Three-ball pin type flexible continuum robot unit and continuum robot

Abstract

Disclosed are a three-ball-pin type flexible continuum robot unit and a continuum robot. In the three-ball-pin type flexible continuum robot unit, a main structure body is a main part of the entire continuum robot and constitutes an entire mechanical arm; flexible nickel-titanium rods are connected to two adjacent main structure bodies at two ends respectively; a front-end structure body is arranged at the frontmost end of the mechanical arm; and a rear-end structure body is arranged at the rearmost end of the mechanical arm. In use, a single-core-column flexible structure is adopted, and the single-joint has the advantages of multiple degrees of freedom; meanwhile, the three-ball-pin structure and the ball cage structure are wrapped and matched to form rigid constraint and enhance the torsional stiffness, and the flexible single-core column and the three-ball-pin jointly form a rigid-flexible coupled continuum robot unit, and the two complement each other, the single-joint has two degrees of freedom, has the advantages of flexibility, strong adaptability, strong torsional resistance and the like, and is suitable for being applied to various scenes such as medical treatment and detection.

Description

Technical Field

[0001] This invention relates to the field of continuous robot technology, and in particular to a three-ball pin type flexible continuous robot unit and a continuous robot. Background Technology

[0002] Traditional robots are typically constructed from rigid materials and joints. Limited by their rigid structure, these robots exhibit relatively low adaptability and flexibility in complex environments. Continuum robots, on the other hand, utilize soft materials and continuous motion, enabling them to better adapt to complex environments, perform delicate tasks, and interact more naturally with humans. Continuum robots have potential applications in many fields, including medical surgery, disaster relief, and marine exploration. Due to their flexibility and adaptability, they can enter confined spaces, adapt to irregular environments, and play a role in tasks requiring delicate manipulation or high-risk operations.

[0003] The structural design of a continuum robot directly affects its performance. Currently, traditional continuum robots are mainly divided into two mainstream forms: single-core and double-core. Compared to double-core robots, which have only one degree of freedom per joint, single-core continuum robots have multiple degrees of freedom per joint, making them more flexible and versatile. However, traditional single-core continuum robots have extremely poor torsional resistance and cannot withstand large torsional loads, which also leads to poor control accuracy. For example, the structure used in the invention patent "A Bearing-Type Double-Core Continuum Robot" (publication number CN 115556140A) restricts joint torsion through bearings, but in this structure, each joint only focuses on rotation in one direction, limiting its flexibility.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a three-ball-pin flexible continuum robot unit and a continuum robot. It employs a single-core structure, which offers greater flexibility compared to a double-core structure. This ensures that each joint can rotate in multiple directions while maintaining high torsional resistance. The three ball-pin structures, combined with a ball-cage structure, form a rigid joint, enhancing torsional stiffness and creating a rigid-flexible coupling mechanism. Each joint has two degrees of freedom, allowing rotation in all directions. It offers advantages such as flexibility, adaptability, and strong torsional resistance, making it suitable for applications in various scenarios, including medical and exploration applications.

[0006] The objective of this invention is achieved through the following technical solution. The three-ball pin type flexible continuum robot unit includes...

[0007] Multiple main structural components are interconnected to form a robotic arm. The main structural components include...

[0008] The structural body includes three ball cage grooves arranged recessed along the central axis from the top surface. The three ball cage grooves are connected and symmetrically distributed with respect to the central axis to form a ball cage structure.

[0009] A flexible rod hole groove extends through the structural body along its central axis.

[0010] Multiple drive line through holes are located around the ball cage structure and run through the entire structure body.

[0011] The ball pin structure includes three ball pins disposed on the lower surface of the structural body, and the ball pin structure engages and limits the positioning of the ball cage structure of the adjacent structural body above.

[0012] Multiple side grooves are recessed inward from the side surface of the structural body in a direction perpendicular to the central axis.

[0013] Multiple set screw holes are provided on the side surface of the structural body between adjacent side slots and communicate with the flexible rod hole slot;

[0014] A front-end structure, located at the very tip of the robotic arm, includes...

[0015] The structural body includes a central threaded hole extending from the upper surface along the central axis.

[0016] A flexible rod hole groove extends through the structural body along its central axis.

