A micro continuum manipulator and a helical line acquisition method thereof

Abstract

The application discloses a micro continuum mechanical arm in the field of micro mechanical technology and a helical line acquisition method thereof, and aims to solve the problem that high compliance and high rigidity cannot be considered in the prior art. The arm body can well adapt to the driving force and expected continuous deformation when other components send a driving action or force to bend the whole mechanical arm, and the compliance and rigidity can be considered under the premise of a small arm radius; the transmission of the shaft arm action can be effectively transmitted through the force transmission type contact between the first helical belt and the second helical belt, and the basis of high rigidity is met; the shaft arm action makes the transmission contact points between the helical belts have a tendency to slip, and the anti-slip structure further arranged can avoid the mutual slipping between the helical belts, greatly reduces the propagation loss of the shaft arm action along the curved arm body, and then the high compliance and high rigidity can be considered under the premise of a small arm radius.

Description

Technical Field

[0001] This invention relates to a miniature continuous robotic arm and a method for obtaining its helix, belonging to the field of micromechanical technology. Background Technology

[0002] In cutting-edge applications such as natural cavity surgery and in-situ maintenance of aircraft engines, the working passage is often limited to less than 6mm.

[0003] Miniature robotic arms are commonly used in the industry for operations within confined spaces. Existing miniature robotic arms typically possess two characteristics: Firstly, their low stiffness inevitably leads to significant end-effector deformation when performing highly interactive tasks such as delicate suturing, tissue dissection, or blade repair, severely limiting the system's load-bearing capacity and positioning accuracy. Secondly, increasing the stiffness of a portion of the miniature robotic arm results in a decrease in compliance. Thirdly, the inherent high compliance of miniature robotic arms is crucial for their application in cutting-edge fields such as natural cavity surgery and in-situ maintenance of aero-engines. However, by reducing the diameter while maintaining high stiffness, existing miniature robotic arms are gradually losing the high compliance characteristic essential for achieving flexible navigation.

[0004] In summary, existing micro-robotic arms cannot simultaneously address the issues of high compliance and high rigidity. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a micro continuum manipulator and its helix acquisition method that take into account the advantages of high compliance and high stiffness.

[0006] To achieve the above objectives, this application employs the following technical solution:

[0007] In a first aspect, this application provides a miniature continuous robotic arm, comprising:

[0008] The bending arm includes at least a first spiral belt and a second spiral belt, both arranged around the arm axis. The first spiral belt and the second spiral belt have multiple force-transmitting contacts. The first spiral belt and the second spiral belt are also provided with anti-slip structures. The anti-slip structures can prevent slippage between the first spiral belt and the second spiral belt.

[0009] Furthermore, the anti-slip structure includes multiple pairs of matching buckles and slots; one of each pair of buckles and slots is located on the first spiral belt, and the other is located on the second spiral belt;

[0010] The buckle and the slot engage with each other to prevent slippage between the first spiral belt and the second spiral belt.

[0011] Furthermore, a first gap of a predetermined width is reserved between the buckle and the slot; when the bent arm is subjected to a force along the arm axis, the buckle passes through the first gap and engages with the slot.

[0012] Furthermore, both the first spiral ribbon and the second spiral ribbon have a friction-enhancing layer on their surfaces, the friction-enhancing layer comprising a friction-increasing material layer and / or a serrated surface.

[0013] Furthermore, it also includes a cable mounting tube, which is fitted into the curved arm body; multiple cable grooves are formed inside or on the surface of the cable mounting tube, the cable grooves are used to install cables, and the multiple cables are used for antagonistic control of the micro continuous robotic arm.

[0014] Furthermore, a second gap is reserved between the cable groove and the cable, and the smaller the distance between the cable groove and the curved arm, the wider the corresponding second gap.

[0015] Furthermore, the two ends of the curved arm are respectively fixedly connected to the cable fixing component and the support base, and a third gap of a set width is maintained between the two ends of the cable mounting tube and the cable fixing component and the support base.

[0016] Secondly, this application also provides a method for obtaining a helix for the micro continuum robot described in the first aspect, comprising:

[0017] The number of spiral bands in the curved arm and the spacing between the spirals are set to obtain the outer diameter of the curved arm.

