RU2768244C1 - System of high-precision local 3d - positioning of water vehicles for navigation and maneuvering on dangerous sections of inland waterways - Google Patents

Abstract

FIELD: navigation.

SUBSTANCE: invention relates to means for ensuring navigation and maneuvering of water transport, as well as monitoring indicators or operational parameters of ships during operation. Positioning accuracy is ensured both by a more accurate determination of the coordinates of the vessel, and by the fact that in the implementation of the invention the values ​​of the projections of its velocity vector are determined. In the system of high-precision local 3D positioning of water vehicles for navigation and maneuvering on dangerous sections of inland waterways, the complex of onboard equipment includes four on-board transmitting stations located at the bow, aft and on the right and left sides of the midships of the water vehicle hull, which emit radio signals at different frequencies and are synchronized by a common highly stable reference oscillator. The coastal equipment includes eight signal receiving stations located along the right and left banks of the channel at the vertices of a cube with a side equal to the width of the channel, and connected to a computing unit, which, in addition to the current coordinates of the water vehicle, determines the values ​​of the projections of its velocity vector.

EFFECT: improving the safety of navigable hydraulic structures on inland waterways by improving the accuracy of 3D positioning of water vehicles in navigable hydraulic structures.

2 cl, 2 dwg

Description

The invention relates to means for ensuring navigation and maneuvering of water transport, as well as monitoring indicators or operational parameters of vessels during operation.

In the operation of various vehicles, satellite systems for global positioning and navigation (GLONASS, GPS, Galileo, Compass) are currently widely used. At the same time, an appropriate receiving device and a monitor are installed on the vehicle, displaying its current position and additional navigation information, for example, patent RU 2394719 C2. The accuracy of vehicle positioning using global positioning and navigation satellite systems does not exceed 0.5 m and is usually a few meters (https://omnicomm.su/about/news/sistema-glonass-era-glonass-i-gps-kak- rabotaet-i-dlya-chego-nuzhna-/). However, for maneuvering water vehicles with large dimensions and weight, especially in dangerous sections of inland waterways, in canals, locks, when mooring, such accuracy is insufficient.

To improve the positioning accuracy of a moving water vehicle, the information of the satellite positioning system is supplemented with data from on-board measuring devices of the current parameters of the vehicle's movement: the track angle, the angular rate of turn in the horizontal plane, the speed vector of the forward motion, the thrust force of the propellers, for example, patents RU 2403169 C1, RU 2406645 C1.

To position a water vehicle in a vertical plane relative to the free water surface, water vehicle draft sensors are used, for example, RU 2151710 C1, RU 2284944 C2, RU 2668003 C1. However, this positioning method does not provide critical information for the safety of a water vehicle about the distance from the bottom point of the bottom of the vehicle to the top point of the obstacle at the bottom of the dangerous section of the fairway.

The next step towards improving the positioning accuracy of a moving water vehicle is the use of ground navigation aids - leading beacons, optical, laser or microwave, in combination with on-board receivers that allow calculating the coordinates of a moving water vehicle relative to these beacons, for example, RU 2263329 C1, RU 2411159 C1, RU 2491204 C1, US 2007236389 A1. Compared to global navigation satellite systems, such systems allow to increase the positioning accuracy by two orders of magnitude due to the fact that the distance from the vehicle to the ground beacon is three orders of magnitude less than to the navigation satellite. However, the listed technical solutions do not imply 3D positioning of water vehicles, because do not require the mandatory placement of several beacons at different heights relative to the water vehicle. If all the beacons and the water vehicle are placed in the same plane, it is impossible to determine the coordinates along the axis orthogonal to this plane.

