A continuous robot arm and method of obtaining same

Abstract

This invention discloses a continuous robotic arm and its acquisition method in the field of micro-robotic arm technology, aiming to solve the problems of existing continuous robotic arms and their acquisition methods. It includes two helical bodies and their meshing structure. The two helical bodies can mesh with each other. Through the meshing action of the meshing structure, various motion requirements of the bending arm can be met, while providing good structural stiffness. This significantly suppresses axial instability and relative slippage of the skeleton under high antagonistic tension from the configuration level, thus breaking through the technical bottleneck of limited load-bearing capacity of conventional flexible skeletons and achieving a significant enhancement of macroscopic equivalent stiffness, thereby improving the load-bearing capacity of the robotic arm. The corresponding acquisition method fully considers that the meshing structure is the primary factor affecting the bending and motion capabilities of the continuous robotic arm. Therefore, the outer diameter of the robotic arm is taken as the primary design parameter, and the meshing structure design parameters are iteratively designed based on this parameter. This method is simple and clear, improving design efficiency.

Description

Technical Field

[0001] This invention relates to a continuous robotic arm and its acquisition method, belonging to the field of micro robotic arm technology. Background Technology

[0002] With the continuous evolution of precision manufacturing and intelligent control technologies, the demand for operations in narrow cavities is becoming increasingly urgent in fields such as industrial inspection and medical care.

[0003] In industrial inspection scenarios, non-destructive testing of the narrow internal cavities of core components such as aero-engine compressors, combustion chambers, and turbines represents a typical scenario for precise operations in confined spaces. Similarly, in the medical field, treatments performed through natural body cavities require the use of miniature flexible actuators for precise intracavitary operations, again highlighting the need for tools designed for confined spaces. These scenarios typically require robotic arms with an outer diameter of less than 4mm; however, as the outer diameter decreases, their load-bearing capacity also diminishes. Currently, they are primarily focused on light-load applications such as monitoring and diagnosis. For instance, in industrial settings, existing miniature flexible robotic arms struggle to repair faulty areas, while in medical settings, they are limited in performing surgical procedures such as traction, resection, and suturing of diseased tissue.

[0004] Therefore, existing continuous robotic arms have the problem of not being able to achieve high load-bearing capacity with a small outer diameter. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a continuous robotic arm with a relatively small design outer diameter that meets the requirements of high load-bearing capacity, and a method for obtaining the same.

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

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

[0008] The curved arm includes at least a first spiral and a second spiral, both arranged around the arm axis. The first spiral and the second spiral have multiple force-transmitting contacts, and the first spiral and the second spiral are also provided with meshing structures. When the curved arm is bent, the meshing structures of the first spiral and the meshing structures of the second spiral engage.

[0009] Furthermore, the meshing structure includes an arc-shaped meshing band, which includes alternating additive and subtractive portions; the arc-shaped meshing bands are respectively disposed on the first helical body or the second helical body, and are distributed along the helical direction of the first helical body or the second helical body; adjacent arc-shaped meshing bands along the arm axis mesh with each other.

[0010] Furthermore, the arc-shaped meshing band includes an additive portion and a subtractive portion alternately arranged according to a set pitch circle and around the center of the set pitch circle, so that when the curved arm body bends, the adjacent arc-shaped meshing bands along the arm axis engage in rolling contact.

[0011] Furthermore, the additive portion includes complete teeth and incomplete teeth located at the edge of the arcuate meshing band, the incomplete teeth also having a smooth transition between the portion of the helix where the arcuate meshing band is not provided via a transition surface.

[0012] Furthermore, it also includes a cable mounting component, which is fitted into the curved arm body; the cable mounting component has multiple cable grooves on its interior or surface, the cable grooves are used to install cables, and the multiple cables are used for antagonistic control of the continuous robotic arm;

[0013] Alternatively, the spiral body of the curved arm bends toward the arm axis to form a cable groove, which is used to install cables, and multiple cables are used for antagonistic control of the continuous robotic arm.

[0014] Furthermore, a second gap is reserved between the cable groove and the cable.

[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 component and the cable fixing component and the support base.

[0016] Secondly, this application also provides a method for acquiring the continuous robotic arm described in the first aspect, comprising:

[0017] The pitch of a single helix and the outer diameter of the robotic arm are set, and the generation formula of the single helix is ​​obtained based on the pitch of the single helix and the outer diameter of the robotic arm.

[0018] The number of spirals is set, and the interval angle between adjacent spirals is obtained based on the number of spirals.

[0019] Obtain the design parameters of the meshing structure; model the primary model based on the design parameters of the meshing structure, the generation formula of the single helix, and the interval angle between adjacent helices.

