Underwater robot for marine riser detection

Abstract

The invention relates to the technical field of pipeline inspection, and discloses an underwater robot for marine riser detection, the underwater robot comprises a first annular seat, a driving assembly and a second annular seat, the bottom of the second annular seat is sleeved in an annular limiting groove of the first annular seat, and the second annular seat and the first annular seat are coaxially arranged; the fixed end of the driving assembly is connected with the first annular base, and the output end of the driving assembly is connected with the second annular base and used for driving the second annular base to rotate relative to the first annular base. The inner circumferential surface of the first annular seat is provided with at least two telescopic positioning assemblies, the positioning assemblies are used for abutting against the outer wall surface of the marine riser, the inner circumferential surface of the second annular seat is provided with at least one detection unit, and the detection units are used for detecting the outer wall surface of the marine riser and collecting images. Therefore, the driving assembly can adjust the detection direction of the detection unit in the second annular seat, and compared with manual adjustment and change of the detection direction, the operation is convenient, the detection continuity is high, and the detection effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline inspection, and more particularly to an underwater robot for detecting marine risers. Background Art

[0002] In the existing technology, underwater robots are mostly equipped with a single probe. During pipeline inspection, staff need to manually adjust the rotation of the underwater robot to change the detection direction of the detection probe. This is inconvenient to use, has low detection continuity, and reduces detection efficiency.

[0003] In summary, how to improve the detection efficiency of underwater robots is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an underwater robot for marine riser detection, in which the driving component can drive the second annular seat to rotate relative to the second annular seat to change the detection direction of the detection unit in the second annular seat, and the operation is convenient, the detection continuity is high, and the detection effect is high.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An underwater robot for marine riser inspection comprises a first annular seat, a drive assembly, and a second annular seat, wherein the bottom of the second annular seat is sleeved in an annular limiting groove of the first annular seat, and the second annular seat is coaxially arranged with the first annular seat;

[0007] The fixed end of the driving assembly is connected to the first annular seat, and the output end of the driving assembly is connected to the second annular seat, for driving the second annular seat to rotate relative to the first annular seat;

[0008] The inner circumference of the first annular seat is provided with at least two retractable positioning assemblies, which are used to abut against the outer wall of the marine riser. The inner circumference of the second annular seat is provided with at least one detection unit, which is used to detect and capture images of the outer wall of the marine riser.

[0009] Preferably, the positioning assembly includes an electric telescopic rod, a fixed end of the electric telescopic rod is connected to the inner circumferential surface of the first annular seat, and a movable end of the electric telescopic rod is connected to the abutment seat.

[0010] Preferably, a pulley mounting seat is slidably provided in the abutment seat, the pulley mounting seat is connected to the abutment seat via an adjusting rod, and at least one rotatable pulley is provided in the pulley mounting seat;

[0011] The adjusting rod comprises a telescopic rod with adjustable length and a spring sleeved outside the telescopic rod, one end of the spring is connected to the pulley mounting seat, and the other end of the spring is connected to the abutment seat.

[0012] Preferably, the detection unit is slidingly connected to the inner wall surface of the second annular seat through a lifting assembly, and the lifting assembly includes a fixed seat, and the fixed seat is provided with a lifting screw along the axial direction of the second annular seat, and the external threaded sleeve of the lifting screw is provided with a movable seat, and the detection unit is detachably connected to the movable seat.

[0013] Preferably, the movable base is provided with a mounting base, and the detection unit is connected to the mounting base via a connecting base;

[0014] One of the mounting seat and the connecting seat is provided with a limiting groove, which is arranged along the axial direction of the second annular seat, and the other is provided with a limiting protrusion that is snap-fitted with the limiting groove, and the mounting seat and the connecting seat are bolted.

[0015] Preferably, the first annular seat includes a first mounting seat and a second mounting seat, and the first mounting seat and the second mounting seat are connected by a first connecting member;

[0016] The second annular seat includes a first rotating seat and a second rotating seat, and the first rotating seat and the second rotating seat are connected by a second connecting member.

