Modular snake robot suitable for complex terrain and control system thereof

Abstract

This invention discloses a modular snake-like robot suitable for complex terrain, comprising a snake head module, a snake tail module, and multiple snake body modules and their control system. The snake body module consists of a torso unit and joint units. The joint units employ two dual-axis servos and a cross-shaped orthogonal support structure, enabling movement in both left-right and up-down directions. The torso unit drives rollers via dual-axis motors to propel the robot forward. An auxiliary mechanism is located below the torso unit to distribute the robot's weight and generate a reverse torque to counteract the lateral rolling torque caused by gravity, maintaining stability in complex environments. The snake head module integrates a lidar, depth camera, and onboard computer, using sensors to perceive the environment and process data to control the robot's movement. The snake tail module adopts a tracked structure. This invention allows for the modification of the number of snake body modules according to specific work requirements, combining the terrain adaptability of tracks with the high-speed characteristics of wheels to improve movement stability and adaptability.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic robot technology, specifically relating to a modular snake robot suitable for complex terrain and its control system. Background Technology

[0002] Modular snake-like robots are a typical application of biomimetic principles in robotics. Snakes, with their unique limbless locomotion and highly flexible body structure, demonstrate remarkable adaptability in complex environments. By mimicking the movement patterns and body structure of snakes, snake-like robots have been designed with advantages such as rational structure, flexible control, reliable performance, and strong scalability. They have broad application prospects in many fields, such as searching for the injured in the ruins after earthquakes, landslides, and fires, and surveying and clearing pipelines in confined and dangerous environments.

[0003] Currently, most snake-like robots employ fixed modular designs or single motion modes (such as purely wheeled or purely tracked), making it difficult to simultaneously handle complex terrain and meet the demands of high-speed movement. Furthermore, traditional cylindrical or rectangular body designs lack stability when moving on slopes, and are prone to rolling due to gravity and torque on steep inclines, requiring sensors and complex algorithms to adjust gait, significantly increasing control complexity. Existing snake-like robots have limited flexibility and operating range, with their motion capabilities restricted by the number of joints and robot length, necessitating improvements. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a modular snake robot and its control system suitable for complex terrain. The number of snake body modules can be changed according to specific work needs. An auxiliary mechanism is applied to improve the stability and movement efficiency of the snake robot on slopes and complex terrain. It combines the terrain adaptability of tracks with the high-speed characteristics of wheels to improve the stability and adaptability of movement.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A modular snake-like robot suitable for complex terrain includes a snake head module, a snake tail module, and multiple snake body modules, as well as its control system;

[0007] The snake body module consists of a torso unit and a joint unit. The joint unit uses two dual-axis servos and a cross-shaped orthogonal support structure to achieve two degrees of freedom of movement: left and right, and up and down. The torso unit drives rollers through dual-axis motors to propel the robot forward, and an auxiliary mechanism is located below the torso unit. The snake head module further integrates a lidar, depth camera, and onboard computer based on the snake body module. It uses sensors to perceive the environment and process data to control the robot's movement. The snake tail module adopts a tracked structure, suitable for traversing complex terrain. The snake head module, snake tail module, and snake body module are all connected to the control system.

[0008] Furthermore, the torso unit includes an upper torso shell, a lower torso shell, a dual-axis DC motor, rollers, shaft end fixing sleeves, and auxiliary mechanisms. The upper and lower torso shells are semi-circular structures. The lower edge of the upper torso shell has a partition, the front end of the upper torso shell has a mounting block, the rear end of the upper torso shell has a connecting plate one, and the rear end of the lower torso shell has a connecting plate two. The lower sides of the upper torso shell have retaining rings that insert into grooves on the upper edge of the lower torso shell. The two are connected by screws. Two rollers are located at both ends of the dual-axis DC motor, and the outer sides of the rollers are secured by shaft end fixing sleeves. The lower part of the torso has a motor limiting structure in the middle. The front and rear ends of the motor limiting structure have screw mounting blocks, and the left and right sides of the motor limiting structure have windows. The dual-axis DC motor is fixed inside the motor limiting structure. The auxiliary mechanism includes an arc-shaped connector and an extension plate. The arc-shaped connector is located below the lower part of the torso and is connected to the screw mounting blocks by bolts. The arc-shaped connector has a wheel seam, and the rollers on both sides extend out of the windows and wheel seams. The extension plate is connected to the arc-shaped connector and extends outward. The lowest point of the roller is lower than the lowest point of the auxiliary mechanism.

