RU2723692C1 - Autonomous laser coordinate determining system of uav without use of gps/glonass modules - Google Patents

Abstract

FIELD: communication equipment.SUBSTANCE: present invention relates to optical communication and location complexes configured to neutralize attack vectors on an unmanned aerial vehicle (UAV) over radio communication and control channels. Autonomous system for the laser coordinate determination unmanned aircraft comprising a ground navigation station (GNS) and UAV. GNS comprises a computer, a time-to-digital converter, a platform control device with a built-in analogue-to-digital converter, step motors, mechanical rotary system, slow photodiode with built-in amplifier, fast photodiode, amplifier, laser transmitter, NOT element, comparator. Unmanned aircraft comprises emergency control unit with corner reflector. Said computer is connected to time-to-digital converter and rotary platforms control device, which, through step motors connected to it, controls mechanical platform of mechanical rotary system. Laser pulses generated by the laser transmitter are transmitted through the optical system to the angle reflector and reflected from it, are recorded by fast and slow photodiodes, where the signal from the fast photodiode through the comparator, the NOT element and the time-to-digital converter is transmitted to the said computer. Signal coming from slow photodiode via built-in ADC of rotary platforms control device is also supplied to computer, wherein said computer controls laser coordinate determination system.EFFECT: technical problem of the proposed invention is providing UAV with an optical communication channel which is weakly susceptible to radioelectronic interference.1 cl, 2 dwg

Description

The claimed invention relates to complexes of optical communication and location, made with the possibility of neutralizing the attack vectors on an unmanned aircraft (BVS) via radio communication and control channels.

Recently, in the consumer and professional markets, the demand for small-sized (up to 30 kg) multi-rotor systems, which are widely used in solving various problems of remote sensing, aerial photography, reconnaissance, communications, electronic warfare, etc., has sharply increased. In addition, military models are capable of striking air, ground and surface targets. It was the use of miniature DABs for military purposes that led to a qualitative breakthrough in the development of electronic warfare systems to combat them, which, as the conflict in the Syrian Arab Republic has shown, successfully neutralize the threats associated with miniature DSS. The main attack vectors are navigation, control and telemetry transmission systems, and not only can a complete suppression of a certain channel be conducted, but also misinformation. Therefore, the challenge arises of providing the BVS with a communication channel that is weakly prone to electronic interference. Atmospheric optical communication lines (AOLS) are well suited for this, which have proven themselves well when building networks between fixed terminals, but encounter significant difficulties when working with mobile subscribers.

Atmospheric optical communication lines (AOLS) are well suited for this, which have proven themselves well when building networks between fixed terminals, but encounter significant difficulties when working with mobile subscribers.

Despite this, there are several companies on the market that have overcome this technological barrier, for example, MOSTCOM (Russia). Typical speeds achieved in this segment of the AOLS market are about 1 Gbit / s, with a range of about 3-4 km. However, the availability of the optical communication channel in known configurations does not allow implementing the BVS control system based on it.

The prior art unmanned aerial system containing an airborne radar station with avionics designed to generate, emit and receive a radar signal used to detect and track air, sea and ground objects at ranges up to 400 km, operate in the X-frequency range moreover, a passive phased array installed on a two-stage mechanical (in azimuth and roll) electrohydrodrive, which provides, taking into account the radiation pattern width, viewing angles relative to the construction axis of the unmanned aerial vehicle, in azimuth ± 120 °, is used as an antenna unit elevation angle ± 60 °. (RU 187275 U1 02.28.2019).

A disadvantage of the known solution is the low efficiency associated with high exposure to electronic interference.

A prior art aircraft navigation system comprising an aircraft and a ground navigation station is known. Onboard the aircraft are located: inertial navigation system (ANN), radio navigation corrector - satellite navigation system (SNA) and autonomous corrector of ANN data - computing unit for correlation-extreme information processing (CEI). The ground part of the system is made on a personal electronic computer (PC). The coordinate estimates obtained from the flight data and as a result of the accompanying mathematical modeling are combined according to the criteria of homogeneity and belonging to the same general population and are statistically processed. For visualization and subsequent analysis of flight results in dynamics, a block for estimating, analyzing, and visualizing (OAV) the aircraft trajectory in a reference environment in 3D format was introduced. The autonomy, reliability and accuracy of determining the actual values of the coordinates of aircraft navigation (RU 2487419 C1 03/10/2013) are increased.

