Drilling soft robot and drilling method

Abstract

The invention discloses a drilling soft-bodied robot and a drilling method.The drilling soft-bodied robot comprises a trunk part, a head part and a tail part, the trunk part comprises a head scaling ring, a tail scaling ring and a driving part, and the head scaling ring and the tail scaling ring are connected through a soft-bodied pipe; the head part comprises a head supporting ring and a drilling ring which are sequentially arranged, the tail part comprises a tail supporting ring, the head scaling ring, the tail scaling ring, the head supporting ring, the drilling ring and the tail supporting ring are all made of chiral metamaterials, and the flexible pipe is made of folded metamaterials. The motor drives the chiral metamaterials of the head part and the tail part to deform, creeping of the folded metamaterials of the trunk part in the axial direction is achieved, then creeping drilling of the robot in the axial direction is achieved, the drilling robot is simple in structure and capable of adapting to operation in a narrow space, disturbance to the soil environment during creeping advancing is small, and the working efficiency of the robot is improved. And the device is suitable for fine operation of underground soil.

Description

Technical Field

[0001] The present invention relates to the field of underground drilling robots, and more particularly, to a drilling soft robot and a drilling method. Background Art

[0002] Traditional robots, due to their rigid structures and limited degrees of freedom, often struggle to cope with complex and changing working environments, particularly in tasks requiring high flexibility and precision manipulation. In contrast, soft robots, as an emerging technology, demonstrate enormous application potential in a number of key areas thanks to their unique high flexibility and excellent adaptability. Soft robots offer significant advantages over traditional robots, particularly in refined operations in underground spaces. For example, during the installation of sensors in deep formations, soil disturbance is unavoidable, affecting not only the accuracy of data collection but also the validity and reliability of subsequent analysis results. To ensure the authenticity and accuracy of monitoring data, soil disturbance during installation must be minimized.

[0003] Invention patent CN104727749B discloses a peristaltic drilling robot, which includes an electric push rod mechanism, a motor steering mechanism, and a drill bit mechanism connected in sequence. The invention provides a scale device for opening and contracting on the outer walls of the electric push rod mechanism and the drill bit mechanism respectively. The electric push rod mechanism periodically expands and contracts, and the scale device opens or contracts under the action of soil force to provide a supporting reaction force in the drilling direction. The device provides power output through the scale device, and the scale needs to open and contract frequently, which will cause large continuous disturbance to the soil on its movement path. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an innovative drilling soft robot, which drives the expansion and contraction deformation of each component through a motor to achieve axial creep and thus perform drilling tasks.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A drilling soft robot comprises a trunk component, a head component and a tail component connected to both ends of the trunk component; the trunk component comprises a head scaling ring, a tail scaling ring, and a driving component, the driving component comprising a driving motor and a telescopic transmission shaft connected to the driving motor, the head scaling ring and the tail scaling ring are connected to the telescopic transmission shaft, the head scaling ring and the tail scaling ring are connected by a soft tube, the outer periphery of the soft tube is also wrapped with a skin shell; the head component comprises a head support ring and a drilling ring connected to the telescopic transmission shaft in sequence, the drilling ring is composed of a plurality of deformable rings with gradually decreasing radii, and the head support ring and the drilling ring are also wrapped with a skin shell; the tail component comprises a tail support ring connected to the telescopic transmission shaft and a skin shell wrapped around the tail support ring; the head scaling ring, the tail scaling ring, the head support ring, the drilling ring, and the tail support ring are all made of chiral metamaterials, and the soft tube is a folded metamaterial.

[0007] Furthermore, the chiral metamaterial is a six-ligament chiral structure, including a central ring and ligaments, a central ring gear is provided on the inner side of the central ring, and the gear is engaged with the telescopic transmission shaft; the outer side of the central ring is tangent to the ligament.

[0008] Furthermore, the unit cell structure of the folded metamaterial is a concave quadrilateral folded structure.

[0009] Furthermore, the telescopic transmission shaft includes a head telescopic transmission shaft connected to the head component and a tail telescopic transmission shaft connected to the tail component, and the head telescopic transmission shaft and the tail telescopic transmission shaft are meshed with the drive motor gear through a straight bevel gear.

[0010] Furthermore, the overall appearance of the multiple deformation rings with gradually decreasing radii is in the shape of a tapered drill bit.

[0011] Furthermore, gaps exist between the multiple deformation rings with gradually decreasing radii, which are connected by the skin shell.

