A docking station and multi-sensor positioning system for deep-sea vertical vehicles

Abstract

This invention discloses a docking station and a multi-sensor information positioning system for deep-sea vertical navigation vehicles. The docking station utilizes four short-baseline transducer elements to construct an array. Using the array coordinate system, the first coordinate of the deep-sea vertical navigation vehicle in the array coordinate system is obtained by receiving the depth information of the vehicle and the docking station, and the incident angle of the deep-sea vertical navigation vehicle relative to the underwater acoustic array. Based on the docking station's own pose, the first coordinate is converted into the relative coordinate of the deep-sea vertical navigation vehicle in the geodetic coordinate system with the docking station as a reference, thereby achieving precise navigation. Furthermore, this invention achieves precise navigation using only one base station, avoiding positioning errors caused by deployment mistakes compared to existing technologies that require multiple base stations. It also eliminates the need for a mother ship carrying an SBL (Supersonic Boundary System) for surface-based positioning assistance, enabling the vehicle to autonomously travel between the surface and seabed for extended periods, performing long-term localized navigation missions.

Description

Technical Field

[0001] This invention belongs to the field of marine technology engineering, specifically relating to a docking station and multi-sensor information positioning system for deep-sea vertical vehicles. Background Technology

[0002] Autonomous underwater vehicles (AUVs) are a new type of mobile marine environmental observation equipment. They possess autonomous power and navigation systems and can be equipped with various sensors to conduct dynamic and three-dimensional observations of the marine environment. In recent years, researchers have been using underwater docking stations and underwater profilers to form docking systems for ocean observation. Once the AUV successfully docks at the docking station, the station provides energy resupply and information exchange to the AUV.

[0003] Compared to horizontally propelled vehicles, vertically propelled vehicles are more suitable for performing localized navigation missions between surface and seabed docking stations. They can reduce energy consumption through buoyancy adjustment, overcome drift caused by ocean currents, and increase docking success rate.

[0004] Patent application CN110884632A discloses a docking system for a hybrid vertical profiler, belonging to the field of marine engineering. It includes a docking base station fixed to the seabed and connected to a seabed observation network. The base station is equipped with: a guidance mechanism located at the top for guiding the hybrid vertical profiler during vertical docking; a limiting mechanism adapted to the head of the hybrid vertical profiler, including a triggering mechanism for triggering a locking mechanism and a wireless power / signal transmitting unit; and a locking mechanism for locking the hybrid vertical profiler. The hybrid vertical profiler is equipped with a wireless power / signal receiving unit for docking with the wireless power / signal transmitting unit to complete charging and signal transmission. The docking base station is fixed to the seabed and docks the hybrid vertical profiler vertically during its reciprocating profiling motion. After successful docking, the docking station supplies the vertical profiler with underwater wireless power and wireless data transmission.

[0005] Patent application CN119018318A discloses a cubic docking station for a deep-sea vertical profiler, specifically relating to the field of marine technology engineering. The cubic docking station includes a fixed frame, a clamping module, a limiting and throwing assembly, and a docking guidance mechanism. The fixed frame is also equipped with multiple buoyancy adjustment modules, which are stacked and fixed to the top side of the fixed frame. The buoyancy adjustment modules work together to rise and sink, facilitating the cyclical operation of the docking station. Furthermore, since the limiting and throwing assembly throws the counterweight and the buoyancy adjustment modules autonomously rise while simultaneously performing vertical docking and recovery of the vertical profiler underwater, the system is unaffected by ocean currents, resulting in a higher success rate and lower energy consumption.

[0006] However, the docking process between the aforementioned patent application-disclosed docking station and the AUV requires the use of underwater acoustic positioning combined with other multi-sensor methods for location. Current underwater acoustic positioning technology requires the pre-deployment of multiple base stations or the mother ship to follow the AUV's movement. Deploying multiple base stations on the seabed presents significant technical challenges, as it is difficult to maintain the correct placement of the base stations. Positional errors can cause ranging errors, increasing the risk of positioning mistakes. Furthermore, for missions involving long-term autonomous localized navigation, the mother ship cannot remain stationary in the sea area for extended periods, limiting its operational capabilities. Summary of the Invention

[0007] The docking station provided by this invention for deep-sea vertical vehicles can achieve relatively accurate positioning of the vehicle using only one base station, reducing positioning errors caused by multiple base stations and improving positioning accuracy.

[0008] This invention provides a docking station for deep-sea vertical vehicles, comprising:

[0009] The underwater acoustic transducer includes four short-baseline transducer elements arranged in a square to form an array. The short-baseline transducer elements are used to receive underwater acoustic signals from the deep-sea vertical vehicle and to transmit the relative coordinates of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference point to the deep-sea vertical vehicle.

