A soft crawling robot and a control method thereof

Abstract

The application provides a soft crawling robot machine control method, the robot comprises a front support module, a rear support module, a strip-shaped driver, a first telescopic mechanism and a first linear spring, the front support module and the rear support module are both provided with friction feet below, the strip-shaped driver comprises two upper and lower parts, is connected with the front support module and the rear support module, and forms a cavity with the front support module and the rear support module, the telescopic mechanism and the linear spring are arranged between the cavity formed by the front support module, the rear support module and the strip-shaped driver, the first telescopic mechanism passes through the first linear spring, the strip-shaped driver is in a balanced state with the compressed first linear spring, the front support module and the rear support module are in a concave shape, and the concave-shaped object table of the rear support module is provided with a left steering shaft and a right steering shaft. The soft crawling robot of the application has a simple structure, uses a dielectric elastomer as a driver, and has a low cost.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, and in particular relates to a soft crawling robot and its control method. Background Technology

[0002] Currently, mobile robots with rigid structures have been widely used in industrial, military, and rescue fields. However, traditional rigid robots have complex structures, cannot adapt to unstructured environments, and may cause harm to themselves and their surroundings, which greatly limits their application in unstructured environments, human-computer interaction, and intelligent bionics.

[0003] Soft robots can actively generate or passively withstand large continuous deformations, possessing a high degree of freedom of movement and better environmental adaptability. For example, soft robots can move in narrow gaps or spaces with restricted movement; they can withstand impacts, heavy pressure, and drops without structural or functional damage; and they do not damage fragile objects when used for grasping or manipulation.

[0004] Commonly used actuators include shape memory alloys, liquid crystal elastomers, pneumatic actuators, magnetic response actuators, and dielectric elastomer actuators. The fast response of dielectric elastomer actuators is beneficial for increasing the flexibility of soft robots, enabling rapid switching and control of different motion modes or functions. Therefore, most soft robots use dielectric elastomers as flexible actuators.

[0005] Soft crawling robots are typically made of flexible and stretchable materials. However, this flexibility reduces their speed and load-bearing capacity. When dielectric elastomers are used as the actuating material, a rigid frame is often required to support the elastomer membrane, further reducing the robot's flexibility. Currently, most soft crawling robots lack load-bearing capacity, and some lack steering ability and high crawling speed. Summary of the Invention

[0006] In view of this, the present invention aims to overcome the shortcomings of the above-mentioned problems in the prior art, and to develop a soft crawling robot with more precise control and high response efficiency based on dielectric elastomer materials. Furthermore, it designs appropriate turning methods to improve the crawling speed and load capacity of the soft robot, enabling it to quickly reach the designated position under a certain load, thus meeting the needs of practical applications.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] The first aspect of the present invention provides a soft crawling robot, including a front support module, a rear support module, a strip actuator, a first telescopic mechanism, and a first linear spring. Both the front and rear support modules have friction feet at their lower ends. The strip actuator comprises two components, one above the other, connecting the front and rear support modules and forming a cavity with them. The first telescopic mechanism and the first linear spring are disposed between the cavity formed by the front and rear support modules and the strip actuator. The first telescopic mechanism passes through the first linear spring, and the strip actuator is in a balanced state with the compressed first linear spring. The front and rear support modules are concave in shape, and the concave platform of the rear support module has a left steering shaft and a right steering shaft.

[0009] Furthermore, the friction foot is at a 45-degree angle to the ground.

[0010] Furthermore, the strip driver is attached to the upper and lower sides of the front support module and the rear support module with double-sided tape, and includes a first dielectric elastomer, a first conductive rubber and a first copper wire. The first conductive rubber is attached to both sides of the first dielectric elastomer, and the first conductive rubber on both sides is connected to the high voltage amplifier through the first copper wire. The signal generator generates an AC signal to power the high voltage amplifier to supply power to the strip driver.

