An intelligent control method and system for underwater dual-platform docking and lifting operations

Abstract

The present invention discloses an intelligent control method and system for underwater dual-platform docking and hoisting operations, and relates to the field of intelligent control of underwater dual-platform docking and hoisting operations. The system includes an underwater dual platform and a host computer for controlling the underwater dual platform. The underwater dual platform includes a mother boat and a hoisting robot for docking and hoisting a target object. The mother boat carries a winch and a hoisting robot. When docking with the target object, the mother boat is in a preset hovering position and deploys the hoisting robot. In the process of deploying the hoisting robot, the position state of the hoisting robot is adjusted based on the horizontal relative position between the hoisting robot and the target object until the hoisting robot is aligned with the target object and docks with the target object. After the hoisting robot docks with the target object, the host computer hoists and recovers the hoisting robot and the target object. The system has a high degree of intelligence, effectively reduces the control load, and improves the accuracy and efficiency of the target object docking control.

Description

Technical Field

[0001] The present invention relates to the field of intelligent control of cooperative docking and lifting operations of underwater dual platforms, and in particular to an intelligent control method and system for cooperative docking and lifting operations of underwater dual platforms. Background Art

[0002] In the ocean, full underwater search, docking and lifting and recovery of underwater docking boxes, sunken electronic cabins and other friendly targets is a new operation mode, which has the advantages of concealment and not being affected by sea waves. Generally, this operation mode uses a large underwater mother ship equipped with a lifting robot to carry out underwater dual-platform collaborative operations.

[0003] The underwater mothership is equipped with an inertial navigation system, depth gauge, altimeter, equalizing tank, etc. The mothership can detect its own absolute position and also has the ability of fixed-point power control and precise injection and drainage adjustment;

[0004] The lifting robot is equipped with beacons, cameras, and docking tools such as grabbing or magnetic suction cups. The lifting robot also has the ability to adjust the horizontal position and heading. The beacon can detect its relative position with the mother ship, and the camera shooting information on the lifting robot can be uploaded to the mother ship for control and observation.

[0005] The mother boat uses the winch on board to retract and release the lifting robot, and the winch's cable retraction and release speed can be adjusted in real time. Traditionally, the operator generally controls the underwater mother boat, winch and lifting robot, and observes the position of the target object through a camera during the terminal docking process. However, the entire underwater deployment and lifting process is time-consuming, the operation instructions are cumbersome, the control load is heavy, and manual control is difficult to estimate based on the current environment, relative position and other information, and cannot achieve high-precision and efficient target object docking control. Summary of the invention

[0006] In view of the above problems and technical requirements, the inventors have proposed an intelligent control method and system for underwater dual-platform docking and lifting operations. The technical solution of the present invention is as follows:

[0007] An intelligent control method for underwater dual-platform docking and lifting operations, providing an underwater dual-platform and a host computer for controlling the underwater dual-platform, wherein the underwater dual-platform includes a mother boat and a lifting robot for docking and lifting a target object, wherein:

[0008] The mother boat is equipped with a winch and a lifting robot. The lifting robot is connected to the winch through a cable. The host computer controls the winch to release and retract the cable to deploy and lift the lifting robot.

[0009] Based on the position information of the mother boat and the position information of the target object, the host computer configures the preset hovering position of the mother boat, so that when the mother boat is in the preset hovering position, the placement point of the lifting robot under the action of the ocean current corresponds to the target object;

[0010] When docking with a target object, the mother boat is in a preset hovering position and deploys the lifting robot. During the deployment of the lifting robot, the position state of the lifting robot is adjusted based on the horizontal relative position between the lifting robot and the target object until the lifting robot is aligned with the target object and docks with the target object.

[0011] After the lifting robot docks with the target object, the host computer lifts and recovers the lifting robot and the target object.

[0012] A further solution is that when docking with the target object, the first docking stage, the second docking stage and the third docking stage are performed in sequence, wherein:

[0013] During the first stage of docking, the host computer controls the mother ship to move to the preset hovering position and deploys the lifting robot, and confirms the first deployment point based on the horizontal relative position between the lifting robot and the target object, so that the horizontal relative distance between the first deployment point of the lifting robot and the target object is less than or equal to the movement radius R of the lifting robot;

[0014] During the second stage of docking, the host computer deploys the lifting robot and determines the second deployment point based on the horizontal relative position between the lifting robot and the target object, so that the second deployment point of the lifting robot is located directly above the target object;

[0015] During the third docking phase, the host computer deploys the lifting robot so that the lifting robot docks with the target object.

[0016] A further solution is that it also includes a positioning unit for positioning during docking, wherein:

[0017] The positioning unit includes an ultra-short baseline positioning module and a visual positioning module, wherein:

[0018] The ultra-short baseline positioning module performs ultra-short baseline positioning on the lifting robot to obtain the horizontal relative position between the lifting robot and the mother ship;

[0019] The ultra-short baseline positioning module includes an ultra-short baseline transducer and an ultra-short baseline beacon. The ultra-short baseline transducer is installed on the mother ship, and the ultra-short baseline beacon is installed on the lifting robot.

[0020] The visual positioning module performs visual positioning on the target object, including an underwater camera and a positioning marker. The underwater camera is installed on the lifting robot, and the positioning marker is installed on the target object. When the underwater camera captures an image containing the positioning marker, the host computer identifies and locates the positioning marker in the image, and obtains the horizontal relative position between the lifting robot and the target object based on the identification and positioning results.

