Three-degree-of-freedom joint module and snakelike robot

Abstract

The invention provides a three-degree-of-freedom joint module and a snakelike robot. The joint module comprises a front connecting disc, a front bin, a rear bin and a rear connecting disc. A first motor and a second motor are arranged in the front bin, and a third motor is arranged in the rear bin; a main controller is arranged on the front connecting disc, and a spring probe connector is arranged on the rear connecting disc; the first motor drives the front connecting disc to rotate around a first rotating axis relative to the front bin, so that a first radial degree of freedom is formed, and the angle range is-90 degrees to 90 degrees; a second motor drives the front bin to rotate around a second rotation axis relative to the rear bin to form a second axial degree of freedom, and infinite continuous rotation is supported through a conductive slip ring; the third motor drives the rear connecting disc to rotate around a third rotating axis relative to the rear bin, a third radial freedom degree is formed, and the angle range is-90 degrees to 90 degrees. The axial freedom degree of the joint module can be infinitely rotated, local continuous rotating motion between the modules can be achieved, and therefore the problems that the axial freedom degree of an existing snake-shaped robot is limited, and wheel type motion cannot be formed are solved.

Description

Technical Field

[0001] This application relates to the field of biomimetic robots, specifically to a three-degree-of-freedom joint module and a snake-like robot. Background Technology

[0002] Snake robots are biomimetic robots with highly redundant degrees of freedom in their body structure. Due to their small cross-sectional area, flexible and reliable gait, and strong adaptability to complex terrain, snake robots are particularly suitable for tasks requiring confined space operation, such as pipeline exploration and landslide rescue. Based on their locomotion methods, snake robots can be divided into two categories: "passive skin" and "active skin." "Passive skin" snake robots, such as the single-degree-of-freedom modular snake robot disclosed in patent CN106660203B, move in complex terrain by mimicking various gaits of a snake. However, because these snake robots rely on friction between their outer surface and the environment for propulsion, their locomotion efficiency is low and their movement speed is slow. "Active skin" snake robots, such as the amphibious snake robot with a helical drive disclosed in patent CN111687823A, generate propulsion through rotatable wheels on their drive surface and then use other joints to change the overall robot configuration to achieve efficient movement. This type of movement uses the gait of a non-biological snake, so the "active skin" snake robot has poor mobility and low adaptability to complex terrain.

[0003] Application content In view of the deficiencies in the prior art, the purpose of this application is to provide a three-degree-of-freedom joint module and a novel snake robot composed thereof.

[0004] In a first aspect, this application provides a three-degree-of-freedom joint module, comprising a front connecting plate, a front compartment, a rear compartment, and a rear connecting plate connected in sequence; the front compartment is provided with a first motor and a second motor, and the rear compartment is provided with a third motor; The first motor drives the front connecting plate to rotate relative to the front compartment around the first rotation axis, forming the first radial degree of freedom, with an angle range of -90° to 90°. The second motor drives the front compartment to rotate relative to the rear compartment around the second rotation axis, forming the second axial degree of freedom, and supports infinite continuous rotation through a conductive slip ring; The third motor drives the rear connecting plate to rotate relative to the rear compartment around the third rotation axis, forming the third radial degree of freedom, with an angle range of -90° to 90°.

[0005] Optionally, by changing the joint angle of the second axial degree of freedom, the spatial angle between the first rotation axis and the third rotation axis can be changed accordingly, ranging from 0 to 180 degrees.

[0006] A second aspect of this application provides a snake-like robot based on a three-degree-of-freedom joint module, comprising a head module, a joint module, a tail module, and a power signal bus connected in sequence; the head module is used to collect environmental information; multiple joint modules are connected in series between the head module and the tail module; the power signal bus runs through and connects each module, and is led out from the tail module.

[0007] Optionally, the head module includes a speaker, a camera, a light, and a microphone.

[0008] Optionally, the tail module is provided with a tail conductive slip ring, which allows the bus lines inside the tail module to rotate infinitely relative to the power signal bus, thus preventing the power signal bus from becoming tangled or knotted.

[0009] Optionally, adjacent joint modules are connected via the connector; The spatial angle between the third rotation axis of the previous joint module and the first rotation axis of the next joint module is 90 degrees. The mechanical connection angle between adjacent joint modules can be adjusted, with selectable values ​​of 0 degrees and 90 degrees.

[0010] Optionally, the second axial degree of freedom of each joint module is locked, so that the rotation axes of the first radial degree of freedom and the second axial degree of freedom maintain a 90° spatial angle; at this time, all radial degrees of freedom inside the robot are orthogonal to each other, that is, the rotation axes of two adjacent radial degrees of freedom are perpendicular to each other, realizing the robot's passive skin mode.

[0011] Optionally, every two adjacent joint modules constitute a basic rotational unit; in each basic rotational unit, the radial degrees of freedom of the joint modules are locked at zero, and the rotation axes of the second axial degrees of freedom of two adjacent joint modules within the unit are arranged in a coaxial direction; multiple basic rotational units are connected in series to jointly form the main structure of the robot. This configuration forms the robot's active skin gait pattern.

[0012] Optionally, it also includes a helical drive housing for enabling land propulsion; The helical drive housing is fixed between two adjacent joint modules; By setting the second motor speed of the previous joint module to n and the second motor speed of the next joint module to -n, the helical drive housing is made to rotate at a constant speed.

