A machine joint and a flexible machine arm

Abstract

The present invention relates to a machine joint, wherein a connector is fixed on the top surface; baffles are connected to the edges of the left and right sides, and grooves are provided on the baffles; a threaded hole is provided on the front side, and grooves are provided outside the threaded hole; a connector is fixed on the bottom surface, and a threading hole is designed. The present invention also relates to a flexible robot arm, comprising a base, a plurality of machine joints and an end mechanism connected in sequence, the base is designed with grooves, the end mechanism is designed with connecting parts to connect the machine joints, and the machine joints are connected by SMA wires and tension springs. The machine joint and flexible robot arm designed by the present invention can solve the problems of the robot arm being heavy due to the superposition of multiple sets of motors and metal gear parts, which is not conducive to flexible deployment and portable application; the problem that the metal gears generate large mechanical noise when running, which is not suitable for application scenarios that are sensitive to environmental noise; and the problem that the motor and gear combination structure is large in size and has many components, resulting in high maintenance costs and failure rates.

Description

Technical Field

[0001] The present invention relates to the field of memory alloy drive technology, and in particular to a machine joint and a flexible machine arm. Background Art

[0002] In the existing technology, multi-joint robotic arms usually use rigid transmission parts such as motors and gears to drive joint movement. Taking a three-degree-of-freedom joint as an example, three sets of motors and corresponding gears, couplings and other transmission parts are often required. Due to the superposition of multiple sets of motors and metal gear parts, the weight of the whole machine increases, which is not conducive to flexible deployment and portable application; metal gears generate large mechanical noise when running, which is not suitable for application scenarios that are sensitive to environmental noise; the combined structure of motors and gears is large in size and has many components, and the maintenance cost and failure rate are high.

[0003] Therefore, the existing technology has defects and needs to be improved and developed. Summary of the Invention

[0004] An embodiment of the invention provides a machine joint, which is used to solve the problems in the prior art that multi-joint robot arms usually use rigid transmission parts such as motors and gears to drive joint movement, and often require motors and corresponding gears, couplings and other transmission parts. Due to the superposition of multiple sets of motors and metal gear parts, the weight of the whole machine increases, which is not conducive to flexible deployment and portable applications; the metal gears generate large mechanical noise during operation and are not suitable for application scenarios that are sensitive to environmental noise; the motor and gear combination structure has large size and many components, and has high maintenance costs and failure rates.

[0005] According to a first aspect of an embodiment of the present invention, a machine joint is provided, wherein the surface of the main body facing upward when not powered is defined as the top surface, the main body is provided with a first threading tube passing through the top and bottom surfaces of the main body; a connector for detachably connecting a tension spring is fixed to one edge of the top surface; the side surface of the main body close to the connector is defined as the rear side surface, and a baffle is detachably connected to each of the edges of the top surface close to the left and right sides, the top of the baffle has a first curved surface, and a first groove is provided on the surface of the baffle close to the top surface; three threaded holes with the same hole center height are provided on the front side surface of the main body, and except for the middle threaded hole, the other threaded holes are provided with U-shaped grooves for accommodating SMA wires; the connector is also fixed to the edge of the bottom surface close to the rear side surface; the bottom surface has two downwardly protruding first bumps, each of which is away from A cylinder is fixed on the surface of the first threading tube, and the outer contour of the cylinder is adapted to the inner contour of the first groove; the left side and the right side are concave with a second curved surface facing the top surface, the axes of the two cylinders are collinear and perpendicular to the left side of the main body, the vertex of each cylinder is located below the second curved surface, and the curvature radius of the second curved surface is greater than the curvature radius of the first curved surface; a guide block is detachably connected to the surface of each first protrusion close to the first threading tube, and a third curved surface is concave on the surface of each first protrusion facing the guide block, and a fourth curved surface is concave on the surface of the guide block facing the connected first protrusion. When the guide block is detachably connected to the first protrusion, the fourth curved surface is spliced with the third curved surface to form a second threading tube, one end of the second threading tube is close to the first threading tube, and the other end of the second threading tube is close to the front side.

[0006] Furthermore, the connecting member has at least two second protrusions protruding upward, and each of the second protrusions is provided with a first connecting hole passing through the second protrusion. When the connecting member is detachably connected to the tension spring, a pin is installed in the first connecting hole. The center of each first connecting hole is located on the same axis, and the axis is perpendicular to the left side of the main body; a connecting groove is sandwiched between adjacent second protrusions, and when the connecting member is detachably connected to the tension spring, the hook of the tension spring is located in the connecting groove and is sleeved on the pin.

[0007] Furthermore, when the number of the second protrusions is greater than 2, the spacings between adjacent second protrusions are the same, and the tension springs detachably connected to the pins are parallel to each other.

[0008] Furthermore, the main body, the connecting member, the baffle, the first protrusion, the guide block, and the pin are made of insulating materials, and the insulating material includes at least one of aluminum alloy with oxidation treatment and polytetrafluoroethylene plastic.

[0009] According to a second aspect of an embodiment of the present invention, a flexible robotic arm is provided, comprising, in sequence, a detachably connected base, a plurality of robotic joints, and an end mechanism, wherein the robotic joints between the base and the end mechanism are defined as a first joint, a second joint, ..., an Nth joint, where N is a natural number not less than 4;

[0010] The base is concave in shape, and is provided with a first threading tube passing through the base. The two ends of the base protruding upward are defined as convex parts. The top of the convex part has a fifth curved surface, and the curvature radius of the fifth curved surface is not greater than the curvature radius of the second curved surface. The second groove is concave on the surface of each convex part close to the first threading tube. When the base is detachably connected to the first joint, each second groove of the base is externally mounted on each cylinder of the first joint.