[0020] The maximum design bending angle is simulated on the primary model to obtain the conflict and overlap results of adjacent helices. In response to the conflict and overlap results indicating the existence of conflict, the meshing structure design parameters are updated until the conflict and overlap results indicate the absence of conflict, and the final model is output.

[0021] A continuous robotic arm is obtained based on the final model.

[0022] Furthermore, the meshing structure design parameters include: tooth profile module, number of teeth, and gear tilt control angle; obtain the pitch circles of two adjacent arc-shaped meshing zones along the arm shaft axis, draw the line connecting the centers of the two pitch circles, and obtain the angle difference between the line connecting the centers and the arm shaft axis to obtain the gear tilt control angle;

[0023] Based on the primary model, a Cartesian coordinate system is constructed with the arm axis centerline under no-force conditions. The coordinates of the starting segment center point of the spiral in the primary model are obtained, and the rotation angle of each segment of the spiral relative to the previous segment is set.

[0024] Based on the center point coordinates of the starting section and the unit rotation angle, the center point coordinates of each section of the spiral are estimated section by section. A bending arc is fitted based on the center point coordinates of all sections of the spiral. The external tangent connection angle of the bending arc is calculated. In response to the angle difference between the external tangent connection angle and the maximum design bending angle being greater than the error threshold, the gear tilt control angle is updated.

[0025] In response to the fact that the angle difference between the external tangent connection angle and the maximum design bending angle is not greater than the error threshold, the edge contour coordinates of each segment of the helical body are obtained. In response to the fact that the edge contour coordinates of any segment of the helical body are located within the contours of other segments, the output is a conflict overlap result with conflict; otherwise, the output is a conflict overlap result without conflict.

[0026] Furthermore, the step-by-step estimation of the center point coordinates of each segment of the helix includes:

[0027] The method of estimating the center point coordinates of each segment of the helix segment by segment includes:

[0028] Obtain the coordinates of the center point of a known segment of the helix;

[0029] The coordinates of the center point of the unknown segment of the helix after the known segment are obtained by calculating the following formula:

[0030] ,

[0031] In the formula, The coordinates of the center point of the unknown segment of the helix. Given the coordinates of the center point of a known segment of the helix, For coordinate change amount, For the tooth profile module, Number of teeth For gear tilt control angle, Let be the angle of revolution of the unknown segment of the helix relative to the known segment of the helix. The periodic pitch of a single helix. The number of spirochetes. The rotation angle of the unit;

[0032] In response to the gear tilt control angle and the revolution angle of the unknown segment of the helical body relative to the known segment of the helical body both being less than the corresponding threshold angle, the coordinates of the center point of the unknown segment of the helical body after the known segment are calculated using the following formula:

[0033] .

[0034] Compared with the prior art, the beneficial effects achieved by this application are as follows:

[0035] The continuous robotic arm provided in this application meets various motion requirements of the bending arm body through the meshing effect between the meshing structures, while providing good structural stiffness. It significantly suppresses axial instability and relative slippage of the skeleton under high antagonistic tension from the configuration level, thereby breaking through the technical bottleneck of the limited load-bearing capacity of conventional flexible skeletons and achieving a significant enhancement of macroscopic equivalent stiffness, thus improving the load-bearing capacity of the robotic arm. The corresponding acquisition method fully considers that the meshing structure is the primary factor affecting the bending and motion capabilities of the continuous robotic arm. Therefore, the outer diameter of the robotic arm is taken as the primary design parameter, and the meshing structure design parameters are iteratively designed based on it. This method is simple and clear, and improves design efficiency. Attached Figure Description

[0036] 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.

[0037] Figure 1 This is a schematic diagram of the continuous robotic arm provided in the embodiments of this application;

[0038] Figure 2 yes Figure 1 Axial section view;

[0039] Figure 3 yes Figure 1 Schematic diagram of the structure of the central helix body;

[0040] Figure 4 yes Figure 3 Schematic diagram of the interlocking structure;

[0041] Figure 5 According to Figure 1 A photo of the manufactured robotic arm sample when it is bent;

[0042] Figure 6 yes Figure 1A schematic diagram of the rotation of the unknown segment of the helix and its revolution around the known segment of the helix during a bend;

[0043] Figure 7 yes Figure 1 Cross-sectional schematic diagrams of three different types of cable trays;

[0044] Figure 8 yes Figure 7 A schematic diagram of the cable tray shown in case (c);

[0045] Figure 9 yes Figure 1 A schematic diagram of the contact area when adjacent arc-shaped meshing bands engage and roll;

[0046] Figure 10 From another perspective Figure 1 A schematic diagram of the contact area when adjacent arc-shaped meshing bands engage and roll;

[0047] Figure 11 yes Figure 1 Schematic diagram of edge treatment for the mid-arc meshing band;