[0018] Obtain the constraints, and set the periodic variation function based on the constraints;

[0019] The spiral is generated using the following formula:

[0020] ,

[0021] In the formula, The coordinate axes are parallel to the arm axis. and Perpendicular to The coordinate axes of the axis, For the progress parameters of the helix, The outer diameter of the curved arm. It is a periodically changing function. This is a periodic variation function obtained based on the number of spiral bands. The number of spiral bands, The distance between the spirals. As one embodiment, the outer diameter of the curved arm body... It was determined first based on the application scenario.

[0022] Furthermore, all the spiral bands have the same helix, and the constraints include: A) the periodic variation function is a bounded periodic function with all maxima equal and all minima equal; B) the maxima and minima of the periodic variation function alternate, and the phase interval between adjacent maxima and minima is [missing information]. C. The derivative of the periodic function at any extreme point is 0 and continuously differentiable;

[0023] Alternatively, at least one spiral band has a helix that differs from the helixes of all the other spiral bands, wherein the constraints include: A) the periodic function corresponding to any spiral band is a bounded periodic function with all maxima equal and all minima equal; B) the maxima and minima of the periodic function corresponding to any spiral band alternate, and the phase interval between adjacent maxima and minima is [missing information]. C. The derivative of the periodic function corresponding to any spiral is 0 at any extreme point and is continuously differentiable; D. The maxima and minima of the periodic functions corresponding to all spirals are the same, ensuring uniform structural amplitude; E. The sequence of occurrence of the maxima and minima of the periodic functions corresponding to all spirals is the same; F. The initial phases of the periodic functions corresponding to each spiral are successively different. .

[0024] Furthermore, the peak-to-peak value of the periodic variation function is:

[0025] ,

[0026] In the formula, The width of the spiral band. The minimum value for reserving the first gap between the buckle and the slot.

[0027] Compared with the prior art, the beneficial effects achieved by this application are as follows:

[0028] When the miniature continuous robotic arm provided in this application is used, due to the inherent elasticity of the spiral belt, when other components exert a driving force to bend the entire robotic arm, the bent arm can adapt well to the driving force and undergo the expected continuous deformation, balancing compliance and stiffness with a very small arm radius. Because there are multiple force transmission contacts between the first and second spiral belts, the arm movement can be effectively transmitted, satisfying the basic requirement of high stiffness. The arm movement causes the force transmission contact points between the spiral belts to tend to slip, but the further designed anti-slip structure can prevent the spiral belts from slipping against each other, greatly reducing the propagation loss of the arm movement along the bent arm, thus balancing high compliance and high stiffness with a very small arm radius. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the miniature continuous robotic arm provided in the embodiments of this application;

[0031] Figure 2 yes Figure 1 Axial section view;

[0032] Figure 3 yes Figure 1 A schematic diagram of the structure of the curved arm and its helix;

[0033] Figure 4 yes Do not take the front projection and three-dimensional view of the spiral body corresponding to times 2, 3, and 4;

[0034] Figure 5 yes Figure 1 A comparison diagram of friction-increasing and anti-slip schemes between adjacent spiral bands;

[0035] Figure 6 yes Figure 1 Cross-sectional diagrams of cable installation conduits for different schemes;

[0036] Figure 7 This is a flowchart of the spiral line acquisition method provided in the embodiments of this application;

[0037] Figure 8 yes Figure 1 A schematic diagram of the structure of a micro-scale continuous robotic arm during bending.

[0038] In the diagram: 1. Curved arm; 11. Helical body; 12. End; 13. Helix; 111. First helical band; 112. Second helical band; 114. Anti-slip structure;

[0039] 2. Cable installation conduit; 2.1. Cable tray; 2.2. Third gap; 2.3. Functional wire harness tray;

[0040] 3. Cables;

[0041] 4. Cable fasteners; 5. Support brackets;

[0042] 131. Buckle; 132. Slot; 1331. Resistance-enhancing material layer; 1332. Serrated surface. Detailed Implementation

[0043] The technical solutions of this application / the embodiments thereof will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application / the embodiments thereof, and not all embodiments thereof. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application / the application thereof or its application or use.

[0044] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0045] Example 1:

[0046] This embodiment provides a miniature continuous robotic arm to solve the problem that high compliance and high stiffness cannot be achieved simultaneously in the prior art.

[0047] refer to Figure 1 , Figure 2 and Figure 3 The main structure of the micro continuous robotic arm provided in this embodiment is a curved arm body 1. The curved arm body 1 is composed of at least a first spiral band 111 and a second spiral band 112. Those skilled in the art can adjust the number of spiral bands as needed. All of these spiral bands need to be arranged around the arm axis of the curved arm body 1.

