Rock Loach-like Soft Wall-Climbing Robot

Abstract

The present invention provides a soft wall-climbing robot that imitates a rock loach, wherein: the internal moving cylinder of the flexible spine subsystem is axially retractable relative to the external sleeve through the drive of a flexible driving module, and can be reset by a reset spring; the bending degree of the flexible belt on either side of the flexible driving module increases with the contraction of the shape memory alloy wire, and the force generated by the bending deformation serves as the driving force of the flexible spine subsystem; the bionic suction cup system drives multiple unfolding structures to stretch or bend as a whole through the stretching or contraction of the first shape memory alloy spring, realizing the switching of suction cup adsorption and desorption, and the bottom surface of the lip ring has a micro-nano structure for limiting the retreat of the lip ring. The present invention can realize the inverted adsorption of the robot on a smooth top surface, and the crawling movement at any azimuth on the vertical avoidance.

Description

Technical Field

[0001] The invention relates to a bionic wall-climbing robot, more specifically to a soft wall-climbing robot imitating a rock loach. Background Art

[0002] In recent years, stable crawling on smooth and flat wall scenes has become one of the research hotspots in the field of wall-climbing robots. At present, researchers from all over the world have developed a variety of soft structures and robots that can crawl on flat and smooth substrates. For example, China Patent CN110294041A discloses a soft climbing robot based on a flexible bristle structure, and China Patent CN110153996A discloses a soft robot bionic foot with high environmental adaptability, and the Tankbot developed by Unver et al. of Carnegie Mellon University based on dry adhesives. These robots have successfully achieved horizontal smooth wall movement, but have not yet achieved higher angle adhesion. In order to provide driving force, robots often require a large air pump, and even have to be equipped with bulky mechanical structures, which hinder the robot's end effector from overcoming gravity and dragging itself to move. Based on this situation, the Wenli team of Beijing University of Aeronautics and Astronautics designed a bionic crawling robot based on a soft suction cup, but the robot uses hydraulic drive, which makes it too large and complex to control. Summary of the invention

[0003] The present invention aims to solve the above technical problems, and for this purpose proposes a soft wall-climbing robot imitating a rock loach, so as to enable the robot to be invertedly adsorbed on a smooth top surface, and to crawl vertically at any azimuth angle.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A soft wall-climbing robot imitating a rock loach comprises a flexible spine system consisting of two groups of flexible spine subsystems arranged one in front of the other and rotatably connected via a rotating connector, and also comprises a flexible driving module and a bionic suction cup system configured for each group of flexible spine subsystems;

[0006] The flexible spine subsystem comprises an outer sleeve and an inner moving cylinder coaxially mounted and connected with a reset spring, the end of the outer sleeve facing the fixed connecting piece and connected, the end of the inner moving cylinder facing the rotating connecting piece and connected, and can be axially retracted relative to the outer sleeve by the drive of the flexible driving module, and can be reset by the reset spring;

[0007] The flexible driving module comprises a pair of flexible belts in an arc-shaped belt structure, which are respectively arranged on the left and right sides of the flexible spine subsystem. The pair of flexible belts face each other with inner concave surfaces and surround the flexible spine subsystem, and are respectively connected between the fixed connector and the rotating connector at both ends of the flexible spine subsystem. The flexible belts are embedded with heat-shrinkable shape memory alloy wires arranged along the entire length of the belt body. The flexible belts are bendable, and the bending degree of the flexible belts on either side increases with the shrinkage of the shape memory alloy wires. The force generated by the bending deformation serves as the driving force of the flexible spine subsystem.

[0008] The bionic suction cup system is arranged at the bottom of the outer sleeve, and includes a suction cup with an adsorption surface facing downward, a pair of symmetrically arranged lip rings extending on the left and right sides of the suction cup, a plurality of front-to-back spaced folding structures connected between the lip ring and the upper end of the suction cup, and a plurality of heat-shrinkable first shape memory alloy springs connected between two adjacent folding structures. The stretching or contraction of the first shape memory alloy spring drives the plurality of folding structures to stretch or bend as a whole, thereby realizing the switching of suction cup adsorption and desorption. The bottom surface of the lip ring has a micro-nano structure for limiting the retreat of the lip ring.

