An AUV-based seabed in-situ testing structure

Abstract

This invention relates to the fields of marine engineering geological survey and marine geotechnical engineering technology, specifically to an AUV-based in-situ seabed testing structure, comprising a body, a suction anchor, and a probe assembly. The suction anchor is installed at the bottom of the body, and the probe assembly is installed inside the body. The suction anchor has a cover for contacting the seabed and forming a sealed chamber. The probe assembly includes a first driving component, a probe unit, and a linkage component. The first driving component is installed inside the body, and the probe unit extends out of the body in response to the first driving component to penetrate the seabed soil. The linkage component, in response to the first driving component, drives the suction anchor to perform a drainage action to increase the negative pressure inside the sealed chamber. This solves the technical problem of suction anchor sealing failure caused by changes in penetration resistance in existing AUV seabed static cone penetration tests.

Description

Technical Field

[0001] This invention relates to the fields of marine engineering geological survey and marine geotechnical engineering technology, specifically to an in-situ seabed testing structure based on an AUV. Background Technology

[0002] With the development of autonomous underwater vehicle (AUV) technology, integrating static cone penetration testing (CPT) equipment into AUV platforms to achieve in-situ geotechnical testing on the seabed has become an important research direction in the field of marine engineering geological surveys. Suction anchor devices have been introduced into this system because they can provide reliable anchoring force for the AUV. Their basic working principle is as follows: after the AUV settles on the seabed, the suction anchor's casing cuts into the seabed sediment to form a sealed cavity. A water pump then pumps out seawater from the cavity, creating a pressure difference between the inside and outside, thus firmly adhering the AUV to the seabed and providing the necessary reaction force for subsequent CPT penetration. However, in existing technologies, the suction anchor and the CPT penetration mechanism are mechanically independent and operate sequentially, with no mechanical coupling between them. The upward reaction force generated by CPT penetration relies entirely on the static adsorption force of the suction anchor for passive cancellation. This architecture has significant inherent flaws: First, to ensure anchoring safety under maximum penetration force conditions, the suction anchor and pump system must be redundantly designed according to ultimate loads, resulting in a large system size and excessive weight, severely restricting the AUV platform's carrying capacity and underwater maneuverability; Second, the suction force of the suction anchor is established and fixed before CPT penetration. When the CPT probe encounters hard interlayers, gravel layers, or abrupt formation interfaces during penetration, the penetration resistance increases sharply instantaneously, and the electric cylinder and probe system generate severe mechanical vibration and impact loads. This vibration is transmitted to the suction anchor housing through the AUV. The shell may cause instantaneous micro-cracks or loosening at the initial sealing interface between the shell edge and seabed sediments. Driven by huge hydrostatic pressure, external seawater can enter the shell cavity through the gap, causing a sudden drop in the pressure difference between the inside and outside of the shell, reducing the effective adsorption area of ​​the suction anchor, and the anchoring force will decrease sharply. Due to the lack of adaptive and synchronous negative pressure adsorption force, the AUV platform will eventually be pulled up, laterally slip, or even overturned under the combined action of penetration reaction force, causing test interruption or equipment damage. This makes it impossible for the AUV to cope with sudden changes in reaction force when encountering complex strata, and the success rate of operation is difficult to guarantee.

[0003] Therefore, in view of this, the inventors proposed an AUV-based in-situ seabed testing structure to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide an in-situ seabed testing structure based on an AUV to solve the technical problem of suction anchor seal failure caused by changes in penetration resistance in existing AUV seabed static cone penetration tests.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An AUV-based in-situ seabed testing structure includes a body, a suction anchor, and a probe assembly. The suction anchor is installed at the bottom of the body, and the probe assembly is installed inside the body. The suction anchor has a cover for contacting the seabed and forming a sealed chamber. The probe assembly includes a first driving component, a probe unit, and a linkage component. The first driving component is installed in the body of the machine. The probe unit is connected to the output end of the first driving component. The linkage component is connected between the suction anchor and the output end of the first driving component. The probe unit extends from the body in response to the first driving member to penetrate the seabed soil, and the linkage component drives the suction anchor to perform a drainage action in response to the first driving member, so as to increase the negative pressure in the sealed chamber.

[0006] Furthermore, the probe unit includes a piston cylinder fixedly installed inside the machine body, and the upper surface of the piston cylinder is connected to the linkage component; A screw is rotatably installed inside the piston cylinder, and a telescopic rod is slidably installed at the bottom of the piston cylinder. The telescopic rod is slidably connected to the piston cylinder, and a threaded hole is opened inside the telescopic rod. The screw is threadedly connected to the threaded hole.

[0007] Furthermore, the first driving component includes a drive motor, which is fixedly installed in the machine body, and the output shaft of the drive motor is connected to the linkage component; when the drive motor drives the screw to rotate through the linkage component, the telescopic rod extends or retracts along the axial direction of the piston cylinder.

[0008] Furthermore, a water pumping channel is provided in the middle of the suction anchor, and a bidirectional pipe is connected to the end of the water pumping channel. A bidirectional water pump is connected to the end of the bidirectional pipe, and the bidirectional water pump is fixedly installed inside the body.

[0009] Furthermore, the linkage component includes a housing, a first piston cylinder and a second piston cylinder fixedly disposed on the housing, a first piston chamber is disposed inside the first piston cylinder, a second piston chamber is disposed inside the second piston cylinder, a first sliding plug is slidably connected to the first piston chamber, and a second sliding plug is slidably connected to the second piston cylinder. A first connecting shaft is rotatably connected inside the housing. The first connecting shaft extends out of the housing and is coaxially connected to the drive motor. A first connecting block and a second connecting block are fixedly connected to the first connecting shaft. The first connecting shaft is coaxially fixedly connected to the screw. A first connecting rod is hinged to the first connecting block, and the first connecting rod is hinged to the first sliding plug. A second connecting rod is hinged to the second connecting block, and the second connecting rod is hinged to the second sliding plug.

