Underwater robot with splicing function and method thereof

Abstract

The invention discloses an underwater robot with a splicing function and a method thereof, and belongs to the field of underwater robots, the underwater robot comprises a waterproof shell, a sensing module, a main control module, a power supply module and a rotary splicing module; the sensing module is used for environment sensing, the main control module is used for decision control, the power supply module provides energy support, the rotary splicing module is a core module of the robot, a rotary telescopic mechanism comprising a rotary shaft telescopic arm and a limiting rotor is creatively provided, and the rotary telescopic mechanism can be matched with limiting grooves in waterproof shells of other single robots. And splicing of the underwater robot is realized. According to the scheme of combining the underwater robot through the rotary splicing mechanism, independent operation or group operation can be selected according to the use scene, the combination shape can be switched during group operation to meet the task requirement, and the group task which cannot be completed by a traditional individual robot is achieved; therefore, the adaptability and execution capability of the underwater robot to complex tasks and environments are improved.

Description

Technical Field

[0001] This invention belongs to the field of underwater robots, specifically relating to an underwater robot with splicing function and its method. Technical Background

[0002] Underwater robots are robots that can work independently in underwater environments. They are widely used in fields such as marine resource exploration, environmental monitoring, and marine space exploration. They can replace or assist humans in entering dangerous or inaccessible underwater environments to perform tasks, greatly improving the efficiency and safety of underwater operations.

[0003] Existing underwater robots are typically designed and deployed as individual units. The operational capabilities of these individual robots are limited by their inherent properties, such as size, payload capacity, energy reserves, and sensor configuration. Therefore, when faced with large-scale or highly complex group tasks, a single underwater robot often struggles to complete the task independently. Even robots with assembly capabilities often fail to form a durable and reliable collaborative system due to unstable connections.

[0004] Therefore, there is an urgent need for an underwater robot that can work independently or be stably assembled to complete group tasks according to mission requirements, to overcome the limitations of single underwater robots and improve the adaptability and execution capabilities of underwater robots in the face of complex tasks and environments. Summary of the Invention

[0005] To address the problems in the prior art, this invention proposes an underwater robot with splicing function and its method. By using a rotation limiting device, the underwater robot is equipped with splicing function, which facilitates the swarm operation of the robots.

[0006] The technical solution adopted in this invention is as follows:

[0007] This invention provides an underwater robot with splicing function, including a waterproof shell, a sensing module installed inside and outside the waterproof shell, a main control module, a power supply module, and a rotating splicing module; the sensing module is used for environmental perception, the main control module performs decision control, the power supply module provides energy support, and the rotating splicing module realizes the mechanical splicing between robots;

[0008] The waterproof outer shell is hexagonal prism-shaped, with a guide protrusion with stepped through holes on the front side plate. The other five side plates, excluding the front side plate, are provided with limiting grooves. The limiting grooves include conical holes that taper inward and grooves that connect to the inside of the conical holes. The grooves and the conical holes form an annular platform at their connection.

[0009] The rotating splicing module includes a servo motor, a hollow cup motor bracket, a hollow cup motor, a rotating telescopic arm, and a limiting rotor. The servo motor is fixed in the servo motor recess inside the waterproof housing. The hollow cup motor bracket is connected to the servo motor drive shaft through an eccentric transmission mechanism. The hollow cup motor is installed inside the hollow cup motor bracket and has a pressure sensor at the bottom. The limiting rotor is fixed to the output shaft of the hollow cup motor. The rotating telescopic arm is composed of an inner telescopic arm and an outer telescopic arm hinged through a free end hole. The inner telescopic arm and the outer telescopic arm are respectively hinged to the hollow cup motor bracket and the limiting rotor through fixed end holes.

[0010] The servo motor drives the hollow cup motor bracket to move linearly along the axis of the stepped through hole of the guide protrusion. When the servo motor is reset, the limiting rotor and the stepped through hole of the guide protrusion form a sealed fit. When the servo motor is working, the extension stroke of the limiting rotor meets the docking distance requirements of the two robots. The hollow cup motor drives the limiting rotor to rotate and drives the rotating telescopic arm to unfold or close. When unfolded, the free end of the rotating telescopic arm is inserted into the inner side of the annular platform of the limiting groove of another underwater robot to achieve mechanical splicing.