[0013] Optionally, the spiral directions of the spiral drive housings mounted on adjacent basic rotating units are different from each other, and they are distributed in an alternating pattern of left-handed, right-handed, and left-handed spirals.

[0014] Optionally, it also includes an underwater propulsion hull for realizing underwater propulsion; the underwater propulsion hull is installed between two adjacent joint modules; by setting the second motor speed of the preceding joint module to n and the second motor speed of the following joint module to -n, the underwater propulsion hull rotates at a constant speed.

[0015] The three-degree-of-freedom joint module provided in this application can achieve local continuous rotational motion between modules because the axial degree of freedom of the joint module can rotate infinitely, thereby solving the problem that the axial degree of freedom of existing snake robots is limited and they cannot form wheel-like motion.

[0016] Multiple three-degree-of-freedom joint modules can be connected end to end. By coordinating the rotation of the joint modules, the robot can both form a wheel-like propulsion motion and maintain a biomimetic snake gait. This achieves the goal of simultaneously taking into account speed and adaptability to complex terrain, and solves the limitations of existing snake robots with "active skin" and "passive skin".

[0017] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0018] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a joint module structure according to an exemplary embodiment; Figure 2 This is a half-sectional view of a joint module structure according to an exemplary embodiment; Figure 3 This is a schematic diagram of the overall structure of a robot according to an exemplary embodiment; Figure 4 This is a schematic diagram of the header module structure according to an exemplary embodiment; Figure 5 This is a schematic diagram of the tail module structure according to an exemplary embodiment; Figure 6 This is a half-sectional view of the tail module structure according to an exemplary embodiment; Figure 7 This is a schematic diagram illustrating the connection between joint modules according to an exemplary embodiment; Figure 8 This is a block diagram of the electrical structure of a tail-end hot-swappable plug according to an exemplary embodiment; Figure 9 This is a block diagram of the electrical structure of a main controller according to an exemplary embodiment; Figure 10 This is a schematic diagram of a helical drive housing structure according to an exemplary embodiment; Figure 11 This is a schematic diagram of the mounting of a helical drive housing according to an exemplary embodiment; Figure 12 This is a schematic diagram of the helical cross-section of a helical drive housing according to an exemplary embodiment; Figure 13 This is a schematic diagram of an underwater propulsion hull structure according to an exemplary embodiment; Figure 14 This is a front view of an underwater propulsion hull according to an exemplary embodiment; In the diagram: 1 Head module; 2 Joint module; 3 Tail module; 4 Power signal bus; 5 Speaker mounting hole; 6 Camera mounting hole; 7 Lighting mounting hole; 8 Microphone mounting hole; 9 Positioning threaded hole; 10 Main controller; 11 Front cover plate; 12 Rear swivel joint; 13 Rear cover plate; 14 Rear connecting plate; 15 Rear motor compartment; 16 Front swivel joint; 17 Front motor compartment; 18 Front rotating plate; 19 Front through hole; 20 First motor; 21 Second motor; 22 Conductive slip ring; 23 Third motor; 24 Spring probe connector; 25 Plug; 26 Tail hot-swappable plug plate; 27 Tail through hole; 28 Tail conductive slip ring; 29 Bus wiring hole; 30 First rotating axis; 31 Third rotating axis; 32 Second rotating axis; 33 Set screw; 34 100Mbps Ethernet cable; 35 Power cord; 36 36V hot-swappable circuit; 37 38 First Ethernet port; 39 Three-port Ethernet switch; 40 Nine-axis inertial measurement unit; 41 Microcontroller; 42 CAN transceiver circuit; 43 +5V to +1.8V step-down circuit; 44 +5V to +3.3V step-down circuit; 45 +36V to +5V step-down circuit; 46 Second Ethernet port; 47 CAN bus; 48 Helical drive housing; 59 First helical housing; 50 Helical housing mounting holes; 51 Second helical housing; 52 Helical cross-section; 53 Underwater propulsion housing; 54 Propulsion housing mounting holes. Detailed Implementation

[0019] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0020] In existing technologies, the axial degrees of freedom of some joint modules constituting snake robots are restricted, thus limiting the movement of the snake robot. To address this problem, this application proposes a three-degree-of-freedom joint module.

[0021] like Figure 1 As shown in some embodiments of this application, a three-degree-of-freedom joint module includes a front connecting plate, a front compartment, a rear compartment, and a rear connecting plate connected in sequence; the front compartment is provided with a first motor with its output shaft in the vertical direction and a second motor with its output shaft in the horizontal direction; the rear compartment is provided with a third motor with its output shaft in the vertical direction; the output shafts of the three motors correspond to form a first rotation axis, a second rotation axis, and a third rotation axis. Specifically, the main controller is integrated on the front connecting plate, and the spring probe connector is provided on the rear connecting plate. The spring probe connector is used to form an elastic electrical connection with the electrical contact end face of the previous module when adjacent modules are docked. The connector includes multiple conductive probes with spring reset, which can automatically adapt to assembly errors and realize reliable conduction of power supply, control signals and communication bus.

[0022] The first motor drives the front connecting plate to rotate relative to the front compartment around the first rotation axis, forming the first radial degree of freedom, with a rotation angle range of -90° to +90°. The second motor drives the front compartment to rotate relative to the rear compartment around the second rotation axis, forming the second axial degree of freedom, and achieves infinite continuous rotation through a conductive slip ring.