[0010] Furthermore, the first piston chamber is connected to a first inlet pipe and a first outlet pipe, and the first inlet pipe is equipped with a first check valve. The second piston chamber is connected to a second inlet pipe and a second outlet pipe, and the second inlet pipe is equipped with a second check valve. The first inlet pipe is connected to the pumping channel.

[0011] Furthermore, the body includes a power propulsion module, which includes two main thrusters and four vertical thrusters; the two main thrusters are arranged at the rear of the body, the two vertical thrusters are arranged at the front of the body, and the other two vertical thrusters are arranged in the middle of the body; the two vertical thrusters located in the middle of the body are tilted to the left and right sides at preset angles with the vertical plane as the center line.

[0012] Furthermore, it also includes a buoyancy adjustment module, which includes a hydraulic pump, an oil bladder, and a pressure chamber. The pressure chamber is installed inside the body, the oil bladder is located at the bottom of the body, and the hydraulic pump is connected to an oil pipe. The two ends of the oil pipe are respectively connected to the oil bladder and the pressure chamber.

[0013] Furthermore, the bottom edge of the casing is provided with a continuous circular cutting edge.

[0014] Furthermore, a cone tip resistance sensor, a sidewall friction sensor, and a pore water pressure sensor are installed at the bottom of the telescopic rod.

[0015] The beneficial effects of this invention are: This invention couples the probe insertion action and the suction anchor negative pressure establishment process to the same first driving component through a linkage component, achieving synchronous and parallel driving of the penetration operation and anchoring reinforcement. It also automatically strengthens the anchoring force when the probe encounters a hard layer causing increased load, forming a positive feedback mechanism where the greater the penetration resistance, the stronger the negative pressure adsorption. Specifically, after the first driving component is activated, its output power simultaneously drives the probe unit to extend and penetrate the seabed soil, and drives the dual plungers in the linkage component to alternately pump water, continuously increasing the negative pressure in the suction anchor sealing chamber and firmly adsorbing the machine to the seabed. The linkage component adopts a dual-plunger coordinated pumping structure in which the first and second water inlet pipes are connected in parallel to the same sealed chamber and each outlet is through an independent one-way valve. When the probe encounters a hard layer during penetration, causing the motor load to increase, the reciprocating amplitude and pumping frequency of the two sets of plungers increase synchronously. The drainage capacity increases in the same direction as the load increases, so that the negative pressure establishment speed and stable adsorption force are adaptively enhanced. At the same time, since the drainage power of the linkage component comes entirely from the rotation output of the first driving component, there is no need to add an additional pumping power source, effectively controlling the energy consumption and space occupation inside the machine body, and realizing the organic unity of on-demand enhancement of anchoring reaction force and structural simplification.

[0016] Other advantages, objectives, and features of this application will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from practice of this application. The objectives and other advantages of this application may be realized and obtained through the detailed embodiments described below. Attached Figure Description

[0017] Figure 1 This is a bottom view of the underwater in-situ testing structure based on an AUV according to the present invention. Figure 2 This is a top view schematic diagram of the AUV-based in-situ seabed testing structure of the present invention. Figure 3 for Figure 1 A partial structural diagram; Figure 4 This is a cross-sectional schematic diagram of the in-situ seabed testing structure based on AUV according to the present invention; Figure 5 This is a schematic diagram showing the connection between the first and second control rudders in the AUV-based in-situ seabed testing structure of the present invention. Figure 6 This is a schematic diagram of the connection structure between the suction anchor and the probe assembly in the AUV-based in-situ seabed testing structure of the present invention. Figure 7 This is a schematic diagram of the first control rudder in the AUV-based in-situ seabed testing structure of the present invention; Figure 8 This is a schematic diagram of the second control rudder in the AUV-based in-situ seabed testing structure of the present invention; Figure 9 This is a schematic diagram of the overall structure of the linkage component in this invention; Figure 10 This is a cross-sectional structural diagram of the linkage component in this invention.

[0018] The components include: body 1, suction anchor 2, pumping channel 21, bidirectional water pump 22, bidirectional pipeline 23, probe rod assembly 3, cover 31, first driving component 32, drive motor 321, probe rod unit 33, piston cylinder 331, screw 332, telescopic rod 333, linkage component 34, outer shell 341, first piston cylinder 342, first piston chamber 3421, first sliding plug 3422, second piston cylinder 343, second piston chamber 3431, second sliding plug 3432, first connecting shaft 3433, first connecting block 3434, second connecting block 3435, first connecting rod 3436, second connecting rod 3437, first water inlet pipe 3441, first water outlet pipe 3442, second water inlet pipe 3443, and second water outlet pipe 3447. 444. Power propulsion module 4. Main thruster 41. Vertical thruster 42. Buoyancy adjustment module 5. Hydraulic pump 51. Oil bladder 52. First control rudder 6. First support frame 61. First wing member 62. First rotating shaft 621. First wing plate 622. First connector 623. Second control rudder 7. Fixing plate 71. Second wing member 72. Second rotating shaft 721. Second wing plate 722. Second connector 723. Second drive member 8. Drive unit 81. Mounting plate 811. Rotating shaft 812. Third connecting block 813. First drive rod 82. First connecting rod 821. Second connecting rod 822. Third connecting rod 823. Second drive rod 83. Fourth connecting rod 831. Fifth connecting rod 832. Sixth connecting rod 833. Detailed Implementation

[0019] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] This embodiment proposes an in-situ seabed testing structure based on an AUV, such as... Figures 1 to 10As shown, the device includes a body 1, a suction anchor 2, and a probe assembly 3. The suction anchor 2 is installed at the bottom of the body 1, and the probe assembly 3 is installed inside the body 1. The suction anchor 2 has a cover 31 for contacting the seabed and forming a sealed chamber. The probe assembly 3 includes a first drive member 32, a probe unit 33, and a linkage member 34. The first drive member 32 is installed inside the body 1, the probe unit 33 is connected to the output end of the first drive member 32, and the linkage member 34 is connected between the suction anchor 2 and the output end of the first drive member 32. The probe extends out of the body 1 in response to the first drive member 32 to penetrate the seabed soil, and the linkage member 34 drives the suction anchor 2 to perform a drainage action in response to the first drive member 32 to increase the negative pressure in the sealed chamber.