[0048] Figure 12 This is a schematic diagram of the steps of the method for acquiring a continuous robotic arm provided in an embodiment of this application;

[0049] Figure 13 yes Figure 1 A schematic diagram illustrating the pitch of the helical coil;

[0050] Figure 14 yes Figure 1 A schematic diagram illustrating the pitch circle and its center;

[0051] Figure 15 yes Figure 1 A schematic diagram illustrating the fitting of the mid-arc line;

[0052] In the diagram: 1. Bending arm; 2. Cable mounting hardware; 3. Cable; 4. Cable fastener; 5. Support base;

[0053] 11. Helical body; 111. First helical body; 112. Second helical body;

[0054] 12. Meshing structure; 121. Additive part; 122. Subtractive part; 123. Pitch circle; 12.1. Arc-shaped meshing band; 121.1. Incomplete tooth; 121.2. Transition surface; 121.2.1. Axial cutting surface; 121.1.1. Planar cutting surface; 121.3. Complete tooth; 121.4. Adjacent area; 121.5. Contact area; 121.6. Original meshing band outline;

[0055] 13. End;

[0056] 2.1 Cable tray; 2.2 Third gap. Detailed Implementation

[0057] 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.

[0058] Example 1:

[0059] This embodiment provides a continuous robotic arm to solve the problem that existing technologies cannot provide high load-bearing capacity with a small outer diameter.

[0060] refer to Figures 1 to 4 The continuous robotic arm provided in this embodiment includes a bending arm body 1, which includes at least a first helical body 111 and a second helical body 112, both of which are arranged around the arm axis. The first helical body 111 and the second helical body 112 have multiple force-transmitting contacts. The first helical body 111 and the second helical body 112 are also provided with meshing structures 12 respectively. When the bending arm body 1 bends, the meshing structures 12 of the first helical body 111 and the meshing structures 12 of the second helical body 112 mesh with each other.

[0061] In one embodiment, the force-transmitting contact of the helices is achieved by the first helical body 111 and the second helical body 112 abutting against each other, and a friction-enhancing layer to prevent slippage is provided at the force-transmitting contact point. Considering that the meshing structure 12 can also serve as a force-transmitting contact point and a friction-enhancing layer, in this embodiment, the first helical body 111 and the second helical body 112 achieve force-transmitting contact through the meshing of the meshing structure 12.

[0062] refer to Figure 3 It is precisely because the meshing structure 12 between the first helix 111 and the second helix 112 meshes with each other that the deformation of the first helix 111 and the deformation of the second helix 112 are constrained by each other. When the bent arm 1 undergoes torsional action or axial load, the first helix 111 and the second helix 112 transmit the force to each other through the meshing point, thereby coupling the action and deformation of the two helices.

[0063] refer to Figure 1The distal and proximal ends of the curved arm 1 are respectively fixedly connected to a cable fixing component 4 and a support base 5. The cable fixing component 4 is used to connect to the end effector, such as surgical forceps, and the support base 5 is used to connect to the drive mechanism. When the curved arm 1 is subjected to the drive mechanism, the reaction force of the end effector, or other external forces from the working environment, due to the force transmission between the spirals, these forces and effects are distributed relatively evenly to each segment of each spiral, making the distributed forces and effects less than the yield strength of each segment of the spiral. Overall, the curved arm 1 has high rigidity. The bending arm 1 has a strong load-bearing capacity. However, when the bending arm 1 performs high-load-bearing operations, the first helical element 111 and the second helical element 112 tend to slip relative to each other. This slippage could lead to the disengagement of force transmission points between the helical elements, preventing the force and action from being distributed evenly across each section of the helical element during operation. The meshing constraint of the meshing structure 12 prevents relative slippage between the first helical element 111 and the second helical element 112, preventing overall structural deformation of the bending arm 1 and thus avoiding force unloading under large operational external forces. Therefore, we can conclude that the continuous robotic arm provided in this embodiment can maintain a certain level of operational rigidity while possessing adequate deformation capacity with a relatively small design outer diameter, meeting the requirements of various operational tasks. (Reference) Figure 5 As shown in the photograph, when the meshing constraint of the meshing structure 12 is present, the robotic arm sample can distribute the bending arc and stress to each section when bending, and the arc of each part of the robotic arm tends to be consistent.

[0064] It is worth noting that the bending arm 1 only requires a minimum of two helices, namely the first helice 111 and the second helice 112, to achieve the corresponding function. Those skilled in the art can set more helices as needed and arrange them with reference to the relationship between the first helice 111 and the second helice 112.

[0065] In one embodiment, the force transmission point between the spirals is the contact point where the meshing structure 12 meshes and constrains each other.

[0066] Example 2:

[0067] This embodiment provides a 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.

