A crocodile-like soft-crawling robot, its control method and system

Abstract

This invention proposes a crocodile-like soft-crawling robot, its control method, and a system. By analyzing the biological structure and movement characteristics of crocodiles, the proposed crocodile-like soft-crawling robot includes a head structure, a torso soft actuator, a tail actuator, leg soft actuators, and connecting components. The left and right chambers of the torso soft actuator, the upper end of the leg actuator, and the lower end of the leg actuator are used to generate deformations in different directions such as forward, backward, left, right, and up and down, thereby enabling the robot to move forward, jump, turn, climb slopes, and perform other gaits, improving the robot's degrees of freedom of movement and allowing the crocodile-like soft-crawling robot to operate stably in both aquatic and terrestrial environments.

Description

Technical Field

[0001] This invention belongs to the field of soft robot technology, and particularly relates to a crocodile-like soft crawling robot, its control method, and system. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] As the application fields of robotics continue to expand, the external environments robots face are becoming more complex and diverse. However, limited by rigid materials and complex structures, traditional rigid robots struggle to operate efficiently in non-standardized environments. Therefore, to enhance environmental adaptability, researchers have designed soft robots that mimic the structural features and movement characteristics of biological organisms. Compared to rigid robots, soft robots are primarily made of flexible materials and possess advantages such as simple structure, lightweight design, and user-friendly human interaction, making them highly promising for applications in critical fields such as disaster relief, military reconnaissance, and medical rehabilitation.

[0004] As an important form of soft robotics, soft crawling robots primarily rely on spatial transformations caused by the deformation of their soft actuators and the friction generated between the deformed actuators and the contact surface for movement. However, most existing soft crawling robots mimic the simple structures and gaits of small animals, resulting in problems such as slow movement speed, weak load capacity, and low actuation efficiency. Specifically, soft crawling robots typically employ peristalsis, flexion-extension, and suction-based movements, leading to a significant consumption of time and energy to maintain their posture during movement, thus reducing efficiency. Furthermore, the small size of soft crawling robots also affects the speed and stability of their movement. In addition, current applications of soft crawling robots mainly depend on manual operation, resulting in low levels of robot intelligence and difficulty in achieving autonomous and precise movement, failing to meet the growing practical application demands of robotics.

[0005] Therefore, how to analyze the structure and gait of large reptiles and design a flexible and stable new soft crawling robot is an urgent problem to be solved. In addition, how to accurately and comprehensively feed back the motion information of the soft crawling robot and its components, and how to drive the soft crawling robot to complete a variety of complex movements accurately and stably are of great significance for the research of soft crawling robots with strong motion performance and high level of intelligence. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a crocodile-like soft-crawling robot, a control method, and a system. The crocodile-like soft-crawling robot includes a head structure, a torso soft actuator, a tail actuator, leg soft actuators, and connecting components, which generate deformations in different directions such as forward, backward, left, right, up, and down, thereby enabling the robot to move forward, jump, turn, climb slopes, and other gaits, improving the robot's degree of freedom of movement, and enabling the crocodile-like soft-crawling robot to operate quickly and stably in aquatic and terrestrial environments.

[0007] To achieve the above objectives, a first aspect of the present invention provides a crocodile-like soft-crawling robot, comprising: a head structure, a torso soft actuator, a tail actuator, leg soft actuators, and a connecting assembly; the head structure is mounted at the front end of the torso soft actuator via the connecting assembly, the tail actuator is mounted at the rear end of the torso soft actuator via the connecting assembly, and a plurality of leg soft actuators are mounted in pairs on both sides of the torso soft actuator via the connecting assembly;

[0008] The trunk soft actuator includes a symmetrical, independent trunk soft actuator left chamber and a trunk soft actuator right chamber with opposite bending directions, used to generate deformation in the left and right directions.

[0009] The leg soft actuator includes an upper leg actuator and a lower leg actuator perpendicular to the bending direction, used to generate deformation in the up-down and back-forward directions.

[0010] The second aspect of the present invention provides a control method for a crocodile-like soft-crawling robot, which employs the aforementioned crocodile-like soft-crawling robot. The motion modes of the crocodile-like soft-crawling robot include three motion modules: land motion, water motion, and waterway motion switching.

[0011] In the land motion mode, periodic air pressure is applied to the leg soft actuators to enable the alligator-like soft crawling robot to crawl in a straight line on a plane and climb slopes.

[0012] A constant air pressure is applied to the soft actuators of the legs on the inside of the turn, while a periodic square wave air pressure is applied to the soft actuators of the legs and the outside of the soft actuators of the torso on the outside of the turn, so as to realize the turning and crawling of the crocodile-like soft crawling robot.

