An amphibious serpentine robot

Abstract

The application relates to an amphibious snake-shaped robot, belonging to the technical field of mechanical arms. The amphibious snake-shaped robot comprises at least two propulsion mechanisms, at least one omnidirectional joint and at least one waterproof cover. The waterproof cover is sleeved outside the omnidirectional joint. A plurality of steel rings are embedded on the inner side of the waterproof cover. The omnidirectional joint comprises a first rotating mechanism, a second rotating mechanism and a third rotating mechanism for rotationally connecting the two. The first rotating mechanism is connected with one propulsion mechanism and drives the propulsion mechanism to rotate around a first axis L1. The second rotating mechanism is connected with another propulsion mechanism and drives the propulsion mechanism to rotate around a second axis L2. When the first rotating mechanism and the second rotating mechanism rotate together, the steel rings are squeezed, the steel rings push the third rotating mechanism, the size of the included angle between the first axis L1 and the second axis L2 is adjusted, and the squeezing force borne by the steel rings is released. The amphibious snake-shaped robot provided by the application can avoid that the squeezing force acting on the steel rings is too large when the joint moves.

Description

Technical Field

[0001] This application relates to the field of robotic arm technology, and more specifically, to an amphibious snake robot. Background Technology

[0002] Amphibious serpentine robots have attracted widespread attention due to their unique advantages in complex environments such as disaster ruins, narrow pipes, and shallow swamps. The core motion unit of this type of robot is its omnidirectional joint, which needs to have multi-degree-of-freedom rotation capabilities to achieve flexible serpentine movement, while also having a robust waterproof structure to ensure the reliability of its underwater functions.

[0003] In existing technologies, a common solution to the waterproofing problem of omnidirectional joints is to cover the mechanical joint with a flexible waterproof cover. However, this waterproofing solution has an inherent drawback: to enhance the deformation resistance and structural integrity of the waterproof cover, designers typically embed reinforcing metal rings (such as steel rings) at intervals inside the flexible waterproof cover. While this improvement enhances the morphological stability of the waterproof cover to some extent, it introduces more challenging technical problems:

[0004] When a robot's omnidirectional joints undergo complex movements, especially when multiple rotational mechanisms (such as those rotating around the yaw and pitch axes) need to operate simultaneously, the waterproof cover is compressed and stretched from the inside. In this situation, the internally embedded rigid steel rings not only cannot flexibly adapt to this complex deformation, but also become the object of compression and jamming due to their own rigidity. This compression significantly increases the resistance to joint rotation, and in severe cases, can even completely hinder the intended movement of the joint, leading to inaccurate robot movements, stiff actions, and a significant consumption of drive energy.

[0005] Under continuous, uneven compression, the steel ring undergoes irreversible plastic deformation. Once deformed, the ring no longer maintains its circular shape, and its twisted portion generates localized stress and continuous scratching against the inner wall of the waterproof cover. This hard wear caused by structural deformation rapidly undermines the integrity of the waterproof cover material, leading to its rupture and loss of sealing function. Internal drive components are subsequently damaged by water immersion, causing the entire joint unit to fail.

[0006] Therefore, there is an urgent need in this field for an innovative omnidirectional joint design that can avoid excessive compressive forces acting on the steel ring during joint movement, prevent harmful plastic deformation of the steel ring, and thus fundamentally solve the problems of motion interference and sealing failure. Summary of the Invention

[0007] The purpose of this application is to address the above-mentioned problems by providing an amphibious snake robot that can avoid excessive compressive force acting on the steel ring during joint movement, thereby improving the aforementioned problems.

[0008] This application is achieved through the following technical solution:

[0009] This application provides an amphibious serpentine robot, which includes at least two propulsion mechanisms, at least one omnidirectional joint, and at least one waterproof cover. The omnidirectional joint is disposed between and connected to two adjacent propulsion mechanisms. The waterproof cover is fitted over the outside of the omnidirectional joint. Multiple steel rings are spaced apart and embedded on the inner side of the waterproof cover along its length. The omnidirectional joint includes a first rotation mechanism, a second rotation mechanism, and a third rotation mechanism rotatably connecting the two. The first rotation mechanism is connected to one propulsion mechanism, and the second rotation mechanism is connected to the other propulsion mechanism. The first rotation mechanism drives the corresponding propulsion mechanism to rotate around a first axis L1, and the second rotation mechanism drives the corresponding propulsion mechanism to rotate around a second axis L2. When the first and second rotation mechanisms rotate together, they compress the steel rings inside the waterproof cover, causing the steel rings to push the third rotation mechanism, thereby adjusting the angle between the first axis L1 and the second axis L2 projected onto the same plane to release the compressive force on the steel rings.

[0010] In the technical solution of this application embodiment, the amphibious serpentine robot adjusts the angle between the projections of the first axis L1 and the second axis L2 onto the same plane through a third rotation mechanism. This allows the omnidirectional joints to release the compressive force on the steel ring in a timely manner during complex rotations, reducing rotational resistance and preventing joint jamming or inaccurate movement. The robot's movement is more flexible and smooth, suitable for scenarios such as meandering. Reduced rotational resistance means lower drive energy consumption, allowing the robot to operate more efficiently and for longer periods. The steel ring no longer undergoes plastic deformation due to compression, thus avoiding scratching and localized stress on the inner wall of the waterproof cover. The integrity of the waterproof cover is maintained, ensuring reliable sealing performance and effectively preventing water from entering the internal drive components, extending the robot's service life.

