Shallow water target positioning system and method

Abstract

The invention relates to the technical field of underwater positioning, and discloses a shallow water target positioning system and method. The shallow water target positioning system comprises a water surface supporting platform, underwater operation equipment, a pull rope sensor, a first reference point and a space pose sensor, the pull rope sensor is arranged between the underwater operation equipment and the water surface supporting platform, and the first reference point is arranged at the water surface connecting part of the water surface supporting platform and the pull rope sensor. The water surface support platform is further provided with a space pose sensor for detecting the space coordinates of the first reference point, and the method comprises the steps that underwater operation equipment is arranged, and a space coordinate system is constructed according to connecting points; the length data of the pull rope sensor and the space coordinates of the first reference point are obtained, the coordinates of the underwater operation equipment are calculated according to the length data, the space coordinates of the first reference point and the space coordinates of the connecting point, and the coordinates of the underwater operation equipment can be rapidly and accurately obtained through the reference point and the positioning steel wire rope. The problem that underwater operation equipment in a shallow water area cannot be accurately positioned is solved.

Description

Technical Field

[0001] The present invention relates to the field of underwater positioning technology, and in particular to a shallow water target positioning system and method. Background Art

[0002] When conducting hydrological research and exploring seabed resources, underwater operating equipment is needed to meet survey needs. However, in the process of performing survey tasks, it is necessary to obtain the location of underwater operating equipment in real time to assist in the survey mission.

[0003] Although the commonly used GPS positioning and optical positioning on land have relatively high accuracy, the electromagnetic waves attenuate too much in water, so these systems commonly used on shore cannot be used underwater. The commonly used methods underwater are ultra-short baseline, short baseline or long baseline based on hydroacoustics. When the target is deep in the water, these positioning systems can achieve relatively good positioning effects. However, in shallow water areas, such as inland lakes, inland rivers and offshore areas, these acoustic positioning systems cannot accurately obtain the target's location information due to the acoustic detection angle, water pollution and other reasons, and thus cannot perform geographic annotation on the survey results. Once the underwater operating equipment is detached, it will cause serious economic losses. The existing shallow water area positioning is often achieved by setting a pull rope at a fixed end on the shore, connecting the other end to the operating equipment, obtaining the angle of the pull rope through a sensor, and then obtaining the position of the operating equipment based on the pull rope length and trigonometric functions.

[0004] However, this calculation method cannot accurately determine the angle of a single axis because the mechanical sensor has the phenomenon of X, Y, and Z axis angle coupling when obtaining the angle, resulting in the inability to effectively measure the position of the operating equipment. In addition, please refer to Figure 1 When the mechanical sensor obtains the angle, it needs to be subjected to the force of the rope to feedback the angle information. Figure 1 In the figure, when the pull rope moves from point E to point F, the mechanical sensor cannot be subjected to force and therefore cannot feedback angle information. The EF segment becomes a dead zone, making it impossible to accurately measure the position of the underwater operating equipment. Summary of the invention

[0005] The present invention provides a shallow water target positioning system and method to solve the problem that existing underwater operating equipment in shallow water areas cannot be accurately positioned.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions: In a first aspect, the present invention provides a shallow water target positioning system, comprising a surface support platform, an underwater operation device, a pull-wire sensor, and a spatial posture sensor, wherein the pull-wire sensor is arranged between the underwater operation device and the surface support platform, a first reference point is arranged at a surface connection portion between the surface support platform and the pull-wire sensor, and the surface support platform is further provided with a spatial posture sensor for detecting the spatial coordinates of the first reference point; The pull rope sensor comprises a sensor body and a positioning wire rope. One end of the sensor body is arranged on the underwater operation equipment, and the positioning wire rope is connected to the water surface support platform.

[0007] Furthermore, a second reference point is set at the water surface connection portion between the water surface support platform and the pull rope sensor.

[0008] Furthermore, the underwater operation equipment is also connected to the surface support platform through an optoelectronic watertight cable, and a plurality of buoys are installed on the outer surface of the optoelectronic watertight cable.

[0009] Furthermore, the surface support platform is installed with a support frame and a winch, one end of the optoelectronic watertight cable is connected to the underwater operating equipment, and the other end is connected to the winch on the surface support platform through the support frame.