[0023] Specifically, a conductive slip ring, also known as a "rotary electrical connector" or "slip ring," is an electromechanical component that can continuously transmit electrical signals and power between a fixed part and a rotating part.

[0024] A conductive slip ring is provided on the second rotation axis to realize continuous power and signal transmission between the rear compartment and the front compartment. The conductive slip ring includes a stator part fixed to the rear compartment and a rotor part that rotates synchronously with the front compartment. The two are coupled by sliding contact to support the front compartment to rotate continuously relative to the rear compartment without limit.

[0025] The third motor drives the rear connecting plate to rotate relative to the rear compartment around the third rotation axis, forming the third radial degree of freedom, with a rotation angle range of -90° to +90°.

[0026] In the above embodiments of this application, because the axial degree of freedom of the joint module can rotate infinitely, local continuous rotational motion between modules can be realized, thereby solving the problem that the axial degree of freedom of existing snake robots is limited and cannot form wheel-like motion.

[0027] To facilitate installation and connection, in some specific embodiments of this application, the front compartment is divided into a front rotary joint and a front motor compartment, and the rear compartment is divided into a rear rotary joint and a rear motor compartment. The stator of the first motor is connected to the front compartment, and the rotor is connected to the front connecting plate; the front compartment and the front connecting plate are connected via the first motor. The stator of the third motor is connected to the rear compartment, and the rotor is connected to the rear connecting plate; the rear compartment and the rear connecting plate are connected via the third motor. Figure 1 and Figure 2 As shown, the joint module may include: a main controller 10, a spring probe connector 24, a front connecting plate 18, a front cover plate 11, a front motor compartment 17, a front swivel joint 16, a rear connecting plate 14, a rear cover plate 13, a rear motor compartment 15, and a rear swivel joint 12.

[0028] Specifically, in the joint module housing, the front cover plate 11 and the front connecting plate 18 form an L-shaped structure, together constituting a rotatable front end assembly; the first motor 20 is fixed in the front motor compartment 17, and its output shaft is connected to the front connecting plate 18; when the motor is running, it drives the front connecting plate and the front cover plate to rotate around the first rotation axis 30, forming the first radial degree of freedom.

[0029] The stator of the second motor is fixed to the front rotating section, and the output shaft is connected to the rear rotating section by screws. When the motor is running, it drives the rear rotating section to rotate relative to the front rotating section around the second rotation axis. The rotor part of the conductive slip ring is fixedly connected to the rear rotating section to realize rotational power supply and communication.

[0030] The rear cover plate 13 and the rear connecting plate 14 form an L-shaped structure, together constituting a rotatable rear end assembly. The third motor 23 is fixed inside the rear motor compartment 15, and its output shaft is connected to the rear connecting plate 14. When the motor moves, it drives the rear connecting plate and the rear cover plate as a whole to rotate around the third rotation axis 31, forming a third radial degree of freedom.

[0031] The main controller is connected to the front connecting plate by screws, and the spring probe connector is connected to the rear connecting plate by screws.

[0032] The above embodiments of this application demonstrate the structure of a complete joint module and its connection method, which is practical.

[0033] In order to ensure that the two joint modules fit together and connect, some specific embodiments of this application, such as Figure 2 As shown, the rear connecting plate 14 has multiple circumferentially distributed insertion ends 25 on its outer periphery, and each insertion end is provided with a threaded hole; the front connecting plate 18 has a corresponding recess, and the recess is provided with a through hole 19; when adjacent modules are connected, the insertion end is inserted into the recess, and the bolt passes through the through hole and is screwed into the threaded hole to achieve a tight connection.

[0034] By adjusting the joint angle of the second axial degree of freedom, the spatial angle between the first and third rotation axes can be changed, with a theoretical adjustment range of 0° to 180°. The joint angle refers to the relative rotation angle between the front and rear rotary joints. However, in a mechanical connection structure using a plug-and-notch fit, the assembly angle of adjacent modules is limited to several discrete states. In this case, the spatial angle between the first and third rotation axes can only be configured as 0° or 90°. Different spatial angle configurations correspond to different overall configurations and can be used to switch the motion patterns of the snake robot.

[0035] Based on the same technical concept, some embodiments of this application provide a snake-like robot with a three-degree-of-freedom joint module, such as... Figure 3 As shown, it mainly consists of a head module 1, joint modules 2, tail module 3, and a power signal bus 4. The head module 1 is used to collect environmental information; multiple joint modules 2 are connected in series between the head module and the tail module; the power signal bus 4 runs through and connects all modules, and is led out from the tail module 3.

[0036] Specifically, the number of joint modules can be changed according to different uses and application scenarios. One joint module has three rotational degrees of freedom. Therefore, the total degrees of freedom of the machine is three times the number of joint modules.

[0037] For example, a snake-like robot consists of a head module, eight joint modules, a tail module, and a power signal bus.

[0038] The robot in the above embodiments of this application, by coordinating the axial degrees of freedom rotation between joint modules, enables the robot to both form a wheel-like propulsion motion and maintain a biomimetic snake gait, achieving the goal of simultaneously taking into account speed and adaptability to complex terrain, and solving the limitations of existing "active skin" and "passive skin" snake robots.