[0011] In some embodiments, the first rotating mechanism and the second rotating mechanism have the same structure. The first rotating mechanism includes a first driving member and a first transmission frame. The first driving member is connected to a corresponding propulsion mechanism. The first transmission frame is connected to the third rotating mechanism. The first driving member is used to drive the first transmission frame to rotate.

[0012] In the technical solution of this application embodiment, the first rotating mechanism and the second rotating mechanism have the same structure, meaning that their parts can be interchanged. This not only simplifies the manufacturing and assembly process but also reduces maintenance costs and spare parts inventory costs. Because the first rotating mechanism and the second rotating mechanism have the same structure, their motion inertia and response characteristics are highly consistent. This allows the propulsion mechanisms on both sides to move more synchronously and in coordination when the snake robot performs complex meandering movements, reducing energy loss caused by internal motion conflicts and resulting in a smoother and more predictable motion posture.

[0013] In some embodiments, the third rotating mechanism includes a rotating shaft and two rotating parts, which are rotatably sleeved on the rotating shaft and arranged along the length of the rotating shaft; the two rotating parts are respectively connected to the first transmission frame of the first rotating mechanism and the second rotating mechanism.

[0014] In the technical solution of this application embodiment, the third rotation mechanism is designed as a purely passive mechanism. It utilizes the internal force (steel ring compression force) generated by the motion itself as a feedback signal and power source to automatically adjust the included angle to release stress. This eliminates the inherent contradiction between the rigid steel ring and joint movement, ensuring smooth motion. The passive adjustment of the third rotation mechanism is a real-time, dynamic, and continuous process. No matter how complex the snake robot's motion is, the waterproof cover and steel ring can always find a force balance point through this mechanism, keeping the sealing system in optimal working condition and achieving adaptive and long-term protection for the core drive components.

[0015] In some embodiments, the number of omnidirectional joints is n, where n≥1; the number of propulsion mechanisms is n+1; wherein the omnidirectional joints and propulsion mechanisms are arranged alternately.

[0016] In the technical solution of this application embodiment, the robot's body is decomposed into multiple segments connected by joints. The number of omnidirectional joints, n, directly determines the number of bending points that the robot's body can achieve. The larger n is, the more bending points there are, the more flexible the robot's body is, and the more complex the continuous spatial curves it can present are. This achieves a qualitative leap from simple polygonal motion to continuous wave-like motion, enhancing its ability to pass through narrow and twisted environments.

[0017] In some embodiments, the propulsion mechanism includes a pair of impellers with blades rotating in opposite directions; the pair of impellers are coaxially arranged and capable of rotating in opposite directions.

[0018] In the technical solution of this application embodiment, the opposing rotation of a pair of impellers with blades rotating in opposite directions causes their generated counter-torques (i.e., the torque that causes the robot to spin) to cancel each other out due to their opposite directions. This allows all the power output by the propulsion mechanism to be converted into pure axial thrust, unlike a single impeller, which generates thrust along with a torque that could cause the robot to overturn uncontrollably. This provides a stable linear propulsion basis for the serpentine robot. With a pair of coaxial, counter-rotating impellers, the latter impeller can recover some of the rotational kinetic energy from the wake of the former impeller and convert it into additional thrust, thereby improving the energy utilization efficiency of the entire propulsion system to a certain extent. Simultaneously, canceling out the counter-torques also means that the robot body will not experience unnecessary roll or yaw vibrations, providing a more stable working platform for the mounted equipment.

[0019] In some embodiments, the propulsion mechanism further includes a second drive member, a pair of second transmission frames, and a first gear set. The second drive member is connected to an omnidirectional joint; the pair of second transmission frames are respectively connected to a pair of impellers; the second drive member is directly connected to one of the second transmission frames and connected to the other second transmission frame through the first gear set, thereby driving the pair of impellers to rotate in opposite directions.

[0020] In the technical solution of this application embodiment, the propulsion mechanism achieves the synchronous counter-rotation of a pair of impellers using only one second driving component. Compared with the traditional solution of using two independent motors to drive the two impellers separately, this saves space inside the propulsion mechanism, making the structure very compact. It also reduces the complexity of electrical control and the overall weight and power consumption, which is crucial for underwater robots where space and energy are extremely precious. Since the rotation of the two impellers originates from the same second driving component and is rigidly connected by mechanical gears, they have an inherent and mandatory synchronous relationship. This means that under any operating condition, the rotational speeds of the two impellers remain absolutely consistent, thus ensuring perfect cancellation of counter-torque and providing extremely stable pure axial thrust. Gear transmission is an efficient and reliable power transmission method. The first gear set (e.g., using planetary gears or a simple idler gear structure) distributes power to the two impellers without slippage, resulting in a short transmission path and low energy loss, thereby improving the overall transmission efficiency from the second driving component to the thrust.