[0011] The end mechanism has a connecting portion, and when the end mechanism is detachably connected to the Nth joint, the connecting portion is clamped between the two first grooves of the first joint;

[0012] Among the adjacent machine joints, the connecting piece of one of the machine joints located on the bottom surface of the main body is connected to the connecting piece of another machine joint located on the top surface of the main body through the tension spring; the flexible robot arm also includes a winding auxiliary block, and the winding auxiliary block is provided with three threaded holes with the same hole center height that pass through the winding auxiliary block, and the spacing of the threaded holes on the winding auxiliary block is the same as the spacing of the threaded holes on the main body; the two surfaces where the threaded holes pass through the winding auxiliary block are defined as the first surface and the second surface, and the first surface is excluding the center The U-shaped groove is formed on the outside of the threaded hole in the middle of the second surface, and the U-shaped groove is formed on the outside of the other threaded holes. The U-shaped groove on the first surface is opposite to the notch direction of the U-shaped groove on the second surface, and the notch direction of the V-shaped groove is the same as the notch direction of the U-shaped groove on the second surface; the front side of the main body of each machine joint is detachably connected to the winding auxiliary block by bolts, and for any k=1,2,…,N, the front side of the (N+1-k)th joint is attached to the first side of the winding auxiliary block , a fastening block is attached to the other surface of the winding auxiliary block with the threaded hole, a threaded hole is opened in the center of the fastening block and penetrates the fastening block, a bolt passes through the fastening block and the winding auxiliary block in sequence and is threadedly connected to the main body, and the surface attached to the fastening block is defined as the bonding surface, and the number of fastening blocks attached to the bonding surface of the winding auxiliary block corresponding to the (N+1-k)th joint is , each of the fastening blocks is attached to the surface of the winding auxiliary block and is concave with a winding groove. When the number of the fastening blocks is 3, the fastening blocks include a first fastening block, a second fastening block and a first fastening block in sequence, in the direction from the left side of the main body to the right side of the main body, the winding groove of the first fastening block and the winding groove of the second fastening block are downward, the winding groove of the first fastening block is the U-shaped groove, and the winding groove of the second fastening block is the V-shaped groove; when the number of the fastening blocks is 2, in the direction from the left side of the main body to the right side of the main body, the fastening blocks are 2 first fastening blocks, the winding groove of the first fastening block is upward, one of the first fastening blocks is close to the left side of the main body, and the other first fastening block is close to the right side of the main body;

[0013] The flexible robotic arm further includes N-1 insulated SMA wires, which shrink in length when energized. One SMA wire is wound around each of the Nth joint to the second joint. The main body defines a second threading tube through which the SMA wire passes from near the first threading tube to far away from the first threading tube as an inlet hole, and a second threading tube through which the SMA wire passes from far away from the first threading tube to near the first threading tube as an outlet hole.

[0014] When N is an even number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the t-th joint, the inlet hole of the t-th joint, the right notch of the U-shaped groove of the first fastening block on the left of the t-th joint, the left notch of the U-shaped groove of the first fastening block on the left of the t-th joint, the right notch of the U-shaped groove of the first fastening block on the left of the t-1-th joint, the left notch of the V-shaped groove of the second fastening block on the t-th joint, the right notch of the V-shaped groove of the second fastening block on the t-th joint, the the left notch of the U-shaped groove of the first fastening block to the right of the t-1 joint, the right notch of the U-shaped groove of the first fastening block to the right of the t-1 joint, the right notch of the U-shaped groove of the first fastening block to the right of the t joint, the left notch of the U-shaped groove of the first fastening block to the right of the t joint, the exit hole of the t joint, the first threading tube from the t joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire outside the base connected to a power supply, wherein t is an even number not less than 2, and t-1 is the numerical serial number of the machine joint adjacent to the t joint below the t joint among the machine joints;

[0015] When N is an even number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the p-th joint, the inlet hole of the p-th joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the p-th joint, the left notch of the U-shaped groove on the left of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the p-1 joint, the left notch of the V-shaped groove of the winding auxiliary block of the p-th joint, the right notch of the V-shaped groove of the winding auxiliary block of the p-th joint, and the The left notch of the U-shaped groove on the right of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the p joint, the left notch of the U-shaped groove on the right of the winding auxiliary block of the p joint, the exit hole of the p joint, the first threading tube from the p joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire located outside the base are connected to a power supply, wherein p is an odd number not less than 2, and p-1 is the numerical serial number of the machine joint adjacent to the p joint below.

[0016] When N is an odd number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the mth joint, the inlet hole of the mth joint, the right notch of the U-shaped groove of the first fastening block on the left of the mth joint, the left notch of the U-shaped groove of the first fastening block on the left of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the left of the m-1th joint, the left notch of the V-shaped groove of the second fastening block on the mth joint, the right notch of the V-shaped groove of the second fastening block on the mth joint, the the left notch of the U-shaped groove of the first fastening block on the right of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the right of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the right of the m-th joint, the left notch of the U-shaped groove of the first fastening block on the right of the m-th joint, the exit hole of the m-th joint, the first threading tube from the m-th joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire outside the base connected to a power supply, wherein m is an odd number not less than 2, and m-1 is the numerical serial number of the machine joint adjacent to the m-th joint below the machine joint;

[0017] When N is an odd number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the qth joint, the inlet hole of the qth joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the qth joint, the left notch of the U-shaped groove on the left of the winding auxiliary block of the q-1th joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the q-1th joint, the left notch of the V-shaped groove of the winding auxiliary block of the qth joint, the right notch of the V-shaped groove of the winding auxiliary block of the qth joint, and the The left notch of the U-shaped groove on the right of the winding auxiliary block of the q-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the q-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the q joint, the left notch of the U-shaped groove on the right of the winding auxiliary block of the q joint, the exit hole of the q joint, the first threading tube from the q joint to the first joint, the first threading tube of the base to the outside of the base, the wires at both ends of the SMA wire outside the base are connected to the power supply, where q is an even number not less than 2, and q-1 is the numerical serial number of the machine joint adjacent to the bottom of the q joint in the machine joint.

[0018] Furthermore, the end mechanism is at least one of a mechanical claw, an adsorption-type end effector, and a special tool-type end effector.

[0019] Furthermore, the tension spring is a stainless steel tension spring.

[0020] Furthermore, the diameter of the SMA wire is not less than 0.3 mm.

[0021] Furthermore, the insulation treatment method of the SMA wire is one of coating the SMA wire with a polyurethane insulation layer and arranging a silicone tube on the outer surface of the SMA wire.

[0022] Beneficial effects:

[0023] As can be seen from the above technical solutions, the present invention provides a robot joint and a flexible robot arm, which are driven by SMA wire and exhibit richer and more specific beneficial effects in terms of lightness, quietness, flexibility and reliability, including:

[0024] 1. Reduced system weight: The main body and connecting parts of each joint are made of lightweight materials such as aluminum alloy (anodized) or polytetrafluoroethylene plastic, replacing traditional motors and metal gears. The mass of each joint is reduced, the weight of the entire flexible robot arm is reduced, and the load requirements for the base and host computer structure are reduced.

[0025] 2. Eliminated operating noise: The joint movement is completely dependent on the thermal deformation of the SMA wire and the reset of the tension spring, without the friction noise of rigid gear meshing.