[0017] Multiple drive line through holes are located around the periphery of the structural body and extend through the entire structural body.

[0018] The ball-pin structure includes three ball pins disposed on the lower surface of the structure body.

[0019] Multiple side grooves are recessed inward from the side surface of the structural body in a direction perpendicular to the central axis.

[0020] Multiple set screw holes are provided on the side surface of the structural body between adjacent side slots and communicate with the flexible rod hole slot;

[0021] The rear-end structure, located at the very rear of the robotic arm, includes...

[0022] The structural body includes three ball cage grooves arranged recessed along the central axis from the top surface. The three ball cage grooves are connected and symmetrically distributed with respect to the central axis to form a ball cage structure.

[0023] A flexible rod hole groove extends through the structural body along its central axis.

[0024] Multiple drive line through holes are located around the ball cage structure and run through the entire structure body.

[0025] Multiple side grooves are recessed inward from the side surface of the structural body in a direction perpendicular to the central axis.

[0026] Multiple set screw holes are provided on the side surface of the structural body between adjacent side slots and communicate with the flexible rod hole slot.

[0027] A connecting chassis is located at the bottom of the structural body of the rear unit block, and multiple mounting and fixing holes are distributed around the periphery of the connecting chassis;

[0028] Multiple flexible nickel-titanium rods pass through flexible rod slots in the structural body and are connected via set screws in the set screw holes.

[0029] In the aforementioned three-ball pin flexible continuum robot unit, the main body is a cylindrical structure.

[0030] In the aforementioned three-ball pin type flexible continuum robot unit, the front end structure is threadedly connected to the operating instrument via a central threaded hole.

[0031] In the aforementioned three-ball pin type flexible continuum robot unit, the operating instruments include cameras or searchlights, etc.

[0032] In the aforementioned three-ball pin type flexible continuum robot unit, the rear structure is fixedly connected to the drive control system via mounting holes.

[0033] In the aforementioned three-ball pin flexible continuum robot unit, the ball pin structure and the ball cage structure are in a clearance-fitting wrapping relationship to form a rigid joint.

[0034] In the aforementioned three-ball pin flexible continuum robot unit, the ball pin structure and the ball cage structure cooperate with each other to have a total of 2 degrees of freedom.

[0035] In the aforementioned three-ball pin flexible continuum robot unit, every two main structural members are connected by a flexible nickel-titanium rod, with both ends inserted into flexible rod slots, and then secured from three directions by three set screws through set threaded holes.

[0036] In the aforementioned three-ball pin flexible continuum robot unit, the front-end structure, the main structure, and the rear-end structure are connected in series on the same curved central axis.

[0037] A continuum robot includes the aforementioned three-ball pin type flexible continuum robot unit, wherein multiple drive lines sequentially pass through drive line through holes in the front end structure, the main structure, and the rear end structure to form a continuum robot.

[0038] Compared with the prior art, the advantages of the present invention are:

[0039] 1. This invention adopts a rigid-flexible coupling structure, in which the ball pin structure and the ball cage structure of adjacent structures wrap around each other to form a rigid joint; and a shape memory metal nickel-titanium rod is used as a skeleton support to form a flexible joint. The two complement each other and take into account the advantages of both.

[0040] 2. This invention also adopts a single-core column structure, which improves the rigidity of the robotic arm and allows a single joint to have multiple degrees of freedom. The three ball pin structures and the ball cage structure work together to provide a total of 2 degrees of freedom, enabling rotation in any direction on a single joint, thus improving the flexibility of the continuum robot.

[0041] 3. The present invention also has high torsional resistance. The ball pin structure is placed inside the ball cage. When torsion occurs, the ball joint contacts the inner wall of the ball cage to limit and resist torsion, thereby improving the torsional resistance of the continuum robot.

[0042] 4. The present invention also has a side groove at the position where the wire passes through the side of the unit block. This can reduce the contact between the drive line and the block, thereby reducing the negative impact of friction, and also reducing the overall weight to improve control accuracy.