[0009] The structural characteristics of the present invention also lie in:

[0010] In the initial state, the two groups of flexible spine subsystems are symmetrically arranged front to back and can rotate relative to each other along the horizontal plane through the rotating connecting piece.

[0011] In the flexible spine subsystem:

[0012] The end of the inner moving cylinder exposed outside the outer sleeve and the rotating connecting piece, as well as the end of the cylinder on the closed side of the outer sleeve and the fixed connecting piece, are connected respectively by a plurality of inclined cylinders which are equally spaced and distributed along the circumferential direction and have a radial structure that diverges outwards as a whole;

[0013] The inner moving cylinder is a stepped shaft structure, and a matching stepped hole is formed in the outer sleeve. The inner moving cylinder is sleeved in the stepped hole with its small end facing the outer sleeve. One end of the return spring is coaxially sleeved outside the small end of the inner moving cylinder, and the other end is fixedly connected to the bottom of the stepped hole of the outer sleeve.

[0014] The return spring is a steel spring.

[0015] In the flexible driving module:

[0016] The flexible belt is provided with connection blocks for connecting with the fixed connection piece and the rotating connection piece at both ends along the belt length.

[0017] The shape memory alloy wire and the flexible belt are cast in one piece, and the flexible belt is made of a flexible material.

[0018] In the bionic suction cup system:

[0019] The unfolding structure is in the shape of a slender column, made of soft material, initially inclined, with one end connected to the lip ring facing backwards;

[0020] The lip ring is a semi-elliptical film with a straight edge connected to the suction cup;

[0021] An elastic film is arranged at the upper end of the adsorption cavity of the suction cup, and the elastic film is connected to the suction cup shell through a second shape memory alloy spring which is arranged vertically and can shrink when heated. The elastic film is pulled up by the contraction of the second shape memory alloy spring to realize the adsorption of the suction cup.

[0022] The micro-nano structure is a wedge-shaped structure, and the array is distributed on the bottom surface of the lip ring, with the tip facing the wall, the oblique end facing forward, and the straight end facing backward.

[0023] The rotating connecting member is assembled from an upper rotating disk and a lower rotating disk which are stacked up and rotatably connected via a rotating shaft arranged along the central axis of the disk body. One of the upper rotating disk and the lower rotating disk is connected to the flexible spine subsystem and the matching flexible driving module on the front side, and the other is connected to the flexible spine subsystem and the matching flexible driving module on the rear side.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The present invention is a soft wall-climbing robot based on negative pressure adsorption, which uses a suction cup to adsorb smooth wall surfaces, and uses a flexible folding structure to achieve crawling on vertical wall surfaces. Among them, the two flexible spine subsystems of the flexible spine system are rotationally connected and relatively independent. A flexible driving module is used to provide a motion driving force for the flexible spine system. The first shape memory alloy spring of the flexible spine subsystem and the second shape memory alloy spring in the suction cup shrink when heated to achieve adsorption and desorption of the suction cup, and to improve the adsorption force of the suction cup on the smooth wall surface. The folding structure and the micro-nano structure on the bottom of the lip ring make the robot body always keep moving forward when the lip ring and the wall surface generate friction. The present invention solves the problem that traditional wall-climbing robots cannot adsorb on smooth top surfaces upside down, and cannot crawl at any azimuth angle on vertical walls. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the flexible spine subsystem;

[0028] Figure 3 It is a schematic diagram of the internal structure of the flexible spine subsystem;

[0029] Figure 4 is a structural diagram of the flexible drive module;

[0030] Figure 5 It is a schematic diagram of the structure of the bionic suction cup system;

[0031] Figure 6 It is a schematic diagram of the internal structure of the suction cup;

[0032] Figure 7 is a schematic diagram of the micro-nano structure on the bottom surface of the lip ring;

[0033] Figure 8 It is a structural schematic diagram of an upper rotating disk in a rotating connecting member;

[0034] Fig. 9 This is the schematic diagram of the robot's linear motion;

[0035] Fig.10 This is the schematic diagram of the robot's steering motion;

[0036] Fig.11 It is the attachment model of the suction cup in active motion situation;

[0037] Fig.12 It is the working schematic diagram of the flexible drive module;

[0038] Fig.13 It is a diagram illustrating the motion of the flexible spine subsystem.