[0026] 3. Improved maintenance efficiency: Guide blocks, tension springs, connectors, winding auxiliary blocks and fastening blocks are all detachable modules that can be quickly replaced using standard bolts or pins, shortening the on-site replacement time for worn parts and reducing downtime maintenance costs.

[0027] 4. Improved scalability: By selecting different numbers of machine management, utilizing the combination of the first and second threading tubes and the winding auxiliary block, single-joint bending can be achieved. By independently applying current to the SMA wire, the SMA wire contracts, enabling angle bending control of individual machine joints and achieving full freedom of movement for the entire flexible robotic arm. The design of U- and V-grooves ensures smooth, non-stop bending and extension of each joint, making it suitable for micro-manipulation applications.

[0028] 5. Optimized energy consumption and driving efficiency: The diameter of the SMA wire is selected to be ≥0.3 mm, which improves the conductivity and thermal response speed, reduces the energy consumption of a single drive, and does not consume additional mechanical energy when cooling and resetting after power failure. The SMA wire is insulated and can be controlled by PWM to achieve temperature control, thereby improving driving efficiency.

[0029] 6. Improved safety: All structural components and guide mechanisms are made of insulating materials, providing excellent electrical isolation to prevent SMA wire leakage or short circuits at high temperatures. The tension spring and SMA wire are designed to alternately load, allowing the spring to automatically return to its original position in the event of an unexpected power outage or overload, providing a "power-off reset" protection function.

[0030] 7. Improved end-of-line execution expansion capabilities: The mold end mechanism can be quickly replaced, and the connecting part's locking structure is compatible with the first groove, which improves the efficiency of multi-task scene switching. Combined with SMA wire drive, it can realize secondary processing control such as micro-vibration and force feedback of the end mechanism, expanding the end-of-line execution capabilities.

[0031] 8. Low cost and simple process: Compared with complex gearbox and motor systems, the SMA wire structure has a simple design and low processing cost; modular design and batch production make the flexible robotic arm easy to assemble, with high production efficiency, reducing manufacturing and inspection costs.

[0032] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, to the extent such concepts are not mutually inconsistent, can be considered to be part of the inventive subject matter of this disclosure.

[0033] The foregoing and other aspects, embodiments, and features of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as features and / or beneficial effects of the exemplary embodiments, will become apparent from the following description or through practice of specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are not drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0035] Figure 1 This is a structural explosion diagram of a machine joint in an embodiment of the present application.

[0036] Figure 2 This is a structural schematic diagram of a machine joint in an embodiment of the present application.

[0037] Figure 3 This is a schematic structural diagram of a flexible robotic arm when N=4 in an embodiment of the present application.

[0038] Figure 4 This is a right view of a flexible robotic arm when N=4 in an embodiment of the present application.

[0039] Figure 5 This is a front view of a flexible robotic arm when N=4 in an embodiment of the present application.

[0040] Figure 6 This is a schematic structural diagram of the first surface of the winding auxiliary block in an embodiment of the present application.

[0041] Figure 7 This is a schematic structural diagram of the second surface of the winding auxiliary block in an embodiment of the present application.

[0042] Figure 8 This is a force analysis diagram of the end mechanism and the Nth joint before and after the SMA wire of the Nth joint is energized in the embodiment of the present application.

[0043] Description of Figure Numbers:

[0044] 1. Main body; 101. First threading tube; 102. Threaded hole; 103. U-shaped groove; 2. Tension spring; 3. Connector; 301. Second protrusion; 4. Baffle; 401. First groove; 5. First protrusion; 501. Cylinder; 6. Guide block; 7. Base; 8. End mechanism; 9. Winding auxiliary block; 10. First fastening block; 11. Second fastening block; 12. SMA wire. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0046] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "a", "an" or "the" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0047] In the existing technology, multi-joint robotic arms usually use rigid transmission parts such as motors and gears to drive joint movement, which often requires motors and corresponding gears, couplings and other transmission parts. The superposition of multiple sets of motors and metal gear parts increases the weight of the entire machine, which is not conducive to flexible deployment and portable applications; metal gears generate large mechanical noise when running, which is not suitable for application scenarios that are sensitive to environmental noise; the combined structure of motors and gears is large in size and has many components, resulting in high maintenance costs and failure rates.

[0048] In view of this, an embodiment of the present invention provides a machine joint, referring to Figure 1~Figure 2, define the surface of the main body 1 that faces upward when it is not powered on as the top surface, the top surface is rectangular, and the main body 1 is provided with a first threading tube 101 that passes through the top and bottom surfaces of the main body 1; one edge of the top surface is fixed with a connector 3 for detachably connecting the tension spring 2; define the side of the main body 1 close to the connector 3 as the rear side, and the edges of the top surface close to the left and right sides are each detachably connected with a baffle 4, the top of the baffle 4 is higher than the top of the connector 3, the bottom of the baffle 4 is flush with the top surface, and the same screw thread is provided between the bottom of the baffle 4 and the top and bottom surfaces of the main body 1. The baffle 4 and the main body 1 are detachably connected by bolts. The top of the baffle 4 has a first curved surface, and the baffle 4 is provided with a first groove 401 on the surface close to the top surface. The front side of the main body 1 is provided with three threaded holes 102 with the same hole center height. Except for the middle threaded hole 102, the other threaded holes 102 are provided with U-shaped grooves 103 for accommodating the SMA wire 12. A connector 3 is also fixed on the edge of the bottom surface close to the rear side surface. The bottom surface has two downwardly protruding first protrusions 5, each of which is away from the first threading hole. A cylinder 501 is fixed on the surface of the tube 101, and the outer contour of the cylinder 501 is adapted to the inner contour of the first groove 401; the left side and the right side are concave with a second curved surface on the top surface, and the axes of the two cylinders 501 are collinear and perpendicular to the left side of the main body 1. The vertex of each cylinder 501 is located below the second curved surface, and the curvature radius of the second curved surface is greater than the curvature radius of the first curved surface; each first protrusion 5 is detachably connected to a guide block 6 on the surface close to the first threading tube 101, and the guide block 6 is detachably connected to the surface of the first protrusion 5 when it is detachably connected to the first protrusion 5. A threaded hole 102 is provided, and a threaded hole 102 of the same specification is provided on the first protrusion 5 and passes through the first protrusion 5. The guide block 6 is threadedly connected to the first protrusion 5 by a bolt. A third curved surface is concave on the surface of each first protrusion 5 facing the guide block 6, and a fourth curved surface is concave on the surface of the guide block 6 facing the connected first protrusion 5. When the guide block 6 is detachably connected to the first protrusion 5, the fourth curved surface is spliced with the third curved surface to form a second threading tube. One end of the second threading tube is close to the first threading tube 101, and the other end of the second threading tube is close to the front side.

