A snake-like robot

Abstract

The present invention provides a snake-like robot, comprising a plurality of joints, wherein a steering mechanism is provided between each two adjacent groups of joints, the steering mechanism comprising a ball and pin seat assembly, wherein a group of ball and pin rods are hinged at each axial end of the ball and pin seat assembly, and each group of ball and pin rods is connected to a group of joints on the same side; each of the two adjacent groups of joints is provided with two groups of connecting rods facing the ball and pin seat assembly, and each group of connecting rods is connected to a driving mechanism for driving the connecting rods to telescopically move; four groups of end heads are radially arranged on the side wall of the ball and pin seat assembly, and the four groups of end heads are movably connected to the four groups of the ball and pin rods in a one-to-one correspondence, and among the four groups of end heads, two adjacent groups of end heads are respectively connected to the two groups of connecting rods in the same group of joints; in the snake-like robot of the present invention, each joint can realize pitch and yaw motions, and the power mechanism adopts an industrial lead screw mechanism, which has a stable, high-speed and strong propulsion effect, thereby realizing the effect of three-dimensional motion even in a complex environment.

Description

Technical Field

[0001] The invention relates to the field of bionic robots, in particular to a snake-like robot. Background Art

[0002] Snake robots are inspired by biological snakes, which have good maneuverability and can move on various complex types of terrain. The shape and movement of snake robots are designed after biological snakes. They have a high degree of freedom and flexible and diverse movement forms, and can play their unique advantages in specific occasions, such as detection and search and rescue work in occasions that are not suitable for manual operations. In addition, in the military, snake robots have the characteristics of compact structure, easy camouflage, and high stealth. They can complete reconnaissance and patrol tasks through the image transmission equipment they carry and the function of map construction. In the future, snake robots can even carry ammunition to complete tasks such as attack and blasting. The size of snake robots can vary over a large range. Large-sized snake robots carry tools at the end for industrial production, and micro-sized snake robots can be used in the medical industry to perform surgery.

[0003] In recent years, some universities such as Beijing Institute of Technology and Zhejiang University of Technology have designed snake-like robots with joints based on parallel connection, orthogonal connection or universal joint connection. In order to achieve the movement complexity and flexibility of bionic snakes, a cross-type universal joint connection method is adopted on the basis of the spherical universal joint mechanism. This design structure is relatively simple and easy to control, and the joint modules have good spatial flexibility; however, most of the existing snake-like robots use parallel connection and orthogonal connection, and these connection methods have their own defects. For example, the rotation secondary axes between each module of the parallel-connected snake-like robot are parallel to each other, so it can only perform two-dimensional movement; for example, the Chinese patent application with application number 202010853162.5 discloses a snake-like crawling robot, in which adjacent joints of the snake's body are connected by a steering mechanism, and the rotation The steering mechanism includes a cross steering joint and a screw pair that drives the cross steering joint to turn, making the movement of the snake body relatively flexible; however, it adopts an orthogonal connection. In any two adjacent groups of joints, the first and second ends of the cross steering joint are connected to the tail of the previous group of joints, and the third and fourth ends of the cross steering joint are connected to the head of the next joint. A set of screw pairs is arranged on the previous group of joints to drive the cross steering joint to swing around the axis from the third end to the fourth end in the horizontal plane, and the screw pairs on the next group of joints drive the cross steering joint to swing around the axis from the first end to the second end in the vertical plane. It has only two degrees of freedom, and the steering range between the two adjacent groups of joints is limited to swinging in the horizontal and vertical planes, which restricts the range of motion and the richness of the movements of the joints. Summary of the invention

[0004] The object of the present invention is to overcome the disadvantages of the background technology and provide a snake-like robot.