[0022] In this embodiment, after the body 1 descends to the predetermined measuring point and settles on the seabed, the suction anchor 2 installed at the bottom of the body 1, with its casing 31, comes into contact with the seabed sediment, forming an initial sealed chamber under the weight of the body 1 itself. Subsequently, the first drive unit 32 is activated, and the power at its output end is transmitted simultaneously along two paths. On one hand, it drives the probe unit 33 to move, causing the probe to extend from the bottom of the body 1 and penetrate into the seabed soil to perform in-situ testing. On the other hand, it drives the linkage component 34 to move. Since the linkage component 34 is connected between the suction anchor 2 and the output end of the first drive unit 32, this action causes the suction anchor 2 to perform drainage work, continuously pumping out the seawater in the sealed chamber, creating a pressure difference between the inside and outside of the chamber, thereby continuously increasing the negative pressure in the sealed chamber, firmly adhering the body 1 to the seabed, and providing a stable and reliable anchoring reaction force for the probe penetration. The probe penetration action and the negative pressure establishment process of the suction anchor 2 are synchronously driven by the same first drive unit 32, and the two are executed in parallel.

[0023] In a preferred embodiment, the probe unit 33 includes a piston cylinder 331 fixedly installed inside the body 1, with its upper surface connected to the linkage component 34. A screw 332 is rotatably disposed inside the piston cylinder 331, and a telescopic rod 333 is slidably disposed at the bottom of the piston cylinder 331. The telescopic rod 333 is slidably connected to the piston cylinder 331 and can extend or retract into the piston cylinder 331. A threaded hole is provided inside the telescopic rod 333, and the screw 332 is threadedly connected to the threaded hole. In a preferred embodiment, the first driving component 32 includes a drive motor 321 fixedly installed inside the body 1, with its output shaft connected to the linkage component 34. When the drive motor 321 drives the screw 332 to rotate through the linkage component 34, the telescopic rod 333 extends or retracts along the axial direction of the piston cylinder 331.

[0024] In this embodiment, after the first driving member 32 is activated, its output power is transmitted to the screw 332 inside the piston cylinder 331 via the linkage member 34, driving the screw 332 to rotate around its own axis inside the piston cylinder 331. Since the telescopic rod 333 is slidably disposed at the bottom of the piston cylinder 331 and maintains an axial sliding fit with the piston cylinder 331, and the threaded hole opened inside the telescopic rod 333 forms a threaded transmission pair with the screw 332, when the screw 332 rotates, the telescopic rod 333 is limited to sliding along the axial direction of the piston cylinder 331 and cannot rotate with the screw 332. The rotational motion is then converted into linear motion of the telescopic rod 333 along the axial direction of the piston cylinder 331 through the helical transmission action of the threaded pair. When the screw 332 rotates forward, the telescopic rod 333 extends out of the body 1 from the bottom of the piston cylinder 331 under the threaded drive, inserting the sensor installed at its end into the seabed soil; when the screw 332 rotates in reverse, the telescopic rod 333 slides in the opposite direction along the axial direction and retracts into the piston cylinder 331, realizing the retrieval of the probe. In this structure, the upper surface of the piston cylinder 331 is connected to the linkage component 34, which ensures that the power transmission path between the linkage component 34 and the probe unit 33 is closed and the structure is compact, so that the single rotation output of the first driving component 32 can simultaneously drive the screw 332 to rotate and the suction anchor 2 to drain water.

[0025] In a preferred embodiment, a water pumping channel 21 is provided in the middle of the suction anchor 2, and a bidirectional pipe 23 is connected to the end of the water pumping channel 21. A bidirectional water pump 22 is connected to the end of the bidirectional pipe 23, and the bidirectional water pump 22 is fixedly installed inside the body 1.

[0026] In this embodiment, after the body 1 is seated, the bidirectional water pump 22, which is fixedly installed inside the body 1, is started. It is connected to the pumping channel 21 opened in the middle of the suction anchor 2 through the bidirectional pipe 23. The seawater in the sealed chamber is pumped out along the pumping channel 21 and the bidirectional pipe 23 and discharged to the outside of the body 1. This creates a pressure difference between the inside and outside of the chamber of the cover 31. As the amount of seawater inside decreases, the pressure inside the cover 31 decreases, while the outside is still subjected to huge static pressure of seawater. This creates a downward net pressure difference and generates a huge suction force, firmly adhering the body 1 to the seabed. Since the bidirectional water pump 22 has bidirectional pumping capability, when the test is completed and the body 1 needs to be recovered, the bidirectional water pump 22 reverses its operation and injects seawater back into the sealed chamber through the bidirectional pipe 23 and the pumping channel 21, so that the pressure difference between the inside and outside of the chamber is quickly eliminated, the suction anchor 2 is released from the adsorption state, and the body 1 can be separated from the seabed. In this structure, the pumping channel 21 is set in the middle of the suction anchor 2 to ensure that the drainage path is short and efficient, while the bidirectional pipe 23 provides the channel basis for switching between forward and reverse water flow.