[0010] The underwater acoustic electronic cabin is connected to the short baseline transducer element and is used to supply power to the underwater acoustic transducer and send commands. It is used to obtain the depth information of the deep-sea vertical vehicle from the underwater acoustic signal and to calculate the incident angle of the deep-sea vertical vehicle to the base station based on the time difference of receiving underwater acoustic data by different short baseline transducer elements.

[0011] The docking compartment of the vehicle is connected to the electronic control compartment and is equipped with a wireless charging coil for docking with the deep-sea vertical vehicle and transmitting electrical energy and high-frequency electromagnetic wave signals to the deep-sea vertical vehicle.

[0012] The electronic control cabin, connected to the underwater acoustic transducer, the underwater acoustic electronics cabin, and the vehicle docking cabin, is used to supply power to the underwater acoustic electronics cabin and the vehicle docking cabin. It is also used to obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the deep-sea vertical vehicle in the array coordinate system. Based on the docking station's own pose, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference. The relative coordinate is then sent to any one of the four short baseline transducer elements.

[0013] Preferably, the first coordinates of the vertical vehicle in the base station coordinate system are obtained based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, including:

[0014] The diagonals formed by connecting every two short baseline transducer elements at the four vertices of the square are used as the X-axis and Y-axis, respectively, and the intersection of the two diagonals is used as the origin of the matrix coordinate system.

[0015] The angle between the acoustic ray emitted by the vertically oriented vehicle and the X-axis is obtained based on the distance between the two short-baseline transducer elements on the X-axis and the time difference between the underwater acoustic signals received from the deep-sea vertical vehicle. ;

[0016] The angle between the acoustic ray emitted by the vertically oriented vehicle and the Y-axis is obtained based on the distance between the two short-baseline transducer elements on the Y-axis and the time difference of the received underwater acoustic signal from the vertically oriented vehicle. ;

[0017] Using the vertical distance between the deep-sea vertical vehicle and the docking station as the Z-axis coordinate value in the matrix coordinate system, based on the Z-axis coordinate value, and Obtain the distance R from the vertical launch vehicle to the origin of the base coordinate system, and then compare R with... cosine value and The product of the cosine values ​​yields the coordinates of the X and Y axes, thus providing the first coordinates in the base station coordinate system.

[0018] Preferably, the angle between the sound rays emitted by the deep-sea vertical vehicle and the X-axis is... for:

[0019] in, Let d be the time difference between the first short-baseline transducer element and the third short-baseline transducer element on the X-axis receiving the underwater acoustic signal from the vertical navigation vehicle. d is the distance between the first short-baseline transducer element and the third short-baseline transducer element, and c is the speed of sound in seawater.

[0020] Preferably, the angle between the sound rays emitted by the deep-sea vertical vehicle and the Y-axis is... for:

[0021] in, Let d be the time difference between the second and fourth short-baseline transducer elements on the Y-axis receiving underwater acoustic signals from the vertical navigation vehicle, respectively. d is the distance between the second and fourth short-baseline transducer elements, and c is the speed of sound in seawater.

[0022] Preferably, based on R and respectively with cosine value and The product of the cosine values ​​yields the first coordinates of the X and Y axes. and They are respectively:

[0023] , , Where L is the vertical distance between the deep-sea vertical vehicle and the docking station.

[0024] Preferably, the electronic control cabin includes:

[0025] A depth pressure gauge, connected to the data processing and control module, is used to obtain depth information of the base station;

[0026] An electronic compass sensor, connected to a data processing and control module, is used to obtain the attitude angle of the docking station;

[0027] The data processing and control module is connected to the underwater acoustic electronics cabin, depth gauge, and electronic compass sensor, respectively. It is used to obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the received deep-sea vertical vehicle and the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the vertical vehicle in the array coordinate system. Based on the docking station's own pose, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference. The relative coordinate is then sent to the underwater acoustic electronics cabin, and then sent by the underwater acoustic electronics cabin to any one of the four short baseline transducer elements.

[0028] The docking station's electrical control module is connected to the underwater acoustic electronic chamber, depth pressure gauge, and electronic compass sensor, respectively, and is used to supply power to the underwater acoustic electronic chamber, depth pressure gauge, and electronic compass sensor.

[0029] The present invention also provides a multi-sensor information positioning system suitable for deep-sea vertical vehicles, including a deep-sea vertical vehicle and the aforementioned docking station;

[0030] The deep-sea vertical vehicle is used to periodically send underwater acoustic signals to the docking station, and is also used to adjust the yaw and pitch angles based on the received relative coordinates of the docking station in the geodetic coordinate system in order to adjust the attitude. It is also used to dock with the docking compartment of the vehicle, to replenish power, and to transmit high-frequency electromagnetic wave signals with the docking station.