[0048] by Figure 3 Taking the first helical strip 111 and the second helical strip 112 as an example, the first helical strip 111 and the second helical strip 112 are neither separated from each other nor completely attached to each other, but rather have multiple local contacts, or discrete contacts. Specifically, the first helical strip 111 and the second helical strip 112 have multiple force-transmitting contacts. Due to the force transmission between the first helical strip 111 and the second helical strip 112, in order to prevent slippage, the first helical strip 111 and the second helical strip 112 are also provided with anti-slip structures 114, which can prevent slippage between the first helical strip 111 and the second helical strip 112.

[0049] When the miniature continuous robotic arm provided in this embodiment is used, due to the inherent elasticity of the spiral belt, when other components exert a driving force to bend the entire robotic arm, the bending arm 1 can adapt well to the driving force and undergo the expected continuous deformation, balancing compliance and stiffness under the premise of a very small arm radius; since there are multiple force transmission contacts between the first spiral belt 111 and the second spiral belt 112, the shaft arm movement can be effectively transmitted, satisfying the basic requirement of high stiffness; the shaft arm movement causes the force transmission contact points between the spiral belts to tend to slip, and the further provided anti-slip structure 114 can prevent the spiral belts from slipping against each other, greatly reducing the propagation loss of the shaft arm movement along the bending arm 1, thus simultaneously balancing high compliance and high stiffness under the premise of a very small arm radius.

[0050] In this embodiment, the arm movement includes at least forward and backward movement along the arm axis, turning of the robotic arm, and twisting with the arm axis as the center of rotation.

[0051] Example 2:

[0052] This embodiment provides a miniature continuous robotic arm. This embodiment is an optimization based on Embodiment 1 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 1.

[0053] To further overcome the tendency for the spiral belts to slip during shaft arm movement, and also to reduce assembly difficulty. (Reference) Figure 3 The anti-slip structure 114 includes multiple pairs of matching buckles 131 and slots 132; one of each pair of buckles 131 and slots 132 is located on the first spiral belt 111 and the other is located on the second spiral belt 112; the buckles 131 and slots 132 engage with each other to prevent slippage between the first spiral belt 111 and the second spiral belt 112.

[0054] The matching buckle 131 and slot 132 structure can reduce the difficulty of assembly and disassembly. The buckle 131 and slot 132 that interlock in the assembled micro continuous robotic arm can prevent the adjacent spiral belts from slipping under the action of the arm movement.

[0055] To further reduce the difficulty of loading and unloading, a first gap of a set width is reserved between the buckle 131 and the slot 132; when the bent arm 1 is subjected to a force along the arm axis, the buckle 131 passes through the first gap and engages with the slot 132. Before use, a force that compresses and bends the arm 1 is applied along the arm axis to engage the buckle 131 and the slot 132; after use, a force that stretches and bends the arm 1 is applied along the arm axis to disengage the buckle 131 and the slot 132.

[0056] As one embodiment, to further prevent slippage between the first spiral band 111 and the second spiral band 112, and in conjunction with the operation of the buckle 131 and the slot 132 structure, refer to... Figure 5 The surfaces of the first spiral belt 111 and the second spiral belt 112 are provided with a friction reinforcement layer, which includes a friction-increasing material layer 1331 and / or a serrated surface 1332. Figure 5 The paper provides three options for friction reinforcement layers: Option (a) involves slotting and applying a friction-enhancing material layer 1331 only at the force transmission contact point of the spiral belt; Option (b) involves applying the friction-enhancing material layer 1331 directly on both the upper and lower sides of the spiral belt; Option (c) involves machining a serrated surface 1332 only at the force transmission contact point of the spiral belt; The friction-enhancing material layer 1331 is made of rubber or a friction-enhancing coating.

[0057] Example 3:

[0058] This embodiment provides a miniature continuous robotic arm. This embodiment is an optimization based on Embodiment 2 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 2.

[0059] This embodiment mainly discloses the power source for the axis arm movement of the micro continuous robot arm.

[0060] As one embodiment, reference Figure 1 and Figure 6 The micro continuous robotic arm also includes a cable mounting tube 2, which is fitted into the curved arm body 1; multiple cable grooves 2.1 are opened inside or on the surface of the cable mounting tube 2, which are used to install cables 3, and the multiple cables 3 are used for antagonistic control of the micro continuous robotic arm.