[0012] A drilling method for a drilling soft robot comprises the following steps:

[0013] S1, the drilling soft robot is in the initial state, and all its components are in a free state;

[0014] S2, drilling stage: the driving motor rotates forward, driving the tail telescopic drive shaft to rotate clockwise, thereby driving the chiral metamaterial of the tail support ring of the tail component to rotate clockwise, causing the tail support ring to radially expand and embed into the soil layer. At the same time, the head scaling ring of the trunk component, the chiral metamaterial of the tail scaling ring, and the chiral metamaterial of the drilling ring and the head support ring of the head component rotate counterclockwise, causing the head scaling ring, tail scaling ring, drilling ring, and head support ring to radially shrink, thereby driving the folded metamaterial of the soft tube to extend toward the head direction;

[0015] S3, recovery phase: the driving motor rotates forward and reverse, driving the telescopic drive shaft of the head to rotate clockwise, thereby driving the chiral metamaterial of the head support ring of the head component to rotate clockwise, causing the head support ring to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring, tail scaling ring, and tail support ring of the torso component rotate counterclockwise, causing the head scaling ring, tail scaling ring, and tail support ring of the tail component to radially shrink to a free state, thereby driving the folded metamaterial of the soft tube to shorten toward the head direction;

[0016] S4. The driving motor is in a free state, so that the head support ring returns to a free state, and the drilling soft robot completes a cycle.

[0017] Furthermore, the overall scaling range of the chiral metamaterial is λ∈[λ1,λ2], λ1<1,λ2>1; and the Poisson's ratio of the concave quadrilateral folding structure of the soft tube is ν∈[-1,1].

[0018] Furthermore, in the initial stage S1, the cone angle formed by the head drilling ring is α0, the length of the soft tube is L0, the radius is r0, and the radius of the tail scaling ring, tail support ring, head scaling ring, and head support ring is r0; in the S2 drilling stage, the drilling ring of the head component is reduced in proportion to achieve a variable cone angle wedging into the soil. At this time, the cone angle is α, the radius of the tail support ring is enlarged to λ2r0, and the radii of the tail scaling ring and the head scaling ring are reduced to λ1r0, driving the radius of the soft tube of the torso component to be reduced to λ1r0, and the length is extended to ν[(1-λ1)+1]L0; in the S3 recovery stage, the head support ring is enlarged to λ2r0, the drilling ring is restored to the cone angle of α0, and the torso and tail components are restored to their initial size. At this time, the forward length of the soft robot is v(1-λ1)L0.

[0019] Furthermore, when the folding angle θ of the unit cell structure of the concave quadrilateral folding is 135°, the Poisson's ratio ν reaches a maximum value of 1, and the forward length of the drilling soft robot reaches the longest.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention uses a motor to drive the deformation of the chiral metamaterial of the head and tail components to achieve axial creep of the folded metamaterial of the torso component, thereby achieving axial creep drilling of the robot. The drilling robot has a simple structure and can adapt to operations in narrow spaces. It causes little disturbance to the soil environment during creeping forward and is suitable for refined operations in underground soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of a drilling soft robot;

[0023] Figure 2This is a longitudinal cross-sectional view of the structure of a drilling soft robot;

[0024] Figure 3 This is the deformation diagram of the cross section of the chiral metamaterial;

[0025] Figure 4 It is the deformation diagram of the concave quadrilateral folded unit cell;

[0026] Figure 5 This is the assembly diagram of the chiral metamaterial and the telescopic transmission shaft;

[0027] Figure 6 This is a diagram of the gait steps of a drilling soft robot in one cycle of forward motion.

[0028] Among them: 1. Tail component; 11. Tail support ring; 12. Tail skin shell; 2. Trunk component; 21. Tail scaling ring; 22. Head scaling ring; 23. Trunk skin shell; 24. Drive motor; 25. Telescopic transmission shaft; 26. Soft tube; 27. Concave quadrilateral folding structure; 28. Straight bevel gear; 29. ​​Straight bevel pinion; 3. Head part; 31. Head support ring; 32. Head skin shell; 33. Drilling ring; 4. Six-ligament chiral structure; 41. Center ring gear. DETAILED DESCRIPTION

[0029] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0030] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent actual sizes. For those skilled in the art, it is understandable that some well-known contents in the drawings may be omitted. The technical solution of the present invention is further explained below in conjunction with the drawings and embodiments.