[0010] In a second aspect, the present invention provides a shallow water target positioning method, which is applied to any of the shallow water target positioning systems described above, and the shallow water target positioning method comprises: Step 1: Deploy the underwater operation equipment underwater to carry out underwater operations, and build a spatial coordinate system based on the connection points between the pull-wire sensor and the surface support platform; Step 2: Obtain the length data of the rope sensor and the spatial coordinates of the first reference point, and calculate the coordinates of the underwater operating equipment in the spatial coordinate system based on the length data of the rope sensor, the first reference point and the spatial coordinates of the connection point.

[0011] Further, a second reference point is set at the water surface connection portion between the water surface support platform and the pull rope sensor; The step 2 also includes: obtaining the length data of the pull-wire sensor, and obtaining the spatial coordinates of the first reference point and the second reference point, and calculating the coordinates of the underwater working equipment in the spatial coordinate system according to the length data of the pull-wire sensor, the spatial coordinates of the first reference point and the second reference point.

[0012] Furthermore, the coordinates of the underwater working equipment in the spatial coordinate system are calculated based on the length data of the rope sensor, the spatial coordinates of the first reference point, and the spatial coordinates of the connection point or the second reference point in combination with the Pythagorean theorem and similar triangles. The coordinates of the underwater working equipment are calculated by the length data of the rope sensor, the spatial coordinates of the first reference point and the connection point, or by the length data of the rope sensor, the spatial coordinates of the first reference point and the spatial coordinates of the second reference point.

[0013] Furthermore, the coordinates of the underwater operating equipment in the space coordinate system are calculated by the following formula: ; ; ; in, , , They are the X, Y, and Z axis coordinate positions of the underwater operating equipment in the space coordinate system; , , are the X, Y, and Z axis coordinate positions of the connection point or the second reference point in the spatial coordinate system respectively; It is the length data of the rope sensor; , , They are respectively the ratios of the spatial vectors of the X, Y, and Z axes of the coordinates of the first reference point to the length from the first reference point to the water surface support platform.

[0014] Furthermore, the , , Calculate using the following formula: ; ; ; in, , , They are respectively the X, Y, and Z axis coordinate positions of the first reference point in the spatial coordinate system.

[0015] Beneficial effects: The present invention provides a shallow water target positioning system and method, which can quickly calculate the coordinates of underwater working equipment in a space coordinate system by combining a first reference point with a connection point, using similar triangles and the Pythagorean theorem, thereby solving the problem that underwater working equipment cannot be accurately positioned in existing shallow water areas due to acoustic detection opening angles, water pollution, and the like; The problem that mechanical sensors cannot accurately measure angles is effectively solved by combining the spatial posture sensor with the first reference point. One end of the wire rope of the pull-rope sensor is set at one end of the surface support platform. The spatial posture sensor is used to directly measure the angles of the X, Y, and Z axes without contact. There is no dead zone and no angle coupling, which will not affect the positioning of underwater operating equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a mechanical encoder of the background technology of the present invention subjected to the force transmitted by the pull rope; Figure 2 is a schematic diagram of a shallow water target positioning system according to an embodiment of the present invention; Figure 3 A detailed schematic diagram of a shallow water target positioning system according to an embodiment of the present invention; Figure 4 is a system block diagram of a shallow water target positioning system according to an embodiment of the present invention; Figure 5 is a flow chart of a shallow water target positioning method according to an embodiment of the present invention; Figure 6 A schematic diagram of setting a first reference point B and a second reference point A of a shallow water target positioning method according to an embodiment of the present invention; Figure 7 Schematic diagram of setting the third reference point C in the verification process of the shallow water target positioning method according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the solution of a quadratic equation with AD variables in the verification process of the shallow water target positioning method according to an embodiment of the present invention.

[0017] In the figure, 1. Surface support platform; 2. Underwater operation equipment; 3. Pull rope sensor; 31. Sensor body; 32. Positioning wire rope; 4. First reference point; 41. Second reference point; 5. Spatial posture sensor; 6. Photoelectric watertight cable; 61. Float; 11. Support frame; 12. Winch. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only a 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 are within the scope of protection of the present invention.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the common meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components.