[0009] Furthermore, the motor limiting structure includes a motor plane, two limiting plates, and four elastic limiting posts. The motor plane is located in the middle of the lower outer shell of the torso, with two limiting plates at the front and rear and four elastic limiting posts on the left and right. The dual-axis DC motor is placed flat on the motor plane, clamped by the two limiting plates at the front and rear and by the four elastic limiting posts on the left and right, thus fixing the dual-axis DC motor.

[0010] Furthermore, the joint unit includes a dual-axis servo motor one, a dual-axis servo motor two, a main servo disk, a secondary servo disk, a snake-body connector, and a cross-shaped orthogonal bracket. The front end of the cross-shaped orthogonal bracket is connected to the output shaft of the dual-axis servo motor one, the rear end of the cross-shaped orthogonal bracket is connected to the dual-axis servo motor two, the snake-body connector is connected to the output shaft of the dual-axis servo motor two, and a mounting groove is provided on the top of the snake-body connector.

[0011] Furthermore, adjacent torso units are connected by mounting blocks at the front end of the upper shell of the torso and mounting slots on the snake-body connectors. Connecting plate one and connecting plate two are connected to dual-axis servo motor one. The torso units and joint units are connected by self-tapping screws.

[0012] Furthermore, the snake head module includes a snake body module, a lidar, an onboard computer, a depth camera, and a camera mounting bracket. The lidar is located above the torso unit, the onboard computer is located above the partition, and a bracket fixing end is provided at the front end of the torso unit. The camera mounting bracket is connected to the bracket fixing end by two hand-tightening screws, and the depth camera is connected to the camera mounting bracket.

[0013] Furthermore, the snake-tail module is a tracked structure, including a snake-tail connector, a track bracket, a fixed shaft one, a track, a shaft end retaining ring, a single-axis DC motor, a fixed shaft two, a gear, a sprocket one, a sprocket two, and a baffle. The snake-tail connector is connected to the track bracket, and the front end of the snake-tail connector is connected to the dual-axis servo motor of the previous snake-body module. The track bracket is equipped with sprocket one and sprocket two through fixed shaft one and fixed shaft two, respectively. The single-axis DC motor is fixed on the track bracket, and the output shaft of the single-axis DC motor is connected to the gear. The gear meshes with the inner gear of sprocket two. The baffle is set on the outside of the track bracket, and the track meshes with the outer gears of sprocket one and sprocket two.

[0014] The control system includes a perception fusion layer, a navigation planning layer, a communication control layer, a motion execution layer, and a power management layer.

[0015] The perception fusion layer consists of a depth camera, lidar, GNSS module, and IMU module, which acquires environmental information and its own pose information to perform preliminary perception fusion.

[0016] The navigation planning layer consists of a computer and an onboard computer. It receives data from the perception fusion layer, analyzes and makes decisions to achieve path planning.

[0017] The communication control layer consists of a Bluetooth module and a voice recognition module, enabling human-computer interaction control;

[0018] The motion execution layer consists of a servo controller and several dual-axis servos. It receives instructions from the host computer and the main controller, sends command sets through a serial bus to realize the motion execution of the servos, and controls dual-axis DC motors and single-axis DC motors to drive the drive wheel and tracks forward.

[0019] The power management layer consists of power supplies and power management modules, providing stable power to the other four layers.

[0020] The control system uses the Ubuntu 20.04 operating system and implements motion control, environmental perception, mapping, path planning and communication functions through ROS1 noetic.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) This invention provides a modular snake robot suitable for complex terrain. By connecting adjacent snake body modules in series with connecting components, a multi-joint continuous motion chain is constructed. The number of snake body module groups of the snake robot can be increased or decreased according to specific work needs, which enhances the robot's flexibility and operating range, solves the problem that the robot's motion capability is limited by the number of joints and the robot's length, and improves the environmental adaptability of the snake robot.