[0021] A further solution is that the mother boat position information at least includes the hovering depth d of the mother boat. u The location information of the target object at least includes the three-dimensional coordinates (x t ,y t , d t );

[0022] When configuring the preset hovering position, the host computer sets the length of the winch cable after the target object docks to L. i , and the cable length is L i The three-dimensional coordinates of the relative position between the lifting robot and the mother ship (δx i ,δy i ,δz i ), for the cable length L i Calculate, then:

[0023]

[0024] Where η is the iterative calculation convergence parameter and 0≤η≤1, i is the number of iterations, L i-1 is the cable length calculated for the i-1th time, δz i-1 The cable length is L i-1 The z-axis coordinate value of the three-dimensional coordinates of the relative position of the lifting robot and the mother boat;

[0025] Calculate the cable length as L i The relative distance h between the lifting robot and the target object in the z-axis direction i , then:

[0026] h i =|d t -d u -δz i |

[0027] If h i Less than the set threshold h dead , then based on the cable length L i The relative position of the lifting robot and the mother boat is used to obtain the three-dimensional coordinates (x i ,y i , z i ), then:

[0028]

[0029] A further solution is to obtain the two-dimensional coordinates (x e ,y e ), and determine the horizontal relative distance d between the lifting robot and the target object;

[0030] If the horizontal relative distance d is greater than the motion radius R of the lifting robot, the host computer controls the mother ship to move to the calibration hovering position, and the lifting robot moves with the mother ship. The position of the lifting robot after moving is used as the first placement point, where the three-dimensional coordinates of the calibration hovering position (x q ,y q , z q ) can be expressed as:

[0031]

[0032] A further solution is to perform coarse alignment and fine alignment on the target object in sequence when confirming the second placement point, wherein:

[0033] When the target object is roughly aligned, the host computer obtains the horizontal relative position of the lifting robot and the mother ship through ultra-short baseline positioning, and obtains the horizontal relative position deviation of the lifting robot and the target object based on the horizontal relative position of the lifting robot and the mother ship and the position information of the target object;

[0034] Based on the horizontal relative position deviation between the lifting robot and the target object, the host computer moves the lifting robot through fixed-point control until the horizontal relative position deviation between the lifting robot and the target object matches the first deviation threshold s1;

[0035] When the target object is precisely aligned, the lifting robot is deployed until the upper computer obtains the horizontal relative position deviation between the lifting robot and the target object through visual positioning;

[0036] Based on the horizontal relative position deviation between the lifting robot and the target object, the upper computer moves the lifting robot through fixed-point control until the horizontal relative position deviation between the lifting robot and the target object matches the second deviation threshold s2, and uses the position of the lifting robot at this time as the second placement point.

[0037] A further solution is that the horizontal relative position deviation between the lifting robot and the target object includes a position deviation in a first axis direction and a position deviation in a second axis direction, wherein the first axis is perpendicular to the second axis;

[0038] Fixed-point control includes calculating the expected thrust in the first-axis direction of the lifting robot based on the position deviation between the lifting robot and the target object in the first-axis direction, and calculating the expected thrust in the second-axis direction of the lifting robot based on the position deviation between the lifting robot and the target object in the second-axis direction. The upper computer controls the movement of the lifting robot based on the expected thrust in the first-axis direction of the lifting robot and the expected thrust in the second-axis direction of the lifting robot.

[0039] The further solution is that the host computer obtains the maximum cable release speed v of the winch max , and control the cable release speed of the winch in the first docking stage, the second docking stage and the third docking stage, wherein,

[0040] In the first stage of docking, the winch is operated at the maximum cable release speed v max Cable laying;

[0041] In the second stage of docking, the winch releases the cable at speed v1 before confirming the second deployment point, and releases the cable at speed v2 when confirming the second deployment point;

[0042] In the third docking phase, the winch releases the cable at a speed v2, where

[0043] Speed ​​v1 = k1v max , speed v2=k2v max , k1 is the first speed coefficient, k2 is the second speed coefficient, and k2≤k1≤1.

[0044] A further solution is that when recovering the target object, the host computer controls the winch to reel in the cable at a speed of v3 until the height of the lifting robot from the seabed is greater than the length L of the lifting robot itself. r After that, the host computer increases the winch's cable-receiving speed to the maximum cable-releasing speed v max ;

[0045] The distance between the lifting robot and the mother ship is less than the first safety distance L r1 After that, the host computer reduces the winch's cable-receiving speed to speed v4, where L r1 =m1L r , m1 is the first safety distance coefficient;

[0046] The distance between the lifting robot and the mother ship is less than the second safety distance L r2 After that, the host computer reduces the winch's retracting speed to speed v3, and stops retracting when the cable length is less than the cable length safety setting value, completing the lifting and recovery of the target object. r2 =m2L r , m2 is the second safety distance coefficient.

[0047] An intelligent control system for underwater dual-platform docking and lifting operations includes underwater dual platforms and a host computer for controlling the collaborative operation of the underwater dual platforms. The underwater dual platforms include a mother boat and a lifting robot for docking and lifting a target object.

[0048] The host computer is installed on a mother boat equipped with a lifting robot and a winch. Based on the above intelligent control method, the host computer controls the status of the mother boat and the lifting robot to control the lifting robot to dock with the target object and lift and recover the target object.

[0049] The beneficial technical effects of the present invention are:

[0050] Provided is an intelligent control method and system for underwater dual-platform docking and lifting operations. The system configures a preset hovering position of a mother boat based on the position information of the mother boat and the position information of a target object, so that when the mother boat is in the preset hovering position, the placement point of the lifting robot under the action of the ocean current corresponds to the target object, thereby effectively improving the efficiency of underwater docking and lifting.

[0051] The control system includes an ultra-short baseline positioning module and a visual positioning module. The ultra-short baseline positioning module is used to perform ultra-short baseline positioning on the lifting robot to obtain the horizontal relative position of the lifting robot and the mother boat; the visual positioning module is used to perform visual positioning on the target object to obtain the horizontal relative position of the target object and the lifting robot. When docking with the target object, the host computer controls the mother boat to be in a preset hovering position and deploys the lifting robot. In the process of deploying the lifting robot, the target object is first roughly aligned based on the ultra-short baseline positioning, and then the target object is precisely aligned based on the visual positioning, so that the lifting robot is aligned with the target object and docks the lifting target object. The control system does not need to be estimated by combining the current environment, relative position and other information manually, and realizes the automatic control of the whole process of docking and lifting the target object, improves the accuracy of the target object alignment, and has a high degree of intelligence. In addition, the control system automatically realizes the switching from coarse alignment to fine alignment. The operator only needs to input the configuration parameters, and no additional manual operation is required, which effectively reduces the control load, improves the applicability of the control system, and realizes efficient and high-precision docking control of the target object. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural schematic diagram of an embodiment of an intelligent control system for underwater dual-platform docking and lifting operations provided by the present application.