[0021] In some embodiments, the surface of the blade facing away from the rotation axis of the impeller is an arc surface.

[0022] In the technical solution of this application embodiment, the curved surface structure enables the blades to operate like hydrofoils, generating thrust based on the lift principle. Compared to the flat blades that mainly rely on drag to propel water, this significantly improves propulsion efficiency, thrust, and anti-cavitation capability at high speeds. The curved shape also gives the impeller better maneuverability on complex terrain. It reduces sinking resistance on soft ground and allows for smoother traversal of rocky or vegetated terrain, achieving a seamless transition from water to shore. On land, flat blades easily scoop up soil, making robot movement difficult and causing a surge in energy consumption. Curved blades, with their smooth contours, can guide soil and obstacles to slide sideways and upwards, reducing drag. This means that under the same terrain, the robot requires less torque to move, or in other words, it completes the same distance with lower energy consumption, extending the endurance of land missions. The curved surface design avoids rigid collisions and jamming between the edges of the flat blades and ground obstacles. When encountering insurmountable obstacles, the impeller is more likely to slide or climb rather than get stuck. This reduces the impact load on the transmission system, reduces the risk of failure, and improves the reliability of the amphibious snake robot in unknown land environments.

[0023] In some embodiments, in a pair of impellers, one impeller has a plurality of rotatable rollers on the side of its blades facing away from the axis of rotation; the axis of rotation of the rollers is perpendicular to the length direction of the blades.

[0024] In the technical solution of this application embodiment, by setting rollers on the blades of one of the impellers, the land mobility performance is optimized in a targeted manner without significantly affecting underwater propulsion, thereby achieving a balance in the robot's performance in two media.

[0025] In some embodiments, the rollers protrude from the surface of the blade away from the axis of rotation; multiple rollers are arranged along the arc surface of the blade.

[0026] In the technical solution of this application embodiment, by ensuring that the rollers protrude from the blade surface, the possibility of sliding friction between the blade body and the ground is eliminated. Almost all the resistance to the robot's land movement comes from the rolling friction of the rollers themselves, further reducing energy consumption and noise. The arrangement of multiple rollers along the curved surface of the blade means that the distribution of the roller support points matches the force-bearing structure of the blade. This layout provides uniform and stable support force upon contact with the ground, preventing the blade from deforming due to single-point force.

[0027] In some embodiments, in two adjacent propulsion mechanisms, the blades of the impellers equipped with rollers rotate in opposite directions.

[0028] In the technical solution of this application embodiment, if the blades of all impellers equipped with rollers rotate in the same direction, they will generate a superimposed lateral torque when they touch the ground, causing the robot as a whole to tend to deflect to one side, resulting in deviation. This application solves this problem by making the roller impellers of adjacent mechanisms rotate in opposite directions, so that the deflection torque generated by one propulsion mechanism is canceled out by the reverse torque generated by the adjacent propulsion mechanism. This ensures the inherent stability of the snake robot when moving in a straight line on land, eliminating the need for continuous direction correction by the control system, thus reducing energy consumption and control complexity. In addition, when the torque cannot be completely canceled out and residual torsional stress is formed in the universal joint between the two (such as when the rollers on the two propulsion mechanisms have different grounding conditions), the passive adjustment mechanism of the third rotation mechanism can immediately release it, ensuring that the system is always in a dynamic mechanical equilibrium state, rather than a rigid confrontation, thereby improving the smoothness and energy efficiency of land movement. This process of releasing torsional stress transforms harmful static torque into harmless short-term dynamic adjustment, protecting the core transmission and internal structural units of the snake robot, and improving the overall lifespan and reliability of the machine.

[0029] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a structural schematic diagram of an amphibious serpentine robot provided in some embodiments of this application;

[0032] Figure 2 Schematic diagrams of the omnidirectional joint and waterproof cover provided for some embodiments of this application;

[0033] Figure 3 This is a schematic diagram of the structure of the omnidirectional joint of the first rotating mechanism when it rotates, provided in some embodiments of this application;

[0034] Figure 4 A schematic diagram of the structure of an omnidirectional joint when the first rotating mechanism and the second rotating mechanism rotate simultaneously, as provided in some embodiments of this application;

[0035] Figure 5 A schematic diagram of the structure of an omnidirectional joint when the first rotating mechanism, the second rotating mechanism, and the third rotating mechanism rotate simultaneously, as provided in some embodiments of this application;

[0036] Figure 6 This is a schematic diagram of the overall structure of an amphibious serpentine robot provided in some embodiments of this application;

[0037] Figure 7 for Figure 6 Enlarged view of point A in the middle;

[0038] Figure 8 A partial cross-sectional view of a propulsion mechanism provided for some embodiments of this application;

[0039] Figure 9 A partial cross-sectional view of a propulsion mechanism provided for other embodiments of this application.

[0040] Icons: 1-Propulsion mechanism; 10-Impeller; 100-Blade; 1000-Roller; 11-Second driving component; 12-Second transmission frame; 13-First gear set; 2-Omnidirectional joint; 20-First rotating mechanism; 200-First driving component; 201-First transmission frame; 21-Second rotating mechanism; 22-Third rotating mechanism; 220-Shaft; 221-Rotating part; 3-Waterproof cover; 30-Steel ring. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0043] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] In this application, "multiple" means two or more (including two).

