Docking mechanism and method for Stewart parallel platform driving type modular snake-shaped robot

Abstract

The invention provides a docking mechanism and method for a Stewart parallel platform driving type modular snake-shaped robot. The docking mechanism comprises a static platform assembly, a Stewart parallel driving unit and a docking execution unit. The static platform assembly is used for being fixed to the tail end of the modular snakelike robot. The two ends of six electric telescopic connecting rods of the Stewart parallel driving unit are connected with the static platform assembly and the movable platform assembly through hooke joints correspondingly, and a six-degree-of-freedom movement mechanism is formed. A movable side butt-joint assembly of the butt-joint execution unit is rotatably installed on the movable platform assembly, and a static side butt-joint seat of the butt-joint execution unit is used for being fixed to the front end of the modular snakelike robot to be in butt joint. According to the invention, by realizing high-precision docking alignment, the connection rigidity is enhanced, the flexible attitude adjustment capability is provided, and the docking reliability is improved, so that the technical problems of limited task adaptability, difficult maintenance and poor function expansibility caused by fixed structure and incapability of reconstruction of the modular snake-shaped robot in the face of complex tasks are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of modular robot connection mechanism, in particular to a docking mechanism and method of a Stewart parallel platform driven modular snake robot. BACKGROUND

[0002] A snake robot is a kind of continuum robot composed of multiple modular units, which has high degrees of freedom, small volume, various motion capabilities that traditional robots do not have, and can reach positions that other robots cannot reach. Snake robots have wide application prospects in narrow space exploration, post-disaster search and rescue, pipeline inspection, military reconnaissance and other fields due to their multi-joint, high degrees of freedom and strong environmental adaptability. Snake robots can change their shape to move in complex terrain environments, but traditional integrated snake robots have certain motion flexibility, but when facing complex tasks, they often have limited task adaptability, maintenance difficulties and poor functional expansion due to fixed structure and inability to reconfigure.

[0003] Modular robots can connect and disconnect between modules through standardized interfaces, dynamically reconfigure according to task requirements, and significantly improve system flexibility and robustness. However, the docking mechanisms of existing modular snake robots mostly use simple mechanical pins, electromagnetic adsorption or buckle connection methods, which have low docking precision, insufficient connection stiffness, weak attitude adjustment capability, and inability to adjust the overall pose after docking, limiting their collaborative work capability in dynamic environments.

[0004] When performing complex tasks such as crossing rugged mountainous terrain, crossing gullies longer than the length of the snake robot, etc., it is impossible to complete the search task successfully by relying solely on itself. Therefore, a reconfigurable modular snake robot is introduced, which can selectively dock and reconfigure with other snake robot modules according to the terrain and environmental characteristics of the scene when a single robot cannot complete the task, thereby forming a snake robot with more joints and stronger motion capabilities.

[0005] Therefore, the present application proposes a modular snake robot docking mechanism based on a Stewart parallel platform, aiming to achieve high-precision, high-stiffness, multi-degree-of-freedom autonomous docking and attitude collaborative control, and improve the environmental adaptability and task execution capability of the modular snake robot. SUMMARY

[0006] This invention provides a docking mechanism and method for a Stewart parallel platform-driven modular snake robot, which achieves high-precision docking alignment, enhances connection rigidity, provides flexible attitude adjustment capability, and improves docking reliability. This solves the technical problems of limited task adaptability, difficult maintenance, and poor functional expandability caused by fixed structure and inability to reconfigure when facing complex tasks.

[0007] This invention provides a docking mechanism for a Stewart parallel platform-driven modular snake robot, comprising:

[0008] A static platform component for attaching to the end effector of a modular snake robot; The Stewart parallel drive unit includes six electric telescopic links and corresponding lower and upper Hooke hinges. The two ends of each electric telescopic link are connected to the static platform assembly through the lower Hooke hinge and to the dynamic platform assembly through the upper Hooke hinge, forming a six-degree-of-freedom motion mechanism. The docking execution unit includes a moving-side docking assembly and a stationary-side docking seat. The moving-side docking assembly is rotatably mounted on the moving platform assembly, and the stationary-side docking seat is used to fix the front end of the modular snake robot to be docked.

[0009] In one embodiment of the present invention, the static platform assembly includes a static platform base, which is a hexagonal plate structure, and six Hooke hinge mounting seats are evenly arranged on its edge for connecting to an electric telescopic linkage via a lower Hooke hinge.

[0010] In one embodiment of the present invention, the drive motor of the electric telescopic link is fixedly connected to the lower end of the rod cylinder of the electric telescopic link through a motor mount. The drive motor independently controls the telescopic movement of the electric telescopic link to realize the six-degree-of-freedom pose adjustment of the moving platform assembly.

[0011] In one embodiment of the present invention, the moving platform body is a hexagonal plate structure, with six connecting seats matching the upper Hooke hinge on the lower end edge, and a slide rail mounting seat and an annular slide rail at the center of the upper end. The annular slide rail is provided with a toothed ring for sliding engagement with the circular boss of the moving side docking component, so that the moving side docking component can rotate relative to the moving platform body.

[0012] In one embodiment of the present invention, the moving side docking assembly includes a triangular docking head, a circular boss, and a magnetic docking protrusion. The circular boss is fixed at the center of the end face of the triangular docking head and slides in cooperation with the annular slide rail of the moving platform assembly. There are three magnetic docking protrusions, which are evenly distributed at one end of the circular boss of the triangular docking head and are used to adsorb and fit with the magnetic docking concave end of the stationary side docking seat.

[0013] In one embodiment of the present invention, the stationary docking seat includes an annular base, a triangular channel, a limiting protrusion, and a magnetic docking recess. The triangular channel is located at the center of the stationary docking seat and matches the triangular mating head of the moving side docking assembly. There are three limiting protrusions, which are evenly distributed on the annular base and are used to cooperate with the side of the moving side docking assembly to achieve mechanical limiting. The limiting protrusions are also provided with mounting holes for fixing to the robot to be docked by bolts.

[0014] In one embodiment of the present invention, a locking protection unit is further included. The magnetic attraction component of the locking protection unit includes a magnetic attraction docking protrusion disposed on the moving side docking component and a magnetic attraction docking concave end disposed on the stationary side docking seat. The mechanical limiting component of the locking protection unit includes a triangular mating joint of the moving side docking component and a limiting protrusion of the stationary side docking seat.

[0015] In one embodiment of the present invention, the materials of the static platform base, the moving platform body, the triangular joint of the moving side docking assembly, and the static side docking seat are aluminum alloy with an anodized surface.

[0016] In one embodiment of the present invention, six electrically operated telescopic links are evenly distributed along the circumference of the static platform base to form a triangular support structure. By coordinating and controlling the extension and retraction of each electrically operated telescopic link, the dynamic platform component can achieve six degrees of freedom motion in three-dimensional space.

[0017] The present invention also provides a method for docking modular snake robots using the above-mentioned docking mechanism, comprising the following steps: S1: Adjust the position and orientation of the moving side docking assembly by using the Stewart parallel drive unit to align the triangular joint of the moving side docking assembly with the triangular channel of the stationary side docking seat. S2: Control the electric telescopic linkage to extend synchronously, driving the moving platform assembly and the moving side docking assembly to move towards the stationary side docking seat, so that the triangular joint can pass into the triangular channel; S3: Drive the moving side docking assembly to rotate relative to the moving platform body, so that the magnetic docking protrusion of the moving side docking assembly is aligned with the magnetic docking concave end of the stationary side docking seat. S4: The magnetic surface adheres to the surface, and the limiting protrusion engages with the mechanical limiting position to complete the locking. After docking, the overall position is adjusted by the Stewart parallel drive unit to adapt to environmental requirements.