[0005] The embodiments of the present invention are implemented by the following technical solutions:

[0006] A snake-like robot comprises a plurality of joints, wherein a steering mechanism is provided between each two adjacent sets of joints, wherein the steering mechanism comprises a ball pin seat assembly, wherein a set of ball pin rods are hingedly connected at both axial ends of the ball pin seat assembly, and each set of ball pin rods is connected to a set of joints on the same side;

[0007] The two adjacent sets of joints are each provided with two sets of connecting rods facing the ball and pin seat assembly, and each set of connecting rods is connected to a driving mechanism for driving the connecting rods to telescopically move;

[0008] The side wall of the ball and pin seat assembly is also radially arranged with four groups of end heads, which are movably connected to the four groups of ball and pin rods in a one-to-one correspondence, and among the four groups of end heads, two adjacent groups of end heads are respectively connected to the two groups of connecting rods in the same group of joints.

[0009] Furthermore, the driving mechanism includes a screw pair arranged in the joint, wherein the screw of the screw pair is arranged parallel to the axial direction of the joint, and the slider of the screw pair is connected to the connecting rod, so that the movement of the slider on the screw drives the telescopic movement of the connecting rod.

[0010] Furthermore, the first end of the connecting rod is hinged to the end head, and the second end of the connecting rod is hinged to the sliding block.

[0011] Furthermore, on a projection plane perpendicular to the axial direction of the ball and pin seat assembly, the angles between any two adjacent groups of end heads in the four groups of end heads are 90°.

[0012] Further, among the four groups of end heads, any two adjacent groups of end heads are a group of end head assemblies, and the remaining two adjacent groups of end heads are a second group of end head assemblies, and the two groups of end head assemblies are respectively arranged on both sides of the midpoint of the ball pin seat assembly in the axial direction;

[0013] The two groups of ends in the end head assembly located on one side of the midpoint are connected to the two groups of connecting rods in the joint on the same side in a one-to-one correspondence.

[0014] Furthermore, each group of joints is provided with a plurality of rollers.

[0015] Furthermore, the joint is cylindrical, and at least two groups of rings are rotatably mounted on the outer wall of the joint; the at least two groups of rings are arranged along the axial direction of the joint, and a blocking mechanism is provided on the joint to prevent each group of rings from moving along the axial direction of the joint; and a plurality of the rollers are rotatably mounted on the outer ring surface of each group of rings.

[0016] Furthermore, a plurality of rotating parts are arranged around the inner wall of the circular ring, and the rotation axis of each group of rotating parts is parallel to the axis of the circular ring.

[0017] Further, the joint comprises a tube, and the driving mechanism is arranged in the tube;

[0018] Two groups of first limiting rings are protruding from the outer wall of the tube, and a group of retaining rings are threadedly connected to each end of the tube, and a second limiting ring is protruding from each group of retaining rings; the circular ring is sleeved on the outer wall of the tube between the first limiting ring and the second limiting ring on the same side; the blocking mechanism includes the first limiting ring and the second limiting ring.

[0019] Furthermore, a plurality of fixing components are evenly spaced on the outer edge of the circular ring, a group of the rollers is arranged between two adjacent groups of fixing components, and both ends of the rollers are rotatably connected to a group of fixing components respectively.

[0020] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0021] In the snake-like robot of the present invention, each joint can realize pitch and yaw motion, and the propeller adopts industrial screw propulsion, which has a stable, high-speed and strong propulsion effect, thereby realizing the effect of three-dimensional motion even in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the snake-like robot of the present invention;

[0023] Figure 2 for Figure 1 A magnified view of part A;

[0024] Figure 3 It is a schematic diagram of the steering mechanism structure of the snake-like robot of the present invention;

[0025] Figure 4 Schematic diagram of the joint structure of the snake-like robot of the present invention Figure 1 ;

[0026] Figure 5 Schematic diagram of the joint structure of the snake-like robot of the present invention Figure 2 ;

[0027] Figure 6 This is a schematic diagram of the joint structure of the snake-like robot of the present invention after the tube is removed;

[0028] Figure 7 It is a schematic structural diagram of the roller assembly of the snake-like robot of the present invention;

[0029] Figure 8The motion control principle diagram of the snake-like robot of the present invention;

[0030] Icons: 1-joint, 10-tube, 100-slider, 101-connecting rod, 102-guide rod, 103-motor, 104-screw, 105-first limiting ring, 106-connecting seat, 11-retaining ring, 110-second limiting ring, 2-steering mechanism, 20-ball pin seat assembly, 200-end, 21-ball pin rod, 3-roller assembly, 30-ring, 300-rotating part, 31-fixed assembly, 310-roller, 4-snake head. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Reference Figures 1 to 7 A snake-like robot comprises a plurality of joints 1, a steering mechanism 2 is arranged between each two adjacent sets of joints 1, the plurality of joints 1 are connected in series through the steering assembly 2, and a snake head 4 is connected to the joint at the front end.

