Sensing and driving module for pipeline soft robot

Abstract

The invention relates to a sensing and driving module for a pipeline soft robot, which comprises an axial actuator and a flexible strain sensor, and is characterized in that the axial actuator is cylindrical and is provided with three air cavities which are not communicated with each other, namely a first air cavity, a second air cavity and a third air cavity, and the first air cavity, the second air cavity and the third air cavity are communicated with each other; bending of the pipeline soft robot in various directions and angles is achieved by adjusting the pressure intensity of the first air cavity, the second air cavity and the third air cavity. Sensitive layers corresponding to a first air cavity, a second air cavity and a third air cavity are embedded in the axial actuator, each sensitive layer is located in a response area of the axial actuator, the response area is an area divided in the strain direction of the axial actuator, and the sensitive layers are flexible strain sensors. The sensing and driving module constructed by the invention can be effectively applied to the pipeline soft robot, and is more suitable for narrow and complex application scenes such as pipelines.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline soft robot design, and in particular to a perception and driving module for a pipeline soft robot. Background Art

[0002] With the development of soft robots, robots in many application scenarios have higher and higher degrees of freedom. The performance of pipeline robots in terms of flexibility and deformation is gradually enhanced, but this also makes pipeline soft robots face greater challenges in control and sensing.

[0003] At present, robots with various functions use flexible strain sensors for human-machine interaction or feedback control of robot motion, including soft robot grippers, transport robots, and therapeutic wearable robots. For example, Wang et al. proposed a new brittle stretchable conductive network strategy for stretchable strain sensors, which has high sensitivity in monitoring the performance of soft robot grippers. They observed the accurate anisotropic bending sensing performance of strain sensors by bending the robot gripper in different directions. A carbon-based composite strain sensor is used to control a mobile robot platform, in which the stretched and relaxed states of the sensor determine the direction of the robot's movement, i.e., forward or backward. Composite strain sensors based on glycerol / potassium chloride ionic liquids have also been shown to be useful for monitoring the movement of underwater robot arms, demonstrating their ability to be used in underwater applications.

[0004] Most of the research on pipeline soft robots chooses to add air pressure sensors to the control circuit, add cameras or distance measurement sensors to the robot head, etc., which cannot accurately control the pipeline soft robot through feedback. Because pipeline soft robots have high flexibility and good bending and extension properties. The standard modeling and control mode of traditional robotics based on rigid materials and structures is no longer applicable to soft robotics, and rigid sensors will destroy the overall soft elasticity and flexibility of soft robots. Therefore, flexible sensors are more suitable for pipeline soft robots.

[0005] However, most flexible strain sensors can only detect strain in a single direction, such as strain in the stretching direction. The directional information they provide for motion detection is still at the level of two-dimensional sensing, which limits the choice of application objects and is not conducive to feedback control of pipeline soft robots in directional perception.

[0006] In order to enhance the spatial perception ability of flexible sensors, Takei et al. designed 3D electronic whiskers by using asymmetric conductive materials on both sides, and the synergistic effect between their electrical and mechanical properties showed high sensitivity, but only included the perception of the direction perpendicular to the plane. Inspired by Venus flytraps and spiders, 3D strain sensors capable of sensing out-of-plane strains introduce hollow transition regions at the roots and change the stiffness of the substrate, concentrating local strains at the roots, and distinguishing the direction of applied force through four strain response regions. By integrating ultrasonic sensors and flexible triboelectric sensors, Shi et al. developed a soft robot perception system with remote object positioning and multimodal cognitive capabilities, which greatly improved the positioning ability of the manipulator when grasping objects. However, the use of the above perception system also has certain requirements for the application scenario, and is not suitable for pipes with small apertures or possible inner wall defects.