[0023] (2) This invention employs a drive-assist mechanism that can distribute the robot's weight, generate a reverse torque to counteract the rolling torque caused by gravity, increase the contact area with the ground to keep the robot stable when moving on slopes, and avoid rolling due to gravity torque when facing steep slopes. In environments with small obstacles such as grass, gravel, and rocky slopes, the mechanism can push the obstacles to assist the robot's movement. This mechanism is lightweight and simple, reducing the robot's dependence on complex algorithms and sensors, improving control efficiency, and significantly improving the stability and movement efficiency of the snake robot on slopes and complex terrain.

[0024] (3) This invention combines the advantages of wheeled and tracked snake robots. The snake body adopts a wheeled structure, while the snake tail adopts a tracked structure. The snake robot's movement mode can be switched between wheeled and tracked modes by disassembling modules to adapt to different road environments. The wheeled structure can switch between passive and active wheeled modes according to task requirements. The combined use of wheels and tracks improves the stability and adaptability of the snake robot's movement by combining the terrain adaptability of tracks with the high-speed characteristics of wheels.

[0025] (4) The present invention adopts a single-joint dual-degree-of-freedom design. Two orthogonal dual-axis servos are connected by a cross orthogonal bracket, which enables a single joint unit to achieve compound motion, thereby increasing the mobility and flexibility of the snake robot.

[0026] (5) This invention collects environmental data and posture data of the snake robot from its surroundings using a lidar, depth camera, GNSS module, and IMU module, enabling real-time localization and map building for the snake robot and achieving integrated navigation. Furthermore, it directly issues commands to the robot via a voice module and Bluetooth communication, thus realizing motion control of the snake robot. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 This is a schematic diagram of the snake-body module in an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the joint unit in an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the torso unit in an embodiment of the present invention.

[0031] Figure 5 This is an exploded view of the torso unit in an embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram of the motor limiting structure in an embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram of the snake head module in an embodiment of the present invention.

[0034] Figure 8 This is an exploded view of the snake head module in an embodiment of the present invention.

[0035] Figure 9 This is a schematic diagram of the snake tail module in an embodiment of the present invention.

[0036] Figure 10 This is an exploded view of the snake tail module in an embodiment of the present invention.

[0037] Figure 11 This is a schematic diagram of the control system structure of the present invention.

[0038] List of identifiers in attached diagrams:

[0039] 1. Snake head module, 2. Snake body module, 3. Snake tail module, 4. Torso unit, 5. Joint unit, 6. Dual-axis servo motor one, 7. Main rudder disk, 8. Snake body connector, 9. M3*6 screw, 10. Secondary rudder disk, 11. M2*6 self-tapping screw, 12. Phillips head bracket, 13. Mounting slot, 14. Shaft end fixing sleeve, 15. Roller, 16. Lower torso shell, 17. Auxiliary mechanism, 18. M3 nut, 19. Screw mounting block, 20. M3*10 screw, 21. Dual-axis DC motor, 22. M3*5 screw, 23. Mounting block, 24. Upper torso shell, 25. LiDAR, 26. Dual-axis servo motor two, 27. Bracket fixing end. 28. Onboard computer; 29. ​​M3*4 screw; 30. Hand screw; 31. Camera mounting bracket; 32. Depth camera; 34. Track bracket; 35. Fixed shaft one; 36. Track; 37. Shaft end retaining ring; 38. Single-axis DC motor; 39. Fixed shaft two; 40. Gear; 41. Sprocket two; 42. Sprocket one; 43. Baffle; 44. M4*6 screw; 45. M2*4 self-tapping screw; 46. Partition; 47. Connecting plate one; 48. Connecting plate two; 49. Groove; 50. Motor plane; 51. Window; 52. Arc-shaped connector; 53. Extension plate; 54. Wheel seam; 55. Limiting plate; 56. Elastic limiting post; 57. Snap ring. Detailed Implementation

