CN102721826A - Speed testing device and method of non-spliced large-target surface laser light screen - Google Patents

Abstract

The invention discloses a non-splicing large target surface laser light curtain speed test device, which uses a set of inline laser light sources to generate a large target surface laser light curtain with a coverage of 90° to avoid light curtain splicing; adopts "sawtooth The original reflection device with "type structure is used as the reflection cooperation target to improve the laser reflectivity in each area and ensure the signal response when the projectile flies through each area of the large-area light curtain; the spherical reflector with the laser exit hole is placed obliquely (ie The optical axis of the spherical reflector is at an angle to the outgoing optical axis of the laser) before the laser, it converges to form an arc-shaped spot; a "three-stage" structure or an arc-shaped structure is used to splice photosensitive tube arrays in parallel to achieve coverage based on 90° The integrated photoelectric detection of the light emission and reception of the large target laser light curtain; through the use of the maximum negative slope point search algorithm, the timing moment when the projectile flies through the two light curtains is accurately determined, so as to obtain a more accurate projectile speed.

Description

A non-stitching large target surface laser light curtain speed test device and method

technical field

The invention belongs to the technical field of photoelectric detection, and relates to a non-splicing large target surface laser light curtain projectile speed detection device and a detection method.

Background technique

Projectile velocity is an important element among the various parameters of a weapon system. There are many methods for measuring the velocity of projectiles at home and abroad, among which the section velocity measurement method is one of the most important methods. The specific structure of the section device is generally divided into two categories: contact target and non-contact target. The on-off target in the contact target is measured by contact, which has a great influence on the bullet speed and flight attitude, and affects the test accuracy. Non-contact targets include coil targets, acoustic targets, sky curtain targets and light curtain targets, but when using coil targets, there are special requirements for the material of the projectile to be tested, and the target is easily affected by the strength of the magnetic field; The object cannot be measured; the sky curtain target is not suitable for use at night and in rainy days; the light curtain target speed measurement technology has significant advantages in the projectile speed test because of its high speed measurement accuracy, non-contact, and weather-free characteristics. According to the light source used, the light curtain target is divided into laser light curtain target and LED light curtain target. Due to the strong divergence of the LED light source and the lack of energy concentration, it is difficult to test the velocity of the projectile with a large target surface. The laser light curtain target uses laser as the light source, which has unique advantages in the detection of large target surfaces. However, the existing laser targets often use the method of light curtain splicing when detecting large target surfaces, which is difficult to achieve seamless splicing and coplanar splicing. Difficult to adjust, inconvenient to use and maintain.

Contents of the invention

In view of this, the present invention provides a non-splicing large target surface laser light curtain speed test device and method, which can solve the problem of difficulty in seamless splicing caused by the light curtain splicing method used for large target surface detection.

A non-splicing large target surface laser light curtain speed test device of the present invention includes a start light curtain, a stop light curtain and a test module, the start light curtain and the stop light curtain are placed parallel to each other and perpendicular to the ballistic line, and the start light curtain It has the same structure as the stop light curtain, including the original reflection device, laser, spherical mirror and detector, among which:

The original reflection device includes two mutually perpendicular support surfaces and a plurality of reflective screens; the laser is a laser capable of producing a line laser with a divergence angle of 90 degrees, and the laser is placed on the diagonal corresponding to the intersection of the two support surfaces , and the optical axis of the laser coincides with this diagonal;

A plurality of reflective screens are arranged on the two supporting surfaces, and the angle formed between each of the reflective screens and the supporting surface satisfies: the incident angle of all laser rays incident on the reflective screen relative to the reflective screen is less than or equal to 5 °; the size of each reflective screen satisfies: each reflective screen receives laser light within 10 degrees of its position at most; the reflective screen arranged on each support surface forms a sawtooth structure that does not leak light, and the laser light is incident on The sawtooth structure is then reflected back to form a laser light curtain;

The surface of the reflective screen is paved with an original reflective material;

There is a light hole at the center of the spherical reflector, and the light exit hole of the laser fits with the light hole of the spherical reflector from the convex direction of the spherical reflector, and the optical axis of the spherical reflector is not coplanar with the laser light curtain ;

The detector is placed on the focus of the spherical reflector to receive the laser light converged by the spherical reflector, and the output end of the detector is connected to the test module; the focus of the spherical reflector is reflected back by the original reflection device The converging point where the laser light is reflected by the spherical mirror;

The test module extracts the entry time T1 of the projectile according to the signal from the detector that starts the light curtain, extracts the flying time T2 of the projectile according to the signal from the detector that stops the light curtain, and then uses the start light curtain and stop light Divide the distance between curtains by (T2-T1), that is, test the flight speed of the projectile.