A comprehensive solution for ensuring trouble-free movement of a surface or underwater vessel in the presence of underwater or surface potentially dangerous objects due to the high-precision positioning of these dangerous objects relative to the vessel is described in patent RU 2513198 C2. A method is described for ensuring accident-free movement of a surface or underwater vessel in the presence of underwater and surface potentially dangerous objects, which includes the constant reception of satellite navigation data, data from a radar station, an automatic identification system, determining the position of the vessel, calculating the speed of the vessel, depth under the keel. Additionally, they include operations according to which a three-dimensional image of the underwater situation is obtained from all sides of the vessel, in front, from the sides and behind, for which sonar is used in the front, rear, left and right areas, if potentially dangerous objects are detected, they are recognized either by the navigator himself, or recognizing device and choose the best way to prevent the ship from colliding with a potentially dangerous object, and calculate the trajectory of avoidance from a potentially dangerous object. Thus, the probability of accident-free movement of a surface and underwater vessel in various potentially dangerous emergency situations increases. A feature of this technical solution is the concentration of all navigation and measurement tools on board the ship, which ensures maximum autonomy of navigation and independence from the availability of coastal infrastructure.

In the conditions of navigation on inland waterways, an alternative approach can be useful: a minimum set of navigation equipment is placed on water vehicles, and the main parts of the high-precision 3D positioning system are concentrated in dangerous sections of waterways, primarily in navigable hydraulic structures. The expediency of such an approach is determined by the ratio of the number of river vessels and the safety of hydraulic structures subject to declaration. For example, in the Russian Federation, the number of river vessels exceeds 30,000 units (https://poisk-ru.ru/s7493t6.html), and the number of hydraulic structures subject to safety declaration is 332 (http://morflot.gov.ru/deyatelnost/napravleniya_deyatelnosti /rechnoy_flot/vvt/sudohodnyie_gidrotehnicheskie_soorujeniya.html). In addition, high-precision 3D positioning at the points of loading and unloading operations will make it possible to control important operational parameters of vessels: roll, trim, deflection (bend) of the ship's hull.

Patent US 5696514 A "System for measuring location and speed using atomic clocks in moving objects and receivers" was chosen as a prototype. According to claim 10 of the claims, “A device for determining the location of a moving object is declared, comprising: a transmitting means carried by this moving object for transmitting a coherent signal containing an accurate frequency; and receiving means comprising a plurality of spaced apart receiving stations, means for determining a propagation time for said transmitted signal to reach each of said receiving stations, means for determining a velocity component from a frequency difference of said transmitted coherent signal received at each receiving station, and said exact frequency, and processor means for determining said location by propagation time for said transmitted coherent signal to reach each station, and resolving any ambiguities at said location derived from said transmitted signal propagation time using said rate components."

The disadvantage of using the prototype as a system for high-precision local positioning of water vehicles for navigation and maneuvering in dangerous sections of inland waterways is the presence of a single transmitting station on board. This does not allow 3D positioning of a water vehicle as a rigid body of finite dimensions, which is fundamentally necessary for navigation and maneuvering in dangerous sections of inland waterways, primarily in navigable hydraulic structures.

The technological problem solved by the invention is the creation of a system for high-precision local 3D positioning of water vehicles for navigation and maneuvering in dangerous sections of inland waterways, primarily in navigable hydraulic structures, in which the main part of the equipment is located on the shore, and the onboard part of the equipment minimal.

EFFECT: improving the safety of navigable hydraulic structures on inland waterways by improving the accuracy of 3D positioning of water vehicles in navigable hydraulic structures.

The specified technical result is achieved by the fact that the system of high-precision local 3D positioning of water vehicles for navigation and maneuvering on dangerous sections of inland waterways, contains a complex of on-board equipment and a complex of coastal equipment interconnected by several navigation and communication radio links, moreover, a complex of on-board equipment includes an onboard transmitting station that emits continuous unmodulated or modulated microwave radio signals into the surrounding space, and the complex of coastal equipment includes a computing unit, to which are connected spaced apart stations for receiving signals and a unit for graphical display of navigation information, as part of the onboard equipment complex includes at least three onboard transmitting stations, which are synchronized by a common highly stable reference oscillation generator, separated from each other by the maximum possible distance and located wives not in one straight line, the airborne equipment complex additionally includes onboard terminal equipment of the “board-to-shore” radio link, the coastal equipment complex uses at least six signal receiving stations located not in the same plane, the following are additionally connected to the computing unit: automatic a water level gauge in a navigable hydraulic structure, a memory block containing an up-to-date database of digital 3D models of a water vehicle and a bottom topography of a navigable hydraulic structure, as well as onshore terminal equipment of the “board-to-shore” radio link connected via a radio link to the onboard terminal equipment of the radio link air-to-shore communications.

