RU2516376C2 - Device of laser finding of specified space area - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention may be used in measurement equipment, systems of prevention of vehicles collision, navigation devices and systems of security alarm. The device comprises a control unit 3, a transmitting optical system 7, 8 with a radiation field 13, a receiving optical system 9 with a field of vision 14, made in the form of a cylindrical lens, in the focal plane of which there is a photodetector 6. The sensitivity area is formed by crossing of the field of radiation 13 and the field of vision 14. The device is equipped with a convex conical mirror 11, placed upstream the transmitting and receiving optical systems. The transmitting optical system is made of n identical pairs of perpendicularly crossed cylindrical lenses with matching main optical axes and focal planes, and also from n pulse laser sources of light installed in focal planes of appropriate pairs of cylindrical lenses arranged evenly along the circumference, in the centre of which there is a receiving optical system with the main optical axis, matching with the axis of symmetry of the mirror and parallel to the main optical axes of pairs of cylindrical lenses.

EFFECT: increased quantity of sources of light serviced by one photodetector, compact arrangement of light sources, giving the shape of cone to the sensitivity zone.

2 cl, 3 dwg

Description

Technical field

The invention relates to measuring equipment, and in particular to optical (laser) locations, and can be used in measuring equipment, vehicle collision avoidance systems, in navigation devices and in alarm systems.

State of the art

Laser location means the operating mode of a laser locator, which includes an overview of a given area of space (in general, for all measured coordinates), processing reflected signals, deciding on the presence or absence of objects in the entire zone as a whole, or indicating specific resolution elements in which they are present.

A device for optical location according to the author's certificate of the USSR No. 1649270, class. G01C 3/08, 1988, authors: Chabdarov Sh.M., Feoktistov A.Yu., Breidburd A.I., Rakhimov R.Kh., containing a pulse transmitter, a space review unit, a transponder, an information processing unit, an indicator range and recognition. The specified device provides automatic recognition and tracking of a moving object equipped with a transponder made in the form of an encoded matrix and a matrix of corner reflectors.

The disadvantage of this device is that it can be used only when detecting and tracking pre-prepared objects.

Known meter of small distances, according to the author's certificate of the USSR No. 491029 dated 06/04/1973, IPC G01C 3/00, authors: Evtikhiev N.N., Mamontov O.A., containing a space review unit including transmitting and receiving optical systems with intersecting fields view, light source, photodetector and computing device (recorder). The transmitting optical system is made in the form of a collimator with a narrow radiation field. The field of view of the receiving optical system is characterized by a significantly wider viewing angle. The narrow radiation field of the transmitting optical system provides a sufficiently high accuracy of measuring the distance to the observed object due to the significant density of light energy and allows the system to have high spatial resolution.

The disadvantage of this device is that the wide field of view of the receiving optical system increases the amount of received background noise.

As a prototype, a device was selected for laser location of a given region of space, described in RF patent No. 2 375 724 of March 24, 2008, IPC: G01S 17/02 Vyshivany I.G., Galchenko B.I., Izrailev B.I., Perevalov A.I., Tkach A.Ya. The device comprises a control unit connected to a pulsed laser light source and a photodetector, transmitting an optical system containing a lens in the form of a cylindrical lens, in the focal plane of which a light source is installed, a receiving optical system in which focal plane a photodetector is installed, while the sensitivity zone is formed by the intersection radiation fields of the transmitting optical system; and fields of view of the receiving optical system. In addition, to expand the area of space in which the laser location is conducted, the transmitting and receiving optical systems are mounted on a panel that can change the spatial orientation.

As a disadvantage of the prototype, it can be noted that to expand the area of space in which the laser location is carried out, a mechanical orientation drive is introduced. This complicates the device and increases its overall dimensions.

Disclosure of invention

The objective of the invention is to expand the region of space in which the laser location per unit of time is carried out, simplifying the design of the device and reducing its size.

The technical result consists in making the sensitivity zone cone-shaped, increasing the number of light sources served by one photodetector, and compactly arranging the light sources around the photodetector.