[0040] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] As shown in the figure, the present invention discloses a modular snake robot and its control system suitable for complex terrain. The structure includes a snake head module 1, a snake tail module 3, and multiple snake body modules 2. The snake body module 2 consists of a torso unit 4 and a joint unit 5. The joint unit 5 adopts a structure of two dual-axis servo motors 6 and 26 and a cross-shaped orthogonal support 12 to realize two degrees of freedom of movement: left and right and up and down. The torso unit 4 drives the rollers 15 to move the robot forward through a dual-axis DC motor 21. The auxiliary mechanism 17 below the torso unit 4 is used to improve the stability of the robot when facing complex environments such as slopes. The snake head module 1 integrates a snake body module 2, a LiDAR 25, a depth camera 32, an onboard computer 28, and other hardware. It uses sensors to perceive the environment and process data to control the robot's movement. The snake tail module 3 adopts a tracked structure, which has good terrain adaptability and is suitable for traversing complex terrains. The overall control system is divided into five levels: perception fusion, navigation planning, communication control, motion execution, and power management. It adopts a modular design, which is easy to expand and upgrade. It runs on the Ubuntu 20.04 system and uses ROS1 noetic to realize various functions such as motion control, environmental perception, mapping, path planning, and communication. This robot combines the characteristics of wheeled and tracked vehicles and uses auxiliary mechanisms to improve its movement efficiency and stability in complex terrains, and has strong adaptability and control precision.

[0042] Figure 1 This is a schematic diagram of the overall structure of the invention. The snake-like robot consists of a snake head module 1, a snake tail module 3, and six snake body modules 2 connected in series, forming a continuous motion chain for the robot. The snake body module 2 consists of a torso unit 4 and a joint unit 5. The snake head module 1 and the torso unit 4, adjacent torso units, and the torso unit 4 and the snake tail module 3 are all connected by the joint unit 5. The joint unit 5 consists of two orthogonal dual-axis servos, with two degrees of freedom. The number of snake body modules is variable, and the wheels are detachable to adapt to different working environments.

[0043] Figure 2 This is a schematic diagram of the snake-body module in an embodiment of the present invention. The snake-body module consists of a torso unit 4 and a joint unit 5. The front ends of adjacent torso units are connected to a dual-axis servo motor 6 via a connecting plate 47 and a connecting plate 48. The rear ends are connected by M3 screws via mounting blocks 23 on the upper torso shell 24 and the lower torso shell 16 and mounting slots 13 on the snake-body connector 8. The torso unit 4 and the joint unit 5 are connected by M2 self-tapping screws.

[0044] Figure 3This is a schematic diagram of the joint unit in this embodiment of the invention. The joint unit 5 consists of a dual-axis servo motor 6, a dual-axis servo motor 26, a main servo disk 7, a secondary servo disk 10, a snake-body connector 8, and a cross-shaped orthogonal bracket 12. The two dual-axis servos 6 and 26 have identical structures and are arranged perpendicularly to each other. The splined shaft of the dual-axis servo motor is connected to the main servo disk 7, and the smooth shaft is connected to the secondary servo disk 10. The two dual-axis servos are connected by the cross-shaped orthogonal bracket 12. One end of the cross-shaped orthogonal bracket 12 is connected to the main and secondary servo disks of dual-axis servo motor 6 using M3*6 screws 9, and the other end is connected to the housing of dual-axis servo motor 26 using M2*6 self-tapping screws 11. The snake-body connector 8 is connected to the main and secondary servo disks of dual-axis servo motor 26 using M3*6 screws 9. This joint module has two degrees of freedom, enabling the snake-body module 2 to swing left and right and up and down.

[0045] Figure 4 This is a schematic diagram of the torso unit in an embodiment of the present invention. The torso unit 4 consists of an upper torso shell 24, a lower torso shell 16, a dual-axis DC motor 21, rollers 15, axle end fixing sleeves 14, and an auxiliary mechanism 17. The auxiliary mechanism 17 generates a reverse torque to counteract the lateral rolling torque caused by gravity by distributing the robot's weight, thus keeping the robot stable when moving on slopes and preventing the wheeled structure from rolling due to gravitational torque when facing steep slopes. At the same time, this mechanism reduces the reliance on complex algorithms and sensors, improving control efficiency. In environments with small obstacles such as grass, gravel, and rocky slopes, the auxiliary mechanism 17 assists the robot in climbing or descending slopes by passively pushing obstacles, significantly improving the stability and movement efficiency of the snake robot on slopes and complex terrain.