[0011] Preferably, the inner telescopic arm and the outer telescopic arm of the rotating telescopic arm are each composed of three arc-shaped blocks, and each arc-shaped block is provided with a fixed end hole and a free end hole at both ends.

[0012] Preferably, the top of the hollow cup motor bracket is provided with three arc-shaped bracket limiting protrusions. When the rotating telescopic arm is extended to the maximum angle, the arc-shaped block of the inner telescopic arm contacts the bracket limiting protrusions to achieve mechanical locking.

[0013] Preferably, the limiting rotor has a spherical crown-shaped structure with a flat inner side and a spherical crown curved outer side, and three recessed mounting holes for connecting the outer telescopic arm are evenly distributed around the circumference. The diameter of the limiting rotor is smaller than the minimum conical hole diameter of the limiting groove and not smaller than the maximum diameter of the stepped through hole of the guide protrusion.

[0014] Preferably, the taper of the outer wall of the guide protrusion matches the taper of the tapered hole of the limiting groove, and the stepped through hole inside the guide protrusion includes a larger hole on the outside and a smaller hole on the inside. The diameter of the larger hole matches the diameter of the limiting rotor, and the diameter of the smaller hole matches the diameter of the hollow cup motor.

[0015] Preferably, a waterproof ring is provided at the stepped through hole.

[0016] Preferably, the sensing module includes a visual sensing unit mounted on the front panel of the waterproof housing and an inertial measurement unit located inside the waterproof housing.

[0017] Preferably, it also includes a drive module, which includes several horizontal drive units and vertical drive units installed on the bottom surface of the waterproof shell. Each drive unit is driven by a motor connected to the main control module, and the movement speed and posture of the underwater robot are controlled by adjusting the motor.

[0018] Preferably, the main control module includes heat sinks, electronic speed controllers, voltage regulator circuit boards, and main control boards stacked from bottom to top. The voltage regulator circuit board converts the voltage of the power supply module into the operating voltage required by each module. The main control board receives environmental data collected by the sensing module and generates motion control signals and splicing control signals. The splicing control signals are sent to the servo motors and coreless motors, and the motion control signals are sent to the electronic speed controller to control the movement speed and posture of the underwater robot.

[0019] This invention also provides a method for assembling an underwater robot with splicing capabilities, comprising:

[0020] Step 1: The current underwater robot establishes a communication connection with the target underwater robot, exchanges relative position and body attitude information, and transmits the information to the main control module;

[0021] Step 2: The main control module generates motion control signals based on relative position and body posture information, driving the robots to move closer to each other and adjust their postures until the current robot's limit rotor aligns with the target robot's limit slot.

[0022] Step 3: The main control module of the underwater robot sends a splicing command. The servo motor controls the rotating splicing module to extend the waterproof shell. When the pressure sensor value reaches the preset contact force threshold, the hollow cup motor drives the limit rotor to rotate in the forward direction. The outer telescopic arm drives the inner telescopic arm to unfold until the inner telescopic arm rotates to contact the limit protrusion and locks. At this time, the free end of the rotating telescopic arm is inserted into the inner side of the annular platform of the target robot's limit groove, completing the mechanical splicing.

[0023] Step 4: After the group operation is completed, the main control module of the current underwater robot sends a separation command. The hollow cup motor drives the limit rotor to rotate in the opposite direction, and the outer telescopic arm drives the inner telescopic arm to retract until the rotating telescopic arm is completely retracted between the limit rotor and the hollow cup motor bracket. The servo motor drives the rotating splicing module to retract, and the limit rotor and the through hole of the guide protrusion restore the sealed engagement state.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) This invention provides an underwater robot with splicing function, which can be combined by splicing mechanism on the basis of completing individual tasks, and switch different combination shapes according to the usage scenario to adapt to task requirements, thereby realizing group tasks that traditional individual robots cannot complete, and improving the adaptability and execution capability of underwater robot groups in the face of complex tasks and environments.

