Ocean platform in-place distance measurement method and system

Abstract

The invention discloses an ocean platform in-place distance measurement method and system, and the method comprises the steps: obtaining first distance data collected by a first distance measurement device and second distance data collected by a second distance measurement device, and enabling the first distance measurement device and the second distance measurement device to be disposed on the side surface, close to a tested platform, of a test platform, and matching the positions corresponding to the same points on the tested platform in the first distance data and the second distance data, and obtaining the pose of the tested platform relative to the test platform according to the distance and orientation of at least two points on the tested platform relative to the first distance measuring device and the distance and orientation of at least two points on the tested platform relative to the second distance measuring device. Therefore, the tested platform is controlled to be in place. The pose of the tested platform relative to the test platform is obtained according to the distance and orientation of the point on the tested platform relative to the first distance measuring device and the second distance measuring device, the measurement accuracy of the relative pose between the two platforms in the ocean platform in-place process can be improved, the working efficiency is improved, and accidents are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of marine oil and gas development equipment, and in particular to an on-site distance measurement method and system for a marine platform. Background Art

[0002] In the development of offshore oil and gas, offshore platforms play an important role. When the operation of a well is completed, the platform needs to be moved to the next well by multiple towing ships for construction work, and the next well needs to be positioned when it arrives.

[0003] The patent with publication number CN210827404U discloses an offshore drilling platform positioning assistance system, including a displacement sensor, a waterproof camera, a PLC main control module and a touch display screen; the displacement sensor is set in two groups, which are respectively installed on the front and rear end faces of the drilling platform, and each group of displacement sensors has two, and they are respectively located on both sides of the same end face of the drilling platform; there are more than four waterproof cameras, which are respectively installed on each side of the drilling platform; the PLC main control module is installed in the main control room of the drilling platform, and is used to receive signals from various sensors and cameras, and convert the signal processing into dynamic digital signals and video images for intuitive display on the touch display screen. The auxiliary system can enable the personnel on the drilling platform and the towing ship to more intuitively understand the situation around and below the drilling platform.

[0004] However, this technology has the following disadvantages: this technical solution only achieves the purpose of discovering obstacles and roughly measuring the distance to the obstacles, and cannot achieve accurate ranging, resulting in low reliability and accuracy during the positioning of the auxiliary platform. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for measuring distance during the positioning of an offshore platform, which can improve the measurement accuracy of the relative posture between two platforms during the positioning of the offshore platform, provide technical support for the positioning operation of the offshore platform, improve work efficiency, and reduce accidents.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for measuring distance on an ocean platform in situ, comprising:

[0008] Acquire first distance data collected by a first distance measuring device and second distance data collected by a second distance measuring device, wherein the first distance measuring device and the second distance measuring device are respectively arranged on a side of the test platform close to the platform under test, the first distance data includes the distance and orientation of each point within a preset range on the platform under test relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the platform under test relative to the second distance measuring device;

[0009] According to the relative positions of the first distance measuring device and the second distance measuring device, matching the positions of the first distance data and the second distance data corresponding to the same point on the measured platform;

[0010] The position of the measured platform relative to the test platform is obtained according to the distance and orientation of at least two points on the measured platform relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device, so as to control the measured platform in place.

[0011] Optionally, on a side of the test platform close to the platform under test, a plurality of distance measuring devices are arranged in sequence from far to near around the central axis of the side, and two of the plurality of distance measuring devices are respectively used as the first distance measuring device and the second distance measuring device.

[0012] Optionally, obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises:

[0013] Selecting a first point and a second point on the platform under test, and calculating the inclination angle of the platform under test relative to the test platform based on a triangle formed by any three of the first point, the second point, the first distance measuring device, and the second distance measuring device, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first distance measuring device and the second distance measuring device are located is taken as the inclination angle of the platform under test relative to the test platform;

[0014] The distances and orientations of the first point and the second point relative to the first distance measuring device are obtained according to the first distance data, and the distances and orientations of the first point and the second point relative to the second distance measuring device are obtained according to the second distance data.

[0015] Optionally, obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises:

[0016] Selecting a first point, a second point, and a second midpoint on the platform under test, and calculating the midpoint distance between the platform under test and the test platform based on a triangle formed by any three of the first point, the second point, the second midpoint, the first distance measuring device, the second distance measuring device, and the first midpoint;

[0017] The second midpoint is the midpoint of the platform under test, and the position of the first point relative to the second midpoint and the position of the second point relative to the first midpoint are both determined, the first midpoint is the midpoint of the test platform, and the position of the first distance measuring device relative to the first midpoint and the position of the second distance measuring device relative to the first midpoint are both determined;

[0018] Among them, the distances and orientations of the first point, the second point, and the second midpoint relative to the first ranging device are obtained respectively according to the first distance data, and the distances and orientations of the first point, the second point, and the second midpoint relative to the second ranging device are obtained respectively according to the second distance data.

[0019] Optionally, obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises:

[0020] Selecting a first point and a second point on the platform under test, and calculating the shortest distance between the platform under test and the test platform based on a triangle formed by any three of the first point, the second point, the first projection point, the first distance measuring device, the second distance measuring device, and a preset edge point of the test platform;

[0021] The first projection point is the projection point of the first distance measuring device or the second distance measuring device on the platform under test, the preset edge point is the edge point of the test platform closer to the platform under test, the second projection point is the projection point of the preset edge point on the platform under test, and the distance between the second projection point and the preset edge point is the shortest distance;

[0022] The distances and orientations of the first point and the second point relative to the first distance measuring device are obtained according to the first distance data, and the distances and orientations of the first point and the second point relative to the second distance measuring device are obtained according to the second distance data.

[0023] Optionally, obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises:

[0024] Based on the triangle formed by any three of the first point, the second point, the first distance measuring device, and the second distance measuring device, the inclination angle of the platform under test relative to the test platform is calculated, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first distance measuring device and the second distance measuring device are located is taken as the inclination angle of the platform under test relative to the test platform;

[0025] The shortest distance is obtained according to the distance between the first projection point and the distance measuring device corresponding to the first projection point, and the tilt angle.