[0007] In summary, the existing structural design of pipeline soft robots is still imperfect, and the pipeline soft robots cannot be accurately controlled, which limits the application scope of pipeline soft robots. There is an urgent need to improve the structural design of pipeline soft robots. Summary of the invention

[0008] To this end, the technical problem to be solved by the present invention is to overcome the problem that the structural design of the pipeline soft robot in the prior art is still imperfect and the pipeline soft robot cannot be accurately controlled.

[0009] In order to solve the above technical problems, the present invention provides a perception and driving module for a pipeline soft robot, including an axial actuator and a flexible strain sensor, wherein:

[0010] The axial actuator is cylindrical and has three air cavities which are not connected to each other, namely, a first air cavity, a second air cavity and a third air cavity. By adjusting the pressure of the first air cavity, the second air cavity and the third air cavity, the pipeline soft robot can be bent in various directions and angles.

[0011] The axial actuator is embedded with sensitive layers corresponding to the first air cavity, the second air cavity and the third air cavity. Each of the sensitive layers is located in the response area of ​​the axial actuator. The response area is an area divided for distinguishing the strain direction of the axial actuator. The sensitive layer is a flexible strain sensor.

[0012] In one embodiment of the present invention, the sensitive layer is provided with a hollow structure, the hollow structure is used to enhance the sensitivity of the sensitive layer, and the hollow structure is circular or elliptical.

[0013] In one embodiment of the present invention, the sensing and driving module is axially stretched, and when the hollow structure is circular, the smaller the distance between two adjacent hollow structures, the higher the sensitivity of the sensitive layer.

[0014] In one embodiment of the present invention, the sensing and driving module is axially stretched, and when the hollow structure is an ellipse, and the major axis of the ellipse is located in the axial direction of the axial actuator and the minor axis is located in the radial direction of the axial actuator, if the minor axes of the two ellipses are the same, as the major axis increases and grows to a preset length, the sensitivity gradually increases. When the major axis increases to a preset length, it will decrease after increasing to a certain extent, because the increase in the total hollow area will reduce the influence of the minor axis on the sensitivity.

[0015] In one embodiment of the present invention, the sensing and driving module is axially stretched, and when the total area of ​​the circular hollow structure is the same as that of the elliptical hollow structure, the sensitivity of the elliptical hollow structure is higher than that of the circular hollow structure.

[0016] In one embodiment of the present invention, the sensitive layer is made of a conductive film, and when the conductive film is deformed, its own resistance changes, thereby changing the output electrical signal.

[0017] In one embodiment of the present invention, when the sensing and driving module is subjected to bending strain, the bending direction of the sensing and driving module is determined according to the sensitive layer with the smallest resistance among the sensitive layers corresponding to the three air cavities.

[0018] In one embodiment of the present invention, one end of the axial actuator is bent, and when the bending angle is 10 degrees to 65 degrees, the resistance of the sensitive layer corresponding to the air cavity increases as the bending angle increases; when the bending angle is 65 degrees to 90 degrees, the resistance of the sensitive layer corresponding to the air cavity increases as the bending angle increases;

[0019] Suppose the resistance growth rate when the bending angle is 10 degrees to 65 degrees is G1, and the resistance growth rate when the bending angle is 65 degrees to 90 degrees is G2, then G1>G2.

[0020] In one embodiment of the present invention, the first air cavity, the second air cavity and the third air cavity are of the same size and are fan-shaped in the cross section of the axial actuator, and each fan-shaped cavity is the same and has an angle of 120 degrees.

[0021] In one embodiment of the present invention, a fiber-reinforced wire or a spiral tube is wound around the surface of the axial actuator, and the fiber-reinforced wire or the spiral tube is used to limit the radial expansion of the axial actuator so as to enhance the axial extension.

[0022] The above technical solution of the present invention has the following advantages compared with the prior art:

[0023] The present invention designs a module with both the flexible strain sensor function and the axial actuator (deformation) function. In practical applications, it does not require an expensive and technically complex measurement interface, is more suitable for narrow and complex application scenarios such as pipelines, and has higher performance parameters. It realizes the precise sensing function of the pipeline soft robot without destroying the overall soft elasticity and flexibility of the pipeline soft robot.