[0017] Preferably, an alignment component is provided between the first annular seat and the second annular seat, and the alignment component comprises a spring, a U-shaped connecting rod and an alignment seat provided on the outer periphery of the second annular seat;

[0018] The outer periphery of the first annular seat is provided with a mounting hole for installing the spring, and one end of the U-shaped connecting rod is connected to the mounting hole through the spring. When the other end of the U-shaped connecting rod is inserted into the alignment hole of the alignment seat, the connecting surface of the first annular seat and the connecting surface of the second annular seat are located in the same vertical plane.

[0019] Preferably, the driving assembly includes a driving motor, a driving gear and a gear portion arranged on the outer periphery of the second annular seat, the driving motor is arranged on the outer periphery of the first annular seat through a motor mounting seat, the driving gear is sleeved on the output shaft of the driving motor, and the gear portion is meshed with the driving gear.

[0020] The underwater robot for marine riser detection provided by the present invention has a driving component that can drive the second annular seat to rotate relative to the first annular seat, thereby changing the detection direction of the detection unit arranged in the second annular seat. Compared with manual adjustment to change the detection direction, the operation is convenient, the detection continuity is high, and the detection efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0022] Figure 1 This is a schematic structural diagram of a specific embodiment of an underwater robot for marine riser inspection provided by the present invention;

[0023] Figure 2 Schematic diagram of the assembly of an underwater robot for marine riser inspection and a marine riser in the main viewing direction;

[0024] Figure 3 for Figure 2 A schematic cross-sectional view in the main viewing direction;

[0025] Figure 4 for Figure 3 A partial enlarged view of area A in the middle;

[0026] Figure 5 A schematic diagram of the assembly of an underwater robot for marine riser inspection and a marine riser in a top-down view;

[0027] Figure 6 A schematic diagram of the structure of the positioning component.

[0028] Figures 1-6 middle:

[0029] 01-marine riser; 10-first annular seat; 101-first mounting seat; 102-second mounting seat; 103-connecting seat; 201-driving motor; 202-driving gear; 30-second annular seat; 301-first rotating seat; 302-second rotating seat; 303-gear part; 40-positioning assembly; 401-electric telescopic rod; 402-abutting seat; 403-adjusting rod; 4031-telescopic rod; 4032-spring; 404-pulley mounting seat; 405-anti-slip pad; 406-traveling wheel; 407-auxiliary wheel; 501-fixed seat; 502-lifting screw; 503-moving seat; 504-mounting seat; 505-connecting seat; 506-detection unit; 601-alignment seat; 602-U-shaped connecting rod; 603-spring. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0031] The core of the present invention is to provide an underwater robot for marine riser detection. The driving component can drive the second annular seat to rotate relative to the second annular seat to change the detection direction of the detection unit in the second annular seat. It is easy to operate, has high detection continuity and high detection effect.

[0032] The underwater robot for marine riser inspection provided by the present invention includes a first annular seat 10, a drive assembly, and a second annular seat 30. The bottom of the second annular seat 30 is sleeved in the mounting groove on the top surface of the first annular seat 10, and the second annular seat 30 is coaxially arranged with the first annular seat 10.

[0033] The fixed end of the driving assembly is connected to the first annular seat 10, and the output end of the driving assembly is connected to the second annular seat 30, for driving the second annular seat 30 to rotate relative to the first annular seat 10;

[0034] The inner circumference of the first annular seat 10 is provided with at least two retractable positioning assemblies 40, which are used to abut against the outer wall of the marine riser 01. The inner circumference of the second annular seat 30 is provided with at least two detection units 506, which are used to detect and capture images of the outer wall of the marine riser 01.