[0039] To better obtain environmental information, some embodiments of this application, such as Figure 4 As shown, the head module is designed with speaker mounting holes, camera mounting holes, lighting mounting holes, and microphone mounting holes, and is connected to the next joint module through four positioning threaded holes.

[0040] In the embodiments described above, the head module serves as the robot's perception and interaction front end, integrating visual, auditory, and lighting functions. It acquires environmental images through a camera, collects sound through a microphone, provides ambient lighting through a lamp, and enables voice interaction through a speaker. Simultaneously, it connects to the main structure via a mechanical interface, making it a crucial component for the robot to acquire external information and interact with its environment.

[0041] To better implement wiring, some embodiments of this application, such as Figure 5 and Figure 6 As shown, the tail module is designed with a tail hot-swappable insert plate 26, a tail conductive slip ring 28, and a bus routing hole 29. The tail hot-swappable insert plate 26 and the tail conductive slip ring 28 are connected to the tail module 3 by screws. The tail module 3 is connected to the preceding joint module 2 by screws through the tail through hole 27. The power signal bus 4 passes through the bus routing hole 29 and is soldered to the tail conductive slip ring 28.

[0042] It is worth noting that during gait execution, the entire device may rotate around its own axis, causing the power signal bus 4 to become tangled and knotted. Therefore, a tail conductive slip ring is designed in the tail module. This design allows the internal bus of the tail module to rotate indefinitely relative to the power signal bus, preventing the power signal bus from becoming tangled and knotted.

[0043] To achieve greater degrees of freedom, snake-like robots employ at least two joint modules. Therefore, to better facilitate the connection of snake-like robots, some specific embodiments of this application, such as... Figure 7 The connection structure shown, The front connecting plate 18 is provided with a front cover plate 11, and four notches are evenly distributed on the outer periphery of the front cover plate 11; the rear connecting plate 14 is provided with a rear cover plate 13, and four insertion ends 25 that match the notches are evenly distributed on the outer periphery of the rear cover plate 13; when adjacent joint modules 2 are connected, the rear connecting plate 14 of the front module is inserted into the front connecting plate 18 of the rear module, and mechanical connection and fixation are achieved through the cooperation of the insertion ends 25, the notches and screws; the insertion ends 25 and the notches are symmetrically arranged at 90° intervals along the circumference, so that docking can be completed in two relative orientations: the third rotation axis 31 of the front module is parallel or perpendicular to the first rotation axis 30 of the rear module; the insertion ends 25, the notches and the screws for fastening together constitute the connector assembly. Figure 7 The space angle between the third rotation axis and the first rotation axis is 90 degrees.

[0044] The above embodiments of this application realize different orientational relationships between the front and rear modules, which can be applied to different scenarios and uses.

[0045] In addition to achieving the mechanical connection between two adjacent modules, an electrical connection between them is also required. In some specific embodiments of this application, the power signal bus 4 is a six-core wire, of which two are power lines 35, namely +36V and ground; the other four are 100Mbps Ethernet cables 34. The power signal bus 4 is first connected to the tail hot-swappable board 26 of the tail module 3. The tail hot-swappable board 26 is designed with a set of 36V hot-swappable circuits 36, which extend the power-on time of the whole machine's electronic control system to tens of milliseconds, suppress the surge current at the moment of power-on, and enable the whole machine to support power hot-swapping. At the same time, the tail hot-swappable board 26 is designed with six pads, corresponding to the power lines 35 and the 100Mbps Ethernet cables 34, respectively, to establish an electrical connection with the spring probe connector 24 on the preceding joint module 2.

[0046] Furthermore, each joint module 2 has a spring probe connector 24 equipped with six spring probes for establishing an electrical connection with the next joint module 2 or tail module 3. The main controller 10 of each joint module 2 establishes an electrical connection with the spring probe connector 24 via a bus. The main controller 10 is designed with a +36V to +5V step-down circuit 44, a +5V to +3.3V step-down circuit 43, and a +5V to +1.8V step-down circuit 42. Specifically, the +36V to +5V step-down circuit 44 powers the CAN (Controller Area Network) bus transceiver circuit 41; the +5V to +3.3V step-down circuit 43 powers the microcontroller 40 and the three-port Ethernet switch 38; and the +5V to +1.8V step-down circuit 42 powers the nine-axis inertial measurement unit 39. The main controller 10 is also equipped with a three-port Ethernet switch 38. Its first Ethernet port 37 establishes a local area network (LAN) connection with the preceding joint module 2 via a 100Mbps Ethernet cable 34; its second Ethernet port 45 establishes a LAN connection with the following joint module 2 via the same 100Mbps Ethernet cable 34; and it transmits data to the microcontroller 40 via RMII (Reduced Media Independent Interface) for simplified media independence. The nine-axis inertial measurement unit 39 connects to the microcontroller 40 via I... 2 The C (Inter-Integrated Circuit) bus protocol is used for data transmission, providing attitude information to the joint module 2. The microcontroller 40 sends and receives data to and from the CAN bus 46 via the CAN transceiver circuit 41. The first motor 20, the second motor 21, and the third motor 23 on the joint module 2 are all electrically connected to the CAN bus 46, thus completing data transmission with the microcontroller 40. Similarly, the main controller 10 is also designed with six pads, corresponding to the power line 35 and the 100Mbps Ethernet cable 34, respectively, to establish electrical connections with the spring probe connector 24 on the previous joint module 2.