[0061] by Figure 6 For example, two pairs of cables 3 are laid in four directions, and each pair of cables 3 satisfies the antagonistic control in its direction.

[0062] As one embodiment, considering that although moving the cable 3 away from the arm axis can increase the torque, it will also cause greater deformation and displacement when the bending arm 1 bends, refer to Figure 6 A second gap is reserved between cable tray 2.1 and cable 3, for comparison. Figure 6 (a) and situation Figure 6 In (b), the smaller the distance between the cable groove 2.1 and the curved arm 1, the wider the corresponding second gap. A wider second gap satisfies the position and deformation of the cable 3 at the corner.

[0063] As one embodiment, this embodiment also discloses the head and tail structure of the micro-continuous robotic arm, referring to... Figure 1 and Figure 2The two ends 12 of the bending arm 1 are fixedly connected to the cable fixing component 4 and the support base 5, respectively. Alternatively, all the spiral bands of the cable fixing component 4 and the support base 5 are connected together, thus making the originally independent spiral bands a single integrated structure of the bending arm 1. When the bending arm 1 bends, it effectively transmits the arm's movement between itself and the cable fixing component 4 and the support base 5. To prevent the cable mounting tube 2 from being squeezed by the cable fixing component 4 and the support base 5, a third gap 2.2 of a set width is maintained between both ends of the cable mounting tube 2 and the cable fixing component 4 and the support base 5, respectively. When the bending arm 1 bends, both ends of the cable mounting tube 2 can be positioned within the third gap 2.2, avoiding collision and squeezing with the cable fixing component 4 and the support base 5. It is worth noting that... Figure 2 Only one third gap 2.2 on the side of support base 5 is shown; the third gap 2.2 on the side of cable fastener 4 cannot be directly accessed due to structural issues. Figure 2 It is shown in the middle.

[0064] As one embodiment, reference Figure 1 and Figure 6 A functional wire harness slot 2.3 is provided at or near the center of the cable installation pipe 2. The functional wire harness slot 2.3 is used to place the functional wire harness, which includes the steel wire for controlling the scalpel, signal lines, power lines, etc.

[0065] The micro-continuous robotic arm provided in this embodiment utilizes local discrete geometric restraint to significantly suppress axial instability and relative slippage of the skeleton under high antagonistic tension from the bottom layer of the configuration. This breaks through the technical bottleneck of the limited load-bearing capacity of conventional flexible skeletons, achieves a significant enhancement of macroscopic equivalent stiffness, and thus improves the load-bearing capacity of the robotic arm.

[0066] Example 4

[0067] This embodiment provides a miniature continuous robotic arm. This embodiment is an optimization based on Embodiment 3 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 3.

[0068] Miniature continuous robotic arms, such as Figure 1 As shown, the robotic arm consists of a curved arm body 1, a cable mounting tube 2, a cable 3, a cable fixing component 4, and a support base 5. Taking its application in the medical field as an example, the proximal end refers to the end closer to the operator, that is, the end near the patient's body; the distal end refers to the end farther from the operator, that is, the end closer to the lesion. The distal end of the robotic arm is the cable fixing component 4, which is fixedly connected to an end effector (not shown in the picture). The end effector can be an endoscope camera, an electrosurgical unit, a non-invasive grasping forceps, surgical scissors, etc. The proximal end of the robotic arm is the support base 5, which has holes through which the cable 3 passes. Figure 1In the diagram, the end where the support base 5 is located is the proximal end of the curved arm 1 of the robotic arm, and the opposite end, where the cable fixing piece 4 is located, is the distal end. (See reference...) Figure 1 Multiple parallel arrows, support base 5 and cable 3 are connected to the drive structure at the near end; (Refer to...) Figure 1 The single arrowhead, cable fixing piece 4, and cable 3 connect to the end effector at the distal end. The proximal end of support base 5 is fixedly connected to the robot system (not shown in the image), which is connected to the robot's drive system via a flexible or rigid long shaft, or directly to the control system. The proximal end of cable 3 is connected to the power components of the robot's drive system (not shown in the image), such as a linear motor module, a hydraulically driven slider, or a motor-driven pulley. The robot system can control multiple cables 3 to push to the distal end and pull to the proximal end. Figure 1 The number of cables 3 shown is 4, which can be increased or decreased as needed. By controlling the push / pull stroke of each cable 3, the bending amplitude of the robotic arm can be controlled, thereby controlling the spatial pose of the robot's end effector.