[0049] The first protrusion 5 can be L-shaped or have other shapes. When the guide block 6 is bolted to the first protrusion 5, the guide block 6 fits into the first protrusion 5. The third curved surface and the fourth curved surface surround and form a second threading tube through which the SMA wire 12 can pass. The first threading tube 101 in the main body 1 provides the main entrance and exit channel for the SMA wire 12. The first threading tube 101 and the second threading tube guide the path of the SMA wire 12. The diameter of the first threading tube 101 is larger than that of the second threading tube, and the diameter of the second threading tube is larger than the diameter of the SMA wire 12. The opening of the first threading tube 101 on the top surface of the main body 1, the openings at both ends of the second threading tube, and the notch of the U-shaped groove 103 can be chamfered to prevent wear and damage to the SMA wire 12 during expansion and contraction.

[0050] In certain embodiments, reference Figure 1 The connecting member 3 has at least two second protrusions 301 protruding upward, and each second protrusion 301 is provided with a first connecting hole penetrating the second protrusion 301. When the connecting member 3 is detachably connected to the tension spring 2, a pin is installed in the first connecting hole. The center of each first connecting hole is located on the same axis, and the axis is perpendicular to the left side of the main body 1; a connecting groove is sandwiched between adjacent second protrusions 301. When the connecting member 3 is detachably connected to the tension spring 2, the hook of the tension spring 2 is located in the connecting groove and is sleeved on the pin.

[0051] Through the positioning of the pin, the connecting groove between the second protrusions 301 exposes the pin, and the pin cooperates with the hook of the tension spring 2 to ensure that the tension spring 2 provides the resetting force when the joint is relocated.

[0052] In certain embodiments, when the number of second protrusions 301 is greater than two, the spacing between adjacent second protrusions 301 is uniform, and the tension springs 2 detachably connected to the pins are parallel to each other. When the number of second protrusions 301 is greater than two, adjacent tension springs 2 are ensured to be parallel and uniformly spaced, improving joint reduction stiffness and reliability. By arranging the tension springs 2 at equal spacing, the forces acting on the tension springs 2 are symmetrical, preventing unilateral loading that could cause joint jamming.

[0053] In certain embodiments, the main body 1, connector 3, baffle 4, first protrusion 5, guide block 6, and pin are constructed from insulating materials, including at least one of an oxidized aluminum alloy and polytetrafluoroethylene (PTFE). The use of insulating materials in these components prevents short circuits in the SMA wire 12. Furthermore, the oxidized aluminum alloy or polytetrafluoroethylene (PTFE) exhibits wear resistance, thereby reducing wear on the machine joints and increasing their service life.

[0054] The embodiment of the present invention also provides a flexible robot arm based on a machine joint, referring to Figures 3 to 5 , comprising a detachably connected base 7, a plurality of machine joints and an end mechanism 8, wherein the machine joints between the base 7 and the end mechanism 8 are defined as a first joint, a second joint, ..., an Nth joint, where N is a natural number not less than 4;

[0055] The base 7 is concave in shape and is provided with a first threading tube 101 passing through the base 7. The two ends of the base 7 that protrude upward are defined as convex portions. The top of the convex portion has a fifth curved surface, and the curvature radius of the fifth curved surface is no greater than the curvature radius of the second curved surface. A second groove is formed inwardly on the surface of each convex portion close to the first threading tube 101. When the base 7 is detachably connected to the first joint, each second groove of the base 7 is externally mounted on each cylinder 501 of the first joint.

[0056] The end mechanism 8 has a connecting portion. When the end mechanism 8 is detachably connected to the Nth joint, the connecting portion is clamped between the two first grooves 401 of the Nth joint. The connecting portion can be cylindrical and fit into the first groove 401. The end mechanism 8 can rotate in the first groove 401. If the end mechanism 8 does not need to rotate, a groove can be extended downward in both first grooves 401, and a protruding structure matching the groove can be extended downward in the connecting portion. When the connecting portion is located between the two first grooves 401 and the protruding structure is located between the two grooves, the end mechanism 8 is limited. It is also possible to extend a groove downward in both first grooves 401 of all machine joints for mass production.

[0057] Among the adjacent machine joints, the connector 3 of one machine joint located on the bottom surface of the main body 1 is connected to the connector 3 of the other machine joint located on the top surface of the main body 1 through a tension spring 2; both ends of the tension spring 2 have a hook, for example, one of the hooks is sleeved on the pin of the connector 3 on the bottom surface of the main body 1 of one machine joint, and the other hook is sleeved on the pin of the connector 3 on the top surface of the main body 1 of the other machine joint; the flexible robot arm also includes a winding auxiliary block 9, which is provided with three threaded holes 102 with the same hole center height passing through the winding auxiliary block 9, and the spacing of the threaded holes 102 on the winding auxiliary block 9 is the same as the spacing of the threaded holes 102 on the main body 1; the two surfaces where the threaded holes 102 pass through the winding auxiliary block 9 are defined as the first surface and the second surface, with reference to Figure 6-Figure 7 , except for the threaded hole 102 in the middle of the first surface, the other threaded holes 102 are provided with a U-shaped groove 103, the threaded hole 102 in the middle of the second surface is provided with a V-shaped groove, and the other threaded holes 102 are provided with a U-shaped groove 103. The notch direction of the U-shaped groove 103 on the first surface is opposite to that of the U-shaped groove 103 on the second surface, and the notch direction of the V-shaped groove is the same as that of the U-shaped groove 103 on the second surface; the front side surface of the main body 1 of each machine joint is detachably connected to the winding auxiliary block 9 by bolts, and for any k=1,2,…,N, the front side surface of the (N+1-k)th joint is attached to the first side surface of the winding auxiliary block 9 .

[0058] For example, when N is 4, it means that there are 4 joints in the machine. In order to know which surface of the winding auxiliary block the front side of the second joint is attached to, it can be calculated. Knowing that the value of N is 4 and the value of (N+1-k) is 2, the value of k is calculated to be 3. In this case, k is an odd number, and the front side of the second joint is attached to the first surface of the winding auxiliary block. When N is 5, it means that there are 5 joints in the machine. In order to know which surface of the winding auxiliary block the front side of the second joint is attached to, it can be calculated. Knowing that the value of N is 5 and the value of (N+1-k) is 2, the value of k is calculated to be 4. In this case, k is an even number, and the front side of the second joint is attached to the second surface of the winding auxiliary block.