[0013] During the underwater motion mode, high-frequency square wave air pressure is applied to the leg soft actuator to cause the leg soft actuator to reciprocate and propel water, while high-frequency square wave air pressure is applied to the tail soft actuator to make it swing left and right to propel water.

[0014] During the water-based motion switching mode, negative pressure is applied to the left and right front leg soft actuators to lift the crocodile-like soft crawling robot out of the water and onto the land surface. Then, constant positive pressure is applied to the left and right front leg soft actuators to fix the front end of the crocodile-like soft crawling robot onto the land surface. At this time, periodic square wave air pressure is applied to the left and right rear leg soft actuators to move the crocodile-like soft crawling robot toward the land surface, thus achieving a leap.

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

[0016] Acquire continuous motion image information, depth information, and actuator deformation information of the crocodile-like soft crawling robot;

[0017] The marker points of the alligator-like soft-crawling robot are extracted after filtering the continuous motion image information of the alligator-like soft-crawling robot.

[0018] The three-dimensional coordinates of the changing marker points are obtained based on the depth information and the marker points themselves.

[0019] The motion parameters of the crocodile-like soft-crawling robot are obtained based on the three-dimensional coordinates of the changing marker points.

[0020] Based on the robot's motion parameters and actuator deformation information, different amplitudes, frequencies, waveforms, and durations of actuator fluid pressure are applied to control the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

[0021] A fourth aspect of the present invention is a control system for a crocodile-like soft-crawling robot, comprising:

[0022] Industrial cameras are used to acquire continuous motion images of crocodile-like soft-crawling robots;

[0023] A depth camera is used to obtain the vertical distance from the crocodile-like soft-crawling robot to the camera;

[0024] The control host is used to extract the marker points of the alligator-like soft crawling robot after filtering the continuous motion images of the robot; to obtain the three-dimensional coordinates of the marker point changes based on the depth information and the marker points; to obtain the motion parameters of the alligator-like soft crawling robot based on the three-dimensional coordinates of the marker point changes; and to apply different amplitudes, frequencies, waveforms, and durations of the actuator fluid pressure according to the robot motion parameters and actuator deformation information, thereby controlling the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

[0025] The above one or more technical solutions have the following beneficial effects:

[0026] In this invention, by analyzing the biological structure and movement characteristics of crocodiles, a proposed crocodile-inspired soft-crawling robot includes: a head structure, a torso soft actuator, a tail actuator, leg soft actuators, and connecting components. The left and right chambers of the torso soft actuator, the upper end of the leg actuator, and the lower end of the leg actuator are used to generate deformations in different directions (forward, backward, left, right, up, and down), thereby enabling the robot to move forward, jump, turn, and climb slopes, improving the robot's degrees of freedom of movement and allowing the crocodile-inspired soft-crawling robot to operate quickly and stably in aquatic and terrestrial environments. The use of a combined soft actuator approach solves the problems commonly found in current soft-crawling robots, such as slow movement speed, weak load capacity, and limited actuation methods.

[0027] In this invention, by analyzing the biological structure and movement characteristics of crocodiles, different fluid controls are applied to the actuators of various parts of the proposed crocodile-inspired soft-crawling robot, thereby enabling the crocodile-inspired soft-crawling robot to achieve three different movement modes: water movement, land movement, and water-way switching. This overcomes the difficulty of crossing the water and land planes and demonstrates the movement performance and amphibious performance of the proposed crocodile-inspired soft-crawling robot.

[0028] In this invention, by changing factors such as the pressure and frequency of the fluid supplied by each actuator, stable swimming in water is achieved and the difficulty of crossing the water-land plane is overcome, demonstrating the motion performance and amphibious performance of the crocodile-like soft-crawling robot.

[0029] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] 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 improper limitation of the invention.

[0031] Figure 1 This is a schematic diagram of the overall structure of the crocodile-like soft-crawling robot in Embodiment 1 of the present invention;

[0032] Figure 2 This is a schematic diagram of the leg soft actuator structure in Embodiment 1 of the present invention;

[0033] Figure 3 This is a schematic diagram of the trunk software driver structure in Embodiment 1 of the present invention;

[0034] Figure 4 This is a schematic diagram of the tail drive structure in Embodiment 1 of the present invention;

[0035] Figure 5 This is a schematic diagram of the head structure in Embodiment 1 of the present invention;

[0036] Figure 6 This is a schematic diagram of the connection component structure in Embodiment 1 of the present invention;

[0037] Figure 7 This is a schematic diagram of the perception system of the crocodile-like soft-crawling robot in Embodiment 4 of the present invention;

[0038] Figure 8 This is a schematic diagram of the control system for the crocodile-like soft-crawling robot in Embodiment 3 of the present invention;

[0039] Figure 9 This is a basic motion diagram of the crocodile-like soft-crawling robot in Embodiment 2 of the present invention.

