RU2410629C1 - Optical sight with tracking range finder - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: proposed sight may be used in controlled weapons guidance systems. It comprises opto-electronic unit accommodating finder channel video transducer and range finder channel, guidance and stabilisation drive, control signal conversion unit, target tracking automatic device, transducers of control signals from drives and aforesaid automatic device, and monitor. Additionally, sight comprises scaling unit, acoustic-optical deflector electronic control unit including thermal compensation unit, adder, two-channel frequency synthesizer, and two-coordinate acoustic-optical deflector arranged between laser radiator and output optical system of range finder channel transmitter. Diametre d of range finder photo receiver LED sensitive sire satisfies the condition d≥2F·φ_m, where F is focal distance of range finder receiving optical system; φ_m is maximum angular error of target tracking by optical sight.

EFFECT: accurate range finding for flying high-speed maneuvering targets thanks to target tracking error compensation in rage finder channel.

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Description

The invention relates to optical sights of guidance systems of guided objects and can be used in air defense fire control systems.

To ensure effective destruction of the target, it is necessary to measure the distance to the target. This is especially important when hitting high-speed air targets that are able to maneuver. In the latter case, it is necessary to measure the current range value.

The optical sight in its composition contains at least two channels - sighting and rangefinder. The sighting channel of modern sights, as a rule, contains a television or (and) thermal imaging system (TS), including the appropriate video sensor (VD) and a monitor for observing the phono-target situation. The use of the vehicle as part of the scope ensures compatibility of the sight with the target tracking machine (RF patent No. 2224206, published July 22, 2002, IPC: 7 F41G 7/26). When measuring a range, the gunner combines the reticle (crosshair) of the sighting channel of the optical sight with the target and includes a rangefinder channel. The task of measuring range is simply solved with a motionless target and a motionless sight carrier. When the carrier of the sight moves, and especially when measuring the distance along a moving and maneuvering target, an angular error appears in aiming the sighting mark of the target channel on the target.

So, for example, for the Cheetah anti-aircraft self-propelled gun (Germany), guidance errors during shooting are 3-4 mrad. For combat vehicles of Tunguska complexes, where more sophisticated algorithms for generating drive control signals have been introduced, this error depends on the gunner’s qualifications and is 0.4-0.6 mrad and 0.2-0.3 mrad for highly skilled gunners with high qualifications (RF patent No. 2217681, published July 19, 2001, IPC: 7 F41G 7/20).

Note that in a number of modern optical sights of control systems with video sensors of the sighting channel, target tracking machines (ASC) are used, in which, after a target is detected by a gunner on the monitor, a tracking strobe is superimposed on the target, and the ASC automatically follows the target with a strobe algorithm and generates signals mismatches - the coordinates of the target relative to the line of sight (V.V. Molebny. Optical-location systems. M: "Engineering", 1981, chapter 4). The output signals of the ACS are fed to the optical sight drives, which deploy the optical sight to reduce the mismatch signals, and thus automatically track the target.

Such automated target tracking systems also have an angular tracking error associated with the angular error of the drives when tracking the target, especially when tracking a moving maneuvering target and when working in motion. The magnitude of this error, depending on the design of the sight and the conditions of use, can be 0.3-1.5 mrad.

To increase the target measurement range, the range finder should have a small angular divergence of the laser radiation. A number of modern range finders have an angular divergence of laser radiation of about 0.6 mrad.

Therefore, in some cases, target tracking errors exceed the angular divergence of the laser radiation of the range finders, and it is impossible to measure the current range to the target in real time.

The technical result of the invention is the provision of measuring the current range to the target in the tracking mode, especially of fast-flying and maneuvering targets.

The technical result is achieved due to the fact that the optical sight contains an optical electronic module (OEM), which houses the optically coupled video sensor of the target channel and the rangefinder channel. The rangefinder channel consists of a transmitting device including a laser emitter and an output optical system connected in series, and a receiving device including a receiving optical system, a photodetector and a range calculator, connected in series. As well as an optical sight, it contains a guidance and stabilization drive, a control signal conversion unit, a target tracking automaton, sensors of drive control commands and an ACS, and a monitor. Moreover, the output of the video sensor of the target channel is connected to the first input of the target tracking automaton, the second input of which is connected to the output of the target range calculator, the video output of the target channel video sensor is connected to the monitor input, and the digital output of the angle tracking error signals for the target is connected to the first input of the control signal conversion unit the output of which is connected to the inputs of the guidance and stabilization drive, the outputs of which are mechanically connected to the optoelectronic module. The outputs of the sensors of the drive control commands and the ACS are connected to the second input of the control signal conversion unit, the third control input of the target tracking automaton and the control input of the laser emitter of the rangefinder channel. At the same time, a scaling unit and an acousto-optic deflector control unit, including a series-connected thermocompensation unit, an adder, a two-channel frequency synthesizer, and a two-coordinate acousto-optic deflector installed between the optically coupled laser emitter and the output optical system of the transmitting device of the ranging channel, are introduced into the optical sight the input of the two-coordinate acousto-optical deflector is connected to the output of the laser emitter, and the output XY acoustooptic deflector is connected to the input of an output optical system. The digital output of the angle error signals of the target tracking automaton is connected to the input of the scaling unit. The outputs of the deflector control unit are connected to the inputs of the two-coordinate acousto-optic deflector. Moreover, the diameter d of the sensitive area of the photodiode of the photodetector of the rangefinder channel satisfies the condition: d≥2F · Ω _M ,