[0026] (2) The present invention uses a telescopic device and a rotation limiting device to realize the splicing function. Compared with the robot splicing method based on magnetic force, the splicing method proposed in the present invention is more stable and can better adapt to the complex and ever-changing underwater environment. Compared with the robot splicing method based on buckles, the splicing method proposed in the present invention is faster. Compared with other robot splicing methods based on mechanical limiting, the splicing method proposed in the present invention has higher robustness and can better adapt to the undulating underwater environment. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the external structure of an underwater robot with splicing capabilities;

[0028] Figure 2 This is a schematic diagram of the internal structure of an underwater robot with splicing capabilities;

[0029] Figure 3 This is a schematic diagram of the rotating and telescopic mechanism of an underwater robot with splicing capabilities;

[0030] Figure 4 This is a schematic diagram of the hollow cup motor support structure of an underwater robot with splicing capabilities;

[0031] Figure 5 This is a schematic diagram of the rotating telescopic unit of an underwater robot with splicing capabilities in its extended state.

[0032] Figure 6 This is a schematic diagram illustrating the splicing process between individual underwater robot units with splicing capabilities;

[0033] In the diagram, 101-top sealing cover, 102-waterproof shell, 103-limiting groove, 1031-ring platform, 104-guide protrusion, 105-servo motor sinking groove, 201-battery, 202-battery support frame, 301-visual perception unit, 302-inertial measurement unit, 401-main control board, 402-voltage stabilizing circuit board, 403-electronic speed controller, 404-heat sink, 501-horizontal drive motor, 502-vertical drive motor, 503-motor support frame, 6-rotating telescopic mechanism, 601-servo motor, 602-hollow cup motor bracket, 6021-bracket limiting protrusion, 603-hollow cup motor, 604-rotating telescopic arm, 6041-telescopic arm fixed end hole, 6042-telescopic arm free end hole, 605-limiting rotor. Detailed Implementation

[0034] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0035] like Figure 1 As shown, this invention provides an underwater robot with a splicing function. The underwater robot's shell is hexagonal prism-shaped and consists of a top sealing cover 101 and a waterproof outer shell 102, both made of ABS material using 3D printing. On the front side plate of the waterproof outer shell 102, there is a boss structure with stepped through holes, serving as a guide protrusion 104. The stepped through holes include a larger outer hole and a smaller inner hole, and the through holes are waterproofed using waterproof rings. The remaining five side plates of the waterproof outer shell 102 are each provided with a limiting groove 103. The limiting groove 103 is formed by connecting an inwardly tapered conical hole and a groove, with the groove being a cylindrical groove. The smaller end diameter of the conical hole is smaller than the opening diameter of the groove, creating a ring-shaped platform 1031 at the connection point. The limiting groove 103 provides a guiding and limiting function during the underwater robot's splicing operation. A servo motor sinking groove 105 is also provided on the inner bottom of the waterproof outer shell 102.

[0036] In one specific embodiment of the present invention, the top of the side panels of the waterproof housing 102 are provided with raised waterproof grooves, and the bottom of the top sealing cover 101 is provided with a groove. A silicone waterproof strip is provided in the groove, which can fit with the waterproof groove on the side panel to achieve a waterproof effect.

[0037] like Figure 1 and Figure 2 The figures shown are schematic diagrams of the internal and external structures of the underwater robot proposed in this invention. This invention integrates five major modules inside and outside the waterproof shell 102: power supply module, sensing module, main control module, drive module, and rotation splicing module.

[0038] The power supply module supplies power to the entire underwater robot and includes a battery 201, a battery support frame 202, and a waterproof switch (not shown in the figure). The battery support frame 202 is fixed to the rear panel of the waterproof shell 102 to support and fix the battery 201. The battery 201 is preferably a lithium battery, which is fixed to the battery support frame 202 with straps and supplies power to the entire underwater robot through the main control module. A waterproof switch is provided on the outside of the waterproof shell 102 to control the connection and disconnection between the battery and the main control module. The sensing module is used to acquire the relative position of nearby underwater robots and collect the body attitude information of the underwater robots, and transmit the collected information to the main control module. It includes a visual sensing unit 301 and an inertial measurement unit 302. The visual sensing unit 301 consists of two RGB wide-angle cameras, which are fixed to the upper part of the front panel of the waterproof shell 102. It is responsible for collecting images and distance data of nearby underwater robots and their surrounding environment and transmitting the data to the main control module. Specifically, the two cameras can acquire image information within a 120° range in front of the robot, and can also identify markings on nearby robots to obtain their identity information. The data from the two cameras is then fused to obtain distance information within a 60° range in front. The inertial measurement unit 202 is installed in a device mounting slot (not shown in the figure) inside the waterproof housing's base plate, responsible for sensing the underwater robot's own attitude and transmitting the attitude data to the main control module. Furthermore, the sensing module can also be equipped with a communication unit for data exchange with other underwater robots. Connecting the communication unit's serial or Ethernet interface to the main control module supports real-time data transmission; this part can utilize the existing communication functions of the underwater robot.