[0053] Explanation of the reference numerals: 101-host computer, 102-current meter, 1031-ultra-short baseline transducer, 1032-ultra-short baseline beacon, 104-underwater camera, 105-positioning marker, 200-mother boat, 201-underwater mother boat navigation control subsystem, 202-winch, 2021-winch control subsystem, 2022-cable, 300-lifting robot, 301-lifting robot control subsystem, 400-target object. DETAILED DESCRIPTION

[0054] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0055] In order to improve the docking accuracy and operation efficiency of underwater docking and lifting operations, the present invention proposes an intelligent control method for underwater dual-platform docking and lifting operations, providing an underwater dual platform and a host computer 101 for controlling the underwater dual platform, wherein the underwater dual platform includes a mother boat 200 and a lifting robot 300 for docking and lifting a target object, wherein:

[0056] The mother boat 200 carries a winch 202 and a lifting robot 300. The lifting robot 300 is connected to the winch 202 via a cable 2022. The host computer 101 controls the winch 202 to release and retract the cable, so as to deploy and lift and recover the lifting robot 300.

[0057] Based on the position information of the mother boat 200 and the position information of the target object 400, the host computer 101 configures the preset hovering position of the mother boat 200, so that when the mother boat 200 is in the preset hovering position, the placement point of the lifting robot 300 under the action of the ocean current corresponds to the target object 400;

[0058] When docking with the target object, the mother boat 200 is in a preset hovering position and deploys the lifting robot 300. In the process of deploying the lifting robot 300, the position state of the lifting robot 300 is adjusted based on the horizontal relative position between the lifting robot 300 and the target object 400 until the lifting robot 300 is aligned with the target object 400 and docks with the target object 400.

[0059] After the lifting robot 300 docks with the target object 400 , the host computer 101 lifts and recovers the lifting robot 300 and the target object 400 .

[0060] In one embodiment of the present invention, the underwater dual platform specifically refers to an underwater platform formed based on a mother boat 200 and an underwater platform formed based on a lifting robot 300. The mother boat 200 has the functions described in the background technology and will not be repeated here. Generally, the mother boat 200 is equipped with a winch 202 and a lifting robot 300. The mother boat 200 is provided with an underwater mother boat navigation control subsystem 201 for controlling the navigation state of the mother boat 200. The winch 202 is provided with a winch control subsystem 2021 for controlling the cable retracting and releasing state of the winch 202. The lifting robot 300 is provided with a lifting robot control subsystem 301 for controlling the motion state of the lifting robot 200.

[0061] The host computer 101 can generally be a control computer, such as Figure 1 As shown, the host computer 101 is installed on the mother boat 200, and is connected to the underwater mother boat navigation control subsystem 201, the winch control subsystem 2021 and the lifting robot control subsystem 301 through a bus or a network to control the status of the mother boat 200, the winch 202 and the lifting robot 300; the winch 202 is connected to the winch 202 through a cable 2022, and preferably, the cable 2022 can be a composite cable; the host computer 101 controls the winch 202 to release and reel in the cable to deploy and lift and recover the lifting robot 300.

[0062] Generally, before docking with the target object 400, there is a large distance between the hovering position of the mother boat 200 and the target object 400 in the horizontal direction. In order to make the initial deployment point of the lifting robot 300 closer to the target object 400 in the horizontal direction and improve the docking efficiency, the mother boat 200 needs to be moved to the preset hovering position before deploying the lifting robot 300. The specific method of configuring the preset hovering position can refer to the following implementation method.

[0063] When the mother boat 200 is in the preset hovering position, the placement point of the lifting robot 300 under the action of the ocean current corresponds to the target object 400. Specifically, the correspondence means that the placement point of the lifting robot 300 is located directly above or near the target object 400; wherein, directly above specifically means that the center of gravity of the lifting robot 300 and the center of gravity of the target object 400 are located in the same straight line in the vertical direction. When the placement point of the lifting robot 300 is located near the top of the target object 400, the horizontal relative distance between the placement point of the lifting robot 300 and the target object 400 is less than or equal to the movement radius R of the lifting robot 300, and the movement radius R corresponds to the maximum range of movement of the lifting robot in the horizontal plane.

[0064] When docking with the target object, the mother boat 200 is in a preset hovering position and the lifting robot 300 is deployed. During the deployment of the lifting robot 300, based on the horizontal relative position between the lifting robot 300 and the target object 400, the upper computer 105 adjusts the position state of the lifting robot 300 by controlling the underwater mother boat navigation control subsystem 201, the winch control subsystem 2021 and the lifting robot control subsystem 301 until the lifting robot 300 is located directly above the target object 400, that is, the lifting robot 300 is aligned with the target object 400, and docks with the target object 400.

[0065] The horizontal relative position between the lifting robot 300 and the target object 400 is the relative position between the projection of the lifting robot 300 and the target object 400 when the lifting robot 300 is projected onto the plane where the target object 400 is located. The lifting robot 300 can use a docking tool such as a mechanical arm or a magnetic suction cup. The docking tool docks the target object 400 through a docking lifting point set on the target object 400. The center point of the docking tool and the center of gravity of the lifting robot 300 are located in the same straight line in the vertical direction, and the docking lifting point and the center of gravity of the target object 400 are also located in the same straight line in the vertical direction. Therefore, when the lifting robot 300 and the target object 400 are aligned, the center point of the docking tool is aligned with the docking lifting point to dock the target object 400. In specific implementation, the docking tool can be selected according to the actual needs of docking the target object 400. Although some existing docking tools have a certain tolerance range for alignment, the docking of the target object 400 can also be completed when the center point of the docking tool is not aligned with the docking lifting point. However, in the case of misalignment, the centers of gravity of the lifting robot 300 and the target object 400 are not located in the same straight line in the vertical direction, and the docking stability is poor due to the influence of the ocean current during the lifting and recovery process. Therefore, in order to maintain the stability of the docking during the lifting and recovery process, it is necessary to align the lifting robot 300 and the target object 400 during the docking process.