The reflective screen at the junction of the two supporting surfaces adopts an arc-shaped concave reflective screen with the intersection point as the center.

The detector includes an arc-shaped base and three photosensitive tubes laid on the base. The head and tail of two adjacent photosensitive tubes are overlapped so that the photosensitive tube covers the entire arc surface of the base. All photosensitive tubes The tube signal output interface is connected in parallel and then output to the test module; the convex surface of the base faces the spherical reflector, and the center point of the base coincides with the focus of the spherical reflector; the arc-shaped surface of the base is reflected back by the original reflection device The shape and size of the laser spot are processed so that the detector fully receives the laser spot.

The detector includes an arc-shaped base and a plurality of photosensitive tubes laid on the base. The photosensitive tubes are compactly arranged along the base, covering the entire arc surface of the base. After all the photosensitive tube signal output interfaces are connected in parallel Output to the test module; the convex surface of the base faces the spherical reflector, and the center point of the base coincides with the focus of the spherical reflector; the arc-shaped surface of the base is based on the shape and size of the laser spot reflected back by the original reflection device Processing is carried out so that the detector fully receives the laser spot.

f为球面镜焦距、L为探测器的宽度、H为激光器发射出的激光的厚度。The angle α formed by the optical axis of the spherical reflector and the laser light curtain satisfies the relational expression:

f is the focal length of the spherical mirror, L is the width of the detector, and H is the thickness of the laser light emitted by the laser.

A test method based on the test device described in claim 1 of the present invention, the specific method is: the projectile passes through the start light curtain and the stop light curtain successively, and differentiates the time domain signal data of the laser light received from the start light curtain processing, and find the time t1 corresponding to the maximum negative slope point; differentially process the time-domain signal data of the laser received from the stop light curtain, and find the time t2 corresponding to the maximum negative slope point; The time interval of two laser light curtains: Δt=t2-t1, and then calculate the projectile velocity v=S/Δt according to the target distance S of the two light curtains.

The invention provides a non-splicing large target surface laser light curtain speed testing device and method, which has the following beneficial effects:

1) A set of straight-line laser light source is used to generate a large target laser light curtain with 90° coverage to avoid light curtain splicing;

2) The original reflection device with "sawtooth" structure is used as the reflection cooperation target to improve the laser reflectivity in each area and ensure the signal response when the projectile flies through each area of the large-area light curtain;

2) A spherical reflector with a laser exit hole is placed obliquely (that is, the optical axis of the spherical reflector is at an angle to the exit optical axis of the laser) in front of the laser, and converges to form an arc-shaped spot; adopts a "three-stage" structure Or the arc-shaped structure is connected in parallel to splice the photosensitive tube array to realize the integrated photoelectric detection of light emission and reception based on the laser light curtain with a large target surface covering 90°.

3) By using the maximum negative slope point finding algorithm, the timing moment when the projectile flies through the two light curtains is accurately determined, so as to obtain a more accurate projectile velocity.

Description of drawings

Fig. 1 is the structural representation of a kind of non-splicing large target surface laser light curtain speed testing device of the present invention;

Fig. 2 is the relative position schematic diagram of the laser of a kind of non-splicing large target surface laser light curtain speed testing device of the present invention, spherical reflector and detector;

Fig. 3 is the structural representation of a kind of detector in the embodiment of a kind of non-splicing large target surface laser light curtain speed testing device of the present invention;

Fig. 4 is the structural representation of another kind of detector in the embodiment of a kind of non-stitched large target surface laser light curtain speed testing device of the present invention;

Fig. 5 is the time-domain curve of the laser signal that receives in a kind of non-stitching large target surface laser light curtain speed test method of the present invention;

Fig. 6 is the curve after differential processing of the laser signal received in a kind of non-splicing large target surface laser light curtain speed test method of the present invention;

FIG. 7 is a schematic diagram of the overall structure of a non-spliced large target surface laser light curtain speed test device of the present invention.