The specified technical result is achieved by the fact that the device for laser location of a given area of space contains a control unit, the output of which is connected to a pulsed laser light source, and the input to the photodetector. The device also contains a transmitting optical system with a radiation field, made in the form of a cylindrical lens, in the focal plane of which a light source is installed, a receiving optical system with a field of view, made in the form of a cylindrical lens, in the focal plane of which a photodetector is installed. In this case, the sensitivity zone is formed by the intersection of the radiation field of the transmitting optical system and the field of view of the receiving optical system. According to the invention, the device is equipped with a convex conical mirror placed in front of the transmitting and receiving optical systems. The transmitting optical system is composed of n identical pairs of perpendicularly crossed cylindrical lenses with matching main optical axes and focal planes. Pairs of cylindrical lenses are placed evenly around a circle in the center of which a receiving optical system is fixed with a main optical axis that coincides with the axis of symmetry of the mirror and parallel to the main optical axes of the pairs of cylindrical lenses of the transmitting optical system.

In addition, the photodetector is equipped with a narrow-band filter that transmits light with a radiation wavelength of pulsed laser light sources.

The use of a narrow-band filter allows to improve the sensitivity of the device by cutting out the background radiation signal (interference) from the spectrum of the recorded signal, which increases the signal-to-noise ratio.

Simplification of the design is achieved by using a single photodetector for n light sources. Reducing the transverse dimensions is achieved by placing light sources around one photodetector. The expansion of the controlled area of space is achieved by organizing the sensitivity zone in the form of a figure similar in shape to a conical surface by reflecting from the mirror the field of view and the radiation field created by n light sources.

The fact that the device is equipped with a convex conical mirror located in front of the transmitting and receiving optical systems allows you to increase the number of light sources per one photodetector.

The transmitting optical system is composed of n identical pairs of perpendicularly crossed cylindrical lenses with matching main optical axes and focal planes. Pairs of cylindrical lenses are placed evenly around a circle in the center of which a receiving optical system is fixed. This allows a compact arrangement of light sources around the photodetector.

Pairs of cylindrical lenses are placed evenly around a circle in the center of which a receiving optical system is fixed with a main optical axis that coincides with the axis of symmetry of the mirror and parallel to the main optical axes of the pairs of cylindrical lenses of the transmitting optical system. This allows you to give the sensitivity zone a conical shape.

Brief description of figures and drawings.

The proposed laser location device for a given area of space is illustrated by the drawings:

Figure 1 is a simplified diagram of a device with six pulsed laser light sources (n = 6).

Figure 2 shows the device in cross section AA.

On figa presents the configuration of the sensitivity zone for three pulsed laser light sources (n = 3).

On figb - for four sources (n = 4).

On figv - for six sources (n = 6).

On figg - for eight sources (n = 8).

Embodiments of the invention

As shown in figure 1, inside the cylindrical body 1 with a translucent window 2, a control unit 3 is placed, connected via cables 4 to n pulsed laser light sources 5 (for example, laser diodes) and a photodetector 6 (for example, a photodiode), figure 1 . The light sources 5 are connected to the outputs of the control unit 3, and the photodetector 6 to the input of the control unit 3.

Each of the n point laser light sources 5 is mounted in a single focal plane of the respective cylindrical lenses 7 and 8. The combination of n pairs of lenses 7 and 8 form a transmitting optical system. In this case, the main optical axes of the lenses 7 and 8 of each pair coincide, and their planes, in which the focal length tends to infinity, are perpendicular (the lenses are perpendicularly crossed).

The pairs of lenses 7 and 8 and the associated light sources 5 are placed evenly around a circle in the center of which is placed a receiving optical system 9 (for example, a lens with spherical lenses), Fig.2.

In the focal plane of the receiving optical system 9, a photodetector 6 is installed. Moreover, in the focal plane of the system 9, in front of the photosensitive area of the photodetector 6, a narrow-band filter 10 can be installed that transmits light only with a certain radiation wavelength, as from light sources 5.

A convex conical mirror 11 is placed in front of the transmitting optical system 7, 8 and the receiving optical system 9. The mirror 11 is oriented by its reflecting surface in the direction of the output apertures of the lenses 7, 8 and the input aperture of the receiving optical system 9. The main optical axis of the system 9 coincides with the axis the symmetries of the mirror 11, and the main optical axis of the pairs of lenses 7.8 parallel to it.

1, the dashed line with the letter Xc shows the main optical axis of the lens 9, and with the letters X1 and X2 the main optical axes of two pairs of lenses 7 and 8.

The sensitivity zone 12 is formed by the intersection of the radiation field 13 of the transmitting optical system 7 and 8 and the field of view 14 of the receiving optical system 9. In Fig. 1, dotted lines show the path of the rays from the light sources 5, which limit the radiation field 13 of the transmitting optical system 7 and 8, and a dash-dot line with two points - the path of the rays to the receiving optical system 9, which limit its field of view 14.