[0046] According to some embodiments of this application, optionally, such as Figures 1-5As shown, this application provides an amphibious serpentine robot, which includes at least two propulsion mechanisms 1, at least one omnidirectional joint 2, and at least one waterproof cover 3. The omnidirectional joint 2 is disposed between two adjacent propulsion mechanisms 1 and connected to them. The waterproof cover 3 is fitted on the outside of the omnidirectional joint 2. The waterproof cover 3 has multiple steel rings 30 embedded at intervals along its length direction on its inner side. The omnidirectional joint 2 includes a first rotation mechanism 20, a second rotation mechanism 21, and a third rotation mechanism 22 rotatably connecting the two. The first rotation mechanism 20 is connected to one propulsion mechanism 1, and the second rotation mechanism 21 is connected to the other propulsion mechanism 1. The first rotation mechanism 20 is used to drive the corresponding propulsion mechanism 1 to rotate around a first axis L1, and the second rotation mechanism 21 is used to drive the corresponding propulsion mechanism 1 to rotate around a second axis L2. When the first rotation mechanism 20 and the second rotation mechanism 21 rotate together, they compress the steel rings 30 inside the waterproof cover 3, causing the steel rings 30 to push the third rotation mechanism 22, thereby adjusting the size of the angle between the first axis L1 and the second axis L2 projected on the same plane, so as to release the compressive force on the steel rings 30.

[0047] The waterproof cover 3 mentioned in this application has a corrugated pipe structure, and the steel ring 30 is embedded in the inner side of the outward protrusion of the waterproof cover 3.

[0048] The waterproof cover 3 corresponds one-to-one with the omnidirectional joint 2.

[0049] The amphibious serpentine robot is designed to perform exploration or transport tasks in complex environments such as underwater mines, disaster ruins, or shallow swamps. The robot includes at least two propulsion mechanisms 1 (e.g., propellers or wheeled drive units), and an omnidirectional joint 2 positioned between the two propulsion mechanisms 1, sealed and protected by a waterproof cover 3. Multiple steel rings 30 are spaced along the inner side of the waterproof cover 3 along its length to enhance structural stability.

[0050] The omnidirectional joint 2 includes a first rotation mechanism 20, a second rotation mechanism 21, and a third rotation mechanism 22 rotatably connecting the two. The first rotation mechanism 20 is connected to a propulsion mechanism 1, and the second rotation mechanism 21 is connected to another propulsion mechanism 1. In actual motion, the first rotation mechanism 20 drives the corresponding propulsion mechanism 1 to rotate around a first axis L1 (e.g., yaw motion), and the second rotation mechanism 21 drives the corresponding propulsion mechanism 1 to rotate around a second axis L2 (e.g., pitch motion). When the robot needs to turn in a narrow pipe or adapt to uneven terrain, the first rotation mechanism 20 and the second rotation mechanism 21 will act simultaneously, performing compound rotation.

[0051] During this process, the steel ring 30 inside the waterproof cover 3 is compressed due to the deformation caused by the simultaneous movement of the first rotating mechanism 20 and the second rotating mechanism 21. However, in the universal joint provided in this application, the combined rotation of the first rotating mechanism 20 and the second rotating mechanism 21 compresses the steel ring 30, causing the steel ring 30 to push the third rotating mechanism 22. The third rotating mechanism 22 then responds by adjusting the angle between the first axis L1 and the second axis L2 projected onto the same plane (e.g., a horizontal reference plane). For example, when the projected angle between L1 and L2 is adjusted from an acute angle to an obtuse angle, the compressive force on the steel ring 30 is released, thereby preventing the steel ring 30 from being continuously compressed or twisted. This adjustment is dynamic and occurs in real time as the amphibious snake robot moves, ensuring that the steel ring 30 is always in a low-stress state.

[0052] The amphibious serpentine robot provided in this application utilizes a third rotating mechanism 22 to adjust the angle between the projections of the first axis L1 and the second axis L2 onto the same plane. This allows the omnidirectional joint 2 to promptly release the compressive force on the steel ring 30 during complex rotations, reducing rotational resistance and preventing joint jamming or inaccurate movement. The robot's movement is more flexible and fluid, suitable for scenarios such as meandering. Reduced rotational resistance means lower drive energy consumption, allowing the robot to operate more efficiently and for longer periods. The steel ring 30 no longer undergoes plastic deformation due to compression, thus avoiding scratching and localized stress on the inner wall of the waterproof cover 3. The integrity of the waterproof cover 3 is maintained, ensuring reliable sealing performance and effectively preventing water from entering the internal drive components, extending the robot's service life.

[0053] According to some embodiments of this application, optionally, such as Figures 2-5 As shown, the first rotating mechanism 20 has the same structure as the second rotating mechanism 21. The first rotating mechanism 20 includes a first driving member 200 and a first transmission frame 201. The first driving member 200 is connected to the corresponding propulsion mechanism 1. The first transmission frame 201 is connected to the third rotating mechanism 22. The first driving member 200 is used to drive the first transmission frame 201 to rotate.