[0026] Optionally, it also includes:

[0027] Acquire images of the platform under test captured by at least two camera devices, wherein the at least two camera devices are disposed on a side of the test platform close to the platform under test;

[0028] According to the images captured by the at least two cameras, depth information of the platform under test is obtained to construct a three-dimensional image of the platform under test, and the obtained data describing the posture of the platform under test relative to the test platform is fused with the three-dimensional image of the platform under test.

[0029] Optionally, it also includes:

[0030] Perform feature point matching on the two frames of images captured by the camera device.

[0031] The rotation information and translation information of the measured platform movement are obtained according to the matched feature points in the two preceding and succeeding frames of the image, and the movement model of the measured platform is established based on the three-dimensional image of the measured platform.

[0032] An in-situ distance measurement system for an ocean platform, comprising:

[0033] The first distance measuring device and the second distance measuring device are respectively arranged on the side of the test platform close to the platform under test, and are used to collect and obtain first distance data and second distance data respectively, wherein the first distance data includes the distance and orientation of each point within a preset range on the platform under test relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the platform under test relative to the second distance measuring device;

[0034] The comprehensive processing device is communicatively connected with the first distance measuring device and the second distance measuring device respectively, and is used to obtain the posture of the measured platform relative to the test platform according to the distance and orientation of at least two points on the measured platform relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device, and according to the relative positions of the first distance measuring device and the second distance measuring device, so as to control the measured platform to be in place.

[0035] Optionally, it also includes:

[0036] At least two camera devices, respectively arranged on the side of the test platform close to the platform under test, and the camera devices are used to capture images of the platform under test;

[0037] The comprehensive processing device is further used to obtain the depth information of the platform under test to construct a three-dimensional image of the platform under test based on the images captured by the at least two camera devices, and fuse the obtained data describing the position and posture of the platform under test relative to the test platform with the three-dimensional image of the platform under test;

[0038] The comprehensive processing device runs the following threads: a first thread for acquiring the image captured by the camera device; a second thread for acquiring the first distance data captured by the first distance measuring device; a third thread for acquiring the second distance data captured by the second distance measuring device; a fourth thread for copying the distance data acquired by the second thread and the third thread based on the image acquired by the first thread, and fusing the image and the distance data; a fifth thread for copying the image acquired by the first thread, constructing a three-dimensional image of the platform under test based on the image, and copying the fusion result acquired by the fourth thread, and displaying the three-dimensional image and the fusion result.

[0039] It can be seen from the above technical scheme that the present invention provides a method and system for measuring distance on an offshore platform in position, the method comprising: obtaining first distance data collected by a first distance measuring device and second distance data collected by a second distance measuring device, the first distance measuring device and the second distance measuring device being respectively arranged on the side of the test platform close to the platform under test, the first distance data comprising the distance and azimuth of each point on the platform under test within a preset range relative to the first distance measuring device, and the second distance data comprising the distance and azimuth of each point on the platform under test within a preset range relative to the second distance measuring device; matching the positions corresponding to the same point on the platform under test in the first distance data and the second distance data according to the relative positions of the first distance measuring device and the second distance measuring device; further obtaining the posture of the platform under test relative to the test platform according to the distance and azimuth of at least two points on the platform under test relative to the first distance measuring device and the distance and azimuth relative to the second distance measuring device, so as to control the platform under test in position.

[0040] In the method and system for measuring distance in position of an ocean platform of the present invention, the first distance measuring device and the second distance measuring device respectively collect and obtain the distance and orientation of each point on the measured platform within a preset range relative to the distance measuring device, and the position and orientation of the measured platform relative to the test platform are obtained in combination with the distance and orientation of the point on the measured platform relative to the first distance measuring device and the second distance measuring device. Compared with the prior art, the measurement accuracy of the relative position and orientation between the two platforms during the process of positioning the ocean platform can be improved, technical support can be provided for the positioning operation of the ocean platform, work efficiency can be improved, and accidents can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A flow chart of an on-site distance measurement method for an offshore platform provided by an embodiment of the present invention;

[0043] Figure 2 It is a schematic diagram of arranging a distance measuring device and a camera device on a test platform in an in-situ distance measuring method for an offshore platform according to an embodiment of the present invention;

[0044] Figure 3 A top view of a test platform and a tested platform according to an embodiment of the present invention;

[0045] Figure 4 It is a simplified schematic diagram of obtaining the inclination angle of the measured platform relative to the test platform in the method for measuring the distance between the offshore platform in situ according to one embodiment of the present invention;

[0046] Figure 5 It is a simplified schematic diagram of obtaining the midpoint distance between the measured platform and the test platform in the method for measuring the distance between the offshore platform in situ according to one embodiment of the present invention;

[0047] Figure 6 It is a simplified schematic diagram of obtaining the shortest distance between the measured platform and the test platform in the method for measuring the distance between the offshore platform in situ according to one embodiment of the present invention;

[0048] Figure 7-1 A principle flow chart of thread 1 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0049] Figure 7-2 A principle flow chart of thread 2 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0050] Figure 7-3A principle flow chart of thread 3 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0051] Figure 8 An initialization flow chart of an offshore platform in-situ ranging system provided by an embodiment of the present invention;

[0052] Fig. 9 A principle flow chart of thread 4 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0053] Fig.10 A principle flow chart of thread 5 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0054] Fig.11 A principle flow chart of thread 6 of an offshore platform in-situ ranging system provided by one embodiment of the present invention;

[0055] Fig.12 A stop action flow chart of an offshore platform in-situ ranging system provided by one embodiment of the present invention.

[0056] The reference numerals in the drawings of the specification include:

[0057] 1-testing platform, 2-tested platform, 101-laser radar, 102-millimeter wave radar, 103-camera device, 104-junction box. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0059] For reference Figure 1 , Figure 1 This is a flow chart of a method for measuring distance on an offshore platform provided by an embodiment. As shown in the figure, the method for measuring distance on an offshore platform includes the following steps:

[0060] S11: Acquire first distance data collected by a first distance measuring device and second distance data collected by a second distance measuring device, wherein the first distance measuring device and the second distance measuring device are respectively arranged on a side of a test platform close to a platform to be tested.