Among them, 1-support surface, 2-laser, 3-reflective screen, 4-concave reflective screen, 5-laser light curtain, 6-optical hole, 7-spherical reflector, 8-arc end face, 9-detection Device, 10-base, 11-photosensitive tube, Ⅰ-start light curtain, Ⅱ-stop light curtain.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The present invention provides a non-splicing large target surface laser light curtain speed test device, as shown in Figure 7, including start light curtain I, stop light curtain II and a test module, start light curtain I and stop light curtain II parallel to each other Placed perpendicular to the ballistic line, the start light curtain I and the stop light curtain II have the same structure, including the original reflection device, the laser 2, the spherical mirror 7 and the detector 9, wherein the laser 2 can generate A line laser with a divergence angle of 90 degrees; the original reflection device includes two mutually perpendicular support surfaces 1 and a reflective screen 3; the laser 2 is placed on the endpoint of the diagonal line corresponding to the intersection of the two support surfaces 1, and the laser 2 The optical axis coincides with this diagonal.

In order to realize the integration of laser emission and reception, multiple reflective screens 3 at a certain angle to the support surfaces 1 are fixed on two mutually perpendicular support surfaces 1 to form a "sawtooth" structure that does not leak light, and the surface of the reflective screens 3 is paved with original reflection Material.

The 90-degree divergent laser light emitted by the laser 2 enters the “sawtooth” structure and is reflected back to form a laser light curtain 5 .

The original reflective device is used as the reflection cooperation target, and the reflective screen 3 is arranged in a "sawtooth" shape with different slopes, in order to match the incident direction of the laser incident reflective screen 3 in the case of a large target surface, and minimize the laser incidence of the original reflective device The angle can effectively enhance the coefficient of retroreflection, so as to obtain high sensitivity in the entire area of the laser light curtain 5.

In order to enable the incident laser to reflect in the original direction, it is required that the incident angle of the laser light on each reflective screen 3 relative to the reflective screen 3 in the incident laser light curtain 5 is less than or equal to 5°, and the size of each reflective screen 3 must meet It can receive laser light within 10° of its position at most. In practice, the number or density of the reflective screen 3 in the "sawtooth" structure is related to the size of the laser light curtain 5: the smaller the area of the laser light curtain 5, the smaller the incident angle range of the laser light relative to the reflective screen 3 can be. When the width is widened, the density of the reflective screen 3 is also reduced; when the laser light curtain 5 is small to a certain extent, for example, when a target surface of 0.5m×0.5m is to be realized, there is no inclined angle between the reflective screen 3 and the supporting surface 1 , that is, parallel to each other.

In practice, the optical path near the diagonals of the two support surfaces 1 is the longest. In order to enhance the detection sensitivity of the area near the vertices of the diagonals, as shown in Figure 1, the reflections at the vertices of the diagonals of the two support surfaces 1 The screen 3 can be arranged as an oblique line, that is, the midpoint of the reflective screen 3 is perpendicular to the diagonal line, or it can be designed as a circular concave reflective screen 4 with the intersection of the two supporting surfaces 1 as the center of the circle, so that the incident The laser light achieves approximate original reflection and achieves the best detection effect.

The center of circle of the spherical reflector 7 is provided with a light hole 6, and the light exit hole of the laser 2 fits with the light hole 6 of the spherical reflector 7 from the convex direction of the spherical reflector 7, as shown in Figure 2, and the spherical reflection The optical axis of the mirror 7 is not coplanar with the laser light curtain 5 .

Detector 9 is placed on the focal point of spherical reflector 7, is used to receive the laser light condensed by spherical reflector 7, and the output end of detector 9 is connected with test module; The focus of spherical reflector 7 is reflected by the original reflection device The returning laser light is then reflected by the spherical reflector 7 at the converging point.