[0024] The axial actuator of the pipeline soft robot of the present invention has the ability of autonomous bending and extension. Therefore, it is combined with the flexible strain sensor (i.e., the sensitive layer) into a module integrating perception and drive, so that the sensitive layer has more degrees of freedom without affecting the deformation ability of the pipeline soft robot, and the multi-dimensional perception ability of the module is also enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0026] FIG. 1( a ) is a top view of a sensing and driving module in an embodiment of the present invention;

[0027] FIG1( b ) is a structural design diagram of a sensitive layer in an embodiment of the present invention;

[0028] Figure 2 This is a preliminary design diagram of the sensing and driving module in an embodiment of the present invention;

[0029] FIG3( a ) is a stress distribution cloud diagram of the sensing and driving module under 50% strain in an embodiment of the present invention;

[0030] FIG3( b ) is a stress distribution cloud diagram of the sensing and driving module under 100% strain in an embodiment of the present invention;

[0031] FIG3( c ) is a stress distribution cloud diagram of the sensing and driving module under 150% strain in an embodiment of the present invention;

[0032] Figure 4 is a simulated displacement cloud diagram of the sensing and driving module bending toward the positive y-axis in an embodiment of the present invention;

[0033] Figure 5 is a simulated displacement cloud diagram of the sensing and driving module bending toward the negative y-axis in an embodiment of the present invention;

[0034] Figure 6 is a graph showing the relationship between the resistance and the bending angle of the sensing and driving module when it is bent toward the positive y-axis in an embodiment of the present invention;

[0035] Figure 7 is a graph showing the relationship between the resistance and the bending angle of the sensing and driving module when it is bent toward the negative y-axis in an embodiment of the present invention;

[0036] Figure 8 is a strain response region division diagram in an embodiment of the present invention;

[0037] Fig. 9 These are three offset situations in which the sensing and driving module is bent toward the direction of region A in the embodiment of the present invention;

[0038] Fig.10 is a diagram showing the response of the sensing and driving module in different bending directions according to an embodiment of the present invention;

[0039] Fig.11 3 is a diagram showing the response of the sensing and driving module at different bending angles according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0041] Embodiment 1

[0042] As shown in FIG. 1 , the present invention relates to a sensing and driving module for a pipeline soft robot, comprising an axial actuator 5 and a flexible strain sensor, wherein:

[0043] The axial actuator 5 is cylindrical and has three air cavities which are not connected to each other, namely, the first air cavity 1, the second air cavity 2 and the third air cavity 3. By adjusting the pressure of the first air cavity 1, the second air cavity 2 and the third air cavity 3, the pipeline soft robot can be bent in various directions and angles.

[0044] The axial actuator is embedded with sensitive layers 4 corresponding to the first air cavity 1, the second air cavity 2 and the third air cavity 3. Each of the sensitive layers 4 is located in the response area of ​​the axial actuator. The response area is an area divided for distinguishing the strain direction of the axial actuator. The sensitive layer 4 is a flexible strain sensor.

[0045] Furthermore, the sensitive layer 4 is provided with a hollow structure 6, and the hollow structure 6 is used to enhance the sensitivity of the sensitive layer 4, and the hollow structure 6 is circular or elliptical.

[0046] Furthermore, the sensing and driving module is axially stretched, and when the hollow structure 6 is circular, the smaller the distance between two adjacent hollow structures 6 is, the higher the sensitivity of the sensitive layer 4 is. It should be noted that the elliptical hollow structure 6 is not applicable to this situation.