[0031] The docking station is used to receive underwater acoustic signals from the deep-sea vertical vehicle, obtain the depth information of the vertical vehicle from the underwater acoustic signals, calculate the incident angle of the vertical vehicle relative to the base station, obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the depth information of the docking station, obtain the first coordinate of the deep-sea vertical vehicle in the array coordinate system based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, convert the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference, based on the pose of the docking station, and send the relative coordinate to the deep-sea vertical vehicle.

[0032] Preferably, the deep-sea vertical vehicle includes, from head to tail, an acoustic-optical guidance module, a buoyancy compensation fuel bladder, a sensor module, an embedded development main control board, an attitude adjustment module and an energy module, a buoyancy adjustment module, an electronic control module, a glider, a tail axial thruster, and a tail radial thruster.

[0033] The acoustic-optical guidance module includes an underwater acoustic communication positioning beacon transceiver transducer and a camera. The underwater acoustic communication positioning beacon transceiver transducer is used to send underwater acoustic signals to the docking station and to receive the relative coordinates of the deep-sea vertical vehicle from the docking station in the geodetic coordinate system with the docking station as the reference. The camera is used to capture optical images and photos during the final stage of docking and send them to the embedded development main control board. After processing the video signal through binarization and image center point calculation algorithms, the deviation data is stably output to compensate for the delay error of the acoustic signal and meet the accuracy requirements of the final docking control.

[0034] The sensor module includes a vehicle altimeter and an inertial measurement unit (IMU). The vehicle altimeter is used to measure the depth of the deep-sea vertical vehicle and transmit the depth of the deep-sea vertical vehicle to the underwater acoustic communication positioning beacon transceiver. The IMU is used to adjust the yaw and pitch angles based on the received relative coordinates in the geodetic coordinate system with the docking station as the reference.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] This invention utilizes four short-baseline transducer elements to construct an array. Using the array coordinate system constructed by this array, the first coordinate of the deep-sea vertical vehicle in the array coordinate system is obtained by receiving the depth information of the vehicle and the docking station and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array. Based on the docking station's own pose, the first coordinate is converted into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference, thereby enabling precise navigation.

[0037] Furthermore, this invention can achieve precise navigation using only one base station. Compared with the existing technology that requires the deployment of multiple base stations, it avoids positioning errors caused by deployment errors and does not require a mother ship carrying the SLIB to assist in positioning on the sea surface. It enables the vehicle to autonomously travel between the sea surface and the seabed for a long time and perform long-term local navigation tasks. Attached Figure Description

[0038] Figure 1 A front view of a connecting station provided for a specific embodiment of the present invention;

[0039] Figure 2 A top view of a connecting station provided in a specific embodiment of the present invention;

[0040] Figure 3 A schematic diagram of the incident angle of a deep-sea vertical vehicle relative to a base station, provided for a specific embodiment of the present invention;

[0041] Figure 4 A structural diagram of a deep-sea vertical navigation vehicle provided for a specific embodiment of the present invention;

[0042] Figure 5 A flowchart illustrating the docking process between a docking station and a deep-sea vertical vehicle during deep-sea submersion is provided for a specific embodiment of the present invention. Detailed Implementation

[0043] To more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0044] like Figure 1 and Figure 2As shown, the present invention proposes a docking station for deep-sea vertical vehicles, including an underwater acoustic transducer 10, an underwater acoustic electronics compartment 11, a vehicle docking compartment 12, and an electronic control compartment 13.

[0045] In this specific embodiment of the invention, the underwater acoustic transducer 10 is located at the top of the docking station. The underwater acoustic transducer includes four short baseline transducer elements. The four short baseline (sbl) transducer elements are on a plane and located at the four vertices of a square, i.e., arranged in a square, thereby constructing an array. The short baseline transducer provided by the present invention is used to receive underwater acoustic signals from the deep-sea vertical vehicle. It can also be used to send the relative coordinates of the deep-sea vertical vehicle calculated by the electronic control cabin in the geodetic coordinate system with the docking station as the reference to the deep-sea vertical vehicle.

[0046] In one specific embodiment, the four short baseline (sbl) transducer elements provided in this embodiment of the invention are array element 1, array element 2, array element 3 and array element 4. The four short baseline transducer elements are distributed counterclockwise at the four corners of the square at the top of the docking station. The two diagonals of the square are used as the X and Y axes, and the intersection of the two diagonals is used as the origin of the array coordinate system. Array element 1 is located on the positive half-axis of the X axis, array element 2 is located on the positive half-axis of the Y axis, array element 3 is located on the negative half-axis of the X axis, and array element 4 is located on the negative half-axis of the Y axis, together forming the sbl array.