The receiving stations as part of the onshore equipment complex are made according to a superheterodyne scheme with a common local oscillator synchronized by a highly stable reference oscillation generator.

The invention is illustrated by illustrations, which show:

Fig. 1 - Structural diagram of a system of high-precision local 3D positioning of water vehicles;

Fig. 2 - A specific example of the system.

The structure of the high-precision local 3D positioning system for water vehicles is illustrated by the diagram shown in Fig. one.

The system contains a complex of onboard equipment and a complex of coastal equipment interconnected by several navigation and communication radio links.

Onboard equipment complex (K1) includes:

- at least three airborne transmitting stations (1), emitting continuous unmodulated or modulated microwave radio signals into the surrounding space. The radiation centers of the transmitting antennas of the three onboard transmitting stations, structurally rigidly connected to the hull of the watercraft and not located on the same straight line, are reference points on the hull of the watercraft, and the coordinates of these three reference points uniquely determine the position of the hull of the watercraft in three-dimensional space. Increasing the number of reference points to more than three gives redundant information about the position of the positioned object, which increases the positioning accuracy due to mutual compensation of errors in determining the coordinates of the reference points. Determining the coordinates of the radiation centers of transmitting antennas on a moving vehicle is possible by determining the projections of the full velocity vector onto directions to several, at least six, spaced apart in space and not located in the same plane, fixed signal reception stations. The measurement of at least six linearly independent projections of the velocity vector is necessary for the unambiguous resolution of the system of equations, which includes six independent unknown quantities: three coordinates of the reference point and three components of the full vector of its velocity. Measuring the projection of the velocity vector of the source of radio waves in the direction to the receiving point is to measure the Doppler frequency shift of the received wave relative to the transmitted one. To measure the difference between these two frequencies with the required accuracy, it is necessary to maintain the transmitter frequency with the required accuracy and measure the frequency of the received signal with the maximum possible accuracy. The maximum accuracy of maintaining the frequency of the transmitter is achieved when synchronized with the atomic frequency and time standard (http://www.gaoran.ru/russian/lg/at%26f.html). The maximum frequency estimation accuracy is achieved using a continuous unmodulated harmonic oscillation :~:text=1.2.4%20When measuring%20%20frequency deviations,the%20%20%20%20%20methodsof%20should be given%20by a%20measurement%20method - Appendix A, p.A.1.2, page 10). In order for the signals of three or more aircraft transmitting stations to be distinguished from each other when received, they must either have different frequencies or have a unique modulation structure, such as orthogonal codes.

- Highly stable reference oscillation generator (2) connected to onboard transmitting stations (1). Oscillations of the highly stable reference oscillation generator (2) are fed to the reference inputs of the phase locked loop system of the microwave generators of the onboard transmitting stations, setting the required high level of frequency stability of the emitted signals.

- On-board terminal equipment of the radio link "board-to-shore" (3), connected by radio link to the shore terminal equipment of the radio link "board-to-shore" (9) and intended, first of all, for receiving navigation information necessary for maneuvering a water vehicle transmitted from the coastal equipment complex (K2). In the aspect of the technical result achieved by the invention, navigation information is understood as the current position of the hull of a water vehicle in the navigable channel of a hydraulic structure and the forecast of this position for the time lag of making a decision.

