RU2497062C2 - Combined optic-electronic instrument - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: device includes serially connected laser and optic-electronic scanning system, comprising two crossed anisotropic acoustooptic deflectors and an output optic system, and also a unit of deflector control, outputs of which are connected to inputs of deflector control, and external signals of controlled item start-up and lift-off are sent to its control inputs, a unit of mode selection, to the input of which the external signal is supplied to permit distance measurement, a generator of sync pulses, a unit of modulator control, an optical modulator of resonator good quality, the control input of which is connected with the output of the modulator control unit, an output optical system of a range channel and a polarisation prism unit installed between the first and second acoustooptic deflectors, the second output of which is connected with the input of the optical system of the range channel. The receiving range channel includes serially connected receiving optical system, a photodetecting device and a unit of accumulation of echo signals and range calculation.

EFFECT: reduction of weight and dimension characteristics of an optic electronic instrument with preservation of possibility to measure distance and to observe background and target environment.

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Description

The invention relates to the field of optoelectronic instrumentation, in particular optical sights, and can be used to control moving objects with tele-orientation in the laser beam, when controlling, landing and docking aircraft, guiding ships through narrow or gate bridges, remote control of robotic devices in hazardous areas, etc.

Currently, a combined sighting device is known for guidance, comprising a sighting channel, a laser guidance channel containing sequentially located and optically coupled continuous-wave laser, a laser radiation modulator and a forming optical system, as well as a transmitting laser rangefinder channel and a laser rangefinder receiving channel (Patent RU No. 2375665, priority January 21, 2008, IPC: F41G 3/06, G02B 23/00).

In such sights, devices have a laser guidance channel that uses the principle of teleorientation of a controlled object (UO) in the laser information field-raster, the information axis of which passing through the center of the laser raster is aligned with the line of sight of the target (US Patent 4111383, NKI 244 - 3.13, 09/05/78). The main problem that arises in such systems is the problem of noise immunity, which includes the noise immunity of the optical communication line and the issues of stealth.

The noise immunity of the optical lines of communication “sighting channel of the guidance system - target” and “laser guidance channel - receiver of a controlled object” in such systems is significantly reduced due to the accumulation of smoke from the object’s engine or the formation of a dust cloud when it is launched on the target’s line of sight, which with small side winds lead to both loss of target visibility by the operator and disruption of control of the object with insufficient energy potential of the used laser guidance channel (LCN).

The secrecy of similar systems at the current level of development and equipping of technology with laser radiation detectors practically disappears, and the application of a laser target beam over the target during the entire guidance time gives a lot of time to counter (smoke interference for the control channel, laser countermeasure for the target channel, etc. P.).

An increase in the noise immunity of an LCI is achieved by the fact that for systems with a position-controlled launcher, the laser beam is formed so that the optical axis of the beam is shifted before starting the controlled object, for example, for ground launchers it is raised relative to the line of sight of the target by a certain amount. The magnitude of the displacement remains constant as the object flies, and only when approaching the target at a given range, according to a certain law, this displacement is reduced to zero, that is, the optical axis of the beam is combined with the line of sight of the target. In this case, the laser beam irradiates the target for a short time interval when it is superimposed on the target (Patent RU No. 2267734, priority December 17, 2003, IPC: F41G 7/26, G01S 1/70).

The distance to the target is entered into such a laser guidance channel before the launch of the controlled object. Depending on the value of the range and taking into account the known speed of the controlled object, the equipment calculates the flight time in excess and determines the descent trajectory. Thus, in addition to the LCN, the scope should include a range finder, which increases the dimensions and weight of the sight.

The technical result of the invention is to reduce the overall weight characteristics of the optoelectronic device while maintaining the ability to measure range and observe the phono-target environment.

To achieve the specified technical result in a known optical-electronic device, including a series-connected laser and an optical-electronic scanning system, including two crossed anisotropic acousto-optical deflectors and an output optical system, as well as a deflector control unit, the outputs of which are connected to the control inputs of the deflectors, and on the control inputs of which the external start and exit signals of the controlled product are received, a mode selection block is introduced, the input of which is an external signal range resolution, sync pulse generator, modulator control unit, optical resonator Q factor modulator installed in the laser, the control input of which is connected to the output of the modulator control unit, the output optical system of the rangefinder channel and the polarization prism unit installed between the first and second acousto-optical deflectors, the second the output of which is connected to the input of the optical system of the rangefinder channel, as well as the receiving rangefinder channel, including sequentially remote receiving optical system, photodetector and echo accumulation and range calculating unit, the range output of which is connected to the range input of the deflector control unit, and the synchronization input is connected to the first output of the clock generator, the second output of the clock generator is connected to the synchronization input of the modulator control unit, moreover, the output of the resolution of measuring the range of the mode selection unit is connected to the inputs of the operation permit of the modulator control unit and the deflector control unit ami.