where F is the focal length of the receiving optical system of the rangefinder channel;

Ω _M is the maximum angular error of tracking the target with an optical sight.

The introduction of a series-connected scaling unit and an acousto-optic deflector control unit, as well as a two-coordinate acousto-optic deflector installed between the optically coupled laser emitter and the output optical system of the rangefinder channel transmitting device, connecting the digital output of the angle error signals of the target tracking automaton with the input of the scaling unit, connecting the outputs of the control unit a baffle with inputs of a two-coordinate acousto-optic baffle and select the diameter of the sensitive area of the photodiode d ranging channel photodetector of conditions d≥2F · φ _m where F - focal distance of the ranging receiver channel optical system, φ _m - maximum angular error target tracking optical sight, enabled to provide a measure of the current range to the target in the tracking mode, targets due to the fact that a low-inertia system for deflecting laser radiation from a rangefinder channel is introduced into the sight, eliminating the angular mismatch between the direction to the target and the direction m of laser radiation. The choice of the diameter of the sensitive area of the photodiode of the photodetector of the rangefinder channel in accordance with the newly introduced condition made it possible to increase the field of view of the receiver of the rangefinder channel, ensuring the target is in its field of view for all possible angular errors in tracking the target.

The applicant does not know the optical sights in which the goal would be achieved in this way.

The drawing shows a block diagram of an optical sight with a tracking rangefinder, where

1 - optoelectronic module (OEM);

2 - video sensor of the sighting channel;

3 - rangefinder channel;

4 - transmitting device;

5 - receiving device;

6 - OEM guidance and stabilization drive;

7 - block conversion of control signals;

8 - target tracking automaton (ASC);

9 - sensors of control commands of drives and ACS;

10 - monitor;

11 - block scaling;

12 - block electronic control acousto-optical deflector;

13 - two-channel frequency synthesizer;

14 - adder;

15 - block thermal compensation;

16 - laser emitter;

17 - two-coordinate acousto-optical deflector;

18 - output optical system;

19 - calculator range to the target;

20 - photodetector;

21 - receiving optical system;

22 - gunner.

An optical sight with a tracking range finder contains an optical electronic module (OEM) 1, which houses the optically coupled video sensor of the sighting channel 2 and a rangefinder channel 3, including a transmitting device 4 and a receiving device 5, an OEM guidance and stabilization drive 6, a control signal conversion unit 7 , target tracking machine (ASC) 8, control command sensors (DCU) of drives and ASC 9, monitor (video control device) 10, scaling unit (BM) 11, electronic control unit for acousto-optical deflector 12.

The transmitting device 4 of the rangefinder channel 3 consists of a series-connected laser emitter 16, a two-coordinate acousto-optical deflector 17 and an output optical system 18.

The receiving device 5 of the rangefinder channel 3 consists of a series-connected receiving optical system 21, a photodetector 20 and a distance calculator to the target 19.

The electronic control unit of the acousto-optical deflector 12, in the General case, consists of a two-channel frequency synthesizer 13, the adder 14 and the temperature compensation unit 15.

The drawing conventionally presents the gunner 22.

The output of the video sensor of the sighting channel 2 is connected to the input of the ASC 8. The video output of the ASC 8 is connected to the input of the monitor 10, and the digital output of the ASC 8 is connected to the first input of the control signal conversion unit 7 and the input of the scaling unit 11. The outputs of the sensors of the drive control commands and the ASC 9 are connected to the control input of the ACS 8, the control input of the rangefinder channel 3 and the second input of the control signal conversion unit 7. The outputs of the control signal conversion unit 7 are connected to the inputs of the guidance and stabilization drives OEM 6, the outputs of which th mechanically connected with REM 1. Outputs scaling unit 11 through the electronic control unit 12 connected to the control inputs xy acoustooptic deflector 17.