The coastal equipment complex (K2) includes:

- a computing unit (4), connected by its inputs to the output of an automatic water level meter (5), to the outputs of signal receiving stations (6) of onboard transmitting stations and to the output of a memory unit (7) containing the current database of 3D models of a water vehicle and the bottom topography of the navigable hydraulic structure, as well as connected by its outputs to the input of the block (8) for graphic display of navigation information - the current position of the water vehicle hull in the navigable channel of the hydraulic structure and the forecast of this position for the time lag of the decision - and the input of the coastal terminal equipment of the radio link air-to-shore communications (9).

- Automatic water level meter (5) in a navigable hydraulic structure with electronic registration of measurement results and an absolute measurement error of the order of 1 cm, the output of the automatic water level meter is connected to the input of the computing unit (4).

- At least six signal receiving stations (6) onboard transmitting stations, the receiving antennas of the signal receiving stations are rigidly connected to the permanent structures of the navigable hydraulic structure, the coordinates of the antenna radiation centers are known and are not located in the same plane, the distances between all receiving antennas are, if possible, maximum within of a specific navigable hydraulic structure, the outputs of the stations for receiving signals from the onboard transmitting stations are connected to the inputs of the computing unit (4).

- A memory block (7) containing an up-to-date database of digital 3D models of a water vehicle and a bottom topography of a navigable hydraulic structure, connected by its output to the input of a computing unit (4).

- Block (8) for graphical display of navigation information - the current position of the hull of the water vehicle in the navigation channel of the hydraulic structure and the forecast of this position for the time lag of the decision, connected by its input to the output of the computing unit (4).

- Coastal terminal equipment of the radio link "board-to-shore" (9), connected by its input to the output of the computing unit (4) and connected via a radio link to the on-board terminal equipment of the radio link "board-to-shore" (3).

The operation of the system is illustrated by a specific example (Fig. 2). In figure 2, the designations are similar to those in figure 1. Additionally, a device (10) is introduced - a microwave generator synchronized by a highly stable reference oscillation generator as part of the onshore complex. Four onboard transmitting stations (1) are used as part of the onboard complex, they are located on the bow, on the stern and on the right and left sides of the amidships of the water vehicle hull. As part of the coastal complex, eight signal receiving stations (6) are used, located on the right and left banks of the channel at the tops of a cube with a side equal to the width of the channel. Continuous harmonic signals are used with frequenciesf _one,f ₂,f ₃ Andf ₄. The signal generators of all onboard transmitting stations (1) are synchronized by a highly stable reference oscillator (2) with a relative frequency instability of 10^-eleven. As part of the coast stations for receiving signals (6), superheterodyne-type receiving devices are used, in which the local oscillator signal with a frequencyf _LO is common to all receiving stations and is formed by a microwave generator synchronized by a highly stable reference oscillation generator as part of the coastal complex (10), with a relative frequency error of 10^-eleven.

The system works as follows.

The navigator of the water vehicle turns on the onboard transmitting stations (1) before entering the navigable hydraulic structure for a time sufficient for the generators of the onboard transmitting stations to enter the operating mode. By the time the water vehicle enters the navigable hydraulic structure, the onboard transmitting stations (1) operate in frequency stabilization mode with a relative instability of 10 ^-11 . Four signals simultaneously emitted by onboard transmitting stations (1) are received by eight signal receiving stations (6) of the coastal complex. In the intermediate frequency path of each of the eight receivers, sums of signals with intermediate frequencies f _if equal to ( f ₁ - f _LO ), ( f ₂ - f _LO ), ( f ₃ - f _LO ) and ( f ₄ - f _LO ) are formed , which are separated by appropriate bandpass filters and digitized with sampling frequency f ₀ ≥ 5 × f _if . Samples of N samples of digitized signals are transferred to the computing unit (4).

Samples with sample number n of the k -th transmitter signal ( k = 1, 2, 3 and 4) received by the l -th receiver ( l = 1,…, 8) at the reference time t _i , I = 1,…, N

where A _kl is the signal amplitude,

λ _k = c/f _k is the wavelength of the k -th transmitter, c is the speed of light,

r _kl is the distance from the antenna of the k -th transmitter to the antenna of the l -th receiver,

θ _k is the initial phase of oscillations of the k -th transmitter.

