RU2340922C1 - Optical-electronic device with mechanical scanning for imaging - Google Patents

Abstract

FIELD: physics; image processing.

SUBSTANCE: proposed optical-electronic device with mechanical scanning for imaging pertains to instrument making and electronics and is designed for visual observation of underlying surfaces and recording the obtained image in the visible and infrared spectrum ranges. Device comprises an optical system, consisting of an objective and a multi-area "ФПУ", a powered scanning unit with an angle transmitter, the axis of rotation of which is perpendicular to the optical axis of the objective, and an electronic signal processing unit. The device also has a second optical system, consisting of an objective and a multi-area "ФПУ" (with a different range from the first). The first and second optical systems are rigidly mounted in line inside the case of the scanning unit.

EFFECT: increased volume of the information obtained simultaneously in the channels for visible and infrared spectrum ranges, improved quality of the image and simple structure of the device.

4 cl, 2 dwg

Description

The invention relates to optical-mechanical instrumentation and electronic equipment and is intended for a visual review of the underlying surface by scanning the terrain and recording the resulting image in the visible (VD) and infrared (IR) ranges.

From the level of technological development, devices are known for acquiring images of a prospected area, which are described in patents: EP 1391681 A1, class. F41G 3/02, publ. 02/25/04; RU 2137160 C1, cl. G01V 8/00, G02B 26/10, H04N 7/18, publ. 09/10/99; EP 0447080 A1, CL F41G 3/02, F42B 12/36, publ. 09/18/91. Exploration of the area is carried out using optical equipment with registration of the image of the observed surface and the device for decrypting the received image. The video cameras of the reconnaissance unmanned aerial vehicle are used as optical equipment, and the decryption device is a ground receiving station.

Such technical solutions have several disadvantages:

- do not provide operational monitoring of changes in the situation,

- they have limited distance of the observed territory,

- do not allow to obtain an image in several spectral ranges,

- do not allow to obtain an image of a flying area with high resolution with a wide field of view of the underlying surface.

Known optical-mechanical scanning devices for acquiring images of the Earth's surface. The following patents should be attributed to such devices: FR 2585204, cl. H04N 3/08, G02B 26/10, publ. 01/23/87; RU 2123197, class G02B 26/10, publ. 12/10/98; WO 91/02996, CL G02B 26/10, H01J 3/14, publ. 03/07/91; RU 2150725, class G02B 26/10, G02B 27/00, publ. 10.06.00. These devices mainly consist of a scanning unit, an input lens and a photodetector (FPU) connected to an electric signal processing unit that carries information about the image.

The disadvantage of such devices is the low utilization of the scanning unit (mirrors, wedges, etc.) and the presence of aberration due to chromatism, which affects the quality of the generated image.

Optoelectronic devices are also known, described in the book of M. M. Miroshnikov “Theoretical Foundations of Optoelectronic Devices”, Leningrad, Mechanical Engineering, 1977, pp. 66-72. This optoelectronic equipment intended for visual review and registration of the received image is installed on a mobile medium. The main elements of this type of device, selected as a prototype, are an optical system consisting of a lens and a FPU, a scanning unit made in the form of a multifaceted mirror, the axis of rotation of which is perpendicular to the axis of the lens, as well as an electronic signal processing unit. Own movement of the carrier provides scanning along the direction of flight, and a rotating mirror scans the earth's surface across the direction of flight.

The disadvantage of the prototype is the limited information associated with the fact that it does not allow to fix the radiation flux in different spectral ranges. When scanning (rotating) the mirror and a fixed FPU, the image is rotated synchronously with the rotation of the mirror, which leads to image distortion, and to increase its quality it is necessary to install a compensator. In addition, when placing the device on a movable medium, it is necessary to carry out image stabilization during device turns due to carrier oscillations.

The objective of the invention is the creation of an optical-electronic device with a mechanical scan, providing a visual overview of the scanned area and obtaining images of the earth's surface in the visible range (VD) and infrared (IR) by converting the electromagnetic radiation of the underlying surface into an electrical signal that carries the information of the displayed surface with high accuracy with objects located on it.