[0061] The first distance data includes the distance and orientation of each point within a preset range on the measured platform relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the measured platform relative to the second distance measuring device.

[0062] The platform under test approaches the testing platform to put the platform under test in place, and a first distance measuring device and a second distance measuring device are arranged on the side of the testing platform close to the platform under test, and the relative positions of the first distance measuring device and the second distance measuring device are determined.

[0063] The preset range on the measured platform is within the field of view of the first ranging device, so that the first ranging device can collect and obtain the distance and azimuth of each point within the preset range on the measured platform relative to the first ranging device; and the preset range on the measured platform is also within the field of view of the second ranging device, so that the second ranging device can collect and obtain the distance and azimuth of each point within the preset range on the measured platform relative to the second ranging device.

[0064] S12: According to the relative positions of the first distance measuring device and the second distance measuring device, matching the positions of the first distance data and the second distance data corresponding to the same point on the measured platform.

[0065] For example, position A in the first distance data corresponds to point C of the platform under test, and position B in the second distance data corresponds to point C of the platform under test. Then position A in the first distance data is matched with position B in the second distance data, and both correspond to point C of the platform under test.

[0066] S13: Obtain the position of the measured platform relative to the test platform according to the distance and orientation of at least two points on the measured platform relative to the first ranging device and the distance and orientation relative to the second ranging device, so as to control the measured platform to be in place.

[0067] After matching the positions of the first distance data and the second distance data corresponding to the same point on the measured platform, for a point on the measured platform, the distance and orientation of the point relative to the first distance measuring device can be obtained based on the first distance data, and the distance and orientation of the point relative to the second distance measuring device can be obtained based on the second distance data.

[0068] The posture of the platform under test relative to the test platform includes the position or posture of the platform under test relative to the test platform, and may include the distance or angle of the platform under test relative to the test platform.

[0069] In the method for measuring distance during the placement of an ocean platform of the present embodiment, the first distance measuring device and the second distance measuring device are used to respectively collect the distance and orientation of each point on the measured platform within a preset range relative to the distance measuring device, and the position and orientation of the measured platform relative to the test platform are obtained in combination with the distance and orientation of the top point on the measured platform relative to the first distance measuring device and the second distance measuring device. Compared with the prior art, the measurement accuracy of the relative position and orientation between the two platforms during the placement of an ocean platform can be improved, thereby providing technical support for the placement of an ocean platform, improving work efficiency, and reducing the occurrence of accidents.

[0070] At least two distance measuring devices may be arranged on the side of the test platform close to the platform under test, and two of the at least two distance measuring devices are used as the first distance measuring device and the second distance measuring device, respectively. When selecting the first distance measuring device and the second distance measuring device from the at least two distance measuring devices, it is required that the first distance measuring device can collect and obtain the distance and azimuth data of each point within a preset range on the platform under test, and the second distance measuring device can also collect and obtain the distance and azimuth data of each point within the preset range on the platform under test. When the distance measuring devices are arranged on the test platform, it is ensured that for any distance between the test platform and the platform under test, at least two distance measuring devices can work effectively.

[0071] In this embodiment, the type and structure of the distance measuring device are not limited, as long as the collected distance data includes the distance and orientation of each point within a certain range on the measured platform relative to the distance measuring device. The distance measuring device can be, but is not limited to, a laser radar or a millimeter wave radar. Preferably, a laser radar and a millimeter wave radar can be arranged on the test platform at the same time. The laser radar has a long measurement distance, but is easily affected by the environment, such as ambient light or humidity, while the millimeter wave radar is relatively less affected by the environment and has a larger field of view, such as a field of view of up to 140 degrees.

[0072] In some embodiments, on the side of the test platform close to the platform under test, multiple distance measuring devices are arranged in sequence from far to near around the central axis of the side, and two of the multiple distance measuring devices are used as the first distance measuring device and the second distance measuring device respectively. Figure 2 , Figure 2 The present invention is a schematic diagram of arranging a ranging device and a camera device on a test platform in an on-site ranging method for an ocean platform in one embodiment. As shown in the figure, a laser radar 101 is arranged at the center of one side of the test platform 1, and a camera device 103, a laser radar 101 and a millimeter-wave radar 102 are arranged in sequence from far to near around the center, and are arranged symmetrically on both sides of the center.

[0073] A signal processor may be provided at the end of the laser radar 101 and the millimeter wave radar 102, and a signal processor may be provided at the end of the camera device 103. Figure 2As shown, the signal processor is arranged in the junction box 104, and the signal processor is used to analyze and process the data collected by the corresponding equipment, and then transmit the data to the comprehensive processing device. The signal processor can organize the basic data structure of the raw data collected by the corresponding equipment, output it in a unified coordinate and speed information format, and / or adjust the data according to the network transmission protocol to make it meet the unified data transmission requirements.

[0074] In this embodiment, the method for matching the positions of the first distance data and the second distance data corresponding to the same point on the platform 2 under test according to the relative positions of the first distance measuring device and the second distance measuring device is not limited. Optionally, in some embodiments, matching the positions of the first distance data and the second distance data corresponding to the same point on the platform 2 under test according to the relative positions of the first distance measuring device and the second distance measuring device includes: converting each point within the preset range on the platform 2 under test into a preset three-dimensional coordinate system according to the first distance data, and converting each point within the preset range on the platform 2 under test into the preset three-dimensional coordinate system according to the second distance data, and matching the positions of the first distance data and the second distance data corresponding to the same point on the platform 2 under test according to the positions of each point within the preset range on the platform 2 under test in the preset three-dimensional coordinate system. Among them, each point within the preset range on the platform 2 under test in the first distance data can be converted into a preset three-dimensional coordinate system according to the arrangement position of the first distance measuring device on the test platform 1, and each point within the preset range on the platform 2 under test in the second distance data can be converted into a preset three-dimensional coordinate system according to the arrangement position of the second distance measuring device on the test platform 1.