[0040] In the picture:

[0041] 1. Left foreleg actuator; 2. Left hind leg actuator; 3. Right foreleg actuator; 4. Right hind leg actuator; 5. Torso actuator; 6. Tail soft actuator; 7. Head structure; 8. Tail tip structure; 9. Front connecting assembly; 10. Rear connecting assembly; 11. Head mounting socket; 12. Torso front mounting socket; 13. Torso rear mounting socket; 14. Tail mounting socket; 15. Front connecting assembly circular connector; 16. Torso actuator circular connector; 17. Rear connecting assembly circular connector. 18. Tail driver circular connector, 19. Leg driver lower end, 20. Leg soft driver upper end, 21. Trunk soft driver right chamber, 22. Trunk soft driver left chamber, 23. Trunk driver common bottom surface, 24. Tail right soft driver, 25. Tail left soft driver, 26. Tail close to bottom surface, 27. Planar trapezoidal tail tip, 28. Flat quadrangular frustum head, 29. Connecting component circular connector, 30. Connecting component square connector, 31. Connecting component horizontal connector. Detailed Implementation

[0042] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0044] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0045] Example 1

[0046] like Figure 1As shown, this embodiment discloses a crocodile-like soft-crawling robot, including: a head structure 7, a torso soft actuator 5, a tail actuator 6, leg soft actuators, and a connecting assembly; the head structure 7 is mounted on the front end of the torso soft actuator 5 through the connecting assembly, the tail actuator 6 is mounted on the rear end of the torso soft actuator 5 through the connecting assembly, and multiple leg soft actuators are mounted in pairs on both sides of the torso soft actuator 5 through the connecting assembly.

[0047] The trunk soft actuator 5 includes a symmetrical, independent trunk soft actuator left chamber 22 and a trunk soft actuator right chamber 21 with opposite bending directions, for generating deformation in the left and right directions.

[0048] The leg soft actuator includes an upper leg actuator 20 and a lower leg actuator 21 perpendicular to the bending direction, used to generate deformation in the up-down and back-forward directions.

[0049] In this embodiment, the crocodile-like soft crawling robot is in the form of a left front leg actuator 1, a left hind leg actuator 2, a right front leg actuator 3, and a right hind leg actuator 4.

[0050] The left front leg actuator 1 and the left rear leg actuator 2 have the same structure, the right front leg actuator 3 and the right rear leg actuator 4 have the same structure, and the left front leg actuator 1 and the right front leg actuator 3 are symmetrical to each other.

[0051] Taking the right front leg actuator 3 as an example, such as Figure 2 As shown, the complete structure of the leg actuator includes a lower end 19 and an upper end 20, which correspond to the lower leg and thigh parts, respectively, mimicking the crocodile leg. Both the lower end 19 and the upper end 20 are sized mesh-type soft actuators. The lower end 19 and the upper end 20 are connected by a fluid tube.

[0052] Specifically, one end of the upper leg actuator 20 is mounted on the torso soft actuator 5 via a connecting component, and the lower leg actuator 19 is connected to the other end of the upper leg actuator 20. The upper leg actuator 20 and the lower leg actuator 19 are two mesh-type soft actuators with mutually perpendicular bending directions, made of silicone rubber material, which can simultaneously produce vertical and horizontal deformation relative to the body of the crocodile-like soft crawling robot.

[0053] In this embodiment, both the torso soft actuator 5 and the tail actuator 6 are planar deformation soft actuators, inspired by the torso and tail of a crocodile, such as... Figure 1 As shown, the crocodile-like soft-crawling robot consists of a combination of a torso soft actuator 5, a tail soft actuator 6, and a tail tip structure 8. The specific structures of these components are as follows: Figure 2 As shown.

[0054] like Figure 3 As shown, the torso soft actuator 5 is a planar deformation soft actuator, which consists of two mesh-type soft actuators with opposite bending directions and a common bottom surface. It is made of silicone rubber material. Each of the two mesh-type soft actuators contains an independent fluid passage, which can produce left and right deformation relative to the body of the crocodile-like soft crawling robot.

[0055] Specifically, the trunk soft actuator 5 includes a right trunk soft actuator chamber 21, a left trunk soft actuator chamber 22, and a common bottom surface 23 of the trunk actuator, which respectively mimic the right side tissue, left side tissue, and spine of the crocodile trunk.