[0054] When an amphibious robot moves in its working environment, the front end in the direction of forward movement is the head of the amphibious robot, and the rear end in the direction of forward movement is the tail of the amphibious robot.

[0055] The head and tail of an amphibious serpentine robot can be equipped with robotic arms, detection sensors, and other operational devices to enable the robot to perform corresponding functions. For example, the head of the amphibious serpentine robot can be equipped with a robotic arm, and the tail can be equipped with detection sensors. The robotic arm at the head can fix itself in complex underwater environments, while the detection sensors at the tail can move around in the operational environment to collect the necessary data.

[0056] The first rotation mechanism 20 and the second rotation mechanism 21 of the omnidirectional joint 2 of the amphibious serpentine robot provided in this application have identical structures. This means that the units that drive the two propulsion mechanisms 1 to perform yaw or pitch movements have the same mechanical structure.

[0057] Taking the first rotating mechanism 20 as an example, it includes a first driving component 200 (such as a servo motor) and a first transmission frame 201. The first driving component 200 is directly or indirectly connected to a propulsion mechanism 1 (such as through a gear set) and is responsible for providing power; the first transmission frame 201 is rotatably connected to the third rotating mechanism 22 and is used to transmit motion.

[0058] When the robot needs to raise its head (pitch motion) and simultaneously turn (yaw motion) in the working environment, the first drive member 200 drives the first transmission frame 201 to rotate around the first axis L1. At the same time, the first drive member 200 in the second rotating mechanism 21, which has the same structure, drives the first transmission frame 201 to rotate around the second axis L2. The combined action of these two rotating mechanisms, as described previously, will generate a compound compression and stretching effect on the waterproof cover 3 and its internal steel ring 30 from the inside.

[0059] At this moment, the symmetrical and synchronous rotational motion transmits the force to the third rotation mechanism 22 through the steel ring 30. The third rotation mechanism 22 then generates adaptive motion, adjusting the angle between the first axis L1 and the second axis L2 projected onto the same plane (e.g., the ground on which the robot travels). This adjustment process essentially transforms the dead force that originally acted on the steel ring 30, causing it to undergo plastic deformation, into an activity that drives the joint to make minute pose adjustments, thereby instantly releasing the compressive force borne by the steel ring 30.

[0060] The first rotating mechanism 20 and the second rotating mechanism 21 have identical structures, meaning their parts are interchangeable. This not only simplifies the manufacturing and assembly process but also reduces maintenance and spare parts inventory costs. Because the first rotating mechanism 20 and the second rotating mechanism 21 have identical structures, their motion inertia and response characteristics are highly consistent. This allows the propulsion mechanisms 1 on both sides to move more synchronously and coordinately during complex meandering movements of the serpentine robot, reducing energy loss caused by internal motion conflicts and resulting in smoother and more predictable motion.

[0061] According to some embodiments of this application, optionally, such as Figures 3-5 As shown, the third rotating mechanism 22 includes a rotating shaft 220 and two rotating parts 221. The two rotating parts 221 are rotatably sleeved on the rotating shaft 220 and arranged along the length direction of the rotating shaft 220. The two rotating parts 221 are respectively connected to the first transmission frame 201 of the first rotating mechanism 20 and the second rotating mechanism 21.

[0062] The rotating part 221 mentioned in this application may be a bearing housing, a bushing, or any component containing rolling bearings / sliding bearings, and its core function is to achieve low-resistance independent rotation on the rotating shaft 220.

[0063] The core of the third rotating mechanism 22 includes a rotating shaft 220 and two independently rotatable rotating parts 221. These two rotating parts 221 are rotatably mounted on the rotating shaft 220 and arranged along the length of the rotating shaft 220 to form a core structure similar to a cross shaft or universal joint.

[0064] During the movement, the first driving components 200 of the first rotating mechanism 20 and the second rotating mechanism 21 actively drive the corresponding first transmission frame 201 to rotate around the first axis L1 and the second axis L2, respectively. These two active rotations combine to compress the flexible waterproof cover 3 from the inside, forcing the steel ring 30 embedded in the waterproof cover 3 to bear pressure. The pressure-bearing steel ring 30 uses this compressive force as a traction force, directly acting on the third rotating mechanism 22, pushing it to produce adaptive movement. Under this thrust, the rotating shaft 220 and the rotating part 221 of the third rotating mechanism 22 are forced to change their relative positions. This change manifests as an additional relative rotation between the first transmission frame 201 and the second transmission frame 12. It is this passively generated rotation that adjusts in real time the angle between the first axis L1 and the second axis L2 projected onto the same plane. Once the angle between the first axis L1 and the second axis L2 projected onto the same plane is adjusted to a new equilibrium position, the excessive compressive force originally acting on the steel ring 30 is successfully released, and the steel ring 30 returns to a low-stress state, thereby avoiding plastic deformation and motion jamming.

[0065] This application designs the third rotating mechanism 22 as a purely passive mechanism, utilizing the internal force generated by the motion itself (the compressive force of the steel ring 30) as a feedback signal and power source to automatically complete the angle adjustment to release stress. This eliminates the inherent contradiction between the rigid steel ring 30 and the joint movement, ensuring smooth motion. The passive adjustment of the third rotating mechanism 22 is a real-time, dynamic, and continuous process. No matter how complex the snake robot's motion is, the waterproof cover 3 and the steel ring 30 can always find the force balance point through this mechanism, keeping the sealing system in optimal working condition and achieving adaptive and long-term protection for the core drive components.