[0018] The beneficial effects of this invention are as follows: This invention proposes a docking mechanism and method for a Stewart parallel platform-driven modular snake robot. The system utilizes a static platform component fixed to the robot's end effector, a Stewart parallel drive unit to achieve six degrees of freedom motion, and a docking execution unit to complete the docking between the moving and static sides. This solution uses a six-degree-of-freedom mechanism to precisely adjust the posture, ensuring high-precision alignment and stable connection during docking. It solves the problems of low alignment accuracy, insufficient connection stiffness, and weak posture adjustment capability in existing technologies, achieving high-precision docking alignment, enhancing connection stiffness, providing flexible posture adjustment capability, and improving docking reliability. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the docking mechanism in this invention; Figure 2 This is a schematic diagram of the static platform of the docking mechanism in this invention; Figure 3 This is a schematic diagram of the Hooke's hinge structure of the docking mechanism in this invention; Figure 4 This is a schematic diagram of the structure of the docking mechanism after the telescopic connecting rod is connected to the Hooke's hinge in this invention; Figure 5 This is a schematic diagram of the structure outside the moving platform of the docking mechanism in this invention; Figure 6 This is a schematic diagram of the structure inside the moving platform of the docking mechanism in this invention; Figure 7 This is a schematic diagram of the moving side docking assembly of the docking mechanism in this invention; Figure 8 This is a schematic diagram of the static side docking seat of the docking mechanism in this invention; Figure 9 This is a schematic diagram of the docking execution unit of the docking mechanism in this invention during docking.

[0021] The attached figures are labeled as follows: 1. Static platform base; 101. Hooke hinge mounting base; 2. Lower Hooke hinge; 201. Rotating pair; 202. Hinge seat; 3. Electric telescopic linkage; 4. Drive motor; 401. Motor seat; 5. Moving platform body; 501. Slide rail mounting base; 502. Circular slide rail; 503. Connecting seat; 6. Moving side docking assembly; 601. Circular boss; 602. Magnetic docking protrusion; 7. Static side docking seat; 701. Limiting protrusion; 7011. Mounting hole; 702. Magnetic docking concave end; 8. Upper Hooke hinge. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. 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. 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. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. 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 the actual implementation. In the 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.

[0024] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0025] Traditional snake robots often suffer from limited adaptability, maintenance difficulties, and poor functional expandability when faced with complex tasks due to their fixed structure and inability to be reconfigured. The docking mechanisms of existing modular snake robots mostly adopt simple mechanical pins, electromagnetic adsorption, or snap-fit ​​connections, which have problems such as low docking accuracy, insufficient connection rigidity, weak posture adjustment capability, and inability to coordinate the overall posture after docking, thus limiting their ability to work collaboratively in dynamic environments.

[0026] For this, please see Figures 1 to 9 , Figure 1 This application proposes a docking mechanism for a Stewart parallel platform-driven modular snake robot, comprising: A static platform component for attaching to the end effector of a modular snake robot; The Stewart parallel drive unit includes six electric telescopic links 3 and corresponding lower Hooke hinges 2 and upper Hooke hinges 8. The two ends of each electric telescopic link 3 are connected to the static platform assembly through the lower Hooke hinge 2 and to the dynamic platform assembly through the upper Hooke hinge 8, forming a six-degree-of-freedom motion mechanism. The docking execution unit includes a moving-side docking component 6 and a stationary-side docking seat 7. The moving-side docking component 6 is rotatably mounted on the moving platform component, and the stationary-side docking seat 7 is used to fix the front end of the modular snake robot to be docked.

[0027] For ease of understanding, the following explains some key terms in this embodiment: The static platform component serves as the base for the entire docking mechanism. It is fixed to the end of the modular snake robot and provides support for the Stewart parallel drive unit.

[0028] The Stewart parallel drive unit is a six-degree-of-freedom parallel mechanism that connects the static platform assembly and the moving platform assembly through six retractable links, enabling the moving platform assembly to perform translational and rotational movements in three-dimensional space.

[0029] The electric telescopic link 3 is the actuator in the Stewart parallel drive unit. It achieves length adjustment through an internal drive mechanism, thereby changing the position of the moving platform assembly.

[0030] The lower Hooke hinge 2 and the upper Hooke hinge 8 are joints that connect the electric telescopic link 3 to the static platform assembly or the moving platform assembly, allowing the link to deflect within a certain range, thereby ensuring the motion freedom of the Stewart parallel drive unit.

[0031] The moving platform component is the output platform of the Stewart parallel drive unit. Through the coordinated movement of the electric telescopic link 3, it realizes the six-degree-of-freedom pose adjustment in space and carries the docking execution unit.

[0032] A six-degree-of-freedom motion mechanism means that the mechanism can achieve three translational degrees of freedom (movement along the X, Y, and Z axes) and three rotational degrees of freedom (rotation around the X, Y, and Z axes) in three-dimensional space, thereby achieving control over the pose of an object.

[0033] The docking execution unit is the mechanism that completes the physical connection between two modular snake robots. It includes the moving side docking component 6 and the stationary side docking seat 7, which work together to achieve the docking process.

[0034] The moving-side docking assembly 6 is the part of the docking execution unit that is installed on the moving platform assembly. It docks with the stationary-side docking seat 7 and can rotate relative to the moving platform assembly.

[0035] The stationary docking seat 7 is the part of the docking execution unit that is fixed to the front end of the modular snake robot to be docked. As the docked party, it cooperates with the moving docking component 6 to complete the docking.

[0036] This embodiment provides a docking mechanism for a Stewart parallel platform-driven modular snake robot. The stationary platform assembly of this mechanism is configured to be fixed to the end effector of the modular snake robot. As one implementation, the stationary platform assembly can be a flat plate structure, connected to the robot end effector by bolts or welding. Alternatively, the stationary platform assembly can be designed as a connecting block with a preset shape, connected to the robot end effector by snap-fits or pins.

[0037] The Stewart parallel drive unit is the main component of this docking mechanism, comprising six electrically operated telescopic links 3 and corresponding lower and upper Hooke hinges 2 and 8. The electrically operated telescopic links 3 can take various forms; for example, they can consist of a lead screw and nut mechanism driven by a stepper motor, where the length of the link is changed by controlling the rotation of the stepper motor. Alternatively, the electrically operated telescopic links 3 can consist of a gear and rack mechanism driven by a DC motor, where the rotation of the gear drives the linear motion of the rack, thereby achieving the extension and retraction of the link. Please refer to [link to relevant documentation]. Figure 1 and Figure 3 The lower Hooke hinge 2 and the upper Hooke hinge 8 can adopt a universal joint or ball joint structure, such as a structure that includes two pairs of revolute joints 201 and hinge seat 202, so as to allow the connecting rod at the end of the hinge seat 202 to rotate in multiple directions at the connection point.

[0038] Both ends of each electrically operated telescopic link 3 are connected to the stationary platform assembly via a lower Hooke's hinge 2. Specifically, the stationary platform assembly can have multiple connection points, each of which is connected to the lower end of an electrically operated telescopic link 3 via a lower Hooke's hinge 2. These connection points can be holes in the stationary platform assembly, connected to the Hooke's hinge via pins.

[0039] The other end of the electrically operated telescopic link 3 is connected to the moving platform assembly via the upper Hooke hinge 8, thus forming a six-degree-of-freedom motion mechanism. The moving platform assembly can be a plate-like structure with connection points that match the upper Hooke hinge 8. These connection points can be similar to those on the stationary platform assembly, connected to the Hooke hinge via pins. Through the coordinated extension and retraction of the six electrically operated telescopic links 3, the moving platform assembly can achieve translation and rotation in three-dimensional space, thereby obtaining six degrees of freedom.

[0040] The docking execution unit is a component used to achieve physical connection between modules, and it includes a moving-side docking assembly 6 and a stationary-side docking seat 7. The moving-side docking assembly 6 can be a connector with a preset geometry, such as a cylindrical or square plug. The stationary-side docking seat 7 can be a slot or groove that matches the shape of the moving-side docking assembly 6.

[0041] The moving-side docking assembly 6 is rotatably mounted on the moving platform assembly. Alternatively, the moving-side docking assembly 6 can be mounted at the center of the moving platform assembly via a bearing structure, allowing it to rotate about an axis perpendicular to the moving platform assembly. Or, the moving-side docking assembly 6 can be mounted on the moving platform assembly via a turntable structure, allowing it to rotate via an external driving force.

[0042] The stationary side docking seat 7 is used to fix the front end of the modular snake robot to be docked. The stationary side docking seat 7 can be a separate structure, installed on the front end of the robot to be docked by bolts, rivets, or welding. Alternatively, the stationary side docking seat 7 can be integrated into the front end module of the robot to be docked, forming a monolithic structure.