[0075] In some embodiments, obtaining the position and orientation of the platform 2 under test relative to the test platform 1 based on the distance and orientation of at least two points on the platform 2 under test relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device includes: selecting a first point and a second point on the platform 2 under test, and calculating the inclination angle of the platform 2 under test relative to the test platform 1 based on a triangle formed by any three of the first point, the second point, the first distance measuring device, and the second distance measuring device, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first distance measuring device and the second distance measuring device are located is used as the inclination angle of the platform 2 under test relative to the test platform 1; wherein the distance and orientation of the first point and the second point relative to the first distance measuring device are respectively obtained based on the first distance data, and the distance and orientation of the first point and the second point relative to the second distance measuring device are respectively obtained based on the second distance data. The first point and the second point are selected within a preset range on the platform 2 under test.

[0076] Optionally, the first point and the second point are in the same horizontal plane, and the first ranging device and the second ranging device can be projected onto the horizontal plane. On the horizontal plane, a straight line parallel to the straight line where the first point and the second point are located is drawn through the projection point of the second ranging device. According to the triangle formed by the first point, the projection point of the first ranging device, and the projection point of the second ranging device, and the triangle formed by the first point, the second point, and the projection point of the second ranging device, the angle between the straight line where the first point and the second point are located and the straight line where the projection point of the first ranging device and the projection point of the second ranging device are located is calculated as the inclination angle of the measured platform relative to the test platform.

[0077] Alternatively, if the first point and the second point are not in the same horizontal plane, the first point, the second point, the first ranging device, and the second ranging device can all be projected onto a horizontal plane. On this horizontal plane, the angle between the straight line where the projection point of the first point and the projection point of the second point are located and the straight line where the projection point of the first ranging device and the projection point of the second ranging device are located can be solved based on the triangle formed by any three of the projection points as the inclination angle of the measured platform relative to the test platform.

[0078] For example, reference may be made to Figure 3 , Figure 3 This is a top view of the test platform and the tested platform of an embodiment, specifically a top view of the ideal state when the test platform 1 and the tested platform 2 are docked. When encountering an emergency, the tested platform 2 on the right needs to be adjusted. Therefore, the right end of the left test platform 1 and the left end of the right tested platform 2 are taken to establish a model to simulate the distance and angle relationship between the two platforms. Among them, the test platform 1 is an oil production platform, and the tested platform 2 is a jack-up platform.

[0079] For reference Figure 4 , Figure 4 This is a simplified schematic diagram of obtaining the inclination angle of the measured platform relative to the test platform in the method for measuring the distance of an offshore platform in place according to an embodiment. As shown in the figure, one leg of the measured platform 2 is selected as point A and the other leg is selected as point B. The first distance measuring device and the second distance measuring device on the test platform 1 are selected as point C and point D respectively. The horizontal distances from the first distance measuring device to point A and point B are d respectively. 1 d 2 , the angle is θ 1 The horizontal distances from the second distance measuring device to point A and point B are d 3 d 4 , the angle is θ 2 The horizontal distance between the two pile legs is d 6 , the distance between the first distance measuring device and the second distance measuring device is d 5As shown in the figure, a line parallel to the straight line AB is drawn through point D, intersecting AC at point P. The angle θ in the figure is the inclination angle of the measured platform 2 relative to the test platform 1. According to the distance data collected by the first distance measuring device and the second distance measuring device, the following information can be obtained: θ 1 ,θ 2 d 1 d 2 d 3 d 4 .

[0080] According to the triangle formed by any three points A, B, C and D, first solve △ACD to find ∠ADC; then solve △ABD to find ∠DAB; according to the equality of interior alternate angles, ∠DAB = ∠ADP; therefore, the required angle θ = ∠ADC-∠ADP. The specific formula is as follows:

[0081] ⅰFind ∠ADC (denoted by α below)

[0082]

[0083] ⅱFind ∠DAB (hereinafter represented by β)

[0084] To find ∠DAB, first find the distance AB between the pile legs, that is, d 6 :

[0085]

[0086]

[0087] ⅲCalculate the tilt angle θ:

[0088]

[0089] In order to ensure that the imaging equipment of the jack-up platform can accurately reflect the position of the oil production platform, it is necessary to ensure that the relative position between the two platforms is as accurate as possible. Therefore, it is necessary to select the midpoint of the two platforms as an indicator for safety distance consideration. Correspondingly, in some embodiments, obtaining the position and orientation of the measured platform 2 relative to the test platform 1 according to the distance and orientation of at least two points on the measured platform 2 relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device includes: selecting a first point, a second point and a second midpoint on the measured platform 2, and calculating the midpoint distance between the measured platform 2 and the test platform 1 based on a triangle formed by any three of the first point, the second point, the second midpoint, the first distance measuring device, the second distance measuring device and the first midpoint; wherein the second midpoint is the midpoint of the measured platform 2, and the position of the first point relative to the second midpoint and the position of the second point relative to the first midpoint are both determined, the first midpoint is the midpoint of the test platform 1, and the position of the first distance measuring device relative to the first midpoint and the position of the second distance measuring device relative to the first midpoint are both determined; wherein the distances and orientations of the first point, the second point and the second midpoint relative to the first distance measuring device are respectively obtained according to the first distance data, and the distances and orientations of the first point, the second point and the second midpoint relative to the second distance measuring device are respectively obtained according to the second distance data.

[0090] A first point, a second point, and a second midpoint are selected within a preset range on the measured platform 2, that is, the first point, the second point, and the second midpoint are all within the field of view of the first distance measuring device and within the field of view of the second distance measuring device. Optionally, when selecting the first point and the second point, the second midpoint can be the midpoint of the first point and the second point, which is convenient for calculation.