[0069] refer to Figure 2 The proximal end of the curved arm 1 is fixedly connected to the support base 5, and its distal end is fixedly connected to the cable fixing member 4. The cable mounting tube 2 is placed in its inner cavity. The cable 3 passes through the cable groove of the cable mounting tube 2. In this embodiment, the cable mounting tube 2 is an open-circuit multi-cavity tube, so the cable 3 will also come into contact with the inner wall of the curved arm 1. The cable mounting tube 2 will also bend as the cable 3 is pushed / pulled, so an appropriate second gap needs to be left between it and the proximal end of the cable fixing member 4 and the distal end of the support base 5. The distal end of the cable 3 is fixedly connected to the cable fixing member 4. The cable fixing member 4 and the support base 5 have through holes for placing cables used to control the end effector to achieve its function.

[0070] The basic structure of the curved arm 1 is as follows: Figure 3 As shown. It has a one-piece structure, and its main features include a spiral body 11, an end 12, and a helix 13. The spiral body 11 is a helical strip of uniform width and thickness. Figure 3The illustrated embodiment is a double-helix structure. Therefore, the helical body 11 includes a first helical strip 111 and a second helical strip 112, both identical in shape and distributed at 180° intervals along the longitudinal direction. A spiral line representing the shape is extracted from a single helical strip; this is the result of superimposing a conventional spiral line with a periodically changing curve. The spiral line 13 has equidistant, periodically arranged, and smoothly transitioning latches 131 and slots 132. The latches 131 of the first helical strip 111 approach each other, and vice versa, thus the bending arm 1 can resist axial compression. A gap exists between the latches 131 and slots 132 of adjacent helical strips. This gap is to account for the kerf width required for laser cutting; for femtosecond lasers, it is 10-20 μm, while conventional laser cutting is approximately 100 μm. When the continuous robotic arm is subjected to a basic preload, this gap is eliminated, at which point the structure can better resist axial compression, thus improving operational rigidity through antagonistic drives.

[0071] To further improve the operational rigidity of the snake-bone structure, a layer of friction-enhancing material 1331 can be provided in the contact area of ​​each pair of latches 131 and slots 132 to prevent relative slippage of the contact surfaces, such as... Figure 5 As shown, relative slippage relaxes the antagonistic tension, which reduces the working stiffness of the robotic arm and consequently its load-bearing capacity. Figure 5 (a) The embodiment shown in the figure has a material with high resistance, such as rubber, placed at a local position in the intended contact area of ​​each pair of buckles 131 and slots 132 on the spiral body 11. The implementation method can be to first make a notch in the intended contact area of ​​the buckles 131 and slots 132 by laser cutting, and then fill it with rubber material; or to directly add a coating with high resistance to the local contact area. Figure 5 (b) The embodiment shown has a material with high resistance on the upper and lower surfaces of each spiral body 11. Space can be reserved for this material during laser cutting, and then a layer of resistance-enhancing material 1331 can be added. Figure 5 (c) The embodiment shown has a serrated surface 1332 in the intended contact area of ​​the buckle 131 and the slot 132, which can be achieved by laser cutting. In addition to fine teeth, the serrated surface 1332 can also have other features, such as bumps, knurling, or other microscopic uneven features, as long as the goal of increasing surface roughness can be achieved.

[0072] Figure 1 and Figure 2 The cable mounting tube 2 in the illustrated embodiment uses a multi-cavity tube design, and its cross-sectional view is shown below. Figure 6 As shown in (a). The multi-cavity tubular cable tray 2.1 of the cable mounting tube 2 can be... Figure 6(a) shows an open structure that, together with the inner wall of the curved arm 1, forms a closed channel through which the cable 3 passes. Besides this open structure, the cable tray 2.1 scheme can also employ... Figure 6 (b) shows a structure with its own closed channel. The cable mounting conduit 2 is made of a relatively soft and flexible material. Besides the multi-cavity conduit design, the cable mounting conduit 2 can also be designed with a built-in cable mounting conduit 2 inside the curved arm 1, meaning the conduit used to make the curved arm 1 is itself a multi-cavity conduit, such as... Figure 6 As shown in (c), the special design structure of this application is then processed on it to realize the function.