[0027] In a preferred embodiment, the linkage component 34 includes a housing 341, a first piston cylinder 342 and a second piston cylinder 343 fixedly mounted on the housing 341. A first piston chamber 3421 is disposed within the first piston cylinder 342, and a second piston chamber 3431 is disposed within the second piston cylinder 343. A first sliding plug 3422 is slidably connected within the first piston chamber 3421, and a second sliding plug 3432 is slidably connected within the second piston cylinder 343. A first connecting shaft 3433 is rotatably connected within the housing 341. The connecting shaft 3433 extends out of the outer shell 341 and is coaxially connected to the drive motor 321. A first connecting block 3434 and a second connecting block 3435 are fixedly connected to the first connecting shaft 3433. The first connecting shaft 3433 is coaxially fixedly connected to the screw 332. A first connecting rod 3436 is hinged to the first connecting block 3434. The first connecting rod 3436 is hinged to the first sliding plug 3422. A second connecting rod 3437 is hinged to the second connecting block 3435. The second connecting rod 3437 is hinged to the second sliding plug 3432.

[0028] Furthermore, the first piston chamber 3421 is connected to the first water inlet pipe 3441 and the first water outlet pipe 3442. The first water inlet pipe 3441 is equipped with a first check valve. The second piston chamber 3431 is connected to the second water inlet pipe 3443 and the second water outlet pipe 3444. The second water inlet pipe 3443 is equipped with a second check valve. The first water inlet pipe 3441 is connected to the pumping channel 21.

[0029] After the drive motor 321 starts, its output shaft drives the first connecting shaft 3433, which is coaxially connected to it, to rotate within the housing 341. The first connecting shaft 3433 then drives the first connecting block 3434 and the second connecting block 3435, which are fixedly connected to it, to rotate synchronously. The first connecting block 3434 converts the rotational motion into the reciprocating sealing sliding of the first sliding plug 3422 within the first piston chamber 3421 through the hinged first connecting rod 3436. At the same time, the second connecting block 3435 drives the second sliding plug 3432 to reciprocate and seal within the second piston chamber 3431 through the hinged second connecting rod 3437, thereby forming a dual-plunger alternating pumping mechanism. During the reciprocating motion of the first sliding plug 3422, when the volume of the first piston chamber 3421 increases, seawater in the sealed chamber is drawn into the first piston chamber 3421 through the first inlet pipe 3441. When the volume of the first piston chamber 3421 decreases, seawater is forcibly discharged from the outside of the machine body 1 through the first outlet pipe 3442. Similarly, when the second sliding plug 3432 reciprocates in the second piston chamber 3431, it draws in seawater through the second inlet pipe 3443 and discharges it through the second outlet pipe 3444. Since the first inlet pipe 3441 and the second inlet pipe 3443 are respectively equipped with a first one-way valve and a second one-way valve, the water flow is restricted to flow only from the sealed chamber to the piston chamber and cannot flow back. At the same time, the first outlet pipe 3442 and the second outlet pipe 3444 (usually also equipped with one-way valves) ensure that the discharged water flow can only flow outward in one direction. Thus, under the alternating reciprocating suction action of the two pistons, the seawater in the sealed chamber is continuously extracted in one direction, and the negative pressure in the chamber is continuously increased. The linkage component 34 converts the single rotary input of the drive motor 321 into the alternating pumping output of the two plungers. The displacement is continuous and the pulsation is small, which ensures the stability and efficiency of the negative pressure establishment of the suction anchor 2. Since the first water inlet pipe 3441 is connected to the water pumping channel 21, the water pumping channel 21 draws out the seawater inside the shell 31. As the amount of seawater inside decreases, the pressure inside the shell 31 drops, while the outside is still subjected to huge static pressure of seawater. This creates a downward net pressure difference, which generates a huge suction force to firmly attach the body 1 to the seabed.

[0030] The second water inlet pipe 3443 is connected to the sealed chamber (i.e., in parallel with the first water inlet pipe 3441), and both are connected to the inside of the suction anchor 2 housing 31 through the same pumping channel 21 or their respective independent branches. Its working principle and innovation are as follows: After the drive motor 321 is started, the first connecting block 3434 and the second connecting block 3435 drive the first sliding plug 3422 and the second sliding plug 3432 to reciprocate in their respective piston chambers through connecting rods. Since the first water inlet pipe 3441 and the second water inlet pipe 3443 are both connected to the sealed chamber, the two sets of plungers work together during the reciprocating suction process. When the seawater in the sealed chamber is sucked into the first piston chamber 3421 through the first water inlet pipe 3441, the second piston chamber 3431 also sucks in seawater from the same sealed chamber through the second water inlet pipe 3443. Subsequently, the two streams of seawater are forcibly discharged from the outside of the machine body 1 through the first water outlet pipe 3442 and the second water outlet pipe 3444, respectively. The alternating pumping action of the two sets of plungers superimposes, resulting in a doubling of the drainage rate of the sealed chamber compared to the single-plunger design. Crucially, when the probe encounters a hard layer during penetration, increasing the motor load, the rotational driving force of the first connecting block 3434 and the second connecting block 3435 simultaneously increases. The reciprocating amplitude and pumping frequency of the two sets of plungers increase simultaneously, and the drainage capacity of the two piston chambers doubles in the same direction with increasing load. The rate of negative pressure build-up and the final stable value within the sealed chamber are both adaptively enhanced. This design, with two inlet pipes connected in parallel to the same sealed chamber, allows the linkage component 34 to achieve a significant increase in drainage efficiency through the coordinated pumping of the two sets of plungers without requiring an additional power source. This further strengthens the positive feedback mechanism that the greater the penetration resistance, the stronger the anchoring negative pressure. Furthermore, the alternating operation of the two sets of plungers effectively reduces drainage pulsations, making the negative pressure build-up process more stable and continuous.