[0020] See also Figure 2-3 The embodiment of the present application provides a shallow water target positioning system, including a surface support platform 1, an underwater working equipment 2, a pull-wire sensor 3 and a spatial posture sensor 5. The pull-wire sensor 3 is arranged between the underwater working equipment 2 and the surface support platform 1. A first reference point 4 is set at the surface connection part between the surface support platform 1 and the pull-wire sensor 3. The surface support platform 1 is also provided with a spatial posture sensor 5 for detecting the spatial coordinates of the first reference point 4, and a second reference point 41 is set at the surface connection part between the surface support platform 1 and the pull-wire sensor 3.

[0021] Specifically, the pull-rope sensor 3 includes a sensor body 31 and a positioning wire rope 32 . One end of the sensor body 31 is disposed on the underwater operating equipment 2 , and the positioning wire rope 32 is connected to the surface support platform 1 .

[0022] The underwater operation equipment 2 is also connected to the surface support platform 1 through an optoelectronic watertight cable 6 , and a plurality of buoys 61 are installed on the outer surface of the optoelectronic watertight cable 6 .

[0023] The surface support platform 1 is installed with a support frame 11 and a winch 12 , one end of the optoelectronic watertight cable 6 is connected to the underwater operating equipment 2 , and the other end is connected to the winch 12 on the surface support platform 1 through the support frame 11 .

[0024] The spatial posture sensor 5 includes a plurality of camera probes, and all of them are horizontally arranged above the first reference point 4 .

[0025] For corresponding Figure 4 , a control computer and an above-water optical terminal are set on the surface support platform 1, connected to an optical space posture system composed of a space posture sensor 5, and a pressure-resistant electronic warehouse is set in the underwater operation equipment 2, in which an underwater optical terminal, a local controller and a pull rope sensor 3 are set; The local controller collects data from the rope sensor 3 and the length data of the positioning wire rope 32 through the serial port, and then transmits it to the underwater optical terminal through Ethernet. The underwater optical terminal converts the electrical signal into an optical signal, and transmits it to the surface optical terminal through the optical fiber in the optoelectronic watertight cable 6. The surface optical terminal converts the optical signal into an electrical signal, and transmits it to the control computer through Ethernet. The optical space posture system transmits the spatial coordinates of the first reference point 4 and the second reference point 41 on the positioning wire rope 32 to the control computer through Ethernet. The control computer calculates the coordinates of the underwater operating equipment 2 by acquiring the spatial coordinates of the first reference point 4 and the second reference point 41 and the length data of the positioning wire rope 32.

[0026] In this embodiment, the control computer calculates the coordinates of the underwater working equipment 2 through the spatial coordinates of the first reference point 4 and the second reference point 41 and the length data of the positioning wire rope 32. In other embodiments where the second reference point 41 is not set and only the connection point is set, the control computer calculates the coordinates of the underwater working equipment 2 through the spatial coordinates of the first reference point 4 and the connection point and the length data of the positioning wire rope 32.

[0027] See also Figure 5-6 The embodiment of the present application also provides a shallow water target positioning method, which is applied to a shallow water target positioning system. The shallow water target positioning system includes a surface support platform 1, an underwater working device 2, a pull-wire sensor 3, a first reference point 4, and a spatial posture sensor 5. The pull-wire sensor 3 is arranged between the underwater working device 2 and the surface support platform 1. The first reference point 4 is arranged at the surface connection portion between the surface support platform 1 and the pull-wire sensor 3. The surface support platform 1 is also provided with a spatial posture sensor 5 for detecting the spatial coordinates of the first reference point 4, and a second reference point 41 is arranged at the surface connection portion between the surface support platform 1 and the pull-wire sensor 3. Shallow water target positioning methods include: Step 1: deploy the underwater operation equipment 2 underwater to carry out underwater operations, and construct a spatial coordinate system based on the connection points between the pull-wire sensor 3 and the surface support platform 1; In this embodiment, the entire process is completed in a laboratory, a shallow water target positioning system is set up accordingly, and the underwater operation equipment 2 is placed at a certain distance from the surface support platform 1 to simulate actual underwater operations.

[0028] See also Figure 7 In this embodiment, a third reference point is set on the underwater working equipment 2 for verification, the spatial coordinates of the third reference point are obtained by the spatial posture sensor 5, and the distance between the third reference point and the positioning wire rope 32 is measured by a measuring instrument; Wherein O is the connection point, B is the first reference point 4, A is the second reference point 41, C is the third reference point, and D is the position of the positioning wire rope 32 on the underwater operation equipment 2.