[0047] Furthermore, the sensing and driving module is axially stretched, and when the hollow structure 6 is an ellipse, and the major axis of the ellipse is located in the axial direction of the axial actuator 5, and the minor axis is located in the radial direction of the axial actuator 5, if the minor axes of the two ellipses are the same, as the major axis increases and grows to a preset length, the sensitivity gradually increases. When the major axis exceeds the preset length, the sensitivity will decrease, because the increase in the total hollow area will reduce the influence of the major axis on the sensitivity.

[0048] Furthermore, the sensing and driving module is axially stretched. When the hollow structure 6 is elliptical and the total area of ​​the circular hollow structure 6 is the same as that of the elliptical hollow structure 6 , the sensitivity of the elliptical hollow structure 6 is higher than that of the circular hollow structure 6 .

[0049] Furthermore, the sensitive layer 4 uses a conductive film. When the conductive film is deformed, its own resistance changes, thereby changing the output electrical signal. The electrical signal will be transmitted to the controller outside the perception and driving module. The controller controls the pressure changes of the three air cavities according to the received electrical signal, thereby realizing the movement of the pipeline soft robot.

[0050] Further, when the sensing and driving module is bent and strained, the bending direction of the sensing and driving module is determined according to the sensitive layer 4 with the smallest resistance among the sensitive layers 4 corresponding to the three air cavities.

[0051] Furthermore, one end of the axial actuator 5 is bent, and when the bending angle is 10 degrees to 65 degrees, the resistance of the sensitive layer 4 corresponding to the air cavity increases with the increase of the bending angle; when the bending angle is 65 degrees to 90 degrees, the resistance of the sensitive layer 4 corresponding to the air cavity increases with the increase of the bending angle; assuming that the resistance growth rate when the bending angle is 10 degrees to 65 degrees is G1, and the resistance growth rate when the bending angle is 65 degrees to 90 degrees is G2, then G1>G2.

[0052] Furthermore, the first air cavity 1 , the second air cavity 2 and the third air cavity 3 are of the same size and are fan-shaped in the cross section of the axial actuator 5 , and each fan-shaped shape is the same and the angle is 120 degrees.

[0053] Furthermore, a fiber-reinforced wire or a spiral tube is wound around the surface of the axial actuator 5 , and the fiber-reinforced wire or the spiral tube is used to limit the radial expansion of the axial actuator 5 so as to enhance the axial extension.

[0054] The following is a detailed introduction to this embodiment:

[0055] In this embodiment, a conductive film is used as the sensitive layer 4 embedded in each response area of ​​the axial actuator 5 of the pipeline soft robot, and a module (i.e., a sensing and driving module) having both the function of a flexible strain sensor and a deformation function is designed. The conductive film can be made by combining the digital manufacturing technology of soft robots such as 3D printing with micro-machining technology. The conductive film is essentially a conductive network. Due to the microscopic changes in the conductive network, the conductive film will show a change in resistance when stretched or twisted. According to the relationship and resistance value between the resistances of each sensitive layer 4 of the module, the bending direction and bending angle of the axial actuator 5 can be inferred. In this way, the high integration of the flexible strain sensor and the pipeline soft robot is achieved, which is beneficial to the feedback control of the pipeline soft robot.

[0056] The axial actuator 5 of the pipeline soft robot as the module base has three air cavities. By adjusting the pressure of the three air cavities, bending in various directions and angles is completed. By winding the fiber-reinforced wire or spiral tube on the surface of the axial actuator 5 to limit its radial expansion and enhance the axial extension, the essence of the bending and extension of the axial actuator 5 is the axial extension or compression of the body material. As shown in Figure 1 (a), the three air cavities (the first air cavity 1, the second air cavity 2 and the third air cavity 3) all have corresponding sensitive layers 4, which can improve the deformability and sensitivity of the module to a certain extent. The flexible strain sensor (i.e., the sensitive layer 4) requires high sensitivity and excellent mechanical properties to capture subtle strains while maintaining high stretchability and conformability. Therefore, through the structural design of the sensitive layer 4 as shown in Figure 1 (b), the flexibility of the module can be effectively improved and multifunctional integration can be achieved. When improving the sensing performance, designing the sensitive layer 4 into a hollow structure 6 is conducive to local strain concentration, and the strain sensor with a hollow structure 6 shows higher sensitivity.