[0066] After the lifting robot 300 docks with the target object 400 , the host computer 101 controls the winch to reel in the cable through the winch control subsystem 2021 , and lifts and recovers the lifting robot 300 and the target object 400 .

[0067] Furthermore, in an embodiment of the present invention, when docking with a target object, a first docking stage, a second docking stage, and a third docking stage are sequentially performed, wherein:

[0068] During the first stage of docking, the host computer 105 controls the mother boat 200 to move to a preset hovering position and deploys the lifting robot 300, and confirms the first deployment point based on the horizontal relative position between the lifting robot 300 and the target object 400, so that the horizontal relative distance between the first deployment point of the lifting robot 300 and the target object 400 is less than or equal to the movement radius R of the lifting robot 300;

[0069] During the second docking phase, the host computer 105 deploys the lifting robot 300, and determines a second deployment point based on the horizontal relative position between the lifting robot 300 and the target object 400, so that the second deployment point of the lifting robot is located directly above the target object 400;

[0070] During the third docking stage, the host computer 105 deploys the lifting robot 300 so that the lifting robot 300 docks with the target object 400 .

[0071] Specifically, the lifting robot 300 is equipped with an altimeter, which can obtain the height h of the lifting robot 300 from the seabed in real time and feed it back to the host computer 105. During the first stage of docking, the host computer 105 controls the mother boat 200 to move to a preset hovering position, and controls the winch 202 to release the cable and deploy the lifting robot 300 through the winch control subsystem 2021. At the same time, the height h of the lifting robot 300 from the seabed is determined by the altimeter. When the height h of the lifting robot 300 from the seabed is less than the first height setting value h set1 When the winch 202 stops releasing the cable, and waits until the motion state of the lifting robot 300 is stable, that is, the position of the lifting robot 300 remains unchanged, the position of the lifting robot 300 at this time is used as the first placement point.

[0072] During specific operation, affected by the current velocity, current direction and other environmental factors, when the mother boat 200 is in the preset hovering position, the horizontal relative distance between the first placement point of the lifting robot 300 under the action of the current and the target object 400 may be greater than the movement radius R of the lifting robot 300, so it is necessary to refer to the following specific implementation to confirm the first placement point of the lifting robot 300. In one embodiment of the present invention, the first height setting value h set1 =20L r , L r is the length of the lifting robot itself. In specific implementation, the first height setting value h set1 The selection can be made according to actual needs, with the specific standard being whether it can meet the confirmation of the first deployment landing point.

[0073] In the second stage of docking, based on the confirmed first placement point, the winch 202 continues to release the cable to place the lifting robot 300. When the height h of the lifting robot 300 from the seabed is less than the second height setting value h set2 When the winch 202 stops releasing the cable, based on the horizontal relative position between the lifting robot 300 and the target object 400, the host computer 101 adjusts the horizontal position of the lifting robot 300 to confirm the second placement point of the lifting robot 300. The second placement point is located directly above the target object 400. At this time, the lifting robot 300 and the target object 400 are aligned. The method for confirming the second placement point can refer to the following specific implementation. The second height setting value h set2 =5L r , in specific implementation, the second height setting value h set2 The selection can be made according to actual needs, with the specific standard being whether it can meet the confirmation of the second deployment landing point.

[0074] In one embodiment of the present invention, when the second placement point of the lifting robot 300 is located directly above the target object 400, there is still a small distance between the lifting robot 300 and the target object 400 in the vertical direction, that is, the lifting robot 300 and the target object 400 are not in contact, so when performing the third stage of docking, it is necessary to control the winch 202 to continue to release the cable to place the lifting robot 300 based on the second placement point. When the height h of the lifting robot 300 from the seabed is less than the third height setting value h set3 When the winch 202 stops releasing the cable, the host computer 105 controls the lifting robot 300 to dock the target object 400. The third height setting value h set3 =0.3L r , in specific implementation, the third height setting value h set3 The selection may be made according to actual needs, with the docking with the target object 400 being the specific standard.

[0075] Furthermore, in the first docking stage and the second docking stage, positioning is performed using a positioning unit, the positioning unit comprising an ultra-short baseline positioning module and a visual positioning module, wherein:

[0076] The ultra-short baseline positioning module performs ultra-short baseline positioning on the lifting robot 300 to obtain the horizontal relative position between the lifting robot 300 and the mother boat 200;

[0077] The ultra-short baseline positioning module includes an ultra-short baseline transducer 1031 and an ultra-short baseline beacon 1032 . The ultra-short baseline transducer 1031 is installed on the mother boat 200 , and the ultra-short baseline beacon 1032 is installed on the lifting robot 300 .

[0078] The visual positioning module performs visual positioning on the target object 400, and includes an underwater camera 104 and a positioning marker 105. The underwater camera 104 is installed on the lifting robot 300, and the positioning marker 105 is installed on the target object 400. When the underwater camera 104 captures an image containing the positioning marker 105, the host computer 101 identifies and locates the positioning marker 105 in the image, and obtains the horizontal relative position between the lifting robot and the target object 400 based on the identification and positioning result.

[0079] In one embodiment of the present invention, the positioning unit includes an ultra-short baseline positioning module and a visual positioning module, and other positioning methods can be selected during specific implementation. Among them, the ultra-short baseline positioning method performed by the ultra-short baseline positioning module is consistent with the prior art, and the ultra-short baseline transducer 1031 receives the signal sent by the ultra-short baseline beacon 1032, and measures the relative position of the ultra-short baseline beacon 1032 and the ultra-short baseline transducer 1031, that is, the relative position between the lifting robot 300 and the mother boat 200 is measured, thereby obtaining the horizontal relative position between the lifting robot 300 and the mother boat 200.

[0080] Before visual positioning, the positioning marker 105 is pre-installed on the target object 400. In the marine environment, the positioning marker 105 needs to be easy to collect and identify. Preferably, the positioning marker 105 is a QR code mark plate. The host computer 101 records the mass m of the target object 400. t , and the relative position between the positioning marker 105 and the docking lifting point of the target object 400. When performing visual positioning, the underwater camera 104 collects video image information containing the positioning marker 105, and automatically identifies the positioning marker 105 using existing video image processing technology, converts the image coordinates of the positioning marker 105 into two-dimensional coordinates of the horizontal relative position between the positioning marker 105 and the lifting robot 300, and obtains the horizontal relative position between the lifting robot 300 and the docking lifting point of the target object 400 based on the three-dimensional coordinates of the relative position between the positioning marker 105 and the docking lifting point of the target object 400.

