RU2488842C1 - More precise positioning in underwater navigation space formed by randomly arranged hydroacoustic transponder beacons - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: result is achieved by integrating inertial, hydroacoustic, hydrostatic and magnetic measurements via digital statistical optimum processing of an excess number of measurements of parameters of movement and positioning of the object to estimate instrument errors, consistence of which is based on equally accurate hydroacoustic measurements for determining global coordinates of hydroacoustic transponder beacons as the positioning object moves from the point of inputting initial values of global coordinates and then determining more precise spatial global coordinates of the positioning object and orientation angles thereof.

EFFECT: high accuracy of positioning on coordinates and orientation angles.

2 cl, 1 dwg, 1 tbl

Description

The invention relates to underwater navigation and can be used for underwater technical work for general and special purposes using autonomous uninhabited underwater vehicles (AUVs) with automatic or supervisory control, autonomously performing operations that require updated positioning of AUVs.

To increase the accuracy of positioning of underwater objects, technical solutions based on the use of an excessive number of trajectory definitions by various navigation aids are known. These are hydroacoustic navigation systems with long bases (HANS-DB) and ultrashort (HANS-UKB), inertial navigation systems (ANNs) with stabilized platforms and satellite-based GPS global positioning system. In the case of underwater positioning of the AUV, satellite navigation is used in the mode of periodical corrections of coordinates during the ascent of the AUV or in the mode of regular adjustments during the operation of the AUV with a supply vessel (OS) and the presence of sonar communication between them.

The most complete representation of these solutions is given in the monograph "Autonomous underwater work: systems and technologies", authors M.D. Ageeva L.V. Kiselev, Yu.V. Matvienko et al., Edited by M.D. Ageeva, Institute of Marine Technology Problems. M .: Nauka, 2005.

In this work, in the navigation complex of the IPMT FEB RAS (pp. 157-160), the positioning of the AUV is solved by combining GANS-DB and GANS-UKB using beacon transponders and with the participation of the GPS shipboard navigation complex OS. At the same time, the network of responder beacons with the determination of their coordinates is prepared previously and again with the participation of the GPS navigation complex of the OS, and to ensure acceptable accuracy of observation, the network of responder beacons is subjected to periodic auto-calibration (p. 117-118). In this case, the GANS-UKB system integrated with GANS-DB with a range of 6-10 km gives a relative error of 10 ^-2 (p. 157).

The considerable laboriousness of this AUV positioning technology with its low accuracy is expensive and it cannot be used for a large amount of work related to the technical and environmental monitoring of oil and gas pipelines on the seabed.

Known technical solutions (see "The method of determining the horizontal coordinates of a stationary underwater source of hydroacoustic navigation signals", patent of the Russian Federation No. 2378663; and "The method of determining bearing on a radiation source and device for its implementation" Patent of the Russian Federation No. 2158430), which are aimed only at providing preliminary positioning of responder beacons for subsequent navigational determinations of the AUV on the GANS-DB and GANS-UKB systems with the participation of the GPS navigation complex OS.

The GAPS (Global Acoustic Positioning System) system of iXsea, France (see the GAPSru 0509 corporate catalog, 2005 or the Internet resource http: www.ixsea.com) was selected as a prototype of the invention.

In this technical solution, to improve the accuracy of positioning of underwater objects, a fusion of sonar and inertial technologies using GPS through a supporting vessel is implemented.

At the same time, for inertial navigation definitions, an inertial navigation system (ANS) with a stabilized platform of up to several tens of cubic decimeters is used, and for sonar coordinates, a HANS-UKB with a range finder and direction finder with two mutually perpendicular ultrashort bases is used to determine bearing angles and heights, and defendant beacons are installed in the waters with the definition of their global geographical coordinates.

In the prototype, the merger of inertial and hydroacoustic technologies for positioning an autonomous underwater object using GPS data occurs through the evaluation of the arithmetic mean between the coordinates of the object and its orientation angles obtained simultaneously in different navigation systems. The positioning accuracy in the prototype is estimated at coordinates of 0.2% at a range of up to 4000 m (this is plus minus 8 m) and at angles plus minus 0.12 degrees.

The basis of the invention is the task to develop such a method of refined positioning in an underwater navigation space formed by arbitrarily placed sonar beacons-transponders and a system for its implementation, which will improve the accuracy of positioning in coordinates and orientation angles.

This will reduce costs during underwater technical work in the navigation space formed by transponder beacons arbitrarily installed in the water area (installation from an underwater position is allowed) without first determining their coordinates.