[0035] Please refer to Figure 1 The first annular seat 10 is sleeved on the outer surface of the marine riser 01 to be inspected through the positioning assembly 40. The positioning assembly 40 can be specifically configured as a positioning rod assembly, a positioning plate assembly, etc. The number of contact points between the positioning assembly 40 and the outer wall of the marine riser 01 is not limited and can be one, two, or more.

[0036] However, it should be noted that to prevent the first annular seat 10 from being excessively offset relative to the pipeline of the marine riser 01, which would cause the detection unit 506 in the second annular seat 30 to contact or collide with the outer wall of the marine riser 01, the first annular seat 10 is usually provided with at least three contact points with the outer wall of the marine riser 01, so that the first annular seat 10 and the marine riser 01 can be adjusted to be coaxial based on the principle of three-point circle determination.

[0037] In order to meet the detection requirements of marine risers 01 with different outer diameters, the radial length of the positioning assembly 40 is adjustable so that the positioning assembly 40 abuts against the outer wall surface of the marine risers 01 with different outer diameters, thereby allowing the first annular seat 10 to be sleeved on the outside of the marine risers 01 with different outer diameters.

[0038] The first annular seat 10 is an annular structure, and its specific shape is determined according to the shape of the marine riser 01 in actual production. When the marine riser 01 is a circular tube, the first annular seat 10 is usually set to a circular ring structure; when the marine riser 01 is a square tube, the first annular seat 10 is mostly set to a square ring structure.

[0039] In order to facilitate the lowering and recovery of the underwater robot, the outer periphery of the first annular seat 01 is provided with a connecting seat 103 for connecting to an external retracting and extending mechanism. The connecting seat 103 is mostly connected to an external retracting and extending mechanism such as a winch by stretching.

[0040] The second annular seat 30 is coaxially sleeved on one end of the first annular seat 10 and is connected to the first annular seat 10 via a drive assembly. When the drive assembly is in operation, it drives the second annular seat 30 to rotate relative to the first annular seat 10, thereby changing the detection direction of the detection unit 506 inside the second annular seat 30, thereby performing 360° detection and image acquisition of the marine riser 01.

[0041] The detection unit 506 is used to detect and capture images of the marine riser 01. The detection unit 506 mainly includes a magnetic probe and / or an ultrasonic probe for detecting wear, corrosion and leakage of the marine riser 01, and a camera or a camera for capturing images of the outer wall of the marine riser 01 to detect deformation of the marine riser 01 and marine biological coverage.

[0042] The specific number, type and model of the magnetic probe, ultrasonic probe and camera in the detection unit 506 are determined according to the actual production needs and with reference to the existing technology, and will not be described in detail here;

[0043] The number of detection units 506 is determined based on factors such as the detection range of the detection unit 506 and the preset cost. The more the number, the higher the cost, but the larger the total detection range of the detection unit 506, and the shorter the time required for full-circle detection of the marine riser 01.

[0044] In order to prevent the second annular seat 30 from being separated from the first annular seat 10 when the underwater robot is folded or unfolded, the second annular seat 30 is clamped in the annular limiting groove at the bottom of the first annular seat 10. Figure 1 , the first annular seat 10 and the second annular seat 30 can be provided with split structures in the circumferential direction;

[0045] The first annular seat 10 can also be set as an integrated structure in the circumferential direction, but in this case the first annular seat 10 is provided with an annular seat body of an annular mounting seat and a limiting end cover at the upper end, and the annular mounting groove and the limiting end cover cooperate to limit the second annular seat 30.

[0046] During operation, the external retraction and extension mechanism controls the underwater robot to move along the outer wall of the marine riser 01 toward the terminal end through a pull rope, and lowers the underwater robot to the starting end of the marine riser 01 to be inspected; controls the positioning assembly to extend inward until the positioning assembly abuts against the outer wall of the marine riser 01, positioning the first annular seat 10 at a certain axial position on the marine riser 01; controls the driving assembly to rotate the second annular seat 30 relative to the first annular seat 10, driving the detection unit 506 to circle the marine riser 01 for inspection.