Also known from the prior art is an optical location system including optically coupled laser transmitters located on the optical axis of the transmitting channel, which forms a probe laser beam, a pilot laser, which forms a control laser beam, beam splitters, a telescope, a Dove prism, a beam deflecting device laser radiation, an output telescope, a horizontal platform with first and second mirrors located on it, rotatable around a vertical axis, three coaxial rotation shafts, optically conjugated third mirrors also located on the optical axis of the receiving channel, the inverse reflective surface of the first mirror, mirror a lens of the receiving telescope, a corner mirror, a combined photodetector, while the second and third mirrors are made with the possibility of synchronous rotation around the horizontal axis, as well as the device alignment, including a rectangular prize mu in the center of the first mirror, rectangular reflective prisms in the centers of the second and third mirrors, a diamond prism with a diaphragm mounted on the output face of the diamond prism, as well as signal processing units, drives, current state sensors and control units of the main optical-mechanical units of the system , central control unit (RU 2292566 C1 01/27/2007).

The disadvantages of the known technical solutions is the inability to use on the BVS.

The closest analogs are an unmanned aerial complex containing aero-aerodrome-based UAVs and a launch ground station containing a mobile platform and a power plant and an UAV flight control unit installed on it. The UAV is made in the form of a two-console wing, on the rotary consoles of which movers are installed. The consoles are made with the possibility of their rotation through 180 ° relative to the longitudinal axis of the wing around the body for the payload. On the platform of the launching ground station, a transmission shaft connected to the gearbox and a launching device mounted using three supports are installed vertically. The starting device contains means for transmitting rotation from the transmission shaft to the UAV, as well as means for fixing and unlocking it at a given rotation speed of the transmission shaft. The supports of the launching device are telescopic with independent adjustment of their length from the control unit for pre-flight correction of the spatial orientation of the unmanned aerial vehicle. The LHC is equipped with a pre-flight automatic static balancing system for an unmanned aerial vehicle (RF 2403182 dated 06/18/2009).

The disadvantages of the closest analogue are the impossibility of using an unmanned aerial vehicle to accommodate the radio-technical complex of radar detection, low noise immunity of control channels of the control unit, low accuracy of determining coordinates.

The technical problem of the claimed invention is the provision of unmanned aerial vehicles (BVS) with an optical communication channel, weakly prone to electronic interference.

The technical result consists in providing the ability to autonomously determine the coordinates of the BVS without the use of GPS / GLONASS modules.

The indicated technical result is achieved in an autonomous laser coordinate determination system for an unmanned aircraft containing a ground navigation station (NNS) and an unmanned aircraft (BVS), while the NNS contains: a computer, a time-to-digital converter, a platform control device with a built-in analog-to-digital converter , stepper motors, mechanical rotary system, slow photodiode with built-in amplifier, fast photodiode, amplifier, laser transmitter, “Not” element, comparator; the unmanned aircraft contains an emergency control unit with a corner reflector, the computer being connected to a time-digital converter and rotary platform control device, which, through the stepper motors connected to it, controls the mechanical platform of the mechanical rotary system; laser pulses generated by the laser transmitter are fed through the optical system to the corner reflector and reflected from it, recorded by fast and slow photodiodes, where the signal from the fast photodiode through the comparator, the element "Not" and the time-to-digital converter enters the mentioned computer; the signal coming from the slow photodiode through the built-in ADC of the rotary platform control device also enters the computer, while the specified computer controls the laser coordinate system.

An additional feature is that the optical system contains a collimator, a polarization beam splitter, a quarter-wavelength λ / 4 plate, a lens with a focal length of 4 cm, and interference filters with a central wavelength of 810 nm and a transmission spectrum width of 10 nm.

The claimed invention is illustrated in the drawings, where:

FIG. 1 - Schematic diagram of a system of autonomous laser coordinates determination of BVS without the use of GPS / GLONASS modules.

FIG. 2 - Optical design of an autonomous laser coordinate system for determining the coordinate system

The claimed invention combines a communication and command transmission system and an autonomous laser coordinate determination system, which operates independently of the on-board equipment of the BVS and all calculations of which are carried out at the ground station. The duplicating optical communication and control channel of the BVS created in this way allows using the BVV in areas of increased radio interference or radio silence, as well as in jamming or compromising satellite navigation systems. As a result, the availability of the communication channel with the BVS increases and can reach 99.9%.

The coordinate determination system (Fig. 1) determines the angular coordinates and the distance to the corner reflector, mounted on the emergency control unit BVS (BAUB), relative to the ground navigation station (NNS). In the process, the system scans the space with a beam in order to determine the angular position of the corner reflector, points at the corner reflector and measures the time of flight of the laser pulse from the ground base station to BAUB and vice versa, due to which the distance from the ground base station to BAUB is determined. Angular coordinates are determined during guidance by the position of the mechanical turntable.