A series-connected CCD matrix and a combined video processing unit, as well as a beam splitter installed between the receiving optical system and a photodetector, the second output of which is connected to the input of the CCD matrix, the second input of the combined video processing unit, is connected to the output range of the block accumulation of echo signals and calculating the range, and the output is connected to an external video monitor.

The applicant and the authors in the patent and scientific and technical literature have not found optical electronic devices (EIA), in which the goal would be achieved in a similar way.

Figure 1 presents a block diagram of a combined optical-electronic device.

Figure 2 presents the timing diagrams of the combined optical-electronic device when measuring range and when pointing a managed object to the target.

The combined optoelectronic device comprises a laser 1 and an optoelectronic scanning system 7 connected in series, a deflector control unit 13, a mode selection unit 21, a clock generator 19, a modulator control unit 20, an output optical system 12 of the ranging channel and a receiving ranging channel 22. The laser 1 includes a laser emitter 2, comprising an active element 3 with a dull resonator mirror, an optical Q-factor of the laser resonator 4, made, for example, in the form of acousto-optical one modulator, and an output mirror 5, and the collimator 6.

The optoelectronic scanning system 7 includes serially connected a first anisotropic acousto-optic deflector 8, a polarizing prism unit 9, a second anisotropic acousto-optic deflector 10, crossed relative to the first deflector, and an output optical system 11. The second output of the polarizing prism unit 9 is connected to the input of the output optical system 12 rangefinder channel.

The deflector control unit 13 includes sequentially connected a block for generating clock signals and raster parameters (BFSiPR) 14, a raster code generator (FCR) 15, an adder 16 and a two-channel frequency synthesizer (DSN) 17, the outputs of which are connected to the control inputs of the acousto-optical deflectors 8 and 10, and also the bias code generator 18. The inputs of the bias code generator 18 are connected to the synchronization outputs of the clock generation unit and the raster parameters 14 and the range output of the echo accumulation unit and distance calculation 25, and the output is connected to the second input of the adder 16.

The receiving rangefinder channel 22 includes a series-connected receiving optical system 23, a photodetector 24, and an echo accumulation and range calculating unit (BECS and VD) 25, the output data bus of which is connected to external devices and to the range input of the deflector control unit 13, and the input synchronization is connected to the first output of the clock generator 19.

The receiving rangefinder channel may further comprise a series-connected CCD matrix 27 and a combined video processing unit 28, as well as a beam splitter prism 26 mounted between the receiving optical system 23 and the photodetector 24. The second output of the beam splitter prism 26 is connected to the input of the CCD matrix 27. The second the input of the combined video processing unit 28 is connected to the range output of the echo storage unit and calculating the range 25, and the output is connected to an external video monitor 29.

The second output of the clock generator 19 is connected to the synchronization input of the control unit of the modulator 20. The output of the control unit of the modulator 20 is connected to the control input of the optical Q-switch of the laser resonator 4. The range resolution output of the mode selection unit 21 is connected to the operation enable inputs of the modulator 20 control unit and the control unit deflectors 13.

In the guidance mode of the controlled object, acousto-optical deflectors 8 and 10 receive control signals from the control unit of the deflectors 13. The continuous radiation of the laser 1 passes with a deviation along one coordinate of the acousto-optical deflector 8, passes without deviation the polarization unit 9 and passes with a deviation along the orthogonal coordinate of the acousto-optical deflector 10 , and after passing the output optical system 11 forms in space a laser information raster for guiding the UO. After anisotropic diffraction by the first deflector, the laser beam changes the polarization state and therefore passes through the polarization prism unit 9 without deviation and enters the second deflector.