[0057] The sensitive layer 4, i.e., the conductive film, of this embodiment is essentially a conductive composite film in a porous shape. The conductive composite film is made of polydimethylsiloxane (PDMS), carbon black (CB) and deep eutectic solvent (DES), and is a very ideal material for a module with a flexible strain sensor function. Since it is a prior art, it will not be described in detail in this embodiment.

[0058] After the conductive film (i.e., the sensitive layer 4) of this embodiment is manufactured, a conductive network is formed inside it. When the conductive film is subjected to external pressure or tension, the conductive structure of the conductive film changes, and the resistance of the conductive film changes, thereby changing the output electrical signal. According to the tunneling effect, the electrons inside the sensitive layer 4 can cross the non-conductive barrier to form a conductive path when there is no contact between the nanomaterials. The tunneling resistance of two electrons between adjacent nanomaterials can be approximately determined by the Simmons equation:

[0059]

[0060] In the above formula, V / v is the potential difference, A / mm 2 is the cross-sectional area of ​​the tunnel, J / (A / ㎡) is the tunnel current density, h / (J·s) is the Planck constant, and d N / mm is the distance between adjacent nanomaterials, e / c is the unit charge, m / kg is the mass of an electron, and γ / mm is the height of the polymer barrier.

[0061] This embodiment uses COMSOL multi-physics finite element simulation software to conduct experiments. For the convenience of simulation, the details of the electrode and the air cavity are simplified. The Mooney-Rivlin two-parameter hyperelastic material model is used. The material parameters are: C 10 =5.7337×10 5 Pa, C 01 =-4918.7Pa, bulk modulus is 240MPa, density is 1040kg / m 3 , the material conductivity of the sensitive layer 4 of the module is 0.01s / m, and the Figure 2 The module shown, where the parameters, r 1 is the radius of the cylindrical axial actuator 5, r 2 is the radius of the fan-shaped air cavity, r 3 is the maximum distance between the sensitive layer 4 and the central axis of the axial actuator 5, r 4 is the minimum distance between the sensitive layer 4 and the central axis of the axial actuator 5, h 1 is the height of the cylindrical axial actuator 5, h 2 is the height of the sensitive layer 4 in the axial direction, a is the radius of the circular hollow structure 6, d is the distance between adjacent circular hollow structures 6, and r 1 =15mm, r 2 =12mm, r 3 =13.75mm, r 4 =13.25mm,h 1 =70mm,h 2 =60mm, a=5mm, d=20mm. The grid is divided by solid mechanics and current physical field control, and the current terminal and ground are respectively set at the boundary sections of the sensitive layer 4 at both ends of the z-axis direction. The voltage is set to 1V, and the displacement of the module in the x-axis and y-axis directions is specified to be 0, and the displacement in the z-axis direction is half the strain. After the module is stretched in the z-axis direction, the sensitivity of the module with different parameter hollow structures 6 under axial strain is studied.

[0062] In this embodiment, the sensitivity is the change in the output response of the sensor to a unit change in the input. According to the sensitivity of the sensitive layer 4 of the GF evaluation module, the GF is defined as the ratio of the relative change in the output signal to the applied strain. The GF of the module can be calculated as follows:

[0063]

[0064] In the above formula, ε represents the applied strain, R / Ω represents the resistance, and ΔR represents the resistance change. It is not difficult to find that the higher the GF value, the more sensitive the module is to the applied strain.

[0065] In this embodiment, finite element simulation is performed on modules with different structures to analyze the change in resistance before and after axial strain occurs, and the relevant parameters and the response results of the corresponding modules under strain are specifically shown in Table 1.