[0066] In the specific implementation process, a miniature torque or angle sensor can be embedded inside the rotating shaft 220 to directly monitor the relative motion state and force between the two rotating parts 221, so as to determine the position of the head (or tail) of the snake robot and to judge the overall force state of the snake robot.

[0067] According to some embodiments of this application, optionally, such as Figure 1 and Figure 6 As shown, the number of omnidirectional joints 2 is n, n≥1; the number of propulsion mechanisms 1 is n+1; wherein, the omnidirectional joints 2 and propulsion mechanisms 1 are arranged alternately.

[0068] The staggered arrangement of the omnidirectional joints 2 and the propulsion mechanism 1 ensures the spacing between the power unit (propulsion mechanism 1) and the motion guidance unit (omnidirectional joints 2). The rotation of each omnidirectional joint 2 can directly and effectively change the posture of its two adjacent body segments, thereby efficiently transmitting local motion and synthesizing it into an overall wave motion.

[0069] The larger the value of n, the longer the body of the amphibious snake robot becomes, with more joints and propulsion units, enabling it to achieve highly realistic snake-like meandering movements and traverse extremely complex spaces.

[0070] Regardless of the value of n, the staggered arrangement rule ensures that each omnidirectional joint 2 is directly connected to two propulsion mechanisms 1, and each propulsion mechanism 1 (except those located at the beginning and end) is also connected to two omnidirectional joints 2.

[0071] The amphibious serpentine robot architecture provided in this application decomposes the robot's body into multiple segments connected by joints. The number of omnidirectional joints 2, n, directly determines the number of bending points that the robot's body can achieve. The larger n is, the more bending points there are, the more flexible the robot's body is, and the more complex the continuous spatial curves it can present are. This achieves a qualitative leap from simple zigzag motion to continuous wave-like motion, enhancing its ability to pass through narrow and twisted environments.

[0072] According to some embodiments of this application, optionally, such as Figures 6-7 As shown, the propulsion mechanism 1 includes a pair of impellers 10 with opposite directions of rotation of blades 100; the pair of impellers 10 are coaxially arranged and can rotate in opposite directions.

[0073] When the robot needs to generate thrust to move forward or backward in the water, the power system drives the pair of impellers 10 to rotate simultaneously around the same axis at the same speed but in opposite directions. Since the blades 100 rotate in opposite directions, the axial thrust generated by the two impellers 10 is in the same direction, and when combined, they form a powerful net thrust that drives the robot to move along its body axis.

[0074] In propulsion mechanism 1, the opposing rotations of a pair of blades 100 and impellers 10 cancel each other out due to their opposite directions, resulting in counter-torques (i.e., the torque that causes the robot to spin). This ensures that all the power output by propulsion mechanism 1 is converted into pure axial thrust, unlike a single impeller 10 which generates thrust along with a torque that could cause the robot to flip uncontrollably. This provides a stable linear propulsion basis for the serpentine robot. The pair of coaxial, counter-rotating impellers 10 allow the latter impeller 10 to recover some of the rotational kinetic energy from the wake of the former impeller 10 and convert it into additional thrust, thereby improving the energy efficiency of the entire propulsion system to some extent. Simultaneously, canceling out the counter-torques means that the robot body will not experience unnecessary roll or yaw vibrations, providing a more stable working platform for the mounted equipment.

[0075] The cancellation of the anti-torque also reduces the vibration source of the propulsion system. Combined with the smoothing effect of the coaxial counter-rotating impeller 10 on the vortex, it helps to reduce underwater operating noise, which is of great significance in ecological monitoring applications.

[0076] According to some embodiments of this application, optionally, such as Figures 8-9 As shown, the propulsion mechanism 1 also includes a second drive member 11, a pair of second transmission frames 12 and a first gear set 13. The second drive member 11 is connected to the omnidirectional joint 2. The pair of second transmission frames 12 are respectively connected to a pair of impellers 10. The second drive member 11 is directly connected to one of the second transmission frames 12 and connected to the other second transmission frame 12 through the first gear set 13, thereby driving the pair of impellers 10 to rotate in opposite directions.

[0077] In practical applications, the housing of the second drive unit 11 (typically a waterproof motor) is fixedly connected to the omnidirectional joint 2 for support. The output shaft of the second drive unit 11 is directly connected to one of the second transmission frames 12, thereby directly driving the rotation of an impeller 10 connected to that transmission frame. Simultaneously, the output power of the second drive unit 11 is transmitted to the other second transmission frame 12 through the first gear set 13. The core function of the first gear set 13 is to change the direction of rotation while transmitting power. Through this series of arrangements, the unidirectional rotation of a single second drive unit 11 is synchronously converted into the opposite rotational motion of the two second transmission frames 12 at the same speed, ultimately driving a pair of impellers 10 to achieve precise reverse rotation.