[0034] The steering mechanism 2 includes a ball and pin seat assembly 20. Specifically, the ball and pin seat assembly 20 includes two groups of ball and pin seats. The bottoms of the two groups of ball and pin seats are connected and fixed together by screws. A group of ball and pin rods 21 are hinged at each axial end of the ball and pin seat assembly 20. Each group of ball and pin rods 21 is connected to a group of joints 1 on the same side. Specifically, a connecting seat 106 is provided in the center of both end portions of each group of joints 1, and the ends of the ball and pin rods 21 are connected to the connecting seats 106.

[0035] Reference Figure 4, each of the two adjacent groups of joints 1 is provided with two groups of connecting rods 101 facing the ball and pin seat assembly 20, and each group of connecting rods 101 is connected to a driving mechanism for driving the connecting rods 101 to telescopically move, and the driving mechanism includes a screw pair arranged in the joint 1, wherein the screw rod 104 of the screw pair is arranged parallel to the axial direction of the joint 1, and each group of screw rods 104 is connected to a group of motors 103, and the motor 103 is arranged in the joint 1. The slider 100 in the screw pair is connected to the connecting rod 101, and the movement of the slider 100 on the screw rod 104 drives the telescopic movement of the connecting rod 101. In addition, a guide rod 102 is also arranged in the joint 1 parallel to the length direction of the screw rod 104, and the slider 100 is inserted into the guide rod 102, so that the forward and backward sliding of the slider 100 is smoother.

[0036] Reference Figure 2 and Figure 3 Four groups of end heads 200 are radially arranged on the side wall of the ball and pin seat assembly 20, and the four groups of end heads 200 are movably connected to the four groups of ball and pin rods 21 in a one-to-one correspondence. Among the four groups of end heads 200, two adjacent groups of end heads 200 are respectively connected to the two groups of connecting rods 101 in the same group of joints 1, and the remaining two adjacent groups of end heads 200 are respectively connected to the two groups of connecting rods 101 in another group of joints 1.

[0037] In some preferred embodiments, the first end of each group of connecting rods 101 is hinged to the end head 200 , and the second end of each group of connecting rods 101 is hinged to the slider 100 .

[0038] It should be noted that, based on the above structure, in order to connect the several joints 1 in series, two groups of connecting rods 101 are provided at both ends of each group of joints 1, and each group of connecting rods 101 is connected to a group of driving mechanisms. Therefore, each group of joints 1 has four groups of screw pairs and four groups of motors 103.

[0039] In some preferred embodiments, on a projection plane perpendicular to the axial direction of the ball pin seat assembly 20, the angles between any two adjacent groups of end heads 200 in the four groups of end heads 200 are 90°. Figure 3 Among the four groups of end heads 200, any two adjacent groups of end heads 200 are a group of end head assemblies, and the remaining two adjacent groups of end heads 200 are a second group of end head assemblies. The two groups of end head assemblies are respectively arranged on both sides of the midpoint of the ball pin seat assembly 20 in the axial direction;

[0040] Reference Figure 2The two groups of end heads 200 in the end head assembly on the first side of the midpoint in the axial direction of the ball and pin seat assembly 20 are connected one-to-one with the two groups of connecting rods 101 in the joint 1 on the first side, and the two groups of end heads 200 in the end head assembly on the second side of the midpoint in the axial direction of the ball and pin seat assembly 20 are connected one-to-one with the two groups of connecting rods 101 in the joint 1 on the second side.

[0041] In addition, a plurality of rollers 310 are disposed on each group of joints 1 .