[0011] Furthermore, the left and right steering shafts are cylindrical and each includes a cylindrical actuator, a capillary tube, a bearing, a bearing sleeve, and a silicone sheet. The inner diameter of the bearing is larger than the outer diameter of the capillary tube and is directly fitted onto the capillary tube. The bearing sleeve is fitted onto the outer diameter of the bearing, and a circular silicone sheet is connected to the lower end of the bearing sleeve parallel to the ground using double-sided tape.

[0012] Furthermore, the cylindrical actuator includes a second dielectric elastomer, a second conductive rubber, a second copper wire, an upper end cover, a second telescopic mechanism, a second linear spring, and a lower end cover. Second conductive rubber is attached to both sides of the second dielectric elastomer, and the second copper wire is led out and fixed to the upper and lower end covers with double-sided tape. A cylindrical hole is provided in the middle of the upper and lower end covers to fix capillary tubes of different diameters to the upper and lower end covers respectively, forming the second telescopic mechanism. The second linear spring is sleeved on the capillary tube of the second telescopic mechanism. The outer diameter of the capillary tube at the lower end of the steering shaft is smaller than the inner diameter of the capillary tube at the lower end cover of the cylindrical actuator. The capillary tube at the lower end of the steering shaft is directly inserted into the capillary tube of the second telescopic mechanism of the cylindrical actuator.

[0013] Furthermore, the first telescopic mechanism includes two capillaries of the same length.

[0014] Furthermore, the front support module and the rear support module are made of PLA material and printed by a 3D printer.

[0015] A second aspect of the present invention provides a control method for a soft crawling robot, comprising:

[0016] (1) Straight-through phase:

[0017] When the upper and lower strip actuators are powered on, the strip actuators extend along the direction of the first linear spring force, the robot's front support module moves forward, and the rear support module remains stationary;

[0018] When the strip actuator is de-energized, the first linear spring is compressed, the robot body shortens, the robot's rear support module moves forward, and the front support module remains stationary.

[0019] A sine wave is continuously supplied to the strip actuator, with a voltage set to a certain amplitude and period, and the soft crawling robot continues to crawl forward.

[0020] (2) Turning around:

[0021] Based on the robot's straight-line movement, when DC power is applied to the left steering axis of the crawling robot, the silicone pad at the end of the left steering axis contacts the ground. Continuous power supply anchors the silicone pad of the left steering axis to the ground, and the robot turns left and around the left steering axis through the bearing.

[0022] Based on the robot's straight-line movement, when DC power is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis contacts the ground. Continuous power supply anchors the silicone pad at the end of the right steering axis to the ground, and the robot turns right and turns around the right steering axis through the bearing.

[0023] (3) Turning phase:

[0024] Based on the robot's straight-line movement, when a sinusoidal voltage is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis intermittently contacts the ground. When the right steering axis extends, the silicone pad is anchored to the ground, and the robot rotates to the right around the right steering axis through the bearing. When sinusoidal voltages of different frequencies are applied to the steering axis, the robot's turning radius changes. When the right steering axis shortens, the silicone pad detaches from the ground, and the robot moves straight.

[0025] Compared with existing technologies, the soft crawling robot and its control method described in this invention have the following advantages:

[0026] The soft crawling robot designed in this invention has a simple structure, uses a dielectric elastomer as an actuator, has low cost, and has a small overall size and mass.

[0027] The rigid-flexible coupling structure of the robot of the present invention increases the rigidity of the soft robot, enabling it to crawl effectively under a load exceeding 20 times its own mass, thus improving the problem of soft robots having no load capacity or a small load capacity.

[0028] The crawling robot of this invention has the ability to turn. The designed soft robot can not only turn left and right, but also adjust the turning radius of the crawling robot when turning, which can help the robot to turn in specific environments, improve the robot's crawling speed and environmental adaptability.

[0029] The robot of this invention can turn around on the spot while anchored, improving the ability of crawling robots to move in narrow spaces.