[0039] In the figure:

[0040] 1 flexible spine subsystem; 11 external sleeve; 12 internal moving cylinder; 13 return spring; 14 inclined cylinder;

[0041] 2 flexible driving module; 21 flexible belt; 22 shape memory alloy wire; 23 connecting block;

[0042] 3 Bionic suction cup system; 31 suction cup; 32 suction cup shell; 33 adsorption chamber; 34 second shape memory alloy spring; 35 elastic film; 36 lip ring; 37 micro-nano structure; 38 unfolding structure; 39 first shape memory alloy spring;

[0043] 4. Fix the connecting parts;

[0044] 5 rotating connecting member; 51 upper rotating disk;

[0045] 6 walls. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. 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.

[0047] The design of the present invention is inspired by the rock loach in Guizhou. The rock loach-imitating soft wall-climbing robot has a flexible spine system, which is composed of flexible materials and shape memory alloys. When the input excites the flexible spine, it bends and contracts. In order to make the robot stably adsorbed on the wall, the flexible suction cup can be fixed to the lower end of the flexible spine subsystem through a 3D printed part. The suction cup is filled with shape memory alloys, which generate torque on the lip when heated, increase the seal and reduce air leakage. The robot also includes a fin-like folding structure. The micro-nano structure on the surface of the lip ring is anisotropic, so that when the folding structure rubs against the wall, the body can only move in a single direction. By designing a suitable gait, the robot can achieve linear and turning movements on a vertical wall.

[0048] Please refer to Figures 1 to 8 The rock loach-like soft wall-climbing robot of this embodiment includes a flexible spine system consisting of two groups of flexible spine subsystems 1 arranged one in front of the other and rotatably connected by a rotating connector 5, and also includes a flexible driving module 2 and a bionic suction cup system 3 configured for each group of flexible spine subsystems 1;

[0049] The flexible spine subsystem 1 comprises an outer sleeve 11 and an inner moving cylinder 12 which are coaxially mounted and connected with a reset spring 13. The end of the outer sleeve 11 faces the fixed connecting member 4 and is connected thereto. The end of the inner moving cylinder 12 faces the rotating connecting member 5 and is connected thereto. The outer sleeve 11 can be extended and retracted axially relative to the outer sleeve 11 by the drive of the flexible driving module 2 and can be reset by the reset spring 13.

[0050] The flexible driving module 2 comprises a pair of flexible belts 21 in an arc-shaped belt structure, which are respectively arranged on the left and right sides of the flexible spine subsystem 1. The pair of flexible belts 21 face each other with inner concave surfaces and surround the flexible spine subsystem 1, and are respectively connected between the fixed connector 4 and the rotating connector 5 at both ends of the flexible spine subsystem 1. The flexible belts 21 are embedded with heat-shrinkable shape memory alloy wires 22 arranged along the entire length of the belt body. The flexible belts 21 are bendable, and the bending degree of the flexible belts 21 on either side increases with the shrinkage of the shape memory alloy wires 22. The force generated by the bending deformation serves as the driving force of the flexible spine subsystem 1.

[0051] The bionic suction cup system 3 is arranged at the bottom of the outer sleeve 11, and includes a suction cup 31 with the adsorption surface facing downward, a pair of symmetrically arranged lip rings 36 extending on the left and right sides of the suction cup 31, a plurality of front-to-back spaced folding structures 38 connected between the lip ring 36 and the upper end of the suction cup 31, and a plurality of heat-shrinkable first shape memory alloy springs 39 connected between two adjacent folding structures 38. The stretching or contraction of the first shape memory alloy springs 39 drives the plurality of folding structures 38 to stretch or bend as a whole, thereby realizing the switching of adsorption and desorption of the suction cup 31. The bottom surface of the lip ring 36 has an anisotropic micro-nano structure 37, which is used to limit the retreat of the lip ring 36.

[0052] The corresponding structural setting of the wall-climbing robot also includes:

[0053] In the initial state, the two groups of flexible spine subsystems 1 are symmetrically arranged front to back and can rotate relative to each other along the horizontal plane through the rotating connecting member 5.

