RU2538336C2 - Vision system - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is referred to the area of images receiving and processing. In the system the signal is delivered through light filters to the surface of cells filled with a substance polarised under action of the controller command for its light flux control. Upon passage through the light filter the light flux diffracts to slots and passes through transparent medium deviating per a certain angle equal to the wave length and coming to a photocell being a control element in the electric circuit, which allows current passing through a branch with the control element by increase or decrease of current or voltage. Identification and survey control are carried out with holographic techniques of identification by forming displays out of semiconductor elements using data on parameters of the sounding signal and information on environmental conditions from the built-in database.

EFFECT: provision of beam control inertia-free system with electroscopic regulating circuit of the signal parameters.

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Description

The invention relates to the field of obtaining and processing images obtained in various ranges of electromagnetic wavelengths.

The object of the invention is a device that recognizes an image obtained in different optical ranges of electromagnetic wavelengths using a number of elements that form the desired type and parameters of the probing signal, and using the principles of holographic processing when receiving a signal.

In technical vision systems (STZ) designed for intelligent robotic systems, in particular for such as location systems for future robotic cars, planet rovers, rescue robots, mapping systems, etc., it is desirable to have developed sensory support. However, the formation of complex sounding signals in different ranges of electromagnetic wavelengths, the creation of multi-beam location systems and pattern recognition is a complex technical task.

Among the existing and promising STZs, devices based on a scanning laser range finder meet the best requirements for on-board systems of mobile robots [1]. High accuracy in determining the coordinates of objects using laser rangefinders is achieved by low divergence of the laser beam. In such a locator, a laser beam is directed to an object through a transmitting optical system. At the same time, a part of the reflected signal is supplied to the photodetector and photomultiplier using a lens and a narrow-band optical filter. The signal from the photomultiplier is measured either by the number of pulses or by the phase delay, it is possible to determine the distance to a specific point of the object. However, to ensure spatial scanning both in azimuth and elevation, it is necessary to use complex electronic and electronic-mechanical systems, both for laser location systems and for radar stations.

There are known developments of antenna arrays whose phase shifters use a plasma cloud to change the phase of a transmitted signal [2]. To date, such devices have not reached the technical level, when it becomes possible their widespread practical application. All of the above devices have minimal response times in comparison with their mechanical counterparts. However, they cannot be applicable in a number of devices, such as STZ, data transmission and reception systems, as well as reconnaissance systems, electronic or optical suppression systems in cases where it is necessary to scan the environment as quickly as possible, to modulate the optical signal when transmitting large amounts of data, to monitor frequencies at which radar stations or information radio lines emit. The usual microwave circuit for constructing a phased array using a separate phase shifter in each discrete element in the optical region is practically impossible, therefore this circuit cannot be used for laser location systems. Laser systems use optical systems to deflect a collimated beam due to natural refraction, as well as the Kerr and Pockels effects, the ferroelectric effect when the beam passes through a refractive medium (calcite, KH ₂ PO ₄ , etc.) [3]. The digital scanning system presented in [4, 5] consists of two main parts: a crystal with natural birefringence (calcite) and an electro-optical crystal with birefringence (KH ₂ PO ₄ ). A suitably oriented birefringent crystal divides the unpolarized light beam into two beams. Rays have linear and mutually perpendicular polarizations. The light beam in accordance with the direction of polarization occupies one of two possible directions. The direction of polarization is determined by applying the appropriate voltage to the transparent electrodes deposited on the crystal. In this case, the longitudinal electro-optical Pockels effect is used. For a three-stage system, two options are possible: for collimated and for converging beams. The option for a collimated beam is simpler, but it has limitations on the number of resolvable output positions of the beam at a given aperture. Higher resolution can be obtained by passing a converging beam through an appropriately designed device and focusing it in the output focal plane. Thus, the best use of the aperture of the deflecting system is obtained, and for a given crystal size, the number of beam positions increases.