[0091] Optionally, the distance between the second midpoint and the first midpoint, i.e. the midpoint distance between the platform 2 to be tested and the test platform 1, can be calculated based on the triangle formed by the first point, the second midpoint and the second distance measuring device, the triangle formed by the first point, the second distance measuring device and the first distance measuring device, and the triangle formed by the second midpoint, the second distance measuring device and the first midpoint. Figure 5 , Figure 5 This is a simplified schematic diagram of obtaining the midpoint distance between the measured platform and the test platform in the method for measuring the distance between the measured platform in position according to an embodiment. As shown in the figure, the midpoint of the test platform 1 is point E, the midpoint of the measured platform 2 is point F, and the line segment EF represents the desired midpoint distance between the measured platform 2 and the test platform 1. The distance between the second distance measuring device point D and the first midpoint E is d 7. According to the triangle formed by any three of points A, B, C, D, E, and F, first solve △AFD to find cos∠DAB; then solve △ABD to find FD; to find ∠FDE, find ∠ADF and ∠ADE in turn; finally, the required side EF can be found through ∠FED. The specific formula is as follows:

[0092] ⅰ Find cos∠DAB

[0093] BD 2 =AB 2 +AD 2 -2AD·ABcos∠DAB,d 4 2 =d 6 2 +d 3 2 -2d 6 ·d 3 cos∠DAB;

[0094]

[0095] ⅱRequest FD

[0096]

[0097] ∴

[0098] ⅲ Find ∠ADF

[0099] AF 2 =FD 2 +AD 2 -2AD·FDcos∠ADF;

[0100]

[0101]

[0102]

[0103] ⅳFind ∠ADC

[0104] AC 2 =AD 2 +CD 2 -2AD·CDcos∠ADC,d 1 2 =d 3 2 +d 5 2 -2d 3 ·d 5 cos∠ADC;

[0105]

[0106] ⅴFind ∠FDE and FE (which can be expressed as D 1 )

[0107]

[0108]

[0109] ;in,

[0110] When the inclination angle between the jack-up platform and the oil production platform is too large, the distance between the two platforms cannot be expressed by a single midpoint distance between the two platforms, and the shortest distance between the two platforms is also required to represent the safe distance. Correspondingly, in some embodiments, obtaining the position and orientation of the platform 2 under test relative to the test platform 1 according to the distance and orientation of at least two points on the platform 2 under test relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device includes: selecting a first point and a second point on the platform 2 under test, and calculating the shortest distance between the platform 2 under test and the test platform 1 based on a triangle formed by any three of the first point, the second point, the first projection point, the first distance measuring device, the second distance measuring device, and the preset edge point of the test platform 1; wherein the first projection point is a projection point of the first distance measuring device or the second distance measuring device on the platform 2 under test, the preset edge point is an edge point of the test platform 1 closer to the platform 2 under test, the second projection point is a projection point of the preset edge point on the platform 2 under test, and the distance between the second projection point and the preset edge point is the shortest distance; wherein the distance and orientation of the first point and the second point relative to the first distance measuring device are respectively obtained according to the first distance data, and the distance and orientation of the first point and the second point relative to the second distance measuring device are respectively obtained according to the second distance data.

[0111] Optionally, the inclination angle of the measured platform relative to the test platform can be calculated based on the triangle formed by any three of the first point, the second point, the first ranging device, and the second ranging device, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first ranging device and the second ranging device are located is taken as the inclination angle of the measured platform relative to the test platform; further, the shortest distance is obtained based on the distance between the first projection point and the ranging device corresponding to the first projection point, and the inclination angle.

[0112] For example, reference may be made to Figure 6 , Figure 6FIG. 1 is a simplified schematic diagram of obtaining the shortest distance between the measured platform and the test platform in a method for measuring the distance between an offshore platform in position according to an embodiment of the present invention. As shown in FIG. Figure 4 Based on the original model shown in the figure, take the rightmost endpoint G of the test platform 1 (i.e. the edge point of the test platform 1 closer to the tested platform 2), and select its corresponding projection point H (i.e. the second projection point) on the tested platform 2 and its extension line. Take the corresponding projection point J (i.e. the first projection point) of the first distance measuring device, and take the point I where the projection of the rightmost endpoint G of the test platform 1 on CJ intersects, where CG is d 8 .

[0113] Combination Figure 6 As shown, the known conditions are the distance d from the first distance measuring device point C to the pile leg point A 1 d 2 Compared with the d solved above 6 , and the distance d from the edge point G of the test platform 1 to the first distance measuring device point C 8 . From the known conditions, we can know that the triangle in the figure is completely solvable. First, solve △ACJ to find CJ; then solve △CIG to find CI; because GH=IJ, the required GH is the length of IJ; finally, IJ=CJ-CI, and the required side IJ is found. The specific formula is as follows:

[0114] ⅰSeeking CJ

[0115]

[0116] ⅱSeek CI

[0117] CI=CGsinθ=d 8 sinθ.

[0118] ⅲFind GH (which can be expressed as D 2 ), GH = IJ;

[0119] in

[0120] In some embodiments, the on-site ranging method for an ocean platform also includes the following process, including the following steps: acquiring images of the platform 2 under test captured by at least two cameras, wherein the at least two cameras are arranged on the side of the test platform 1 close to the platform 2 under test; based on the images captured by the at least two cameras, obtaining depth information of the platform 2 under test to construct a three-dimensional image of the platform 2 under test, and fusing the obtained data describing the posture of the platform 2 under test relative to the test platform 1 with the three-dimensional image of the platform 2 under test.

[0121] In this embodiment, the method for obtaining the depth information of the platform 2 to construct a three-dimensional image of the platform 2 is not limited. In some embodiments, the depth information can be obtained by linear triangulation. Specifically, it is assumed that a first camera and a second camera are included, and there are projection matrices P1 and P2 respectively. For a point in space (X = [X, Y, Z, 1] T ), whose projections in the first camera and the second camera are x1 and x2 respectively. The goal of linear trigonometry is to find a point X in space given x1, x2, P1 and P2. For each camera projection, an equation related to the spatial point X can be obtained. For two cameras, a linear system is obtained, which can be expressed as AX=0, where A is a 4x4 matrix consisting of the two-dimensional projection, the projection matrix of the camera and some cross products. This linear system is usually singular and has no unique solution. However, the spatial point X is a vector in the non-zero space of this system. X can be found by calculating the singular value decomposition of A and taking the singular vector corresponding to its smallest singular value as the solution.

[0122] According to the relative positions of each camera device and the first distance measuring device and the second distance measuring device, the obtained data describing the position and posture of the measured platform 2 relative to the test platform 1 can be fused with the three-dimensional image of the measured platform 2.