[0031] Example 1

[0032] according to Figures 1 to 6 This embodiment provides a drilling soft robot, comprising a trunk component 2, a head component 3 connected to both ends of the trunk component, and a tail component 1;

[0033] The torso component includes a head scaling ring 22, a tail scaling ring 21, and a drive component. The drive component includes a drive motor 24 and a telescopic transmission shaft 25 connected to the drive motor 24. The head scaling ring 22 and the tail scaling ring 21 are connected to the telescopic transmission shaft 25. The telescopic transmission shaft 25 includes a head telescopic transmission shaft connected to the head component and a tail telescopic transmission shaft connected to the tail component. The head telescopic transmission shaft and the tail telescopic transmission shaft mesh with the spur bevel gear 28 of the drive motor via a spur bevel pinion 29, enabling a single motor to output both forward and reverse rotation.

[0034] The head scaling ring 22 and the tail scaling ring 21 are connected by a soft tube 26. The soft tube 26 is a folded metamaterial, and its unit cell structure is a concave quadrilateral folded structure 27. When the driving motor 24 drives the head scaling ring 22 and the tail scaling ring 21 to shrink synchronously, the soft tube 26 extends; when the driving motor 24 drives the head scaling ring 22 and the tail scaling ring 21 to recover synchronously, the soft tube 26 shrinks to its original length. The outer periphery of the soft tube 26 is also wrapped with a torso skin shell 23, which is convenient for protecting the entire torso when the soft tube 26 shrinks.

[0035] The head component 3 includes a head support ring 31 and a drilling ring 33 which are sequentially connected to the telescopic transmission shaft 25. The drilling ring 33 is composed of a plurality of deformable rings with gradually decreasing radii. The overall shape of the plurality of deformable rings with gradually decreasing radii is in the shape of a tapered drill bit to reduce resistance during drilling. Gaps are provided between the plurality of deformable rings with gradually decreasing radii and are connected through the head skin shell 32. The gaps have a certain degree of mobility during telescoping to prevent jamming.

[0036] The tail component 1 includes a tail support ring 11 connected to the telescopic transmission shaft 25 and a tail skin shell 12 wrapped around the tail support ring 11 .

[0037] The head scaling ring 22, tail scaling ring 21, head support ring 31, drilling ring 33, and tail support ring 11 are all chiral metamaterials, and the soft tube is a folded metamaterial. Specifically, the chiral metamaterial is a six-ligament chiral structure 4, which is composed of a ring and ligaments. A central ring gear 41 is arranged on the inner side of the ring at the center of the structure. The central ring gear 41 meshes with the gear of the telescopic transmission shaft 25 and is tangential to the ligament on the outer side. In the initial state, the ligament consists of two tangential arcs with a radius of r and a central angle of α, and can be straightened or curled. The rotation of the motor drives the central ring to rotate clockwise or counterclockwise, which in turn drives the ligament to rotate, straighten or curl, causing the lateral size of the structure to increase or decrease.

[0038] When the motor is driven, the head telescopic transmission shaft reverses, and the tail telescopic transmission shaft rotates forward. The drilling ring 33 of the head component is reduced in the same proportion to form a pointed cone shape, and the tail support ring 11 of the tail component is enlarged and embedded in the soil to provide greater supporting force. The head scaling ring 22 and the tail scaling ring 21 are reduced synchronously, driving the trunk component soft tube 26 to shrink radially and extend axially toward the head. Subsequently, the motor rotates in the opposite direction, the head telescopic transmission shaft rotates forward, and the tail telescopic transmission shaft reverses, the head support ring 31 of the head component is enlarged to provide greater supporting force, and the other components of the soft robot return to their initial state. At this time, the soft tube 26 of the trunk component returns to its original length toward the head, and the robot moves toward the head.

[0039] Example 2

[0040] This embodiment provides an embodiment, according to the drilling method of the drilling soft robot in embodiment 1, comprising the following steps:

[0041] S1. The drilling soft robot is in the initial state, and all its components are in a free state.

[0042] S2, drilling stage: the drive motor rotates forward, driving the tail telescopic drive shaft to rotate clockwise, thereby driving the chiral metamaterial of the tail support ring of the tail component to rotate clockwise, causing the tail support ring 11 to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring 22 and the tail scaling ring 21 of the torso component and the chiral metamaterial of the drilling ring 33 and the head support ring 31 of the head component rotate counterclockwise, causing the head scaling ring 22, the tail scaling ring 21 and the drilling ring 33, and the head support ring 31 to radially shrink, thereby driving the folded metamaterial of the soft tube 26 to extend toward the head.