[0030] The robot steering mechanism of the present invention is installed inside the rear platform of the robot, making the robot structure simple and compact, and the steering effect obvious. Attached Figure Description

[0031] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 This is a parts assembly diagram of the soft crawling robot of the present invention;

[0033] Figure 2 This is a side view of the soft crawling robot of the present invention;

[0034] Figure 3 This is a rear view of the soft crawling robot of the present invention;

[0035] Figure 4 This is a schematic diagram of the strip-shaped driver structure of the present invention;

[0036] Figure 5 This is a schematic diagram of the columnar actuator structure of the present invention;

[0037] Figure 6 This is a cross-sectional view and a front view of the steering shaft of the present invention;

[0038] Figure 7 This is an assembly diagram of the columnar actuator parts of the present invention;

[0039] Figure 8 This is a three-dimensional schematic diagram of the steering shaft of the present invention.

[0040] Explanation of reference numerals in the attached figures

[0041] 1-Front support module; 2-Front friction foot; 3-Strip actuator; 4-First telescopic mechanism; 5-First linear spring; 6-Rear support module; 7-Rear friction foot; 8-Left steering shaft; 9-Right steering shaft; 10-First dielectric elastomer; 11-First conductive rubber; 12-First copper wire; 13-Columnar actuator; 14-Capillary tube; 15-Bearing; 16-Bearing sleeve; 17-Silicone sheet; 18-Upper end cover; 19-Lower end cover; 20-Second dielectric elastomer; 21-Second conductive rubber; 22-Second linear spring; 23-Second telescopic mechanism; 24-Double-sided tape; 25-Second copper wire. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] like Figure 1-3As shown, this invention provides a quadrupedal soft crawling robot, comprising a stretchable strip-shaped actuator 3, a rigid retractable body, a linear spring, four rigid legs, and two retractable columnar actuators 13, with the columnar actuators 13 mounted on the robot's tail. The quadrupedal soft crawling robot can move forward, turn left, turn right, and turn around on the spot. The robot's four rigid legs are mounted at a 45-degree angle to the ground, providing anisotropic friction. The front and rear pairs of friction legs are mounted parallel to each other.

[0047] This invention selects a dielectric elastomer actuator (DEA) as the actuator for a soft crawling robot. The DEA consists of a middle dielectric layer and two electrode layers on both sides. When a voltage is applied, Maxwell stress is generated, causing the dielectric layer to contract along the direction of the electric field and expand perpendicular to the direction of the electric field. After the voltage is removed, the film recovers its deformation.

[0048] like Figure 4 As shown, the strip-shaped actuator 3 of the soft crawling robot is composed of a first dielectric elastomer 10 film with first conductive rubber 11 attached to both sides. The first conductive rubber 11 on both sides is connected to a high-voltage amplifier through a first copper wire 12. An AC signal is generated by a signal generator and sent to the high-voltage amplifier to power the strip-shaped actuator 3.

[0049] like Figure 5 As shown, firstly, second conductive rubber 21 is attached to both sides of the second dielectric elastomer 20, and then led out by the second copper wire 25 and fixed to the upper end cover 18 and the lower end cover 19 by double-sided tape 24. Together with the second linear spring 22, it forms a cylindrical actuator 13 that can extend and retract with a single degree of freedom.

[0050] Specifically, soft crawling robots mainly include the following modules:

[0051] A hole is drilled in the lower side of the front support module 1 to install the front friction foot 2 of the crawling robot. During installation, the front friction foot 2 is at a 45-degree angle to the ground. A strip-shaped actuator 3 is attached to the upper and lower sides of the support module using double-sided tape. A telescopic rod is drilled in the center of the front and rear support modules to install a single-degree-of-freedom first telescopic mechanism 4. The first telescopic mechanism 4 passes through a first linear spring 5, and the strip-shaped actuator 3 and the compressed first linear spring 5 are in a balanced state. A hole is drilled in the lower side of the rear support module 6 to install the rear friction foot 7 of the crawling robot. During installation, the rear friction foot 7 is at a 45-degree angle to the ground and parallel to the front friction foot 2.