[0123] In some embodiments, the method for in-situ ranging of an ocean platform also includes the following process: performing feature point matching on the two frames of images captured by the camera device, obtaining rotation information and translation information of the movement of the platform 2 under test based on the matched feature points in the two frames of images, and establishing a motion model of the platform 2 under test based on the three-dimensional image of the platform 2 under test.

[0124] Before extracting feature points and matching the image, the image may be filtered, and a Gaussian filter may be used but is not limited to it, to reduce noise in the image.

[0125] Optionally, the image feature extraction may use, but is not limited to, the Harris corner detection algorithm to find key points in the image. The basic idea of ​​Harris corner detection is to detect a small window (or neighborhood) in the image. When the window has a large change in all directions, the center point is considered to be a corner point. The following steps are included:

[0126] 1. Calculate the gradient of the image. You can use the Sobel filter or other methods to calculate the gradients Ix and Iy of the image in the x and y directions.

[0127] 2. Calculate the outer product of the gradient, which can be expressed as: IxIy.

[0129] 3. Construct a structure matrix. For each pixel (p, q), construct a structure matrix M in the window around it:

[0130] in, represents the sum over a window around position (x,y), typically using Gaussian weights.

[0131] 4. Calculate the response function. The Harris response function R is defined as:

[0132] R = det(M) - k(trace(M)) 2 ; where det(M) = λ 1 λ 2 、(trace(M)=λ 1 +λ 2 ) are two eigenvalues ​​of M and k is a constant (usually between 0.04 and 0.06).

[0133] 5. Threshold and non-maximum suppression. If a value of R is greater than a given threshold and is the largest in its neighborhood, the point is considered a corner point. Non-maximum suppression ensures that the detected corner point is a local maximum.

[0134] 6. Results. All pixels that meet the above conditions are marked as corner points.

[0135] Optionally, the Scale-invariant Feature Transform (SIFT) algorithm can be used, but not limited to, to generate descriptors for feature points. These descriptors can provide similar representations for the same physical point in different images, thereby facilitating matching. The SIFT algorithm includes the following steps and the key formula of SIFT:

[0136] 1. Difference of Gaussians (DoG)

[0137] In SIFT, we first construct a Gaussian pyramid in scale space. This is achieved by successively applying Gaussian filters to the original image. The Gaussian function is expressed as:

[0138]

[0139] DoG is obtained by subtracting a Gaussian image of one scale from a Gaussian image of another scale: D(x,y,σ)=(G(x,y,kσ)-G(x,y,σ))*I(x,y); where * represents the convolution operation, I(x,y) represents the original image, and k represents a fixed scale interval.

[0140] 2. Key point positioning

[0141] In order to locate the exact position and scale of the key points, it is necessary to perform Taylor expansion on the DoG function. By finding the zero point of the function, that is, the point where the derivative is zero, the extreme point can be located, which is usually done by solving a linear equation.

[0142] 3. Key point direction assignment

[0143] The gradient directions around each keypoint are calculated and formed into a histogram. This can be calculated using the following formula:

[0144]

[0145]

[0146] Where L(x,y) represents the image in scale space, m(x,y) and θ(x,y) are the gradient magnitude and direction at a given point, respectively. The descriptor is generated by sampling the gradient histogram around the keypoint. This produces a vector of a certain dimension (usually 128).

[0147] The motion model of the platform 2 under test is established based on the images collected by the camera device, including the motion model estimating the pose, inter-frame feature matching or active window extracting key frames. Adjacent frame matching points are performed based on the key frames, and 3D triangulation is performed to construct a 3D triangulated network to delete dynamic point features, and finally static point features are output. The ranging results are further optimized based on the static point features and the position between the ranging devices.

[0148] The process of estimating the pose of the motion model includes: matching the feature points in the previous and next frames, calculating the basic matrix using the matched feature points, and decomposing the relative rotation information and translation information from the basic matrix. The fundamental matrix (Fundamental Matrix, usually represented as F) can be used to describe the geometric relationship between the two camera views (or images). In particular, it describes the correspondence between the points in the first image and the points in the second image. For the matching points in the two images, the correspondence between these points can be described by the basic matrix. Mathematically, for the matching points x and x′ in the two images (usually expressed as homogeneous coordinates), the basic matrix satisfies the following conditions: x′ T Fx=0; wherein: x′ represents a point in the second image, x represents a point in the first image, and F represents a basic matrix.

[0149] The process of inter-frame feature matching includes: for the descriptors in the two frames, use the matching algorithm to find potential matching pairs, and analyze the matching results to remove false matches. The matching algorithm can use brute-force matching, which is also called Brute-Force matching. The basic idea is that for each feature descriptor in the first image, it is compared with all feature descriptors in the second image, and then the most similar one is found. When comparing and analyzing the two images, for each descriptor in the first image, a distance is calculated with each descriptor in the second image. For each descriptor, find the descriptor with the smallest distance (i.e., the most similar). This will provide corresponding points in the second image for the feature points in the first image.

[0150] In the image processing process, not every frame is used as a key frame. Frames with significant changes in scene or motion are selected, which helps reduce the amount of calculation and increase stability. Matching adjacent frames based on key frames is to use the feature points in the key frame to match the surrounding frames (previous and next frames) for feature matching. In a scene, not all points are stationary, i.e. static points. For example, if the movement of the hull during 3D modeling of the hull will generate dynamic points, the dynamic points are harmful to the establishment of a stable and accurate 3D model, so the dynamic points need to be detected and deleted.

[0151] This embodiment also provides an offshore platform in-situ ranging system, including:

[0152] The first distance measuring device and the second distance measuring device are respectively arranged on the side of the test platform 2 close to the tested platform 1, and are used to collect and obtain first distance data and second distance data respectively, wherein the first distance data includes the distance and orientation of each point within a preset range on the tested platform 2 relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the tested platform 2 relative to the second distance measuring device;

[0153] The comprehensive processing device is communicatively connected with the first distance measuring device and the second distance measuring device respectively, and is used to obtain the posture of the measured platform 2 relative to the test platform 1 according to the distance and orientation of at least two points on the measured platform 2 relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device, and according to the relative positions of the first distance measuring device and the second distance measuring device, so as to control the measured platform 2 to be in place.