[0059] The other surface of the winding auxiliary block 9 with the threaded hole 102 is attached with a fastening block. The center of the fastening block is provided with a threaded hole 102 that penetrates the fastening block. The bolt passes through the fastening block and the winding auxiliary block 9 in sequence and is threadedly connected to the main body 1. The surface attached with the fastening block is defined as the fitting surface. The number of fastening blocks attached to the fitting surface of the winding auxiliary block 9 corresponding to the (N+1-k)th joint is .

[0060] For example, when N is 4, it means that there are 4 joints in the machine. In order to know the number of fastening blocks fitted on the fitting surface of the winding auxiliary block 9 corresponding to the second joint, it can be calculated. If the value of N is known to be 4 and the value of (N+1-k) is 2, then the value of k is calculated to be 3. At this time, k is an odd number, and the number of fastening blocks fitted on the fitting surface of the winding auxiliary block 9 corresponding to the second joint is 3. When N is 5, it means that there are 5 joints in the machine. In order to know the number of fastening blocks fitted on the fitting surface of the winding auxiliary block 9 corresponding to the second joint, it can be calculated. If the value of N is known to be 5 and the value of (N+1-k) is 2, then the value of k is calculated to be 4. At this time, k is an even number, and the number of fastening blocks fitted on the fitting surface of the winding auxiliary block 9 corresponding to the second joint is 2.

[0061] Each fastening block is attached to the surface of the winding auxiliary block 9 and is concave with a winding groove. When the number of fastening blocks is 3, the fastening blocks include a first fastening block 10, a second fastening block 11 and a first fastening block 10 in sequence, in the direction from the left side of the main body 1 to the right side of the main body 1. The winding groove of the first fastening block 10 and the winding groove of the second fastening block 11 are notched downward, the winding groove of the first fastening block 10 is a U-shaped groove 103, and the winding groove of the second fastening block 11 is a V-shaped groove; when the number of fastening blocks is 2, the fastening blocks are 2 first fastening blocks 10 in the direction from the left side of the main body 1 to the right side of the main body 1, and the winding groove of the first fastening block 10 is notched upward, one of the first fastening blocks 10 is close to the left side of the main body 1, and the other first fastening block 10 is close to the right side of the main body 1;

[0062] The flexible robotic arm further includes N-1 insulated SMA wires 12. When the SMA wires 12 are energized, the length of the SMA wires 12 shrinks. One SMA wire 12 is wound around each of the Nth joint to the second joint. The main body 1 defines a second threading tube through which the SMA wire 12 passes from near the first threading tube 101 to far away from the first threading tube 101 as an inlet hole, and a second threading tube through which the SMA wire 12 passes from far away from the first threading tube 101 to near the first threading tube 101 as an outlet hole.

[0063] When N is an even number, the SMA wire 12 passes through the first threading tube 101 of the base 7 from the outside of the base 7, the first threading tube 101 from the first joint to the t-th joint, the inlet hole of the t-th joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the left of the t-th joint, the left notch of the U-shaped groove 103 of the first fastening block 10 on the left of the t-1-th joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the left of the t-1-th joint, the left notch of the V-shaped groove of the second fastening block 11 on the t-th joint, the right notch of the V-shaped groove of the second fastening block 11 on the t-th joint, the left notch of the V-shaped groove of the second fastening block 11 on the t-th joint, the right notch of the V-shaped groove of the second fastening block 11 on the t-th joint, the left notch of the U-shaped groove of the first fastening block 10 on the left of the t-1 ... first fastening block 11 on the t-th joint, the left notch of the U-shaped groove of the first fastening block 10 on the left of the t-1-th joint, the left notch of the V-shaped groove of the second fastening block 11 on the The left notch of the U-shaped groove 103 of the first fastening block 10 to the right of the t-1 joint, the right notch of the U-shaped groove 103 of the first fastening block 10 to the right of the t-1 joint, the right notch of the U-shaped groove 103 of the first fastening block 10 to the right of the t joint, the left notch of the U-shaped groove 103 of the first fastening block 10 to the right of the t joint, the exit hole of the t joint, the first threading tube 101 from the t joint to the first joint, the first threading tube 101 of the base 7 to the outside of the base 7, and the wires at both ends of the SMA wire 12 outside the base 7 are connected to the power supply, wherein t is an even number not less than 2, and t-1 is the numerical serial number of the machine joint adjacent to the t joint below the t joint;

[0064] When N is an even number, the SMA wire 12 passes through the first threading tube 101 of the base 7 from the outside of the base 7, the first threading tube 101 from the first joint to the p-th joint, the inlet hole of the p-th joint, the right notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the p-th joint, the left notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the p-1 joint, the right notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the p-1 joint, the left notch of the V-shaped groove of the winding auxiliary block 9 of the p-th joint, the right notch of the V-shaped groove of the winding auxiliary block 9 of the p-th joint, and the left notch of the V-shaped groove of the winding auxiliary block 9 of the p-th joint. -1 joint, the left notch of the right U-shaped groove 103 of the winding auxiliary block 9, the right notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the p-1 joint, the right notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the p joint, the left notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the p joint, the exit hole of the p joint, the first threading tube 101 from the p joint to the first joint, the first threading tube 101 of the base 7 to the outside of the base 7, the wires at both ends of the SMA wire 12 outside the base 7 are connected to the power supply, wherein p is an odd number not less than 2, and p-1 is the numerical serial number of the machine joint adjacent to the p joint below.

[0065] When N is an odd number, the SMA wire 12 passes through the first threading tube 101 of the base 7 from the outside of the base 7, the first threading tube 101 from the first joint to the m-th joint, the inlet hole of the m-th joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the left of the m-th joint, the left notch of the U-shaped groove 103 of the first fastening block 10 on the left of the m-1-th joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the left of the m-1-th joint, the left notch of the V-shaped groove of the second fastening block 11 of the m-th joint, the right notch of the V-shaped groove of the second fastening block 11 of the m-th joint, the left notch of the V-shaped groove of the second fastening block 11 of the m-th joint, the right notch of the V-shaped groove of the first fastening block 11 of the m-th joint, the left notch of the U-shaped groove of the first fastening block 10 on the left of the m-1 ... left notch of the U-shaped groove of the first fastening block 10 on the left of the m-1-th joint, the left notch of the V-shaped groove of the second fastening block 11 of the m-th joint, the left notch of the U-shaped groove of the first fastening block 10 on the left of the m-1-th joint, the left notch of the the left notch of the U-shaped groove 103 of the first fastening block 10 on the right of the m-1 joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the right of the m-1 joint, the right notch of the U-shaped groove 103 of the first fastening block 10 on the right of the m joint, the left notch of the U-shaped groove 103 of the first fastening block 10 on the right of the m joint, the exit hole of the m joint, the first threading tube 101 from the m joint to the first joint, the first threading tube 101 of the base 7 to the outside of the base 7, and the wires at both ends of the SMA wire 12 outside the base 7 connected to the power supply, wherein m is an odd number not less than 2, and m-1 is the numerical serial number of the machine joint adjacent to the m joint below.