An optical sight with a tracking rangefinder works as follows.

The gunner 22, having detected the target image on the screen of the monitor 10, moving the joystick for controlling the drives of the DCU 9, sets the speed of pointing the OEM along the angular coordinates and, controlling the drives of the OEM 1, tries to combine the crosshairs on the screen of the monitor 10 with the target. On the monitor screen there is an image of the target capture strobe, which in the initial state, without auto tracking, periodically changes the brightness. When entering the target image inside the tracking gate, the gunner presses the “Capture” button of DCU 9, and the sight switches to the target’s automatic tracking mode, trying to combine the crosshairs of the sight (line of sight) with the target. In auto tracking mode, the image of the target capture strobe on the monitor screen does not change the brightness. The target is inside the tracking strobe, but due to drive errors, it is offset relative to the line of sight by a certain angle. Digital codes of the angular coordinates of the target from the ACS are fed to the first input of the control signal conversion block 7, and also fed to the BM input 11. The control signal conversion block 7 converts them into control command signals of the OEM 6 guidance and stabilization drive, thereby ensuring target retention inside the strobe capture target.

When the sight switches to the automatic tracking mode, it is possible to measure the current range to the target. The gunner presses the button "Current range" DCU 9, while the laser emitter 16 of the transmitting device 4 rangefinder channel 3 generates laser pulses with a given repetition rate. The digital codes of the signals of the angular coordinates of the target from the ACS, received at the input of the scaling unit 11, are converted last, taking into account the conversion factors required for operation, into digital deflector control codes and fed to the inputs of the electronic deflector control unit 12. In it, the input digital deflector control codes are converted in the high-frequency control signals fz and fy, which are fed to the two-coordinate acousto-optic deflector 17 of the transmitting device 4 of the rangefinder channel 3, causing the angular offset the laser beam by a value proportional to the measured angular coordinates of the target. Thus, despite the angular displacement of the target relative to the optical axis of the sight, the laser beam of the transmitting device 4 of the rangefinder channel 3 is aimed at the target.

The laser radiation reflected from the target enters the entrance pupil of the receiving optical system 21 of the receiving device 5 of the rangefinder channel 3 and focuses on the photodiode of the photodetector 20, causing an electric pulse to appear at its output, delayed relative to the emitted laser pulse for a time proportional to the distance to the target. The range calculator to the target 19 of the receiving device 5 of the ranging channel 3 measures this time interval and generates a digital range code, which can be converted by the ACS into a video signal and displayed on the monitor in the form of a digital inscription. A digital range code can be supplied to the fire control computer for making appropriate decisions.

. Его проекции на координатные оси x и y в ТС равны φx и φy.The scaling unit 11 couples the measured angular coordinates of the target and the values of the digital deflector control codes to ensure that the angular displacement of the laser radiation of the rangefinder channel is equal to the values of the measured angular coordinates of the target. Let the magnitude of the angular coordinate vector of the target relative to the crosshair of the sight, measured by the ASC, equal

. Its projections on the coordinate axes x and y in the TS are equal to φx and φy.

The module of the vector of angular coordinates of the target can be written in the form:

,

,

where ho is the magnitude of the target offset in the focal plane of the input lens of the video sensor of the target channel having a focal length Fo. Otherwise, linking the magnitude of the angular displacement of the target in the focal plane of the input lens of the video sensor of the target channel and the value of the digital code of the angular coordinates of the target at the output of the ACS, we can write: φc · Ko = Dc,

where Ko is the ACC proportionality coefficient,

Dc is the numerical code of the target position, shifted by an angle φc relative to the line of sight. The code Dс is generated at the output of the ACS and, therefore, it is equal to

The electronic control unit for the acousto-optical deflector 12, in the simplest case, consists of a two-channel frequency synthesizer 13. When a two-coordinate acousto-optic deflector 17 is made of paratellurite single crystal, the deflector scanning angle can be 3 degrees when changing the high-frequency control signals fz and fy in the frequency range 64-96 MHz. The center frequency of high-frequency signals is 80 MHz. At this frequency, the direction of the laser beam at the output of the rangefinder channel 3 is collinear to the optical axis of the sight. The time required for the laser beam to switch from one angular position to an arbitrary other by the deflector is no more than 20 μs.

The electronic control unit of the acousto-optical deflector 12 can be implemented, for example, on two digital microcircuits of the frequency synthesizer AD9851. When using a 13-bit control input on each channel of the synthesizer, the deflector provides an angular displacement of the laser beam at its output equal to 1.35 arc seconds per unit of the control command supplied to the input of the control unit.