[0154] The marine platform in-position ranging system of this embodiment uses the first ranging device and the second ranging device to respectively collect the distance and azimuth of each point on the measured platform within a preset range relative to the ranging device, and combines the distance and azimuth of the top point on the measured platform relative to the first ranging device and the second ranging device to obtain the position and attitude of the measured platform relative to the test platform. Compared with the prior art, it can improve the measurement accuracy of the relative position and attitude between the two platforms during the marine platform in-position process, provide technical support for marine platform in-position operations, improve work efficiency, and reduce accidents.

[0155] In some embodiments, the marine platform in-situ ranging system further includes:

[0156] At least two camera devices are respectively arranged on the side of the test platform 2 close to the tested platform 1, and the camera devices are used to capture images of the tested platform 2;

[0157] The comprehensive processing device is also used to obtain the depth information of the platform under test based on the images captured by the at least two camera devices to construct a three-dimensional image of the platform under test 2, and to fuse the obtained data describing the position and posture of the platform under test 2 relative to the test platform 1 with the three-dimensional image of the platform under test 2.

[0158] Optionally, the comprehensive processing device is also used to: perform feature point matching on the two frames of images captured by the camera device, obtain the rotation information and translation information of the movement of the platform 2 under test based on the matched feature points in the two frames of images, and establish a motion model of the platform 2 under test based on the three-dimensional image of the platform 2 under test.

[0159] It should be noted that the implementation method of the comprehensive processing device obtaining the posture of the measured platform 2 relative to the test platform 1 according to the distance and azimuth of at least two points on the measured platform 2 relative to the first ranging device and the distance and azimuth relative to the second ranging device, and according to the relative positions of the first ranging device and the second ranging device, as well as the implementation method of the comprehensive processing device obtaining the depth information of the measured platform according to the image captured by the camera device to construct a three-dimensional image, and the implementation method of establishing the motion model of the measured platform 2, can all refer to the corresponding implementation methods described in the above embodiments of the in-situ ranging method for the marine platform, and will not be repeated here.

[0160] Optionally, the comprehensive processing device runs the following threads: a first thread for acquiring the image captured by the camera device; a second thread for acquiring the first distance data captured by the first distance measuring device; a third thread for acquiring the second distance data captured by the second distance measuring device; a fourth thread for copying the distance data acquired by the second thread and the third thread based on the image acquired by the first thread, and fusing the image and the distance data; a fifth thread for copying the image acquired by the first thread, constructing a three-dimensional image of the platform under test based on the image, and copying the fusion result acquired by the fourth thread, and displaying the three-dimensional image and the fusion result.

[0161] Exemplarily, the integrated processing device includes six threads in total, as follows:

[0162] Thread 1 is used to obtain images captured by the camera device and store the data, with an efficiency of 25 to 30 frames per second; Thread 2 is used to obtain the first distance data collected by the first ranging device and store the data, with an efficiency of 200ms per operation, for example, the first ranging device is a laser radar; Thread 3 is used to obtain the second distance data collected by the second ranging device and store the data, with an efficiency of 200ms per operation, for example, the second ranging device is a millimeter wave radar.

[0163] Thread 4 is used to copy the distance data obtained by thread 2 and thread 3 based on the image obtained by thread 1, and fuse the image and distance data; thread 4 is responsible for the fusion of the real scene image, taking thread 1 as a blueprint, by copying the information existing in thread 2 and thread 3, using the algorithm to realize data fusion, and running the program with a running time of 40ms (25fps).

[0164] Thread 5 is used to copy the image obtained by thread 1, construct a 3D image of the platform under test based on the image, and copy the fusion result obtained by thread 4, and display the 3D image and fusion result. Thread 5 copies frame buffer 1 and algorithm results, and processes and displays the frame using OpenCV.

[0165] Thread 6 is similar to thread 4 and is responsible for the fusion of the front view and the top view. The frequency is still once every 40ms (i.e. 25fps).

[0166] For reference Figure 7-1 to Figure 12 ,in, Figure 7-1 The following is a principle flow chart of thread 1 of an offshore platform in-situ ranging system provided by an embodiment. Figure 7-2 This is a principle flow chart of thread 2 of an offshore platform in-situ ranging system provided by an embodiment. Figure 7-3 This is a principle flow chart of thread 3 of an offshore platform in-situ ranging system provided by an embodiment. Figure 8 An initialization flow chart of an offshore platform in-situ ranging system provided by an embodiment is provided. Fig. 9 This is a principle flow chart of thread 4 of an offshore platform in-situ ranging system provided by an embodiment, Fig.10 This is a principle flow chart of thread 5 of an offshore platform in-situ ranging system provided by an embodiment, Fig.11 This is a principle flow chart of thread 6 of an offshore platform in-situ ranging system provided by an embodiment, Fig.12 A stop action flow chart of an in-situ ranging system for an offshore platform is provided as an embodiment. The control system is running, and the system initialization settings are turned on, including interface initialization, variable and cache initialization, as well as camera device, laser radar, millimeter wave radar initialization, and measurement thread initialization, and storage space is allocated for each thread. The camera device collects images and transmits data to the data processing box, the millimeter wave radar and laser radar collect data and transmit data to the data processing box, and the comprehensive processing device collects data from the four data processing boxes for comprehensive processing and analysis. The comprehensive processing device performs normalization processing, fast Fourier transform, smoothing filtering, denoising, parameter estimation, spectrum shifting, low-pass filtering and other steps on the communication signal in sequence, and analyzes the data of multiple ranging devices simultaneously.

[0167] The above is a detailed introduction to a method and system for in-situ ranging of an offshore platform provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for measuring distance on an offshore platform, characterized in that: include: Acquire first distance data collected by a first distance measuring device and second distance data collected by a second distance measuring device, wherein the first distance measuring device and the second distance measuring device are respectively arranged on a side of the test platform close to the platform under test, the first distance data includes the distance and orientation of each point within a preset range on the platform under test relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the platform under test relative to the second distance measuring device; According to the relative positions of the first distance measuring device and the second distance measuring device, matching the positions of the first distance data and the second distance data corresponding to the same point on the measured platform; The position of the measured platform relative to the test platform is obtained according to the distance and orientation of at least two points on the measured platform relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device, so as to control the measured platform in place.