[0047] The underwater acoustic electronic cabin 11 provided by this invention is connected to a short-baseline transducer element and is used to obtain the depth information of the deep-sea vertical vehicle from the underwater acoustic signals received by the vehicle, and to transmit the depth information to the electronic control cabin. It is also used to calculate the incident angle of the deep-sea vertical vehicle to the base station based on the time difference between the underwater acoustic data received by different short-baseline transducer elements. Figure 3 As shown, since the element spacing is very small compared to the slant range, it can be considered as a far-field reception case, i.e., the incident angle is parallel to the sound rays of all elements. This invention utilizes an underwater acoustic avionics module based on the array provided in a specific embodiment of the invention to simply and efficiently calculate the incident angle θ of the deep-sea vehicle relative to the base station. The underwater acoustic avionics module provided in the specific embodiment of the invention is also used to provide energy supply to the short-baseline transducer elements.

[0048] In one specific embodiment, the present invention calculates the angle between the acoustic ray emitted by the vertical vehicle and the X-axis based on the distance d between array elements 1 and 3 on the X-axis, and the time difference and phase difference between the underwater acoustic signals received by array elements 1 and 3 from the deep-sea vertical vehicle. The included angle for:

[0049] in, The short-baseline transducer elements on the X-axis, namely the first short-baseline transducer element and the third short-baseline transducer element, namely array element 1 and array element 3, receive the underwater acoustic signals from the vertical navigation vehicle at the time difference, d is the distance between the first short-baseline transducer element and the third short-baseline transducer element, and c is the speed of sound in seawater.

[0050] In a specific embodiment of the present invention, the angle between the acoustic ray emitted by the vertically oriented vehicle and the Y-axis is obtained based on the distance between two short-baseline transducer elements on the Y-axis, and the time and phase differences of the underwater acoustic signals received from the vertically oriented vehicle. The included angle for:

[0051] in, The short-baseline transducer elements on the Y-axis, namely the second short-baseline transducer element and the fourth short-baseline transducer element, namely array element 2 and array element 4, receive the underwater acoustic signals from the vertical navigation vehicle at the time difference, d is the distance between the second short-baseline transducer element and the fourth short-baseline transducer element, and c is the speed of sound in seawater.

[0052] The docking compartment 12 of the present invention is connected to the electronic control compartment 13 and is used to dock with the deep-sea vertical vehicle and transmit electrical energy and high-frequency electromagnetic wave (WIFI) signals to the deep-sea vertical vehicle.

[0053] In a specific embodiment of the present invention, the electronic control cabin 13 is connected to the underwater acoustic electronics cabin 11 and the vehicle docking cabin 12, respectively. It is used to supply power to the underwater acoustic electronics cabin 11 and the vehicle docking cabin 12, and also to obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the depth information of the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the deep-sea vertical vehicle in the array coordinate system. Based on the pose of the docking station, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference, and sends the relative coordinate to any one of the four short baseline transducer elements.

[0054] In one specific embodiment, the electronic control cabin provided by the present invention includes a depth pressure gauge, an electronic compass sensor, a data processing and control module, and a docking station electronic control module. The depth pressure gauge is connected to the data processing and control module and is used to send the obtained depth information of the base station to the data processing and control module.

[0055] The electronic compass sensor provided in this embodiment is connected to the data processing and control module. It is used to send the obtained attitude angle of the docking station to the data processing and control module. It is also used in the preliminary preparation work to perform spatial calibration with the deep-sea vertical vehicle. The ellipsoid fitting method and the tilt compensation method based on the accelerometer are used to eliminate sensor errors (such as hard iron interference, soft iron interference, zero bias, sensitivity error, etc.) to ensure the accuracy of direction measurement. Then, the calibrated docking station is hoisted by the mother ship and deployed in the designated sea area, waiting for it to descend to the seabed to perform long-term observation mission.

[0056] The data processing and control module provided in this embodiment is connected to the underwater acoustic electronics cabin, depth gauge, and electronic compass sensor, respectively. This data processing and control module can obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the received depth information of the deep-sea vertical vehicle and the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the vertical vehicle in the array coordinate system. Based on the docking station's own pose, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference. The relative coordinate is then sent to the underwater acoustic electronics cabin, which controls any one of the four short baseline transducer elements to send a reply to the deep-sea vertical vehicle.

[0057] Specifically, the data processing and control module provided in this embodiment is a computer for data processing and control.

[0058] The docking station electrical control module provided in this embodiment is connected to the underwater acoustic electronic cabin, depth pressure machine and electronic compass sensor respectively, and is used to supply power to the underwater acoustic electronic cabin, depth pressure machine and electronic compass sensor.

[0059] In one specific embodiment, this embodiment uses the vertical distance between the deep-sea vertical vehicle and the docking station as the Z-axis coordinate value in the array coordinate system, based on the Z-axis coordinate value, and Obtain the distance R from the vertical launch vehicle to the origin of the base coordinate system, and then compare R with... cosine value and The product of the cosine values ​​yields the X and Y coordinates, thus providing the first coordinate in the base station coordinate system. and They are respectively:

[0060] , ,, Where L represents the vertical distance between the deep-sea vertical vehicle and the docking station. That is, after the docking station acquires the depth information of the deep-sea vertical vehicle and obtains its own depth information through a depth gauge installed at the docking station, the vertical distance L between the base station and the vehicle can be calculated by subtracting the depth information from the depth information. Therefore, the slant distance R can be calculated, and thus the first coordinate can be determined. At this point, the coordinates of the vehicle in the base station coordinate system can be obtained as follows: The Z-axis is downward, with the positive direction being downward.