Signal spectrum is calculated

=FFT

,

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,

the spectrum of the analytical signal is calculated

,

,

analytical signal is calculated

,

,

the current phase of the analytical signal is calculated

.

.

The procedure is repeated with the sample number ( n + 1), the difference of the current phases is calculated with averaging over N samples

.

.

The phase increment of the signal of the k -th transmitter, received by the l -th receiver, is caused by a change in the distance between them - Δ r _kl during the time between the registration of samples with numbers n and n +1. Wherein

.

.

Based on the results of calculating the displacement of the k -th transmitter relative to
l -th receiver, a system of equations is compiled

where ( x _{k 0} , y _{k 0} , z _{k 0} ) are unknown coordinates of the k -th transmitter,

(Δ _{x k} , Δ _{y k} , Δ _{z k} ) are the components of the unknown displacement vector of the k -th transmitter,

( x _l , y _l , z _l ), l = 0,…, 8 – known coordinates of the l -th receiver,

Δ _kl is the measured length (with a sign) of the projection of the displacement vector onto the beam from the k -th transmitter to the receiver with the number l .

For each airborne transmitting station (1), a system of eight nonlinear equations with six unknowns (U.1) is obtained, which is solved by any iterative method, for example, Newton. As an initial approximation of the coordinates and speed of the onboard transmitting station (1) in the case of the first (at the beginning of the positioning procedure) measurement, one should take some a priori or external data, for example, from a radar or GLONASS data from a water vehicle. Due to the low accuracy of estimating the initial coordinates and speed of the water vehicle, the first iterative procedure may take a little longer.

After resolving the system of equations for the first measurement, the initial coordinates of the target ( x _{k 0} +Δ _{x k} , y _{k 0} +Δ _{y k} , z _{k 0} +Δ _{z k} ) and the displacement vector are used as the initial approximation of the iterative procedure for the second and subsequent measurements (Δ _{x k} , Δ _{y k} , Δ _{z k} ) according to the previous measurement. The proximity of the initial approximation to the true values of the unknown quantities will reduce the number of required iterations to one or two. Also, after resolving the system (U.1), during the first measurement in subsequent measurements, you can substitute into the system (U.1) instead of unknown variables ( x _{k 0} , y _{k 0} , z _{k 0} ) known estimates of the quantity ( x _{k 0} +Δ _xk , y _{k 0} +Δ _yk , z _{k 0} +Δ _zk ), found during the previous measurement. After that, the system (U.1) becomes linear with respect to three unknowns (Δ _{x k} , Δ _{y k} , Δ _{z k} ). Of the eight equations, only three can be left. They should be chosen according to the maximum values of the coefficients ( x _l - x _{k 0} ), ( y _l - y _{k 0} ), ( z _l - z _{k 0} ). After that, it remains only to solve the system of three linear equations in three unknowns (Δ _xk , Δ _yk , Δ _zk ). The new target coordinates are defined as ( x _{k 0} +Δ _xk , y _{k 0} +Δ _yk , z _{k 0} +Δ _zk ).

With a large signal-to-noise ratio in the receiver, the error in estimating the displacement vector of the onboard transmitting station is determined by the relative frequency instability δ f _k

where F _k = V _k /λ _k is the Doppler frequency shift at wavelength λ _k at transmitter speed V _k . With a signal frequency of 950-960 MHz, a relative frequency instability of 10 ^-11 and a speed of 1 cm / s, the error will be ± 1.6 cm. If the signal frequency is tripled, the displacement estimation error will decrease by an order of magnitude.

