CN101285666A - Laser target shooting device based on four-quadrant photodetector - Google Patents

Abstract

A laser target shooting device based on a four-quadrant photodetector includes a laser emitting system, a laser receiving system, and a signal processing part. The detector is composed of: the laser beam passes through the half-mirror, and the light is divided into two paths, one path of light is transmitted to the substrate, and the other path of light is reflected by the half-mirror, and then imaged through the imaging screen, lens, and filter in turn. On the photosensitive surface of the four-quadrant photodetector; the signal of the four-quadrant photodetector is amplified and shaped by the signal processing circuit, then connected to the A/D conversion circuit, and finally connected to the computer for signal processing and simulation display of the laser impact point position, Shooter score display.

Description

Laser target shooting device based on four-quadrant photodetector

technical field

The invention belongs to the technical field of lasers, in particular to a laser target shooting device based on a four-quadrant photodetector for simulated target shooting training.

Background technique

At present, laser target shooting devices are widely used in entertainment and military training. Entertainment laser target shooting devices are mainly produced by Nanjing Leisheng and Shenyang Jinshan. In terms of military shooting training, many countries research laser target shooting devices and use laser bullets instead of traditional bullets to save training expenses. There are also individual units in our country that are engaged in the research of laser target shooting devices and produce corresponding products, but due to these The product cannot fully meet the requirements of military training, so the scope of application is extremely limited. The common laser target shooter has an obvious disadvantage, that is, it uses a large number of photodiodes arranged on the target surface as a detector array, which is not only expensive, but also complicated for subsequent signal processing.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention provides a laser target shooting device based on a four-quadrant photodetector, which uses a four-quadrant photodetector as the photodetector, which not only greatly improves the accuracy and stability of the target shooting device, but also The cost is reduced, and the subsequent processing of the signal is simple.

The laser target shooting device mainly includes a laser emitting system, a laser receiving system and a signal processing part. The laser receiving system is composed of a substrate, a half mirror, an imaging screen, a lens, a filter and a four-quadrant photodetector; The laser beam emitted by the system passes through the half-mirror, and the light is divided into two paths. One path of light is transmitted to the substrate, and the other path of light is reflected by the half-mirror, and is imaged on the four sides through the imaging screen, lens, and filter in turn. The photosensitive surface of the quadrant photodetector; the signal of the four-quadrant photodetector is amplified and shaped by the signal processing circuit, connected to the A/D conversion circuit, and finally connected to the computer for further processing and display.

The semi-transparent and semi-reflective mirror in the laser target shooting device forms an angle of 45° with the horizontal direction, and the imaging screen is a light-transmitting thin screen placed horizontally. The detector adopts PIN four-quadrant photodetector or APD four-quadrant photodetector, which has four symmetrical photosensitive surfaces, and the photosensitive surfaces are circular or rectangular. Using the different areas of the light spot on the four quadrants of the four-quadrant photodetector to cause the difference in the output signals of the four quadrants, determine the offset of the center of the light spot on the four-quadrant photodetector, and the deviation of the center of the light spot relative to the four-quadrant photodetector There is a mathematical relationship between the displacement and the offset of the spot center on the target surface, so as to establish a mathematical model of the four-quadrant output signal and the offset angle and amplitude of the spot on the target surface. The output signal of the four-quadrant photodetector is pre-amplified and main-amplified, and then the signal is connected to the A/D conversion circuit, and the A/D conversion is performed by an ordinary data acquisition card. Except for the vertical plane corresponding to the half-mirror, the entire receiving system is in a closed dark room. This target shooter needs to combine software part to complete its function. The software part is implemented by using the graphical programming language LABVIEW for developing virtual instruments. The software part mainly includes signal processing, simulation display of laser impact position, and display of shooter's performance.

The advantage of the present invention is mainly that a four-quadrant photoelectric detector is used as a detector, and the position of the laser on the target is judged through the offset of the light spot relative to the center position of the photosensitive surface of the detector, thereby greatly improving the accuracy of the target shooting device.

Description of drawings

Fig. 1 is the hardware principle block diagram of this laser target shooting device;

Fig. 2 is a software flow chart of the laser target shooting device.

Detailed ways

The structure of this laser target shooting device hardware part is referring to Fig. 1, mainly comprises laser emitting system 1, laser receiving system 2 and signal processing part 3, and described laser receiving system is made up of substrate 21, half mirror 22, imaging screen 23, Lens 24, filter plate 25 and four-quadrant photodetector 26 are made up; Laser beam passes through half mirror 22, and light is divided into two paths, one road light is transmitted on the substrate 21, and another road light is passed through half mirror 22 After reflection, images are formed on the photosensitive surface of the four-quadrant photodetector 26 through the imaging screen 23 , the lens 24 , and the filter 25 in sequence. The semi-transparent and semi-reflective mirror in the laser target shooting device forms an angle of 45° with the horizontal direction, and the imaging screen is a light-transmitting thin screen placed horizontally. The detector adopts PIN four-quadrant photodetector or APD four-quadrant photodetector, which has four symmetrical photosensitive surfaces, and the photosensitive surfaces can be circular or rectangular. Determine the offset of the spot center on the four-quadrant photodetector by using the different areas of the light spot on the four quadrants of the four-quadrant photodetector to cause the difference in the output signals of the four quadrants