[0061] Then, in a specific embodiment of the present invention, the vehicle's attitude angles are obtained through the electronic compass module 13: the angle between the X-axis and the horizontal plane is the pitch angle, the angle between the Y-axis and the horizontal plane is the roll angle, and the angle between the projection of the X-axis onto the horizontal plane and true north is the yaw angle. Therefore, the vehicle's coordinates in the base station coordinate system can be transformed to the geodetic coordinate system n (north, east, ground) using the attitude transformation matrix. Assuming the pitch angle is... The roll angle is yaw angle is Then the attitude transformation matrix is:

[0062]

[0063] Therefore, the coordinates (X, Y, Z) of the vehicle in the geodetic coordinate system with the base station as the origin can be calculated, which gives the vehicle's relative position in the geodetic coordinate system with the base station as the reference point, thus achieving positioning. X represents the northward distance, Y represents the eastward distance, and Z represents the vertical distance. .

[0064] After calculating the coordinates, the docking station provided in this specific embodiment of the invention transmits the calculation results back to the deep-sea vertical vehicle via the SBL array. The deep-sea vertical vehicle can then use the underwater acoustic positioning results for navigation. After obtaining the positioning results in each positioning cycle, the deep-sea vertical vehicle corrects its pitch and yaw angles in real time through the attitude adjustment module 7, controls its course to align with the base station, and finally reaches the seabed to complete a successful docking.

[0065] On the other hand, the present invention also provides a multi-sensor information positioning system suitable for deep-sea vertical vehicles, including a deep-sea vertical vehicle and the aforementioned docking station, wherein:

[0066] The deep-sea vertical vehicle provided in the specific embodiments of the present invention is used to periodically send underwater acoustic signals to the docking station, and is also used to adjust the yaw angle and pitch angle based on the received relative coordinates in the geodetic coordinate system with the docking station as the reference, so as to adjust the attitude. It is also used to dock with the docking compartment of the vehicle and receive high-frequency electromagnetic wave data.

[0067] The specific embodiment of the present invention provides a docking station for receiving underwater acoustic signals from a deep-sea vertical vehicle, obtaining the depth information of the vertical vehicle from the underwater acoustic signals, calculating the incident angle of the vertical vehicle relative to the base station, obtaining the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the depth information of the docking station, obtaining the first coordinate of the deep-sea vertical vehicle in the array coordinate system based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, converting the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference, based on the pose of the docking station, and sending the relative coordinate to the deep-sea vertical vehicle.

[0068] like Figure 4 As shown in the figure, the deep-sea vertical vehicle provided in a specific embodiment of the present invention includes, from head to tail, an acoustic-optical guidance module 9, a buoyancy compensation oil bladder 4, a sensor module 8, an embedded development main control board, an attitude adjustment module and an energy module 7, a buoyancy adjustment module 6, an electronic control module 5, a glider 3, a tail axial thruster 2, and a tail radial thruster 1, wherein:

[0069] The acoustic-optical guidance module 9 provided in a specific embodiment of the present invention includes an underwater acoustic communication positioning beacon transceiver transducer and a camera. The underwater acoustic communication positioning beacon transceiver transducer is used to send underwater acoustic signals to the docking station and to receive the relative coordinates of the deep-sea vertical vehicle from the docking station in the geodetic coordinate system with the docking station as the reference. The camera is used to acquire optical images and take photos during the final stage of docking and send them to the embedded development main control board. Its signal frame rate is 30Hz. After processing the video signal through binarization and image center point calculation algorithms, the deviation data of more than 10Hz is stably output to compensate for the delay error of the acoustic signal and meet the accuracy requirements of the final docking control.

[0070] The sensor module 8 provided in a specific embodiment of the present invention includes a vehicle altimeter and an inertial measurement unit (IMU). The vehicle altimeter is used to measure the depth of the vehicle and send the depth of the vehicle to the underwater acoustic communication positioning beacon transceiver. The inertial measurement unit (IMU) is used to adjust the yaw angle and pitch angle based on the received relative coordinates in the geodetic coordinate system with the docking station as the reference.

[0071] The attitude adjustment module and energy module 7 provided in the specific embodiments of the present invention change the stable attitude of the vehicle by changing the relative position of the vehicle's center of gravity and center of buoyancy by sliding the attitude module on the guide rail, thereby realizing attitude adjustment technology based on center of gravity adjustment.

[0072] The buoyancy adjustment module 6 provided in a specific embodiment of the present invention includes a pump, a motor and a valve, and adopts a hydraulic drive adjustment method to realize buoyancy adjustment under high pressure environment.