[0043] The above description is merely an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0044] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0045] In the attached diagram:

[0046] Figure 1 This is a schematic diagram of the three-ball pin type flexible continuum robot unit and the continuum robot of the present invention;

[0047] Figure 2 This is a schematic diagram of the main structure in this invention;

[0048] Figure 3This is a top view of the main structure in this invention;

[0049] Figure 4 This is a side view of the main structure in this invention;

[0050] Figure 5 This is a schematic diagram of the front-end structure in this invention;

[0051] Figure 6 This is a schematic diagram of the backend structure in this invention;

[0052] Figure 7 This is a schematic diagram of the flexible rod connection at the joint in this invention;

[0053] Figure 8 This is a schematic diagram of the deformed continuum robot of the present invention.

[0054] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0055] Specific embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0056] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0057] To facilitate understanding of the embodiments of the present invention, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0058] To better understand, such as Figures 1 to 8As shown, a three-ball pin type flexible continuum robot unit includes a main structure 1, which is the main structure of the entire continuum robot and constitutes the entire robotic arm; a flexible nickel-titanium rod 2, whose two ends are respectively connected to two adjacent main structures 1, and are connected by a flexible rod hole groove 16 and a set screw in a set screw hole 15 to form a flexible joint; a front end structure 3, which is arranged at the front end of the robotic arm; and a rear end structure 4, which is arranged at the rear end of the robotic arm.

[0059] like Figure 2 As shown, the main structure 1 includes a ball cage structure 11, a ball pin structure 12, a drive line through hole 13, a side groove 14, and a set screw hole 15. The ball cage structure 11 is located on the upper part of the main structure 1 and is a ball cage groove opened on the upper surface of the main structure 1. The ball pin structure 12 is located on the lower surface of the main structure 1. The drive line through hole 13 is located around the ball cage structure 11 and penetrates the entire main structure 1. There are three side grooves 14 and three set screw holes 15, which are staggered on the side surface of the main structure 1. The side groove 14 is triangular in shape and is slotted at the position of the drive line through hole 13. The purpose is to reduce the contact between the drive line and the block, thereby reducing the negative impact of friction, and also reducing the overall weight to improve control accuracy.

[0060] like Figure 3 As shown, the ball cage structure 11 has three rail slots with an adjacent included angle of 120° and a hemispherical bottom; the drive line through holes 13 are distributed around the three rail slots and are used to thread the drive rope; the flexible rod hole slot 16 is located at the center of the main structure 1 and is used to connect with the flexible nickel-titanium rod 2.

[0061] like Figure 4 As shown, three ball pin structures 12 are distributed at 120° angles to each other on the lower surface of the main structure 1. Each ball pin structure 12 consists of a spherical structure and a columnar structure connected together. The three spherical structures are installed into the three rail slots of the ball cage structure 11, forming an enclosing relationship with a clearance fit to create a rigid joint. Two arrangement schemes are provided, but not limited to these two: one scheme is that the spherical structure, columnar structure, and main structure 1 are integrally processed, which can be 3D printed; the other scheme is that the spherical structure has a threaded hole, and a threaded rod is processed at one end of the columnar structure, so that the two can be connected by threaded assembly, and the other end of the columnar structure is connected to the main structure 1 by adhesive bonding.

[0062] like Figure 5 As shown, the front end structure 3 includes a central threaded hole 31, a ball pin structure 12, a drive line through hole 13, a side groove 14, and a set threaded hole 15. The central threaded hole 31 is located at the center of the front end structure 3 and is arranged at the front end of the robotic arm. It can be connected to tools such as cameras and searchlights. The rest of the structure is the same as the main structure 1.

[0063] like Figure 6 As shown, the rear structure 4 includes a connecting chassis 41, mounting holes 42, a ball cage structure 11, a drive line through hole 13, a side groove 14, and a set screw hole 15. The rear structure 4 is located at the rear end of the robotic arm. The connecting chassis 41 is provided with three mounting holes 42, which can be used to connect and fix the robotic arm and the drive control system by bolts. The rest of the structure is the same as the main structure 1.

[0064] like Figure 7 As shown, each pair of main structural members 1 is connected by a flexible nickel-titanium rod 2, with its two ends inserted into the flexible rod slot 16, and then fastened from three directions by three set screws through the set threaded holes 15; the flexible rod is made of nickel-titanium alloy, which is a shape memory metal and has good resilience, ensuring soft deformation while improving the rigidity of the robot.