[0066] By analyzing the data in Table 1, it is found that when the hollow structure 6 is circular, the larger the distance between the centers of the two hollow structures 6 is under the same radius and number, the lower the sensitivity of the sensitive layer 4. By comparing No. 3, No. 4 and No. 5, and No. 3, No. 4 and No. 6, it is found that when the radius and number of the hollow structures 6 are different but the total area of ​​the hollow structures 6 is the same, the larger the distance between the two hollow structures 6 is, the lower the sensitivity is. By comparing No. 1, No. 2, No. 3, No. 4 and No. 7, it is found that when the radius of the hollow structures 6 is the same, the sensitivity decreases when the number of hollow structures 6 is increased and the distance between the two hollow structures 6 is reduced. Combined with the above description, the distance has little effect on the sensitivity, and the shape and area of ​​the hollow structure 6 have a greater effect on the sensitivity.

[0067] Table 1 Response data of sensitive layer with circular hole structure of different parameters

[0068]

[0069] The stress distribution of the module under different strains was analyzed by finite element simulation. The simulation results show that the sensitive layer 4 of the module shows stress concentration under different strains. Figures 3(a), 3(b) and 3(c) show the stress distribution cloud diagrams of the module under different strains. It can be seen that the stress is mainly concentrated on the axial edge of the circular hole of the sensitive layer 4, while the stress in other parts shows a more uniform distribution under strain.

[0070] In order to increase the influence of strain on the sensitive layer and thus enhance the sensing performance of the module, the axial edge ratio of the hollow structure of the sensitive layer can be increased, that is, the shape of the circular hole is changed to an ellipse. After changing the relevant parameters, the finite element simulation is performed again to obtain the data shown in Table 2.

[0071] Comparing No. 5 and No. 6 in Table 1 with No. 8 in Table 2, and comparing No. 7 in Table 1 with No. 9 in Table 2, it is found that: when the total area is the same, the hollow structure 6 is elliptical and has higher sensitivity. Analyzing the data in Table 2, comparing No. 8 with No. 10, No. 11, and No. 9 with No. 12: when c is the same, as b increases, the sensitivity increases slowly. At the same time, the increase in the total area of ​​the hollow structure 6 also reduces the effect of b on the sensitivity, so the sensitivity of No. 11 is reduced. Comparing No. 8, No. 10, No. 13, and No. 14, it is found that: when the shape is the same (here refers to the elliptical hollow structure 6), appropriately increasing the number of radially arranged ellipses is conducive to increasing the sensitivity, but in general, the number of ellipses has little effect on the sensitivity, so this embodiment does not use the radial arrangement when actually designing the hollow structure 6.

[0072] Table 2 Response data of sensitive layer of elliptical hollow structure with different parameters

[0073]

[0074] In summary, after analysis, the structural parameter No. 10 in Table 2 can be selected when manufacturing the module in this embodiment.

[0075] When the module is subjected to bending strain, the three sensitive layers 4 are subjected to different degrees of axial strain, resulting in changes in the resistance of the three sensitive layers 4. Through finite element simulation analysis, forces are applied to the module in different directions. In order to quantify the bending angle, the two ends of the axial actuator 5 are fixed and the center of the axial actuator 5 is used as the force point to bend the module. The displacement direction of the center of the module is regarded as the bending direction, such as Figure 4 This is the finite element simulation displacement cloud diagram of the module bending toward the positive y-axis. Figure 5 This is the finite element simulation displacement cloud diagram of the module bending toward the negative y-axis.

[0076] The center point is connected to the center points of both ends of the axial actuator 5 respectively, and the angle formed is regarded as the bending angle, and the change of the resistance of each sensitive layer 4 and the bending angle of the module is analyzed.