[0043] The docking mechanism in this embodiment achieves six-degree-of-freedom pose adjustment of the moving platform components through a Stewart parallel drive unit, overcoming the problems of low precision, insufficient rigidity, and weak posture adjustment capability of existing docking mechanisms. Therefore, this mechanism enables high-precision autonomous docking between modular snake robots and supports coordinated adjustment of the overall pose after docking, thereby improving the task adaptability, motion stability, and functional expandability of modular snake robots in complex environments such as complex terrain and confined spaces.

[0044] In some embodiments described above in this application, a docking mechanism for a Stewart parallel platform-driven modular snake robot is proposed, which includes a static platform assembly for fixing to the end of the modular snake robot. However, if the structural design of the static platform assembly is not targeted, the electric telescopic linkage connection of the Stewart parallel drive unit may be unstable, affecting the structural rigidity and pose adjustment accuracy of the entire docking mechanism.

[0045] For this, please see Figure 1 and Figure 2 This application further proposes that the static platform assembly includes a static platform base 1, which is a hexagonal plate structure, and six Hooke hinge mounting seats 101 are evenly arranged on its edge for connecting to the electric telescopic link 3 through the lower Hooke hinge 2.

[0046] Specifically, the static platform base 1 is the core structure of the static platform assembly, serving as the fixed foundation for the entire Stewart parallel drive unit. It supports and secures the lower Hooke's hinge 2 of the Stewart parallel drive unit, thereby indirectly supporting the electrically telescopic links 3. It is a key structure connecting the docking mechanism to the end effector of the modular snake robot. The static platform base 1 can be manufactured using a one-piece molding or multi-part assembly method to ensure sufficient strength and stability. Its material selection should consider lightweight and high strength, such as aluminum alloys and carbon fiber composites. The hexagonal plate structure design of the static platform base 1 provides uniform and symmetrical mounting points for the six electrically telescopic links 3, which is beneficial for achieving the stability and kinematic performance of the Stewart parallel mechanism. The plate structure provides sufficient mounting surface and structural rigidity. This structure can be precisely formed into a hexagonal plate structure through CNC machining, casting, or 3D printing, ensuring dimensional accuracy and surface flatness for the precise installation of subsequent components. The six Hooke's hinge mounting seats 101 are structures specifically designed for mounting the lower Hooke's hinge 2, evenly distributed along the edges of the static platform base 1. These provide standardized, precise connection points, ensuring the lower Hooke's hinge 2 can be securely mounted and allowing the electrically operated telescopic link 3 to deflect within a certain range to accommodate the motion requirements of the Stewart mechanism. Even distribution helps maintain the symmetry and stability of the mechanism. The Hooke's hinge mount 101 can be designed as a boss, groove, or structure with threaded holes, connected to the lower Hooke's hinge 2 by bolts, pins, or other fasteners. Its position and dimensions must be precisely calculated to meet the kinematic requirements of the Stewart mechanism. The connection between the lower Hooke's hinge 2 and the electrically operated telescopic link 3 clarifies the function of the Hooke's hinge mount 101, namely, as the interface between the lower Hooke's hinge 2 and the stationary platform base 1. The lower Hooke's hinge 2 allows the electrically operated telescopic link 3 to rotate in two orthogonal directions, thus achieving six degrees of freedom motion of the Stewart mechanism. The lower Hooke's hinge 2 typically consists of two mutually perpendicular pivots, connected to the Hooke's hinge mount 101 and the two ends of the electrically operated telescopic link 3 by pins or bolts. The connection should ensure zero or minimal clearance to guarantee motion accuracy.

[0047] By specifically designing the static platform assembly as a hexagonal plate-shaped static platform base 1, and evenly arranging six Hooke hinge mounting seats 101 along its edges, this application provides a structurally stable and precisely connected reference platform for the Stewart parallel drive unit. The hexagonal plate-shaped structure ensures the symmetrical distribution and uniform force distribution of the electric telescopic linkage 3, effectively improving the structural rigidity of the entire docking mechanism. Simultaneously, the dedicated Hooke hinge mounting seats 101 guarantee a stable connection between the lower Hooke hinge 2 and the static platform base 1, thereby improving the motion accuracy and position adjustment stability of the Stewart parallel mechanism and avoiding connection loosening or accuracy reduction problems caused by an unreasonable base structure.

[0048] In some embodiments described above in this application, a Stewart parallel drive unit is proposed, comprising six electrically operated telescopic links 3, which coordinates the telescopic movements of these links to achieve six-degree-of-freedom pose adjustment of the moving platform assembly. However, in achieving high-precision and high-stability pose adjustment, ensuring that each electrically operated telescopic link 3 can be driven precisely and independently to avoid pose deviations caused by uncoordinated driving is a technical problem that needs to be solved.

[0049] For this, please see Figure 1 and Figure 4 This application further proposes that the drive motor 4 of the electric telescopic link 3 is fixedly connected to the lower end of the rod cylinder of the electric telescopic link 3 through the motor base 401, and the drive motor 4 independently controls the telescopic movement of the electric telescopic link 3 to realize the six-degree-of-freedom pose adjustment of the moving platform component.

[0050] Specifically, the drive motor 4 is the core power source for realizing the telescopic movement of the electric telescopic linkage 3. It typically uses a servo motor or stepper motor with high-precision control capabilities, capable of accurately outputting torque and speed according to control commands. Through cooperation with a reduction mechanism (such as a planetary gear reducer) and a lead screw and nut mechanism, the rotational motion of the drive motor 4 is converted into the linear telescopic motion of the electric telescopic linkage 3. The motor mount 401 is a structural component used to securely mount the drive motor 4 onto the electric telescopic linkage 3. It is typically made of high-strength materials and precision-machined to ensure that the drive motor 4 does not experience displacement or vibration during operation, thus guaranteeing transmission accuracy. The design of the motor mount 401 must consider structural matching with the lower end of the telescopic linkage 3's cylinder to achieve a reliable connection. The lower end of the telescopic linkage 3's cylinder is the fixed part of the electric telescopic linkage 3, providing a stable mounting base for the drive motor 4. Fixing the drive motor 4 here integrates the entire drive unit inside or adjacent to the linkage, forming a compact structure, reducing external connecting parts and transmission chains, and improving the overall rigidity and response speed of the system. Independent control of the telescopic movement of the electric telescopic links 3 means that each electric telescopic link 3 is equipped with an independent drive motor 4 and a corresponding control circuit. Each drive motor 4 receives independent commands from the main controller and precisely adjusts the length of its corresponding electric telescopic link 3 according to the commands. This independent control mechanism is key to realizing the six-degree-of-freedom motion of the Stewart parallel mechanism. It allows the system to calculate the precise length of each link based on the target pose and drive them into position respectively, thereby achieving precise pose adjustment of the moving platform assembly. Achieving six-degree-of-freedom pose adjustment of the moving platform assembly means that the moving platform assembly can achieve precise control of three translational degrees of freedom (X, Y, Z directions) and three rotational degrees of freedom (rotation about the X, Y, Z axes) in three-dimensional space. By independently and coordinately controlling the extension and retraction of the six electric telescopic links 3, the Stewart parallel mechanism can precisely position the moving platform assembly to the required spatial position and posture, which is crucial for high-precision docking of modular snake robots.

[0051] Through the above technical solution, the drive motor 4 is directly fixed to the lower end of the electric telescopic link 3 via the motor mount 401, achieving a high degree of integration between the drive motor 4 and the electric telescopic link 3. This integrated design allows each electric telescopic link 3 to have an independent drive source and control capability, thereby avoiding the transmission gap, synchronization error, and structural complexity problems that may arise from traditional centralized drive or external transmission schemes. Since the telescopic movement of each electric telescopic link 3 is independently and precisely controlled by its dedicated drive motor 4, the Stewart parallel drive unit can execute the six-degree-of-freedom pose adjustment commands of the moving platform component more efficiently and accurately. This significantly improves the positioning accuracy and attitude stability of the moving platform component in space, providing a solid technical guarantee for the precise alignment and reliable locking of the moving side docking component 6 and the stationary side docking seat 7 during the modular snake robot docking process, effectively solving the pose deviation problem caused by drive incoordination.

