JPH0271106A - Apparatus for detecting passing position of flight body - Google Patents

Abstract

PURPOSE:To certainly and accurately detect the passing position of a flight body even when said flight body passes at any angle by generating the shadow corresponding to the passing position of the flight body when the flight body passes along the surface of a film and sensing the same by a light detection means. CONSTITUTION:When a flight body P passes the point (p) within a detection range 16, the shadows 21, 21 due to the flight body P are generated to be detected by photodetectors 19, 20 and the position of the point (p), for example, the distances (x), (y) from a coordinates axes when two sides of the range 16 are set to said coordinates axes can be immediately detected. This detection result is unchangeable at all even when the flight body P passes the range 16 vertically or obliquely. Further, even when an optical system consisting of condensing lenses 8, 9, slit plates 12, 13 and condensing lenses 17, 18 is allowed to approach the center of the range 16 or separated from said range 16, no effect is exerted on the expanse of the range 16 and detection capacity. Therefore, when there is possibility such that the flight body P is shifted from the range, the optical system can be kept away to a sufficiently safe position and the damage due to the flight body P can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a passing position detection device for a flying object, which detects the passing position of a flying object such as a bullet fired from a gun used at a shooting range. be.

[Prior Art 1] As a conventional method for detecting a flying object such as a bullet, there is a sensing bar method that utilizes shock waves generated when a bullet or the like flies at supersonic speed.

First, with reference to FIGS. 3 and 4, the principle of detecting the passing position of an aircraft by sensing shock waves using a sensing bar will be explained.

1 is a metal sensing bar arranged in a direction perpendicular to the traveling direction of the flying object P, and vibration detectors 2 and 3 are installed at both ends of the sensing bar 1.
is the installation.

When the shock wave 4 generated by the flying object P reaches the sensing bar 1, it imparts vibration to the reaching point. This vibration is transmitted through the sensing bar 1, reaches vibration detectors 2.3 provided at both ends, and is sensed.

Now, if the distance from the arrival point Px of the shock wave 4 and the center 0 of the sensing bar 1 to the arrival point Px is X, then the distance from the arrival point Px to the vibration detector 2, and the distance from the arrival point Px to the vibration detector 3. There is a difference of 2x, and Δt=2x/V to both detectors 2.3.
, (V.

The vibrations arrive with a time difference of (the speed of sound in the metal bar). This time difference Δt is determined by detecting the time lag when the vibration detector 2.3 senses the vibration, and the distance Mx from the center is determined by the following formula.

x=V, .Δt/2... (1) Therefore, if the sensing bars 1.5 are arranged perpendicularly in an L-shape and in the same plane as shown in FIG. The passing point can be specified by the orthogonal coordinates of the X and Y axes that pass through the centers of the sensing bars 1 and 5 and are perpendicular to each other.

That is, the X coordinate Px, the y coordinate PY of the passing position of the aircraft P,
If the time difference in sensing the vibration at the sensing bar 1 is Δtx, and the time difference at the sensing bar 5 is Δty, then Px and P- can be obtained as follows.

px=v, -ΔtX/2 pY=v, ·ΔtY/2 [Problems to be Solved by the Invention] However, the above-described conventional sensing bar type has the following problems.

In order to sense shock waves, the sensing bar must be placed close to the position where the flying object passes, but if the flying object deviates from the intended range, the sensing bar may be damaged by the flying object.

Furthermore, since the shock wave has a conical shape, errors will occur unless the aircraft passes perpendicularly to the coordinate plane formed by two orthogonal sensing bars. As is well known, the outline of a cut surface obtained by cutting a cone with a plane inclined to its center line is an ellipse.

Therefore, the shock wave propagates in an elliptical shape and collides with the two sensing bars as shown in FIG.

However, since the shock waves collide in an elliptical shape, the collision point does not indicate the coordinates of the passing position of the aircraft P. That is, if the flying object passes obliquely to the coordinate plane, a detection error of i will occur as shown in FIG.

Furthermore, the one-sensing bar type cannot detect flying objects that do not generate shock waves below the speed of sound.

In view of the above-mentioned circumstances, the present invention has been devised to detect the passing position of the flying object without being damaged by the flying object, without having the detection accuracy affected by the flying object's passing attitude, and even when the flying object is flying below the speed of sound. It makes it possible.

[Means for Solving the Problems] The present invention provides two sets of light emitting means for projecting film-like parallel light rays, the optical axes of which intersect, and the two film surfaces of the parallel light rays are parallel and include the same surface. The present invention is characterized in that two sets of light-receiving means are provided corresponding to the two-way light means, and the light-receiving means can detect the position of a shadow that occurs when an aircraft passes by.