The technical result of the claimed invention is expressed in an increase in the volume, reliability of the information received, in improving the quality of the generated image and the constructive manufacturability of the device.

The indicated result of the claimed technical solution is achieved in that an optical-electronic device with a mechanical scan for obtaining an image containing an optical system including a lens and a multi-site FPU, a scanning unit with a drive and an angle sensor, the axis of rotation of which is perpendicular to the optical axis of the lens, and an electronic unit signal processing, additionally introduced a second optical system, including a lens and multi-site FPU installed coaxially with the first, while the first and second optical Some systems are located in the housing of the scanning unit and are rigidly fixed in it. One of the optical systems is made for the IR range, and the other for the VD range. These optical systems are made in the form of a modular assembly, and each lens is made of optically conjugated components. In this case, the rotating (scanning) unit is mounted on a gyrostabilized platform so that its axis of rotation is perpendicular to the stabilization plane of the gyrostabilizer.

The causal relationship between the totality of essential features and the achieved result is that

- the introduction of the second optical system and its coaxial installation with the first provide simultaneous image acquisition of the underlying surface in various spectral ranges, thereby increasing the amount of information;

- the placement of the first and second optical systems, consisting of the corresponding lens and FPU, in the housing of the scanning unit and their rigid fixing eliminates the shift of the generated image relative to the photosensitive elements (PSE) of the multi-element FPU VD and IR ranges, as a result of which high accuracy is achieved in combining the generated image both spectral ranges without introducing compensators for image reversal into the VD and IR channels;

- the implementation of the optical systems of the IR and VD ranges in the form of a single structural assembly makes it technologically advanced;

- the placement of the scanning unit on a gyrostabilized platform in the presence of angular oscillations of the carrier ensures the preservation of the scanning geometry of the target beam, i.e. the image is formed without overlapping frames on each other and the formation of gaps between them, as a result, the shape of the registered objects is not distorted and there is no loss of information.

The proposed technical solution is illustrated by drawings:

figure 1 schematically shows a General view of an optical-electronic device with a mechanical scan for image acquisition,

figure 2 shows the functional structural diagram of the inventive device.

On a stabilized platform 1 (see FIG. 1) suspended in a gimbal suspension 2, a scanning unit 3 is installed, the rotation of which is perpendicular to the stabilization plane ZOY of the gyrostabilizer. The rotation of the scanning unit 3 is carried out by the engine 4, continuous information on the angular position of the scanning unit 3 is taken from the angle sensor 5. An electronic communication unit 7 is provided on the housing 6 of the optoelectronic device, which provides control of the drive of the unit 3, switching and communication with the carrier equipment, and the main power supply 8.

Figure 2 shows the scanning unit 3, in the housing of which the VD and IR optical systems are rigidly mounted, each of which includes a lens and a photocoupler. In this case, the VD optical system is the VD range channel, and the IR optical system is the IR range channel.

The VD channel includes a mirror-lens lens, consisting of optical components installed along the optical beam, 9-10-11-12-13-14 and FPU 15, where

9 - lens

10 - mirror lens

11 - a counter-mirror,

12 - lens

13 - gluing lenses

14 is a lens.

The IR channel includes a mirror-lens lens, consisting of optical components installed along the optical beam, 16-17-18-19 and FPU 20, where

16 - mirror

17 - a counter-mirror,

18 is an inclined mirror with a Central hole for installing elements of the VD channel,

19 - lenses.

In the housing of the scanning unit 3 there is an electronic signal processing unit including an electronic unit 21 connected to the output of the FPU 15 and an electronic unit 22 connected to the output of the FPU 20 and equipped with a cooling system (not shown in the drawing). The main power supply unit 8 is connected to the secondary power source 8 ¹ and information is collected from the rotating scanning unit 3 through a mechanical contact collector 23. The processed information of the IR and VD ranges is transmitted from the scanner (from the moving part) 3 to the electronic unit communication 7 using a rotating fiber optic connector 24.