[0077] When the direction of the force applied to the module is the positive y-axis direction (here it is assumed that Figure 8 The first sensitive layer 41 is subjected to a positive force), and the relationship between the resistance of the three sensitive layers 4 and the bending angle of the module is as follows: Figure 6As shown in the figure, the resistance of the three sensitive layers 4 increases exponentially with the increase of the bending angle. For the convenience of analysis, the three sensitive layers 4 are refined into the first sensitive layer 41, the second sensitive layer 42 and the third sensitive layer 43. The resistance of the second sensitive layer 42 and the third sensitive layer 43 is the same and greater than the resistance of the first sensitive layer 41. When the bending angle increases, the difference between them increases slowly. The sensitive layer 4 is deformed to different degrees due to the deformation of the axial actuator 5, resulting in a change in resistance. The greater the bending angle, the greater the difference between the different deformation degrees, showing a greater difference between the resistances.

[0078] When the force applied to the module is in the negative y-axis direction, the force is applied between the sensitive layer 2 and the sensitive layer 3 (here it is assumed that Figure 8 The relationship between the resistance of the three sensitive layers 4 and the bending angle of the module is as follows: Figure 7 As shown in the figure, the resistances of the three sensitive layers 4 increase exponentially with the increase of the bending angle, the resistances of the second sensitive layer 42 and the third sensitive layer 43 are the same and smaller than the resistance of the first sensitive layer 41, and the difference between them increases slowly as the bending angle increases. The relationship between the resistances of the sensitive layers 4 and the resistance and the bending angle are consistent with the above rules, and the bending direction of the module can be determined according to the sensitive layer 4 with smaller resistance.

[0079] In summary, according to the relationship and resistance value between the resistances of each sensitive layer 4 of the module, the bending direction and bending angle of the axial actuator 5 can be inferred. In order to distinguish the bending direction more accurately and quickly, the following is established according to the direction of the sensitive layer 4: Figure 8 The three large strain response areas shown are A, B, and C. Fig.10 In the figure, R1 represents the resistance of the first sensitive layer 41, R2 represents the resistance of the second sensitive layer 42, R3 represents the resistance of the third sensitive layer 43, area A represents bending in the direction of the first sensitive layer 41, area B represents bending in the direction of the second sensitive layer 42, and area C represents bending in the direction of the third sensitive layer 43. Each large area in the figure is subdivided into three small areas according to the biased direction. Area Aa represents bending in the direction of the first sensitive layer 41 without other deviations, area Ab represents bending in the direction of the first sensitive layer 41 but slightly deviates in the direction close to the second sensitive layer 42, and area Ac represents bending in the direction of the first sensitive layer 41 but slightly deviates in the direction close to the third sensitive layer 43. Fig. 9 The following are three cases where the module is bent toward region A. Similarly, the first character of the region name indicates the approximate bending direction, the second character indicates the offset direction, and the small region represents a more precise bending direction.

[0080] Therefore, the module can feedback the bending direction and bending angle of the axial actuator 5 in multiple dimensions without affecting its own degrees of freedom. The response is as follows: Fig.10 and Fig.11 As shown, one end of the axial actuator 5 is bent. When the bending angle is 10-65 degrees, the resistance of the sensitive layer 4 corresponding to the air cavity increases with the bending angle (the resistance increases faster at this time); when the bending angle is 65-90 degrees, the resistance of the sensitive layer 4 corresponding to the air cavity increases with the bending angle (the resistance increases slowly at this time). Since the resistance change corresponding to 0-10 degrees is not obvious, this embodiment does not perform statistics.

[0081] The present invention uses a conductive film as a sensitive layer embedded in each response area of ​​the axial actuator 5 of the pipeline soft robot, and designs a module with both flexible strain sensor function and deformation function. In practical applications, it does not require an expensive and technically complex measurement interface, and achieves high integration of the flexible strain sensor and the pipeline soft robot, which is beneficial to the feedback control of the pipeline soft robot. The present invention enables the sensitive layer 4 to have more degrees of freedom without affecting the deformation ability of the pipeline soft robot, and the multi-dimensional perception ability of the module is also enhanced.