[0047] In the embodiments described above, this structure achieves mechanical connection between adjacent modules while realizing electrical connection through a six-core power signal bus; the rear hot-swappable plug provides power surge suppression and hot-swappable functions to ensure system power-on safety; the main controller of each joint module interfaces with the bus through a spring probe connector to complete power step-down distribution and data communication; power is supplied to each component through a three-stage step-down circuit, and network connection between modules is realized using a three-port Ethernet switch; in conjunction with the CAN bus and a nine-axis inertial measurement unit, motor control, attitude perception and data transmission are realized, thereby ensuring stable power and signal transmission and plug-and-play scalability when multiple modules are connected in series.

[0048] Based on the joint module structural design, the snake robot of this application can break through the inherent boundary between "active skin" and "passive skin" and realize the function of "variable skin". This design enables the system to combine the advantages of both types of snake robots, maintaining good flexibility and adaptability in complex terrain, and achieving efficient propulsion under suitable conditions.

[0049] In this context, "active skin" refers to a structural form on the outer surface of a snake-like robot that possesses active driving capabilities. Snake robots with active skin move by the power output of a drive unit, rather than relying on passive friction between the robot body and the ground. In active skin mode, the rotating structure of this application can actively generate tangential or normal thrust to achieve overall robot propulsion.

[0050] Passive skin refers to a structural form of a snake-like robot whose outer surface lacks active driving capability. Passive skin snake-like robots mimic the natural gait of snakes, relying primarily on environmental friction for propulsion. In passive skin mode, the movement of this application mainly depends on the coordinated swinging of the robot's joints, achieving forward movement or turning through the frictional difference between the robot's deformation and the ground.

[0051] In some specific implementations, by coordinating the axial rotational degrees of freedom of adjacent joint modules, the body can form a continuous rolling motion similar to a "wheel", thereby possessing a highly efficient propulsion capability close to that of an "active skin" snake robot.

[0052] Specifically, when the robot performs an "active skin" gait, the second axial degrees of freedom inside adjacent joint modules 2 coordinate their movements while keeping their radial degrees of freedom at zero. At this time, the two adjacent axial degrees of freedom can jointly form a cylindrical rotational structure, thereby giving this part of the robot body wheel-like rotational characteristics.

[0053] Furthermore, since the robot is composed of eight articulated joint modules 2 connected in series, adjacent two modules can be paired to form a set of cylindrical structures (this cylindrical structure can also be called a basic rotational unit, specifically referring to a structural unit composed of two adjacent joint modules working together to simulate wheel rotation), thus forming four sets of wheel-like basic rotational units overall. With the coordinated drive of these four sets of wheel-like basic rotational units, the robot can achieve continuous rolling motion similar to that of a wheeled robot, improving its movement efficiency and speed on flat terrain. The radial degrees of freedom between adjacent wheel-like units are used to control the overall configuration of the robot, determining its direction of travel.

[0054] It should be noted that during the "active skin" gait, there are no restrictions on the angles of the first and third rotation axes; they can be 0 degrees, 90 degrees, or other angles.

[0055] In some specific embodiments of this application, a wheeled control mode is not adopted, allowing the robot to mimic the natural gait of a biological snake and possess the terrain adaptability of a "passive skin" snake-like robot.

[0056] Specifically, when the robot performs a "passive skin" gait, the second axial degree of freedom of each joint module 2 is locked, and the spatial angle between the rotation axes of the first and third radial degrees of freedom within the module is maintained at 90°. At this time, the radial degrees of freedom within the entire robot are orthogonal to each other, that is, the rotation axes of two adjacent radial degrees of freedom are perpendicular to each other. In "passive skin" mode, the robot can perform biomimetic gaits such as meandering, rolling, and lateral sliding to adapt to rugged terrain.

[0057] The above embodiments of this application adopt a "variable skin" design. By coordinating the axial degrees of freedom rotation between joint modules, the robot can form a wheel-like propulsion motion and maintain a biomimetic snake gait. This achieves the goal of simultaneously taking into account speed and adaptability to complex terrain, and solves the limitations of "active skin" and "passive skin" snake robots in the prior art.

[0058] To further improve the adaptability of the snake robot to various terrain environments, some specific embodiments of this application include a helical drive housing 47, which, for ease of installation, is divided into a first helical housing 48 and a second helical housing 50. The helical drive housing 47 has four helical housing mounting holes 49. During installation, the set screws are screwed into the mounting holes 49 to fix the helical drive housing 47 to two adjacent joint modules 2.

[0059] Specifically, the helical drive housing 47 covers the rear connecting plate 14, rear cover plate 13, rear motor compartment 15 and rear swivel joint 15 of the previous joint module 2, and covers the front connecting plate 18, front cover plate 11, front motor compartment 17 and front swivel joint 16 of the next joint module 2.

[0060] During operation, by setting the speed of the second motor 21 of the preceding joint module 2 to n and the speed of the second motor 21 of the following joint module 2 to -n, a constant-speed rotation of the helical drive housing 47 can be achieved. The helical cross-section 51 of the helical drive housing 47 adopts a rounded corner design to meet the requirement of maintaining frictional propulsion even in smooth terrain scenarios.

[0061] It is worth noting that the spiral direction of the spiral drive housing can be divided into left-handed and right-handed specifications. Spiral drive housings with different spiral cross-sectional parameters and pitch parameters can also be designed according to different application scenarios. The spiral drive housing is suitable for "active skin" gait patterns.