[0029] Step 2: Obtain the length data of the rope sensor 3 and the spatial coordinates of the first reference point 4 and the second reference point 41, and calculate the coordinates of the underwater working equipment 2 in the spatial coordinate system based on the length data of the rope sensor 3 and the spatial coordinates of the first reference point 4 and the second reference point 41.

[0030] In this embodiment, the coordinates of the underwater working equipment 2 in the spatial coordinate system are calculated based on the length data of the rope sensor, the spatial coordinates of the first reference point 4, and the spatial coordinates of the second reference point 41, combined with the Pythagorean theorem and similar triangles. In other embodiments, only the connection point can be set according to actual conditions, and there is no need to set the second reference point 41. The calculation is based on the length data of the rope sensor, the spatial coordinates of the first reference point 4, and the spatial coordinates of the connection point, combined with the Pythagorean theorem and similar triangles.

[0031] The length data AD of the rope sensor 3 obtained at this time is 2601mm, the spatial coordinates of the first reference point 4 are (-784.351, -348.054, 1496.193), the spatial coordinates of the second reference point 41 are (-922.27, -349.677, 1544.523), and the spatial coordinates of the third reference point are (1596.323, -160.879, 776.904). The distance CD between the third reference point and the positioning wire rope 32 is 195mm.

[0032] The coordinates of the underwater working equipment 2 in the space coordinate system are calculated by the following formula: ; ; ; in, , , are respectively the X, Y, and Z axis coordinate positions of the underwater operating equipment 2 in the space coordinate system; , , are respectively the X, Y, and Z axis coordinate positions of the second reference point 41 in the spatial coordinate system; In this embodiment, , , are respectively the X, Y, and Z axis coordinate positions of the second reference point 41 in the spatial coordinate system. In other embodiments where only the connection point is set and the second reference point 41 is not set , , They are the X, Y, and Z axis coordinate positions of the connection point in the spatial coordinate system respectively; is the length data of the rope sensor 3 (in this embodiment, AD length); , , They are respectively the ratios of the spatial vectors of the X, Y, and Z axes of the coordinates of the first reference point 4 and the length from the first reference point 4 to the water surface support platform 1.

[0033] , , Calculate using the following formula: ; ; ; in, , , They are respectively the X, Y and Z axis coordinate positions of the first reference point 4 in the space coordinate system.

[0034] Through the above formula, according to the Pythagorean theorem, it can be known that the distance AB between the first reference point 4 and the second reference point 41 is: ; Further calculations yield =0.944, =0.011, =-0.331, combined with the length data S of the rope sensor 3 obtained, which is 2601 mm, it can be calculated =1533.074mm, =-321.066mm, =683.592mm, thus the coordinates of the underwater working equipment 2 in the space coordinate system are (1533.074, -321.066, 683.592).

[0035] The distance AC between the second reference point 41 and the third reference point is calculated again in combination with the Pythagorean theorem as follows: ; in, , , is the spatial coordinate of the third reference point.

[0036] The distance BC between the first reference point 4 and the third reference point is calculated as: ; Consider the first reference point 4, the second reference point 41 and the third reference point as a triangle and calculate using the cosine theorem. The cosine of : ; The position of the positioning wire rope 32 on the underwater working equipment 2, the second reference point 41 and the third reference point are regarded as a triangle. Combining the cosine theorem, it can be known that: ; The CD length is 195 mm, which is the distance between the third reference point and the positioning wire rope 32. The AC length is 2639.733 mm. The cosine of is 0.9973, so the above equation is a quadratic equation about the AD variable, and the solution is is 2653.762mm, is 2611.450mm, see Figure 8 ,in , from this we can see that The length is the length from the positioning wire rope 32 on the underwater operation equipment 2 to the second reference point 41. =2611.450mm is substituted as S in the following formula: ; ; ; in, , , Obtained during the accounting process The coordinate position of the point on the X, Y, and Z axes in the spatial coordinate system; get , , .