The estimates of the coordinates of the radiation centers of the antennas of the onboard transmitting stations (1) obtained in this way are used as reference points of the digital 3D model of the water vehicle loaded into the computing unit (4) from the memory unit (7) together with the 3D model of the navigable hydraulic structure displayed on the a block for graphical display of navigation information (8) of the coastal complex of the system and transmitted over the radio link through the coastal terminal equipment of the radio link “board-to-shore” (9) to the on-board terminal equipment of the radio link “board-to-shore” (3). The current value of the water level in the reservoir of a navigable hydraulic structure is determined from the readings of an automatic water level meter (5) with known coordinates of its installation site with an error of about 1 cm and is used in the 3D model of a navigable hydraulic structure as a parameter.

Obtained in addition to the current coordinates of the water vehicle, the values of the projections of its speed vector (the displacement vector for the time between the registration of samples with numbers n and n + 1) make it possible to predict the subsequent movements of the water vehicle and, thus, to predict the occurrence of emergency situations in the navigable hydraulic structure .

The industrial implementation of the proposed system is possible on the basis of commercially available communication equipment, measuring instruments and computer equipment known from the general level of technology. In particular, the following are known: WO 2018109435 A1 - A projectile control system using a plurality of transmitters and receivers of electromagnetic waves and determining the coordinates and speed of the control object; US 5870056 A - Passive air-to-air positioning system that determines the coordinates and velocity of an active target by measuring both Doppler frequency shift and phase shifts in a long baseline interferometer.

Critical to the industrial implementation of the system are measuring ^devices that provide a positioning accuracy of about 1 cm. oscillations, rubidium frequency and time standards Ch1-1020/2 with a systematic relative change in the frequency of the output signal of 10 (5) MHz for 1 day, no more than ± 2 × 10 ^-12 , produced by NPP OOO GNOMON, Russia, can be used (https: //rubikom.org/catalog/rubidievyie-opornyie-generatoryi-i-standardtyi-chastotyi/standart-chastotyi-i-vremeni-rubidievyij-ch1-1020-2.html). Devices Ch1-1020/2 can be produced in the version for use on vehicles. Submersible level gauges ALZ 3720 k from Piezus LLC, Russia, for use in water transport, with an error of not more than 0.2% of the measurement range (https://piezus.ru/ media/catalog/product/alz3720_kru.pdf).

Thus, the proposed invention improves the safety of navigable hydraulic structures on inland waterways by improving the accuracy of 3D positioning of water vehicles in navigable hydraulic structures.

Claims (2)

1. System for high-precision local 3D positioning of water vehicles for navigation and maneuvering on dangerous sections of inland waterways, containing an onboard equipment complex and a coastal equipment complex interconnected by several navigation and communication radio links, and the onboard equipment complex includes an onboard transmitting station , emitting continuous unmodulated or modulated radio signals of microwave frequencies into the surrounding space, and the complex of coastal equipment includes a computing unit, to which are connected spaced apart stations for receiving signals and a unit for graphical display of navigation information, characterized in that the complex of onboard equipment includes four on-board transmitting stations located at the bow, stern and on the starboard and port sides of the midsection of the hull of a water vehicle, which emit radio signals at different frequencies and are synchronized by a common a highly stable reference oscillation generator, the onboard equipment complex additionally includes onboard terminal equipment of the “board-to-shore” radio link, the onshore equipment complex includes eight signal receiving stations located along the right and left banks of the channel at the tops of a cube with a side equal to the width of the channel , and connected to the computing unit, which in addition to the current coordinates of the water vehicle determines the values of the projections of its velocity vector, additionally connected: an automatic water level gauge in the navigable hydraulic structure, a memory unit containing an up-to-date database of digital 3D models of the water vehicle and relief the bottom of a navigable hydraulic structure, as well as the coastal terminal equipment of the “board-to-shore” radio link, connected via a radio link to the on-board terminal equipment of the “board-to-shore” radio link. 2. The system according to claim 1, characterized in that the receiving stations as part of the onshore equipment complex are made according to a superheterodyne circuit with a common local oscillator synchronized by a highly stable reference oscillation generator.

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