[0056] The right chamber 21 of the trunk software actuator and the left chamber 22 of the trunk software actuator each contain several mesh-type software chambers of varying lengths, and their chamber orientations are opposite.

[0057] The common bottom surface 23 of the torso actuator is a solid cuboid with a certain thickness. It is the common bottom surface of the right chamber 21 and the left chamber 22 of the torso actuator and serves to support the torso actuator. The entire torso soft actuator 5 can bend in the left and right directions relative to the crocodile-like soft crawling robot, which can assist the crocodile-like soft crawling robot in turning movements.

[0058] In this embodiment, as Figure 4 As shown, the tail actuator 6 consists of a planar deformation soft actuator and a tail tip structure. The planar deformation soft actuator comprises two independent mesh-like soft actuators with opposite bending directions and tightly fitted bottom surfaces, made of silicone rubber, and capable of lateral deformation relative to the robot body. The tail tip structure is non-deformable and directly connected to one end of the planar deformation soft actuator. It is made of a non-elastic rigid material and can have different shapes such as a planar trapezoid or a vertical cuboid, depending on different functional requirements such as crawling and swimming.

[0059] Specifically, the tail soft actuator 6 comprises a right tail soft actuator 24, a left tail soft actuator 25, a tail-adhering bottom surface 26, and a tail tip structure 8. The tail soft actuator structure is similar to that of the torso actuator. The right tail soft actuator 24 and the left tail soft actuator 25 are symmetrically arranged and bend in opposite directions. The tail-adhering bottom surface 26 is a shared bottom surface of the right tail soft actuator 24 and the left tail soft actuator 25, and can bend in the left-right direction relative to the robot.

[0060] The tail tip structure 8 is a 3D-printed, non-deformable structure that assists in movement. Depending on the specific functional requirements such as crawling or swimming, it can have different structures, such as a planar trapezoid or a vertical cuboid. For example... Figure 4As shown, when the crocodile-like soft crawling robot moves on a land plane, the tail tip structure 8 can specifically be a planar trapezoidal tail tip 27.

[0061] In this embodiment, the head structure 7 is non-deformable, has a flat truncated quadrangular shape, and is made of a non-elastic rigid material.

[0062] Specifically, head structure 7 is a 3D-printed, non-deformable structure inspired by the head of a crocodile. Figure 1 The crocodile-like soft-crawling robot shown is represented by a head structure 7. The head structure primarily serves to complete the robot's overall structure and provide space for mounting sensing devices; its design can be tailored to specific needs. For example... Figure 5 As shown, the head structure 7 can specifically be a flat quadrangular frustum head 28.

[0063] In this embodiment, the connecting component is a 3D-printed, non-deformable structure used to connect the various parts of the robot, such as... Figure 1 As shown, the alligator-like soft crawling robot exists in the form of a front connecting component 9 and a rear connecting component 10.

[0064] like Figure 6 As shown, the connecting component is generally cuboid in shape and made of a non-elastic rigid material. On each of the left and right sides of the connecting component, there is a recessed square socket 30 for the leg soft actuator to be inserted. Two circular holes 29 are provided on the upper surface of the connecting component for connecting fluid pipes. The two circular holes 29 correspond to the recessed square sockets 30 on the left and right sides, respectively, and are connected by a right-angled cavity inside the connecting component, forming two independent fluid pathways. Specifically, there is also a horizontal hole 31 at the square socket 30. The horizontal hole 31 is used to supply fluid to the leg actuator. The circular hole 29 and the horizontal hole 31 are directly connected through a vertical channel in the connecting component, facilitating fluid supply to the leg actuator and preventing the fluid pipe from being directly inserted into the leg actuator and affecting its deformation.

[0065] The connecting components are divided into a front connecting component 9 and a rear connecting component 10. The front end of the torso soft driver 5 is connected to the upper surface of the front connecting component 9 via a torso front fixing socket 12 and a fastening rod. The rear end of the torso soft driver 5 is connected to the upper surface of the rear connecting component 10 via a torso rear fixing socket 13 and a fastening rod. The left front leg driver 1 and the right front leg driver 3 are respectively inserted into the square sockets 30 at the left and right ends of the front connecting component 9, and the left rear leg driver 2 and the right rear leg driver 4 are respectively inserted into the square sockets 30 at the left and right ends of the rear connecting component 10.