[Function] When an aircraft passes through two membrane surfaces, a shadow is created depending on the passing position, this shadow is detected by the light receiving means, and by determining the position of the shadow detected by the light receiving means, the passing of the aircraft is detected. The location is determined.

[Implementation Example 1] An embodiment of the present invention will be described below with reference to the drawings.

Light sources 6.7 are arranged so that their optical axes are perpendicular to each other in the same plane based on the first factor, and a condenser lens 8.9 is arranged in front of each light source 6.7. Further, in front of the condenser lens 8.9, a slit plate 12.13 having slits 10, 11 of a required length formed in the same plane as the light sources 6, 7 is arranged,
The light from the condensing lens 8.9 is transformed into a film-like parallel beam 14.15
shall be. A rectangular portion where these two parallel light beams 14 and 15 intersect becomes a detection range 16 in which the passing position of the aircraft P can be detected.

A condenser lens 17.18 is disposed at a position facing the slit plate 12.13 and a required distance from the detection range 16, and a light receiver is disposed on the rear side of the condenser lens 17.18 on the optical axis. 19.20 will be established.

The light receivers 19 and 20 have a light-receiving surface that is a collection of minute photosensitive elements, such as a COD, and can sense local changes in light intensity and detect the position on the light-receiving surface where the light intensity has changed. It's something you get.

When the flying object P passes through nine points in the detection range 16 while the film-like parallel light beam is being projected and the light receiver is receiving the light beam,
Shadows 21 and 22 are caused by the aircraft P, and this shadow 21
, 22 are detected by the light receivers 19 and 20, and the positions of two points, for example, the two sides of the detection range 16, are used as coordinate axes, and the distances Mx and y from the coordinate axes can be immediately detected. This detection result does not change in any way whether the flying object P passes through the detection range at an angle or diagonally.

Furthermore, whether the optical system such as the condenser lenses 8, 9, slit plates 12, 13, condenser lenses 17, 18, etc. is brought close to or away from the center of the detection range, the width of the detection range 16 and the detection ability will be affected. Therefore, if there is a possibility that the flying object P is out of the detection range, the optical system can be moved away to a sufficiently safe position, and damage by the flying object can be prevented.

In addition, a cylindrical lens (
If a semi-cylindrical rod lens is used, the slit plate 12.
13 can be omitted.

Figure 2 shows an example of changing the optical system.
is an optical fiber bundle made up of optical fibers 25, 26, and so on. The optical fiber bundle 23 has its base tied in a circular shape to receive sufficient light from the light source, and its tip is arranged in a line so that slit light is emitted from the optical fibers 23. be.

One end of the other optical fiber bundle 24 is arranged in a line to ensure that the slit light can be received, and the other end of the optical fiber bundle 24 is arranged so that the optical fibers 26, 26...- each one is separated. Light is guided to corresponding light receiving elements 27, 27, etc., such as phototransistors.

In this example as well, by monitoring the output of each light-receiving element 27, 27, it is possible to detect the shadow of the flying object P when it passes along with its position.

It goes without saying that the two sets of optical systems do not necessarily have to be perpendicular to each other, and furthermore, it is also possible for the two film-like parallel rays to be slightly shifted in the flight direction of the aircraft.

[Effects of the Invention] As described above, the present invention exhibits the following excellent effects.

(i) No matter what angle the flying object passes through, the passing position can be detected reliably and accurately.

(ii) Equipment installed by the aircraft will not be damaged.

(i) It is also possible to detect the passing position of a subsonic flying object that does not generate a shock wave.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a first embodiment of the present invention, Fig. 2 is a partial explanatory diagram showing another embodiment of the same, and Figs. Principle explanatory diagram, Figure 5 is 2
FIG. 6 is an explanatory diagram showing that the position of a sound source can be specified by orthogonal sensing bars of a book, and FIG. 6 is an explanatory diagram of errors caused by the one-sensing bar system. 6.7 is a light source, 14.15 is a parallel ray, 16 is a detection range, 19.20 is a light receiver, and 21.22 is a shadow. Figure 6

Claims (1)

[Claims] 1) Two sets of light emitting means that emit film-like parallel light rays are arranged so that their optical axes intersect and the two film surfaces of the parallel light rays are parallel to each other, including the same film surface, and are made to correspond to both light emitting means. 1. An apparatus for detecting a passing position of a flying object, characterized in that two sets of light receiving means are provided, and the light receiving means is configured to detect the position of a shadow that occurs when the flying object passes.