The operation of the optical-electronic device with a mechanical scan to obtain an image is as follows. The scanning unit 3 rotates around the axis OX at a constant speed. In this case, the target beam moves along the terrain in a straight line, forming a frame (scan), consisting of lines formed by a multi-element FPU, in which the number of lines is equal to the number of sensitive elements (cha) FPU. Due to the translational movement of the carrier, each subsequent scan is located in the direction of flight farther than the previous one, providing continuous viewing of the terrain. The speed of rotation of the scanning unit is stabilized with high accuracy so that during scanning there are no gaps or overlays in the “running frame”, the number of lines in the scan is proportionally changed in accordance with the speed and altitude. In the presence of angular oscillations, the scanning geometry of the target beam is not disturbed due to the fact that the scanning unit 3 is located on a stabilized platform 1, the angular oscillations of the carrier do not distort the recorded pattern.

When the scanning node 3 rotates, sections in a strip of terrain are sequentially sighted. The radiation flux reflected from the viewed surface of the earth, passing through the hatch in the body of the onboard carrier, through the lens of the VD channel 9-10-11-12-13-14 focuses on the FPU 15, and focuses through the lens of the IR channel 16-17-18-19 on FPU 20. In this case, the width of the field of view is determined by the instantaneous field of view of the element of the FPU, the number of photosensitive elements in the ruler and the angular scanning speed. The electric signal generated by each element of the FPU is fed to the signal processing unit, namely, from the FPU 15 to the electronic processing unit of the VD signal 21, from the FPU 20 to the electronic processing unit of the IR signal 22. Further, the signal conversion is carried out depending on the flight modes and tasks Based on the flight speed and altitude, a real-time image processing algorithm is selected to address the following issues:

- alignment of signals from photosensitive elements by sensitivity,

- automatic adjustment of the video signal level by contrast and brightness,

- compensation of geometric distortions,

- stitching frames of a multi-line scanning system, while the image frame is a digital image obtained as a result of one scan.

Thus, the obtained high-speed information is transmitted through a rotating fiber-optic connector 24 from a rotating scanning unit 3 to an electronic communication unit 7. From the main amplifiers of the electronic communication unit 7, the signal is transmitted through a fiber cable to the information generation, processing and recording system (SFORI), and automatic media control system (ACS LA) signals are transmitted to the electronic communication unit 7.

The proposed device for image acquisition is implemented in the form of structural blocks, which are complete assembly units (modules), which allows them to be manufactured and configured independently of each other. Structurally, the scanning unit is made in the form of a cast housing made of aluminum alloy with mechanical units and electronic units mounted on it. The shape and dimensions of the blocks are determined by the optical scheme. Optical parts are made of titanium sintered with glass. In addition, for example, DBM85-016-2-2, an angle sensor - disk with optocouplers, FPU (VD) -M-433-f6, FPU (IR range) from SOFRADIR MERCURY LW can be used as an engine for rotating the scanning unit LS10, contact collector - GK-11-7B, rotating fiber-optic connector - CBO-2. The signal processing electronic unit can be implemented using the L1879VM2T processor and programmable logic integrated circuits (FPGA).

For a number of parts, a galvanic coating was applied to protect against corrosion during operation and for a decorative look. In the manufacture of the device, universal equipment is used, universal assembly rigging equipment.

The inventive device provides:

- panoramic shooting around the clock in simple and difficult weather conditions in the horizontal stabilized flight mode, during carrier maneuvers, when flying in mountain conditions;

- replacement of modular units during operation;

- obtaining information in various ranges (VD and IR);

- image acquisition without distortion.

Thus, the relevance of the problem, the result achieved and the manufacturability of the device provide the device with practical application.

Claims (4)

1. An optical-electronic device with a mechanical scan for acquiring an image, comprising an optical system including a lens and a photodetector, a scanning unit with a drive and an angle sensor, the axis of rotation of which is perpendicular to the optical axis of the lens, and an electronic signal processing unit, characterized in that he introduced a second optical system mounted coaxially with the first, while the first and second optical systems are placed in the housing of the scanning node and are rigidly fixed in it. 2. The device according to claim 1, characterized in that one of the optical systems is made in the infrared range, and the other is visible. 3. The device according to claim 2, characterized in that the optical systems of the infrared and visible ranges are made in the form of a modular assembly. 4. The device according to claim 1, characterized in that each of the lenses is made of optically conjugated components.

Images