[0042] Specifically, the joint 1 is cylindrical, and at least two groups of rings 30 are rotatably mounted on the outer wall of the joint 1. The two groups of rings 30 are arranged along the axial direction of the joint 1, that is, the number of rings 30 can be set according to actual needs. In this embodiment, there are two groups. A blocking mechanism is provided on the joint 1 to prevent each group of rings 30 from moving along the axial direction of the joint 1. A plurality of rollers 310 are rotatably arranged on the outer ring surface of each group of rings 30. The ring 30 can rotate around the joint 1 as the axis. A plurality of rollers 310 are arranged on the ring 30 to make the movement of the pipe joint 1 more flexible.

[0043] Specifically, refer to Figure 6 A plurality of fixing components 31 are evenly spaced on the outer edge of the circular ring 30, a group of rollers 310 is arranged between two adjacent groups of fixing components 31, and both ends of the rollers 310 are rotatably connected to a group of fixing components 31 respectively. This design not only reduces the moving resistance of the snake-like robot and improves its motion resistance, but the flat surface between the two rollers 310 also increases the supporting area of ​​the snake body, thereby ensuring that the snake-like robot can dock and move stably.

[0044] In some preferred embodiments, in order to further improve the flexibility of the ring 30 and reduce the friction between the ring 30 and the outer wall of the joint 1, a plurality of rotating parts 300 are arranged around the inner wall of the ring 30, and the rotation axis of each group of rotating parts 300 is parallel to the axis of the ring 30.

[0045] In some preferred embodiments, the joint 1 includes a tube 10, and the driving mechanism is arranged in the tube 10. It should be noted that: in the present invention, the driving mechanism includes but is not limited to a gear rack driving mechanism, a linear module and any one of the aforementioned screw pairs.

[0046] Two groups of first limiting rings 105 are protrudingly provided on the outer wall of the tube 10, and a group of retaining rings 11 are threadedly connected to each end of the tube 10, specifically, the retaining rings 11 are threadedly engaged with the outer wall of the end of the tube 10 through the internal threads; a second limiting ring 110 is protrudingly provided on each group of retaining rings 11; the circular ring 30 is sleeved on the outer wall of the tube 10 between the first limiting ring 105 and the second limiting ring 110 on the same side; the blocking mechanism includes the first limiting ring 105 and the second limiting ring 110, and this structure allows the joint 1 to be easily disassembled and assembled.

[0047] In addition, the snake-like robot provided by the present invention is a snake-like intelligent bionic robot based on machine vision, reinforcement learning and snake-like curves. The main contents are divided into two parts. The first part is the snake-like physical mechanical structure with simple design, high efficiency and strong pressure resistance as described above; the second part is a control program with good robustness designed in combination with machine vision and reinforcement learning.

[0048] Through more intelligent control ideas and more optimized mechanical structures, the control ideas combine the advantages of reinforcement learning optimal control, precise target detection of machine vision and intelligent navigation of path planning, so that it can move smoothly and stably along the best route in complex environments. The innovation of mechanical structure is reflected in the design of the steering mechanism 2. Each joint 1 can realize pitch and yaw motion, and the power mechanism adopts industrial screw propulsion, which has stable, high-speed and strong propulsion effect.

[0049] Reference Figure 8 In terms of the control of the snake-like robot, the snake head 4 and each group of tube segments 1 are equipped with a controller and a sensor. For example, the controller can be a Raspberry Pi, that is, each group of joints 1 is provided with the aforementioned control module (hereinafter collectively referred to as the module), and each group of joints 1 is equipped with a built-in gyroscope to detect the snake-like posture, return the action parameters, and stabilize the forward action.

[0050] The serpentine motion control curve is highly fitted with the sine wave function, and the compiled Python program is applied to the Raspberry Pi. The Raspberry Pi of the snake head 4 and the tube segment 1 converts the motion into a PWM signal, and then controls the motor 103 through the motor drive module, thereby controlling the robot to complete the motion effect in space.