[0031] In a preferred embodiment, the body 1 includes a power propulsion module 4, which includes two main thrusters 41 and four vertical thrusters 42. The two main thrusters 41 are arranged at the tail of the body 1, the two vertical thrusters 42 are arranged at the front of the body 1, and the other two vertical thrusters 42 are arranged at the middle of the body 1. The two vertical thrusters 42 located at the middle of the body 1 are tilted to the left and right sides at preset angles with the vertical plane as the center line.

[0032] In this embodiment, the fuselage 1 is equipped with a six-degree-of-freedom omnidirectional drive system consisting of six thrusters. Two main thrusters 41 are symmetrically arranged at the tail of the fuselage 1, and four vertical thrusters 42 are arranged at the front and middle sides of the fuselage 1, respectively. During navigation, the two main thrusters 41 at the tail achieve horizontal movement through a differential control strategy. When rotating forward at the same speed, they propel the fuselage 1 forward; when rotating backward at the same speed, they achieve backward movement. When the two main thrusters 41 generate a speed difference, they generate a steering torque around the vertical axis, enabling left or right turns. At the same time, the four vertical thrusters 42 achieve vertical and attitude adjustments through coordinated control. The four thrusters rotate forward synchronously to provide overall upward thrust and rotate backward synchronously to provide downward thrust. The two thrusters at the front and the two thrusters in the middle work differentially (e.g., forward rotation at the front and reverse rotation at the middle) to generate a pitching torque around the lateral axis to adjust the pitch angle to adapt to the seabed slope terrain. The two thrusters on the left and the two thrusters on the right work differentially to generate a rolling torque around the longitudinal axis to keep the platform level. Crucially, the two vertical thrusters 42 located in the middle of the fuselage 1 are tilted to the left and right at preset angles (preferably 20°) with the vertical plane as the center line. When these two thrusters perform differential motion (such as the left rear thruster increasing thrust while the right rear thruster decreases thrust), the thrust vector generated by their tilted arrangement forms a lateral component in the horizontal direction. The superposition of this component generates lateral thrust, enabling the fuselage 1 to achieve lateral translation without changing its heading, thereby improving the maneuverability and control flexibility of the fuselage 1 in narrow areas or when precisely positioned.

[0033] In a preferred embodiment, a buoyancy adjustment module 5 is also included. The buoyancy adjustment module 5 includes a hydraulic pump 51, an oil bladder 52, and a pressure chamber. The pressure chamber is installed inside the body 1, the oil bladder 52 is located at the bottom of the body 1, and the hydraulic pump 51 is connected to an oil pipe. The two ends of the oil pipe are respectively connected to the oil bladder 52 and the pressure chamber.

[0034] Hydraulic oil is bidirectionally transferred between the internal pressure chamber and the external oil bladder 52 located at the bottom of the AUV 1 via hydraulic pump 51 and oil pipes to achieve displacement adjustment. When the AUV needs to dive or bottom out, hydraulic pump 51 operates in the forward direction, drawing hydraulic oil from the external oil bladder 52 back through the oil pipes and injecting it into the internal pressure chamber. The external oil bladder 52 shrinks in volume due to the reduction of oil, thereby reducing the overall displacement of the AUV and decreasing buoyancy, allowing the AUV 1 to obtain negative buoyancy and sink smoothly to the predetermined seabed position. Conversely, when the test is completed and it is time to surface for recovery, hydraulic pump 51 operates in the reverse direction, pumping hydraulic oil from the internal pressure chamber back to the external oil bladder 52 through the oil pipes. The external oil bladder 52 expands in volume due to the injection of oil, thereby increasing the overall displacement of the AUV and increasing buoyancy, allowing the AUV 1 to obtain positive buoyancy and float upward. The buoyancy adjustment module 5 precisely controls the buoyancy of the AUV by transferring oil between the pressure tank and the oil bladder 52, providing buoyancy assistance for diving to the bottom, testing operations, and surfacing for recovery. In particular, when used in conjunction with the power propulsion module 4, it can effectively reduce propulsion energy consumption and extend the underwater operation time of the AUV.

[0035] In a preferred embodiment, the bottom edge of the casing 31 is provided with a continuous annular cutting edge. The weight of the body 1 acts on the casing 31 of the suction anchor 2, and the continuous annular cutting edge at the bottom edge of the casing 31 initially contacts the seabed sediment. Under the load of gravity, this annular cutting edge, with its continuous sharp edge, cuts into the seabed sediment, severing any debris, biofilm, or microparticle obstacles, forming a complete and continuous annular cutting trajectory, allowing the bottom of the casing 31 to be evenly embedded into the sediment to a certain depth. The continuous annular structure of the cutting edge ensures that the cutting trajectory is uninterrupted, avoiding the generation of incomplete cuts or leakage channels, thereby establishing a reliable initial sealing interface between the inside of the casing 31 and the seabed. This sealing interface provides the foundation for subsequent drainage operations. When the linkage component 34 drives the suction anchor 2 to perform drainage, the seawater in the sealed chamber is pumped out, creating a negative pressure. The continuous sealing boundary formed by the annular cutting edge cutting into the sediment effectively prevents external seawater from seeping into the chamber from the edge of the casing 31, ensuring the stable establishment and maintenance of the negative pressure.

[0036] In a preferred embodiment, a cone tip resistance sensor, a sidewall friction sensor, and a pore water pressure sensor are installed at the bottom of the telescopic rod 333. The cone tip resistance sensor, located at the bottom of the probe, reflects the strength and density of the soil by measuring the end resistance encountered by the cone tip when penetrating the soil, and is a key indicator for identifying the type of strait soil layers and estimating bearing capacity. The sidewall friction sensor measures the lateral friction force between the soil and the surface of the telescopic rod 333, and is used to identify soil layer interfaces and determine soil sensitivity. The pore water pressure sensor measures the excess pore water pressure generated during penetration, and is used to assess the drainage conditions, consolidation state, and permeability of the subsea soil, providing a data basis for marine engineering geological surveys.