The areas of the light spots in the four quadrants of the four-quadrant photodetector are different, and the corresponding currents generated by the four quadrants are different. The currents generated by the first to fourth quadrants are: i ₁ , i ₂ , i ₃ , and i ₄ . Then the horizontal and vertical offsets of the light spot are:

$\left.\begin{array}{c}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}\\ \mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; k</span>}\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}}\end{array}\right\}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

K in the formula is a proportional coefficient, which is a constant. When the center of the light spot coincides with the center of the four-quadrant detector, the currents i ₁ , i ₂ , i ₃ , and i ₄ generated by the four-quadrant cathode are all equal, and the straightness error in the two directions is zero; when the centers of the two do not coincide, The offset in the two directions can be obtained by the above formula (1), the offset amplitude ρ and angle They are:

分别为：Thus, the offset of the center of the spot on the target surface relative to the center of the target surface, the magnitude of the offset ρ' and the angle can be obtained

They are:

when

(k-1)d≤ρ′<kd, k=1, 2, 3, 4, 5 (4)

Where d is the distance between each ring on the target surface. Then the number n of hit rings is:

n=11-k (5)

After the signal of the four-quadrant photodetector is amplified and reshaped by the signal processing circuit 3, it is connected to the A/D conversion circuit, and finally input into the computer 5 for signal processing by software, and the angle and amplitude of the center of the light spot are calculated to determine the position of the light spot on the target. The position of the surface, and realize the simulation display of the laser impact position and the display of the shooter's performance.

A/D conversion is carried out by common data acquisition card. This target shooter needs to combine software part to complete its function. The software part is implemented by using the graphical programming language LABVIEW for developing virtual instruments. The software part mainly includes signal processing, simulation display of laser impact position, and display of shooter's performance.

Refer to Figure 2 for the software flow chart. Call the corresponding dynamic link in LABVIEW to drive the data acquisition card, realize data acquisition and digital output, and calculate the spot offset angle and amplitude from the output calculation amount, so that according to the offset angle and magnitude to judge whether it is off-target. If there is no miss, the dot position will be displayed on the simulated target surface, if there is no miss, it will not be displayed. At the same time, the score of the shooter is displayed on the interface.

Claims (6)

1, a kind of laser target shooting device based on four-quadrant photo detector, comprise that laser transmitting system, laser accepts system and signal processing, it is characterized in that: described laser is accepted system and is made up of substrate, semi-transparent semi-reflecting lens, imaging screen, lens, filter plate and four-quadrant photo detector; Laser beam that laser transmitting system sends is through semi-transparent semi-reflecting lens, and light is divided into two-way, and one road light is transmitted on the substrate, another road light by semi-transparent semi-reflecting mirroring after, successively through imaging in behind imaging screen, lens, the filter plate on the four-quadrant photo detector photosurface; Signal on the four-quadrant photo detector inserts the A/D change-over circuit after the amplification of signal processing circuit, shaping, insert computer at last and handle, and realizes that the simulation demonstration of laser position, ejaculator's achievement show; The centre wavelength of optical filter described in the light path is 630～650nm.

2, the laser target shooting device based on four-quadrant photo detector according to claim 1 is characterized in that: semi-transparent semi-reflecting lens is from the horizontal by 45, and imaging screen is the thin screen of the printing opacity of horizontal positioned.

3, the laser target shooting device based on four-quadrant photo detector according to claim 1 and 2, it is characterized in that: detector adopts PIN four-quadrant photo detector or APD four-quadrant photo detector, it has four to have symmetric photosurface, and photosurface is circle or rectangle.

4, the laser target shooting device based on four-quadrant photo detector according to claim 3, it is characterized in that: utilization hot spot area difference on four quadrants of four-quadrant photo detector causes the difference of four quadrant output signals, determine the side-play amount of spot center at four-quadrant photo detector, and there be corresponding mathematical relationship with spot center in spot center in the target surface side-play amount with respect to the side-play amount of four-quadrant photo detector, thereby sets up the Mathematical Modeling of four-quadrant output signal and hot spot deviation angle and distance on target surface.

5, the laser target shooting device based on 4 quadrant detector according to claim 4, it is characterized in that: the four-quadrant photo detector output signal is through preposition amplification, the main amplification, then signal being carried out signal through A/D change-over circuit input computer by software handles, calculate spot center deviation angle and amplitude, determine the position of hot spot, and realize that the simulation of laser position shows, ejaculator's achievement shows at target surface.

6, according to claim 1 or 2 or 4 described laser target shooting devices based on 4 quadrant detector, it is characterized in that: except the pairing perpendicular of semi-transparent semi-reflecting lens, whole laser is accepted in the darkroom that system all is in sealing.

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