[0046] Figure 5This is an exploded view of the torso unit in an embodiment of the present invention. A partition 46 is provided on the lower edge of the upper torso shell 24, facilitating wiring inside the upper torso shell 24. Retaining rings 57 are provided on both sides of the lower torso shell and inserted into grooves 49 on the upper edge of the lower torso shell; the two are connected by M3*5 screws 22. Two rollers 15 are located at both ends of the dual-axis DC motor 21, and the outer sides of the rollers 15 are fixed by shaft end fixing sleeves 14. A motor limiting structure is provided in the middle of the lower torso shell 16, and the dual-axis DC motor 21 is fixed within the motor limiting structure. Screw mounting blocks 19 are provided at the front and rear ends of the motor limiting structure, and windows are provided on the left and right sides of the motor limiting structure. The auxiliary mechanism includes an arc-shaped connector 52 and an extension plate 53. The arc-shaped connector 52 is located below the lower outer shell 16 of the torso and is connected to the screw mounting block 19 via four M3*10 screws 20. The arc-shaped connector 52 has a wheel seam 54, and the rollers 15 on both sides extend out of the window 51 and the wheel seam 54. The extension plate 53 is connected to the arc-shaped connector 52 and extends outward. The lowest point of the rollers 15 is lower than the lowest point of the auxiliary mechanism 17 (the auxiliary mechanism 17 does not touch the ground), ensuring that the tires contact the ground during movement and reducing wear on the auxiliary mechanism 17. The rotation of the dual-axis DC motor 21 drives the rotation of the rollers 15, realizing the forward drive of the torso.

[0047] Figure 6 This is a schematic diagram of the motor limiting structure in an embodiment of the present invention. The motor limiting structure includes a motor plane 50, two limiting plates 55, and four elastic limiting posts 56. The motor plane 50 is located in the middle of the inner part of the lower shell 16 of the torso, with two limiting plates 55 at the front and rear and four elastic limiting posts 56 on the left and right. The dual-axis DC motor 21 is placed flat on the motor plane 50, clamped at the front and rear by the two limiting plates 55 and on the left and right by the four elastic limiting posts 56, thus fixing the dual-axis DC motor.

[0048] The extension plate 53 described in this invention can be made into a foldable type or rotatedly connected with the arc-shaped connector 52, so that it can pass smoothly through narrow pipes or openings.

[0049] Figure 7 This is a schematic diagram of the snake head module in an embodiment of the present invention. The snake head module consists of a lidar 25, an onboard computer 28, a depth camera 32, a camera mounting bracket 31, and a torso unit 4.

[0050] Figure 8This is an exploded view of the snakehead module in this embodiment of the invention. The lidar 25 is mounted above the torso unit 4 using M3 screws. The onboard computer 28 is fixed to a partition 46 on the lower edge of the upper shell 24 of the torso using M2 screws. A bracket fixing end 27 is located at the front end of the torso unit. The camera connecting frame 31 is connected to the bracket fixing end 27 via two hand-tightening screws 30, allowing for vertical swinging freedom. Loosening the hand-tightening screws 30 allows for manual adjustment of the camera's pitch angle. The depth camera 32 is connected to the camera connecting frame 31 via M3*4 screws 29. The snakehead module is the central control system, containing sensors such as the lidar 25 and depth camera 32 to perceive environmental information, collect attitude data, build an environmental map, identify target content, and transmit this data to the onboard computer 28 via a USB interface. The onboard computer 28 processes the relevant data to control the rotation of the servos and motors, achieving motion control of the robot.

[0051] Figure 9 This is a schematic diagram of the snake-tail module in an embodiment of the present invention. The snake-tail module is a tracked structure, consisting of a snake-tail connector 33, a track bracket 34, a first fixed shaft 35, a track 36, a shaft end retaining ring 37, a single-axis DC motor 38, a second fixed shaft 39, a gear 40, a first sprocket 42, a second sprocket 41, and a baffle 43.