[0078] The propulsion mechanism provided in this application achieves the synchronous counter-rotation of a pair of impellers 10 using only one second drive element 11. Compared with the traditional scheme of using two independent motors to drive the two impellers 10 separately, this saves space inside the propulsion mechanism 1, making the structure very compact. At the same time, it also reduces the complexity of electrical control and the overall weight and power consumption, which is crucial for underwater robots where space and energy are extremely precious. Since the rotation of the two impellers 10 originates from the same second drive element 11 and is rigidly connected by mechanical gears, they have an inherent and forced synchronous relationship. This means that under any operating condition, the rotational speed of the two impellers 10 remains absolutely consistent, thereby ensuring perfect cancellation of anti-torque and providing extremely stable pure axial thrust. Gear transmission is an efficient and reliable power transmission method. The first gear set 13 (e.g., using planetary gears or a simple idler gear structure) distributes power to the two impellers 10 without slippage, with a short transmission path and low energy loss, thereby improving the overall transmission efficiency from the second drive element 11 to the thrust.

[0079] According to some embodiments of this application, optionally, such as Figures 7-9 As shown, the surface of the blade 100 that is away from the rotation axis of the impeller 10 is an arc surface.

[0080] When the amphibious serpentine robot moves in water, the impeller 10 rotates at high speed. Water flows over the curved surface of the blade 100. According to the principles of fluid dynamics, the curved surface (similar to an airfoil) can efficiently generate lift and convert this lift into a powerful axial thrust, propelling the robot forward.

[0081] When moving on the ground, the impeller 10 functions as a wheel or track replacement that interacts with the ground. When the robot travels on soft or uneven ground (such as swamps, sand, or grass), the curved edge of the blade 100 contacts the ground before the flat blade 100. This curved design reduces the contact area, thereby reducing drag on soft ground; the smooth curved surface of the blade 100 can more smoothly roll over or push aside small obstacles (such as pebbles or shrubs), rather than being prone to getting stuck or digging holes like the flat blade 100; when greater grip is needed, specific parts of the curved surface can cut deeper into the soft ground through the robot's movement, providing a certain amount of traction.

[0082] The curved surface structure allows the blade 100 to operate like a hydrofoil, generating thrust based on the principle of lift. Compared to the flat blade 100, which mainly relies on drag to propel water, this significantly improves propulsion efficiency, thrust, and anti-cavitation capabilities at high speeds. The curved shape also gives the impeller 10 better maneuverability on complex terrain. It reduces sinking resistance on soft ground and allows for smoother traversal of rocky or vegetated terrain, achieving a seamless transition from water to shore. On land, the flat blade 100 easily scoops up soil, causing difficulties for robot movement and a surge in energy consumption. The curved blade 100, with its smooth contour, guides soil and obstacles to slide laterally and upward, reducing drag. This means that on the same terrain, the robot requires less torque to move, or in other words, it completes the same distance with lower energy consumption, extending the endurance for land missions. The curved surface design avoids rigid collisions and jamming between the edge of the flat blade 100 and ground obstacles. When encountering an insurmountable obstacle, the impeller 10 is more likely to slide or climb rather than get stuck. This reduces the impact load on the transmission system, reduces the risk of failure, and improves the reliability of the amphibious snake robot in unknown land environments.

[0083] In practice, special hydrophobic / mud-repellent textures or coatings can be designed on the curved surface to make it difficult for aquatic plants, silt and other attachments to remain or to be automatically thrown off during movement, thus maintaining the working efficiency of the impeller 10 in various environments.

[0084] According to some embodiments of this application, optionally, such as Figures 6-9 As shown, in a pair of impellers 10, one of the impellers 10 has multiple rotatable rollers 1000 on the side of the blade 100 away from the axis of rotation; the axis of rotation of the rollers 1000 is perpendicular to the length direction of the blade 100.

[0085] When the blade 100, equipped with rollers 1000, touches the ground, the rollers 1000 on it will make initial contact with the ground. Since the rollers 1000 can rotate freely, their interaction with the ground changes from sliding friction to rolling friction. This reduces the frictional force that the impeller 10 needs to overcome when moving on land, making the serpentine robot move more effortlessly and smoothly, and significantly reducing noise. When the robot is in water, these small rollers 1000 have negligible impact on the water flow due to their size and rotatability. They are propelled by the water flow and rotate freely, generating almost no additional resistance.

[0086] Components designed for optimized underwater performance (such as large-area curved blades 100) often perform poorly on land (high drag and rapid wear). This application addresses this by installing rollers 1000 on the blades 100 of one of the impellers 10, thereby specifically optimizing land mobility without significantly affecting efficient underwater propulsion, achieving a balance in robot performance between the two media.

[0087] According to some embodiments of this application, optionally, such as Figures 6-9 As shown, the roller 1000 protrudes from the surface of the blade 100 away from the axis of rotation; multiple rollers 1000 are arranged along the arc surface of the blade 100.

[0088] When the impeller 10 rotates and the blade 100 contacts the ground, the protruding roller 1000 is the only part in contact with the ground. The curved surface of the blade 100 itself is lifted off the ground, avoiding any form of scratching and wear. The rollers 1000 are arranged along the curved surface so that at any stage of the impeller 10's rotation, as long as the blade 100 enters the contact range, the rollers 1000 are in the most suitable contact position, providing continuous and smooth rolling support.