[0039] In one specific embodiment of the present invention, the inertial measurement unit 302 can be selected as needed for installation or not. If the inertial measurement unit is not installed, the movement of the underwater robot can be controlled by remote control.

[0040] The main control module manages the data provided by each module, makes decisions, and sends control signals to the drive module. It includes a main control board 401, a voltage regulator circuit board 402, an electronic speed controller 403, and a heat sink 404. The heat sink 404, made of aluminum alloy and manufactured using CNC technology, is embedded in the center of the waterproof housing 102 base plate and serves to efficiently dissipate heat from the main control module. The electronic speed controller 403, voltage regulator circuit board 402, and main control board 401 are sequentially mounted above the heat sink 404. The waterproof housing 102 base plate, voltage regulator circuit board 402, and main control board 401 are fixedly supported by copper pillars. The voltage regulator circuit board 402 and electronic speed controller 403 convert the voltage provided by the power supply module into a working voltage that matches the other modules. The main control board 401 processes the data acquired by the sensing module, performs motion planning and control, and sends control signals to the drive module.

[0041] The drive module receives control signals from the main control module and changes the underwater robot's speed and posture, providing driving force. It includes two horizontal drive motors 501, four vertical drive motors 502, and four motor support frames 503. The motor support frames 503 are installed inside the waterproof housing 102 to fix the vertical drive motors 502, whose drive ends are connected to an electronic speed controller 403. The two horizontal drive motors 501 are integrated and installed on the outside of the waterproof housing 102's base plate. Their drive ends are connected to the electronic speed controller 403, employing differential model control to change the underwater robot's direction and speed within the motion plane. Working in conjunction with the four vertical drive motors 502, they allow for flexible adjustment of the underwater robot's posture.

[0042] The main structure of the rotating splicing module is a rotating telescopic mechanism 6, which can cooperate with the limiting groove 103 and the guide protrusion 104 on the waterproof shell 102 to complete the splicing operation with the nearby underwater robot.

[0043] like Figure 3 The diagram shows the structure of the rotating and telescopic mechanism of the underwater robot, which includes a servo motor 601, a hollow cup motor bracket 602, a hollow cup motor 603, a rotating and telescopic arm 604, and a limiting rotor 605. The hollow cup motor bracket 602, the rotating and telescopic arm 604, and the limiting rotor 605 are all made of ABS material by 3D printing.

[0044] The servo motor 601 is fixed in the servo motor sink 105 and is used to receive control signals and output rotational motion. The drive shaft of the servo motor 601 faces upward. The drive shaft of the servo motor 601 is connected to the hollow cup motor bracket 602 through an eccentric transmission mechanism. The eccentric transmission mechanism includes an eccentric wheel and a connecting rod. The drive shaft of the servo motor 601 is fixed to the eccentric wheel and can drive the eccentric wheel to rotate in the horizontal plane. One end of the connecting rod is hinged to the eccentric wheel, and the other end is hinged to the end of the hollow cup motor bracket 602. Under the drive of the eccentric transmission mechanism, the hollow cup motor bracket 602 can move linearly, that is, the rotational motion of the servo motor 601 is finally converted into the linear motion of the hollow cup motor bracket 602.