[0052] Figure 10 This is an exploded view of the snake-tail module in this embodiment of the invention. The snake-tail connector 33 is connected to the track bracket 34 by four M2*4 self-tapping screws 45. The snake-tail connector 33 is connected to the main and auxiliary rudder discs of the dual-axis servo motor of the previous snake body module by M3 screws. The track bracket 34 is equipped with sprocket 1 42 and sprocket 2 41, which are fixed to the track bracket 34 by fixing shaft 1 35 and fixing shaft 2 39, respectively. The single-axis DC motor 38 is fixed to the track bracket 34 by M3 screws. The output shaft of the single-axis DC motor 38 is connected to gear 40, and gear 40 meshes with the inner gear of sprocket 2 41. The internal space of the track bracket 34 is used to place components such as batteries, which are fixed by two baffles 43. The baffles 43 are fixed to the track bracket 34 by M4*6 screws 44. The track 36 meshes with the outer gears of sprocket 42 and sprocket 41. The rotation of the single-axis DC motor 38 causes the gear 40 to rotate, which in turn drives the sprocket 41, enabling the track 36 to engage and propel forward. This, in turn, drives the sprocket 42, propelling the track forward. The tracked structure, with its large ground contact area and low pressure, can adapt to complex terrains such as mud, sand, and gravel, avoiding getting stuck or slipping. Simultaneously, the track's anisotropic friction characteristics, mimicking the scales of a snake, optimize propulsion efficiency in complex terrain, distribute weight, and provide a wide support surface, significantly reducing the risk of center-of-gravity shift. This invention combines wheeled and tracked mechanisms, integrating the terrain adaptability of tracks with the high-speed characteristics of wheels, thus improving the stability and adaptability of the snake-like robot's movement.

[0053] Figure 11 This is a schematic diagram of the control system structure of the present invention. The control system can be divided into the following five parts: perception fusion layer, navigation planning layer, communication control layer, motion execution layer, and power management layer. The perception fusion layer consists of a depth camera, lidar, GNSS module, and IMU module, which acquires environmental information and its own pose information to perform preliminary perception fusion; the navigation planning layer consists of a computer and an onboard computer, which receives data from the perception fusion layer for analysis and decision-making to achieve path planning; the communication control layer consists of a Bluetooth module and a voice recognition module to achieve human-machine interaction control; the motion execution layer consists of a servo controller and several dual-axis servos, which receive instructions from the host computer and the main controller, send command sets through a serial bus to achieve motion execution of the servos, and simultaneously control dual-axis DC motors and single-axis DC motors to drive the drive wheel and tracks forward; the power management layer consists of a power supply and a power management module to provide stable power to the other four layers. The hardware circuit design adopts a modular approach, with each module connected to the onboard computer and the main controller through interface numbers. This design facilitates future expansion and upgrades, and facilitates the integration of newly added modules with the existing system. The snake robot software uses the Ubuntu 20.04 operating system and ROS1 noetic to implement motion control, environmental perception, mapping, path planning and communication functions.

[0054] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A modular snake-like robot suitable for complex terrain, characterized in that: It includes a snake head module, a snake tail module, and multiple snake body modules, as well as its control system; The snake body module consists of a torso unit and a joint unit. The joint unit uses two dual-axis servos and a cross-shaped orthogonal support structure to achieve two degrees of freedom of movement: left and right, and up and down. The torso unit drives rollers via dual-axis motors to propel the robot forward, and an auxiliary mechanism is located below the torso unit. The snake head module further integrates a lidar, depth camera, and onboard computer based on the snake body module. It uses sensors to perceive the environment and process data to control the robot's movement. The snake tail module adopts a tracked structure, suitable for traversing complex terrain. The snake head module, snake tail module, and snake body module are all connected to the control system. The torso unit includes an upper torso shell, a lower torso shell, a dual-axis DC motor, rollers, shaft end fixing sleeves, and auxiliary mechanisms. The upper and lower torso shells are semi-circular structures. The lower edge of the upper torso shell has a partition, the front end of the upper torso shell has a mounting block, the rear end of the upper torso shell has a connecting plate one, and the rear end of the lower torso shell has a connecting plate two. The lower sides of the upper torso shell have retaining rings that insert into grooves on the upper edge of the lower torso shell, and the two are connected by screws. Two rollers are located at both ends of the dual-axis DC motor, and the outer sides of the rollers are fixed by shaft end fixing sleeves. The lower torso shell has a motor limiting structure in the middle inside, and the front and rear ends of the motor limiting structure have... The screw mounting block and the motor limiting structure have windows on both sides. The dual-axis DC motor is fixed inside the motor limiting structure. The auxiliary mechanism includes an arc-shaped connector and an extension plate. The arc-shaped connector is located below the lower shell of the torso. The arc-shaped connector is connected to the screw mounting block by bolts. The arc-shaped connector has wheel slots. Rollers on both sides extend out of the windows and wheel slots. The extension plate is connected to the arc-shaped connector and extends outward. The lowest point of the roller is lower than the lowest point of the auxiliary mechanism. The auxiliary mechanism generates a reverse torque to counteract the lateral rolling torque caused by gravity by distributing the robot's weight, so that the robot remains stable when moving on a slope and avoids lateral rolling due to gravity torque when the wheeled structure faces a steep slope. The motor limiting structure includes a motor plane, two limiting plates, and four elastic limiting posts. The motor plane is located in the middle of the lower shell of the torso, with two limiting plates at the front and back and four elastic limiting posts on the left and right. The dual-axis DC motor is placed flat on the motor plane, clamped by the two limiting plates at the front and back and by the four elastic limiting posts on the left and right, thus fixing the dual-axis DC motor.

