RU2575318C1 - Method to measure distance to objects, their angular coordinates and mutual location and device for its realisation - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: method to measure the distance to objects, their angular coordinates and mutual location includes radiation in multiple directions, covering in conjunction the field of view and forming a matrix of adjacent optical channels, a certain angular direction is put in accordance with the optical channel, and the distance to the point of the object is calculated in the optical channels in turns in accordance with the specified sequence. At the same time in the device, which realises the method, axes of radiation of laser radiators that generate the matrix of the lasers, are serially turned in azimuth and height by the laser beam intensity divergence angle.

EFFECT: increased efficiency of laser scanners due to the exclusion of optic-mechanical scanning.

2 cl, 1 dwg

Description

The invention relates to measuring technique and can be used to simultaneously measure the distance to objects in the field of view, their angular coordinates and relative position.

A known method of detecting objects, measuring speed, range and angular coordinates, consisting in radiation in the direction of the field of view of the light pulse, for example, using infrared LEDs and detecting reflected light pulses, for example, using photosensitive elements [1]. When a single light pulse is emitted from objects in the field of view located at different angular coordinates and different distances, many light pulses are reflected, which are focused and detected by photosensitive elements. The position of the photosensitive element to which the reflected light pulse arrives determines the angular coordinates of the object in the field of view, from which the signal corresponding to the detected light pulse is received. The light pulse, due to the Doppler effect, when reflected from a moving object, changes its duration - increases if the object moves away, and decreases if the object approaches, while the carrier frequency and the modulation frequency of the signal change. A change in the carrier frequency upon reflection from a moving object leads to a change in the duration of the reflected light pulse. The signals from the reflected light pulses detected on the photosensitive elements are digitized. The disadvantage of this method is the limited field of view due to the narrow radiation pattern.

Known faceted optoelectronic systems, the field of view of which is blocked by many optical channels, consisting of a lens and a radiation receiver [2]. Such systems have high speed, but do not provide a measurement of the distance to the object.

The known prototype method of ground-based laser scanning, which consists in the direction of laser pulsed radiation with a small angle of divergence to objects, scanning with laser radiation a field of view using an optical-mechanical system with simultaneous measurement of the angular coordinates of directed radiation, receiving (detecting) reflected pulses, digitizing the received signals , calculating the distance to the object from the time of arrival of pulses for each angular direction and the formation of a cloud of points that determine the angular coordinates and range of each reflecting area (point) of the object. The method is implemented in devices of ground-based laser scanners [3]. The disadvantage of this method is the low speed due to optical-mechanical scanning.

The purpose of the proposed method for measuring the distance to objects, their angular coordinates and relative position and device for its implementation, is to improve performance when forming a cloud of points that determine the angular coordinates and the distance of each reflecting area of the object.

This goal is achieved by the fact that in the method of measuring the distance to objects, their angular coordinates and relative position, which consists in emitting laser radiation pulses in the direction of the field of view, detecting reflected pulses, digitizing the received signals, calculating the distances to the points of objects in the field of view while measuring angular direction to these points and transmitting the results of measurements and calculations to external control devices, the object field of view is irradiated in many directions, overlapping a plurality of field of view and forming a matrix of adjacent optical channels, wherein each optical channel is assigned a specific angular direction and the distance to the object point calculated in optical channels alternately in accordance with a predetermined sequence.

This goal is achieved by the fact that in a device that implements a method of measuring the distance to objects, their angular coordinates and relative position, containing a laser emitter, a receiving optical system, a radiation receiver, a laser radiation control device, an analog-to-digital converter, a processor, an external control device, a laser emitter formed as a matrix of lasers, lasers sequentially deployed axis azimuth in the angular field W _α and adjustment in the angular field W _h on the divergence angle of the laser and radiation θ, the number of elements in the array in azimuth equal to n _α = W _α / θ, height n _h = W _h / θ, and a radiation control apparatus and a laser processing simultaneously connected clock generator.