The spherical reflector 7 converges the laser light reflected back by the original reflection device, so that the laser converges on the focus of the spherical reflector 7, and then is received and detected by the detector 9 arranged on the focus. According to the original reflection of the original reflection material The characteristic is not a strict "original direction" return, but a certain divergence. For the line laser beam, the converging spot of the reflected laser is the superposition of the return spot at the light exit of each point of the original reflection material on the reflective screen 3 , the reflected light intensity of each point is dispersed in a certain spot area. When the area of the effective laser light curtain 5 is large and the distance between the reflective screen 3 and the laser 2 is long, the reflected light beam becomes a larger-sized spot, and after being reflected and converged by the spherical mirror 7, it is imaged as an arc-shaped convergent spot. The present invention can adopt a bar-shaped photosensitive tube or photosensitive tube array whose size is equivalent to the converging light spot in the prior art as the detector 9 for receiving and detecting, but since the light spot is arc-shaped and the detector 9 is a plane, the detection will be affected Effect, thus, in this embodiment, the end face of the base 10 of the detector 9 is processed into an arc-shaped end face 8 according to the shape and size of the reflected laser spot, and the arc-shaped end face 8 faces the spherical mirror 7, As shown in Figure 3, in order to make the photosensitive tube 11 cover the entire arc-shaped end face 8 and achieve a good receiving effect, three long strip photosensitive tubes (or photosensitive tube arrays) are used to lay on the arc-shaped end face 8, and The head and tail of two adjacent photosensitive tubes 11 are overlapped, the receiving surfaces of the three photosensitive tubes 11 are approximately arc-shaped, and the seamless reception of the laser spot is ensured, and the signal output interfaces of the photosensitive tubes 11 are connected in parallel and then output to the test module.

Since the receiving surface formed by the overlapping of three photosensitive tubes 11 is not a strict arc shape, the best detection effect is still not achieved, so a plurality of single photosensitive tubes 11 (each photosensitive surface area is very small, Such as 3mm×4mm or smaller) are arranged compactly along the arc-shaped end face 8 to form a light-tight receiving device, ensuring that each photosensitive tube 11 is located at the focal point of the light spot, and the best receiving effect can be obtained, as shown in Figure 4 Show.

f为球面镜焦距、L为探测器9的宽度、H为激光器2发射出的激光光幕5的厚度。然而，随着α角的增大，成像质量会变差，所以实际工程中选择α+2°的倾斜角度即可。In order to make the position of the detector 9 not block the light output of the laser 2, the plane where the center line of symmetry of the arc-shaped end face of the base 10 should form an angle 2α with the laser light curtain 5, and the angle α should satisfy the relational formula:

f is the focal length of the spherical mirror, L is the width of the detector 9 , and H is the thickness of the laser light curtain 5 emitted by the laser 2 . However, as the α angle increases, the imaging quality will deteriorate, so in actual engineering, the inclination angle of α+2° can be selected.

Finally, the test module extracts the entry time T1 of the projectile according to the signal from the photosensitive tube 11 of the light curtain I, and extracts the flying time T2 of the projectile according to the signal from the photosensitive tube 11 of the light curtain II, and then uses the starting light Divide the distance between curtain Ⅰ and stop light curtain Ⅱ by (T2-T1), that is to test the flying speed of the projectile.