[0052] A through hole is drilled at the platform of the rear support module 6 to install the left steering shaft 7 and the right steering shaft 8. (Example) Figure 6 , 8 As shown, the steering shaft is cylindrical and can extend and retract perpendicular to the ground. Both the left steering shaft 7 and the right steering shaft 8 consist of a cylindrical actuator 13, a capillary tube 14, a bearing 15, a bearing sleeve 16, and a silicone sheet 17. The assembly diagram of the cylindrical actuator 13 is shown below. Figure 7As shown. The height of the steering shaft in balanced state is 23mm. The second dielectric elastomer 20 is connected to the high-voltage amplifier through the second copper wire to obtain high voltage. The signal generator adjusts the amplitude, waveform, and frequency of the input voltage.

[0053] The soft crawling robot weighs 10g, is 65mm long, and 34mm wide. The strip-shaped actuator 3 is 40mm long, 30mm wide, and 35µm thick. The columnar actuator has a circumference of 21.5mm, a height of 18mm, and a thickness of 35µm.

[0054] The robot of this invention has a steering mechanism installed inside the rear platform, which makes the robot structure simple and compact, with obvious steering effect and does not hinder the movement of the main body; the robot's rigidity is sufficient to improve the robot's load capacity; the robot is simple to manufacture, and some structures are printed using PLA material, so the robot is small in size and light in weight.

[0055] Specifically, the front support module 1 is 3D printed using PLA material. The dimensions of the front support module 1 (length * width * height) are 34 * 14 * 20 mm. The front support module 1 includes a stage, cylindrical friction foot mounting holes, and cylindrical capillary mounting holes. The dimensions of the upper and lower stages are 34 * 9 * 2 mm. The cylindrical friction foot mounting holes are 1.1 mm in diameter and 2 mm deep, with their centers located 1 mm to the left and 10 mm to the rear. The cylindrical capillary mounting holes are 3.6 mm in diameter and 4 mm deep, located at the center of the rear rectangle of the front support module 1.

[0056] The rear support module 6 is 3D printed using PLA material. Its dimensions (length * width * height) are 34 * 14 * 20 mm. The rear support module 6 includes a stage, cylindrical friction foot mounting holes, cylindrical capillary mounting holes, left and right steering shaft mounting holes, and cylindrical actuator telescopic constraint holes. The upper and lower stages measure 34 * 9 * 2 mm. The cylindrical friction foot mounting holes are 1.1 mm in diameter and 2 mm deep, located 1 mm to the left and 10 mm to the rear. The cylindrical capillary mounting holes are 2.4 mm in diameter and 4 mm deep, located at the center of the front rectangle. The left and right steering shaft mounting holes are 6.6 mm in diameter and 2 mm deep, located on the left and right sides of the stage, with their centers 6 mm from the edges of the stage. The cylindrical actuator telescopic constraint holes are 3.8 mm in diameter and 2 mm deep, with their centers aligned with the centers of the two upper holes.

[0057] The robot's friction feet are made using positioning pins. The overall height of the friction feet is 7.5mm, and the vertical length is 3.5mm. The positioning pins are bent at a 135-degree angle and are installed in the friction foot mounting holes on the front and rear support modules using quick-drying adhesive. After the robot's friction feet are installed, the robot is 5.5mm off the ground.

[0058] The strip-shaped driver 3 consists of a dielectric layer and conductive layers on the top and bottom sides. The dielectric layer measures 40*30*0.035mm, and the conductive layer measures 30*25*0.020mm. A 5mm non-deformable area is reserved at both ends of the dielectric layer for fixing it to the front and rear support modules. A 2.5mm non-deformable area is reserved on both sides of the dielectric layer to prevent short circuits caused by the conductive layers being too close together.