[0052] In some embodiments described above in this application, a Stewart parallel drive unit is proposed to connect a moving platform assembly via six electrically operated telescopic links 3 and corresponding lower and upper Hooke hinges 2 and 8, forming a six-degree-of-freedom motion mechanism. The moving-side docking assembly 6 is rotatably mounted on the moving platform assembly. However, ensuring structural stability, precise transmission, and effective support for the six-degree-of-freedom motion mechanism, while providing a reliable rotating platform for the moving-side docking assembly 6, is a technical problem that needs to be solved when implementing the structural design of the moving platform assembly and its rotational connection with the moving-side docking assembly 6.

[0053] For this, please see Figure 1 , Figure 5 and Figure 6 This application further proposes that the moving platform body 5 is a hexagonal plate structure, with six connecting seats 503 matching the upper Hooke hinge 8 on the lower end edge, and a slide rail mounting seat 501 and an annular slide rail 502 provided at the center of the upper end. The annular slide rail 502 is provided with a toothed ring for slidingly engaging with the circular boss 601 of the moving side docking component 6, so that the moving side docking component 6 can rotate relative to the moving platform body 5.

[0054] Specifically, the moving platform body 5, serving as the moving platform of the Stewart parallel drive unit, is designed as a hexagonal plate structure. This structural design provides excellent structural symmetry and stability, evenly distributing the load from the six electrically operated telescopic links 3, thus providing a robust and stable base for the entire six-degree-of-freedom motion mechanism. The moving platform body 5 is typically made of high-strength, lightweight materials, such as anodized aluminum alloy, to effectively reduce overall weight while ensuring sufficient rigidity. Six connecting seats 503 are evenly distributed along its lower end edge. These connecting seats 503 are specifically designed for precise matching and connection with the upper Hooke hinge 8. They can be lugs, plates, or reinforced areas integrated into the edge of the plate structure, reliably connected to the upper Hooke hinge 8 via bolts or pins, ensuring the stability of the Stewart parallel mechanism's kinematic chain.

[0055] In addition, to enable the rotation function of the moving side docking assembly 6, a slide rail mounting base 501 and an annular slide rail 502 are provided at the center of the upper end face of the moving platform body 5. The slide rail mounting base 501 is the fixed base for the annular slide rail 502, and can be a pre-reserved protrusion or recess on the moving platform body 5 for precise installation of the annular slide rail 502. The annular slide rail 502 is usually made of a highly wear-resistant material, such as stainless steel or engineering plastic, and its cross-sectional shape (such as V-shaped, U-shaped, or rectangular) is optimized to accommodate the sliding fit of the circular boss 601 of the moving side docking assembly 6. The annular slide rail 502 is also provided with a gear ring, which can be integrally formed with the annular slide rail 502, or it can be a separate gear ring fixed to the annular slide rail 502 by bolts, riveting, or interference fit. The setting of the gear ring enables the moving side docking assembly 6 to achieve precise and controllable rotational movement by meshing with the drive gear (usually driven by a small motor). The circular boss 601 of the moving side docking assembly 6 slides with the annular slide rail 502. The circular boss 601 is usually a cylindrical or conical protrusion at the center of the bottom of the moving side docking assembly 6. Its outer diameter is precisely matched with the inner diameter or groove of the annular slide rail 502. Low-friction rotation is achieved through bearings, bushings or direct sliding contact, so that the moving side docking assembly 6 can rotate smoothly and concentrically relative to the moving platform body 5.

[0056] Through the above technical solution, the moving platform body 5 is designed as a hexagonal plate structure, and a connecting seat 503 matching the upper Hooke hinge 8 is provided, which effectively enhances the structural stability of the moving platform component and ensures the accuracy and reliability of the six-degree-of-freedom motion of the Stewart parallel drive unit. Simultaneously, a slide rail mounting seat 501 and an annular slide rail 502 are provided at the center of the upper end face, and a gear ring is integrated on the annular slide rail 502, enabling the circular boss 601 of the moving side docking component 6 to achieve a smooth and precise sliding engagement with the annular slide rail 502. This design not only provides stable rotational support for the moving side docking component 6, but also achieves controllable rotational drive through the gear ring, greatly improving the flexibility and accuracy of the docking mechanism in attitude adjustment and alignment under complex environments. It effectively solves the technical problem of how to provide a stable and precise rotational platform for the moving side docking component 6 while supporting six-degree-of-freedom motion, thereby improving the success rate and efficiency of modular snake robot docking.

[0057] In some embodiments described above in this application, a mechanism for docking modular snake robots is proposed, wherein the docking execution unit includes a rotatably mounted moving-side docking assembly and a stationary-side docking seat. However, in the actual docking process, how to ensure precise mechanical guidance, reliable rotational alignment, and a stable adsorption connection between the moving-side docking assembly and the stationary-side docking seat to cope with minor deviations and external interference that may occur during robot docking is a technical problem that needs further resolution.

[0058] For this, please see Figure 1 and Figure 7 This application further proposes a moving-side docking assembly 6, which includes a triangular docking connector, a circular boss 601, and a magnetic docking protrusion 602. The circular boss 601 is fixed to the center of the end face of the triangular docking connector and slides in cooperation with the annular slide rail 502 of the moving platform assembly. Three magnetic docking protrusions 602 are evenly distributed at one end of the circular boss 601 of the triangular docking connector, for adsorption and contact with the magnetic docking concave end 702 of the stationary-side docking seat 7.

[0059] The triangular butt joint is designed with a specific geometry, its primary function being to provide initial mechanical guidance and coarse positioning during the docking process. Through its non-circular profile, the butt joint can mate with a corresponding complementary shape (e.g., a triangular channel) on the stationary side docking seat 7, thereby restricting the rotational freedom of the moving side docking assembly 6 in the initial stages of docking and guiding it to a roughly correct angular position. This design helps reduce the search range for subsequent fine alignment, improving docking efficiency.

[0060] The circular boss 601 is a cylindrical or frustum-shaped protruding structure whose core function is to serve as a mechanical interface for relative rotation between the moving-side docking assembly 6 and the moving platform assembly. The circular boss 601 is fixed to the center of the end face of the triangular docking joint, ensuring the accuracy of the rotation axis. It slides in engagement with the annular slide rail 502 on the moving platform assembly, allowing the moving-side docking assembly 6 to rotate smoothly and precisely around its central axis after initial mechanical positioning. This sliding engagement mechanism is crucial for achieving precise alignment between the subsequent magnetic docking protrusion 602 and the magnetic docking concave end 702.

[0061] The magnetic docking protrusion 602 is a magnetic element used to achieve the final adsorption connection. It is designed to be protruding, allowing for better contact and self-alignment with the magnetic docking recess 702 on the stationary docking seat 7. In this embodiment, there are three magnetic docking protrusions 602, evenly distributed at one end of the circular protrusion 601 of the triangular docking joint. This three-point even distribution not only provides balanced magnetic force, ensuring a stable and secure connection after docking, but also assists in achieving minute self-alignment during the docking process, further improving the success rate and stability of the docking. The magnetic docking protrusion 602 achieves rapid and reliable adsorption and bonding with the magnetic docking recess 702 of the stationary docking seat 7 through magnetic force, thereby completing the final locking during the docking process.

[0062] Through the above technical solution, the triangular joint of the moving-side docking assembly 6 can perform preliminary mechanical guidance and coarse positioning with the triangular channel of the stationary-side docking seat 7 (as described in subsequent embodiments), effectively limiting the initial rotational freedom during the docking process. Subsequently, the sliding engagement of the circular boss 601 with the annular slide rail 502 of the moving platform assembly allows the moving-side docking assembly 6 to perform precise rotational adjustments based on the preliminary positioning, thereby achieving precise alignment between the magnetic docking protrusion 602 and the magnetic docking concave end 702 of the stationary-side docking seat 7. The three evenly distributed magnetic docking protrusions 602 not only provide stable three-point contact but also achieve rapid and reliable adsorption and bonding through magnetic force, ensuring the stability and anti-interference capability of the docking. This design effectively solves the problems of pose deviation and alignment difficulties that may occur during the docking process, significantly improving the success rate and reliability of modular snake robot docking.