[0066] When N is an odd number, the SMA wire 12 passes through the first threading tube 101 of the base 7 from the outside of the base 7, the first threading tube 101 from the first joint to the qth joint, the inlet hole of the qth joint, the right notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the qth joint, the left notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the q-1th joint, the right notch of the left U-shaped groove 103 of the winding auxiliary block 9 of the q-1th joint, the left notch of the V-shaped groove of the winding auxiliary block 9 of the qth joint, the right notch of the V-shaped groove of the winding auxiliary block 9 of the qth joint, and the qth joint. -1 joint, the left notch of the right U-shaped groove 103 of the winding auxiliary block 9, the right notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the q-1 joint, the right notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the q joint, the left notch of the right U-shaped groove 103 of the winding auxiliary block 9 of the q joint, the exit hole of the q joint, the first threading tube 101 from the q joint to the first joint, the first threading tube 101 of the base 7 to the outside of the base 7, the wires at both ends of the SMA wire 12 outside the base 7 are connected to the power supply, where q is an even number not less than 2, and q-1 is the numerical serial number of the adjacent machine joint below the q joint in the machine joint.

[0067] Each SMA wire 12 is connected to a separate power source, enabling individual and segmented power supply. Using PWM control, the SMA wires 12 are energized in a specific sequence, driving the corresponding machine joints to rotate. The overall PWM system architecture can adopt a common architecture in the prior art. Each SMA wire 12 contracts when energized, and the contraction sequence drives the corresponding segmented joints to rotate.

[0068] The tension spring 2 provides preload when other joints are not driven, ensuring support and return during the action switching process. The U-shaped groove 103 and the V-shaped groove on the winding auxiliary block 9 are arranged alternately with notches of different angles and directions, so that the wire can generate the necessary storage length and force path when it folds back between the joints, achieving controlled bending without excessive friction or wire slippage. In addition, the grooves of the U-shaped groove 103 and the V-shaped groove can be designed to have a smooth transition to prevent wear of the SMA wire 12. The notches of the U-shaped groove 103 and the V-shaped groove can be designed with chamfers to prevent wear of the SMA wire 12.

[0069] In some embodiments, the end mechanism 8 is at least one of a mechanical gripper, a suction-type end effector, and a dedicated tool-type end effector. Dedicated tool-type end effectors include spot welding guns, laser welding heads, spray guns, and tool heads. A snap-fit connection allows for quick replacement of the end effector.

[0070] In some embodiments, the tension spring 2 is a stainless steel tension spring having a straight mechanical property curve and low wear. When the hooks of the multiple tension springs 2 are passed through, the single-point stress concentration of the hooks on the connector 3 is reduced, thereby extending the service life.

[0071] In certain embodiments, the diameter of the SMA wire 12 is no less than 0.3 mm.

[0072] In certain embodiments, the SMA wire 12 is insulated by coating the SMA wire 12 with a polyurethane insulation layer or by inserting a silicone tube over the SMA wire 12. The polyurethane coating, with a thickness within the range of 0.1-0.3 mm, prevents short circuits while minimizing heat conduction. The silicone tube, with an inner diameter slightly larger than the diameter of the SMA wire 12, creates a small air layer during heat dissipation, balancing insulation and heat dissipation requirements.

[0073] When the SMA wire 12 of the Nth joint is energized, the force analysis of the end mechanism 8 and the Nth joint is performed. Figure 8 As shown, Figure 8 The left side shows the force analysis of the terminal mechanism 8 without load in the power-off state, where "1" is added to the lower right corner of the corresponding physical quantity symbol; Figure 8 The right side shows the force analysis of the end mechanism 8 subjected to a force of 50 N after the SMA wire 12 of the Nth joint is energized. In this analysis, a "2" is added to the lower right corner of the corresponding physical quantity symbol; Indicates the support force between joints, Indicates the force of SMA wire 12 in martensitic state, Indicates the force of SMA wire 12 in austenitic state, Indicates the force on the terminal mechanism 8, Indicates the supporting force of tension spring 2, It represents the angle between the force and the vertical direction. After the SMA wire 12 of the Nth joint is energized, They are 22°, 8°, 13.27°, and 12.57° respectively:

[0074]

[0075]

[0076] in, Their respective meanings are: The force of the terminal mechanism 8 The moment arm; is the force of SMA wire 12 in martensitic state The moment arm; is the force of SMA wire 12 in austenitic state The lever arm. The measured lengths are 25.5mm, 10.6mm, and 16.6mm respectively; The value of is a known quantity obtained by measuring with strain gauges; It is a known quantity obtained by direct measurement with a dynamometer; It is a known quantity obtained by measurement such as laser rangefinder; It is a known quantity obtained by measurement such as an angle measuring instrument; and Belong to unknown quantity. In the embodiment of the present application, when the number of machine joints is 4, The value is 30.69; The value is about 12.58, and the stress of the single SMA wire 12 is calculated to be 3.5 Newtons through the force analysis formula.

[0077] The force analysis was performed on the Nth joint and the N-1th joint. The N-1th joint represents the machine joint below the Nth joint. When the SMA wire in the N-1th joint is energized, the supporting force between the machine joints is transferred from the Nth joint to the N-1th joint through force interaction. Using the same force analysis principle as above, the stress in the single SMA wire 12 was 3.2 N. Similarly, the stress in the remaining joints was analyzed, and the stress in the single SMA wire 12 was greater than 3 N.

[0078] Based on the above analysis, when using an SMA wire 12 with a diameter of 0.3 mm, the stress of a single SMA wire 12 is greater than 3 Newtons. Compared with the existing technology, the stress of a single SMA wire 12 is greater, and the application range of machine joints and flexible robot arms is wider, which is suitable for the application of robot arms in different environments.