[0043] S3, recovery phase: the driving motor rotates forward and reverse, driving the head telescopic transmission shaft to rotate clockwise, thereby driving the chiral metamaterial of the head support ring 31 of the head component to rotate clockwise, causing the head support ring 31 to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring 22, the tail scaling ring 21 and the tail support ring 11 of the torso component rotate counterclockwise, causing the head scaling ring 22, the tail scaling ring 21 and the tail support ring 21 of the tail component to radially shrink to a free state, thereby driving the folded metamaterial of the soft tube 26 to shorten toward the head direction.

[0044] S4. The driving motor is in a free state, so that the head support ring 31 returns to a free state, and the drilling soft robot completes a cycle.

[0045] The soft tube in the trunk component is made of a folded metamaterial. The unit cell structure of the folded metamaterial is a concave quadrilateral fold. By changing the inflection angle θ and stiffness ratio R of the unit cell structure, the Poisson's ratio ν and the Young's modulus E of the structure can be continuously controlled.

[0046] When the soft robot is made of steel, the unit cell structure is subjected to a uniformly distributed force in the horizontal direction during operation. Because the compression of the connecting rods between the unit cells is very small compared to the compression of the unit cells, the compression of the rods is ignored in the calculation. The structural Poisson's ratio is expressed as: The Young's modulus expression of the structure is: Where θ is the inner fold angle of the unit cell structure; E sis the Young's modulus of the material; t is the thickness of the concave quadrilateral unit cell; b is the width of the concave quadrilateral unit cell; and l is the length of the connecting rod and the unit cell edge. When θ < 71.6°, ν < 0; when θ > 71.6°, ν > 0; when θ = 45°, ν = -1; and when θ = 135°, ν = 1, the drilling soft robot reaches its maximum forward distance.

[0047] The overall scaling range of the chiral metamaterial is λ∈[λ1,λ2], λ1<1,λ2>1; the Poisson's ratio of the concave quadrilateral folding structure of the soft tube is ν∈[-1,1].

[0048] In the initial stage S1, the cone angle formed by the head drilling ring 33 is α0, the length of the soft tube is L0, the radius is r0, and the radius of the tail scaling ring 21, the tail support ring 11, the head scaling ring 22, and the head support ring 31 is r0; in the drilling stage S2, the head component drilling ring 33 is reduced in proportion to achieve a variable cone angle wedging into the soil. At this time, the cone angle is α, the radius of the tail support ring 11 is enlarged to λ2r0, and the radii of the tail scaling ring 21 and the head scaling ring 22 are reduced to λ1r0, driving the radius of the torso component soft tube 26 to be reduced to λ1r0, and the length is extended to ν[(1-λ1)+1]L0; in the recovery stage S3, the head support ring 31 is enlarged to λ2r0, the drilling ring is restored to the cone angle of α0, and the torso and tail components are restored to their initial size. At this time, the forward length of the soft robot is ν(1-λ1)L0.

[0049] Example 3

[0050] This embodiment provides an embodiment, according to the drilling method of the drilling soft robot in embodiment 1, comprising the following steps:

[0051] S1. The drilling soft robot is in the initial state, and all its components are in a free state.

[0052] S2, drilling stage: the drive motor rotates forward, driving the tail telescopic drive shaft to rotate clockwise, thereby driving the chiral metamaterial of the tail support ring of the tail component to rotate clockwise, causing the tail support ring 11 to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring 22 and the tail scaling ring 21 of the torso component and the chiral metamaterial of the drilling ring 33 and the head support ring 31 of the head component rotate counterclockwise, causing the head scaling ring 22, the tail scaling ring 21 and the drilling ring 33, and the head support ring 31 to radially shrink, thereby driving the folded metamaterial of the soft tube 26 to extend toward the head.

[0053] S3, recovery phase: the driving motor rotates forward and reverse, driving the head telescopic transmission shaft to rotate clockwise, thereby driving the chiral metamaterial of the head support ring 31 of the head component to rotate clockwise, causing the head support ring 31 to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring 22, the tail scaling ring 21 and the tail support ring 11 of the torso component rotate counterclockwise, causing the head scaling ring 22, the tail scaling ring 21 and the tail support ring 21 of the tail component to radially shrink to a free state, thereby driving the folded metamaterial of the soft tube 26 to shorten toward the head direction.