[0063] In some embodiments described above in this application, the position of the moving-side docking assembly 6 is adjusted using a Stewart parallel drive unit to dock with the stationary-side docking seat 7. However, in actual docking, relying solely on the position adjustment of the moving-side docking assembly 6 may not be sufficient to ensure precise alignment, mechanical stability of the connection, and secure fixing of the stationary-side docking seat 7, especially in the presence of external disturbances or under heavy loads. This could lead to unstable docking or connection failure.

[0064] For this, please see Figure 1 , Figure 8 and Figure 9 This application further proposes that the stationary docking seat 7 includes an annular base, a triangular channel, a limiting protrusion 701, and a magnetic docking recess 702. The triangular channel is located at the center of the stationary docking seat 7 and matches the triangular mating joint of the moving side docking assembly 6. There are three limiting protrusions 701, which are evenly distributed on the annular base and are used to cooperate with the side of the moving side docking assembly 6 to achieve mechanical limiting. The limiting protrusions 701 are also provided with mounting holes 7011 for fixing to the robot to be docked by bolts.

[0065] Specifically, the annular base, as the main structure of the stationary docking seat 7, provides a stable installation platform and support for other components. Its annular design facilitates adaptation and connection with the front end structure of the modular snake robot to be docked. A triangular channel is located at the center of the stationary docking seat 7, and its geometry precisely matches the triangular connector of the moving docking assembly 6. During the docking process, when the moving docking assembly 6 approaches the stationary docking seat 7, the triangular connector can smoothly slide into the triangular channel, achieving rapid and accurate radial and angular alignment through shape guidance, effectively correcting initial minor deviations and ensuring precise insertion of the docking components.

[0066] Three limiting protrusions 701 are evenly distributed along the annular base. These protrusions 701 form a tight fit with the side of the moving-side docking assembly 6 after the triangular connector of the moving-side docking assembly 6 is fully engaged in the triangular channel. This fit not only provides additional mechanical support, further restricting relative movement after docking and enhancing connection stability, but also provides reliable mechanical locking and protection in cases of insufficient magnetic docking force or external impact, preventing accidental detachment of the docked parts. Furthermore, mounting holes 7011 are provided on the limiting protrusions 701. These mounting holes 7011 allow the stationary-side docking seat 7 to be securely fixed to the front end of the modular snake robot to be docked using bolts. This bolting method ensures the stability of the stationary-side docking seat 7 during docking operations and subsequent robot movements and work, preventing loosening or detachment, thereby guaranteeing the reliability and safety of the entire docking mechanism. The magnetic docking concave end 702 usually has a permanent magnet or electromagnet embedded in it. Its function is to provide an attraction force in the final stage of docking, so as to achieve a fast and impact-free initial connection and maintain a tight fit between the docking parts.

[0067] Through the above technical solution, the stationary docking seat 7 is designed as a composite structure comprising an annular base, a triangular channel, a limiting protrusion 701, and a magnetic docking recess 702. The triangular channel matches the triangular connector of the moving-side docking assembly 6, providing precise mechanical guidance and alignment during docking, effectively correcting initial deviations and ensuring docking accuracy. The limiting protrusion 701 engages with the side of the moving-side docking assembly 6, providing additional mechanical limiting and support after docking, enhancing connection stability, and offering reliable mechanical protection against accidental detachment under external force or insufficient magnetic attraction. The magnetic docking recess 702 works in conjunction with the magnetic docking protrusion 602 of the moving-side docking assembly 6 to achieve rapid and tight adsorption and bonding. Furthermore, the mounting hole 7011 on the limiting protrusion 701 allows the stationary docking seat 7 to be securely fixed to the robot to be docked using bolts, ensuring the stability of the entire docking mechanism during robot movement and operation. These structures work together to significantly improve the docking accuracy, connection stability, and mechanical reliability of the modular snake robot docking mechanism, solving the problem that it is difficult to achieve accurate, stable, and secure docking by relying solely on posture adjustment.

[0068] In some embodiments described above, this application proposes a technical solution that uses a Stewart parallel drive unit to adjust the pose of the moving-side docking assembly and enable it to dock with the stationary-side docking seat. However, in practical applications, especially when modular snake robots require frequent docking or operate in complex environments, relying solely on initial pose adjustment and contact may not guarantee the stability, reliability, and accuracy of the connection after docking. During or after docking, external disturbances may cause the connection to loosen, misalign, or even detach, thereby affecting the overall function and operational efficiency of the robot system.

[0069] For this, please see Figure 1 , Figures 7 to 9 This application further proposes a docking mechanism, which includes a locking protection unit. The magnetic attraction component of the locking protection unit includes a magnetic attraction docking protrusion 602 disposed on the moving side docking component 6 and a magnetic attraction docking concave end 702 disposed on the stationary side docking seat 7. The mechanical limiting component of the locking protection unit includes a triangular butt joint of the moving side docking component 6 and a limiting protrusion 701 of the stationary side docking seat 7.

[0070] The locking protection unit is designed to ensure a stable and reliable mechanical connection and positioning of the modular snake robot docking mechanism after initial docking, preventing accidental separation or misalignment due to external vibration, impact, or operational errors. It typically consists of cooperating magnetic and mechanical limiting components that work together to provide dual protection.

[0071] The magnetic attraction assembly is part of the locking and protection unit, primarily using magnetic force to achieve initial attraction and positioning of the docking interface. It includes a magnetic attraction protrusion 602 located on the moving side of the docking assembly 6 and a magnetic attraction concave end 702 located on the stationary side of the docking seat 7. The magnetic attraction protrusion 602 and the magnetic attraction concave end 702 are typically constructed using permanent magnets or electromagnets and their corresponding magnetically conductive materials, or another set of magnets. When the two approach each other, the magnetic force guides them to automatically align and engage, providing a certain pulling force to prevent relative displacement of the docking surfaces before the mechanical restraints are fully engaged. This magnetic attraction helps provide flexible guidance and pre-tightening force during the docking process, simplifying operation and improving docking efficiency.

[0072] The magnetic docking protrusion 602 is a magnetic structure on the moving side docking assembly 6, typically designed as a protrusion to engage with the magnetic docking recess 702 on the stationary side docking seat 7. It can contain a permanent magnet, such as a neodymium iron boron magnet, or be designed as an electromagnet structure, with magnetic force controlled by switching on and off electricity. Its surface can be treated for wear resistance and corrosion resistance to adapt to different working environments.

[0073] The magnetic docking recess 702 is a magnetic structure on the stationary docking seat 7, typically designed as a recess to match the magnetic docking protrusion 602. It can be a groove with an embedded permanent magnet or a groove made of magnetically conductive material, forming a magnetic circuit with the magnet of the magnetic docking protrusion 602 to generate an attractive force. Its geometry and dimensions precisely match the magnetic docking protrusion 602 to ensure accurate alignment and stable attraction during docking.

[0074] The mechanical limiting assembly is another part of the locking protection unit, designed to provide precise positioning and strong mechanical locking force through physical contact and geometric fit. It includes the triangular butt joint of the moving-side docking assembly 6 and the limiting protrusion 701 of the stationary-side docking seat 7. This mechanical structure can withstand large shear and pull-out forces, ensuring that the connection remains stable under external loads after docking, preventing relative movement.

[0075] The triangular mating joint is a key geometric feature on the moving-side mating assembly 6, and its shape is triangular. This design allows for precise engagement with the corresponding triangular channel in the stationary-side mating seat 7, providing directional restraint and radial positioning. The triangular geometry provides excellent guidance during insertion and rotation, and once fully engaged, it effectively prevents relative rotation and radial displacement of the moving-side mating assembly 6 relative to the stationary-side mating seat 7.

[0076] The limiting protrusions 701 are structures on the stationary side mating seat 7, typically evenly distributed, used to mate with the sides of the moving side mating assembly 6 (especially the sides of the triangular mating joint). After mating, these protrusions can engage or abut against specific positions on the moving side mating assembly 6, thereby providing additional mechanical support and limiting function to prevent accidental axial and radial movement of the moving side mating assembly 6. Their shape and position are precisely designed to ensure a tight fit with the triangular mating joint, achieving reliable mechanical locking.