[0073] The power control module 5 provided in the specific embodiment of the present invention is a bottom-level main control circuit board based on the STM32 chip, mainly used for communication and power supply.

[0074] In a specific embodiment of the present invention, the thrust and direction of motion of a deep-sea vertical vehicle are controlled by a glider, a tail axial thruster, and a tail radial thruster. The tail radial thruster is used to provide radial thrust, and the tail axial thruster is used to provide axial thrust.

[0075] This invention takes a deep-sea dive and docking at a depth of 6,000 meters as an example, such as... Figure 5 As shown, the positioning process is as follows:

[0076] To ensure successful positioning, preliminary preparations are necessary: ​​First, the IMU measurement unit 8 of the vehicle and the electronic compass 13 of the docking base station are spatially calibrated using ellipsoidal fitting and accelerometer-based tilt compensation methods to eliminate sensor errors (such as hard iron interference, soft iron interference, zero bias, and sensitivity errors) to ensure the accuracy of direction measurements. Then, the calibrated docking base station is deployed from the mother ship to a designated sea area, awaiting its descent to the seabed for long-term observation.

[0077] In a specific embodiment of this invention, the deep-sea vertical vehicle receives a docking command via satellite. The buoyancy adjustment module 6 performs an oiling operation to reduce buoyancy and begin descent. The sensor module 8 reads sensor information at a set frequency, and reads acceleration, angular velocity, and the vehicle's attitude angle via the IMU. Underwater acoustic positioning employs a response mechanism. The vehicle periodically transmits its current depth value to the seabed via the underwater acoustic communication positioning beacon transceiver 9. When the four transceivers 10 of the seabed docking base station receive the underwater acoustic signals transmitted by the vehicle, the underwater acoustic electronics compartment 11 obtains the vehicle's depth information through the received underwater acoustic data and calculates the azimuth and pitch angles of the vehicle relative to the array using phase difference and time difference. Since the element spacing is very small compared to the slant range, it can be considered a far-field reception situation, i.e., the incident angle is parallel to the sound rays of all elements.

[0078] The spacing between array elements 1 and 3, and between array elements 2 and 4, provided in the specific embodiments of this invention for underwater acoustic communication positioning are all... Utilizing the time difference between the signals received by array element 1 and array element 3 The speed of sound propagation *c* in seawater can be used to calculate the angle between the sound ray emitted by the transceiver of the underwater acoustic communication positioning beacon and the x-axis. :

[0079]

[0080] Utilizing the time difference between the signals received by array element 2 and array element 4 The speed of sound propagation *c* in seawater can be used to calculate the angle between the sound ray emitted by the transceiver of the underwater acoustic communication positioning beacon and the y-axis. :

[0081]

[0082] Assuming the distance from the transceiver transducer of the underwater acoustic communication positioning beacon to the origin of the underwater acoustic communication positioning array is the slant range R, then the x and y coordinates of the transceiver transducer in the array coordinate system are... , for:

[0083] ,

[0084] Specific embodiments of the present invention provided The horizontal and vertical axes of the underwater acoustic communication positioning beacon transceiver are combined. , and the distance to the plane containing the four elements of the underwater acoustic communication positioning array The relationship is:

[0085]

[0086] Considering the directivity of the underwater acoustic communication positioning array, the underwater acoustic communication positioning beacon can only move above the four array elements, i.e., the positive z-axis. Therefore:

[0087]

[0088] Once the docking base station obtains the depth information of the aircraft and acquires its own depth information via a depth gauge installed on the base station, the vertical distance L between the base station and the aircraft can be calculated by subtracting the two measurements. Therefore, the slant range can be calculated. And then calculate , At this point, the coordinates of the vehicle in the base station coordinate system can be obtained as ( The Z-axis points downwards as the positive direction. Then, the vehicle's attitude angles are obtained through the electronic compass module 13: the angle between the X-axis and the horizontal plane is the pitch angle, the angle between the Y-axis and the horizontal plane is the roll angle, and the angle between the projection of the X-axis onto the horizontal plane and true north is the yaw angle. Therefore, the vehicle's coordinates in the base station coordinate system can be transformed to the geodetic coordinate system n (north, east, ground) using the attitude transformation matrix. Assuming the pitch angle is... The roll angle is yaw angle is Then the attitude transformation matrix is:

[0089]

[0090] Therefore, the coordinates (X, Y, Z) of the vehicle in the geodetic coordinate system with the base station as the origin can be calculated, which gives the vehicle's relative position in the geodetic coordinate system with the base station as the reference point, thus achieving positioning. X represents the northward distance, Y represents the eastward distance, and Z represents the vertical distance.

[0091] .