[0054] S4. The driving motor is in a free state, so that the head support ring 31 returns to a free state, and the drilling soft robot completes a cycle.

[0055] The soft tube in the trunk component is made of a folded metamaterial. The unit cell structure of the folded metamaterial is a concave quadrilateral fold. By changing the inflection angle θ and stiffness ratio R of the unit cell structure, the Poisson's ratio ν and the Young's modulus E of the structure can be continuously controlled.

[0056] When the soft robot is made of steel, the unit cell structure is subjected to a uniformly distributed force in the horizontal direction during operation. Because the compression of the connecting rods between the unit cells is very small compared to the compression of the unit cells, the compression of the rods is ignored in the calculation. The structural Poisson's ratio is expressed as: The Young's modulus expression of the structure is: Where θ is the inner fold angle of the unit cell structure; E s is the Young's modulus of the material; t is the thickness of the concave quadrilateral unit cell; b is the width of the concave quadrilateral unit cell; and l is the length of the connecting rod and the unit cell edge. When θ < 71.6°, ν < 0; when θ > 71.6°, ν > 0; when θ = 45°, ν = -1; and when θ = 135°, ν = 1, the drilling soft robot reaches its maximum forward distance.

[0057] The overall scaling range of the chiral metamaterial is λ∈[λ1,λ2], λ1<1,λ2>1; the Poisson's ratio of the concave quadrilateral folding structure of the soft tube is ν∈[-1,1].

[0058] In the initial stage S1, the cone angle formed by the head drilling ring 33 is α0, the length of the soft tube is L0, the radius is r0, and the radius of the tail scaling ring 21, the tail support ring 11, the head scaling ring 22, and the head support ring 31 is r0; in the drilling stage S2, the head component drilling ring 33 is reduced in proportion to achieve a variable cone angle wedging into the soil. At this time, the cone angle is α, the radius of the tail support ring 11 is enlarged to λ2r0, and the radii of the tail scaling ring 21 and the head scaling ring 22 are reduced to λ1r0, driving the radius of the torso component soft tube 26 to be reduced to λ1r0, and the length is extended to ν[(1-λ1)+1]L0; in the recovery stage S3, the head support ring 31 is enlarged to λ2r0, the drilling ring is restored to the cone angle of α0, and the torso and tail components are restored to their initial size. At this time, the forward length of the soft robot is ν(1-λ1)L0.

[0059] Furthermore, from an energy perspective, during the drilling phase, the radius of the tail support ring 11 is enlarged by λ2 times, the radius of the head scaling ring 22 and the tail scaling ring 21 is reduced by λ1 times, and the drilling ring 33 and the head support ring 31 of the head component are both reduced by λ1 times. Obviously, the support reaction force of the tail soil is greater than the support reaction force of the head soil, that is, the head scaling ring 22 moves the flexible tube 26 toward the head, and the extension amount is ν(1-λ1)L0. Assuming that the soil or sand in the forward direction undergoes non-uniform deformation, the deformation energy of the soil during the drilling phase is At this point, it is only necessary to calculate the external driving force T≥V1 provided by the motor to complete the drilling of the soft robot. During the recovery phase, the radius of the head scaling ring 22 is enlarged by λ2 times, and the tail component returns to its initial state. Obviously, the support reaction force of the head soil is greater than the support reaction force of the tail soil, causing the soft tube to shorten toward the head, and the shortening amount is ν(1-λ1)L0. The deformation energy of the soil during the recovery phase is The soil deformation energy in the recovery stage is provided by the elastic energy of the head scaling ring 22, the tail scaling ring 21 and the soft tube 26, where L0 is the initial length of the soft tube; r0 is the initial radius of the soft tube; ν is the Poisson's ratio of the material; R0 is the influence range of soil deformation; E s is the Young's modulus of the soil; γ is the non-uniform deformation coefficient of the soil; ε1 is the strain at the center of the soil during the drilling stage; ε2 is the strain at the center of the soil during the recovery stage.

[0060] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A drilling soft robot, characterized in that: It includes a trunk part, a head part and a tail part connected to both ends of the trunk part; The torso component includes a head zoom ring, a tail zoom ring, and a driving component. The driving component includes a driving motor and a telescopic transmission shaft connected to the driving motor. The head zoom ring and the tail zoom ring are connected to the telescopic transmission shaft. The head zoom ring and the tail zoom ring are connected by a soft tube. The outer periphery of the soft tube is also wrapped with a skin shell. The head component includes a head support ring and a drilling ring connected to the telescopic transmission shaft, the drilling ring is composed of a plurality of deformable rings with gradually decreasing radius, and the head support ring and the drilling ring are also wrapped with a skin shell; The tail component includes a tail support ring connected to the telescopic transmission shaft and a skin shell wrapped around the tail support ring; The head scaling ring, the tail scaling ring, the head supporting ring, the drilling ring, and the tail supporting ring are all made of chiral metamaterials, and the soft tube is made of folded metamaterials.