[0066] The head structure 7 is combined with the upper surface of the front connecting component 9 via the head fixing socket 11 and the fastening rod. The tail soft actuator 6 is combined with the upper surface of the rear connecting component 10 via the tail fixing socket 14 and the fastening rod. The circular connector 15 of the front connecting component, the circular connector 16 of the torso soft actuator, the circular connector 17 of the rear connecting component, and the circular connector 18 of the tail actuator are all connected to fluid pipes, which can independently supply fluid of a specific pressure to the leg actuators, torso soft actuators, and tail actuators, causing each leg soft actuator to undergo spatial deformation to drive the alligator-like soft crawling robot to move. It can also cause the torso soft actuators and tail actuators to bend to assist the movement of the alligator-like soft crawling robot.

[0067] In this embodiment, each independent fluid passage in the crocodile-like soft crawling robot is connected to a corresponding fluid pipe and a fluid proportioning valve.

[0068] In this embodiment, the head structure 7, the connecting component, and the tail tip structure 8 are all 3D printed using non-elastic rigid materials based on the design model. The soft parts in the leg soft actuator, the torso soft actuator, and the tail actuator are all made using silicone rubber casting technology based on their respective different structures.

[0069] In this embodiment, the fluid used is gas; other fluids can be used simply by replacing the fluid source and the fluid proportioning valve.

[0070] It should be noted that, in this embodiment, "left" and "right" are used to describe the forward movement direction of the crocodile-like soft crawling robot as forward and the backward movement direction as backward.

[0071] Example 2

[0072] This embodiment provides a control method for a crocodile-like soft-crawling robot, which is applied to a crocodile-like soft-crawling robot as described in Embodiment 1. The motion modes of the crocodile-like soft-crawling robot include three motion modules: land motion, water motion, and waterway motion switching.

[0073] In the land motion mode, periodic square wave air pressure is applied to the leg soft actuators to realize the alligator-like soft crawling robot's planar straight-line crawling and slope climbing;

[0074] A constant air pressure is applied to the soft actuators of the legs on the inside of the turn, while a periodic square wave air pressure is applied to the soft actuators of the legs and the outside of the soft actuators of the torso on the outside of the turn, so as to realize the turning and crawling of the crocodile-like soft crawling robot.

[0075] During the water motion mode, high-frequency square wave air pressure is applied to the leg soft actuator to cause the leg soft actuator to reciprocate and propel water, while high-frequency square wave air pressure is applied to the tail soft actuator to make it swing left and right to propel water.

[0076] When switching between water and land movement modes, negative pressure is applied to the soft actuators of the left and right front legs to lift the crocodile-like soft crawling robot out of the water and onto the land surface. Then, a constant positive pressure is applied to the soft actuators of the left and right front legs to fix the front end of the crocodile-like soft crawling robot on the land surface. At this time, periodic square wave air pressure is applied to the soft actuators of the left and right hind legs to move the crocodile-like soft crawling robot towards the land surface, thus achieving a leap.

[0077] like Figure 9 As shown, when the alligator-like soft-crawling robot moves on land, by simultaneously applying periodic square wave air pressure to its four leg actuators, the robot can achieve both straight-line crawling and slope climbing. The square wave air pressure is specifically represented as:

[0078]

[0079] Where p(t) is the air pressure value at time t, A is the amplitude of the square wave, and T is the period of the square wave. Specifically, when the applied air pressure amplitude exceeds a certain threshold, the four leg actuators will significantly lift, raising the robot body to a certain height and forming a jumping gait. By applying constant air pressure to the two inner leg actuators for turning, and applying periodic square wave air pressure to the two outer leg actuators for turning and the outer side of the torso actuators, the alligator-like soft-body crawling robot can achieve turning and crawling.

[0080] When the robot moves in water, a higher-frequency (higher frequency than the square wave frequency for land motion) square wave air pressure is simultaneously applied to the four leg actuators, causing them to reciprocate more rapidly to effectively part the water. Simultaneously, a high-frequency (higher frequency than the square wave frequency for land motion) square wave air pressure is sequentially applied to the two independent chambers of the tail soft actuator, causing it to rapidly oscillate left and right to part the water. With the cooperation of the leg and tail actuators, the crocodile-like soft-crawling robot can swim stably and quickly in water. Specifically, when the crocodile-like soft-crawling robot crosses from the water surface to the land surface, negative pressure is applied to the left and right front leg actuators to lift them from the water and land them on the land surface. Then, a constant positive pressure is applied to them to fix the robot's front end on the land surface. At this point, periodic square wave air pressure is applied to the left and right rear leg actuators, causing the robot to gradually move towards the land surface, ultimately achieving the crossing.