[0092] After the docking station calculates the coordinates, it transmits the results back to the vehicle via the SBL array, allowing the vehicle to navigate using the underwater acoustic positioning. After obtaining the positioning result in each positioning cycle, the vehicle uses attitude adjustment module 7 to adjust its pitch and yaw angles in real time, controlling its course to align with the base station, and finally reaching the seabed to complete a successful docking.

[0093] The present invention specifically designs a deep-sea vertical vehicle and a vertical docking base station. Compared with horizontal vehicles, the vertically profiled vehicle can more efficiently and accurately perform localized navigation tasks between the surface and the seabed docking base station. It can reduce energy consumption through buoyancy adjustment, overcome drift caused by ocean currents, and increase the docking success rate.

[0094] A specific embodiment of this invention proposes a multi-sensor information positioning system suitable for deep-sea vertical vehicles. This system fully utilizes information from multiple sensors mounted on the vehicle and the base station: depth barometer, electronic compass, IMU, and SBL. It uses an embedded minicomputer for data analysis and processing, and completes large-scale underwater communication through acoustic SBL. Finally, it obtains the three-dimensional coordinates of the vehicle in the geodetic coordinate system with the base station as the origin, thus achieving precise navigation.

[0095] In a specific embodiment of the present invention, only four acoustic array transducers need to be installed at a fixed location on a base station, and the base station is deployed in a fixed sea area where long-term observation tasks need to be performed. This eliminates the need for deploying four or more base stations, thus avoiding positioning errors caused by deployment mistakes. Furthermore, it eliminates the need for a mother ship carrying the SLIB to assist in positioning on the sea surface, enabling the vehicle to autonomously travel between the sea surface and the seabed for extended periods, performing long-term localized navigation tasks.

[0096] The specific embodiments of this invention employ the aforementioned multi-sensor information positioning system for docking stations, which can efficiently and accurately help deep-sea vertical vehicles obtain the relative position of the docking station. The effective positioning distance exceeds six kilometers, reducing energy consumption lost during docking and improving the success rate of docking. It is suitable for autonomous navigation of deep-sea vertical vehicles, enabling long-term intelligent, localized navigation missions between surface and seabed docking stations. Furthermore, this positioning system has good portability and reusability. For other deep-sea positioning and navigation environments, redundancy can be achieved by increasing the number and types of sensors, such as strapdown inertial navigation systems, optical cameras, and sonar detectors. Adding sensor information to the system according to specific circumstances increases positioning accuracy and eliminates positioning errors.

Claims

1. A docking station for deep-sea vertical transport vehicles, characterized in that, include: The underwater acoustic transducer includes four short-baseline transducer elements arranged in a square to form an array. The short-baseline transducer elements are used to receive underwater acoustic signals from the deep-sea vertical vehicle and to transmit the relative coordinates of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference point to the deep-sea vertical vehicle. The underwater acoustic electronic cabin is connected to the short baseline transducer element and is used to supply power to the underwater acoustic transducer and send commands. It is used to obtain the depth information of the deep-sea vertical vehicle from the underwater acoustic signal and to calculate the incident angle of the deep-sea vertical vehicle to the base station based on the time difference of receiving underwater acoustic data by different short baseline transducer elements. The docking compartment of the vehicle is connected to the electronic control compartment and is equipped with a wireless charging coil for docking with the deep-sea vertical vehicle and transmitting electrical energy and high-frequency electromagnetic wave signals to the deep-sea vertical vehicle. The electronic control cabin is connected to the underwater acoustic transducer, the underwater acoustic electronics cabin, and the vehicle docking cabin. It is used to supply power to the underwater acoustic electronics cabin and the vehicle docking cabin. It is also used to obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the depth information of the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the deep-sea vertical vehicle in the array coordinate system. Based on the pose of the docking station, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference. It then sends the relative coordinate to any one of the four short baseline transducer elements. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, the first coordinates of the vertical vehicle in the base station coordinate system are obtained, including: The diagonals formed by connecting every two short baseline transducer elements at the four vertices of the square are used as the X-axis and Y-axis, respectively, and the intersection of the two diagonals is used as the origin of the matrix coordinate system. The angle between the acoustic ray emitted by the vertically oriented vehicle and the X-axis is obtained based on the distance between the two short-baseline transducer elements on the X-axis and the time difference between the underwater acoustic signals received from the deep-sea vertical vehicle. ; The angle between the acoustic ray emitted by the vertically oriented vehicle and the Y-axis is obtained based on the distance between two short-baseline transducer elements on the Y-axis and the time difference of the received underwater acoustic signal from the vertically oriented vehicle. ; Using the vertical distance between the deep-sea vertical vehicle and the docking station as the Z-axis coordinate value in the matrix coordinate system, based on the Z-axis coordinate value, and Obtain the distance R from the vertical launch vehicle to the origin of the base coordinate system, and then compare R with... cosine value and The product of the cosine values ​​yields the coordinates of the X and Y axes, thus obtaining the first coordinates in the base station coordinate system; A multi-sensor information positioning system suitable for deep-sea vertical vehicles includes the deep-sea vertical vehicle and the aforementioned docking station; The deep-sea vertical vehicle is used to periodically send underwater acoustic signals to the docking station, and is also used to adjust the yaw and pitch angles based on the received relative coordinates of the docking station in the geodetic coordinate system in order to adjust the attitude. It is also used to dock with the docking compartment of the vehicle, to replenish power, and to transmit high-frequency electromagnetic wave signals with the docking station. The docking station is used to receive underwater acoustic signals from the deep-sea vertical vehicle, obtain the depth information of the vertical vehicle from the underwater acoustic signals, calculate the incident angle of the vertical vehicle relative to the base station, obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the deep-sea vertical vehicle and the depth information of the docking station, obtain the first coordinate of the deep-sea vertical vehicle in the array coordinate system based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, convert the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference, based on the pose of the docking station, and send the relative coordinate to the deep-sea vertical vehicle.