The laser coordinate determination system is controlled from the computer of the ground-based base station (Fig. 1).

The computer is connected via USB to the Arduino Uno and the idQuantique id800 time-to-digital converter. Arduino Uno controls the rotary platforms of the mechanics of a rotary system equipped with stepper motors, the Arduino platform was chosen primarily because of the significant ease of use. For this, the drivers of the A4988 stepper motors operating in the 1/16 step mode are connected to the Arduino Uno.

The stepper motors of the mechanical platforms rotate 1 degree in 100 steps. As a result, 1,600 microsteps fall per 1 degree of rotation of the mechanical platform.

An Arduino Uno ADC is also connected to a slow photodiode with a temporal resolution of better than 1 ms (milliseconds), with a built-in Texas Instruments OPT101P amplifier, which has a rise time of 28 microseconds, which makes it possible to determine the average power reflected by an angular reflector at a ground base station, ( the time between two consecutive laser pulses is 1 μs).

Laser pulses generated by a laser transmitter (laser) and reflected from an angle reflector are detected by the Alphalas UPD300-UP fast photodiode with a temporal resolution of better than 500 psec (picoseconds). The pulses from the detector, having an amplitude of the order of 10 mV, are amplified to an amplitude of the order of 1 V, and are fed to the input of a comparator that generates a logic signal “1” when the reference voltage (2.3 V) and “0” are exceeded if the reference voltage is greater.

Further, the received signal passes through the “Not” element, which reverses the logic levels, and goes to the input of the idQuantique id800 time-to-digital converter.

The idQuantique id800 time-to-digital converter also receives InTop PLS-405/808 laser trigger pulses. A time-to-digital converter allows you to determine the time delay between the laser trigger that fires when a laser pulse is emitted and the pulse from a fast photodiode that occurs after a laser pulse travels from a ground base station to BAUB and vice versa.

The pulses of the InTop PLS-405/808 laser, operating in the mode of generating nanosecond pulses with a duration of 80 ns and a repetition rate of 1 MHz, are fed to the input of the optical system for laser coordinate determination. The optical system allows you to direct the laser beam along the coordinates specified by the mechanical rotary platform, and also receives the reflected signal and divides it between fast and slow photodiodes. The radiation of the InTop PLS-405/808 laser at a wavelength of 808 nm is introduced into the system using the C collimator (CFC-8X-B, Thorlabs) of the optical scheme of the autonomous system for determining the coordinates of the BVS (Fig. 2). Then the radiation passes through the PBS polarization beam splitter and the λ / 4 quarter-wave plate, acquiring circular polarization. After that, the radiation propagates towards the BAUB, and is reflected back from the corner reflector Refl.

Passing through the quarter-wave plate a second time, the radiation becomes linearly polarized, but with a plane of polarization perpendicular to the original, and the radiation is reflected from the polarization divider.

Then, the plane of polarization is rotated using a half-wavelength λ / 4 plate, providing a smooth adjustment of the ratio of the optical power reflected on the second polarizing beam splitter towards the fast APD photodiode and passed to the slow PD photodiode. In this case, the radiation passes through apertures D, lenses L with a focal length of 4 cm and interference IF filters with a central wavelength of 810 nm and a transmission spectrum width of 10 nm FWHM. The optical circuit is mounted using a 30 mm Cage-system (Thorlabs), which allows to provide the necessary rigidity by mounting on a system of steel rails.

Claims (2)

1. A system of autonomous laser coordinates determination of an unmanned aircraft, comprising a ground navigation station (NNS) and an unmanned aircraft (BVS), characterized in that the NNS contains: a computer, a time-to-digital converter, a platform control device with a built-in analog-to-digital converter, stepper motors, a mechanical rotary system, a slow photodiode with a built-in amplifier, a fast photodiode, an amplifier, a laser transmitter, an element "Not", a comparator; the unmanned aircraft contains an emergency control unit with a corner reflector, the computer being connected to a time-digital converter and a rotary platform control device, which, through the stepper motors connected to it, controls the mechanical platform of the mechanical rotary system; the laser pulses generated by the laser transmitter are fed through the optical system to the corner reflector and reflected from it, recorded by fast and slow photodiodes, where the signal from the fast photodiode through the comparator, the “Not” element and the time-to-digital converter enter the mentioned computer; the signal from the slow photodiode through the built-in ADC of the rotary platform control device also enters the computer, while the specified computer controls the laser coordinate system. 2. The system according to claim 1, characterized in that the optical system contains a collimator, a polarizing beam splitter, a quarter-wavelength λ / 4 plate, a lens with a focal length of 4 cm, and interference filters with a central wavelength of 810 nm and a transmission spectrum width of 10 nm.

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