[0051] Specifically, in this embodiment, the snake robot is composed of 8 modules, each module contains a motor drive module and four motors 103, which are pitch and yaw motor groups. The first module is the host in the snake head 4, and the modules in the other joints 1 are slaves. The master and slave communicate through Web_Socket. The head of the snake head 4 is equipped with a camera, and the camera transmits images to the host for YOLO-V5 target detection to obtain environmental information. Then the host obtains the state and action based on the collected information through the DDPG algorithm of reinforcement learning, and then obtains the entire action sequence of an optimal path. Then the host sends the corresponding action of each module to the slave through Web_Socket communication according to the time sequence. Finally, the Raspberry Pi of each module converts the action into a PWM signal, so that the motor drive module in the module controls the two motor groups at both ends of each joint 1, achieving the effect of action in three-dimensional space.

[0052] The Raspberry Pi sends out a PWM signal, and the motor drive module controls the two motor groups. The moving parts output by the two motor groups are transmitted through the slider 100, and then drive the connecting rod 101, thereby pushing the steering mechanism 2, and then realizing the rotation of the joint.

[0053] The static friction during the rotation of the snake body generates an axial force, and its component force realizes the snake body's serpentine forward movement. The rollers are fixed in front and behind the joints through roller sleeves to reduce the forward friction.

[0054] Reference Figure 8 Specifically, each module contains a motor drive module and four motors 103, which are pitch and yaw motor groups respectively. The motor drive module in the module controls the two motor groups to achieve the effect of action in three-dimensional space. When not powered on, the slider 100 is in a balanced position and the steering mechanism 2 does not deviate. When a single motor 103 is connected to a forward or reverse voltage, the motor 103 pushes the slider 100 connected thereto to move forward or reversely, and the slider 100 drives the connecting rod 101 to extend or retreat, thereby pulling the steering mechanism 2 to rotate in one-dimensional direction. Adjacent joints 1 are connected through the steering mechanism 2, which can achieve maximum snake body deflection.

[0055] The snake-like robot obtains the power to move forward by rubbing against the ground through the swinging of its body. The roller 310, as a motion-assisting mechanism, can generate a large normal friction force to prevent slipping, while gradually reducing the resistance to motion and improving the motion efficiency of the snake-like robot. The design of the roller 310 enables the robot to have a larger ground contact area, so that the robot has a more stable three-dimensional motion capability.

[0056] The electrical system of the serpentine bionic robot involved in the present invention comprises a DC regulated power supply, a 78M05 step-down module, an L298 reduction motor control module, a reduction motor and other components. Since the robot uses a large number of electronic devices, the present invention optimizes the design of the control circuit.

[0057] The specific model of the Raspberry Pi controller of the robot is rasberry_zero_wh, which is used to control the swing of joint 1 and snake head 4 at the same time. By adjusting the duty cycle and delay time of the PWM wave output by the Raspberry Pi, the different running time and speed of the motor 103 can be controlled. Then, by coordinating the speed and action sequence of each motor 103, the robot can complete the specified action, thereby realizing the movement similar to the crawling of a snake. The crawling action of a snake is a rhythmic movement similar to the sine wave fluctuation. When moving on land, the friction between the point where the snake robot contacts the ground and the ground pushes the robot to move. By controlling the speed and running time of the motor 103, the robot can be controlled to move forward or turn.

[0058] Sensors are installed at the snake head 4, and gyroscopes are installed at the snake body 1. Combined with reinforcement learning, various parameters during movement are returned. During the test, it was found that the robot's various levels are highly coordinated, the movement is stable and high-speed, and the gyroscope makes it less affected by the environment and has a fast response.

[0059] The snake-like robot of the present invention is a special bionic robot made according to the movement principle of snakes, which has the following advantages in complex environments:

[0060] (1) During the exercise, the body always stays close to the ground, and the low center of gravity walking method makes the movement stable;

[0061] (2) It relies on the swing of the body to obtain forward momentum through friction, giving it a certain ability to automatically avoid obstacles;

[0062] (3) Its slender body and various gaits enable it to pass through narrow spaces and some gullies, and it has the ability to climb rod-shaped objects. It plays a role in exploration and operation in dangerous and complex environments, and has important application prospects.