[0081] Example 3

[0082] This embodiment discloses a control system for a crocodile-like soft-crawling robot, including:

[0083] Industrial cameras are used to acquire continuous motion images of crocodile-like soft-crawling robots;

[0084] Depth camera, used to acquire depth information of crocodile-like soft-crawling robot;

[0085] The control host is used to extract the marker points of the alligator-like soft crawling robot after filtering the continuous motion images of the robot; to obtain the three-dimensional coordinates of the marker point changes based on the depth information and the marker points; to obtain the motion parameters of the alligator-like soft crawling robot based on the three-dimensional coordinates of the marker point changes; and to apply different amplitudes, frequencies, waveforms, and durations of the actuator fluid pressure according to the robot motion parameters and actuator deformation information, thereby controlling the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

[0086] Specifically, multiple industrial cameras and depth cameras are positioned directly above and at a certain distance around the alligator-like soft-bodied crawling robot to capture image information as the robot begins to move. The industrial cameras are connected to the control host via gigabit Ethernet cables, enabling real-time transmission of high-resolution images of the robot and its actuators. Multiple industrial and depth cameras are used to comprehensively acquire motion information from the alligator-like soft-bodied crawling robot and its actuators. The depth cameras are connected to the control host via data cables, accurately providing depth information from the images.

[0087] After receiving the information from both, the control host runs visual inspection and coordinate extraction algorithms. The visual inspection algorithm uses image preprocessing, contour extraction, and corner detection to obtain the landmark points of the alligator-like soft-crawling robot and its actuators, including but not limited to the start and end points of the actuators, the head and tail points of the robot, and the endpoints of the connections between components. The coordinate extraction algorithm calibrates the industrial cameras and depth cameras at various locations, obtains the transformation relationship between each pixel's coordinate system and the world coordinate system, and, combined with the depth information obtained from the depth camera, extracts the actual three-dimensional coordinates of the landmark points.

[0088] The algorithm running in the control host issues control signals after calculation. These signals are processed and converted into analog signals and sent to the fluid proportional valve. Under the influence of the analog signals, the fluid proportional valve controls the fluid flow rate and feeds back the fluid pressure to the control host in the form of analog signals. Simultaneously, each soft actuator deforms under the influence of the fluid. The deformation information of the actuators, as well as the motion information generated by the alligator-like soft crawling robot due to the deformation, is collected by the sensing system and fed back to the control host for calculation. The feedback of the fluid pressure inside the actuators and the motion coordinates of the alligator-like soft crawling robot and its actuators serve as the basis for the control algorithm's calculations.

[0089] The basic gait planning of the alligator-like soft-crawling robot includes the basic motion planning for forward movement, jumping, turning, and climbing. By analyzing the position and cooperative relationship between the actuators in the alligator-like soft-crawling robot, and using the designed perception and control system, fluid pressures of different amplitudes, frequencies, waveforms, and durations are applied to each actuator, causing different degrees of deformation at different times, forming cooperative motion among the actuators, and ultimately enabling the robot to complete the above movements efficiently and stably.

[0090] The control host controls the motion modes of the crocodile-like soft-crawling robot in both aquatic and terrestrial environments, including the robot's land movement, water movement, and the switching between land and water movements.

[0091] Specifically, land movement is the basic gait of the aforementioned crocodile-like soft-crawling robot; water movement requires the leg and tail actuators to swing back and forth and left and right at higher frequencies, respectively, to propel the robot forward in the water; switching between land and water movement requires the two front leg actuators of the robot to lift and cross the plane and bend and grip the plane, so that the robot can move from the water surface to the land surface, while the pushing action of the two rear leg actuators of the robot can make the robot enter the water from the land surface.

[0092] like Figure 8 As shown, the control host sends control signals according to the execution algorithm. After signal processing and conversion, a control voltage is generated to control the opening degree of the air passage inside the proportional valve. At the same time, the air pump can provide gas at a certain pressure, which is supplied to the software actuator through each proportional valve to cause it to deform.

[0093] The internal air pressure of each soft actuator is sent to the control host in the form of feedback voltage for processing. In addition, the deformation information of each soft actuator is fed back to the control host for processing via industrial cameras and depth cameras, and the motion information of the alligator-like soft crawling robot is fed back to the control host via images acquired by industrial cameras and depth cameras for processing. The control host calculates and generates control signals based on the information from both, forming a complete closed-loop control system.

[0094] This embodiment establishes a control system for a crocodile-like soft-crawling robot, enabling the planning of the robot's basic gait, such as forward movement and jumping, and controlling the robot to operate stably in both aquatic and terrestrial environments. Ultimately, this results in a crocodile-like soft-crawling robot and system that features high speed, strong load capacity, and autonomous, precise movement.

