a collision condition by calculating a calculation formula using the acceleration value of 1. as a variable .