The deflection angle γd of the laser beam at the output of the transmitting device 4 of the rangefinder channel 3 can be represented by the expression:

γd = Cd · Da · Gp, where

Cd is the joint coefficient of proportionality for the frequency synthesizer and acousto-optical deflector;

GP - the angular increase in the output optical system 18;

Da is the value of the control code applied to the input of the frequency synthesizer.

In the present invention, the angular increase in the output optical system can be from 1/2 to 1/8, depending on the tasks. To ensure the equality of the angular displacement of the laser radiation of the rangefinder channel and the measured angular coordinates of the target, i.e. φc = γd, we determine the transfer coefficient of the scaling unit 11 in the form: Kbm = Da / Dc = 1 / (Cd · Co · Gp).

The dependence of the angle of deviation γd of the laser beam at the output of the transmitting device 4 of the rangefinder channel 3 is more complete, taking into account the operating temperature TT of the optical sight, can be represented by the expression: γd = Kd · Da · Gp + Kt · ΔT · Gp,

where KT is the temperature coefficient, approximately equal to 10 ^-3 ;

ΔТ = (TT-25 ° C).

When operating the sight in a wide temperature range, especially with a very narrow laser beam of the rangefinder channel, the influence of temperature should be taken into account.

The electronic control unit for the acousto-optical deflector 12 consists in this case of a two-channel frequency synthesizer 13, an adder 14 and a thermal compensation unit 15. The thermal compensation unit 15 should generate a digital signal D _T = -Kt · ΔT · Gp at the output. After adding the signals Dt and Da in the adder 14, the influence of temperature on the scanning angle is eliminated. The implementation of the function of summing codes and generating a signal Dt is easily implemented on the basis of modern microprocessors and temperature sensors, for example, AD22100 ST.

In the present invention, the diameter d of the sensitive area of the photodiode of the photodetector device of the rangefinder channel should be increased to a value of d≥2F · φ _M ,

where F is the focal length of the receiving optical system of the rangefinder channel,

φ _M - the maximum angular error tracking the target with an optical sight.

This is necessary for receiving laser pulses reflected from the target when the target is angularly displaced relative to the optical axis of the sight. Let us evaluate the diameter of the photodiode for the following conditions: F = 200 mm, φ _M = 5 ang. min The diameter of the photodiode is 0.58 mm. Photodiodes actually produced by the industry, designed to receive short laser pulses, for example, by HAMAMATSU, have a number of diameters of photosensitive sites, including 0.5 and 1.0 mm.

The use of new elements and connections favorably distinguishes the proposed optical sight, since it provides the measurement of the current range to the target in tracking mode, especially of fast-flying and maneuvering targets, and when the sight carrier moves due to compensation in the range-finding channel of angular errors of tracking the target.

Claims (1)

An optical sight with a tracking rangefinder, comprising an optical-electronic module, in which a video sensor of the sighting channel and a rangefinder channel are located, consisting of a transmitting device including a connected laser emitter and an output optical system, and a receiving device including a series-connected receiving optical system, a photodetector and target range calculator, as well as guidance and stabilization drive, control signal conversion unit, target tracking automat, com sensors управления control of the drives and the target tracking automaton and a monitor, the output of the target channel video sensor being connected to the first input of the target tracking automaton, the second input of which is connected to the output of the target range calculator, the video output of the target tracking automaton is connected to the monitor input, and the digital output of the machine’s angular error signals target tracking is connected to the first input of the control signal conversion unit, the output of which is connected to the inputs of the guidance and stabilization drive, the outputs of which are mechanically inens with an optoelectronic module, the outputs of the sensors of the drive control commands and the target tracking automaton are connected to the second input of the control signal conversion unit, the third control input of the target tracking automaton and the control input of the laser emitter of the rangefinder channel, characterized in that the scaling unit is connected in series , an electronic control unit for an acousto-optical deflector, including a series-connected thermal compensation unit, an adder, two-channel synt A frequency meter and a two-axis acousto-optic deflector installed between the laser emitter and the output optical system of the transmitting device of the rangefinder channel, while the input of the two-coordinate acousto-optical deflector is connected to the output of the laser emitter, and the output of the two-coordinate acousto-optic deflector is connected to the input of the output optical system, the digital output of the angle signals errors of the target tracking machine is connected to the input of the scaling unit, the outputs of the electronic control unit I acoustooptic deflector connected to inputs xy acoustooptic deflector, the diameter d of the sensitive area of the photodiode ranging channel photodetector satisfies the condition d≥2F · φ _m
where F is the focal length of the receiving optical system of the rangefinder channel;
φ _m - the maximum angular error tracking the target with an optical sight.