[0054] In the flexible spine subsystem 1:

[0055] The inner moving cylinder 12 is connected between the cylinder end exposed outside the outer sleeve 11 and the rotating connecting member 5, and between the cylinder end on the closed side of the outer sleeve 11 and the fixed connecting member 4, respectively, through a plurality of inclined cylinders 14 which are equally spaced and distributed along the circumferential direction and have a radial structure that diverges outwards as a whole.

[0056] The inner moving cylinder 12 is a stepped shaft structure, and a corresponding stepped hole is formed in the outer sleeve 11. The inner moving cylinder 12 is sleeved in the stepped hole with its small end facing the outer sleeve 11. One end of the return spring 13 is coaxially sleeved outside the small end of the inner moving cylinder 12, and the other end is fixedly connected to the bottom of the stepped hole of the outer sleeve 11.

[0057] The inclined cylinder 14 and the inner moving cylinder 12 as well as the outer sleeve 11 can be integrally formed by 3D printing technology.

[0058] The return spring 13 is a steel spring.

[0059] In the flexible driving module 2: the flexible belt 21 is provided with connecting blocks 23 for connecting with the fixed connecting member 4 and the rotating connecting member 5 along the two ends of the belt length. The connecting blocks 23 can be bonded and connected to the cured flexible belt 21 by strong glue. The connecting block 23 for connecting with the fixed connecting member 4 has a screw hole, and is fastened to the fixed connecting member 4 by bolts. The connecting block 23 for connecting with the rotating connecting member 5 has a slot with a screw hole, and is plugged into the protrusion on the rotating connecting member 5 through the slot and fastened by bolts.

[0060] The shape memory alloy wire 22 and the flexible belt 21 are integrally cast, and the flexible belt 21 is made of a flexible material. In this embodiment, the flexible belt 21 is made of PDMS.

[0061] PCB circuit boards are embedded at both ends of the flexible belt 21. The shape memory alloy wire 22 is wound between the two PCB circuit boards along the length of the belt and connected to the PCB circuit boards. The interface end of the PCB circuit board for connecting to an external DC power supply is exposed outside the flexible belt 21. The DC power supply is used to power the shape memory alloy wire 22. When power is turned on, the shape memory alloy wire 22 shrinks due to heat. Figure 4 .

[0062] Bionic Suction Cup System 3:

[0063] The folding structure 38 is in the shape of a slender column. The folding structures 38 form a fish-fin-like structure as a whole. The folding structure 38 is made of soft material and is initially tilted, with one end connected to the lip ring 36 facing backward. In this embodiment, the folding structure 38 is made of polyurethane.

[0064] The lip ring 36 is a semi-elliptical film with a straight edge connected to the suction cup 31;

[0065] An elastic film 35 is provided at the upper end of the adsorption chamber 33 of the suction cup 31. The elastic film 35 is connected to the suction cup shell 32 through a second shape memory alloy spring 34 which is vertically arranged and shrinkable when heated. The lower end of the second shape memory alloy spring 34 is embedded in the elastic film 35. The second shape memory alloy spring 34 shrinks when heated to pull the elastic film 35 upward, and the elastic film 35 arches upward, thereby generating a local vacuum in the sealed adsorption chamber 33, generating a coupling effect on the lip of the suction cup 31, thereby enhancing the adsorption capacity of the suction cup 31 and achieving stable adsorption of the suction cup 31.

[0066] During production, the folding structure 38 can be directly demolded and integrated with the lip ring 36 and the suction cup 31. When the folding structure 38 moves, the lip ring 36 and the suction cup 31 connected thereto are pulled to move. When the lip ring 36 moves, the lip edge of the suction cavity 33 of the suction cup 31 will be lifted and leak, thereby achieving the overall desorption of the suction cup 31.

