Earthworm-like biomimetic robot based on shape memory alloy and magnetic field

Abstract

This application discloses a worm-inspired robot based on shape memory alloy and magnetic field, belonging to the field of soft robot technology. It not only shortens the contraction cycle and improves work efficiency but also achieves free steering and expands its application range. The robot includes at least one main structure; the main structure includes a bellows, a telescopic column structure, two magnet plates, two fixing rings, and multiple helical shape memory alloy wires; each end of the bellows is connected to a magnet plate via a fixing ring, and the two magnet plates are arranged facing each other with the same poles; the middle of the helical shape memory alloy wires passes through the bellows, and both ends are connected to corresponding fixing rings, with multiple helical shape memory alloy wires evenly distributed along the circumference of the bellows; the helical shape memory alloy wires contract and return to their helical state when energized; the telescopic column structure is located inside the bellows, and its two ends can provide different levels of resistance to the robot, thereby assisting the robot in moving forward or turning.

Description

Technical Field

[0001] This application relates to the field of soft robot technology, and in particular to a biomimetic earthworm robot based on shape memory alloy and magnetic field. Background Technology

[0002] Existing biomimetic earthworm robots are powered by two types of sources. One type uses a traditional structure, employing servo motors to mimic the muscle contractions of an earthworm. The disadvantages of this design include: complex structure, high failure rate, large weight and size, and high manufacturing cost. The other type uses pneumatic or smart materials as a power source. Its disadvantages include: limited control methods, difficulty in completing complex tasks, slow movement speed, and poor practical application results. For some robots, the use of electromagnets instead of bristles for body fixation restricts their application scenarios.

[0003] Furthermore, with the rapid development of soft robotics based on smart materials, soft robots based on shape memory alloy wires have emerged in large numbers due to their outstanding advantages such as simple structure, high force-to-weight ratio, low cost, and simple supporting equipment. However, most soft robots based on shape memory alloy wires cannot achieve free movement and can only perform simple forward and backward movements. In addition, due to the unique heating deformation and heat dissipation recovery characteristics of shape memory alloy wires, the deformation of the wires requires a long heating and cooling cycle. Therefore, robots powered by shape memory alloy wires often have long single work cycles and poor motion capabilities, mostly reaching speeds of only millimeters per second. At the same time, due to the lack of in-depth research on the controllability and intelligence of these robots, it is difficult to achieve precise control of the robot's motion path. Moreover, the advantage of the high force-to-weight ratio of shape memory alloy wire-based robots has not been effectively utilized to incorporate more intelligent sensors. Therefore, how to achieve efficient and controllable multi-directional motion of intelligent soft robots remains a problem worthy of in-depth investigation. Summary of the Invention

[0004] The embodiments of this application provide a biomimetic earthworm robot based on shape memory alloy and magnetic field, which not only shortens the contraction cycle and improves work efficiency, but also achieves free turning and expands the scope of application.

[0005] To achieve the above objectives, embodiments of this application provide a biomimetic earthworm robot based on shape memory alloy and magnetic field, comprising at least one main structure; the main structure includes a corrugated tube, a telescopic column structure, two magnet plates, two fixing rings, and multiple helical shape memory alloy wires; each end of the corrugated tube is connected to a magnet plate via a fixing ring, and the two magnet plates are arranged facing each other with the same poles; the middle portion of each helical shape memory alloy wire passes through the corrugated tube, and both ends are connected to corresponding fixing rings, and the multiple helical shape memory alloy wires are evenly distributed along the circumference of the corrugated tube; the helical shape memory alloy wires contract and return to a helical state when energized; the telescopic column structure is located inside the corrugated tube, and the two ends of the telescopic column structure can provide different levels of resistance for the biomimetic earthworm robot based on shape memory alloy and magnetic field, thereby assisting the biomimetic earthworm robot based on shape memory alloy and magnetic field to move forward or turn.

[0006] Furthermore, a set of first telescopic rod telescopic channels are provided on the fixing ring; the telescopic column structure includes a rubber column and end caps slidably connected to both ends of the rubber column; a set of second telescopic rod telescopic channels are provided on the side wall of the end cap; the distances between the two sets of second telescopic rod telescopic channels and the outer end face of the end cap are not equal; a set of telescopic rods are respectively hinged to both ends of the rubber column; the telescopic rods extend out of the fixing ring after passing through the corresponding second telescopic rod telescopic channels and the first telescopic rod telescopic channels in sequence.