[0073] Furthermore, the main structure of the robotic arm is a single piece, which can be integrally formed through laser cutting or 3D printing, effectively reducing the difficulty and cost of manufacturing and assembly. If laser cutting is chosen, the proposed solution has low process requirements, requiring only a two-axis laser cutting machine. It also has low precision requirements; based on a tube with an outer diameter of 3 mm and a wall thickness of 0.25 mm, the reference processing accuracy is ±0.05 mm, which can be achieved using ordinary economical laser processing equipment. In addition, to relax the process requirements, the gap between the latch 131 and the slot 132 can be further enlarged. During operation, applying an initial preload will bring the latch 131 and the slot 132 into contact, thereby enabling the robotic arm to resist axial compression and prevent slippage, thus enhancing its operational rigidity.

[0074] Example 5:

[0075] This embodiment provides a method for obtaining a helix, applicable to obtaining the helix 13 of the helical strip of the micro-continuous robotic arm in embodiments one to four. Furthermore, this method is applicable not only to the case where the helical body 11 contains only the first helical strip 111 and the second helical strip 112, but also to the case where the helical body 11 contains two or more helical strips.

[0076] refer to Figure 7 First, according to the design requirements of the micro continuous body robot, the number of spiral strips in the curved arm body 1 and the spacing between the spirals are set, and the outer diameter of the curved arm body 1 is obtained; the constraint conditions are obtained, and the periodic variation function is set according to the constraint conditions.

[0077] Helix 13 is generated using the following formula:

[0078] ,

[0079] In the formula, The coordinate axes are parallel to the arm axis. and Perpendicular to The coordinate axes of the axis, For the progress parameters of the helix, The outer diameter of the curved arm. It is a periodically changing function. This is a periodic variation function obtained based on the number of spiral bands. The number of spiral bands, The distance between the spirals. As one embodiment, the outer diameter of the curved arm body... It was determined first based on the application scenario, and then based on the outer diameter of the curved arm. Determine the number of spiral strips The spacing between the spirals Periodic variation function .

[0080] As one embodiment, reference Figure 3 The spacing between the spirals can be considered as the axial spacing of one spiral cycle.

[0081] The periodic variation function used in spiral 13 , can be adopted Other periodic functions can also be used, such as , Alternatively, functions that satisfy the conditions can be constructed by segmenting them.

[0082] As one embodiment, if all the spiral bands have the same helix 13, such as Figure 3 The first spiral band 111 and the second spiral band 112 in the diagram require the following simultaneous constraints: A) The periodic variation function is a bounded periodic function with all maxima equal and all minima equal; B) The maxima and minima of the periodic variation function alternate, and the phase interval between adjacent maxima and minima is [value missing]. Period; C. The derivative of a periodic function is 0 at any extreme point and is continuously differentiable. Figure 3 The image shows the spiral body 11 and the spiral line 13 of the second spiral band 112 in the spiral body 11.

[0083] As one embodiment, if there are differences between the various spiral bands, the simultaneous constraints include: A) the periodic variation function corresponding to any spiral is a bounded periodic function with all maxima equal and all minima equal; B) the maxima and minima of the periodic variation function corresponding to any spiral alternate, and the phase interval between adjacent maxima and minima is... C. The derivative of the periodic function corresponding to any spiral is 0 at any extreme point and is continuously differentiable; D. The maxima and minima of the periodic functions corresponding to all spirals are the same, ensuring uniform structural amplitude; E. The sequence of occurrence of the maxima and minima of the periodic functions corresponding to all spirals is the same; F. The initial phases of the periodic functions corresponding to each spiral are successively different. .

[0084] As one embodiment, all spirals 13 should follow the following: the peak-to-peak value of their periodic variation function is:

[0085] ,

[0086] In the formula, The width of the spiral band. The minimum value for reserving the first gap between the buckle and the slot.

[0087] Peak-to-peak value refers to the difference between the maximum and minimum values ​​of a bounded function, or the total height difference from the top to the bottom of the waveform, or the difference between the peak value and the valley value.

[0088] This embodiment can be achieved by changing the number of spiral strips. The spacing between the spirals Spiral width To adjust the working stiffness of the continuous body robotic arm. With the bending section length remaining constant, according to finite element simulation results, the general trend is... The larger the value, the smaller the bending stiffness and the larger the torsional stiffness; The larger the value, the greater the bending stiffness and the greater the torsional stiffness. The larger the value, the smaller the bending stiffness and the smaller the torsional stiffness. However, the effects of these three factors on bending stiffness and torsional stiffness are strongly coupled.