Since it is rather difficult to obtain an electric deviation of the light beam at large angles, a device was developed that combines a laser and a cathode ray tube [6, 7]. Laser radiation in a scanning laser exits the cavity with a controlled Q factor, having the desired direction of propagation. The resonator consists of two optically conjugated mirrors, which are reflected in one another by means of lenses inside the resonator. Selective deterioration of the quality factor is carried out by a modified cathode ray tube. First, all types of vibrations are polarized, and a birefringent plate placed inside the resonator creates sufficient elliptical polarization to suppress the vibrations. A crystal (KH ₂ PO ₄ ) is mounted on one of the dielectric mirrors of the resonator, and this mirror simultaneously serves as a target for the deflected electron beam. Elliptical polarization can be locally suppressed by the electric field of charges, which, acting due to the electro-optical effect of the crystal, create an elliptical polarization with the opposite direction of rotation.

However, these circuits are unsuitable or costly for controlling the parameters of the electric circuit in control systems, in electronic warfare tasks, and in some data reception and transmission systems, as this requires the formation of the laser beam itself, as well as a separate subsystem for scanning and controlling the laser beam. Moreover, the achievable changes in the refractive index are insignificant.

The objective of the invention is the creation of a CTZ with a practically inertialess beam control system, the main element of which is an electro-optical scheme for regulating signal parameters, and a new receiving circuit, which allows the use of various processing methods, including holographic ones.

In the proposed device, the formation and modulation of the beam occurs by adjusting the parameters of the electric circuit with an electro-optical circuit, the input signal of which is a programmable signal of a given frequency from a digital processor, and the output is the required phase delay for each aperture radiator of the antenna array or laser scanning system. The use of such a scheme is possible both in continuous and pulsed systems.

The indicated technical result is achieved by supplying a control electric signal to the surface cells from polarizable crystals (“liquid crystals”) transmitting light radiation of a certain wavelength (after the filter), which, being refracted in the optical medium and deflecting through the slits, comes to the photocell with a corresponding delay , where it then passes through the transparencies formed using the matrix of liquid crystals, which, in turn, are obtained using the built-in database of environmental data anovke and objects, after which the signal is compared to a threshold, and concludes that the location of the autonomous robot and the presence of objects in the visual field.

This scheme contains a light source, the radiant flux of which passes through the filters to the surface of the cells, filled with a substance that is polarized by the control signal from the controller. The light diffracts through the slots, deviating at a certain angle corresponding to the wavelength, passes through a transparent refractive medium, enters the photocell (photodiode, phototransistor, photo resistance), which is the control element of the electrical circuit and allows the current of the controlled circuit to flow through the branch where this control element is located , increasing or decreasing the required values of current or voltage and allows you to implement a phase delay circuit for a transmitting array of semiconductor lasers. The receiving circuit of the CTZ contains a set of sensitive elements, a synchronizing device, a correlator, including a matrix of transparencies formed from the cells of polarizable crystals formed using the built-in database of data and a comparison unit. In the aperture of the proposed receiving device, each element of the array (CMOS photocell cell, microbolometer, etc.) is located near the emitter at a certain distance. After the formation of the probe pulse, the CTZ is synchronized using a synchronizing device. The signal from the transmission line contains information about the index of the element that emitted the signal, and the parameters of the pulse, the end time of the pulse, the duration and duty cycle, which are used in the correlator. Transporters are formed in the correlator for pulses coming through the photodetector. The signals passed through the banners enter the comparison unit, where the signal is analyzed. After the comparison block, the calibrated signal enters the processor, where the current position and the presence of unaccounted objects are calculated.

A new set of structural elements, as well as the presence of relations between the parameters allow, in particular, due to the presence of:

- a processor for processing the incoming and issuing a control signal - to ensure the formation of the required probe beam (or several) and the solution of the problem of determining the current position and detection of objects;

- digital controllers - to ensure the formation of a control signal to the surface from polarizable crystals ("liquid crystals") when controlling the beam in the transmitting circuit and creating banners in the receiving circuit;

- lamps and reflective surfaces - to form a uniform light flux over the entire surface with cells from polarizable crystals;

- filters located in front of the surface with cells of polarizable crystals - transmit light with a specific wavelength;