[0095] The control system can provide fluid with a specific pressure to all independent fluid passages of the robot according to the given control signal, and can also process and calculate the pressure and motion information in real time, laying the foundation for the intelligent control of the crocodile-like soft crawling robot.

[0096] Under the combined action of the aforementioned perception and control system, the planned basic gait of the crocodile-like soft-crawling robot improves its motion stability and efficiency on various planes, enabling effective motion cooperation among the various actuators and allowing it to better complete various tasks. Simultaneously, considering the complexities of aquatic and terrestrial environments, the crocodile-like soft-crawling robot can achieve stable swimming in water and overcome the difficulties of crossing land and water planes by changing factors such as the pressure, frequency, and time of the fluid supplied by each actuator, demonstrating its motion performance and amphibious capabilities.

[0097] Example 4

[0098] like Figure 7 As shown, this embodiment provides a control method for a crocodile-like soft-crawling robot, including:

[0099] Acquire continuous motion image information, depth information, and actuator deformation information of the alligator-like soft-crawling robot;

[0100] The marker points of the alligator-like soft-crawling robot are extracted after filtering the continuous motion image information of the alligator-like soft-crawling robot.

[0101] The three-dimensional coordinates of the changing marker points are obtained based on the depth information and the marker points themselves.

[0102] The motion parameters of the crocodile-like soft-crawling robot are obtained based on the three-dimensional coordinates of the changing marker points.

[0103] Based on the robot's motion parameters and actuator deformation information, different amplitudes, frequencies, waveforms, and durations of actuator fluid pressure are applied to control the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

[0104] First, Gaussian filtering is used to reduce noise in the image. Then, a contour extraction algorithm is used to obtain the contours of the robot and its actuator, and a corner extraction algorithm is used to obtain the corresponding landmarks. When tracking landmarks in continuous images, a Kalman filter target tracking algorithm is used, specifically:

[0105] x k =Fx k-1 +Bu k +w k-1 ,

[0106] z k =Hx k +v k ,

[0107] Where, x k Let F represent the position and velocity vectors of the robot at time k, F represent the state prediction matrix of the robot, B represent the control input matrix, and u represent the position and velocity vectors of the robot at time k.k This indicates the air pressure control input for the robot, w k-1 z represents the noise in the robot system. k Let H represent the observation vector of the robot's position and velocity at time k, and let H represent the observation matrix. k This indicates the observation noise for the robot.

[0108] The accurate z-coordinates of marker points can be directly obtained from the depth information fed back by the depth camera. Based on the calibration matrices of cameras at each position, the x and y coordinates of pixel coordinate points are sequentially transformed into the camera coordinate system and the world coordinate system via transformation matrices, ultimately yielding the x and y coordinates of the marker point. Combined with the previously obtained z-coordinates, this constitutes the complete three-dimensional coordinates of the marker point, which can be calculated in real time. In continuously acquired video, the displacement and velocity of the robot can be calculated by subtracting the three-dimensional coordinates of different marker points before and after fixed time intervals, thus obtaining the motion parameters of the crocodile-like soft-crawling robot.

[0109] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A crocodile-like soft-crawling robot, characterized in that, include: The device includes a head structure, a torso soft actuator, a tail actuator, leg soft actuators, and a connecting assembly. The head structure is mounted at the front end of the torso soft actuator via the connecting assembly, the tail actuator is mounted at the rear end of the torso soft actuator via the connecting assembly, and a plurality of leg soft actuators are mounted in pairs on both sides of the torso soft actuator via the connecting assembly. The torso soft actuator includes a symmetrical, independent left chamber and a right chamber of the torso soft actuator with opposite bending directions, used to generate deformation in the left and right directions; the left chamber and the right chamber of the torso soft actuator each include multiple grid-shaped soft chambers of different lengths. The leg soft actuator includes an upper leg actuator and a lower leg actuator perpendicular to the bending direction, used to generate deformation in the up-down and back-forward directions.

2. The alligator-like soft-body crawling robot as described in claim 1, characterized in that, One end of the upper part of the leg driver is mounted on the torso software driver via the connecting assembly, and the lower end of the leg driver is connected to the other end of the upper part of the leg driver.

3. The alligator-like soft-body crawling robot as described in claim 1, characterized in that, The trunk software driver also includes a common bottom surface of the trunk driver, and the left chamber and the right chamber of the trunk software driver are mounted on the common bottom surface of the trunk driver.