[0037] This application also includes a first control rudder 6 and a second control rudder 7. The first control rudder 6 is installed at the bottom of the fuselage 1, and the second control rudder 7 is installed at the tail of the fuselage 1. The first control rudder 6 is connected to the second control rudder 7. The first control rudder 6 includes a first support frame 61 and a first wing member 62. The first wing member 62 is rotatably installed on the first support frame 61. The second control rudder 7 includes a fixing plate 71 and a second wing member 72. The fixing plate 71 is fixedly installed at the tail of the fuselage 1, and the second wing member 72 is rotatably installed on the fixing plate 71. It also includes a second drive member 8, which is connected to the first wing member 62 and the second wing member 72, and is used to simultaneously drive the first wing member 62 and the second wing member 72 to move.

[0038] After the second drive unit 8 is activated, its output power is simultaneously transmitted to the first wing 62 and the second wing 72. Since the second drive unit 8 is connected to the first wing 62 of the first control rudder 6 and the second wing 72 of the second control rudder 7, and the first wing 62 is rotatably mounted on the first support frame 61 and the second wing 72 is rotatably mounted on the fixed plate 71, the second drive unit 8 can simultaneously drive the first wing 62 to rotate relative to the first support frame 61 and the second wing 72 to rotate relative to the fixed plate 71. When the second drive unit 8 moves in the forward direction, the first wing 62 and the second wing 72 deflect around their respective rotation axes to corresponding angles under the synchronous drive of the second drive unit 8, thereby changing the hydrodynamic distribution of the front part of the bottom and the middle part of the tail of the fuselage 1; when the second drive unit 8 moves in the reverse direction, the first wing 62 and the second wing 72 deflect synchronously in the opposite direction. Since the first control rudder 6 is installed at the bottom of the fuselage 1 and the second control rudder 7 is installed at the tail of the fuselage 1, and the two are mechanically linked through the second drive component 8, the movements of the first wing component 62 and the second wing component 72 are completely synchronized in time. The hydrodynamic forces generated by each wing component act on the fuselage 1, jointly adjusting the pitch attitude of the fuselage 1. When attitude adjustment is not required, the second drive component 8 maintains its current position, and the first wing component 62 and the second wing component 72 are locked at the corresponding deflection angle, providing stable hydrodynamic trim for the detector. The entire process only requires a single second drive component 8 to achieve synchronous motion control of the two sets of wing surfaces.

[0039] The reason why the first control rudder 6 at the bottom of the fuselage 1 and the second control rudder 7 at the tail are mechanically linked through a single second drive component 8 in this embodiment is to break the architectural defects of the traditional AUV attitude control system, in which the bottom fixed stabilizer and the tail elevator are independent and uncoupled. In the prior art, although the fixed stabilizer can provide a certain hydrodynamic stabilizing torque, its lift component often conflicts with the tail rudder's correction torque when adjusting pitch, forcing the tail rudder to deflect at a larger angle to overcome the interference. This not only leads to a sharp drop in propulsion efficiency and an increase in energy consumption, but also easily causes control saturation or even instability due to the attenuation of rudder effect at low speeds and near the bottom. In this embodiment, the second drive component 8 simultaneously drives the first wing component 62 and the second wing component 72 to perform reverse linkage (e.g., when the first wing component 622 pitches up, the second wing component 722 swings down, and vice versa). This transforms the bottom wing surface from a simple passive stabilizing element or interference source into a cooperative actuating surface that actively participates in attitude adjustment. The pitching moments generated by the two components are in the same direction and superimposed on each other. The required control torque can be obtained with a small control surface deflection angle, which greatly reduces additional drag and energy loss. At the same time, the mechanical linkage structure of the single second drive component 8 omits the complex electronic control synchronization algorithm, avoids the response lag caused by the timing deviation of multiple actuator actions, and can instantly generate a reverse pitching moment to correct the deviation under sudden pitch disturbances. This significantly improves the accuracy of pitch angle maintenance and anti-disturbance capability during bottom penetration operations. This solution fundamentally transforms confrontation into collaboration, not only solving the problem of low control efficiency caused by the independent functions of fixed fins and tail rudders, but also breaking through the coupling barrier of mutual constraints between stability and maneuverability in traditional architectures. It achieves efficient utilization and precise synchronization of hydrodynamics during attitude adjustment, providing an innovative control structure that combines stability, response speed and energy economy for high-precision in-situ seabed testing.

[0040] In a preferred embodiment, the first wing member 62 includes a first rotating shaft 621 and two first wing plates 622. The two first wing plates 622 are fixedly mounted on the first rotating shaft 621, and the first rotating shaft 621 is rotatably mounted on a first support frame 61. The first support frame 61 is fixedly mounted on the fuselage 1, and a first connector 623 is fixedly disposed on the first rotating shaft 621. Further, the second wing member 72 includes a second rotating shaft 721 and two second wing plates 722. The two second wing plates 722 are fixedly mounted on the second rotating shaft 721, and the second rotating shaft 721 is rotatably mounted on a fixed plate 71. A second connector 723 is fixedly disposed on the second rotating shaft 721. The second driving member 8 includes a driving part 81, a first driving rod 82, and a second driving rod 83. One end of the first driving rod 82 is connected to the first connector 623, and one end of the second driving rod 83 is connected to the second connector 723. The driving part 81 is hinged to the first driving rod 82 and the second driving rod 83.