[0059] The single-degree-of-freedom first telescopic mechanism 4 consists of two capillary tubes, each 30 mm long. The capillary tubes have an outer diameter of 3.8 mm, a wall thickness of 0.2 mm, and a height of 30 mm. The first capillary tube has an outer diameter of 2.4 mm, a wall thickness of 2 mm, and a depth of 30 mm. Using quick-drying adhesive, the two capillary tubes are installed on the columnar actuator mounting holes on the upper sides of the front and rear support modules. The robot can then extend and retract along the axis of the capillary tubes. The first linear spring 5, through which the first telescopic mechanism 4 passes, has an outer diameter of 5 mm, a wire diameter of 0.4 mm, and a length of 50 mm.

[0060] The columnar actuator 13 consists of an upper end cover 18, a second telescopic mechanism 23, a second linear spring 22, and a lower end cover 19. A cylindrical hole is provided between the upper and lower end covers. Capillary tubes of different diameters are fixed to the upper and lower end covers using quick-drying adhesive, forming the second telescopic mechanism 23. The second linear spring 22 is fitted onto the capillary tube of the second telescopic mechanism 23. The outer diameter of the capillary tube at the lower end of the steering shaft is smaller than the inner diameter of the capillary tube at the lower end cover of the columnar actuator. Therefore, the capillary tube at the lower end of the steering shaft is directly inserted into the capillary tube of the second telescopic mechanism of the columnar actuator and fixed using quick-drying adhesive. The inner diameter of the bearing 15 is larger than the outer diameter of the capillary tube, and it is directly fitted onto the capillary tube and connected using quick-drying adhesive. To increase the contact area between the end of the steering shaft and the ground, and to increase friction, a bearing sleeve 16, 3D printed, is fitted onto the outer diameter of the bearing 15 and fixed using quick-drying adhesive. A circular silicone sheet 17 is connected to the lower end of the bearing sleeve 16 parallel to the ground using double-sided tape 24 to increase the friction between the steering shaft and the ground. The upper and lower end caps are 3D printed using PLA material. The upper end cap base has a diameter of 6.5mm and a height of 1mm. It is installed in the steering shaft mounting hole of the rear support module and secured with quick-drying adhesive. A cylindrical groove with a diameter of 2.8mm and a depth of 1mm is located in the center for mounting the capillary tube. A hollow cylinder, concentric with the base, serves as a spring mounting slot on the upper surface of the base, with dimensions of 4.2mm inner diameter, 5.6mm outer diameter, and 2mm depth. The lower end cap base has a diameter of 6.5mm and a height of 1mm. A cylindrical groove with a diameter of 2mm and a depth of 1.5mm is located in the center for mounting the capillary tube. A hollow cylinder, concentric with the base, serves as a spring mounting slot on the upper surface of the base, with dimensions of 4.2mm inner diameter, 5.6mm outer diameter, and 2mm depth. A second linear spring 22, with an outer diameter of 4mm, a wire diameter of 0.4mm, and a length of 35mm, is fitted onto a second telescopic mechanism 23. The second telescopic mechanism 23 consists of a capillary tube with an outer diameter of 2.8mm, a wall thickness of 0.2mm, and a height of 5mm, and another capillary tube with an outer diameter of 2mm, a wall thickness of 0.2mm, and a height of 8mm. A 21.5*17mm dielectric layer and two 17*13mm conductive layers form an actuator, which is attached to the outer side of the hollow cylinder at the upper and lower end caps to form a cylindrical actuator 1. Therefore, when the cylindrical actuator is energized, the steering shaft can extend and retract in a direction perpendicular to the ground, serving an anchoring function.

[0061] The control method of the soft crawling robot of the present invention is as follows:

[0062] (1) Straight-through phase

[0063] The key to the straight-line movement of soft crawling robots lies in the fact that the robot has anisotropic friction feet and periodic stretching and contraction forces provided by dielectric elastomer actuators and springs.