[0079] In summary, the present invention provides a machine joint and a flexible robot arm, which are driven by SMA wire 12 and show richer and more specific beneficial effects in terms of lightweight, quietness, flexibility and reliability, including: reduced system weight: a single joint body 1 and a connector 3 are made of lightweight materials such as aluminum alloy (anodized) or polytetrafluoroethylene plastic, replacing traditional motors and metal gears, reducing the mass of a single joint, reducing the weight of the overall flexible robot arm, and reducing the load requirements on the base 7 and the upper computer structure. Eliminated operating noise: The joint movement is completely dependent on the thermal deformation of the SMA wire 12 and the reset of the tension spring 2, without rigid gear meshing friction noise. Improved maintenance efficiency: the guide block 6, tension spring 2, connector 3, winding auxiliary block 9 and fastening block are all detachable modules, which can be quickly replaced by standard bolts or pins, shortening the on-site replacement time of wear parts and reducing downtime maintenance costs. Improved scalability: By selecting different numbers of machine management, the combination of the first and second threading tubes and the winding auxiliary block 9 allows for single-joint bending. By independently applying current to the SMA wire 12, the wire 12 contracts, enabling angular bending control of individual machine joints and achieving freedom of movement for the entire flexible robotic arm. The design of the U-shaped and V-shaped grooves 103 ensures smooth, non-jerky bending and extension of each joint, making it suitable for micro-manipulation applications. Optimized energy consumption and drive efficiency: The SMA wire 12 is selected with a diameter ≥ 0.3 mm, which improves conductivity and thermal response speed, reduces single-actuation energy consumption, and eliminates additional mechanical energy consumption during cooling and reset after power failure. The SMA wire 12 is insulated and can be controlled using PWM for temperature control, further improving drive efficiency. Improved safety: All structural components and guide mechanisms are constructed of insulating materials, providing good electrical isolation to prevent leakage or short circuits in the SMA wire 12 at high temperatures. The tension spring 2 and the SMA wire 12 are designed to bear force alternately. In the event of an unexpected power outage or overload, the tension spring 2 can be used to restore the robot to its original position, providing a "power-off reset" protection function. The terminal execution expansion capability is improved: the mold terminal mechanism 8 can be quickly replaced, and the connecting part's snap-fit structure is compatible with the first groove 401 of the Nth joint, improving the efficiency of multi-task scene switching. Combined with the SMA wire 12 drive, secondary processing control such as micro-vibration and force feedback of the terminal mechanism 8 can be achieved, expanding the terminal execution capability. Low cost and simple process: Compared with complex gearboxes and motor systems, the SMA wire 12 structure has a simple design and low processing cost. Modular design and mass production make the flexible robotic arm easy to assemble, highly efficient, and reduce manufacturing and inspection costs.

[0080] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A machine joint, characterized in that: The top surface of the main body is defined as the top surface, and the main body is provided with a first threading tube that passes through the top and bottom surfaces of the main body; a connecting piece for detachably connecting a tension spring is fixed on one edge of the top surface; the side of the main body close to the connecting piece is defined as the rear side surface, and a baffle is detachably connected to the edges of the top surface close to the left and right sides, the top of the baffle has a first curved surface, and a first groove is provided on the surface of the baffle close to the top surface; three threaded holes with the same hole center height are provided on the front side surface of the main body, and except for the middle threaded hole, the other threaded holes are provided with U-shaped grooves for accommodating SMA wire; the connecting piece is also fixed on the edge of the bottom surface close to the rear side surface; the bottom surface has two downwardly protruding first protrusions, and each of the first protrusions is fixed on the surface away from the first threading tube There is a cylinder, the outer contour of the cylinder is adapted to the inner contour of the first groove; the left side and the right side are concave with a second curved surface facing the top surface, the axes of the two cylinders are collinear and perpendicular to the left side of the main body, the vertex of each cylinder is located below the second curved surface, and the curvature radius of the second curved surface is greater than the curvature radius of the first curved surface; each of the first protrusions is detachably connected to a guide block on the surface close to the first threading tube, and each of the first protrusions is concave with a third curved surface on the surface facing the guide block, and the guide block is concave with a fourth curved surface on the surface facing the connected first protrusion, when the guide block is detachably connected to the first protrusion, the fourth curved surface is spliced with the third curved surface to form a second threading tube, one end of the second threading tube is close to the first threading tube, and the other end of the second threading tube is close to the front side.

2. A machine joint according to claim 1, characterized in that: The connecting member has at least two second protrusions protruding upward, and each of the second protrusions is provided with a first connecting hole that passes through the second protrusion. When the connecting member is detachably connected to the tension spring, a pin is installed in the first connecting hole. The center of each first connecting hole is located on the same axis, and the axis is perpendicular to the left side of the main body; a connecting groove is sandwiched between adjacent second protrusions, and when the connecting member is detachably connected to the tension spring, the hook of the tension spring is located in the connecting groove and is sleeved on the pin.

3. A machine joint according to claim 2, characterized in that: When the number of the second protrusions is greater than 2, the intervals between adjacent second protrusions are the same, and the tension springs detachably connected to the pins are parallel to each other.

4. A machine joint according to claim 3, characterized in that: The main body, the connecting member, the baffle, the first protrusion, the guide block, and the pin are made of insulating materials, and the insulating material includes at least one of aluminum alloy with oxidation treatment and polytetrafluoroethylene plastic.