The problem is achieved in that in the method of refined positioning in the underwater navigation space formed by randomly placed sonar beacons-transponders, which consists in obtaining data from an inertial navigation system, sonar navigation system, as well as a satellite-based global positioning system, according to the invention, sonar beacons-responders are arranged according to the invention water areas arbitrarily without prior determination of their global coordinates, enter the beginning According to the definitions of the satellite system of global positioning, the global global coordinates in the positioning object only once before the start of its immersion, hold the positioning object for 10-30 seconds in the submerged state before the start of movement, measure the heading angles, heel, trim with a digital magnetometric compass, the depth of the object positioning by a hydrostatic pressure sensor and determine the global coordinates of the positioning object by measurements with a discrete of 100 Hz micromechanical with sensors of a strapdown inertial navigation system, they then send hydroacoustic requests encoded by a serial number from the positioning object to the responder beacon, decode the request signal at the responder beacon, measure the installation depth of the responder beacon and simultaneously encode the response beacon number and send from the beacon response to the positioning object, where the received response is decoded, the speed of sound is measured, the slant range to the responder beacon is determined, the bearing angle to it, and the difference the bin of the positioning object and the responder beacon, then determine the global coordinates of the responder beacons that fell into the area of hydroacoustic interaction with the positioning object at the time of entering the initial global coordinates from the satellite global positioning system and holding the positioning object in the submerged state, determine the global coordinates of the positioning object by measurements sonar navigation system with ultrashort base, determine the assessment of instrumental error sensors By combining inertial, hydroacoustic, hydrostatic and magnetic redundant measurements, the specified global coordinates of the positioning object are determined taking into account the estimates of instrumental errors, and when the positioning object is moving, the global coordinates of the transponder beacons for the first time falling into the region of hydroacoustic interaction with the positioning object are determined using the value global coordinates of the positioning object at the moment of the first contact with the responder beacon.

The problem is also solved by the fact that the system of refined positioning in the underwater navigation space formed by arbitrarily spaced sonar beacons-transponders, containing the positioning object and sonar beacon-responder, differs in that an additional counter of hydroacoustic signals is introduced into the positioning object, the output of which is connected to the input of the coding and decoding unit, and the output of the latter is connected to the receiving-emitting device of the positioning device to the inclined range meter and the defendant beacon and bearing on it and to the input of the unit for determining the coordinates of the beacon-responder, the output of which, together with the output of the unit for measuring the speed of sound, are connected to the unit for calculating the coordinates of the hydroacoustic navigation system with an ultrashort base, and also in addition to the positioning object a unit for integrating inertial, hydroacoustic, magnetic and hydrostatic measurements with an error estimation of their sensors has been introduced, the inputs of which are connected to the output of the coordinate determination unit inat and orientation angles of the strapdown inertial navigation system and with the output of the unit for determining the coordinates of the hydroacoustic navigation system with an ultra-short base, with the output of a digital magnetometric compass with the measurement of orientation angles, with the output of the depth sensor of the positioning object, and the output is connected to the input of the unit for determining the specified global coordinates and angles orientation of the positioning object, and in the beacon-transponder, an additional unit for decoding the number of the hydroacoustic request, the input of the cat It is connected to the output of the receiver-emitting device of the responder beacon, and the output is connected to the input of the coding block of the request number, number of the responder beacon and depth of the responder beacon; in addition, the depth sensor, the indicator unit of the responder beacon number are additionally introduced into the beacon which are connected to the inputs of the coding block of the request number, the number of the responder beacon and the depth of the responder beacon, and the output of the latter is connected to the input of the receiver-emitting device of the responder beacon.

The technical result is achieved by combining inertial, hydroacoustic, hydrostatic and magnetic measurements using digitally statistically optimal processing of an excessive number of measurements of movement parameters and positioning of an object to evaluate instrumental errors, the consistency of which is based on equal-accurate hydroacoustic measurements to determine the global coordinates of sonar beacons responders in the process of moving an object positioning from the point of introduction of the initial values values of global coordinates and after that, the specified spatial global coordinates of the positioning object and its orientation angles are determined.

The block diagram of the system for refined positioning in the underwater navigation space formed by arbitrarily placed sonar beacons-transponders is shown in the figure, where the following notation is adopted:

1 - A block of initial global coordinates for the GPS receiver.

2 - Block micromechanical sensors inertial measurements SINS.

3 - Block determining the coordinates and orientation angles SINS.

4 - Block determining coordinates GANS-UKB.

5 - Block encoding and decoding.

6 - Counter request hydroacoustic signals.

7 - The receiving-emitting device of the positioning object and the slant range meter to the responder beacon and the bearing on it.