[0007] Furthermore, each group of the telescopic rods consists of eight rods, which are evenly distributed along the circumference of the rubber column.

[0008] Furthermore, the two sets of telescopic rods correspond one-to-one.

[0009] Furthermore, there are four spiral shape memory alloy wires.

[0010] Furthermore, the magnet plate is a neodymium magnet plate.

[0011] Furthermore, the sidewall of the fixing ring is provided with a slit for the spiral shape memory alloy wire to pass through.

[0012] Furthermore, the retaining ring is made of ABS material and is 3D printed.

[0013] Furthermore, there are multiple main structures, and the multiple main structures are magnetically connected.

[0014] This application has the following advantages over the prior art:

[0015] 1. The robot in this embodiment uses a helical shape memory alloy wire as its power source. The mutual repulsion of neodymium magnets provides the robot with additional restoring force, shortening its work cycle and improving its mobility. The unique telescopic column structure mimics the bristles of an earthworm to generate resistance differences during movement, ensuring reliable module movement and not limiting its use to special environments (such as ferromagnetic environments). Simultaneously, the current flowing through the shape memory alloy wire can be controlled to cause partial contraction, controlling the robot's shape and allowing it to actively adapt to complex pipe structures.

[0016] 2. The robot in this embodiment adopts a modular structure, which allows for the series connection of multiple identical units, providing redundancy to ensure that the robot as a whole can maintain normal movement even if one or more modules malfunction. Furthermore, a single module can carry different sensors, and connecting multiple modules in series enables the integration of various functions, making the robot more intelligent.

[0017] 3. In the embodiments of this application, the robot can be energized by only one or a few shape memory alloy wires to produce bending and contraction in a certain direction. Then, the movement resistance at both ends of the robot can be adjusted by the telescopic column structure, so that the robot can achieve free turning in any direction. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application;

[0020] Figure 2 This is an external view of Embodiment 1 of this application;

[0021] Figure 3 This is a schematic diagram of the structure of the fixing ring in Embodiment 1 of this application. Figure 1 ;

[0022] Figure 4 This is a schematic diagram of the structure of the fixing ring in Embodiment 1 of this application. Figure 2 ;

[0023] Figure 5 This is an external view of the telescopic column structure in Embodiment 1 of this application;

[0024] Figure 6 This is a schematic diagram illustrating the principle of contraction and movement in Embodiment 1 of this application;

[0025] Figure 7 This is a schematic diagram of the turning principle in Embodiment 1 of this application;

[0026] Figure 8 This is a schematic diagram of the structure of Embodiment 2 of this application;

[0027] Figure 9 This is the state during turning in Embodiment 2 of this application. Figure 1 ;

[0028] Figure 10 This is the state during turning in Embodiment 2 of this application. Figure 2 ;

[0029] Figure 11 This is a diagram showing the state during contraction in Embodiment 2 of this application. Detailed Implementation

[0030] 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, and 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.

[0031] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, as fixed connection, detachable connection, or integral connection; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0034] Example 1:

[0035] Reference Figure 1 and Figure 2 This application provides an earthworm-inspired robot based on shape memory alloy and magnetic field, comprising a main structure 10. The main structure 10 includes a corrugated pipe 1, a telescopic column structure 2, two magnet plates 3, two fixing rings 4, and four spiral shape memory alloy wires 5.

[0036] The corrugated pipe 1 is made of polyethylene and has an internal telescopic column structure 2, with a fixing ring 4 connected to each end. Specifically, the fixing ring 4 is embedded in a groove in the corrugated pipe 1 for secure connection. The fixing ring 4 is made of ABS material and is 3D printed. (Refer to...) Figure 3 and Figure 4 The shape of the fixing ring 4 is similar to that of a single section of the bellows 1. Its sidewall cross-section resembles a "V" shape, with the bottom dimension of the "V" equal to the maximum outer diameter of the bellows 1, and the opening dimension of the "V" equal to the diameter of the concave portion of the bellows 1. A magnet plate 3 is provided inside the fixing ring 4, with two magnet plates 3 arranged face-to-face with the same poles. Specifically, the magnet plate 3 is a neodymium magnet. Since the attraction force of neodymium magnets can reach up to 15 times that of the strongest existing ferrite magnets, it is more suitable for connection in soft robots compared to other magnets. Additionally, four baffles 41 for limiting the movement of the magnet plate 3 are provided on the end face of the fixing ring 4 away from the bellows 1. A set of first telescopic rod telescopic channels 42 is also formed on the inclined surface of the fixing ring 4 near the bellows 1. It should be noted that a portion of the first telescopic rod telescopic channels 42 can also be formed on the bellows 1.