The radiation from the light source 5, falling on a cylindrical lens 7, is formed in the form of a flat diverging petal. The second cylindrical lens 8, installed after the lens 7, forms the incident radiation in the form of plane-parallel light rays. The output beam of light is flat. Figure 2 shows the arrangement of pairs of lenses 7.8 around the circumference, in which the output radiation 13 of the transmitting optical system 7 and 8 is formed in the form of a side surface of a regular n-sided prism, the axis of which coincides with the axis of symmetry of the conical mirror 11 (figure 1 ) The radiation thus formed forms a field of view 13, which, reflected from the surface of the mirror 11, unfolds into a complex geometric figure similar to a conical surface. At the same time, the field of view 14 formed by the receiving optical system 9 and the mirror 11 almost completely overlaps with a part of the radiation field 13 represented by a complex geometric figure similar to the conical surface shown in FIG. 3.

The half-angle α at the apex of the conical mirror 11, the viewing angle β of the receiving optical system 9, are selected based on the required configuration of the sensitivity zone 12.

The number n of light sources 5 can be selected based on the requirements for obtaining a certain configuration of the sensitivity zone 12, as well as the illumination level of the detected object 15. The illumination level is selected based on the sensitivity of the photodetector 6, the larger the number n, the less sensitive the photodetector can be used (for other conditions being equal).

The operation of the device is as follows.

Block 3 generates a signal for alternating switching on of pulsed laser light sources 5, which is transmitted via cables 4 to their inputs. Moreover, the emission time intervals of adjacent pulses do not overlap.

Laser radiation from a working light source 5 is formed by a pair of lenses 7 and 8 and a mirror 11 in the radiation field 13, which propagates through a translucent window 2 into the surrounding space. Part of this radiation 13, reflected from the detected object 15, located in the sensitivity zone 12, enters through the window 2 back into the housing 1, is reflected from the mirror 11 and enters the input aperture of the receiving optical system 9.

The optical system 9 focuses this radiation on the photosensitive area of the photodetector 6, which transforms the light radiation into an electrical signal transmitted to block 3 via cables 4.

In block 3, according to the established algorithm, the fact of finding the object in the sensitivity zone 12 is recorded. The fact that the object 15 is located is recorded, for example, when the signal detected by the photodetector 6 exceeds a predetermined threshold value.

Additionally, in block 3, the distance to the detected object 15 can be estimated by measuring the time interval between the start of the radiation of the light source 5 and registration by the photodetector 6 of the arrival of the radiation wave front reflected from the object 15. In this case, the duration of the radiation pulses of the light sources 5 should be minimal.

In addition, in block 3, the angular position of the object 15 can be estimated. It is determined as follows. The light sources 5 alternately emit laser light. In this case, the radiation time periods between the light sources 5 do not intersect. When the object 15 enters the sensitivity zone 12, the light reflected from the object 15 from the source 5 used at that moment in time enters the optical system 9 and is registered. The sector of location of the object 15 is determined depending on where the radiation field 13 is directed from the given light source 5.

In our available sources of information, no technical solutions have been found that together contain features similar to the distinguishing features of the proposed laser location method. Therefore, the invention meets the criterion of "inventive step".

Claims (2)

1. The laser location device of a given region of space, containing a control unit transmitting an optical system with a radiation field in the focal plane of which a light source is installed, a receiving optical system with a field of view made in the form of a cylindrical lens in the focal plane of which a photodetector is installed, while the sensitivity zone is formed by the intersection of the radiation field of the transmitting optical system and the field of view of the receiving optical system, characterized in that the device is equipped with a convex conical With a mirror located in front of the transmitting and receiving optical systems, the transmitting optical system is composed of n identical pairs of perpendicularly crossed cylindrical lenses with coinciding main optical axes and focal planes, as well as of n pulsed laser light sources connected to the outputs of the control unit installed in matching the focal planes of the corresponding pairs of cylindrical lenses, the pairs of cylindrical lenses are arranged uniformly around a circle, in the center of which a receiving I optical system with the main optical axis coincides with the axis of symmetry of the mirror and parallel to the main optical axes of the pair of cylindrical lenses of the transmitting optical system. 2. The laser location device for a given region of space according to claim 1, characterized in that the photodetector is equipped with a light filter that transmits light with a radiation wavelength of pulsed laser light sources.

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