[0082] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0083] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A perception and driving module for a pipeline soft robot, characterized in that: It comprises an axial actuator (5) and a flexible strain sensor, wherein: The axial actuator (5) is cylindrical and has three air cavities which are not connected to each other, namely a first air cavity (1), a second air cavity (2) and a third air cavity (3). By adjusting the pressure of the first air cavity (1), the second air cavity (2) and the third air cavity (3), the pipeline soft robot can be bent in various directions and angles. The axial actuator (5) is embedded with sensitive layers (4) corresponding to the first air cavity (1), the second air cavity (2) and the third air cavity (3); each of the sensitive layers (4) is located in a response area of ​​the axial actuator (5); the response area is an area divided for distinguishing the strain direction of the axial actuator; and the sensitive layer (4) is a flexible strain sensor.

2. The sensing and driving module for a pipeline soft robot according to claim 1, characterized in that: The sensitive layer (4) is provided with a hollow structure (6), and the hollow structure (6) is used to enhance the sensitivity of the sensitive layer (4). The hollow structure (6) is circular or elliptical.

3. The sensing and driving module for a pipeline soft robot according to claim 2, characterized in that: The sensing and driving module is axially stretched. When the hollow structure (6) is circular, the smaller the distance between two adjacent hollow structures (6), the higher the sensitivity of the sensitive layer (4).

4. The sensing and driving module for a pipeline soft robot according to claim 3, characterized in that: The sensing and driving module is axially stretched. When the hollow structure (6) is elliptical, and the major axis of the ellipse is located in the axial direction of the axial actuator (5), and the minor axis is located in the radial direction of the axial actuator (5), if the minor axes of the two ellipses are the same, the sensitivity gradually increases as the major axis increases and grows to a preset length.

5. The sensing and driving module for a pipeline soft robot according to claim 3, characterized in that: The sensing and driving module is axially stretched. When the total area of ​​the circular hollow structure (6) and the elliptical hollow structure (6) is the same, the sensitivity of the elliptical hollow structure (6) is higher than that of the circular hollow structure (6).

6. The sensing and driving module for a pipeline soft robot according to claim 1, characterized in that: The sensitive layer (4) is made of a conductive film, and when the conductive film is deformed, its own resistance changes, thereby changing the output electrical signal.

7. The sensing and driving module for a pipeline soft robot according to claim 6, characterized in that: When the sensing and driving module is subjected to bending strain, the bending direction of the sensing and driving module is determined according to the sensitive layer (4) with the smallest resistance among the sensitive layers (4) corresponding to the three air cavities.

8. The sensing and driving module for a pipeline soft robot according to claim 6, characterized in that: One end of the axial actuator (5) is bent, and when the bending angle is 10 degrees to 65 degrees, the resistance of the sensitive layer (4) corresponding to the air cavity increases as the bending angle increases; when the bending angle is 65 degrees to 90 degrees, the resistance of the sensitive layer (4) corresponding to the air cavity increases as the bending angle increases; assuming that the resistance growth rate when the bending angle is 10 degrees to 65 degrees is G1, and the resistance growth rate when the bending angle is 65 degrees to 90 degrees is G2, then G1>G2.

9. The sensing and driving module for a pipeline soft robot according to claim 1, characterized in that: The first air cavity (1), the second air cavity (2) and the third air cavity (3) are of the same size and are fan-shaped in the cross section of the axial actuator (5), and each fan-shaped cavity has the same shape and an angle of 120 degrees.

10. The sensing and driving module for a pipeline soft robot according to claim 1, characterized in that: The surface of the axial actuator (5) is wound with a fiber-reinforced wire or a spiral tube, and the fiber-reinforced wire or the spiral tube is used to limit the radial expansion of the axial actuator (5) so as to enhance the axial extension.

Images