In the range measurement mode, the pulsed laser beam of laser 1 passes an acousto-optic deflector 8, to which the control signal from the control unit for deflectors 13 does not arrive, without diffraction and, accordingly, without rotation of the plane of polarization, and the polarizing prism unit 9, is sent through its second output to the output optical system 12 of the rangefinder channel and then sent to the target. The laser echo signals reflected from the target are fed to the receiving optical system 23 and projected by it onto the photodetector 24. At the input of the receiving optical system 23, light waves of the visible range also carry information about the phono-target environment. Light waves of the visible range and laser echoes reflected from the target are separated by a beam-splitting prism 26. Light waves of the visible range are projected onto the CCD matrix 27, where the image of the background-target environment is built.

The operation of the combined optical-electronic device is as follows.

1. Range measurement mode.

When applying to the block selection mode 21 OEP (figure 1) of the external command "Range Measurement" (ID) (figa), the EIA is set to the range. At the output of mode selection block 21, a high-level signal U _{BVR is generated} (Fig.2b)), laser 1 is turned on, and a continuous high-frequency signal from the control unit is fed to the control input of the optical Q-factor of the laser resonator 4, made, for example, as an acousto-optical modulator a modulator 20, disrupting the generation of laser radiation of the laser. The clock generator 19 generates a pair of pulses 1 and 2 U _GSI (Fig.2B)), the repetition frequency of which is equal, for example, 4 kHz. A high-level signal U _BVR allows the passage of synchronization pulses 2 (Fig.2c) from the clock generator 19 to the control unit of the modulator 20, while pauses are generated in the high-frequency signal U _BOOM (Fig.2d)), during which the laser emits short light pulses lasting about 10 ns, the time of appearance of which relative to the front of the synchronization pulse 2 is delayed by about 100 ns and coincides in time with the appearance of synchronization pulses 1 (Fig.2c) of the clock generator 19.

Laser pulses have a polarization that is oriented perpendicular to the plane of the drawing and is shown in FIG. 1 by a dot. The laser pulses pass the collimator 6, pass the deflector 8 without diffraction and without changing the state of polarization, and the prism unit 9, through its second output, are sent to the input of the output optical system 12 of the rangefinder channel. The laser beam at the output of the optical system 12 of the rangefinder channel is aimed at the target.

The high-level signal U _BVR has a duration that provides, for example, the passage of 256 synchronization pulses 2 (Fig.2c) from the clock generator 19 to the control unit of the modulator 20. In this case, the target will be irradiated 256 times with short laser pulses.

The laser echo signals reflected from the target arrive at the receiving optical system 23 and are projected by it onto the photodiode of the photodetector (FPU) 24. The photodiode FPU 24 converts the light signals into electrical pulses, which are amplified in the amplifier of the FPU 24. The output electric pulses of the FPU 24 (Fig. 2d)) implicated noise, U _PD are input to the block accumulation echo and calculate the range storage unit 25. In the echo and calculate the range 25 is "digitized" amplitude mixture received signal / noise ratio, for example, desyatiraz yadnym analog-to-digital converter (ADC) with the clock frequency F _T, of, for example, F _T = 200 MHz, a time ΔT = D _MAX / c, where D _MAX - Maximum measured distance to the target, c - velocity of light. The time ΔT is counted from each synchronization pulse 1, arriving at the block of accumulation of echo signals and calculating the range 25 from the clock generator 19 (pigv).

раз, где N - число излученных световых импульсов. Дальность Д_Ц до цели определяется выражением Д_Ц=М_М×с/F_T, где М_М - порядковый номер цифровой выборки с наибольшим значением амплитуды, отсчитываемый от последнего, например, 256-го импульса синхронизации 1 (на фиг.2в) это третий импульс) генератора синхроимпульсов 19. Полученные цифровые данные дальности до цели поступают на вход дальности блока управления дефлекторами 13, где записываются в память формирователя кодов смещения 18, и поступают на шину данных для записи во внешние устройства. Точность измерения дальности определяется частотой тактирования F_T и, при F_T=200 МГц, равна 0,75 м.The ten-digit code of the amplitude of the signal-to-noise mixture after the first synchronization pulse 1 is recorded in the memory buffer, and then, as the next synchronization pulses 1 arrive, the new data of the signal-to-noise mixture amplitude codes are summed with the previous data. As a result of summing in the memory buffer of the BVES and VD 25, there is a total digital sample of the signal-to-noise mixture U _Σ (Fig. 2e)), in which the signal-to-noise ratio is increased by

times, where N is the number of emitted light pulses. The range D _C to the target is determined by the expression D _C = M _M × s / F _T , where M _M is the serial number of the digital sample with the largest amplitude value, counted from the last, for example, 256th synchronization pulse 1 (in Fig.2c), this the third pulse) of the clock generator 19. The received digital data of the range to the target is fed to the range input of the deflector control unit 13, where it is written into the memory of the displacement code generator 18, and received on the data bus for recording to external devices. The accuracy of the range measurement is determined by the clock frequency F _T and, at F _T = 200 MHz, is 0.75 m.