[0041] In this embodiment, after the drive unit 81 in the second drive member 8 is activated, its output power is simultaneously transmitted to the first drive member 82 and the second drive member 83. Since the drive unit 81 is hinged to both the first drive member 82 and the second drive member 83, a single movement of the drive unit 81 can synchronously drive the first drive member 82 and the second drive member 83 to move. The other end of the first drive member 82 is connected to the first connector 623 fixedly mounted on the first rotating shaft 621, and the other end of the second drive member 83 is connected to the second connector 723 fixedly mounted on the second rotating shaft 721. When the drive unit 81 moves in the forward direction, the first drive rod 82 pushes the first connector 623, causing the first rotating shaft 621 to rotate around its own axis relative to the first support frame 61 fixedly mounted on the fuselage 1. The first rotating shaft 621 then causes the two first wing plates 622 fixedly mounted thereon to deflect synchronously. At the same time, the second drive rod 83 pushes the second connector 723, causing the second rotating shaft 721 to rotate around its own axis relative to the fixed plate 71 fixedly mounted at the tail of the fuselage 1. The second rotating shaft 721 then causes the two second wing plates 722 fixedly mounted thereon to deflect synchronously. Since both the first drive rod 82 and the second drive rod 83 are hinged to the same drive unit 81, the deflection actions of the first wing plate 622 and the second wing plate 722 are strictly synchronized in timing. When the drive unit 81 drives forward, the first connector 623 drives the first wing plate 622 to deflect in one direction (such as upward), and the second connector 723 drives the second wing plate 722 to deflect in the opposite direction (such as downward), and the two always maintain a reverse linkage relationship. When the drive unit 81 moves in the opposite direction, the first wing plate and the second wing plate 722 deflect in the opposite direction synchronously. During this process, the first rotating shaft 621 provides a common rotation axis 812 line for the two first wing plates 622, ensuring that the two first wing plates 622 deflect at the same angle; the second rotating shaft 721 provides a common rotation axis 812 line for the two second wing plates 722, ensuring that the two second wing plates 722 deflect at the same angle, thereby ensuring the symmetry of the hydrodynamic distribution on the left and right sides. The entire control process requires only one action of the drive unit 81 to simultaneously drive the front and rear airfoils through the first drive linkage 82 and the second drive linkage 83 to achieve precise linkage, without the need for complex electronic control synchronization algorithms.

[0042] Further, the first driving linkage 82 includes a first connecting rod 821, a second connecting rod 822, and a third connecting rod 823. One end of the first connecting rod 821 is hinged to the first connecting head 623, and the other end of the first connecting rod 821 is hinged to the second connecting rod 822. The free end of the second connecting rod 822 is hinged to the third connecting rod 823, and the third connecting rod 823 is hinged to the driving part 81. Further, the second driving linkage 83 includes a fourth connecting rod 831, a fifth connecting rod 832, and a sixth connecting rod 833. One end of the fourth connecting rod 831 is hinged to the driving part 81, the free end of the fourth connecting rod 831 is hinged to the fifth connecting rod 832, the free end of the fifth connecting rod 832 is hinged to the sixth connecting rod 833, and the sixth connecting rod 833 is hinged to the second connecting head 723.

[0043] In a preferred embodiment, the drive unit 81 includes a mounting plate 811, a forward and reverse motor, and a rotating shaft 812. The mounting plate 811 is fixedly installed inside the machine body 1, the forward and reverse motor is fixedly installed on the mounting plate 811, and the rotating shaft 812 is rotatably installed on the mounting plate 811. The output shaft of the forward and reverse motor is connected to the rotating shaft 812. A third connecting block 813 is fixedly installed on the rotating shaft 812, and the third connecting rod 823 and the fourth connecting rod 831 are both hinged to the third connecting block 813.

[0044] After the drive unit 81 is started, its output power is first transmitted to the third connecting rod 823 and the fourth connecting rod 831, which are hinged to the drive unit 81. The free end of the third connecting rod 823 is hinged to the second connecting rod 822, and the second connecting rod 822 is then hinged to the first connecting rod 821. The end of the first connecting rod 821 is hinged to the first connecting head 623 fixed on the first rotating shaft 621, thus forming a three-stage hinged linkage transmission chain of the first drive rod 82. At the same time, one end of the fourth connecting rod 831 is hinged to the drive unit 81, and its free end is hinged to the fifth connecting rod 832. The free end of the fifth connecting rod 832 is hinged to the sixth connecting rod 833, and the end of the sixth connecting rod 833 is hinged to the second connecting head 723 fixed on the second rotating shaft 721, thus forming a three-stage hinged linkage transmission chain of the second drive rod 83. When the drive unit 81 moves in the forward direction, it pushes the third connecting rod 823 to move. The third connecting rod 823 drives the second connecting rod 822 to swing. The second connecting rod 822 then pushes the first connecting rod 821. The first connecting rod 821 drives the first connector 623 to rotate the first rotating shaft 621 relative to the first support frame 61, causing the two first wing plates 622 fixed on the first rotating shaft 621 to deflect synchronously. At the same time, the drive unit 81 pushes the fourth connecting rod 831 to move. The fourth connecting rod 831 drives the fifth connecting rod 832 to swing. The fifth connecting rod 832 then pushes the sixth connecting rod 833. The sixth connecting rod 833 drives the second connector 723 to rotate the second rotating shaft 721 relative to the fixed plate 71, causing the two second wing plates 722 fixed on the second rotating shaft 721 to deflect synchronously. Since the third connecting rod 823 and the fourth connecting rod 831 are both hinged to the same driving part 81, and the first connecting rod 821 is hinged to the first connecting head 623 and the sixth connecting rod 833 is hinged to the second connecting head 723, the two sets of three-stage linkage mechanisms achieve strict synchronous transmission under the single action of the driving part 81. The first wing plate 622 and the second wing plate 722 always maintain a reverse linkage relationship. When the driving part 81 drives in the forward direction, the first wing plate 622 pitches up while the second wing plate 722 swings down, and the pitching moments generated by the two are in the same direction and superimposed on each other. When the driving part 81 moves in the reverse direction, the first wing plate 622 pitches down while the second wing plate 722 swings up. This three-stage articulated linkage structure transmits the rotational or push-pull motion of the drive unit 81 through the articulation of multiple links, transforming it into the deflection motion of the front and rear wing surfaces. At the same time, through the optimized arrangement of the link length and the position of the articulation point, the deflection amplitude ratio and motion direction of the front and rear wing surfaces can be flexibly adjusted to adapt to the different pitch control torque requirements of different flight states.