8 - Receiving device of the transponder beacon.

9 - Block decoding the number of sonar request.

10 - Coding block of the request number, the number of the responder beacon and the depth of the responder beacon.

11 - Depth sensor of the responder beacon.

12 - Block marker number of the respondent beacon.

13 - Block for measuring the speed of sound.

14 - Digital magnetometric compass for measuring orientation angles.

15 - Depth sensor of the positioning object.

16 - Block integration measurements and error estimation sensors.

17 - Block for determining refined global coordinates and orientation angles of the positioning object.

18 - Block determining the coordinates of the beacon-responder.

19, 20 - Autonomous power sources of the positioning object and transponder beacons.

21 - Hardware module positioning object.

22 - Hardware modules of transponder beacons.

23 - Hydroacoustic navigation system with ultrashort base (HANS-UKB).

24 - Strap-on inertial navigation system (SINS).

To solve this problem, the positioning object is equipped with a hardware module (pos. 21) composed of a strapdown inertial navigation system (pos. 24) with micromechanical sensors and a volume of about 0.8 dm ³ , and sonar transponders are equipped with hardware modules (pos. 22 )

According to the invention, for precise positioning of an underwater object in a certain water area, an underwater navigation space is preliminarily formed by arbitrary arrangement of responder beacons to the depths determined by the lengths of the buoyrps and the depth of the installation site. Before dumping the beacon-responders include its standby channel with energy-saving consumption.

Before launching, the global satellite coordinates of the launch and holding positioning object in the submerged quiescent position for initial adjustment of the measuring sensors for 10 ÷ 30 s to obtain the number of sonar exchanges with beacons are introduced into the positioning object from the initial global coordinate unit via the GPS receiver (item 1) -responders providing statistical sufficiency and adaptation of the object with a prepared navigation space.

During this period, both BINS navigation systems (pos.24) and GANS-UKB (pos.23) operate and the global coordinates of the responder beacons located in the zone of interaction with the positioning object are determined.

The coordinates and angles of orientation of the positioning object are determined in the unit for determining the coordinates and orientation angles of the SINS (pos. 3), according to the results of measurements with a 100 Hz discrete in the block of micromechanical sensors of inertial measurements (pos. 2) from the beginning to the end of the mission of the positioning object, continuously at the pace of the set discrete, and this data enters the unit for integrating measurements and evaluating sensor errors (pos. 16).

The determination of the coordinates of the positioning object in the HANS-UKB (pos. 23) is not regular and depends on the distance of the moving positioning object to the transponder beacon. At the same time, the hydroacoustic interrogation signal is generated continuously with a given discrete in the coordinate determination unit in the HANS-UKB (item 4), is encoded by a serial number in the encoding and decoding unit (item 5), and enters the receiving-emitting device of the positioning object and the slant range meter to the beacon - a responder and a bearing on it (pos. 7) for radiation into the aquatic environment. As soon as the positioning object enters the zone of hydroacoustic interaction with the transponder beacon, its standby mode goes into working mode and hydroacoustic information exchange begins to form. The hydroacoustic interrogation signal through the receiver-emitting device of the responder beacon (pos. 8) enters the unit for decoding the hydroacoustic request number (pos. 9) to decode the request number and then to the encoding unit of the request number, the number of the responder beacon and the depth of the responder beacon (pos. 10) for joint coding of the values of the measured depth of the beacon-responder with the sensor for measuring the depth of the beacon-responder (pos. 11), the number of the beacon-responder from the block of the marker of the number of the beacon-responder (pos. 12) and subsequent transmission to the receiving-emitting device The property of the responder beacon (pos. 8) for sending a hydroacoustic response to the positioning object. After receiving the positioning object and the slant range meter to the transponder beacon and the bearing to it (pos. 7) in the receiving-emitting device, the hydroacoustic response is decoded in the encoding and decoding unit (pos. 5) and arrives at two addresses: the unit for determining the coordinates of the beacon - the defendant (pos. 18) using the values of the orientation angles coming from the unit for determining the adjusted global coordinates and the orientation angles of the positioning object (pos. 17); the second address is the GANS-UKB coordinate calculation unit (pos. 4), which, in addition to the data of the pos. 5 block, receives the updated values of the orientation angles from the pos. 17 block, the measured sound velocity from the pos. 13 block, and the coordinates of the responder beacon from block pos. 18.

To ensure noise immunity of the information exchange via the hydroacoustic channel, phase-shift coding / decoding is used in the block (item 5) in the positioning object and in the blocks (item 9 and 10) of the transponder beacon.