- surfaces with cells of polarizable crystals, which, when polarized, rotate their molecules in such a way that they regulate the luminous flux, - ensure the passage of the luminous flux with a given power and a specific wavelength into the transparent medium of refraction in the transmission circuit and the formation of transparencies for implementing holographic recognition principles ;

- a slit mask, limiting the amount of light flux incident on the photocell, and causing diffraction of this flux on the slit, and the photocell itself, to regulate the current strength in the branch of the electric circuit;

- matrix-type photodetector, providing a signal at the correlator input, - pass reflected pulses through a set of banners to the comparison unit;

- a synchronizing device that generates a signal about the index of the element in the radiating grating for the comparison unit and about the parameters of the probe pulse for the receive-transmit switch and the delay line, - determine the operating time of each banner;

- a database with source information about the environment, presented in a discrete form for the convenience of classification and recognition, - to issue a control signal to the controller forming banners.

By controlling the color and brightness of the image using a graphic image, you can get various changes in the parameters at the input of the controlled circuit, which presents great opportunities for the formation of sounding signals. The successive formation of banners using the delay line, taking into account information about the signal parameters, allows for the invariance of the received image to the angular position of the STZ carrier.

The invention is illustrated by drawings, where figure 1-4 presents one of the possible technical solutions.

Figure 1 presents the functional diagram of the proposed STZ.

STZ consists of a processor, a transmitting device, a receiving circuit, including a synchronizing device, a receiving device, a correlator, a database of the environment and objects.

The transmitting device is presented in figure 2. It includes a part that forms a graphic image, a light system, electro-optical devices for controlling the parameters of an electric circuit, a transmission line, and elements of an active optical array.

The part forming the graphic image 3 consists of a controller 4 of electro-optical devices for controlling the parameters of the electric circuit 6, which are connected to it via a common bus 5.

The light system is a lamp 1 of the visible range of electromagnetic wavelengths (with filament, mercury, LED) and reflective surface 2.

The transmission line 8 serves to transmit and amplify the control signal via buses 7 and 9 to the elements of the active optical array 10, as well as to provide a signal to the synchronizing device.

The elements of the active optical array are semiconductor lasers mounted at various angles to provide inertia-free control of the scanning beam, as well as for multipath scanning.

The main element of the transmitting device is an electro-optical device for controlling the parameters of the electric circuit shown in Fig.3.

The electro-optical device for controlling the parameters of the electric circuit 6 consists of an optical system and an input stage of a controlled circuit.

The optical system consists of a light filter 11, a surface of "liquid crystals" 12 with bus terminals 5 to receive signals from the controller 4, slotted masks 13 and 15, the refractive medium 14.

The input stage of the controlled circuit is part of the controlled circuit of the formation of the probe pulse and contains in addition to the power source photocell 16.

The parameters of the electrical circuit are regulated by supplying light passing through the reflecting surface 2 from the lamp 1 through the filters 11 to the surface of the cells 12 filled with a substance that changes its polarization under the action of a control signal supplied to the terminals 5 of the cell from the controller 4 of the surface 12 for control power of the light flux, which after passing through the filter 11 passes through the slot 13 into the transparent medium 14, deviating at a certain angle corresponding to the wavelength, and getting through the gap 15 photocell 16, which is the control element of the controlled electric circuit of the formation of the probe pulse, which, in turn, allows the current of the controlled circuit to flow through the branch where this control element is located, thereby increasing or decreasing the required current or voltage, as well as allowing a time delay circuit for active optical array elements 10.

Figure 4 presents a diagram of a receiving circuit, including a synchronizing device, a receiving device, a correlator, a database of the environment and objects.

The synchronizing device 17 receives a signal containing information about the index of the element in the emitting lattice (II signal) entering the comparison unit, and about the parameters of the probe pulse (SI signal) for the receive-transmit switch 18 and the delay line 19 for implementing the algorithm of each transparency in the correlator 23.

After switching to the receiving state of the reflected pulses from the elements 21 of the matrix photodetector 20, signals begin to arrive. At the same time, conductivity voltages are supplied to the banners 26, which are semiconductors, through the controller 24 and bus 25 in accordance with the delay time of line 19, which is intended to form a field of view in range. During one review cycle, using the database of the environment and objects 22 through the controller 32 and bus 31 to the control diodes 30, voltage is applied to sequentially generate all possible banners at the current range (via bus 29).