[0063] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A snake-like robot, comprising a plurality of joints (1), wherein a steering mechanism (2) is provided between each two adjacent sets of joints (1), wherein: The steering mechanism (2) comprises a ball pin seat assembly (20), wherein a group of ball pin rods (21) are hingedly connected at both axial ends of the ball pin seat assembly (20), and each group of ball pin rods (21) is connected to a group of joints (1) on the same side; The two adjacent groups of joints (1) are each provided with two groups of connecting rods (101) facing the ball and pin seat assembly (20), and each group of connecting rods (101) is connected to a driving mechanism for driving the connecting rods (101) to telescopically move; Four groups of end heads (200) are radially arranged on the side wall of the ball pin seat assembly (20), and the four groups of end heads (200) are movably connected to the four groups of ball pin rods (21) in a one-to-one correspondence, and among the four groups of end heads (200), two adjacent groups of end heads (200) are respectively connected to two groups of connecting rods (101) in the same group of joints (1); The driving mechanism comprises a screw pair arranged in the joint (1), wherein the screw rod (104) of the screw pair is arranged parallel to the axial direction of the joint (1), and the slider (100) of the screw pair is connected to the connecting rod (101), so that the movement of the slider (100) on the screw rod (104) drives the telescopic movement of the connecting rod (101); On a projection plane perpendicular to the axial direction of the ball and pin seat assembly (20), the angles between any two adjacent groups of end heads (200) in the four groups of end heads (200) are all 90°.

2. The snake-like robot according to claim 1, characterized in that: The first end of the connecting rod (101) is hinged to the end head (200), and the second end of the connecting rod (101) is hinged to the sliding block (100).

3. The snake-like robot according to claim 1, characterized in that: Among the four groups of end heads (200), any two adjacent groups of end heads (200) are a group of end head assemblies, and the remaining two adjacent groups of end heads (200) are a second group of end head assemblies, and the two groups of end head assemblies are respectively arranged on both sides of the midpoint of the ball pin seat assembly (20) in the axial direction; The two groups of ends (200) in the end assembly located on one side of the midpoint are connected to the two groups of connecting rods (101) in the joint (1) on the same side in a one-to-one correspondence.

4. The snake-like robot according to any one of claims 1 to 3, characterized in that: A plurality of rollers (310) are arranged on each group of joints (1).

5. The snake-like robot according to claim 4, characterized in that: The joint (1) is cylindrical, and at least two groups of circular rings (30) are rotatably mounted on the outer wall of the joint (1); the at least two groups of circular rings (30) are arranged along the axial direction of the joint (1), and a blocking mechanism is provided on the joint (1) for preventing each group of circular rings (30) from moving along the axial direction of the joint (1); and a plurality of rollers (310) are rotatably mounted on the outer ring surface of each group of circular rings (30).

6. The snake-like robot according to claim 5, characterized in that: A plurality of rotating parts (300) are also arranged around the inner wall of the circular ring (30), and the rotation axis of each group of rotating parts (300) is parallel to the axis of the circular ring (30).

7. The snake-like robot according to claim 5 or 6, characterized in that: The joint (1) comprises a tube (10), and the driving mechanism is arranged in the tube (10); Two groups of first limiting rings (105) are protrudingly provided on the outer wall of the tube (10), and a group of retaining rings (11) are respectively threadedly connected at both ends of the tube (10), and a second limiting ring (110) is protrudingly provided on each group of retaining rings (11); the circular ring (30) is sleeved on the outer wall of the tube (10) between the first limiting ring (105) and the second limiting ring (110) on the same side; the blocking mechanism includes the first limiting ring (105) and the second limiting ring (110).

8. The snake-like robot according to claim 5, characterized in that: A plurality of fixed components (31) are evenly spaced on the outer edge of the circular ring (30), a group of rollers (310) is arranged between two adjacent groups of fixed components (31), and two ends of the rollers (310) are respectively rotatably connected to a group of fixed components (31).

Images