The results of the trajectory definitions for the two navigation systems of the blocks (items 3 and 4) come with the measurements of the heading, roll and trim angles with a digital magnetometric compass (item 14), a depth sensor for the positioning object (item 15) and a depth sensor for the transponder beacon ( Pos. 11) enter the unit for aggregation and error estimation of measurement sensors (pos. 16) for statistically optimal processing of an excess number of measurements by sensors of various physical nature, combining the processing on a complete sample with processing on a recurrence scheme. The resulting evaluation of instrumental errors of the sensors minimizing residuals in the trajectory definitions are used to determine refined global coordinates and orientation angles of the positioning object in the block (item 17).

The possibilities of refined underwater positioning of a positioning object according to the invention can be demonstrated on the results of digital modeling when processing a simulator of full-scale measurements, the formation of which is carried out on a digital model of an “ideal” picture of the movement of a positioning object by introducing random errors distributed according to the normal law into the values of ideal motion parameters with offset Δ and standard deviation σ.

In the process of numerical studies for the simulator of field measurements, error options were formed from the following ranges of values taken from the results of laboratory bench tests of the hardware modules of the positioning object (item 21) and the transponder beacon (item 22) with full-scale sensors:

$$\Delta x_g^{(u)}=\Delta y_g^{(u)}=\Delta z_g^{(u)}=\pm (2÷10)m\text{- coordinates}$$

Δγ = 1 deg (roll) $$\Delta a_{x,y,z}^{(u)}=\pm (0.2÷\mathrm{one})m/{\mathrm{from}}^2\text{- linear accelerations}$$

Δψ = 0.4 deg (course) $$\Delta {\omega }_{x,y,z}^{(u)}=\pm (0.5÷\mathrm{1,5})gR\mathrm{but}d/\mathrm{from}\text{- angular velocities}$$

Δθ = 0.2 deg (trim) $${\text{σ}}_{{\text{ω}}_{\text{y}}{\text{, ω}}_{\text{y}}\text{, ω}}^{\text{(u)}}{}_{\text{z}}=(0.01÷0.04)gR\mathrm{but}d/\mathrm{from}$$

σ _γ = 0.06 deg $${\sigma }_{x_g}^{(u)}={\sigma }_y{}_y={\sigma }_z{}_y=(0.17÷\mathrm{1,0})m$$

σ _ψ = 0.04 deg $${\sigma }_{a_x,a_y,a_z}^{(u)}=(0.02÷0.04)m/{\mathrm{from}}^2$$

σ _θ = 0.02 deg

The table shows a comparison of the measurement error values entered in the simulator and the values of the obtained estimates during processing according to the integration program, which implies that the measurement measurement errors are estimated at the level of 95-98%, and taking them into account when determining orientation angles gives a deviation from the “ideal” values simulator in positioning coordinates in the range of plus or minus 0.325 meters, and in orientation angles in the range of plus or minus 0.1 degrees. The level of accuracy of positioning of the positioning object is preserved throughout the entire underwater navigation space, limited by the grouping of responder beacons, i.e. does not depend on the path traveled by the object in this space and the positioning range.

The technical result of the claimed invention is to reduce the error in determining the positioning coordinates and orientation angles of the positioning object in the space formed by arbitrarily placed sonar beacons-transponders while reducing the complexity and time costs.

Table. The results of the refinement of positioning according to the invention. Error simulation value / error rating Simulation Measurement Error Options Accuracy of coordinates and orientation angles taking into account error estimates for option 3 one 2 3 four 5 6

$$$$

$$\Delta a_x^{(u)}/\Delta {\widehat{a}}_x$$

1.0 / 0.968 2.0 / 1.08 2.0 / 1.77 1.0 / 1.043 1.0 / 0.97 $$\Delta a_y^{(u)}/\Delta {\widehat{a}}_y$$

0.2 / 0.195 -0.4 / -0.406 -0.4 / -0.397 0.2 / 0.087 0.2 / 0.199 $$\Delta a_z^{(u)}/\Delta {\widehat{a}}_z$$

0.2 / 0.217 0.4 / 0.482 0.4 / 0.399 0.2 / 0.0005 0.2 / 0.202 $$\Delta x_g^{(u)}/\Delta {\widehat{x}}_g$$

5 / 5,163 -10 / -9.65 4 / 4.12 5 / 5.12 5 / 5,2 δ _xg = ± 0.325 $$\Delta y_g^{(u)}/\Delta {\widehat{y}}_g$$