The present invention also provides a speed test method based on the above-mentioned device. When the projectile flies through the start light curtain I and the stop light curtain II respectively, part of the light is blocked respectively, and the changed light flux is received and processed by the test module, respectively obtained The projectile passes through the time-domain signal 18 of the light curtain I and the time-domain signal 19 of the stop light curtain II, as shown in Figure 5 and Figure 6. Due to the steep tail of the projectile, the trailing edge of the waveform of the time domain signal is steep, resulting in a point where the slope changes the most. As shown in the upper figure in Figure 6, the time domain signal 18 received from the start-up light curtain I is subjected to differential processing to obtain the signal 20 in Figure 6, and the time t1 corresponding to the maximum negative slope point of the signal 20 is found Carry out differential processing on the time domain signal 19 of the projectile passing the target received from the stop light curtain II to obtain the signal 21 in Fig. 6, and find the time t2 corresponding to the maximum negative slope point of the signal 21; then find out that the projectile passes through the two The time interval of two laser light curtains 5: Δt=t2-t1, then calculate the projectile speed v=S/Δt according to the target distance S of the two light curtains, because the projectile can be more accurately determined to fly over the two light curtains by this method moment, thus ultimately being able to obtain a more accurate projectile flight velocity.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. a non-splicing large target surface laser light curtain speed test device, it is characterized in that, the device comprises start light curtain, stop light curtain and test module, described start light curtain and stop light curtain are mutually parallel and perpendicular to ballistic line Placement, the start light curtain and the stop light curtain have the same structure, both including the original reflection device, the laser (2), the spherical reflector (7) and the detector (9), where: The original reflection device includes two mutually perpendicular support surfaces (1) and a plurality of reflective screens (3); the laser (2) is a laser that can generate a line laser with a divergence angle of 90 degrees, and the laser (2) is placed On the endpoint of the diagonal line corresponding to the intersection of the two supporting surfaces (1), and the optical axis of the laser (2) coincides with this diagonal line; A plurality of reflective screens (3) are arranged on the two support surfaces (1), and the angle formed by each of the reflective screens (3) and the support surface (1) on which it is located satisfies: The incident angle of all the laser light relative to the reflective screen (3) is less than or equal to 5°; the size of each reflective screen (3) meets: each reflective screen (3) can receive within 10 degrees of its position at most laser light; the reflective screen (3) arranged on each support surface (1) forms a sawtooth structure that does not leak light, and the laser light is incident on the sawtooth structure and then reflected back to form a laser light curtain (5); The surface of the reflective screen (3) is covered with original reflective material; There is a light hole (6) at the center of the spherical reflector (7), and the light exit hole of the laser (2) is connected from the convex direction of the spherical reflector (7) to the light hole (6) of the spherical reflector (7). ) fit together, and the optical axis of the spherical reflector (7) is not coplanar with the laser light curtain (5); The detector (9) is placed on the focal point of the spherical reflector (7) to receive the laser light converged by the spherical reflector (7), and the output end of the detector (9) is connected to the test module; the spherical The focal point of the reflector (7) is the converging point where the laser light reflected by the original reflection device is reflected by the spherical reflector (7); The test module extracts the entry time T1 of the projectile according to the signal from the detector (9) that starts the light curtain, and extracts the flight time T2 of the projectile according to the signal from the detector (9) that stops the light curtain, and then uses Divide the distance between the start light curtain and stop light curtain by (T2-T1), that is to test the flight speed of the projectile. 2. A non-splicing large target surface laser light curtain speed test device according to claim 1, characterized in that, the reflective screen (3) at the junction of the two support surfaces (1) adopts an intersection point as the center of the circle An arc-shaped concave reflective screen (4). 3. A non-stitching large target surface laser light curtain speed test device according to claim 1, characterized in that, the detector (9) includes an arc-shaped base (10) and is laid on the base ( 10) of the three photosensitive tubes (11), the head and tail of two adjacent photosensitive tubes (11) are overlapped, so that the photosensitive tubes (11) cover the entire arc surface of the base (10), and all the photosensitive tubes ( 11) The signal output interface is connected in parallel and output to the test module; the convex surface of the base (10) faces the spherical reflector (7), and the center point of the base (10) coincides with the focus of the spherical reflector (7); the base The arc-shaped surface of (10) is processed according to the shape and size of the laser spot reflected back by the original reflection device, so that the detector (9) completely receives the laser spot. 4. A non-stitching large target surface laser light curtain speed test device according to claim 1, characterized in that, the detector (9) includes an arc-shaped base (10) and is laid on the base ( 10) A plurality of photosensitive tubes (11), the photosensitive tubes (11) are compactly arranged along the base (10), covering the entire arc surface of the base (10), and the signal output interfaces of all photosensitive tubes (11) are connected in parallel After output to the test module; the convex surface of the base (10) faces the spherical reflector (7), and the center point of the base (10) coincides with the focus of the spherical reflector (7); the arc of the base (10) The shaped surface is processed according to the shape and size of the laser spot reflected back by the original reflection device, so that the detector (9) completely receives the laser spot. 5. A non-splicing large target surface laser light curtain speed test device as claimed in claim 3, characterized in that the angle α formed by the optical axis of the spherical mirror (7) and the laser light curtain (5) satisfies the relational expression :

f is the focal length of the spherical mirror, L is the width of the detector (9), and H is the thickness of the laser light emitted by the laser (2). 6. a kind of test method based on the described testing device of claim 1, it is characterized in that, projectile passes through start light curtain and stop light curtain successively, the time domain signal data of the laser light that will receive from start light curtain is carried out differential processing , and find the time t1 corresponding to the maximum negative slope point; differentiate the time-domain signal data of the laser received from the stop light curtain, and find the time t2 corresponding to the maximum negative slope point; then find the projectile passing through the two The time interval of the laser light curtain (5): Δt=t2-t1, and then calculate the projectile velocity v=S/Δt according to the target distance S of the two light curtains.

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