2. A drilling soft robot according to claim 1, characterized in that: The chiral metamaterial is a six-ligament chiral structure, including a central ring and ligaments. A central ring gear is arranged on the inner side of the central ring, and the gear is engaged with the telescopic transmission shaft; the outer side of the central ring is tangent to the ligament.

3. The drilling soft robot according to claim 1, characterized in that: The unit cell structure of the folded metamaterial is a concave quadrilateral folded structure.

4. The drilling soft robot according to claim 1, characterized in that: The telescopic transmission shaft includes a head telescopic transmission shaft connected to the head component and a tail telescopic transmission shaft connected to the tail component. The head telescopic transmission shaft and the tail telescopic transmission shaft are meshed with the drive motor gear through a straight bevel gear.

5. The drilling soft robot according to claim 1, characterized in that: The overall appearance of the multiple deformation rings with gradually decreasing radii is in the shape of a tapered drill bit.

6. The drilling soft robot according to claim 5, characterized in that: There are gaps between multiple deformation rings with gradually decreasing radii, which are connected by skin shells.

7. A drilling method for a drilling soft robot, applied to the drilling soft robot according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, the drilling soft robot is in the initial state, and all its components are in a free state; S2, drilling stage: The drive motor rotates forward, driving the tail telescopic drive shaft to rotate clockwise, thereby driving the chiral metamaterial of the tail support ring of the tail component to rotate clockwise, causing the tail support ring to radially expand and embed into the soil layer. At the same time, the head scaling ring of the torso component, the chiral metamaterial of the tail scaling ring, and the drilling ring of the head component and the chiral metamaterial of the head support ring rotate counterclockwise, causing the head scaling ring, tail scaling ring, drilling ring, and head support ring to radially shrink, thereby driving the folding metamaterial of the soft tube to extend toward the head. S3, recovery phase: The drive motor rotates forward and reverse, driving the telescopic drive shaft of the head to rotate clockwise, thereby driving the chiral metamaterial of the head support ring of the head component to rotate clockwise, causing the head support ring to radially expand and embed into the soil layer. At the same time, the chiral metamaterial of the head scaling ring, tail scaling ring, and tail support ring of the torso component rotate counterclockwise, causing the head scaling ring, tail scaling ring, and tail support ring of the tail component to radially shrink to a free state, thereby driving the folded metamaterial of the soft tube to shorten toward the head direction; S4. The driving motor is in a free state, so that the head support ring returns to a free state, and the drilling soft robot completes a cycle.

8. The drilling method of a drilling soft robot according to claim 7, characterized in that: The overall scaling range of the chiral metamaterial is λ∈[λ1,λ2], λ1<1,λ2>1; the Poisson's ratio of the concave quadrilateral folding structure of the soft tube is v∈[-1,1].

9. The drilling method of a drilling soft robot according to claim 8, characterized in that: In the initial stage S1, the cone angle formed by the head drilling ring is α0, the length of the soft tube is L0, the radius is r0, and the radius of the tail scaling ring, tail support ring, head scaling ring, and head support ring is r0; in the S2 drilling stage, the drilling ring of the head component is reduced in proportion to achieve a variable cone angle wedging into the soil. At this time, the cone angle is α, the radius of the tail support ring is enlarged to λ2r0, and the radii of the tail scaling ring and the head scaling ring are reduced to λ1r0, driving the radius of the soft tube of the torso component to be reduced to λ1r0, and the length is extended to ν[(1-λ1)+1]L0; in the S3 recovery stage, the head support ring is enlarged to λ2r0, the drilling ring is restored to the cone angle of α0, and the torso and tail components are restored to their initial size. At this time, the forward length of the soft robot is v(1-λ1)L0.

10. The drilling method of a drilling soft robot according to claim 8, characterized in that: When the folding angle θ of the unit cell structure of the concave quadrilateral folding is 135°, the Poisson's ratio v reaches a maximum value of 1, and the forward length of the drilling soft robot reaches the longest.

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