[0037] The coordinates of point D calculated by the draw wire sensor 3 and the coordinates of point D calculated by inverse cosine of the third reference point are further analyzed: Table 1: Analysis of the coordinates of point D calculated by the draw wire sensor 3 and the coordinates of point D calculated by the third reference point

[0038] It can be seen from Table 1 that the deviation between the coordinates of point D calculated using the pull-wire sensor 3 and the coordinates of point D calculated using the third reference point is very small. Therefore, it can be explained that the technical solution recorded in the present application can accurately obtain the position information of the underwater working equipment 2 by setting a reference point on the pull-wire sensor 3 and calculating the spatial coordinates of the reference point in combination with the length data of the positioning wire rope 32.

[0039] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A shallow water target positioning system, characterized in that: The invention comprises a surface support platform (1), an underwater operation device (2), a pull-wire sensor (3), and a spatial posture sensor (5), wherein the pull-wire sensor (3) is arranged between the underwater operation device (2) and the surface support platform (1), a first reference point (4) is arranged at the surface connection portion between the surface support platform (1) and the pull-wire sensor (3), and the surface support platform (1) is further provided with a spatial posture sensor (5) for detecting the spatial coordinates of the first reference point (4); The pull-wire sensor (3) comprises a sensor body (31) and a positioning steel wire rope (32); one end of the sensor body (31) is arranged on the underwater operation equipment (2), and the positioning steel wire rope (32) is connected to the surface support platform (1).

2. The shallow water target positioning system according to claim 1, characterized in that: A second reference point (41) is provided at the surface connection portion between the surface support platform (1) and the pull-wire sensor (3).

3. The shallow water target positioning system according to claim 1, characterized in that: The underwater operation equipment (2) is also connected to the surface support platform (1) via an optoelectronic watertight cable (6), and a plurality of buoys (61) are installed on the outer surface of the optoelectronic watertight cable (6).

4. The shallow water target positioning system according to claim 3, characterized in that: The surface support platform (1) is equipped with a support frame (11) and a winch (12); one end of the photoelectric watertight cable (6) is connected to the underwater operating equipment (2), and the other end is connected to the winch (12) on the surface support platform (1) through the support frame (11).

5. A shallow water target positioning method, characterized in that: The shallow water target positioning system applied to any one of claims 1 to 4, wherein the shallow water target positioning method comprises: Step 1: deploying underwater operation equipment (2) underwater to carry out underwater operations, and constructing a spatial coordinate system based on the connection points between the pull-wire sensor (3) and the surface support platform (1); Step 2: Obtain the length data of the pull-wire sensor (3) and the spatial coordinates of the first reference point (4), and calculate the coordinates of the underwater operation equipment (2) in the spatial coordinate system based on the length data of the pull-wire sensor (3), the first reference point (4) and the spatial coordinates of the connection point.

6. The shallow water target positioning method according to claim 5, characterized in that: A second reference point (41) is provided at the surface connection portion between the surface support platform (1) and the pull-wire sensor (3); The step 2 further comprises: obtaining the length data of the pull-wire sensor (3), and obtaining the spatial coordinates of the first reference point (4) and the second reference point (41), and calculating the coordinates of the underwater operation equipment (2) in the spatial coordinate system based on the length data of the pull-wire sensor (3), the spatial coordinates of the first reference point (4) and the second reference point (41).

7. The shallow water target positioning method according to claim 6, characterized in that: The coordinates of the underwater working equipment (2) in the spatial coordinate system are calculated based on the length data of the pull rope sensor (3), the spatial coordinates of the first reference point (4), the spatial coordinates of the connection point or the second reference point (41) in combination with the Pythagorean theorem and similar triangles.

8. The shallow water target positioning method according to claim 7, characterized in that: The coordinates of the underwater working equipment (2) in the space coordinate system are calculated by the following formula: ； ； ； in, , , are respectively the X, Y and Z axis coordinate positions of the underwater operating equipment (2) in the space coordinate system; , , are respectively the X, Y and Z axis coordinate positions of the connection point or the second reference point (41) in the spatial coordinate system; is the length data of the rope sensor (3); , , They are respectively the ratios of the spatial vectors of the X, Y, and Z axes of the coordinates of the first reference point (4) and the length from the first reference point (4) to the water surface support platform (1).

9. The shallow water target positioning method according to claim 8, characterized in that: Said , , Calculate using the following formula: ； ； ； in, , , are respectively the X, Y and Z axis coordinate positions of the first reference point (4) in the spatial coordinate system.

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