[0081] Furthermore, the mother boat 200 is also provided with a current meter 102 for obtaining ocean current information, and a current meter 103 for obtaining the hovering depth d of the mother boat 200. u When calculating the preset hovering position, the parameters configured by the host computer 101 include the hovering depth d of the mother boat 200. u , the three-dimensional coordinates (x t ,y t , d t ), target object 400 mass m tAs well as the relative position between the positioning marker 105 and the docking lifting point of the target object 400, in one embodiment of the present invention, the three-dimensional coordinates used for calculation are three-dimensional coordinates generated in a geodetic coordinate system, wherein the geodetic coordinate system takes the intersection of the earth's longitude 0° and latitude 0° on the sea level as the origin, and the directions corresponding to the three-dimensional coordinate axes x-axis, y-axis, and z-axis are as follows: Figure 1 shown.

[0082] The host computer 101 sets the laying cable length of the winch 202 after the target object 400 is docked to L i , and based on the hovering depth d of the mother ship 200 u 、Target object 400 mass m t As well as parameters such as ocean current information, existing finite element methods such as the concentrated mass method are used to calculate the cable length L i The three-dimensional coordinates (δx i ,δy i ,δz i ), for the cable length L i Calculate, then:

[0083]

[0084] Where η is the iterative calculation convergence parameter and 0≤η≤1, i is the number of iterations, L i-1 is the cable length calculated for the i-1th time, δz i-1 The cable length is L i-1 The z-axis coordinate value of the three-dimensional coordinates of the relative position of the lifting robot 300 and the mother boat 200;

[0085] Calculate the cable length as L i The relative distance h between the lifting robot 300 and the target object 400 in the z-axis direction is i , then:

[0086] h i =|d t -d u -δz i |

[0087] If h i Less than the set threshold h dead , then based on the cable length L i The relative position of the lifting robot 300 and the mother boat 200 is used to obtain the three-dimensional coordinates (x i ,y i , z i ), then:

[0088]

[0089] Set the threshold h dead is the threshold value of the distance between the lifting robot 300 and the target object 400 in the z-axis direction, and the threshold value h is set dead =L r , in specific implementation, set the threshold h dead The selection can be made according to actual needs, and the specific calculation shall be based on the calculation that can meet the preset hovering position of the mother boat 200.

[0090] Further, when the first placement point is confirmed, the two-dimensional coordinates (x e ,y e ), and determine the horizontal relative distance d between the lifting robot 300 and the target object 400;

[0091] If the horizontal relative distance d is greater than the movement radius R of the lifting robot 300, the host computer 101 controls the mother boat 200 to move to the calibration hovering position, and the lifting robot 300 moves with the mother boat 200, and the position of the lifting robot 300 after moving is used as the first deployment landing point.

[0092] Specifically, the three-dimensional relative position coordinates between the first deployment point of the lifting robot 300 and the mother boat 200 are obtained by the ultra-short baseline positioning method. Based on the three-dimensional position coordinates of the preset hovering position of the mother boat, the three-dimensional position coordinates of the lifting robot 300 in the earth coordinate system are converted to (x a ,y a , z a ), calculate the two-dimensional coordinates (x e ,y e ), then:

[0093]

[0094] Based on the two-dimensional coordinates (x e ,y e ), calculate the horizontal relative distance d between the lifting robot 300 and the target object 400, then:

[0095]

[0096] Determine the relationship between the horizontal relative distance d and the movement radius R of the lifting robot 300. If d≤R, the position of the lifting robot 300 is used as the first placement point after confirmation.

[0097] If d>R, the host computer 101 controls the mother boat to move to the calibration hovering position through the underwater mother boat navigation control subsystem 201, and the lifting robot 300 moves with the mother boat 200. After the position of the lifting robot 300 remains unchanged, the position of the lifting robot 300 is used as the first placement point after confirmation, wherein the three-dimensional coordinates (x q ,y q , z q ) can be expressed as:

[0098]

[0099] Further, after confirming the first deployment point, the host computer 101 automatically performs the second stage of docking operations, controlling the winch 202 to continue to release the cable to deploy the lifting robot 300 until the height h of the lifting robot 300 from the seabed is less than the second height setting value h set2 , and confirm the second placement point. When the second placement point is confirmed, the target object 400 is coarsely aligned and finely aligned in sequence, wherein:

[0100] When the target object 400 is roughly aligned, the host computer 101 obtains the horizontal relative position of the lifting robot 300 and the mother boat 200 through ultra-short baseline positioning, and obtains the horizontal relative position deviation of the lifting robot 300 and the target object 400 based on the horizontal relative position of the lifting robot 300 and the mother boat 200 and the position information of the target object 400;

[0101] Based on the horizontal relative position deviation between the lifting robot 300 and the target object 400, the host computer 101 moves the lifting robot 300 through fixed-point control until the horizontal relative position deviation between the lifting robot 300 and the target object 400 matches the first deviation threshold s1;

[0102] Specifically, when the target object 400 is roughly aligned, the three-dimensional relative position coordinates between the position of the lifting robot 300 and the mother boat 200 are obtained in real time through the ultra-short baseline positioning method. The three-dimensional relative position coordinates include the horizontal relative position coordinates between the lifting robot 300 and the mother boat 200. Based on the three-dimensional position coordinates of the mother boat at this time, the three-dimensional position coordinates of the lifting robot 300 in the earth coordinate system are converted to (x b ,y b , z b ), calculate the two-dimensional coordinates (x e1 ,y e1 ), then:

[0103]

[0104] At this time, the horizontal relative distance d1 between the lifting robot 300 and the target object 400 is the value of the horizontal relative position deviation, wherein the horizontal relative distance d1 can be expressed as:

[0105]

[0106] The host computer 101 moves the lifting robot 300 through fixed-point control and calculates the horizontal relative distance d1 in real time until the horizontal relative position deviation between the lifting robot 300 and the target object 400 matches the first deviation threshold s1, where the match is that the value d1 of the horizontal relative position deviation satisfies 0≤d1<s1. In one embodiment of the present invention, the first deviation threshold s1=0.5l r , l r It is the diameter of the docking tool or the diameter of the motion range. In specific implementation, the first deviation threshold s1 can be selected according to actual needs, specifically based on whether it can meet the rough alignment of the target object 400.