2 / 1.92 4 / 3.84 -10 / -10.3 2 / 1.89 2 / 2.16 δ _yg = ifl, 065 $$\Delta z_g^{(u)}/\Delta {\widehat{z}}_g$$

2 / 2.2 4 / 3.6 -4 / -3.71 2 / 2,13 2 / 1.83 δ _zg = ± 0.135 $$\Delta {\gamma }^{(u)}/\Delta \widehat{\gamma }$$

1 / 0.99 1 / 0.97 1 / 0.98 1 / 0.975 1 / 0.98 δ _γ = ± 0.08 $$\Delta {\psi }^{(u)}/\Delta \widehat{\psi }$$

0.4 / 0.395 0.4 / 0.38 0.4 / 0.38 0.4 / 0.38 0.4 / 0.38 δ _ψ = ± 0.1 $$\Delta {\theta }^{(u)}/\Delta \widehat{\theta }$$

0.2 / 0.198 0.2 / 0.197 0.2 / 0.19 0.2 / 0.198 0.2 / 0.198 δ _θ = ± 0.09

Claims (2)

1. The method of refined positioning in an underwater navigation space formed by arbitrarily placed sonar beacons-transponders, which consists in obtaining data from an inertial navigation system, sonar navigation system, and a satellite-based global positioning system, characterized in that sonar beacons-transponders are positioned arbitrarily without water preliminary determination of their global coordinates, enter the initial global coordinates in the position object according to the definitions of a satellite-based global positioning system, only once before the start of its immersion, hold the positioning object for 10-30 seconds immersed before the start of movement, measure the heading, heel, trim angles with a digital magnetometric compass, the immersion depth of the positioning object with a hydrostatic pressure sensor and determine the global coordinates of the positioning object from measurements with a 100 Hz discrete micromechanical sensors inertial strapdown on of the navigation system, then they send hydroacoustic requests encoded by a serial number from the positioning object to the responder beacon, decode the request signal on the responder beacon, measure the installation depth of the responder beacon and simultaneously encode the response beacon number and send from the responder beacon to the object positioning, where the received response is decoded, the speed of sound is measured, the slant range to the responder beacon is determined, the bearing angle to it and the depth difference of the positioning object and the responder beacon, then determine the global coordinates of the responder beacons that fell into the area of hydroacoustic interaction with the positioning object at the time of entering the initial global coordinates from the satellite global positioning system and hold the positioning object in the submerged state, determine the global coordinates of the positioning object from the measurements of the hydroacoustic navigation system with an ultrashort base, determine assessment of instrumental errors of sensors by combining inertial, hydro of bushy, hydrostatic and magnetic redundant measurements, determine the adjusted global coordinates of the positioning object taking into account the estimates of instrumental errors, and when moving the positioning object, determine the global coordinates of responder beacons that fall into the region of hydroacoustic interaction with the positioning object for the first time, using the value of the global coordinates of the positioning object at the moment of the first contact with the respondent beacon. 2. A system for refined positioning in an underwater navigation space formed by arbitrarily placed sonar beacons-transponders, comprising a positioning object and a sonar beacon-transponder, characterized in that the positioning object additionally has a counter of requested hydroacoustic signals, the output of which is connected to the input of the encoding and decoding unit , and the output of the latter is connected to the receiving-emitting device of the positioning object and the slant range meter about the responder beacon and bearing on it and to the input of the unit for determining the coordinates of the beacon-responder, the output of which, together with the output of the unit of the sound velocity meter, are connected to the unit for calculating the coordinates of the hydroacoustic navigation system with an ultrashort base, and an inertial complexing unit is also added to the positioning object, hydroacoustic, magnetic and hydrostatic measurements with error estimation of their sensors, the inputs of which are connected to the output of the unit for determining coordinates and orientation angles th inertial navigation system and with the output of the unit for determining the coordinates of the sonar navigation system with an ultrashort base, with the output of a digital magnetometric compass with measurement of orientation angles, with the output of the depth sensor of the positioning object, and the output is connected to the input of the unit for determining the adjusted global coordinates and orientation angles of the positioning object, and in the beacon-transponder, an additional unit for decoding the number of the hydroacoustic request, the input of which is connected to the output of the transceiver, is additionally introduced of the device of the responder beacon, and the output is connected to the input of the coding block of the request number, the number of the responder beacon and the depth of the responder beacon, in addition, the depth sensor, the indicator unit of the responder beacon number are additionally introduced into the beacon, the outputs of which are connected to the inputs the encoding unit of the request number, the number of the responder beacon and the depth of the responder beacon, and the output of the latter is connected to the input of the receiver-emitting device of the responder beacon.