2. The method for measuring distance on an offshore platform according to claim 1, characterized in that: On the side of the test platform close to the platform under test, a plurality of distance measuring devices are arranged in sequence from far to near around the central axis of the side, and two of the plurality of distance measuring devices are respectively used as the first distance measuring device and the second distance measuring device.

3. The method for measuring distance on an offshore platform according to claim 1, characterized in that: Obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises: Selecting a first point and a second point on the platform under test, and calculating the inclination angle of the platform under test relative to the test platform based on a triangle formed by any three of the first point, the second point, the first distance measuring device, and the second distance measuring device, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first distance measuring device and the second distance measuring device are located is taken as the inclination angle of the platform under test relative to the test platform; The distances and orientations of the first point and the second point relative to the first distance measuring device are obtained according to the first distance data, and the distances and orientations of the first point and the second point relative to the second distance measuring device are obtained according to the second distance data.

4. The method for measuring distance on an offshore platform according to claim 1, characterized in that: Obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises: Selecting a first point, a second point, and a second midpoint on the platform under test, and calculating the midpoint distance between the platform under test and the test platform based on a triangle formed by any three of the first point, the second point, the second midpoint, the first distance measuring device, the second distance measuring device, and the first midpoint; The second midpoint is the midpoint of the platform under test, and the position of the first point relative to the second midpoint and the position of the second point relative to the first midpoint are both determined, the first midpoint is the midpoint of the test platform, and the position of the first distance measuring device relative to the first midpoint and the position of the second distance measuring device relative to the first midpoint are both determined; Among them, the distances and orientations of the first point, the second point, and the second midpoint relative to the first ranging device are obtained respectively according to the first distance data, and the distances and orientations of the first point, the second point, and the second midpoint relative to the second ranging device are obtained respectively according to the second distance data.

5. The method for measuring distance on an offshore platform according to claim 1, characterized in that: Obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises: Selecting a first point and a second point on the platform under test, and calculating the shortest distance between the platform under test and the test platform based on a triangle formed by any three of the first point, the second point, the first projection point, the first distance measuring device, the second distance measuring device, and a preset edge point of the test platform; The first projection point is the projection point of the first distance measuring device or the second distance measuring device on the platform under test, the preset edge point is the edge point of the test platform closer to the platform under test, the second projection point is the projection point of the preset edge point on the platform under test, and the distance between the second projection point and the preset edge point is the shortest distance; The distances and orientations of the first point and the second point relative to the first distance measuring device are obtained according to the first distance data, and the distances and orientations of the first point and the second point relative to the second distance measuring device are obtained according to the second distance data.

6. The method for measuring distance on an offshore platform according to claim 5, characterized in that: Obtaining the position and orientation of the platform under test relative to the test platform according to the distance and orientation of at least two points on the platform under test relative to the first ranging device and the distance and orientation relative to the second ranging device comprises: Based on the triangle formed by any three of the first point, the second point, the first distance measuring device, and the second distance measuring device, the inclination angle of the platform under test relative to the test platform is calculated, wherein the angle between the straight line where the first point and the second point are located and the straight line where the first distance measuring device and the second distance measuring device are located is taken as the inclination angle of the platform under test relative to the test platform; The shortest distance is obtained according to the distance between the first projection point and the distance measuring device corresponding to the first projection point, and the tilt angle.

7. The method for measuring distance on an offshore platform according to claim 1, characterized in that: Also includes: Acquire images of the platform under test captured by at least two camera devices, wherein the at least two camera devices are disposed on a side of the test platform close to the platform under test; According to the images captured by the at least two cameras, depth information of the platform under test is obtained to construct a three-dimensional image of the platform under test, and the obtained data describing the posture of the platform under test relative to the test platform is fused with the three-dimensional image of the platform under test.

8. The method for measuring distance on an offshore platform according to claim 1, characterized in that: Also includes: Perform feature point matching on the two frames of images captured by the camera device. The rotation information and translation information of the measured platform movement are obtained according to the matched feature points in the two preceding and succeeding frames of the image, and the movement model of the measured platform is established based on the three-dimensional image of the measured platform.

9. An offshore platform in-situ ranging system, characterized in that: include: The first distance measuring device and the second distance measuring device are respectively arranged on the side of the test platform close to the platform under test, and are used to collect and obtain first distance data and second distance data respectively, wherein the first distance data includes the distance and orientation of each point within a preset range on the platform under test relative to the first distance measuring device, and the second distance data includes the distance and orientation of each point within the preset range on the platform under test relative to the second distance measuring device; The comprehensive processing device is communicatively connected with the first distance measuring device and the second distance measuring device respectively, and is used to obtain the posture of the measured platform relative to the test platform according to the distance and orientation of at least two points on the measured platform relative to the first distance measuring device and the distance and orientation relative to the second distance measuring device, and according to the relative positions of the first distance measuring device and the second distance measuring device, so as to control the measured platform to be in place.

10. The marine platform in-situ distance measurement system according to claim 9, characterized in that: Also includes: At least two camera devices, respectively arranged on the side of the test platform close to the platform under test, and the camera devices are used to capture images of the platform under test; The comprehensive processing device is further used to obtain the depth information of the platform under test to construct a three-dimensional image of the platform under test based on the images captured by the at least two camera devices, and fuse the obtained data describing the position and posture of the platform under test relative to the test platform with the three-dimensional image of the platform under test; The integrated processing device runs the following threads: a first thread, for acquiring images captured by the camera device; A second thread is used to obtain the first distance data collected by the first distance measuring device; A third thread is used to obtain the second distance data collected by the second distance measuring device; The fourth thread is used to copy the distance data obtained by the second thread and the third thread based on the image obtained by the first thread, and fuse the image and the distance data; The fifth thread is used to copy the image obtained by the first thread, construct a three-dimensional image of the platform under test according to the image, copy the fusion result obtained by the fourth thread, and display the three-dimensional image and the fusion result.

Images