[0045] A hollow cup motor 603 is installed inside a hollow cup motor bracket 602. A pressure sensor is located at the bottom of the hollow cup motor 603. The axial direction of the hollow cup motor 603 has a movement margin. The "D"-shaped output shaft of the hollow cup motor 603 is fixed to the inner end face of the limiting rotor 605, allowing the hollow cup motor 603 to drive the limiting rotor 605 to rotate. The rotating telescopic arm 604 consists of an inner telescopic arm and an outer telescopic arm. Each inner and outer telescopic arm includes three arc-shaped blocks. Each arc-shaped block has a telescopic arm fixed end hole 6041 at one end and a telescopic arm free end hole 6042 at the other end. The telescopic arm fixed end hole 6041 of the outer arc-shaped block is hinged to the three mounting holes on the limiting rotor 605 via locking screws. The telescopic arm fixed end hole 6041 of the inner arc-shaped block is hinged to the hollow cup motor bracket. Figure 4 As shown, the top of the hollow cup motor bracket is provided with a mounting plate. The mounting plate has three mounting holes and three arc-shaped bracket limiting protrusions 6021. The curvature of the bracket limiting protrusions matches the curvature of the arc-shaped block. During installation, the telescopic arm fixed end hole 6041 of the inner arc-shaped block is hinged to the three mounting holes on the mounting plate by locking screws. The inner arc-shaped block and the telescopic arm free end hole 6042 of the outer arc-shaped block are also hinged by locking screws. Therefore, a rotating pair is formed at the telescopic arm fixed end hole 6041 and the telescopic arm free end hole 6042 of each arc-shaped block, which can rotate around the locking screw.

[0046] like Figure 5 As shown in (a), when the limiting rotor 605 rotates in the forward direction, it can drive the three arc-shaped blocks in the outer telescopic arm to expand outward synchronously and equally, thereby driving the inner telescopic arm to expand outward, that is, the entire rotating telescopic arm 604 rotates and expands, and the maximum diameter of the rotational expansion is not less than the inner diameter of the annular platform 1031. Because the hollow cup motor bracket is provided with a bracket limiting protrusion 6021, as... Figure 5 As shown in (b), during the process of the outer telescopic arm unfolding and driving the inner telescopic arm to unfold, it locks when it touches the bracket limit protrusion 6021. Similarly, when the limit rotor 605 rotates in the opposite direction, it drives the entire rotating telescopic arm 604 to rotate and close between the hollow cup motor bracket 602 and the limit rotor 605.

[0047] In one specific embodiment of the present invention, the limiting rotor 605 is an integral spherical crown structure with circumferentially distributed recessed mounting holes. Its inner side is a plane, and its outer side is a spherical crown curved surface. The recessed mounting holes serve as the mounting fulcrum of the rotary pair. The thickness of the limiting rotor 605 does not exceed the groove depth in the limiting groove 103. The diameter of the limiting rotor is smaller than the diameter of the small end of the conical hole of the limiting groove 103 but not smaller than the larger hole diameter of the guide protrusion 104 of the robot housing. The diameter of the hollow cup motor 603 matches the smaller hole diameter of the guide protrusion 104, and the motor can extend from the smaller hole while ensuring sealing. The limiting rotor 605 moves linearly under the drive of the servo motor 601. When the servo motor 601 resets, the limiting rotor 605 abuts against the guide protrusion 104 of the robot housing to form a sealing structure. When the servo motor 601 drives the limiting rotor 605 to extend, the extension amount meets the splicing requirements of two robot units.

[0048] Figure 6 The diagram illustrates the principle of rotating and joining two underwater robot units. The joining process includes the docking and separation of the underwater robots. For ease of description, the robot unit controlling the rotation and extension mechanism is referred to as the current robot, and the other robot unit is referred to as the target robot. The underwater robot docking process is as follows:

[0049] The current robot communicates with the target robot, exchanging body posture information collected by their respective sensing modules. The two robots are controlled to gradually approach and align with the current robot's limiting rotor and the target robot's limiting slot 103 to be joined. The current robot's servo motor 601 pushes the hollow cup motor bracket 602 through a linkage, extending it out of the guide protrusion 104 on the waterproof housing 102 and moving linearly along the through-hole axis of the guide protrusion 104. A pressure sensor is installed at the bottom of the hollow cup motor 603. When the hollow cup motor bracket 602 is pushed out to the point where the pressure reaches a threshold, the hollow cup motor 603 drives the limiting rotor 605 to rotate forward. The limiting rotor 605 causes the outer telescopic arm to unfold, which in turn causes the inner telescopic arm to unfold. When the inner telescopic arm rotates to the bracket limiting protrusion 6021 at the top of the hollow cup motor bracket 602, it locks in place. At this point, the free end of the current robot's rotating telescopic arm 604 is locked inside the annular platform 1031 of the target robot's limiting slot 103, thus achieving the joining.