[0037] Four spiral shape memory alloy wires 5 are evenly distributed along the circumference of the corrugated pipe 1, and the middle of each of the four spiral shape memory alloy wires 5 passes through the corrugated pipe 1. Each end of the spiral shape memory alloy wire is connected to a corresponding fixing ring 4 and extends out of the fixing ring 4. Specifically, the side wall of the fixing ring 4 is provided with a slit 43 for the fixing ring 4 to pass through. The spiral shape memory alloy wires 5 are stretched when the power is off and contracted to return to the spiral state when the power is on.

[0038] Reference Figure 5 The telescopic column structure 2 includes a rubber column 21 and end caps 22 slidably connected to both ends of the rubber column 21. The bellows 1 is made of polyethylene. A set of second telescopic rod telescopic channels 23 is opened on the side wall of the end cap 22. It should be noted that the distances between the two sets of second telescopic rod telescopic channels 23 and the outer end face of the end cap 22 are not equal. For example, refer to... Figure 1 and Figure 5 The distance between the left end cap 22 and its outer end face is less than the distance between the right end cap 22 and its outer end face.

[0039] A set of telescopic rods is hinged to each end of the rubber column 21, with two sets of telescopic rods corresponding one-to-one. Each set of telescopic rods includes eight telescopic rods 24 evenly distributed along the circumference of the rubber column 21. The telescopic rods 24 are made of nylon, and each telescopic rod 24 passes through the corresponding second telescopic rod telescopic channel 23 and first telescopic rod telescopic channel 42 before extending out of the fixing ring 4. The cross-section of the telescopic rod 24 is square, and both the first telescopic rod telescopic channel 42 and the second telescopic rod telescopic channel 23 are elongated holes. The telescopic column structure 2 allows one end of the telescopic rod 24 to extend while the other end retracts in the base state, and the extended and retracted ends are interchanged in the retracted state, thereby providing a suitable resistance difference, mimicking the bristle retraction of an earthworm robot. Thus, the two ends of the telescopic column structure 2 can provide different levels of resistance to the robot, thereby assisting the robot of this application in moving forward or turning.

[0040] The working principle of the earthworm-inspired bionic robot based on shape memory alloy and magnetic field in this application embodiment is as follows:

[0041] Reference Figure 6 In its initial state, the spiral shape memory alloy wire 5 is straightened by restoring force. When the robot of this embodiment needs to move forward, the spiral shape memory alloy wire 5 is energized. The energized wire generates heat and simultaneously contracts, causing deformation. Since the spiral alloy wire is embedded in the fixing rings 4 at both ends, its contraction causes the bellows 1 to deform accordingly, achieving contraction. When the power to the spiral shape memory alloy wire 5 is de-energized, it loses its contraction force and elongates. Simultaneously, the restoring force of the bellows 1 and the repulsive force of the magnet plate 3 work together to drive the robot back to its initial state. Thus, by controlling the frequency of energizing the spiral shape memory alloy wire 5 and repeating this process, the robot can obtain a controllable contraction frequency. Furthermore, due to the different outer diameters of the telescopic rod 24 at both ends of the telescopic rod 24 located inside the bellows 1 in the initial and contracted states, the forward resistance at both ends of the robot will differ, causing the robot to move in the direction of less resistance.

[0042] Reference Figure 7 Because different driving parameters (such as the frequency, voltage, current, and duty cycle of the PWM wave fed into the shape memory alloy wires) can control the contraction frequency and length of one or more helical shape memory alloy wires 5, as well as the magnetic field characteristics, this characteristic allows the robot in this embodiment to turn when needed. By energizing only one or a few helical shape memory alloy wires 5, bending and contracting in a specific direction, and then adjusting the resistance at both ends of the robot using the telescopic column structure 2, the robot can achieve turning and free displacement. Furthermore, since this embodiment uses resistance adjustment for forward movement, the motion environment does not need to be ferromagnetic, enhancing its environmental adaptability.