[0065] like Figure 8 As shown, when the three-ball-pin flexible continuum robot unit works with the robot, the drive line applies force, causing the main robot structure 1 to rotate under pressure, and the flexible nickel-titanium rod 2 to deform under pressure. A joint is formed between every two main structures 1, and each joint has two degrees of freedom, allowing rotation in any direction, making it flexible and versatile. At the same time, due to the rigid joint formed by the ball cage structure 11 and the ball pin structure 12, it can resist large torsional loads. Figure 8 It is a state in which the entire robotic arm bends and deforms.

[0066] In one embodiment, the three-ball pin type flexible continuum robot unit includes a main structure 1, a flexible nickel-titanium rod 2, a front end structure 3, and a rear end structure 4. Several main structures 1 are connected in pairs to form the entire robotic arm. A joint is formed between every two main structures 1. Each joint has two degrees of freedom and can rotate in any direction. Multiple drive lines pass through the drive line through hole 13 in sequence to drive the bending deformation of the continuum robot.

[0067] When the drive line is pulled, each unit block is compressed, and the entire continuous robotic arm bends and deforms. The flexible nickel-titanium rod 2 is compressed and deformed. It is a shape memory alloy with excellent springback ability, forming a flexible joint. At the same time, the ball joint of the ball pin structure 12 moves in the track groove of the ball cage structure 11 to adapt to the deformation of the robotic arm. The two are in a wrapping relationship and are clearance fit, forming a rigid joint.

[0068] The ball joint structure is placed inside the ball cage. When torsion occurs, the ball joint contacts the inner wall of the ball cage to limit and resist torsion, thereby greatly improving its torsional resistance. At the same time, when adjacent units bend, the adjacent structures contact each other to form the maximum bending angle, thereby preventing excessive load from damaging the flexible joint and improving the load-bearing capacity.

[0069] In one embodiment, the three-ball pin type flexible continuum robot unit includes:

[0070] Main structure 1, which is the main structure of the entire continuum robot and constitutes the entire robotic arm;

[0071] A flexible nickel-titanium rod 2, with its two ends connected to two adjacent main structural bodies 1 respectively;

[0072] Front-end structure 3 is located at the very front of the robotic arm;

[0073] The rear structure 4 is located at the very rear of the robotic arm.

[0074] Further, the main structure 1 includes a ball cage structure 11, a ball pin structure 12, a drive line through hole 13, a side groove 14, and a set screw hole 15; the ball cage structure 11 is located on the upper part of the main structure 1 and is a ball cage groove opened on the upper surface of the main structure 1; the ball pin structure 12 is disposed on the lower surface of the main structure 1; the drive line through hole 13 is disposed around the ball cage structure 11 and penetrates the entire main structure 1; the side groove 14 and the set screw hole 15 are alternately disposed on the side surface of the main structure 1. The flexible nickel-titanium rod 2 is disposed between two adjacent main structures 1 and connected by a flexible rod hole groove 16 and a set screw in the set screw hole 15. The front end structure 3 includes a central thread hole 31, a ball pin structure 12, a drive line through hole 13, a side groove 14, and a set screw hole 15; the central thread hole 31 is disposed at the center of the front end structure 3 and arranged at the foremost end of the robotic arm, and can be connected to tools such as cameras and searchlights. The rear structure 4 includes a connecting chassis 41, mounting holes 42, a ball cage structure 11, a drive line through hole 13, a side groove 14, and a set thread hole 15. The rear structure 4 is located at the rear end of the robotic arm. The connecting chassis 41 is provided with three mounting holes 42, which can be used to connect and fix the robotic arm and the drive control system by bolts.

[0075] In one embodiment, the ball pin structure 12 has three ball joints fixed to the lower surface of the main structure 1, placed in the ball cage structure 11 of the adjacent main structure 1, forming an enclosing relationship with a clearance fit, thus forming a rigid joint. Several main structures 1 are connected in pairs to form the entire robotic arm, and every two main structures 1 are connected by a flexible rod to form a flexible joint; multiple drive lines pass through the drive line through holes 13 in sequence, forming a rigid-flexible coupled single-core column continuous robot.