[0067] The micro-nano structure 37 has a scale of micrometer to nanometer, and is in a wedge-shaped structure. The array is distributed on the bottom surface of the lip ring 36, with the tip facing the wall 6, the oblique end facing forward, and the straight end facing backward. The active contraction of the first shape memory alloy spring 39 drives the change of the state of the unfolding structure 38 to drive the suction cup 31 to move. When the multiple unfolding structures 38 turn from the bending state to the stretching state, the anisotropy of the micro-nano structure 37 on the bottom surface of the lip ring 36 generates a friction force between it and the wall 6 to prevent the unfolding structure 38 from restoring along the original path, and realizes the unidirectional movement of the lip ring 36. The friction force reacts to the robot to drive the suction cup 31 to slide on the smooth surface.

[0068] The rotating connection member 5 is assembled from an upper rotating disk 51 and a lower rotating disk stacked up and rotatably connected via a rotating shaft arranged along the central axis of the disk body. One of the upper rotating disk 51 and the lower rotating disk is connected to the front flexible spine subsystem 1 and the matching flexible driving module 2, and the other is connected to the rear flexible spine subsystem 1 and the matching flexible driving module 2. By setting the rotating connection member 5, the two flexible spine subsystems 1 have relative independence, which is convenient for the robot to realize steering operation.

[0069] The first shape memory alloy spring 39 and the second shape memory alloy spring 34 are connected to an external DC power supply respectively, and shrink when powered on. The power supply principle is similar to that of the shape memory alloy wire 22 .

[0070] Movement principle:

[0071] In the bionic suction cup system 3, when the first shape memory alloy spring 39 on one side of the suction cup 31 shrinks due to heat, the first shape memory alloy spring 39 pulls each folding structure 38 to move horizontally, and the folding structure 38 is connected to the lip ring 36. The lip ring 36 is warped by the horizontal movement of the folding structure 38, and the warping of the lip ring 36 causes the adsorption cavity 33 of the suction cup 31 to leak, thereby realizing the desorption movement of the suction cup 31. When the first shape memory alloy spring 39 stops shrinking due to heat and returns to its original state, the first shape memory alloy spring 39 pushes the folding structure 38 to continue to move horizontally through the anisotropic friction force of the micro-nano structure 37 on the bottom surface of the lip ring 36, thereby realizing the steering movement of the robot, and the lip ring 36 is stretched through the continued horizontal movement of the folding structure 38, realizing the adsorption movement of the suction cup 31.

[0072] In the flexible driving module 2, the shape memory alloy wire 22 undergoes a phase change due to heat to produce axial contraction, pulling the two ends of the flexible belt 21 to warp. The flexible belt 21 transmits the bending moment and force to the flexible spine subsystem 1 through the connecting blocks 23 at both ends.

[0073] In the flexible spine subsystem 1, the force of the flexible driving module 2 is transmitted to the external sleeve 11 and the internal moving cylinder 12. The external sleeve 11 and the internal moving cylinder 12 have independent movement space to avoid mutual interference. Through the extrusion of the flexible driving module 2, the internal moving cylinder 12 moves axially in the external sleeve 11 to realize the linear motion of the robot.

[0074] Based on the above, the robot can switch between linear motion and steering motion modes:

[0075] When the motion mode is linear motion, the suction cup 31 at the front end is required to maintain stable adsorption, and the suction cup 31 at the rear end is required to maintain a desorption state through the heat contraction of the first shape memory alloy spring 39. The shape memory alloy wire 22 is heated and contracted, driving the flexible belt 21 to warp, and the generated bending moment and force are transmitted to the outer sleeve 11 and the inner moving cylinder 12. The inner moving cylinder 12 moves axially in the outer sleeve 11, pulling the suction cup 31 at the rear end, and realizing the linear motion of the robot on the vertical wall 6;

[0076] When the motion mode is a turning motion, the suction cup 31 at the rear end is required to be stably adsorbed, and the suction cup 31 at the front end is kept in a desorbed state by the heat contraction of the first shape memory alloy spring 39. By causing the first shape memory alloy spring 39 on one side of the front suction cup 31 to contract due to heat, the front suction cup 31 is pulled to move along one side by its contraction, at which time the front suction cup 31 is warped, and the first shape memory alloy spring 39 stops contracting due to heat and returns to its original shape, pushing the front suction cup 31 to continue to move along one side, at which time the front suction cup 31 is relaxed, completing the turning motion.