[0077] By introducing a locking protection unit, this application effectively solves the problem of insufficient connection stability during and after the docking process of the modular snake robot. Specifically, the magnetic docking protrusion 602 and magnetic docking concave end 702 in the magnetic attraction assembly provide flexible guidance and adsorption force at the end of the docking process, enabling the moving side docking assembly 6 to automatically and accurately align with the stationary side docking seat 7 and achieve a preliminary stable connection, reducing the difficulty of the docking operation and the stringent requirements for posture control accuracy. Furthermore, the triangular butt joint of the moving side docking assembly 6 in the mechanical limiting assembly forms a tight physical engagement with the limiting protrusion 701 of the stationary side docking seat 7, providing a strong mechanical locking force and effectively preventing relative rotation, radial displacement, and axial separation after docking. This dual protection mechanism combining magnetic attraction and mechanical limiting significantly improves the connection reliability, stability, and resistance to external disturbances of the docking mechanism under complex working conditions, ensuring the overall performance and operational safety of the modular snake robot system after docking.

[0078] In practical applications of modular snake robot docking mechanisms, the main structural components, such as the static platform base, the moving platform body, the triangular joint of the moving side docking assembly, and the static side docking seat, need to possess good structural strength, lightweight characteristics, and excellent corrosion and wear resistance. However, if the materials for these key components are not properly selected or the surface treatment is insufficient, it may lead to excessive overall weight of the mechanism, affecting the robot's movement flexibility and energy consumption. Furthermore, these components are prone to corrosion or wear in complex environments, thereby reducing the reliability and service life of the docking mechanism.

[0079] For this, please see Figure 1 , Figure 2 , Figures 5 to 9 This application further proposes that the triangular butt joints of the static platform base 1, the dynamic platform body 5, the dynamic side docking assembly 6, and the static side docking seat 7 are made of aluminum alloy with an anodized surface.

[0080] The aforementioned static platform base 1, moving platform body 5, the triangular joint of the moving side docking assembly 6, and the static side docking seat 7 are the core structural components of the modular snake robot docking mechanism. They respectively undertake the functions of support, connection, motion transmission, and docking interface. The static platform base 1 serves as the fixed foundation of the entire Stewart parallel drive unit, the moving platform body 5 is the output end of the Stewart parallel mechanism, while the triangular joint of the moving side docking assembly 6 and the static side docking seat 7 directly participate in the physical docking process between robot modules. The structural integrity and surface properties of these components directly affect the overall performance and reliability of the docking mechanism.

[0081] The material used is aluminum alloy, which refers to a lightweight, high-strength material based on aluminum with added alloying elements such as copper, magnesium, manganese, and zinc. A significant characteristic of aluminum alloys is their low density and high specific strength; that is, for the same strength, aluminum alloys weigh far less than steel. Furthermore, aluminum alloys possess good plasticity, are easy to process and form, have excellent electrical and thermal conductivity, and exhibit a certain degree of corrosion resistance in natural environments. In the field of robotics, using aluminum alloys as a structural material can effectively reduce the overall weight of the robot, thereby reducing drive energy consumption and improving the robot's load capacity, motion response speed, and endurance.

[0082] Surface anodizing refers to an electrochemical process in which an anodic current is applied to an aluminum alloy in a specific electrolyte, causing a dense and hard oxide film to form on its surface. The thickness, hardness, and porosity of this oxide film can be precisely controlled through process parameters. After anodizing, the hardness, wear resistance, and corrosion resistance of the aluminum alloy surface are significantly improved. For docking mechanisms, the anodized film effectively resists the erosion of moisture, weak acids, alkalis, and other corrosive media in the external environment, extending the service life of the components. At the same time, its high hardness also enhances the components' ability to resist friction and wear during repeated docking and separation processes, ensuring that the docking mechanism maintains stable performance and precision during long-term use.

[0083] By selecting aluminum alloy as the material for key structural components such as the static platform base 1, the moving platform body 5, the triangular joint of the moving side docking assembly 6, and the static side docking seat 7, and performing anodizing treatment on their surfaces, this application effectively solves the problems of excessive weight, easy corrosion, and easy wear that docking mechanisms may face in practical applications. Specifically, the lightweight characteristics of aluminum alloy significantly reduce the overall mass of the docking mechanism, thereby reducing the load on the modular snake robot and improving its motion flexibility, response speed, and energy efficiency. Simultaneously, after anodizing treatment, a hard, dense, and corrosion-resistant oxide film forms on the surface of these components, greatly enhancing their corrosion resistance in complex or harsh environments, effectively resisting erosion from moisture, chemicals, etc., and extending the service life of the components. Furthermore, the anodized film also endows the components with excellent wear resistance, ensuring that the accuracy and reliability of the docking interface are maintained during frequent docking and separation operations, avoiding performance degradation due to wear. Therefore, this technical solution achieves lightweight, high durability, and long lifespan of the docking mechanism while ensuring structural strength, significantly improving the overall performance and reliability of the modular snake robot.

[0084] In some of the embodiments described above in this application, although a Stewart parallel drive unit is proposed, the layout of its electric telescopic linkage is not clearly defined. This may lead to problems such as insufficient motion stability, complex control algorithms, or difficulty in guaranteeing motion accuracy when the moving platform assembly performs six degrees of freedom motion.

[0085] For this, please see Figure 1 This application further proposes that six electric telescopic links 3 are evenly distributed along the circumference of the static platform base 1 to form a triangular support structure, and the six degrees of freedom of the moving platform component in three-dimensional space can be realized by coordinating and controlling the extension and retraction of each electric telescopic link 3.

[0086] Specifically, the six electrically operated telescopic links 3 are evenly distributed along the circumference of the static platform base 1. This means that the lower Hooke hinges 2 connecting the six electrically operated telescopic links 3 to the static platform base 1 are arranged at equal angular intervals along the edge of the static platform base 1. For example, in the case where the static platform base 1 is a hexagonal plate structure, each lower Hooke hinge 2 can be connected to each vertex of the hexagon or the midpoint of each side, thus forming a symmetrical and uniform distribution in the circumferential direction. This layout ensures the symmetrical transmission of forces and the balance of the structure, providing a basis for the stable movement of the moving platform assembly. Simultaneously, a triangular support structure is formed. In Stewart parallel platforms, this structure typically refers to the connection points of the six electrically operated telescopic links 3 on the static platform base 1 and the moving platform assembly forming a specific geometric configuration. For example, the six lower Hooke hinges 2 on the static platform base 1 can be considered to form two equilateral triangles, or the six upper Hooke hinges 8 on the moving platform assembly can form two equilateral triangles. This structure can effectively resist external loads and ensure the high stiffness and stability of the moving platform assembly during movement. Based on this, the six-degree-of-freedom motion of the moving platform assembly in three-dimensional space is achieved by coordinating and controlling the extension and retraction of each electric telescopic link 3. Coordination control refers to accurately calculating the required extension and retraction of each electric telescopic link 3 using inverse kinematics algorithms based on the target pose (including three-dimensional spatial position and attitude) of the moving platform assembly, and synchronously driving these links to extend and retract. For example, after receiving the pose command from the host computer, the control system uses a preset inverse kinematics model to calculate the length changes of each of the six electric telescopic links 3, and then converts these changes into control signals for the drive motor 4. The drive motor 4 precisely controls the extension and retraction of the electric telescopic links 3. To ensure the synchronization and accuracy of the motion, a closed-loop control method is usually adopted, using sensors to monitor the link length in real time and perform feedback correction, thereby enabling the moving platform assembly to accurately achieve translation along the X, Y, and Z axes and rotation around the X, Y, and Z axes.

[0087] Through the aforementioned technical solution, six electrically operated telescopic links 3 are evenly distributed along the circumference of the static platform base 1, forming a triangular support structure, which greatly optimizes the geometric configuration of the Stewart parallel drive unit. This symmetrical and rigid structural layout enables the moving platform assembly to achieve higher motion stability during six-degree-of-freedom motion, effectively suppressing vibration and swaying. Simultaneously, the optimized geometric configuration simplifies the calculation of the inverse kinematics model, improves the accuracy and response speed of pose control, and ensures that the moving platform assembly can accurately reach the target position and attitude. Furthermore, the uniform force distribution also enhances the overall load-bearing capacity and reliability of the mechanism.