The essence of the invention is illustrated in the drawing, where: 1 - laser array, 2 - section of laser beams in the space of objects, 3 - receiving optical system, 4 - radiation receiver, 5 - laser radiation control device, 6 - clock generator, 7 - analog-to-digital converter.

The matrix of lasers is an assembly of semiconductor lasers (laser diodes) operating in a pulsed mode. The receiving optical system consists of a wide-angle lens, the angular field of which covers the field of view, and a condenser that transfers the radiation flux to the radiation receiver. Low-inertia detectors — PMTs or avalanche photodiodes — can be used as a radiation receiver. The laser radiation control device includes standard drivers that provide the creation of series (packs) of a certain number of laser pulses, the synchronizing pulse generator creates a time reference for the emission of laser pulses and a clock signal used to generate radiation pulses synchronous with the connection sequence of the laser diodes.

The device operates as follows. Using the laser radiation control device, a radiation mode is created in which the lasers sequentially (row by row of the matrix) create bursts of pulses of short duration. Each burst of pulses is sent in a certain direction in accordance with the step in azimuth (along the line) and in height (along the frame). The interval between pulses in a packet should be no less than the time that radiation passes to the object and back. The laser pulses reflected from the object are received by the optical system, converted by the radiation receiver into an electrical signal, which is digitized and fed to the processor. The bursts of pulses are spaced in time, due to which they are separately received in each direction of radiation. Based on the arrival time of each reflected pulse in the packet (the time interval between the emitted and received pulses), the processor calculates the distance to the object, the calculation results are averaged, and the distance to the object in the given direction is determined, which is specified by a specific laser (laser number in the matrix). Thus, for each scanning point, spatial coordinates (range, azimuth and elevation angles) are determined, mechanical scanning is not performed, but a wide field of view is viewed. The proposed technical solution can be defined as a “facet laser scanner” in connection with combining the facet principle of constructing an optical system and the principle of constructing a laser scanner.

Information sources

1. A method for detecting objects, measuring speed, range and angular coordinates and a device for its implementation (RU 2521203, auth. Bardin Anton Vladimirovich, Ozerov Veniamin Petrovich, Metkin Nikolai Pavlovich, Filonov Oleg Mikhailovich, Kirshina Irina Anatolevna.

2. A device for detecting and measuring the azimuthal angle of light-emitting pulsed objects (RF patent No. 2494343 from 04/10/2012, auth. Solomatin VA).

3. Seredovich V.A. Ground Laser Scanning: Monograph / V.A. Seredovich, A.V. Komissarov, D.V. Komissarov, T.A. Shirokova. - Novosibirsk: SSGA, 2009 .-- 261 p., P. 9.

Claims (2)

1. The method of measuring the distance to objects, their angular coordinates and relative positions, which consists in emitting laser radiation pulses in the direction of the field of view, detecting reflected pulses, digitizing the received signals, calculating the distances to the points of objects in the field of view while measuring the angular direction to these points and transmitting the results of measurements and calculations to external control devices, characterized in that the object in the field of view is irradiated in a variety of directions, overlapping in aggregate field of view and adjacent optical channels forming a matrix, and each optical channel is associated with a certain angular direction, and the distance to the point of the object is calculated in the optical channels in turn in accordance with a given sequence. 2. A device for measuring the distance to objects, their angular coordinates and relative position, containing a laser emitter, a receiving optical system, a radiation receiver, a laser radiation control device, an analog-to-digital converter, a processor, an external control device, characterized in that the laser emitter is made an array of lasers, lasers sequentially deployed axis azimuth in the angular field W _α and adjustment in the angular field W _h at an angle laser divergence θ, the number of elements in the matrix azimuth equal to n _α = W _α / θ, height n _h = W _h / θ, and a laser emission control apparatus and a processor connected simultaneously generator clock pulses.