[0089] This application eliminates the possibility of sliding friction between the blade 100 and the ground by ensuring that the roller 1000 protrudes from the surface of the blade 100. Almost all the resistance to the robot's land movement comes from the rolling friction of the roller 1000 itself, further reducing energy consumption and noise. The arrangement of multiple rollers 1000 along the arc surface of the blade 100 means that the distribution of the rollers' support points matches the force-bearing structure of the blade 100. This layout provides uniform and stable support force upon contact with the ground, preventing the blade 100 from deforming due to single-point force.

[0090] According to some embodiments of this application, optionally, such as Figure 6 As shown, in two adjacent propulsion mechanisms 1, the blades 100 of the impeller 10 with rollers 1000 rotate in opposite directions.

[0091] If all the blades 100 of the impellers 10 equipped with rollers 1000 rotate in the same direction, they will generate a superimposed lateral torque upon contact with the ground, causing the robot as a whole to tend to deflect to one side, resulting in deviation. This application addresses this by having the impellers 100 of adjacent mechanisms rotate in opposite directions, so that the deflection torque generated by one propulsion mechanism 1 is canceled out by the opposing torque generated by the adjacent propulsion mechanism 1. This ensures the inherent stability of the serpentine robot when moving in a straight line on land, eliminating the need for continuous direction correction by the control system, thus reducing energy consumption and control complexity. Furthermore, when the torques cannot be completely canceled out and residual torsional stress is formed in the universal joint between them (such as when the grounding conditions of the rollers 1000 on the two propulsion mechanisms 1 are different), the passive adjustment mechanism of the third rotation mechanism 22 can immediately release it, ensuring that the system is always in a dynamic mechanical equilibrium state rather than a rigid confrontation, thereby improving the smoothness and energy efficiency of land movement. This process of releasing torsional stress resolves harmful static torque into harmless short-term dynamic adjustment, protecting the core transmission and internal structural units of the snake robot and improving the overall lifespan and reliability of the machine.

[0092] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An amphibious snake robot, characterized in that, The amphibious snake-like robot comprises: at least two propulsion mechanisms; at least one omni-joint arranged between and connected to two adjacent propulsion mechanisms; at least one waterproof cover arranged outside the omni-joint; wherein a plurality of steel rings are arranged inside the waterproof cover along the length direction of the waterproof cover; the omni-joint comprises a first rotating mechanism, a second rotating mechanism, and a third rotating mechanism connected to the first rotating mechanism and the second rotating mechanism; the first rotating mechanism is connected to one of the propulsion mechanisms and is used to drive the corresponding propulsion mechanism to rotate around a first axis L1; the second rotating mechanism is connected to the other propulsion mechanism and is used to drive the corresponding propulsion mechanism to rotate around a second axis L2; when the first rotating mechanism and the second rotating mechanism rotate together, the steel rings inside the waterproof cover are squeezed, and the steel rings push the third rotating mechanism, so as to adjust the size of the included angle between the first axis L1 and the second axis L2 projected on the same plane, and release the squeezing force on the steel rings; the first rotating mechanism and the second rotating mechanism have the same structure, and the first rotating mechanism comprises: a first driving member connected to the corresponding propulsion mechanism; a first transmission frame connected to the third rotating mechanism; the first driving member is used to drive the first transmission frame to rotate; the third rotating mechanism comprises a rotating shaft and two rotating parts, and the two rotating parts are rotatably arranged on the rotating shaft and arranged along the length direction of the rotating shaft; the two rotating parts are respectively connected to the first transmission frames of the first rotating mechanism and the second rotating mechanism.

2. The amphibious snake-like robot according to claim 1, wherein: the number of omni-joints is n, and n≥1; the number of propulsion mechanisms is n+1; the omni-joints and the propulsion mechanisms are arranged alternately.

3. The amphibious snake-like robot according to claim 1, wherein: the propulsion mechanism comprises a pair of impellers with opposite rotating directions; the pair of impellers are coaxially arranged and can rotate in opposite directions.

4. The amphibious snake robot according to claim 3, wherein, the propulsion mechanism further comprises: a second driving member connected to the omni-joint; a pair of second transmission frames respectively connected to the pair of impellers; a first gear set; the second driving member is directly connected to one of the second transmission frames and connected to the other second transmission frame through the first gear set, so as to drive the pair of impellers to rotate in opposite directions.

5. The amphibious snake-like robot according to claim 3, wherein: the surface of the blade away from the rotating axis of the impeller is an arc surface.

6. The amphibious snake-like robot according to claim 5, wherein: one of the pair of impellers is provided with a plurality of rotatable rollers on the side of the blade away from the rotating axis; the rotating axis of the roller is perpendicular to the length direction of the blade.

7. The amphibious snake-like robot according to claim 6, wherein: the roller protrudes from the surface of the blade away from the rotating axis; a plurality of rollers are arranged along the arc surface of the blade.

8. The amphibious snake robot according to claim 6, wherein, The two adjacent propelling mechanisms are opposite in the rotation direction of the blades of the impeller with the rollers.

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