[0062] Furthermore, to achieve amphibious capability, some specific embodiments of this application include an underwater propulsion hull 52. The underwater propulsion hull 52 has four propulsion hull mounting holes 53 for threaded connection with the joint module 2. The underwater propulsion hull 52 has three propeller blades for generating propulsion underwater.

[0063] Specifically, the underwater propulsion shell 52 covers the rear connecting plate 14 and rear cover plate 13 of the previous joint module 2, and covers the front connecting plate 18, front cover plate 11, front motor compartment 17 and front swivel joint 16 of the next joint module 2.

[0064] During operation, by setting the speed of the second motor 23 of the preceding joint module 2 to n and the speed of the second motor 23 of the following joint module 2 to -n, a constant-speed rotation of the underwater propulsion hull 52 can be achieved. This underwater propulsion hull is also suitable for "active skin" gait modes.

[0065] The embodiments described above in this application, by adding a helical drive shell and an underwater propulsion shell to the cooperative rotation part of the multi-joint module, enable the robot to move in various terrain environments such as gliding on land and propulsion in water, thereby significantly improving the diversity of movement modes and environmental adaptability.

[0066] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0067] The following examples and comparative examples will be used to further illustrate this application in order to better understand the above-mentioned technical solutions of this application. It should be understood that the following are only some examples and are not intended to limit this application.

[0068] like Figure 1As shown, this application consists of four parts: a head module 1, a joint module 2, a tail module 3, and a power signal bus 4. The head module 1 has multiple device mounting holes, primarily for mounting devices used to collect environmental information; it connects to the next joint module 2 via four positioning threaded holes, preferably M2 hexagon socket head cap screws. The joint module 2 is the foundation for the robot's movement in space, integrating actuators, controllers, and sensors. It can execute motion commands sent from the host computer and feedback its own sensor data. The joint module 2 has two radial rotational degrees of freedom and one axial rotational degree of freedom. The radial rotational degree of freedom has angular limitations, while the axial rotational degree of freedom has no angular limitations. The tail module 3 is the hub for power and signal input to the robot, containing a circuit board with a hot-swappable circuit, giving the application hot-swappable power supply capabilities. Finally, the power signal bus 4 provides the application with +36V power and a 100Mbps Ethernet bus. It is a six-core cable with a pair of male and female aviation connectors for easy connection and disconnection between the main body of the power signal bus 4 and the tail module 3.

[0069] like Figure 2 As shown, the head module 2 is cylindrical in shape, with a diameter of 72.5 mm and a length of 75 mm. The front of the head module 1 has speaker mounting holes 5, camera mounting holes 6, lighting mounting holes 7, and microphone mounting holes 8 for mounting corresponding environmental information acquisition devices. The rear has positioning threaded holes 9, preferably for screwing in M2 socket head cap screws for mounting to the next module. The head module 2 can be manufactured using additive manufacturing technology, with materials such as nylon or polylactic acid; alternatively, it can be machined using CNC machining technology, with materials such as aluminum alloy.

[0070] like Figure 3 and Figure 4As shown, when all joint angles are in their initial state, joint module 3 is cylindrical with a diameter of 72.5 mm and a length of 205 mm. A main controller 10 is located at the front end of each joint module 3; its specific implementation method will be described later. A spring probe connector 24 is located at the rear end to receive power and signals from the next module. The spring probe connector 24 is a printed circuit board with spring probes soldered on. The spring probes are preferably surface-mount or plug-in type, gold-plated or nickel-plated, and their working height depends on the distance between the spring probe connector 24 and the printed circuit board on the next module. The surface covering parts of joint module 3 include a front connecting plate 18, a front cover plate 11, a front motor housing 17, a front swivel joint 16, a rear swivel joint 12, a rear motor housing 15, a rear cover plate 13, and a rear connecting plate 14. These surface covering parts are designed with threaded holes and through holes, preferably connected with M2 screws. These surface covering parts can be manufactured using additive manufacturing technology or CNC machining technology. Inside the joint module 3, a first motor 30, a second motor 32, and a third motor 23 are arranged, providing the module with a first radial degree of freedom, a second axial degree of freedom, and a third radial degree of freedom, respectively. The rotation range of the first and third radial degrees of freedom is ±90°. The design of the conductive slip ring 22 allows relative rotation between the two wiring sections within the module, thus making the rotation angle of the second axial degree of freedom unrestricted. The aforementioned drive device is preferably a servo DC harmonic geared motor, which has a large reduction ratio, smooth operation, and a central control shaft for convenient wiring. In a preferred embodiment, the motor's rated torque range is 1-5 N·m, and its rated speed is 45 rpm to meet the module's drive requirements. The aforementioned conductive slip ring 22 is preferably a 12-channel miniature flange conductive slip ring, which is convenient to fix inside the module and occupies as little space as possible. The 12 channels also facilitate power and communication wiring requirements. In a preferred embodiment, each channel of the conductive slip ring has a rated current of 2A, a rated voltage of 220V, and an electrical noise of 10mΩ at 10 rpm. The types and specifications of the equipment are not limited to the above range, and those skilled in the art can make substitutions according to actual needs.