Light waves of the visible range, carrying information about the phono-target environment, are separated by a beam-splitting prism 26 and projected onto a CCD matrix 27, where an image of the phono-target environment is built. The video signals from the output of the CCD matrix 27 are fed to the input of the combined processing unit of the video signal 28, where the combined video signal is generated. The video signals of the phono-target environment are mixed up with the video signals of the target marks and the video signals of the digital range image, the data of which come from the echo accumulation and range calculation unit 25. The combined video signal from the block 28 is fed to an external video monitor 29, where the background target environment, aim mark, digital image of the range to the target and other symbols that facilitate the observation and tracking of the target by the operator.

After setting the signal U _BVR (Fig.2B)) to a low level, the EIA goes into standby mode of the following external control commands.

2. The guidance mode of the AT on the target.

The guidance mode of the UO on the target does not differ from the algorithm of the EIA described for the prototype.

When applying to the control unit of the deflectors 13 (FIG. 1) an external Start command (FIG. 2g)), the initial parameters of all the blocks included in the control unit of the deflectors 13 are set, and the laser 1 emitting a continuous laser beam is turned on. After a time ΔТ _Р equal to approximately 1 s, an external “Descent” command is generated (Fig.2z)).

When applying to the control unit of the deflectors 13 (Fig. 1) an external “Descent” command after a time T _C , during which the controlled object reaches the initial control range L ₀ , BPSiPR 14 starts to operate in the mode of changing the parameters of the laser raster. During the time interval Δti, it generates codes for the angular sizes of the raster M _K , feature codes for the raster type P _K , the number of lines N _S, and other service commands. Consistently connected with BFSiPR 14 FCR 15 generates binary codes Z _T and Y _T that determine the path of scanning the laser beam in the raster. In FCC 18, vertical displacement (excess) codes Kφ are generated. Conditionally, the nature of the change in the code Kφ is shown in Fig.2i). Thus, the binary codes Z _T and Y _T are supplied to the inputs of the adder 16 from the outputs of the raster 15 code generator and the vertical displacement (excess) codes Kφ from the output of the FCC 18, which vary in time depending on the distance to the target. The adder 16 is made in such a way that at its outputs connected to the inputs of the DSCH 17 codes Z _C = Z _T , Y _C = Y _T + Kφ are formed, which determine the vertical displacement (excess) of the center of the laser raster over the line of sight of the target. Codes Z _C and Y _C filed in the DSCH 17 are converted into time-tunable high-frequency control signals fz _c and fy _c . These signals are fed to the OECS deflectors 8 and 10 7. They determine the dimensions of the laser control raster and the displacement of its center relative to the line of sight of the target by the value h (t).

In FCC 18, vertical displacement (excess) codes Kφ = F (L) are formed so that the linear value of the excess h _{0 is} constant in the time interval T _{C ...} T _P and then decreases, for example, along the decrease curve, presented in the form: h (t) = h ₀ (1-e ^{-t / τ} ), where: τ is a constant that determines the rate of decline, t is the current time from the beginning of the decline. Conventionally, the nature of the change in the linear magnitude of the excess h (t) of the center of the laser raster over the line of sight of the target is shown in Fig. 2i).

After time T _K (Fig. 2i)) after the external “Descent” command was issued, the line of sight of the target coincides with the center of the laser raster, and the UO flies to meet with the target at the estimated time point T _C (Fig. 2i)). BFSiPR 14 generates control commands up to the time T _G > T _C , to take into account the instability of the speed of UO, for example, from weather conditions. Next, the control unit deflectors 13 stops the formation of control signals and LST goes into standby mode of external control commands.