[0064] Step 1: Power on the upper and lower strip actuators. The strip actuators extend along the direction of the first linear spring force. Since the robot body is rigid, the spring force of the first linear spring acts on the rigid friction feet. At this time, both the front and rear pairs of friction feet are subjected to an outward force provided by the spring. For the front support module, the force exerted by the ground on the friction feet is backward, and for the rear support module, the force exerted by the ground on the friction feet is forward. Due to the anisotropy of the friction feet (the friction in the positive direction is less than the friction in the negative direction), the robot's front support module moves forward, while the rear support module remains stationary.

[0065] Step 2: When the strip actuator is de-energized, the first linear spring will be compressed due to the tension of the membrane, and the robot body will shorten. At this time, both the front and rear pairs of friction groups are subjected to the inward force provided by the spring. Due to the anisotropy of the friction feet, the rear support module of the robot moves forward, while the front support module remains stationary. Therefore, in one cycle of energizing the actuator, the robot will move forward a certain distance.

[0066] Step 3: Continuously supply a sine wave to the strip actuator, setting a specific amplitude and period for the voltage. The soft crawling robot will then continuously crawl forward.

[0067] (2) Turning around

[0068] Step 1: With the robot moving in a straight line, when DC power is applied to the left steering axis of the crawling robot, the silicone pad at the end of the left steering axis contacts the ground. Continuous power supply anchors the silicone pad to the ground. At this time, the right front and rear friction feet of the crawling robot are effectively crawling, while the left front and rear friction feet, anchored to the left steering axis, show no tendency to crawl. Because the main body of the crawling robot is a rigid structure, the robot will turn left and turn around by passing the bearing around the left steering axis.

[0069] Step Two: With the robot moving in a straight line, when DC power is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis contacts the ground. Continuous power supply anchors the silicone pad to the ground. At this time, the left front and rear friction feet of the crawling robot are effectively crawling, while the right front and rear friction feet, anchored to the left steering axis, show no tendency to crawl. Because the main body of the crawling robot is a rigid structure, the robot will turn right and turn around via the bearing around the right steering axis.

[0070] (3) Turning phase

[0071] Step 1: With the robot moving in a straight line, when a sinusoidal voltage is applied to the left steering axis of the crawling robot, the silicone pad at the end of the left steering axis periodically contacts the ground. When the left steering axis extends, the silicone pad anchors to the ground, and the robot rotates to the left around the left steering axis via the bearing. When sinusoidal voltages of different frequencies are applied to the steering axis, the robot's turning radius also changes. When the left steering axis shortens, the silicone pad detaches from the ground, and the robot moves in a straight line; therefore, the robot can turn left with a certain turning radius.

[0072] Step Two: With the robot moving straight, when a sinusoidal voltage is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis intermittently contacts the ground. When the right steering axis extends, the silicone pad anchors to the ground, and the robot turns right around the right steering axis via the bearing. When sinusoidal voltages of different frequencies are applied to the steering axis, the robot's turning radius also changes. When the right steering axis shortens, the silicone pad detaches from the ground, and the robot moves straight; therefore, the robot can turn right with a certain turning radius.