[0047] In this embodiment, the driving component can drive the second annular seat 30 to rotate relative to the first annular seat 10, thereby changing the detection direction of the detection unit 506 arranged in the second annular seat 30. Compared with manually adjusting and changing the detection direction, the operation is convenient, the detection continuity is high, and the detection efficiency is high.

[0048] It should be noted that when the underwater robot is working, the first annular seat 10 and the second annular seat 30 are both sleeved outside the marine riser 01. The first annular seat 10 and the second annular seat 30 can be set as an integrated structure in the circumferential direction. However, they need to be sleeved outside the marine riser 01 during the construction of the marine riser 01 to prevent the first annular seat 10 and the second annular seat 30 from being unable to pass through the filter separator after the marine riser 01 is connected to the filter separator of the offshore platform.

[0049] In order to facilitate the assembly of the first annular seat 10 and the marine riser 01, the first annular seat 10 and the second annular seat 30 are usually provided with a split structure in the circumferential direction. Figure 1 The first annular seat 10 includes a first mounting seat 101 and a second mounting seat 102, and the first mounting seat 101 and the second mounting seat 102 are connected by a first connecting member; the second annular seat 30 includes a first rotating seat 301 and a second rotating seat 302, and the first rotating seat 301 and the second rotating seat 302 are connected by a second connecting member.

[0050] Usually, the first mounting seat 101 and the second mounting seat 102 are symmetrically distributed about the vertical symmetry plane of the first annular seat 10, and the second rotating seat 301 and the second rotating seat 302 are symmetrically distributed about the vertical symmetry plane of the second annular seat 30 to facilitate the processing of the first annular seat 10 and the second annular seat 30.

[0051] The first connecting member and the second connecting member can both be configured as common connecting members such as fastening bolts, connecting pins, connecting buckles, etc., and their specific types can be the same, such as Figure 1 The first annular seat 10 and the second annular seat 30 shown both use fastening bolts as connecting members, but they may also be different.

[0052] It should be noted that, since the second annular seat 30 is connected to the output end of the drive assembly, the second connecting member should avoid the mating portion where the drive assembly is connected to the second annular seat 30 to avoid interfering with the drive assembly driving the second annular seat 30 to rotate relative to the first annular seat 10;

[0053] The first connecting member should avoid the connection between the drive assembly and the first annular seat 10 so as to reserve sufficient installation space for the first connecting member.

[0054] On the basis of the above embodiment, in order to facilitate the alignment of the first annular seat 10 and the second annular seat 30 during the assembly and disassembly process, an alignment assembly can be provided between the first annular seat 10 and the second annular seat 30. The alignment assembly includes a spring 603, a U-shaped connecting rod 602, and an alignment seat 601 provided on the outer periphery of the second annular seat 30.

[0055] The outer periphery of the first annular seat 10 is provided with a mounting hole for installing the spring 603. One end of the U-shaped connecting rod 602 is connected to the mounting hole through the spring 603. When the other end of the U-shaped connecting rod 602 is inserted into the alignment hole of the alignment seat 601, the connecting surface of the first annular seat 10 is connected to the connecting surface of the second annular seat 30.

[0056] Therefore, when the underwater robot needs to be disassembled, the second annular seat 30 can be rotated manually or mechanically. When the U-shaped connecting rod 602 can be inserted into the alignment hole of the alignment seat 601, the connecting surface of the first annular seat 10 and the connecting seat of the second annular seat 30 are located in the same vertical plane; at this time, the first connecting member and the second connecting member can be removed, and the first rotating seat 301 can be separated from the first mounting seat 101, and the second rotating seat 302 can be separated from the second mounting seat 102.

[0057] Based on the above embodiment, the structure of the positioning assembly 40 is defined. The positioning assembly may include an electric telescopic rod 401, the fixed end of the electric telescopic rod 401 is connected to the inner circumferential surface of the first annular seat 10, and the movable end of the electric telescopic rod 401 is connected to the abutment seat 402.