[0076] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not restrict the application from being implemented using the specific details described above.

[0077] The above description has been provided for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although several embodiments have been discussed above, those skilled in the art will recognize, through the teachings of this specification and without departing from the scope of the claims, various variations, modifications, additions, and sub-combinations thereof, all of which fall within the scope of protection of this invention.

Claims

1. A three-ball-bearing flexible continuum robotic unit, characterized by, It comprises, a plurality of main structural bodies which are connected in series with each other to form a mechanical arm, the main structural bodies comprising, a first structural body comprising three ball cage grooves arranged in a recessed manner along a central axis from an upper surface, the three ball cage grooves being in communication and being distributed in a central symmetrical manner with respect to the central axis to form a first ball cage structure, a first flexible rod hole groove penetrating through the first structural body along the central axis, a plurality of first driving wire through holes arranged around the first ball cage structure and penetrating through the entire first structural body, a first ball pin structure comprising three ball pins arranged on a lower surface of the first structural body, the first ball pin structure being clamped and limited by a ball cage structure of an upper adjacent structural body, a plurality of first side grooves recessed inwardly from side surfaces of the first structural body in a direction perpendicular to the central axis, a plurality of first set screw holes arranged on the side surfaces of the first structural body between adjacent first side grooves and in communication with the first flexible rod hole groove; a front end structural body arranged at a front end of the mechanical arm, the front end structural body comprising, a second structural body comprising a central threaded hole extending along a central axis from an upper surface, a second flexible rod hole groove penetrating through the second structural body along the central axis, a plurality of second driving wire through holes arranged around a peripheral edge of the second structural body and penetrating through the entire second structural body, a second ball pin structure comprising three ball pins arranged on a lower surface of the second structural body, a plurality of second side grooves recessed inwardly from side surfaces of the second structural body in a direction perpendicular to the central axis, a plurality of second set screw holes arranged on the side surfaces of the second structural body between adjacent second side grooves and in communication with the second flexible rod hole groove; a rear end structural body arranged at a rear end of the mechanical arm, the rear end structural body comprising, a third structural body comprising three ball cage grooves arranged in a recessed manner along a central axis from an upper surface, the three ball cage grooves being in communication and being distributed in a central symmetrical manner with respect to the central axis to form a second ball cage structure, a third flexible rod hole groove penetrating through the third structural body along the central axis, a plurality of third driving wire through holes arranged around the second ball cage structure and penetrating through the entire third structural body, a plurality of third side grooves recessed inwardly from side surfaces of the third structural body in a direction perpendicular to the central axis, a plurality of third set screw holes arranged on the side surfaces of the third structural body between adjacent third side grooves and in communication with the third flexible rod hole groove, a connecting base plate arranged at a bottom of the third structural body of the rear end structural body, a plurality of mounting fixing holes being distributed around a peripheral edge of the connecting base plate; a plurality of flexible nickel-titanium rods penetrating through the first, second, and third flexible rod hole grooves of the first, second, and third structural bodies and being connected via set screws in the first, second, and third set screw holes.

2. The three-ball-spline flexible continuum robotic unit of claim 1, wherein, The first, second, and third structural bodies are cylindrical structures.

3. The three-ball-spline flexible continuum robotic unit of claim 1, wherein, The front end structural body is threadedly connected to an operating instrument via the central threaded hole.

4. The three-ball-spline flexible continuum robotic unit of claim 3, wherein, The operating instrument comprises a camera or a searchlight.

5. The three-ball bushing flexible continuum robotic unit of claim 1, wherein, The rear end structural body is fixedly connected to a driving control system via the mounting fixing holes.

6. The three-ball bushing flexible continuum robotic unit of claim 1, wherein, The first and second ball pin structures and the first and second ball cage structures cooperatively have two degrees of freedom of rotation.

7. A continuum robot, characterized in that, It includes the three-ball-pin type flexible continuum robot unit as claimed in any one of claims 1-6, wherein a plurality of drive wires are connected in series through the first, second, and third drive wire through holes of the front end structure body, the main structure body, and the rear end structure body to form a continuum robot.

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