[0045] Furthermore, the fuselage 1 has a flattened structure. The AUV platform abandons the torpedo-shaped structure and adopts a flattened structure instead. This design has multiple advantages: First, it has a large projected area on the horizontal plane, which can significantly improve its initial stability on the seabed when combined with negative buoyancy, creating favorable conditions for subsequent suction anchor 2 attachment; second, the flattened structure is conducive to generating a ground effect when navigating near the bottom, reducing energy consumption and enhancing attitude.

[0046] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A seabed in-situ testing structure based on an AUV, characterized in that, include: The body (1), the suction anchor (2) and the probe assembly (3) are installed at the bottom of the body (1) and the probe assembly (3) is installed inside the body (1). The suction anchor (2) has a cover (31) for contacting the seabed and forming a sealed chamber. The probe assembly (3) includes a first drive member (32), a probe unit (33), and a linkage member (34). The first drive member (32) is installed inside the body (1). The probe unit (33) is connected to the output end of the first drive member (32). The linkage member (34) is connected between the suction anchor (2) and the output end of the first drive member (32). The probe unit (33) extends out of the body (1) in response to the first drive member (32) to penetrate the seabed soil, and the linkage member (34) drives the suction anchor (2) to perform a drainage action in response to the first drive member (32) to increase the negative pressure in the sealed chamber. The probe unit (33) includes a piston cylinder (331) fixedly installed inside the body (1), and the upper surface of the piston cylinder (331) is connected to the linkage component (34); A screw (332) is rotatably disposed inside the piston cylinder (331), and a telescopic rod (333) is slidably disposed at the bottom of the piston cylinder (331). The telescopic rod (333) is slidably connected to the piston cylinder (331), and a threaded hole is opened inside the telescopic rod (333). The screw (332) is threadedly connected to the threaded hole. The first driving component (32) includes a driving motor (321), which is fixedly installed inside the body (1). The output shaft of the driving motor (321) is connected to the linkage component (34). When the driving motor (321) drives the screw (332) to rotate through the linkage component (34), the telescopic rod (333) extends or retracts along the axial direction of the piston cylinder (331).

2. The AUV-based in-situ seabed testing structure according to claim 1, characterized in that: The suction anchor (2) has a water pumping channel (21) in the middle, and a bidirectional pipe (23) is connected to the end of the water pumping channel (21). A bidirectional water pump (22) is connected to the end of the bidirectional pipe (23), and the bidirectional water pump (22) is fixedly installed inside the body (1).

3. The AUV-based in-situ seabed testing structure according to claim 2, characterized in that: The linkage component (34) includes a housing (341), a first piston cylinder (342) and a second piston cylinder (343) fixedly disposed on the housing (341). The first piston cylinder (342) is provided with a first piston chamber (3421), and the second piston cylinder (343) is provided with a second piston chamber (3431). The first piston chamber (3421) is slidably connected with a first sliding plug (3422), and the second piston cylinder (343) is slidably connected with a second sliding plug (3432). A first connecting shaft (3433) is rotatably connected inside the outer casing (341). The first connecting shaft (3433) extends out of the outer casing (341) and is coaxially connected to the drive motor (321). A first connecting block (3434) and a second connecting block (3435) are fixedly connected to the first connecting shaft (3433). The first connecting shaft (3433) is coaxially fixedly connected to the screw (332). A first connecting rod (3436) is hinged to the first connecting block (3434), and the first connecting rod (3436) is hinged to the first sliding plug (3422). A second connecting rod (3437) is hinged to the second connecting block (3435), and the second connecting rod (3437) is hinged to the second sliding plug (3432).

4. The AUV-based in-situ seabed testing structure according to claim 3, characterized in that: The first piston chamber (3421) is connected to the first inlet pipe (3441) and the first outlet pipe (3442). The first inlet pipe (3441) is equipped with a first check valve. The second piston chamber (3431) is connected to the second inlet pipe (3443) and the second outlet pipe (3444). The second inlet pipe (3443) is equipped with a second check valve. The first inlet pipe (3441) is connected to the pumping channel (21).

5. The AUV-based in-situ seabed testing structure according to claim 4, characterized in that: The body (1) includes a power propulsion module (4), which includes two main thrusters (41) and four vertical thrusters (42). The two main thrusters (41) are arranged at the tail of the body (1), while the two vertical thrusters (42) are arranged at the front of the body (1) and the other two vertical thrusters (42) are arranged in the middle of the body (1). The two vertical thrusters (42) located in the middle of the body (1) are tilted to the left and right sides at preset angles with the vertical plane as the center line.

6. The AUV-based in-situ seabed testing structure according to claim 5, characterized in that: It also includes a buoyancy adjustment module (5), which includes a hydraulic pump (51), an oil bladder (52) and a pressure chamber. The pressure chamber is installed inside the body (1), the oil bladder (52) is located at the bottom of the body (1), the hydraulic pump (51) is connected to an oil pipe, and the two ends of the oil pipe are respectively connected to the oil bladder (52) and the pressure chamber.

7. The AUV-based in-situ seabed testing structure according to claim 1, characterized in that: The bottom edge of the cover (31) is provided with a continuous circular cutting edge.

8. The AUV-based in-situ seabed testing structure according to claim 1, characterized in that: The bottom of the telescopic rod (333) is equipped with a cone tip resistance sensor, a side wall friction sensor, and a pore water pressure sensor.

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