5. A flexible robotic arm based on the robotic joint of claim 3, characterized in that: The invention sequentially comprises a detachably connected base, a plurality of machine joints and an end mechanism, wherein the machine joints between the base and the end mechanism are defined as a first joint, a second joint, ..., an Nth joint, where N is a natural number not less than 4; The base is concave in shape, and is provided with a first threading tube passing through the base. The two ends of the base protruding upward are defined as convex parts. The top of the convex part has a fifth curved surface, and the curvature radius of the fifth curved surface is not greater than the curvature radius of the second curved surface. Each of the convex parts has a second groove on the surface close to the first threading tube. When the base is detachably connected to the first joint, each of the second grooves of the base is externally mounted on each of the cylinders of the first joint. The end mechanism has a connecting portion, and when the end mechanism is detachably connected to the Nth joint, the connecting portion is clamped between the two first grooves of the first joint; Among the adjacent machine joints, the connecting piece of one of the machine joints located on the bottom surface of the main body is connected to the connecting piece of another machine joint located on the top surface of the main body through the tension spring; the flexible robot arm also includes a winding auxiliary block, and the winding auxiliary block is provided with three threaded holes with the same hole center height that pass through the winding auxiliary block, and the spacing of the threaded holes on the winding auxiliary block is the same as the spacing of the threaded holes on the main body; the two surfaces where the threaded holes pass through the winding auxiliary block are defined as the first surface and the second surface, and the first surface is excluding the center The U-shaped groove is formed on the outside of the threaded hole in the middle of the second surface, and the U-shaped groove is formed on the outside of the other threaded holes. The U-shaped groove on the first surface is opposite to the notch direction of the U-shaped groove on the second surface, and the notch direction of the V-shaped groove is the same as the notch direction of the U-shaped groove on the second surface; the front side of the main body of each machine joint is detachably connected to the winding auxiliary block by bolts, and for any k=1,2,…,N, the front side of the (N+1-k)th joint is attached to the first side of the winding auxiliary block , a fastening block is attached to the other surface of the winding auxiliary block with the threaded hole, a threaded hole is opened in the center of the fastening block and penetrates the fastening block, a bolt passes through the fastening block and the winding auxiliary block in sequence and is threadedly connected to the main body, and the surface attached to the fastening block is defined as the bonding surface, and the number of fastening blocks attached to the bonding surface of the winding auxiliary block corresponding to the (N+1-k)th joint is , each of the fastening blocks is attached to the surface of the winding auxiliary block and is concave with a winding groove. When the number of the fastening blocks is 3, the fastening blocks include a first fastening block, a second fastening block and a first fastening block in sequence, in the direction from the left side of the main body to the right side of the main body, the winding groove of the first fastening block and the winding groove of the second fastening block are downward, the winding groove of the first fastening block is the U-shaped groove, and the winding groove of the second fastening block is the V-shaped groove; when the number of the fastening blocks is 2, in the direction from the left side of the main body to the right side of the main body, the fastening blocks are 2 first fastening blocks, the winding groove of the first fastening block is upward, one of the first fastening blocks is close to the left side of the main body, and the other first fastening block is close to the right side of the main body; The flexible robotic arm further includes N-1 insulated SMA wires, which shrink in length when energized. One SMA wire is wound around each of the Nth joint to the second joint. The main body defines a second threading tube through which the SMA wire passes from near the first threading tube to far away from the first threading tube as an inlet hole, and a second threading tube through which the SMA wire passes from far away from the first threading tube to near the first threading tube as an outlet hole. When N is an even number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the t-th joint, the inlet hole of the t-th joint, the right notch of the U-shaped groove of the first fastening block on the left of the t-th joint, the left notch of the U-shaped groove of the first fastening block on the left of the t-th joint, the right notch of the U-shaped groove of the first fastening block on the left of the t-1-th joint, the left notch of the V-shaped groove of the second fastening block on the t-th joint, the right notch of the V-shaped groove of the second fastening block on the t-th joint, the the left notch of the U-shaped groove of the first fastening block to the right of the t-1 joint, the right notch of the U-shaped groove of the first fastening block to the right of the t-1 joint, the right notch of the U-shaped groove of the first fastening block to the right of the t joint, the left notch of the U-shaped groove of the first fastening block to the right of the t joint, the exit hole of the t joint, the first threading tube from the t joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire outside the base connected to a power supply, wherein t is an even number not less than 2, and t-1 is the numerical serial number of the machine joint adjacent to the t joint below the t joint among the machine joints; When N is an even number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the p-th joint, the inlet hole of the p-th joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the p-th joint, the left notch of the U-shaped groove on the left of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the p-1 joint, the left notch of the V-shaped groove of the winding auxiliary block of the p-th joint, the right notch of the V-shaped groove of the winding auxiliary block of the p-th joint, and the The left notch of the U-shaped groove on the right of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the p-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the p joint, the left notch of the U-shaped groove on the right of the winding auxiliary block of the p joint, the exit hole of the p joint, the first threading tube from the p joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire located outside the base are connected to a power supply, wherein p is an odd number not less than 2, and p-1 is the numerical serial number of the machine joint adjacent to the p joint below. When N is an odd number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the mth joint, the inlet hole of the mth joint, the right notch of the U-shaped groove of the first fastening block on the left of the mth joint, the left notch of the U-shaped groove of the first fastening block on the left of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the left of the m-1th joint, the left notch of the V-shaped groove of the second fastening block on the mth joint, the right notch of the V-shaped groove of the second fastening block on the mth joint, the the left notch of the U-shaped groove of the first fastening block on the right of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the right of the m-1th joint, the right notch of the U-shaped groove of the first fastening block on the right of the m-th joint, the left notch of the U-shaped groove of the first fastening block on the right of the m-th joint, the exit hole of the m-th joint, the first threading tube from the m-th joint to the first joint, the first threading tube of the base to the outside of the base, and the wires at both ends of the SMA wire outside the base connected to a power supply, wherein m is an odd number not less than 2, and m-1 is the numerical serial number of the machine joint adjacent to the m-th joint below the machine joint; When N is an odd number, the SMA wire passes through the first threading tube of the base from the outside of the base, the first threading tube from the first joint to the qth joint, the inlet hole of the qth joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the qth joint, the left notch of the U-shaped groove on the left of the winding auxiliary block of the q-1th joint, the right notch of the U-shaped groove on the left of the winding auxiliary block of the q-1th joint, the left notch of the V-shaped groove of the winding auxiliary block of the qth joint, the right notch of the V-shaped groove of the winding auxiliary block of the qth joint, and the The left notch of the U-shaped groove on the right of the winding auxiliary block of the q-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the q-1 joint, the right notch of the U-shaped groove on the right of the winding auxiliary block of the q joint, the left notch of the U-shaped groove on the right of the winding auxiliary block of the q joint, the exit hole of the q joint, the first threading tube from the q joint to the first joint, the first threading tube of the base to the outside of the base, the wires at both ends of the SMA wire outside the base are connected to the power supply, where q is an even number not less than 2, and q-1 is the numerical serial number of the machine joint adjacent to the bottom of the q joint in the machine joint.

6. The flexible robotic arm according to claim 5, characterized in that: The end mechanism is at least one of a mechanical claw, an adsorption-type end effector, and a special tool-type end effector.

7. The flexible robotic arm according to claim 5, characterized in that: The tension spring is a stainless steel tension spring.

8. The flexible robotic arm according to claim 5, characterized in that: The diameter of the SMA wire is not less than 0.3 mm.

9. The flexible robotic arm according to claim 5, characterized in that: The insulation treatment method of the SMA wire is one of coating the SMA wire with a polyurethane insulation layer and arranging a silicone tube on the outer surface of the SMA wire.

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