[0058] The electric telescopic rod 401 is connected to an external control device by signal transmission, so that personnel on an offshore platform or the like can remotely control the extension and retraction of the electric telescopic rod 401 and other movements of the underwater robot. The length and extension range of the electric telescopic rod 401 are determined according to the inner diameter of the first annular seat 10 and the diameter range of the marine riser 01 in actual production, and will not be further described here.

[0059] The movable end of the electric telescopic rod 401 is provided with an abutment seat 402, which is used to contact and abut against the outer wall surface of the marine riser 01; the abutment seat 402 can be specifically configured as a plate-shaped structure or an arc-shaped structure.

[0060] In order to increase the contact area between the abutment seat 402 and the outer wall of the marine riser 01 and thus enhance the friction therebetween, the abutment seat 402 is often configured as an arc-shaped structure. The radius and central angle of the abutment seat 403 are determined based on the diameter range of the marine riser 01 in actual production and will not be further elaborated here.

[0061] In order to enhance the friction between the abutment seat 402 and the outer wall of the marine riser 01, the inner surface of the abutment seat 402 relatively close to the marine riser 01 may be provided with an anti-slip pad 405 and / or an anti-slip coating. The anti-slip pad 405 is mostly made of rubber, and the surface of the anti-slip pad 405 may be provided with anti-slip protrusions or anti-slip textures.

[0062] In this embodiment, the electric telescopic rod 401 can be used to extend and retract to adjust the axial position of the abutment seat 402, so that the abutment seat 402 can abut or separate from the outer wall of the marine riser 01, thereby adjusting the connection relationship between the first annular seat 10 and the marine riser 01. This has a simple structure, convenient adjustment, and high adjustment accuracy.

[0063] Preferably, a pulley mounting seat 404 may be provided in the abutment seat 402, the pulley mounting seat 404 being connected to the abutment seat 402 via an adjusting rod 403, and at least one rotatable pulley being provided in the pulley mounting seat 404;

[0064] The adjusting rod 403 includes a telescopic rod 4031 with adjustable length and a spring 4032 sleeved on the telescopic rod 4031 . One end of the spring 4032 is connected to the pulley mounting seat 404 , and the other end of the spring 4032 is connected to the abutment seat 402 .

[0065] Please refer to Figure 6 The telescopic rod 4031 includes a telescopic rod body and at least one level of sleeve. The sleeves at each level and the sleeves and the telescopic rod body are nested so that the sleeves at each level can slide relative to adjacent sleeves or the telescopic rod body, thereby adjusting the length of the telescopic rod 4031.

[0066] The spring 4032 is sleeved outside the telescopic rod 4031, one end of the spring 4032 is connected to the pulley mounting seat 404, and the other end of the spring 4032 is connected to the abutment seat 402; to prevent the spring 4032 from rusting, the surface of the spring 4032 should be provided with an anti-rust coating.

[0067] When the pulley in the pulley mounting seat 404 abuts against the outer wall of the marine riser 01, the electric telescopic rod 401 is controlled to continue to extend, and the telescopic rod 4031 contracts inward under the action of pressure. At the same time, the spring 4032 is compressed and accumulates elastic potential energy until the outer end surface of the abutment seat 402 abuts against the outer wall of the marine riser 01, so that the first annular seat 10 is positioned at a certain axial position on the marine riser 01.

[0068] When the detection unit 506 completes detection and image acquisition, the electric telescopic rod 401 is controlled to retract inward, causing the outer end surface of the abutment seat 402 to separate from the outer wall of the marine riser 01. At this time, the adjustment rod 403 is reset under the elastic restoring force of the spring 4032, and the pulley of the pulley mounting seat 404 abuts against the outer wall of the marine riser 01.

[0069] At least one rotatable pulley is provided in the pulley mounting seat. The pulley can be a traveling wheel 406 driven by a power element such as a servo motor, or can be an unpowered auxiliary wheel 407. Figure 6 A running wheel 406 driven by a servo motor is provided in the center of the pulley mounting seat, and auxiliary wheels 407 are provided on both sides of the running wheel 406.