мДж, что обеспечит, учитывая дифракционную расходимость лазерного излучения, измерение дальности около 10 км. При увеличении мощности лазера это значение дальности может быть увеличено.Laser 1 operating in continuous and pulsed modes can be implemented on an active element made of garnet with neodymium and pumped by semiconductor laser diodes. An acousto-optical modulator, for example, a commercially available M3-321M having a control signal frequency of 80 MHz, can be installed inside the resonator. An embodiment of such a laser is described in (V.V. Bezotosny et al. Highly efficient compact Nd ³⁺ : YAG - laser at a wavelength of 1.064 μm, operating in continuous and pulsed modes, with diode pumping and Q-switching by an acousto-optic gate. Quantum electronics, t .35, No. 6 (2005), p. 507-510). Such a laser provides output power in the continuous mode of 1.8 W, and in the pulsed mode at a pulse repetition rate of 5 kHz, the pulse power exceeds 120 μJ with diffraction divergence and pulse duration of about 7 ns. With the accumulation of echo signals from pulses, the equivalent laser power in comparison with a monopulse rangefinder is

mJ, which will provide, taking into account the diffraction divergence of the laser radiation, a range measurement of about 10 km. With increasing laser power, this range value can be increased.

BFSiPR 14, FKR 15, the adder 16 and the clock generator 19 can be implemented, as indicated in the prototype, on the basis of a number of microcontrollers, for example, ATMEL T89C51AC2 containing non-volatile memory, control ports and timers.

The block of accumulation of echo signals and calculation of the range 25, which performs the “digitization” of the amplitude of the received signal / noise mixture, the time synchronous addition of the digital amplitude codes and the measurement of the time interval counted from the last synchronization pulse to the maximum of the digital signal determining the range to the target, can also be implemented on the basis of a number of microcontrollers, for example, ATMEL T89C51AC2, containing, in addition to non-volatile memory, control ports and timers, a ten-bit analog-to-digital eobrazovatel required to convert an analog output signal UPF 24 to a digital code.

It should be noted and additional features of the proposed EIA. Classical pulsed rangefinders, as a rule, contain a solid-state laser implemented on an Nd: YAG crystal, pumped by a solid-state active element by the radiation of flash lamps. As a rule, such range finders have a laser beam divergence at the output of the range finder of approximately 6 × 10 ^-4 rad. The diameter of the laser spot from the range finder in the target plane, located at a distance of 5 km, is 3 m, which imposes a restriction on the spatial resolution of the range finder. The angular divergence of the laser in the proposed LST is almost equal to diffraction and with a light aperture of 18 mm is 10 ^-4 rad. At a distance of 5 km, the diameter of the laser spot is 0.5 m. This significantly increases the spatial resolution of the rangefinder.

Thus, the introduction into the EIA of a mode selection block, a clock generator, a modulator control block, a resonator Q factor optical modulator, a rangefinder channel output optical system and a polarization prism unit, and a rangefinder receiving channel, including a receiving optical system, a photodetector, and an accumulation unit, connected in series echo signals and range calculations with the above relationships allows, due to the laser in two modes - continuous and pulsed, reducing it mass-size characteristics of the opto-electronic device while maintaining the possibility of range measurement and observation phono-target environment.

Claims (2)

1. A combined optical-electronic device, including a series-connected laser and an optical-electronic scanning system, including two crossed anisotropic acousto-optical deflectors and an output optical system, as well as a deflector control unit, the outputs of which are connected to the control inputs of the deflectors, and to the control inputs of which external start-up and exit signals of a controlled product, characterized in that a mode selection block is introduced into it, to the input of which an external signal of resolution range rhenium generator, clock generator, modulator control unit, resonator Q factor optical modulator installed in the laser, the control input of which is connected to the output of the modulator control unit, the output optical system of the rangefinder channel and the polarization prism unit installed between the first and second acousto-optical deflectors, the second output of which connected to the input of the optical system of the rangefinder channel, as well as the receiving rangefinder channel, including a series-connected receiving an optical system, a photodetector and a unit for accumulating echo signals and calculating a range, the range output of which is connected to the range input of the deflector control unit, and the synchronization input is connected to the first output of the clock generator, the second output of the clock generator is connected to the synchronization input of the modulator control unit, and the output the range measurement permission of the mode selection unit is connected to the operation enable inputs of the modulator control unit and the deflector control unit. 2. The combined optical-electronic device according to claim 1, characterized in that a series-connected CCD matrix and a combined video processing unit, as well as a beam splitter installed between the receiving optical system and the photodetector, the second output of which is connected to the receiving rangefinder channel, are introduced with the input of the CCD matrix, and the second input of the combined video processing unit is connected to the range output of the echo accumulation and range calculation unit, and the output is connected to the appearance monitors.

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