[0071] like Figure 5 and Figure 6 As shown, the tail module 3 is cylindrical in shape, with a diameter of 72.5 mm and a length of 45 mm. A hot-swappable tail plate 26 is located at the front end of the tail module 3. Figure 8As shown, this is a printed circuit board with a hot-swappable MOSFET circuit. The MOSFET is preferably a P-channel MOSFET; in a preferred embodiment, the drain-source voltage of the MOSFET is 40V, the continuous drain current is 6A, and the time constant of the hot-swappable circuit is approximately 36ms. The tail module 3 has through-holes 27 around its perimeter for threaded connection to the previous module. A tail conductive slip ring 28 is arranged inside the tail module 3 to prevent the power signal bus 4 from tangling during gait. A bus routing hole 29 is provided at the rear end of the tail module 3 to facilitate the passage of the power signal bus 4.

[0072] like Figure 7 As shown, adjacent joint modules 2 are mechanically connected by four set screws 33, preferably M2 socket head cap screws. Depending on the application scenario, when establishing the connection, the spatial angle between the third radial degree of freedom of the preceding joint module 2 and the first degree of freedom of the following joint module 2 can preferably be 0° or 90°.

[0073] like Figure 9As shown, the main controller 10 is a printed circuit board containing module driver control circuitry, host computer communication circuitry, and related power conversion circuitry. The input and output cables for the main controller 10 are a +36V power supply and a 100Mbps Ethernet bus, respectively. The +36V power supply powers the three motors in the module; the +36V to +5V step-down circuit 44 steps down the +36V power supply to +5V for the CAN transceiver circuit 41; the +5V to +3.3V step-down circuit 43 steps down the +5V power supply to +3.3V for the microcontroller 40 and the three-port Ethernet switch 38; and the +5V to +1.8V step-down circuit 42 steps down the +5V power supply to +1.8V for the nine-axis inertial measurement unit 39. The microcontroller 10 is preferably a microcontroller chip equipped with peripheral resources such as I2C, CAN, and Ethernet, with a high main frequency and large SRAM; in a preferred embodiment, the microcontroller 10 can be an STM32 series microcontroller chip. The microcontroller 10 communicates with the CAN transceiver chip in the CAN transceiver circuit 41 via its internally integrated CAN controller. The CAN transceiver circuit 41 converts the logic levels of the microcontroller 10 into differential levels on the CAN bus 46, thereby establishing communication between the microcontroller 10 and the three module motors. The microcontroller 10 communicates with the nine-axis inertial measurement unit 39 via the I2C protocol to collect three-axis acceleration, three-axis angular acceleration, and three-axis magnetic field strength data, and then performs three-axis attitude angle calculation. The three-axis attitude angle calculation can be performed locally on the main controller 10 or transmitted to the host computer via the Ethernet bus. The attitude angle data can be used to realize the robot's motion control and environmental adaptation. The main controller 10 is equipped with a three-port Ethernet switch 38. The Ethernet MAC controller inside the microcontroller 40 is connected to the PHY layer of one port of the three-port Ethernet switch 38 via the RMII interface, while the other two ports of the switch are connected to two adjacent modules respectively. The Ethernet topology of the entire robot is daisy-chained. The 38 three-port Ethernet switch is preferably a switch chip that supports 100 Mbps full-duplex communication, automatic media-dependent interface cross-connection function, and RMII interface.

[0074] In Example 1, a variable-skin snake-like robot is provided, consisting of a head module 1, eight joint modules 2, a tail module 3, and a power signal bus 4 connected in series. In this example, the robot has 24 degrees of freedom and a total length of approximately 1760 mm. The connection method of adjacent joint modules 2 is as follows... Figure 7 As shown, the spatial angle between the axes of the third and first radial degrees of freedom of the adjacent joint is 90°.

[0075] When the robot performs a "passive skin" gait, the second axial degree of freedom of each joint module 2 is locked, and the spatial angle between the rotation axes of the first and third radial degrees of freedom within the module is maintained at 90°. At this time, the radial degrees of freedom within the entire robot are orthogonal to each other, that is, the rotation axes of two adjacent radial degrees of freedom are perpendicular to each other. In "passive skin" mode, the robot can perform biomimetic gaits such as meandering, rolling, and lateral sliding to adapt to rugged terrain.

[0076] When the robot performs an "active skin" gait, the second axial degrees of freedom within adjacent joint modules 2 coordinate their movements while maintaining their radial degrees of freedom at zero. At this time, the two adjacent axial degrees of freedom together form a cylindrical rotational structure, giving this part of the robot body wheel-like rotational characteristics. Furthermore, since the robot is composed of eight joint modules 2 connected in series, adjacent modules can be paired to form a set of cylindrical structures, thus constituting four sets of wheeled units. With the coordinated drive of these four sets of wheeled units, the robot can achieve continuous rolling motion similar to a wheeled robot, improving its movement efficiency and speed on flat terrain. The radial degrees of freedom between adjacent wheeled units are used to control the overall configuration of the robot, determining its direction of movement.