[0050] The underwater robot separation process is as follows:

[0051] The robot's hollow cup motor 603 drives the limiting rotor 605 to rotate in the opposite direction, causing the rotating telescopic arm 604 to retract to between the limiting rotor 605 and the hollow cup motor bracket 602. The servo motor 601 drives the hollow cup motor bracket 602 to retract back into the waterproof housing 102 through the connecting rod. At this time, the limiting rotor 605 is reset and keeps sealed with the through hole of the guide protrusion 104.

[0052] In addition, the inner surface of the limiting rotor 605 may be provided with a groove to avoid axial deviation due to the thickness of the locking nut during the unfolding / closing of the rotating telescopic arm 604.

[0053] Based on the above, the present invention also provides a method for assembling an underwater robot with splicing function, the specific steps of which are as follows:

[0054] Step 1. The underwater robot (current robot) communicates with the target underwater robot (target robot) to be spliced, and each obtains the relative position and body posture information of the other robot. The collected information is then transmitted to the main control module. Specifically, the visual perception unit obtains images and distance data of nearby underwater robots and the surrounding environment, and the inertial measurement unit perceives its own posture.

[0055] Step 2. The main control module analyzes the data information obtained by the perception module, solves the control signal of the robot's motion state based on the body posture information, and sends the control signal to the drive module for body posture control; based on the relative position of nearby underwater robots, it solves the control signal for alignment with nearby robots, and sends the control signal to the drive module to realize the underwater robots approaching and aligning with each other until the current robot's limiting rotor 605 is aligned with the target robot's limiting slot 103; here, when performing body posture control, the drive module receives the control signal from the main control module, drives the underwater robot forward through the horizontal drive motor, and drives the underwater robot to adjust its posture through the vertical drive motor;

[0056] Step 3. The main control module sends a control signal to control the rotating splicing module to extend the waterproof shell through the servo motor 601. When the pressure sensor value reaches the threshold, the hollow cup motor drives the limiting rotor 605 to rotate in the forward direction. The limiting rotor 605 drives the outer telescopic arm to unfold. When the outer telescopic arm unfolds, it drives the inner telescopic arm to unfold. When the inner telescopic arm rotates to the bracket limiting protrusion 6021 on the hollow cup motor bracket 602, it locks. At this time, the free end of the telescopic arm is stuck inside the ring platform 1031 to complete the limiting. Thus, the underwater robot can be spliced ​​with other underwater robots.

[0057] Step 4. After the group operation is completed, the main control module of the current robot sends a control signal. The hollow cup motor drives the limit rotor 605 to rotate in the opposite direction. The limit rotor 605 drives the outer telescopic arm to close. When the outer telescopic arm closes, it drives the inner telescopic arm to close. The rotating telescopic arm 604 retracts to between the limit rotor 605 and the hollow cup motor bracket 602. Then, the servo motor 601 controls the rotating splicing module to retract and return to its original position, maintaining a seal with the through hole of the guide protrusion 104.

[0058] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An underwater robot with splicing function, characterized in that, It includes a waterproof shell (102), a sensing module, a main control module, a power supply module, and a rotating splicing module installed inside and outside the waterproof shell; the sensing module is used for environmental perception, the main control module performs decision control, the power supply module provides energy support, and the rotating splicing module realizes mechanical splicing between robots; The waterproof outer shell is hexagonal prism-shaped, with a guide protrusion (104) with stepped through holes on the front side plate. The other five side plates are provided with limiting grooves (103). The limiting groove includes an inwardly tapered hole and a groove connected to the inside of the tapered hole. The groove and the tapered hole form an annular platform (1031). The rotating splicing module includes a servo motor (601), a hollow cup motor bracket (602), a hollow cup motor (603), a rotating telescopic arm (604), and a limiting rotor (605). The servo motor is fixed in the servo motor sink groove inside the waterproof housing. The hollow cup motor bracket is connected to the servo motor drive shaft through an eccentric transmission mechanism. The hollow cup motor is installed inside the hollow cup motor bracket and has a pressure sensor at the bottom. The limiting rotor is fixed to the output shaft of the hollow cup motor. The rotating telescopic arm is composed of an inner telescopic arm and an outer telescopic arm hinged through a free end hole. The inner telescopic arm and the outer telescopic arm are respectively hinged to the hollow cup motor bracket and the limiting rotor through fixed end holes. The servo motor drives the hollow cup motor bracket to move linearly along the axis of the stepped through hole of the guide protrusion. When the servo motor is reset, the limiting rotor and the stepped through hole of the guide protrusion form a sealed fit. When the servo motor is working, the extension stroke of the limiting rotor meets the docking distance requirements of the two robots. The hollow cup motor drives the limiting rotor to rotate and drives the rotating telescopic arm to unfold or close. When unfolded, the free end of the rotating telescopic arm is inserted into the inner side of the annular platform of the limiting groove of another underwater robot to achieve mechanical splicing.