4. The alligator-like soft-body crawling robot as described in claim 1, characterized in that, The tail actuator includes a symmetrical, independent tail right soft actuator and a tail left soft actuator with opposite curvatures, as well as a tail bottom surface and a tail tip structure; the tail right soft actuator and the tail left soft actuator are mounted on the tail bottom surface; One end of the bottom surface of the tail is mounted on the rear end of the trunk software actuator via a connecting component; the other end of the bottom surface of the tail is connected to the tail tip structure; the right tail software actuator and the left tail software actuator are used to generate deformation in the left and right directions.

5. The alligator-like soft-body crawling robot as described in claim 1, characterized in that, The connecting assembly includes a front connecting assembly and a rear connecting assembly. One opposite side of the front connecting assembly is respectively connected to the front end of the head structure and the torso software actuator, and the other opposite side of the front connecting assembly is respectively connected to the left front leg actuator and the right front leg actuator. The rear connecting component is connected to the rear end and tail driver of the torso software driver on one opposite side, and the rear connecting component is connected to the left rear leg driver and right rear leg driver on the other opposite side. The connecting assembly has multiple independent fluid channels for supplying fluid to the left hind leg actuator, right hind leg actuator, left front leg actuator, right front leg actuator, left chamber of the trunk soft actuator, right chamber of the trunk soft actuator, right tail soft actuator, and left tail soft actuator, respectively.

6. The alligator-like soft-body crawling robot as described in claim 4, characterized in that, Both the tail tip structure and the head structure are 3D printed non-deformable structures. Alternatively, each independent fluid channel may be equipped with a corresponding fluid proportioning valve.

7. A control method for a crocodile-like soft-crawling robot, applied to the crocodile-like soft-crawling robot as described in any one of claims 1-6, characterized in that, The motion modes of the crocodile-like soft crawling robot include three motion modules: land motion, water motion, and waterway motion switching. In the land motion mode, periodic square wave air pressure is applied to the leg soft actuators to realize the alligator-like soft crawling robot's planar straight-line crawling and slope climbing; A constant air pressure is applied to the soft actuators of the legs on the inside of the turn, while a periodic square wave air pressure is applied to the soft actuators of the legs and the outside of the soft actuators of the torso on the outside of the turn, so as to realize the turning and crawling of the crocodile-like soft crawling robot. During the underwater motion mode, high-frequency square wave air pressure is applied to the leg soft actuator to cause the leg soft actuator to reciprocate and deform, while high-frequency square wave air pressure is applied to the tail soft actuator to make it swing left and right to propel the water. During the waterway movement switching mode, negative pressure is applied to the left and right front leg soft actuators to lift the crocodile-like soft crawling robot out of the water and onto the land surface. Then, constant positive pressure is applied to the left and right front leg soft actuators to fix the front end of the crocodile-like soft crawling robot on the land surface. At this time, periodic square wave air pressure is applied to the left and right rear leg soft actuators to move the crocodile-like soft crawling robot toward the land surface, thus achieving waterway crossing.

8. A control method for a crocodile-like soft-crawling robot, applied to the crocodile-like soft-crawling robot as described in any one of claims 1-6, characterized in that, include: Acquire continuous motion image information, depth information, and actuator deformation information of the crocodile-like soft crawling robot; The marker points of the alligator-like soft-crawling robot are extracted after filtering the continuous motion image information of the alligator-like soft-crawling robot. The three-dimensional coordinates of the changing marker points are obtained based on the depth information and the marker points themselves. The motion parameters of the crocodile-like soft-crawling robot are obtained based on the three-dimensional coordinates of the changing marker points. Based on the robot's motion parameters and actuator deformation information, different amplitudes, frequencies, waveforms, and durations of actuator fluid pressure are applied to control the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

9. A control system for a crocodile-like soft-crawling robot, employing the control method for a crocodile-like soft-crawling robot as described in claim 7 or claim 8, characterized in that, include: Industrial cameras are used to acquire continuous motion images of crocodile-like soft-crawling robots; Depth camera, used to acquire depth information of crocodile-like soft-crawling robot; The control host is used to extract the marker points of the alligator-like soft crawling robot after filtering the continuous motion images of the robot; to obtain the three-dimensional coordinates of the marker point changes based on the depth information and the marker points; to obtain the motion parameters of the alligator-like soft crawling robot based on the three-dimensional coordinates of the marker point changes; and to apply different amplitudes, frequencies, waveforms, and durations of the actuator fluid pressure according to the robot motion parameters and actuator deformation information, thereby controlling the movement of the torso soft actuator, tail actuator, and leg soft actuator respectively.

Images