[0070] In this embodiment, the electric telescopic rod 401 can cooperate with the adjustment rod 403 to change the contact position between the positioning assembly and the marine riser 01, thereby changing the friction between the positioning assembly and the marine riser 01. This can not only stably position the first annular seat 10 at a certain axial position on the marine riser 01, but also facilitate the up and down movement of the first annular seat 10 relative to the marine riser 01.

[0071] On the basis of the above embodiment, a detection unit 506 can be set to be slidably connected to the inner wall surface of the second annular seat 30 through a lifting assembly. The lifting assembly includes a fixed seat 501, and the fixed seat 501 is provided with a lifting screw 502 along the axial direction of the second annular seat 30. The lifting screw 502 is provided with a movable seat 503 on the external thread sleeve, and the detection unit 506 is detachably connected to the movable seat 503.

[0072] Therefore, when the lifting screw 502 is driven to rotate, the movable seat 503 is lifted and lowered along the extension direction of the lifting screw 502, that is, the axial direction of the second annular seat 30, thereby driving the detection unit 506 to be lifted and lowered along the axial direction of the second annular seat 503, while the axial position of the first annular seat 10 remains unchanged, and the detection range of the detection unit 506 is expanded.

[0073] Of course, the lifting assembly can also be replaced by a linear motion mechanism such as a lifting electric cylinder, a synchronous belt assembly, etc.

[0074] The detection unit 506 and the movable base 503 are detachably connected to facilitate replacement and maintenance of the detection unit 506 , and the two can be connected by means of a snap connection, a bolt connection, a pin connection, or the like.

[0075] Preferably, the movable base 503 may be provided with a mounting base 504 , and the detection unit 506 may be connected to the mounting base 504 via a connecting base 505 ;

[0076] One of the mounting seat 504 and the connecting seat 505 is provided with a limiting groove, which is arranged along the axial direction of the second annular seat 30, and the other is provided with a limiting protrusion that is snap-fitted with the limiting groove, and the mounting seat 504 and the connecting seat 505 are bolted together.

[0077] Among them, the limiting groove and the limiting protrusion are snap-fitted to enhance the connection stability between the movable seat 503 and the detection unit 506; the fastening bolts are used to fix the mounting seat 504 and the mounting seat 505 to connect the movable seat 503 and the detection unit 506.

[0078] Based on the above embodiment, the drive assembly includes a drive motor 201, a driving gear 202 and a gear portion 303 arranged on the outer periphery of the second annular seat 30. The drive motor 201 is arranged on the outer periphery of the first annular seat 10 through a motor mounting seat, the driving gear 202 is sleeved on the output shaft of the drive motor 201, and the gear portion 303 is meshed with the driving gear 202.

[0079] Therefore, when the driving motor 201 rotates, the driving motor 201 drives the driving gear 202 to rotate, and further drives the gear portion 303 meshing with the driving gear 202 to rotate, thereby driving the second annular seat 30 to rotate relative to the first annular seat 10 .

[0080] It should be noted that the first and second annular seats 10 and 30, the first mounting seat 101 and the second mounting seat 102, the first rotating seat 301 and the second rotating seat 302, and the first connecting member and the second connecting member in this application document are only used to distinguish the difference in position and do not contain any limitation on the order.