2. The underwater robot with splicing function according to claim 1, characterized in that, The inner and outer telescopic arms of the rotating telescopic arm are each composed of three arc-shaped blocks, and each arc-shaped block has a fixed end hole and a free end hole at both ends.

3. The underwater robot with splicing function according to claim 2, characterized in that, The hollow cup motor bracket has three arc-shaped bracket limiting protrusions (6021) at its top. When the rotating telescopic arm is extended to its maximum angle, the arc-shaped block of the inner telescopic arm contacts the bracket limiting protrusions to achieve mechanical locking.

4. The underwater robot with splicing function according to claim 2, characterized in that, The limiting rotor is a spherical crown-shaped structure with a flat inner side and a spherical crown curved outer side. It has three sinking mounting holes evenly distributed around the circumference for connecting the outer telescopic arm. The diameter of the limiting rotor is smaller than the minimum conical hole diameter of the limiting groove and not smaller than the maximum diameter of the stepped through hole of the guide protrusion (104).

5. The underwater robot with splicing function according to claim 1, characterized in that, The taper of the outer wall of the guide protrusion (104) matches the taper of the tapered hole of the limiting groove (103). The stepped through hole inside the guide protrusion (104) includes a larger hole on the outside and a smaller hole on the inside. The diameter of the larger hole matches the diameter of the limiting rotor, and the diameter of the smaller hole matches the diameter of the hollow cup motor.

6. The underwater robot with splicing function according to claim 1, characterized in that, A waterproof ring is provided at the stepped through hole.

7. The underwater robot with splicing function according to claim 1, characterized in that, The sensing module includes a visual sensing unit (301) mounted on the front panel of the waterproof housing and an inertial measurement unit (302) located inside the waterproof housing.

8. The underwater robot with splicing function according to claim 1, characterized in that, It also includes a drive module, which comprises several horizontal drive units and vertical drive units mounted on the bottom surface of the waterproof shell. Each drive unit is driven by a motor connected to the main control module, and the movement speed and posture of the underwater robot are controlled by adjusting the motor.

9. The underwater robot with splicing function according to claim 1, characterized in that, The main control module includes heat sinks, electronic speed controllers, voltage regulator circuit boards, and main control boards stacked from bottom to top. The voltage regulator circuit board converts the voltage of the power supply module into the operating voltage required by each module. The main control board receives environmental data collected by the sensing module and generates motion control signals and splicing control signals. The splicing control signals are sent to the servo motors and coreless motors, and the motion control signals are sent to the electronic speed controller to control the underwater robot's speed and posture.

10. A splicing method for an underwater robot with splicing function as described in claim 1, characterized in that, include: Step 1: The current underwater robot establishes a communication connection with the target underwater robot, exchanges relative position and body attitude information, and transmits the information to the main control module; Step 2: The main control module generates motion control signals based on relative position and body posture information, driving the robots to move closer to each other and adjust their postures until the current robot's limit rotor aligns with the target robot's limit slot. Step 3: The main control module of the underwater robot sends a splicing command. The servo motor controls the rotating splicing module to extend the waterproof shell. When the pressure sensor value reaches the preset contact force threshold, the hollow cup motor drives the limit rotor to rotate in the forward direction. The outer telescopic arm drives the inner telescopic arm to unfold until the inner telescopic arm rotates to contact the limit protrusion and locks. At this time, the free end of the rotating telescopic arm is inserted into the inner side of the annular platform of the target robot's limit groove, completing the mechanical splicing. Step 4: After the group operation is completed, the main control module of the current underwater robot sends a separation command. The hollow cup motor drives the limit rotor to rotate in the opposite direction, and the outer telescopic arm drives the inner telescopic arm to retract until the rotating telescopic arm is completely retracted between the limit rotor and the hollow cup motor bracket. The servo motor drives the rotating splicing module to retract, and the limit rotor and the through hole of the guide protrusion restore the sealed engagement state.

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