2. The docking station for deep-sea vertical vehicles according to claim 1, characterized in that, The angle between the sound rays emitted by the deep-sea vertical navigation vehicle and the X-axis for: in, Let d be the time difference between the first short-baseline transducer element and the third short-baseline transducer element on the X-axis receiving the underwater acoustic signal from the vertical navigation vehicle. d is the distance between the first short-baseline transducer element and the third short-baseline transducer element, and c is the speed of sound in seawater.

3. The docking station for deep-sea vertical vehicles according to claim 1, characterized in that, The angle between the sound emitted by the deep-sea vertical navigation vehicle and the Y-axis for: in, Let d be the time difference between the second and fourth short-baseline transducer elements on the Y-axis receiving underwater acoustic signals from the vertical navigation vehicle, respectively. d is the distance between the second and fourth short-baseline transducer elements, and c is the speed of sound in seawater.

4. The docking station for deep-sea vertical vehicles according to claim 1, characterized in that, Based on R and respectively cosine value and The product of the cosine values ​​yields the first coordinates of the X and Y axes. and They are respectively: , , Where L is the vertical distance between the deep-sea vertical vehicle and the docking station.

5. The docking station for deep-sea vertical vehicles according to claim 1, characterized in that, The electronic control cabin includes: A depth pressure gauge, connected to the data processing and control module, is used to obtain depth information of the base station; An electronic compass sensor, connected to a data processing and control module, is used to obtain the attitude angle of the docking station; The data processing and control module is connected to the underwater acoustic electronics cabin, depth gauge, and electronic compass sensor, respectively. It is used to obtain the vertical distance between the deep-sea vertical vehicle and the docking station based on the depth information of the received deep-sea vertical vehicle and the docking station. Based on the vertical distance and the incident angle of the deep-sea vertical vehicle relative to the underwater acoustic array, it obtains the first coordinate of the vertical vehicle in the array coordinate system. Based on the docking station's own pose, it converts the first coordinate into the relative coordinate of the deep-sea vertical vehicle in the geodetic coordinate system with the docking station as the reference. The relative coordinate is then sent to the underwater acoustic electronics cabin, and then sent by the underwater acoustic electronics cabin to any one of the four short baseline transducer elements. The docking station's electrical control module is connected to the underwater acoustic electronic chamber, depth pressure gauge, and electronic compass sensor, respectively, and is used to supply power to the underwater acoustic electronic chamber, depth pressure gauge, and electronic compass sensor.

6. The multi-sensor information positioning system for deep-sea vertical vehicles according to claim 1, characterized in that, The deep-sea vertical vehicle, from head to tail, includes an acoustic-optical guidance module, a buoyancy compensation fuel bladder, a sensor module, an embedded development main control board, an attitude adjustment module and an energy module, a buoyancy adjustment module, an electronic control module, a glider, a tail axial thruster, and a tail radial thruster. The acoustic-optical guidance module includes an underwater acoustic communication positioning beacon transceiver transducer and a camera. The underwater acoustic communication positioning beacon transceiver transducer is used to send underwater acoustic signals to the docking station and to receive the relative coordinates of the deep-sea vertical vehicle from the docking station in the geodetic coordinate system with the docking station as the reference. The camera is used to capture optical images and photos during the final stage of docking and send them to the embedded development main control board. After processing the video signal through binarization and image center point calculation algorithms, the deviation data is stably output to compensate for the delay error of the acoustic signal and meet the accuracy requirements of the final docking control. The sensor module includes a vehicle altimeter and an inertial measurement unit (IMU). The vehicle altimeter is used to measure the depth of the deep-sea vertical vehicle and transmit the depth of the deep-sea vertical vehicle to the underwater acoustic communication positioning beacon transceiver. The IMU is used to adjust the yaw and pitch angles based on the received relative coordinates in the geodetic coordinate system with the docking station as the reference.

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