[0077] In Example 2, the above-described robot system is applied to loose terrain environments such as sandy areas. In this example, the robot adopts an "active skin" gait and a helical drive housing 47 is installed on each set of wheeled units (basic rotational units), i.e. Figure 10 and Figure 11 As shown, the helical drive housings 47 mounted on adjacent wheeled units have different helical directions, exhibiting an alternating "left-handed—right-handed—left-handed" distribution. This arrangement allows the propulsive forces generated by each helical drive housing 47 during movement to cancel each other out in the lateral direction, while forming a resultant force in the longitudinal direction. This resultant force stably points in the robot's forward direction, improving overall propulsion efficiency and motion stability. Figure 12 As shown, the top of the spiral section 51 of the spiral drive shell 47 adopts a rounded corner design. This design can increase the contact area between the shell and the ground surface, thereby improving the friction and motion adaptability on smooth ground. It can also enhance the propulsion ability of the shell in loose terrain such as sand while maintaining a certain depth, so as to achieve efficient movement in various terrain environments.

[0078] In Example 3, the above-described robot system is applied to an underwater environment. In this example, the robot adopts an "active skin" gait, and an underwater propulsion shell 52 is installed on a set of wheeled units closest to the robot's tail. The installation method and front view of the underwater propulsion shell 52 are shown below. Figure 13 and Figure 14As shown. In this embodiment, the wheeled unit equipped with the underwater propulsion shell 52 rotates to generate propulsion for the robot's forward movement; while the remaining joint degrees of freedom are used to control the robot's posture and direction of movement. Furthermore, the underwater propulsion shell 52 can also be installed on other wheeled units to obtain greater underwater propulsion.

[0079] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A three-degree-of-freedom joint module, characterized in that, It includes a front connecting plate, a front compartment, a rear compartment, and a rear connecting plate connected in sequence; the front compartment is equipped with a first motor with its output shaft in the vertical direction and a second motor with its output shaft in the horizontal direction; the rear compartment is equipped with a third motor with its output shaft in the vertical direction; the output shafts of the three motors correspond to form a first rotation axis, a second rotation axis, and a third rotation axis; The first motor drives the front connecting plate to rotate relative to the front compartment around the first rotation axis, forming a first radial degree of freedom, with a rotation angle range of -90° to +90°. The second motor drives the front compartment to rotate relative to the rear compartment around the second rotation axis, forming a second axial degree of freedom, and achieves infinite continuous rotation through a conductive slip ring; The third motor drives the rear connecting plate to rotate relative to the rear compartment around the third rotation axis, forming a third radial degree of freedom, with a rotation angle range of -90° to +90°.

2. A three-degree-of-freedom joint module according to claim 1, characterized in that, By adjusting the joint angle of the second axial degree of freedom, the spatial angle between the first rotation axis and the third rotation axis is changed, with an adjustment range of 0° to 180°.

3. A snake-like robot, characterized in that, It includes a head module, a joint module, a tail module, and a power signal bus connected in sequence; The head module collects environmental information; The joint module is a three-degree-of-freedom joint module as described in any one of claims 1-2; a plurality of the joint modules are connected in series between the head module and the tail module; The power signal bus runs through all modules and achieves electrical interconnection. Its end is led out from the tail module and is used for power supply and communication.

4. A snake-like robot according to claim 3, characterized in that, The adjacent joint modules are connected by a connector assembly; by adjusting the mechanical connection angle of the connector assembly, the angle between the third rotation axis of the preceding joint module and the first rotation axis of the following joint module is 0° or 90°.

5. A snake-like robot according to claim 4, characterized in that, The front connecting plate is provided with a front cover plate, and four notches are evenly distributed on the outer periphery of the front cover plate; the rear connecting plate is provided with a rear cover plate, and four insertion ends that match the notches are evenly distributed on the outer periphery of the rear cover plate. When adjacent joint modules are connected, the rear connecting plate of the previous module is inserted into the front connecting plate of the next module, and the connection and fixation are achieved through the cooperation of the plug end, notch and screw. The insertion end and the notch are symmetrically arranged at 90° intervals along the circumference, and the docking is completed under two relative orientations: the third rotation axis of the preceding module is parallel or perpendicular to the first rotation axis of the following module. The plug end, notch, and bolt constitute the connector assembly.

6. A snake-like robot according to claim 4, characterized in that, The second axial degree of freedom of each joint module is locked; adjacent joint modules are connected by the connector assembly, and the third radial degree of freedom axis of the preceding joint module is at a 90° angle to the first radial degree of freedom axis of the following joint module. At this time, the rotation axes of all radial degrees of freedom in the robot are orthogonal to each other in space.

7. A snake-like robot according to claim 4, characterized in that, Each pair of adjacent joint modules constitutes a basic rotation unit; in each basic rotation unit, the radial degree of freedom of the joint modules is locked at zero, and the rotation axes of the second axial degree of freedom of two adjacent joint modules in the unit are arranged in a coaxial direction; multiple basic rotation units are connected in series to form the main structure of the robot.

8. A snake-like robot according to claim 7, characterized in that, It also includes a helical drive housing for enabling land propulsion; The helical drive housing is fixed between two adjacent joint modules; By setting the second motor speed of the previous joint module to n and the second motor speed of the next joint module to -n, the helical drive housing is made to rotate at a constant speed.

9. A snake-like robot according to claim 8, characterized in that, The spiral directions of the spiral drive housings mounted on adjacent basic rotating units are different from each other, and they are distributed in an alternating pattern of left-handed, right-handed, and left-handed spirals.

10. A snake-like robot according to claim 7, characterized in that, It also includes an underwater propulsion hull for underwater propulsion; the underwater propulsion hull is installed between two adjacent joint modules; by setting the second motor speed of the first joint module to n and the second motor speed of the second joint module to -n, the underwater propulsion hull rotates at a constant speed.

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