[0107] After the rough alignment, due to the low accuracy of ultra-short baseline positioning and the presence of positioning errors, the lifting robot 300 is generally not located exactly above the target object 400. In order to improve the alignment accuracy, the target object 400 needs to be finely aligned.

[0108] Furthermore, when the target object 400 is precisely aligned, the lifting robot 300 is deployed until the upper computer 101 obtains the horizontal relative position deviation between the lifting robot 300 and the target object 400 through visual positioning;

[0109] Based on the horizontal relative position deviation between the lifting robot 300 and the target object 400, the upper computer 101 moves the lifting robot 300 through fixed-point control until the horizontal relative position deviation between the lifting robot 300 and the target object 400 matches the second deviation threshold s2, and uses the position of the lifting robot 300 at this time as the second placement point.

[0110] Specifically, due to factors such as the complex underwater environment and poor visibility, when the lifting robot 300 is located at the first deployment point, the distance between the underwater camera 104 and the target object 400 may not meet the requirement of collecting a clear image of the positioning marker 105. Therefore, when the target object 400 is precisely aligned, in order to ensure that the underwater camera 104 can collect a clear image of the positioning marker 105, it is necessary to deploy the lifting robot 300 by using the winch 202 to reduce the distance between the underwater camera 104 and the target object 400 until the upper computer 101 obtains the two-dimensional coordinates (x ) of the horizontal relative position between the lifting robot 300 and the target object 400 through the above-mentioned visual positioning method. o ,y o ).

[0111] At this time, the horizontal relative distance d2 between the lifting robot 300 and the target object 400 is the value of the horizontal relative position deviation in the fine calibration, wherein the horizontal relative distance d2 can be expressed as:

[0112]

[0113] The upper computer 101 moves the lifting robot 300 through fixed-point control and calculates the horizontal relative distance d2 in real time until the horizontal relative position deviation between the lifting robot 300 and the target object 400 matches the second deviation threshold s2, and uses the position of the lifting robot 300 as the second placement point. At this time, the lifting robot 300 is aligned with the target object 400.

[0114] The matching is that the value d2 of the horizontal relative position deviation in the fine calibration satisfies 0≤d2<s2. In one embodiment of the present invention, the first deviation threshold s2=0.1l r In specific implementation, the second deviation threshold s2 can be selected according to actual needs, specifically based on whether it can meet the precise alignment of the target object 400.

[0115] Further, in the fine alignment and the rough alignment, the horizontal relative position deviation between the lifting robot 300 and the target object 400 includes a position deviation in the direction of the first axis and a position deviation in the direction of the second axis, wherein the first axis is perpendicular to the second axis;

[0116] The fixed-point control includes calculating the expected thrust in the first-axis direction of the lifting robot 300 based on the position deviation between the lifting robot 300 and the target object 400 in the first-axis direction, and calculating the expected thrust in the second-axis direction of the lifting robot 300 based on the position deviation between the lifting robot 300 and the target object 400 in the second-axis direction. The upper computer controls the movement of the lifting robot 300 based on the expected thrust in the first-axis direction of the lifting robot 300 and the expected thrust in the second-axis direction of the lifting robot 300.

[0117] In one embodiment of the present invention, Figure 1 As shown, the first axis direction of the horizontal relative position deviation is the x-axis direction, and the second axis direction is the y-axis direction. Optionally, when the first axis direction is the y-axis direction, the second axis direction is the x-axis direction.

[0118] Before the lifting robot 300 works, the numerical relationship between the movement distance of the lifting robot 300 and the required thrust is obtained in advance according to the mass, volume and other parameters of the lifting robot 300. When performing fixed-point control, based on the position deviation between the lifting robot 300 and the target object 400 in the x-axis direction and the y-axis direction, the desired thrust in the x-axis direction and the y-axis direction are adjusted and controlled in the host computer 101, wherein the PID (Proportional Integral Derivative) control method or other adjustment control forms can be used during the adjustment control, which shall be based on the actual control requirements.

[0119] Specifically, the position deviation in the x-axis direction is the x-axis coordinate value of the two-dimensional coordinate of the horizontal relative position between the lifting robot 300 and the target object 400; the position deviation in the y-axis direction is the y-axis coordinate value of the two-dimensional coordinate of the horizontal relative position between the lifting robot 300 and the target object 400. The expected thrust in the x-axis direction is the thrust required when the lifting robot 300 moves in the x-axis direction of the target object 400 and the distance moved is equal to the position deviation in the x-axis direction; the expected thrust in the y-axis direction is the thrust required when the lifting robot 300 moves in the y-axis direction of the target object 400 and the distance moved is equal to the position deviation in the y-axis direction.

[0120] Taking the PID regulation control method as an example, when performing fixed-point control, the upper computer 101 obtains the position deviation in the x-axis direction and the y-axis direction in real time and uses it as the input value of the PID algorithm. Based on the numerical relationship between the movement distance of the lifting robot 300 and the required thrust, the PID algorithm is used to output the expected thrust in the x-axis direction and the y-axis direction to the lifting robot control subsystem 301 in real time; based on the expected thrust in the x-axis direction and the y-axis direction, the lifting robot control subsystem 301 controls the lifting robot 300 to move until the horizontal relative position deviation of the lifting robot 300 is less than the first deviation threshold s1 or the second deviation threshold s2.