[0073] This invention allows the robot's speed to change when different waveforms, frequencies, and amplitudes of drive signals are applied to the actuator. The robot's maximum crawling speed is 138 mm / s under a 3.4 kV, 100 Hz drive voltage. The robot can effectively crawl with a load of 200 g (20 times its own weight) at a maximum speed of 15.6 mm / s. It can crawl on slopes of 5, 10, and 15 degrees. The robot can perform left turns, right turns, and U-turns.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A soft crawling robot, characterized in that: The device includes a front support module (1), a rear support module (6), a strip driver (3), a first telescopic mechanism (4), and a first linear spring (5). The front support module (1) and the rear support module (6) are both provided with friction feet. The strip driver (3) includes two parts, one above the other, which connect the front support module (1) and the rear support module (6) and form a cavity with the front support module (1) and the rear support module (6). The first telescopic mechanism (4) and the first linear spring (5) are arranged between the cavity formed by the front support module (1), the rear support module (6), and the strip driver (3). The first telescopic mechanism (4) passes through the first linear spring (5). The strip driver (3) and the compressed first linear spring (5) are in a balanced state. The front support module (1) and the rear support module (6) are concave. The concave platform of the rear support module (6) is provided with a left steering shaft (8) and a right steering shaft (9). The strip driver (3) is attached to the upper and lower sides of the front support module (1) and the rear support module (6) by double-sided tape. It includes a first dielectric elastomer (10), a first conductive rubber (11) and a first copper wire (12). The first conductive rubber (11) is attached to both sides of the first dielectric elastomer (10). The first conductive rubber (11) on both sides is connected to the high voltage amplifier through the first copper wire (12). The signal generator generates an AC signal to power the strip driver (3) to the high voltage amplifier. The left steering shaft (8) and right steering shaft (9) are cylindrical and each includes a cylindrical actuator (13), a capillary tube (14), a bearing (15), a bearing sleeve (16), and a silicone sheet (17). The inner diameter of the bearing (15) is larger than the outer diameter of the capillary tube (14) and is directly fitted onto the capillary tube (14). The bearing sleeve (16) is fitted onto the outer diameter of the bearing (15). The circular silicone sheet (17) is connected to the lower end of the bearing sleeve (16) parallel to the ground using double-sided tape. The columnar actuator (13) includes a second dielectric elastomer (20), a second conductive rubber (21), a second copper wire (25), an upper end cover (18), a second telescopic mechanism (23), a second linear spring (22), and a lower end cover (19). The second dielectric elastomer (20) is attached to both sides with the second conductive rubber (21), and is led out by the second copper wire (25) and fixed to the upper end cover (18) and the lower end cover (19) by double-sided tape (24). The upper end cover (18) and the lower end cover (19) are provided with cylindrical holes in the middle, and capillaries of different diameters are fixed to the upper end cover (18) and the lower end cover (19) respectively to form the second telescopic mechanism (23). The second linear spring (22) is sleeved on the capillary of the second telescopic mechanism (23). The outer diameter of the capillary at the lower end of the steering shaft is smaller than the inner diameter of the capillary at the lower end cover of the columnar actuator. The capillary at the lower end of the steering shaft is directly inserted into the capillary of the second telescopic mechanism of the columnar actuator. The first telescopic mechanism (4) includes two capillaries of the same length.

2. The soft crawling robot according to claim 1, characterized in that: The friction foot is at a 45-degree angle to the ground.

3. A soft crawling robot according to claim 1, characterized in that: The front support module (1) and the rear support module (6) are made of PLA material and printed by a 3D printer.

4. A soft crawling robot according to claim 1, characterized in that: include: (1) Straight-through phase: When the upper and lower strip actuators are powered on, the strip actuators extend along the direction of the first linear spring force, the robot's front support module moves forward, and the rear support module remains stationary; When the strip actuator is de-energized, the first linear spring is compressed, the robot body shortens, the robot's rear support module moves forward, and the front support module remains stationary. A sine wave is continuously supplied to the strip actuator, with a voltage set to a certain amplitude and period, and the soft crawling robot continues to crawl forward. (2) Turning around: Based on the robot's straight-line movement, when DC power is applied to the left steering axis of the crawling robot, the silicone pad at the end of the left steering axis contacts the ground. Continuous power supply anchors the silicone pad of the left steering axis to the ground, and the robot turns left and around the left steering axis through the bearing. Based on the robot's straight-line movement, when DC power is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis contacts the ground. Continuous power supply anchors the silicone pad at the end of the right steering axis to the ground, and the robot turns right and turns around the right steering axis through the bearing. (3) Turning phase: Based on the robot's straight-line movement, when a sinusoidal voltage is applied to the right steering axis of the crawling robot, the silicone pad at the end of the right steering axis intermittently contacts the ground. When the right steering axis extends, the silicone pad is anchored to the ground, and the robot rotates to the right around the right steering axis through the bearing. When sinusoidal voltages of different frequencies are applied to the steering axis, the robot's turning radius changes. When the right steering axis shortens, the silicone pad detaches from the ground, and the robot moves straight.

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