[0077] Fig.11 is the attachment model of the suction cup 31 in the active motion condition. When the robot moves on the wall 6, F 1 is the desorption force of the vertical suction cup 31, and the suction cup 31 is subjected to the external air pressure P a and the intracavitary pressure P b The extrusion force F is applied to the lip 36 in contact with the substrate. 2 During the desorption process, the lip ring 36 slides tangentially, and the substrate provides a friction force F on the suction cup 31. f The first shape memory alloy spring 39 contracts, and the suction cup 31 is subjected to a tensile force F sma .

[0078] Fig.12 This is a schematic diagram of the working of the flexible driving module 2. By heating the shape memory alloy wire 22, the flexible belt 21 is warped and deviates from the initial position, and a pressure F is generated along the x-coordinate direction at the end connected to the fixed connecting member 4. 4 , there is a free warping force F at the free end 3 The components of the warping force in the x and y coordinate directions are F 3x 、F 3y By stopping the heating of the shape memory alloy wire 22, the flexible band 21 returns to its original position after cooling.

[0079] Fig.13 1 is a motion diagram of the flexible spine subsystem 1. Through the contraction of the flexible driving module 2, the external sleeve 11 is subjected to the force of the flexible driving module 2 in the x and y coordinate directions. 3x 、F 5x 、F3y 、F 5y The internal moving cylinder 12 is subjected to the force of the flexible driving module 2 in the x and y coordinate directions, respectively. 4x 、F 6x 、F 4y 、F 6y , F 3 、F 5 is the extrusion force on the outer sleeve 11, F 4 、F 6 is the squeezing force on the inner moving cylinder 12.

[0080] Application examples:

[0081] See also Fig. 9 , the linear motion of the robot can be disassembled into three steps. The solid arrow in the figure indicates the forward direction of the robot, and the three steps are performed in sequence according to the direction of the hollow arrow. Before the movement starts, the front suction cup 31 and the rear suction cup 31 of the robot are both in a non-adsorbed state. When the linear motion starts, the shape memory alloy wire 22 in the flexible driving module 2 on both sides of the rear end of the suction cup 31 is first energized, and the front suction cup 31 is set to the adsorption state at the same time. At this time, the rear suction cup 31 moves forward under the traction of the flexible driving module 2. When the flexible belt 21 of the flexible driving module 2 is bent to the maximum angle, the rear suction cup 31 is set to the adsorption state, and the front suction cup 31 is set to the non-adsorbed state. At this time, the front suction cup 31 will move forward under the thrust of the flexible spine subsystem 1.

[0082] See also Fig.10 , the robot's steering movement can be disassembled into 5 steps. The solid arrow in the figure indicates the robot's forward direction, and the 5 steps are performed in sequence according to the direction of the hollow arrow. Here, taking right steering as an example, before the movement starts, the robot's front suction cup 31 and the rear suction cup 31 are both in a non-adsorbed state. When starting the steering movement, first energize the shape memory alloy wire 22 in the flexible drive module 2 on both sides of the rear suction cup 31, and set the front suction cup 31 to the adsorption state at the same time. At this time, the rear suction cup 31 moves forward under the traction of the flexible drive module 2. Set the rear suction cup 31 to the adsorption state, and set the front suction cup 31 to the non-adsorbed state at the same time to prepare for steering. Activate the flexible drive module 2 on the right side of the front suction cup 31, and at this time, the front suction cup 31 deflects to the right under the action of the tension. Finally, set the rear suction cup 31 to the non-adsorbed state, the rear flexible spine subsystem 1 is stretched, and the front suction cup 31 continues to deflect to the right under the thrust of the flexible spine subsystem 1 to complete the steering movement.