[0121] Furthermore, before docking and lifting, the host computer 101 obtains the maximum cable release speed v of the winch 202. max , and controlling the cable release speed of the winch 202 in the first docking stage, the second docking stage, and the third docking stage, wherein,

[0122] In the first docking stage, the winch 202 is operated at the highest cable release speed v max Cable laying;

[0123] In the second docking stage, the winch 202 releases the cable at a speed of v1 before confirming the second deployment point, and releases the cable at a speed of v2 when confirming the second deployment point;

[0124] In the third docking stage, the winch 202 releases the cable at a speed v2, wherein:

[0125] Speed ​​v1 = k1v max , speed v2=k2v max , k1 is the first speed coefficient, k2 is the second speed coefficient, and k2≤k1≤1.

[0126] In one embodiment of the present invention, the first speed coefficient k1=0.3, the second speed coefficient k2=0.05. Optionally, the first speed coefficient k1 and the second speed coefficient k2 can be set according to actual needs, specifically based on the standard of being able to complete the safe deployment of the lifting robot 300.

[0127] The mother boat 200 is equipped with a balancing module, which adjusts the buoyancy of the mother boat 200 by controlling drainage and water injection. The working mode of the balancing module is consistent with the prior art. After the lifting robot 300 docks with the target object 400, the balancing module controls the mother boat 200 to be in a drainage state, and the displacement is the mass m of the target object 400. t After the drainage is completed, the target object 400 is lifted and recovered.

[0128] Furthermore, when recovering the target object 400, the host computer 101 controls the winch 202 to reel in the cable at a speed v3 until the height of the lifting robot 300 from the seabed is greater than the length L of the lifting robot 300 itself. r After that, the host computer 101 increases the cable retracting speed of the winch 202 to the maximum cable releasing speed v max ;

[0129] The distance between the lifting robot 300 and the mother boat 200 is less than the first safety distance L r1 After that, the host computer 101 reduces the cable retracting speed of the winch 202 to speed v4, where L r1 =m1L r , m1 is the first safety distance coefficient;

[0130] The distance between the lifting robot 300 and the mother boat 200 is less than the second safety distance L r2 After that, the host computer 101 reduces the retrieving speed of the winch 202 to speed v3, and stops retrieving when the cable length is less than the cable length safety setting value, completing the lifting and recovery of the target object 400, wherein L r2 =m2L r , m2 is the second safety distance coefficient.

[0131] Preferably, speed v3=v2, speed v4=v1. In specific implementation, on the basis of v3≤v4, speed v3 and speed v4 can be selected as needed to meet the standard of safe lifting and recovery of target object 400. In one embodiment of the present invention, the first safety distance coefficient m1=5, the second safety distance coefficient m2=2, and the safety setting value of the cable length is 0.5m. In specific implementation, the first safety distance coefficient m1 and the second safety distance coefficient m2 can be combined with the self length L of the lifting robot 300. r , set according to actual needs; the safety setting value of the cable length can also be set according to the actual winch model 202 and the total length of the cable 2022.

[0132] In order to realize the above-mentioned intelligent control method for underwater dual-platform docking and lifting operations, the present invention proposes an intelligent control system for underwater dual-platform docking and lifting operations, including an underwater dual platform and a host computer 101 for controlling the collaborative operation of the underwater dual platform, the underwater dual platform includes a mother boat 200 and a lifting robot 300 for docking and lifting a target object 400.

[0133] In one embodiment of the present invention, the host computer 101 is installed on a mother boat 200 carrying a lifting robot 300 and a winch 202, and the host computer is connected to a current meter 102, an ultra-short baseline transducer 1031, an ultra-short baseline beacon 1032, and an underwater camera 104 through a bus or a network. Based on the above intelligent control method, the host computer 101 controls the state of the mother boat 200 and the lifting robot 300 to control the lifting robot 300 to dock with the target object 400, and lift and recover the target object 400.

[0134] In summary, the present invention provides an intelligent control method and system for underwater dual-platform docking and lifting operations. When the system docks with a target object 400, the host computer 101 controls the mother boat 200 to be in a preset hovering position and deploys the lifting robot 300. In the process of deploying the lifting robot 300, the target object 400 is first roughly aligned based on ultra-short baseline positioning, and then the target object 400 is precisely aligned based on visual positioning, so that the lifting robot 300 is aligned with the target object 400, and docks and lifts the target object 400, without the need for artificial estimation based on the current environment, relative position and other information, thereby realizing automatic control of the entire process of docking and lifting the target object 400, improving the accuracy of the alignment of the target object 400, and having a high degree of intelligence. In addition, the above control system automatically realizes the switching from rough alignment to precise alignment, and the operator only needs to input the configuration parameters, without the need for additional manual operation, which effectively reduces the control load, improves the applicability of the control system, and realizes efficient and high-precision docking control of the target object 400.

[0135] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. An intelligent control method for underwater dual-platform docking and lifting operations, characterized in that: An underwater double platform and a host computer for controlling the underwater double platform are provided, wherein the underwater double platform includes a mother boat and a lifting robot for docking and lifting a target object, wherein: The mother boat carries a winch and a lifting robot, the lifting robot is connected to the winch through a cable, and the host computer controls the winch to release and retract the cable to deploy and lift and recover the lifting robot; Based on the position information of the mother boat and the position information of the target object, the host computer configures the preset hovering position of the mother boat, so that when the mother boat is in the preset hovering position, the placement point of the lifting robot under the action of the ocean current corresponds to the target object; When docking with a target object, the mother boat is in a preset hovering position and deploys the lifting robot. During the deployment of the lifting robot, the position state of the lifting robot is adjusted based on the horizontal relative position between the lifting robot and the target object until the lifting robot is aligned with the target object and docks with the target object. After the lifting robot docks with the target object, the host computer lifts and recovers the lifting robot and the target object; The position information of the mother boat at least includes the hovering depth d of the mother boat. u The position information of the target object at least includes the three-dimensional coordinates (x t ,y t , d t ); When configuring the preset hovering position, the host computer sets the length of the winch cable after docking with the target object to be L i , and the cable length is L i The three-dimensional coordinates of the relative position between the lifting robot and the mother ship (δx i ,δy i ,δz i ), for the cable length L i Calculate, then: Where η is the iterative calculation convergence parameter and 0≤η≤1, i is the number of iterations, L i-1 is the cable length calculated for the i-1th time, δz i-1 The cable length is L i-1 The z-axis coordinate value of the three-dimensional coordinates of the relative position of the lifting robot and the mother boat; Calculate the cable length as L i The relative distance h between the lifting robot and the target object in the z-axis direction i , then: h i =|d t -d u -δz i | If h i Less than the set threshold h dead , then based on the cable length L i The relative position of the lifting robot and the mother boat is used to obtain the three-dimensional coordinates (x i ,y i , z i ), then:

2. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 1 is characterized in that: When docking with a target object, it includes the first docking stage, the second docking stage and the third docking stage, in which: During the first stage of docking, the host computer controls the mother ship to move to the preset hovering position and deploys the lifting robot, and confirms the first deployment point based on the horizontal relative position between the lifting robot and the target object, so that the horizontal relative distance between the first deployment point of the lifting robot and the target object is less than or equal to the movement radius R of the lifting robot; During the second stage of docking, the host computer deploys the lifting robot and determines the second deployment point based on the horizontal relative position between the lifting robot and the target object, so that the second deployment point of the lifting robot is located directly above the target object; During the third docking phase, the host computer deploys the lifting robot so that the lifting robot docks with the target object.

3. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 2 is characterized in that: It also includes a positioning unit for positioning during docking, wherein: The positioning unit includes an ultra-short baseline positioning module and a visual positioning module, wherein: The ultra-short baseline positioning module performs ultra-short baseline positioning on the lifting robot to obtain the horizontal relative position between the lifting robot and the mother boat; The ultra-short baseline positioning module includes an ultra-short baseline transducer and an ultra-short baseline beacon, wherein the ultra-short baseline transducer is installed on the mother boat, and the ultra-short baseline beacon is installed on the lifting robot; The visual positioning module performs visual positioning on the target object, and includes an underwater camera and a positioning marker. The underwater camera is installed on the lifting robot, and the positioning marker is installed on the target object. When the underwater camera captures an image containing the positioning marker, the host computer identifies and locates the positioning marker in the image, and obtains the horizontal relative position between the lifting robot and the target object based on the identification and positioning result.

4. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 1 is characterized in that: When the first placement point is confirmed, obtain the two-dimensional coordinates (x e ,y e ), and determine the horizontal relative distance d between the lifting robot and the target object; If the horizontal relative distance d is greater than the motion radius R of the lifting robot, the host computer controls the mother boat to move to the calibration hovering position, and the lifting robot moves with the mother boat, and the position of the lifting robot after moving is used as the first placement point, where the three-dimensional coordinates (x q ,y q , z q ) can be expressed as:

5. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 3 is characterized in that: When the second placement point is confirmed, the target object is coarsely aligned and finely aligned in sequence, wherein: When the target object is roughly aligned, the host computer obtains the horizontal relative position of the lifting robot and the mother ship through ultra-short baseline positioning, and obtains the horizontal relative position deviation of the lifting robot and the target object based on the horizontal relative position of the lifting robot and the mother ship and the position information of the target object; Based on the horizontal relative position deviation between the lifting robot and the target object, the host computer moves the lifting robot through fixed-point control until the horizontal relative position deviation between the lifting robot and the target object matches the first deviation threshold s1; When the target object is precisely aligned, the lifting robot is deployed until the upper computer obtains the horizontal relative position deviation between the lifting robot and the target object through visual positioning; Based on the horizontal relative position deviation between the lifting robot and the target object, the upper computer moves the lifting robot through fixed-point control until the horizontal relative position deviation between the lifting robot and the target object matches the second deviation threshold s2, and uses the position of the lifting robot at this time as the second placement point.

6. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 5 is characterized in that: The horizontal relative position deviation between the lifting robot and the target object includes a position deviation in a first axis direction and a position deviation in a second axis direction, wherein the first axis is perpendicular to the second axis; The fixed-point control includes calculating the expected thrust in the first-axis direction of the lifting robot based on the position deviation between the lifting robot and the target object in the first-axis direction, and calculating the expected thrust in the second-axis direction of the lifting robot based on the position deviation between the lifting robot and the target object in the second-axis direction. The upper computer controls the movement of the lifting robot based on the expected thrust in the first-axis direction of the lifting robot and the expected thrust in the second-axis direction of the lifting robot.

7. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 2 is characterized in that: The host computer obtains the maximum cable release speed v of the winch max , and control the cable release speed of the winch in the first docking stage, the second docking stage and the third docking stage, wherein, In the first stage of docking, the winch is operated at the maximum cable release speed v max Cable laying; In the second stage of docking, the winch releases the cable at speed v1 before confirming the second deployment point, and releases the cable at speed v2 when confirming the second deployment point; In the third docking phase, the winch releases the cable at a speed v2, where Speed ​​v1 = k1v max , speed v2=k2v max , k1 is the first speed coefficient, k2 is the second speed coefficient, and k2≤k1≤1.

8. The intelligent control method for underwater dual-platform docking and lifting operations according to claim 7 is characterized in that: When recovering the target object, the host computer controls the winch to reel in the cable at a speed of v3 until the height of the lifting robot from the seabed is greater than the length of the lifting robot itself, L r After that, the host computer increases the winch's cable-receiving speed to the maximum cable-releasing speed v max ; The distance between the lifting robot and the mother ship is less than the first safety distance L r1 After that, the host computer reduces the winch's cable-receiving speed to speed v4, where L r1 =m1L r , m1 is the first safety distance coefficient; The distance between the lifting robot and the mother ship is less than the second safety distance L r2 After that, the host computer reduces the winch's retracting speed to speed v3, and stops retracting when the cable length is less than the cable length safety setting value, completing the lifting and recovery of the target object. r2 =m2L r , m2 is the second safety distance coefficient.

9. An intelligent control system for underwater dual-platform docking and lifting operations, characterized in that: It includes an underwater dual platform and a host computer for controlling the collaborative operation of the underwater dual platform, wherein the underwater dual platform includes a mother boat and a lifting robot for docking and lifting a target object, wherein: The host computer is installed on a mother boat equipped with a lifting robot and a winch. Based on the intelligent control method described in any one of claims 1 to 8, the host computer controls the status of the mother boat and the lifting robot to control the lifting robot to dock with the target object and lift and recover the target object.

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