[0081] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0082] The above describes in detail the underwater robot for marine riser inspection 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 intended only to facilitate understanding of the method and core concept of the present invention. It should be noted that those skilled in the art may make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An underwater robot for marine riser inspection, characterized in that: The invention comprises a first annular seat (10), a driving assembly and a second annular seat (30), wherein the bottom of the second annular seat (30) is sleeved in the annular limiting groove of the first annular seat (10), and the second annular seat (30) is coaxially arranged with the first annular seat (10); The fixed end of the driving assembly is connected to the first annular seat (10), and the output end of the driving assembly is connected to the second annular seat (30), for driving the second annular seat (30) to rotate relative to the first annular seat (10); The inner circumference of the first annular seat (10) is provided with at least two retractable positioning assemblies (40), and the positioning assemblies (40) are used to abut against the outer wall surface of the marine riser (01); the inner circumference of the second annular seat (30) is provided with at least one detection unit (506), and the detection unit (506) is used to detect and capture images of the outer wall surface of the marine riser (01).

2. The underwater robot for marine riser inspection according to claim 1, characterized in that: The positioning assembly (40) comprises an electric telescopic rod (401), the fixed end of the electric telescopic rod (401) is connected to the inner circumference of the first annular seat (10), and the movable end of the electric telescopic rod (401) is connected to the abutment seat (402).

3. The underwater robot for marine riser inspection according to claim 2, characterized in that: A pulley mounting seat (404) is slidably provided in the abutting seat (402), the pulley mounting seat (404) is connected to the abutting seat (402) via an adjusting rod (403), and at least one rotatable pulley is provided in the pulley mounting seat (404); The adjusting rod (403) comprises a telescopic rod (4031) with adjustable length and a spring (4032) sleeved on the telescopic rod (4031), one end of the spring (4032) is connected to the pulley mounting seat (404), and the other end of the spring (4032) is connected to the abutting seat (402).

4. The underwater robot for marine riser inspection according to claim 1, characterized in that: The detection unit (506) is slidably connected to the inner wall surface of the second annular seat (30) through a lifting assembly, and the lifting assembly includes a fixed seat (501), and the fixed seat (501) is provided with a lifting screw (502) along the axial direction of the second annular seat (30), and the lifting screw (502) is externally threaded and provided with a movable seat (503), and the detection unit (506) is detachably connected to the movable seat (503).

5. The underwater robot for marine riser inspection according to claim 4, characterized in that: The movable seat (503) is provided with a mounting seat (504), and the detection unit (506) is connected to the mounting seat (504) via a connecting seat (505); One of the mounting seat (504) and the connecting seat (505) is provided with a limiting groove, which is arranged along the axial direction of the second annular seat (30), and the other is provided with a limiting protrusion that is engaged with the limiting groove, and the mounting seat (504) and the connecting seat (505) are bolted together.

6. The underwater robot for marine riser inspection according to any one of claims 1 to 5, characterized in that: The first annular seat (10) comprises a first mounting seat (101) and a second mounting seat (102), wherein the first mounting seat (101) and the second mounting seat (102) are connected via a first connecting member; The second annular seat (30) comprises a first rotating seat (301) and a second rotating seat (302), wherein the first rotating seat (301) and the second rotating seat (302) are connected via a second connecting member.

7. The underwater robot for marine riser inspection according to claim 6, characterized in that: An alignment component is provided between the first annular seat (10) and the second annular seat (30), the alignment component comprising a spring (603), a U-shaped connecting rod (602), and an alignment seat (601) provided on the outer periphery of the second annular seat (30); The outer periphery of the first annular seat (10) is provided with a mounting hole for mounting the spring (603), one end of the U-shaped connecting rod (602) is connected to the mounting hole via the spring (603), and when the other end of the U-shaped connecting rod (602) is inserted into the alignment hole of the alignment seat (601), the connecting surface of the first annular seat (10) and the connecting surface of the second annular seat (30) are located in the same vertical plane.

8. The underwater robot for marine riser inspection according to any one of claims 1 to 5, characterized in that: The driving assembly comprises a driving motor (201), a driving gear (202), and a gear portion (303) arranged on the outer periphery of the second annular seat (30); the driving motor (201) is arranged on the outer periphery of the first annular seat (10) via a motor mounting seat; the driving gear (202) is sleeved on the output shaft of the driving motor (201); and the gear portion (303) is meshedly connected with the driving gear (202).

Images