[0083] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A soft wall-climbing robot imitating a rock loach, Its characteristics are: A flexible spine system comprising two groups of flexible spine subsystems arranged one in front of the other and rotatably connected via a rotating connector, and also comprising a flexible driving module and a bionic suction cup system configured for each group of flexible spine subsystems; The flexible spine subsystem comprises an outer sleeve and an inner moving cylinder coaxially mounted and connected with a reset spring, the end of the outer sleeve facing the fixed connecting piece and connected, the end of the inner moving cylinder facing the rotating connecting piece and connected, and can be axially retracted relative to the outer sleeve by the drive of the flexible driving module, and can be reset by the reset spring; The flexible driving module comprises a pair of flexible belts in an arc-shaped belt structure, which are respectively arranged on the left and right sides of the flexible spine subsystem. The pair of flexible belts face each other with inner concave surfaces and surround the flexible spine subsystem, and are respectively connected between the fixed connector and the rotating connector at both ends of the flexible spine subsystem. The flexible belts are embedded with heat-shrinkable shape memory alloy wires arranged along the entire length of the belt body. The flexible belts are bendable, and the bending degree of the flexible belts on either side increases with the shrinkage of the shape memory alloy wires. The force generated by the bending deformation serves as the driving force of the flexible spine subsystem. The bionic suction cup system is arranged at the bottom of the outer sleeve, and includes a suction cup with an adsorption surface facing downward, a pair of symmetrically arranged lip rings extending on the left and right sides of the suction cup, a plurality of front-to-back spaced folding structures connected between the lip ring and the upper end of the suction cup, and a plurality of heat-shrinkable first shape memory alloy springs connected between two adjacent folding structures. Through the stretching or contraction of the first shape memory alloy springs, the plurality of folding structures are driven to stretch or bend as a whole, so as to realize the switching between adsorption and desorption of the suction cup. The bottom surface of the lip ring has a micro-nano structure for limiting the retreat of the lip ring. The unfolding structure is in the shape of a slender column and is made of soft material. It is initially inclined, with one end connected to the lip ring facing backwards. The lip ring is a semi-elliptical film, and the straight edge is connected to the suction cup. An elastic film is arranged at the upper end of the suction chamber of the suction cup, and the elastic film is connected to the suction cup shell through a second shape memory alloy spring that is vertically arranged and shrinkable when heated. The second shape memory alloy spring shrinks to form an upward pull on the elastic film, thereby realizing the suction of the suction cup. The micro-nano structure is a wedge-shaped structure, and the array is distributed on the bottom surface of the lip ring, with the tip facing the wall, the oblique end facing forward, and the straight end facing backward.

2. The soft wall-climbing robot imitating a rock loach according to claim 1, Its characteristics are: In the initial state, the two groups of flexible spine subsystems are symmetrically arranged front to back and can rotate relative to each other along the horizontal plane through the rotating connecting piece.

3. The soft wall-climbing robot imitating rock loach according to claim 1, Its characteristics are: In the flexible spine subsystem: The end of the inner moving cylinder exposed outside the outer sleeve and the rotating connecting piece, as well as the end of the cylinder on the closed side of the outer sleeve and the fixed connecting piece, are connected respectively by a plurality of inclined cylinders which are equally spaced and distributed along the circumferential direction and have a radial structure that diverges outwards as a whole; The inner moving cylinder is a stepped shaft structure, and a matching stepped hole is formed in the outer sleeve. The inner moving cylinder is sleeved in the stepped hole with its small end facing the outer sleeve. One end of the return spring is coaxially sleeved outside the small end of the inner moving cylinder, and the other end is fixedly connected to the bottom of the stepped hole of the outer sleeve.

4. The soft wall-climbing robot imitating a rock loach according to claim 1 or 3, Its characteristics are: The return spring is a steel spring.

5. The rock loach-like soft wall-climbing robot according to claim 1, Its characteristics are: In the flexible driving module: The flexible belt is provided with connection blocks for connecting with the fixed connection piece and the rotating connection piece at both ends along the belt length.

6. The rock loach-like soft wall-climbing robot according to claim 1, Its characteristics are: The shape memory alloy wire and the flexible belt are cast in one piece, and the flexible belt is made of a flexible material.

7. The rock loach-like soft wall-climbing robot according to claim 1, Its characteristics are: The rotating connecting member is assembled from an upper rotating disk and a lower rotating disk which are stacked up and rotatably connected via a rotating shaft arranged along the central axis of the disk body. One of the upper rotating disk and the lower rotating disk is connected to the flexible spine subsystem and the matching flexible driving module on the front side, and the other is connected to the flexible spine subsystem and the matching flexible driving module on the rear side.

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