The signals passed through the banners from the elements 21 of the matrix photodetector 20 through the bus 27 enter the comparison unit 28, where the signal is analyzed taking into account the directivity of the element that emitted it. From the comparison unit, the signal calibrated in accordance with the threshold values enters the processor, where the current position and detection of unaccounted objects are calculated.

The present invention will make it possible to equip autonomous robotic complexes, automobiles, aircraft with a fast-acting, vision-invariant system of technical vision with advanced capabilities for controlling a laser beam or several, providing detection of objects falling into the field of view and using holographic principles for recognition with the possibility of topographic referencing and dynamic scene analysis .

Literature

1. Nechaev A.I., Burdygin A.I., Bunyakov V.A. Optoelectronic target designation system. IX scientific and technical conference "Extreme Robotics". SPb .: SPbSPU, 1998.

2. Kalyaev I.A., Kapustyan S.G., Usachev L.Zh. Vision systems based on scanning laser rangefinders. Science is for production. No. 1. 1999 year

3. A.S. No. 1689971 (USSR). A device for forming a map of the area in front of the vehicle. L.Zh. Usachev. BI No. 41, 1991

4. RF patent No. 2193825. A method of processing signals to determine the coordinates of objects observed in a sequence of television images, and a device for its implementation (options). Artsatbanov A.YU .; Bachilo S.A .; Itenberg I.I .; Kalashnikov V.M .; Markov A.L .; Naumov V.V .; Sivtsov S.A .; Fomenko G.A. 2002 year

5. M. Skolnik: Radar handbook, MgGraw-Hill Book Company, b.4, 1970. Translation from English: ed. M.M. Weisbane, M., 1978.

6. Kulcke W., C.J. Harris, K. Kosanke, and E. Max: A Fast, Digital-indexed Light Deflector. - "IBM j. Res. Develop.", 1964, January, v. 8, p. 64-67.

7. Harris T.S., and j. Lipp .: Digital Laser Beam Deflection. - "Laser Focus", 1967, April, v. 3, p. 26-32.

8. Pole R.V., et al .: Selectivity Degenerate Laser Cavity, IBM Walson Res. Center, Tech, Repl, AFAL-TR-67-127. 1967.

9. Fletcher P .: Electro-optical System Rept. 1920, NASA-2439, 1961, October.

Claims (1)

A vision system comprising a processor, a transmitting device that includes a controller, a bus, an electro-optical device for controlling parameters of an electric circuit, including an optical system from a light filter, a surface of "liquid crystals" with terminals for receiving signals from the controller through a bus, gap masks, a refractive medium and an input stage with a photocell of the light system, a transmission line and elements of an active optical array, a receiving circuit, which consists of a synchronizing device, a device VA, containing a database of the environment and objects, a receiving device on a matrix of photocells, a correlator including transparencies on a matrix of semiconductor elements, buses, controllers for controlling the conductivity of banners and a comparison unit, characterized in that the controller is designed to generate a probe beam by command from the processor using a transmitting device, where the probe beam is controlled and its parameters are controlled by adjusting the light flux through the filters on the cell surface filled with a substance polarized by the control signal of the controller and changing the light flux, which, after passing through the filter, diffracts into the slits and passes through the transparent medium, deviating by a certain angle corresponding to the wavelength, and falling onto the photocell (photo diode , phototransistor, photo resistance), which is designed to control the parameters of the electric circuit, including elements of the active optical array, which directly forms while the receiving device is intended for receiving and recognizing the reflected signal using holographic methods of correlation recognition by forming transparencies from semiconductor elements receiving a signal from the synchronizing device about the parameters of the probing signal and a signal with a priori information about the environment from the built-in database and intended to change the parameters of the signal from the photocells of the receiving device when passing through them and after then transferring it to the comparison unit, at the output of which signals calibrated in accordance with the threshold values appear, which are the input to the processor of the vision system, which performs detection, recognition, and topographic location.

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