[0088] In some of the embodiments described above in this application, a mechanism for docking modular snake robots is proposed. However, in practical applications, simply having a docking mechanism cannot guarantee that modules can dock efficiently, accurately, and safely. Especially in dynamic or complex environments, ensuring the precise alignment, smooth insertion, and reliable locking of docking components is a key challenge for achieving rapid reconfiguration and stable operation of modular robots.

[0089] In this regard, this application further proposes a method for docking modular snake robots using the aforementioned docking mechanism, the method comprising the following steps: First, the pose of the moving-side docking assembly 6 is adjusted using the Stewart parallel drive unit, aligning the triangular joint of the moving-side docking assembly 6 with the triangular channel of the stationary-side docking seat 7. Specifically, the Stewart parallel drive unit, as a six-degree-of-freedom motion mechanism, can precisely control the pose of the moving platform assembly. In the initial docking phase, the precise control capability of this unit, combined with external sensing devices such as vision sensors, distance sensors, or force sensors, is used to acquire the relative position and attitude information between the moving-side docking assembly 6 and the stationary-side docking seat 7. Based on this information, the control system calculates the required extension and retraction of the six electric telescopic links 3 using an inverse kinematics algorithm, thereby driving the moving platform assembly and its moving-side docking assembly 6 to perform spatial displacement and attitude adjustments until the triangular joint of the moving-side docking assembly 6 and the triangular channel of the stationary-side docking seat 7 are precisely aligned in space, laying the foundation for subsequent insertion operations.

[0090] Secondly, the electric telescopic linkages 3 extend synchronously, driving the moving platform assembly and the moving-side docking assembly 6 to translate towards the stationary-side docking seat 7, allowing the triangular connector to enter the triangular channel. After initial alignment, the control system instructs all six electric telescopic linkages 3 to extend at a preset speed and synchronicity. This synchronous extension ensures that the moving platform assembly and its supported moving-side docking assembly 6 can smoothly translate along a predetermined axis towards the stationary-side docking seat 7, avoiding unnecessary tilting or deflection during insertion. During translation, the triangular connector is guided into the triangular channel of the stationary-side docking seat 7, which provides mechanical guidance, further ensuring the smoothness and accuracy of the insertion process and preventing possible jamming or damage in the initial stages of insertion.

[0091] Next, the moving-side docking assembly 6 is rotated relative to the moving platform body 5, aligning the magnetic docking protrusion 602 of the moving-side docking assembly 6 with the magnetic docking concave end 702 of the stationary-side docking seat 7. After the triangular docking connector is initially inserted into the triangular channel, a precise rotational alignment of the moving-side docking assembly 6 is required to achieve final magnetic attraction and mechanical locking. The moving-side docking assembly 6 is rotatably mounted on the moving platform assembly, with its circular protrusion 601 slidingly engaged with the annular slide rail 502 of the moving platform body 5. At this time, the moving-side docking assembly 6 is rotated about its central axis by a drive mechanism (e.g., a motor mounted on the moving platform body 5 and meshing with the gear ring of the moving-side docking assembly 6). During the rotation, the control system can monitor the rotation angle using an internal encoder or external sensor until the three magnetic docking protrusions 602 on the moving-side docking assembly 6 are precisely aligned circumferentially with the three magnetic docking concave ends 702 on the stationary-side docking seat 7, preparing for final attraction and locking.

[0092] Finally, the magnetic surfaces adhere to each other, and the limiting protrusion 701 engages with the mechanical limiting position, completing the locking. After docking, the Stewart parallel drive unit adjusts the overall posture to adapt to environmental requirements. Once the magnetic docking protrusion 602 and the magnetic docking concave end 702 are aligned, the magnetic force between them will cause them to quickly adhere and form a preliminary connection. At the same time, the limiting protrusion 701 on the stationary docking seat 7 will cooperate with the side of the moving docking assembly 6 (e.g., the side of the triangular docking joint) and engage with the preset mechanical limiting position, providing additional mechanical locking and support, thus forming a stable lock with both magnetic and mechanical protection. After docking, the overall posture of the entire modular snake robot (including the newly connected modules) may need to be adjusted according to the task or environment. At this time, the Stewart parallel drive unit can once again utilize its six-degree-of-freedom posture adjustment capability to adjust the overall posture of the connected modules, such as changing the robot's bending angle, height, or direction, to adapt to new motion trajectories, obstacle avoidance requirements, or operational tasks, ensuring that the robot can perform subsequent work flexibly and efficiently.

[0093] Through the above technical solution, this application provides a systematic and phased modular snake robot docking method, effectively solving problems such as alignment difficulties, unstable insertion, and weak locking that may occur during the docking process between modules. First, by utilizing the six-degree-of-freedom precise pose adjustment capability of the Stewart parallel drive unit, high-precision spatial alignment of the triangular connector of the moving-side docking assembly 6 and the triangular channel of the stationary-side docking seat 7 is ensured, thus avoiding docking failure or mechanical damage due to initial deviation. Second, by controlling the synchronous extension of the electric telescopic linkage 3, a smooth and impact-free translational insertion of the moving-side docking assembly 6 into the stationary-side docking seat 7 is achieved, ensuring the smooth insertion of the triangular connector into the triangular channel and providing initial mechanical guidance. Furthermore, driving the moving-side docking assembly 6 to rotate relative to the moving platform body 5 precisely aligns the magnetic docking protrusion 602 with the magnetic docking concave end 702, creating conditions for subsequent magnetic attraction and mechanical locking. Finally, the magnetic adsorption and adhesion of the magnetic surface and the mechanical limiting of the limiting protrusion 701 are completed synchronously, forming a double-protected and stable locking, greatly improving the reliability and safety of the docking. After docking, the Stewart parallel drive unit can also adjust the overall pose, enabling the robot to quickly adapt to new task or environmental requirements, significantly improving the reconfiguration efficiency and task adaptability of the modular snake robot.

[0094] The following example will provide a more detailed explanation of the above technical solution: Imagine a scenario where a modular snake-like robot (let's call it Robot A) is performing a disaster relief search and rescue mission and needs to cross an obstacle that is wider than its current length. At this moment, another modular snake-like robot (let's call it Robot B) is deployed nearby, ready to dock with Robot A to extend Robot A's overall length, enabling it to cross the obstacle.

[0095] First, the static platform assembly of the docking mechanism is securely fixed to the end of robot A. This static platform assembly includes a hexagonal plate-shaped static platform base 1, with six Hooke hinge mounting seats 101 evenly distributed along its edges, providing a stable connection base for the Stewart parallel drive unit. Simultaneously, the static docking seat 7 of the docking execution unit is fixed to the front end of robot B via mounting holes 7011 on its limiting protrusions 701 using bolts. The static docking seat 7 includes an annular base with a triangular channel at its center and three evenly distributed limiting protrusions 701.

[0096] Next, the first stage of the docking process begins: pose alignment. The Stewart parallel drive unit, consisting of six electrically operated telescopic links 3, starts operating. Each link 3 is connected at both ends to a Hooke hinge mounting base 101 on the stationary platform base 1 via a lower Hooke hinge 2, and to a moving platform assembly via an upper Hooke hinge 8. The moving platform assembly includes a hexagonal plate-shaped moving platform body 5, with six connecting seats 503 on its lower edge that match the upper Hooke hinge 8. The drive motor 4 of each link 3 is fixed to the lower end of the link's cylinder via a motor mount 401, independently controlling the extension and retraction of the link 3. By precisely coordinating and controlling the extension and retraction of these six electrically operated telescopic links 3, the Stewart parallel drive unit can achieve six-degree-of-freedom pose adjustment of the moving platform assembly in three-dimensional space. At this time, the control system drives the moving platform assembly, precisely aligning the triangular connector of the moving-side docking assembly 6 mounted on it with the triangular channel of the stationary-side docking seat 7 at the front end of robot B. Compared to traditional docking mechanisms that rely solely on simple mechanical guidance, Stewart's parallel platform's high-precision drive capability ensures accurate initial alignment and significantly reduces the risk of docking failure.