2. A modular snake-like robot suitable for complex terrain according to claim 1, characterized in that: The joint unit includes a dual-axis servo motor 1, a dual-axis servo motor 2, a main servo disk, a secondary servo disk, a snake-body connector, and a cross-shaped orthogonal bracket. The front end of the cross-shaped orthogonal bracket is connected to the output shaft of the dual-axis servo motor 1, the rear end of the cross-shaped orthogonal bracket is connected to the dual-axis servo motor 2, the snake-body connector is connected to the output shaft of the dual-axis servo motor 2, and a mounting groove is provided on the top of the snake-body connector.

3. A modular snake-like robot suitable for complex terrain according to claim 2, characterized in that: Adjacent torso units are connected by mounting blocks at the front of the upper shell of the torso and mounting slots on the snake-body connector. Connecting plate one and connecting plate two are connected to dual-axis servo motor one. The torso units and joint units are connected by self-tapping screws.

4. A modular snake-like robot suitable for complex terrain according to claim 1, characterized in that: The snake head module includes a snake body module, a lidar, an onboard computer, a depth camera, and a camera mounting bracket. The lidar is located above the torso unit, the onboard computer is located above the partition, and a bracket fixing end is located at the front end of the torso unit. The camera mounting bracket is connected to the bracket fixing end by two hand-tightening screws, and the depth camera is connected to the camera mounting bracket.

5. A modular snake-like robot suitable for complex terrain according to claim 1, characterized in that: The snake-tail module is a tracked structure, including a snake-tail connector, a track bracket, a fixed shaft one, a track, a shaft end retaining ring, a single-axis DC motor, a fixed shaft two, a gear, a sprocket one, a sprocket two, and a baffle. The snake-tail connector is connected to the track bracket, and the front end of the snake-tail connector is connected to the dual-axis servo motor corresponding to the previous snake-body module. The track bracket is equipped with sprocket one via fixed shaft one and sprocket two via fixed shaft two. The single-axis DC motor is fixed on the track bracket, and the output shaft of the single-axis DC motor is connected to the gear. The gear meshes with the inner gear of sprocket two. The baffle is located on the outside of the track bracket, and the track meshes with the outer gears of sprocket one and sprocket two.

6. A modular snake-like robot suitable for complex terrain according to claim 1, characterized in that: The control system includes a perception fusion layer, a navigation planning layer, a communication control layer, a motion execution layer, and a power management layer. The perception fusion layer consists of a depth camera, lidar, GNSS module, and IMU module, which acquires environmental information and its own pose information to perform preliminary perception fusion. The navigation planning layer consists of a computer and an onboard computer. It receives data from the perception fusion layer, analyzes and makes decisions to achieve path planning. The communication control layer consists of a Bluetooth module and a voice recognition module, enabling human-computer interaction control; The motion execution layer consists of a servo controller and several dual-axis servos. It receives instructions from the host computer and the main controller, sends command sets through a serial bus, and realizes the motion execution of several dual-axis servos. At the same time, the motion execution layer controls dual-axis DC motors and single-axis DC motors to drive the drive wheel and track forward. The power management layer consists of power supplies and power management modules, providing stable power to the four layers mentioned above.

7. A modular snake-like robot suitable for complex terrain according to claim 6, characterized in that: The control system uses the Ubuntu 20.04 operating system and implements motion control, environmental perception, mapping, path planning and communication functions through ROS1 noetic.

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