[0089] when =3.0 mm, =0.5 mm, =0.03 mm, , Take 1.8, 2.7, and 3.6 mm respectively. Taking 2, 3, and 4 respectively, the structures of the three are as follows: Figure 4 As shown in (a) and (b), (a) and (b) are the frontal projection and the three-dimensional view, respectively. When n takes the values ​​of 2, 3, and 4, the single spiral strips are distributed at equal intervals of 180°, 120°, and 90° along the circumference, that is, the angular spacing between the spiral strips is 360° / .

[0090] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0091] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "located in," "equipped with," "located in," "installed," "set," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. "Hinged connection" includes "rotational connection."

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A miniature continuous robotic arm, characterized in that, include: The curved arm (1) includes at least a first spiral belt (111) and a second spiral belt (112) both arranged around the arm axis. The first spiral belt (111) and the second spiral belt (112) make force-transmitting contact at multiple points. The first spiral belt (111) and the second spiral belt (112) are also provided with anti-slip structures (114). The anti-slip structures (114) can prevent slippage between the first spiral belt (111) and the second spiral belt (112). The anti-slip structure (114) includes multiple pairs of matching buckles (131) and slots (132); one of each pair of buckles (131) and slots (132) is located on the first spiral belt (111), and the other is located on the second spiral belt (112). The buckle (131) and the slot (132) engage with each other to prevent slippage between the first spiral band (111) and the second spiral band (112); A first gap of a set width is reserved between the buckle (131) and the slot (132); when the bent arm (1) is subjected to a force along the arm axis, the buckle (131) passes through the first gap and engages with the slot (132); The surfaces of the first spiral strip (111) and the second spiral strip (112) are provided with friction reinforcement layers, the friction reinforcement layers include a friction-increasing material layer (1331) and / or a serrated surface (1332); the method for obtaining the spiral of the robotic arm includes setting the number of spiral strips in the curved arm body (1) and the spacing between the spirals, and obtaining the outer diameter of the curved arm body (1); Obtain the constraints, and set the periodic variation function based on the constraints; At least one spiral band has a helix that is different from the helixes of all the other spiral bands. The constraint conditions include: A. The periodic variation function corresponding to any spiral band is a bounded periodic function with all maxima equal and all minima equal. B. The maxima and minima of the periodic function corresponding to any spiral alternate, and the phase interval between adjacent maxima and minima is... C. The derivative of the periodic function corresponding to any spiral is 0 at any extreme point and is continuously differentiable; D. The maxima and minima of the periodic functions corresponding to all spirals are the same, ensuring uniform structural amplitude; E. The sequence of occurrence of the maxima and minima of the periodic functions corresponding to all spirals is the same; F. The initial phases of the periodic functions corresponding to each spiral are successively different. .

2. The micro-continuous robotic arm according to claim 1, characterized in that, It also includes a cable mounting tube (2), which is fitted into the curved arm body (1); multiple cable grooves (2.1) are opened inside or on the surface of the cable mounting tube (2), and the cable grooves (2.1) are used to install cables (3), and the multiple cables (3) are used to perform antagonistic control on the micro continuous robot arm.

3. The micro-continuous robotic arm according to claim 2, characterized in that, A second gap is reserved between the cable groove (2.1) and the cable (3). The smaller the distance between the cable groove (2.1) and the curved arm (1), the wider the corresponding second gap.

4. The micro-continuous robotic arm according to claim 2, characterized in that, The two ends of the curved arm (1) are fixedly connected to the cable fixing component (4) and the support base (5) respectively. The two ends (12) of the cable mounting tube (2) are respectively separated from the cable fixing component (4) and the support base (5) by a third gap (2.2) of a set width.

5. The micro-continuous robotic arm according to claim 1, characterized in that, The spiral is generated by the following formula: ； In the formula, The coordinate axes are parallel to the arm axis. and Perpendicular to The coordinate axes of the axis, For the progress parameters of the helix, The outer diameter of the curved arm. It is a periodically changing function. This is a periodic variation function obtained based on the number of spiral bands. The number of spiral bands, The distance between the spirals.

6. The micro-continuous robotic arm according to claim 5, characterized in that, The peak-to-peak value of the periodic variation function is: ， In the formula, The width of the spiral band. The minimum value for reserving the first gap between the buckle and the slot.

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