[0043] Example 2:

[0044] Reference Figure 8 This application also provides an earthworm-inspired bionic robot based on shape memory alloy and magnetic field, comprising three main structures 10 connected in series. It should be noted that the number of main structures 10 can also be two or four, the specific number determined according to actual working conditions, and is not limited here. Specifically, the three main structures 10 are magnetically connected, and the helical shape memory alloy wires 5 in adjacent main structures 10 are connected together. Thus, the magnet plates 3 at both ends of the main structure 10 can connect different modules, and the magnetic field directions of adjacent magnetic plates of adjacent modules are opposite, generating attraction, enabling rapid connection and replacement. Furthermore, a structure with more than one module can be considered a redundant design, which can enhance the robot's robustness, meaning that the robot's normal function will not be affected when some modules malfunction.

[0045] Reference Figures 9 to 11 , Figure 9 The diagram shows a state diagram of one main structure 10 bending while the other two main structures 10 are in a basic state in Embodiment 2. Figure 10 The diagram shows a state diagram of two main structures 10 bending and another main structure 10 in a basic state in Embodiment 2. Figure 11 The diagram shows the state of the robot in Embodiment 2 when the main structures 10 at both ends are contracted and the middle main structure 10 is in its basic state. It can be seen that by controlling the helical shape memory alloy wires 5 in the multiple main structures 10 of Embodiment 2, different degrees of contraction and extension recovery of the robot can be achieved, thereby realizing deflection and posture in different directions. Specifically, intermittent heating of the helical shape memory alloy wires 5 in different modules is beneficial for cooling the helical shape memory alloy wires. While the shape memory alloy wire in one module is cooling and extending, the helical shape memory alloy wires in other modules can still be heated and contracted to generate movement, preventing them from remaining stationary, thereby improving driving efficiency and increasing the crawling speed of the earthworm-like robot.

[0046] Since the basic structure of the main structure 10 in this application embodiment is the same, different length designs of the robot can be realized by combining modules. In addition, each module can be equipped with different sensors and has good load carrying capacity. Thus, they can be connected in series to form a multi-functional robot.

[0047] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A biomimetic earthworm robot based on shape memory alloy and magnetic field, characterized in that, The system includes at least one main structure; the main structure comprises a corrugated tube, a telescopic column structure, two magnet plates, two fixing rings, and multiple spiral shape memory alloy wires; each end of the corrugated tube is connected to a magnet plate via a fixing ring, and the two magnet plates are arranged facing each other with the same poles; the middle of each spiral shape memory alloy wire passes through the corrugated tube, and both ends are connected to corresponding fixing rings, and the multiple spiral shape memory alloy wires are evenly distributed along the circumference of the corrugated tube; the spiral shape memory alloy wires contract and return to a spiral state when energized; the telescopic column structure is located inside the corrugated tube, and the two ends of the telescopic column structure can provide different levels of resistance for the earthworm-like bionic robot based on shape memory alloy and magnetic field, thereby assisting the earthworm-like bionic robot based on shape memory alloy and magnetic field to move forward or turn; A set of first telescopic rod telescopic channels is provided on the fixed ring; the telescopic column structure includes a rubber column and end caps slidably connected to both ends of the rubber column; a set of second telescopic rod telescopic channels is provided on the side wall of the end cap; the distances between the two sets of second telescopic rod telescopic channels and the outer end face of the end cap are not equal; A set of telescopic rods is hinged to each end of the rubber column; the telescopic rods pass through the corresponding second telescopic rod telescopic channel and the first telescopic rod telescopic channel in sequence and then extend out of the fixing ring.

2. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 1, characterized in that, Each group consists of eight telescopic rods, which are evenly distributed along the circumference of the rubber column.

3. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 2, characterized in that, The two sets of telescopic rods correspond one-to-one.

4. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 2, characterized in that, There are four spiral shape memory alloy wires.

5. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 1, characterized in that, The magnet plate is a neodymium magnet plate.

6. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 1, characterized in that, The side wall of the fixing ring is provided with a slit for the spiral shape memory alloy wire to pass through.

7. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 1, characterized in that, The retaining ring is made of ABS material and is 3D printed.

8. The earthworm-inspired robot based on shape memory alloy and magnetic field according to claim 1, characterized in that, The main structure comprises multiple structures, which are magnetically connected.

Images