[0097] After completing the orientation alignment, the second stage begins: insertion into the channel. While maintaining the orientation of the moving-side docking assembly 6, the control system commands the six electrically operated telescopic links 3 to extend synchronously. This synchronous extension drives the moving platform assembly and the moving-side docking assembly 6 as a whole to translate axially towards the stationary-side docking seat 7. The triangular joint of the moving-side docking assembly 6 smoothly inserts into the triangular channel at the center of the stationary-side docking seat 7 until the circular boss 601 of the moving-side docking assembly 6 enters the interior of the stationary-side docking seat 7. The triangular channel of the stationary-side docking seat 7 matches the shape of the triangular joint of the moving-side docking assembly 6, providing effective guidance and ensuring a smooth insertion process.

[0098] The third stage is rotational alignment. A slide rail mounting base 501 and an annular slide rail 502 are located at the center of the upper end face of the moving platform body 5. The annular slide rail 502 has a toothed ring. The moving side docking assembly 6 includes a triangular docking joint, a circular boss 601, and magnetic docking protrusions 602. The circular boss 601 is fixed to the center of the end face of the triangular docking joint and slides in cooperation with the annular slide rail 502 of the moving platform assembly. At this time, the drive mechanism drives the circular boss 601 of the moving side docking assembly 6 to rotate on the annular slide rail 502, causing the moving side docking assembly 6 to rotate relative to the moving platform body 5. The purpose of the rotation is to make the three magnetic docking protrusions 602 on the moving side docking assembly 6 completely aligned with the three corresponding magnetic docking concave ends 702 on the inner wall of the stationary side docking seat 7. This rotatable design solves the problem of difficulty in achieving precise circumferential alignment during the docking process in traditional docking mechanisms, especially when magnetic or mechanical limiting requires a specific angle for engagement.

[0099] Finally, the fourth stage begins: locking and securing. Once the magnetic docking protrusion 602 of the moving-side docking assembly 6 aligns with the magnetic docking concave end 702 of the stationary-side docking seat 7, the two adhere to each other magnetically, generating an initial connection force and completing circumferential locking. Simultaneously, the three evenly spaced limiting protrusions 701 on the stationary-side docking seat 7 engage with the side of the triangular connector of the moving-side docking assembly 6, locking into the mechanical limiting position. This design of a dual locking protection unit combining magnetic attraction and mechanical limiting significantly enhances the connection rigidity and anti-detachment capability after docking. Compared to traditional methods relying solely on a single mechanical pin or electromagnetic attraction, this mechanism provides stronger connection stability and robustness, effectively preventing accidental separation of the module under complex movements or impacts. The stationary platform base 1, the moving platform body 5, the triangular connector of the moving-side docking assembly 6, and the stationary-side docking seat 7 are all made of anodized aluminum alloy, ensuring structural strength and rigidity while reducing overall weight.

[0100] After docking, robots A and B form a longer, integrated unit. The Stewart parallel drive unit continues to operate, coordinating the extension and retraction of the six electrically operated telescopic links 3 to adjust the local or overall pose of the entire assembly. For example, when crossing obstacles, the Stewart platform can adjust the angle at the docking point, enabling the snake robot to better adapt to terrain changes and achieve more flexible movement. This ability to adjust pose even after docking is not found in traditional docking mechanisms, significantly enhancing the modular snake robot's adaptability and execution capabilities in complex environments.

[0101] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A docking mechanism for a Stewart parallel platform-driven modular snake robot, characterized in that, include: A static platform component for attaching to the end effector of a modular snake robot; The Stewart parallel drive unit includes six electric telescopic links (3) and corresponding lower Hooke hinges (2) and upper Hooke hinges (8). One end of each electric telescopic link (3) is connected to the static platform assembly through the lower Hooke hinge (2), and the other end is connected to the dynamic platform assembly through the upper Hooke hinge (8), forming a six-degree-of-freedom motion mechanism. The docking execution unit includes a moving-side docking component (6) and a stationary-side docking seat (7). The moving-side docking component (6) is rotatably mounted on the moving platform component, and the stationary-side docking seat (7) is used to fix the front end of the modular snake robot to be docked.

2. The docking mechanism according to claim 1, characterized in that: The static platform assembly includes a static platform base (1), which is a hexagonal plate structure and has six Hooke hinge mounting seats (101) evenly arranged on its edge for connecting to the electric telescopic link (3) through the lower Hooke hinge (2).

3. The docking mechanism according to claim 1, characterized in that: The drive motor (4) of the electric telescopic link (3) is fixedly connected to the lower end of the rod tube of the electric telescopic link (3) through the motor seat (401). The drive motor (4) independently controls the telescopic movement of the electric telescopic link (3) to realize the six-degree-of-freedom pose adjustment of the moving platform assembly.

4. The docking mechanism according to claim 1, characterized in that: The moving platform assembly includes a moving platform body (5), a slide rail mounting base (501), and an annular slide rail (502). The moving platform body (5) is a hexagonal plate structure. Six connecting seats (503) matching the upper Hooke hinge (8) are provided on the lower end edge. The slide rail mounting base (501) and the annular slide rail (502) are provided at the center of the upper end. The annular slide rail (502) is provided with a toothed ring for slidingly engaging with the circular boss (601) of the moving side docking assembly (6), so that the moving side docking assembly (6) can rotate relative to the moving platform body (5).

5. The docking mechanism according to claim 1, characterized in that: The moving side docking assembly (6) includes a triangular docking head, a circular boss (601) and a magnetic docking protrusion (602). The circular boss (601) is fixed at the center of the end face of the triangular docking head and slides in cooperation with the annular slide rail (502) of the moving platform assembly. There are three magnetic docking protrusions (602), which are evenly distributed at one end of the circular boss (601) of the triangular docking head and are used to adhere to the magnetic docking concave end (702) of the stationary side docking seat (7).

6. The docking mechanism according to claim 1, characterized in that: The stationary docking seat (7) includes an annular base, a triangular channel, a limiting protrusion (701), and a magnetic docking concave end (702). The triangular channel is located at the center of the stationary docking seat (7) and matches the triangular joint of the moving docking assembly (6). There are three limiting protrusions (701) evenly distributed on the annular base, which are used to cooperate with the side of the moving docking assembly (6) to achieve mechanical limiting. The limiting protrusions (701) are also provided with mounting holes (7011) for fixing to the robot to be docked by bolts.

7. The docking mechanism according to claim 1, characterized in that: It also includes a locking protection unit, the magnetic attraction component of which includes a magnetic attraction docking protrusion (602) disposed on the moving side docking component (6) and a magnetic attraction docking concave end (702) disposed on the stationary side docking seat (7); the mechanical limiting component of the locking protection unit includes a triangular butt joint of the moving side docking component (6) and a limiting protrusion (701) of the stationary side docking seat (7).

8. The docking mechanism according to claim 2, characterized in that: The materials of the static platform base (1), the dynamic platform body (5), the triangular joint of the dynamic side docking assembly (6), and the static side docking seat (7) are aluminum alloy with anodized surface.

9. The docking mechanism according to claim 2, characterized in that: The six electric telescopic links (3) are evenly distributed along the circumference of the static platform base (1) to form a triangular support structure. By coordinating and controlling the extension and retraction of each electric telescopic link (3), the dynamic platform component can achieve six degrees of freedom of motion in three-dimensional space.

10. A method for docking a modular snake robot using the docking mechanism according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Adjust the position of the moving side docking assembly (6) by using the Stewart parallel drive unit so that the triangular joint of the moving side docking assembly (6) is aligned with the triangular channel of the stationary side docking seat (7); S2: Control the electric telescopic linkage (3) to extend synchronously, drive the moving platform assembly and the moving side docking assembly (6) to move towards the stationary side docking seat (7), so that the triangular joint can pass into the triangular channel; S3: Drive the moving side docking assembly (6) to rotate relative to the moving platform body (5) so that the magnetic docking protrusion (602) of the moving side docking assembly (6) is aligned with the magnetic docking concave end (702) of the stationary side docking seat (7); S4: The magnetic surface adheres to the surface and the limiting protrusion (701) engages with the mechanical limiting position to complete the locking. After docking, the overall posture is adjusted by the Stewart parallel drive unit to adapt to environmental requirements.

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