[0068] As one embodiment, reference Figure 1 , Figure 3 and Figure 4 The meshing structure 12 can take the form of an arc-shaped meshing band 12.1, taking into account the bending operation of the curved boom 1, referring to Figure 4 Observe the details Figure 4From the movement trajectory between the first spiral 111 and the second spiral 112, we can see that the meshing structure 12 on the side of the first spiral 111 and the meshing structure 12 on the side of the second spiral 112 are making a tangential motion of an approximately circular arc. In order to match the bending action of the bending arm 1, the meshing structure 12 can be designed as an "arc" shape of the arc meshing band 12.1.

[0069] Further observation Figure 4 The arc-shaped meshing band 12.1 includes alternating additive portions 121 and subtractive portions 122; the arc-shaped meshing bands 12.1 are respectively disposed on the first helical body 111 or the second helical body 112, and are distributed along the helical direction of the first helical body 111 or the second helical body 112; adjacent arc-shaped meshing bands 12.1 along the arm shaft axis mesh with each other.

[0070] As one embodiment, the additive part 121 and the subtractive part 122 can be designed with reference to the teeth and grooves of a gear. Therefore, the "arc" shape of the arc meshing band 12.1 can be designed using the design steps of the pitch circle 123 used in gear design. The additive part 121 and the subtractive part 122 are alternately arranged around the center of the set pitch circle 123. When the bending arm 1 is in bending operation, refer to Figure 4 The change in the bending amplitude will cause meshing and rolling contact between the two arc-shaped meshing belts 12.1. Since the design of the arc-shaped meshing belt 12.1 adopts the pitch circle 123 in the gear design method, the meshing and rolling trajectory of the two arc-shaped meshing belts 12.1 basically follows their respective pitch circles 123.

[0071] When the bending arm 1 is to achieve no bending or the degree of bending reaches the design limit, the misalignment between the additive portion 121 and the subtractive portion 122 located at the edge of the arc-shaped meshing band 12.1 may hinder the aforementioned action. To avoid this phenomenon, as one embodiment, observation is conducted... Figure 11 The additive portion 121 includes complete teeth 121.3 and incomplete teeth 121.1 located at the edge of the arc-shaped meshing band 12.1. The incomplete teeth 121.1 also smoothly transition with the portion of the first helix 111 or the second helix 112 that does not have the arc-shaped meshing band 12.1 through the transition surface 121.2.

[0072] refer to Figure 11At the edge of the arc-shaped meshing band 12.1, a subtractive portion 122 and an additive portion 121 should originally be formed along the original meshing band contour 121.6. However, to avoid interfering with the operation of the curved arm 1, the subtractive portion 122 at the edge of the arc-shaped meshing band 12.1 is filled in, and the additive portion 121 is partially removed according to the planar cutting surface 121.1.1 to form an incomplete tooth 121.1. The portion of the first helical body 111 or the second helical body 112 without the arc-shaped meshing band 12.1 is referred to as the adjacent region 121.4. There was originally a subtractive portion 122 between the adjacent region 121.4 and the incomplete tooth 121.1, but to ensure the smooth operation of the curved arm 1, this subtractive portion 122 is filled in. The shape of the filled region is formed by the extension of the planar cutting surface 121.1.1 and the transition surface 121.2. As one embodiment, the transition surface 121.2 can be an axial cutting surface 121.2.1. The scanning rays of the axial cutting surface 121.2.1 are all perpendicular to the central rotation axis of the robotic arm. The axial cutting part is inclined. In other embodiments, it can also be vertical to achieve the connection from planar cutting to axial cutting, and to improve stress concentration by setting rounded corners.

[0073] Considering the excellent properties of the continuous robotic arm provided in this embodiment, antagonistic control is suitable. As one embodiment, refer to... Figure 1 , Figure 2 , Figure 7 and Figure 8 The continuous robotic arm also includes a cable mounting component 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 component 2, which are used to install cables 3, and the multiple cables 3 are used for antagonistic control of the continuous robotic arm.

[0074] refer to Figure 7 Cable trays 2.1 include at least three forms: ① Reference Figure 7 In case (a), the cable tray 2.1 is open, with the opening of the cable tray 2.1 facing outward relative to the arm shaft axis. This design facilitates the lateral installation and maintenance of the cable 3; ② Refer to Figure 7 Cases (b) and (d) Figure 7 The dashed arrow indicates that the cable installation component 2 in case (b) is shown separately in case (d). The cable trough 2.1 is semi-enclosed, with only its two ends connected to the outside world. There are no openings on its sides. This design is beneficial for the protection of cable 3.

[0075] In addition, there is a special cable tray 2.1 structure that does not require additional components specifically for setting up the cable tray 2.1. (See reference...) Figure 7 Case (c) and Figure 8The spiral body 11 of the curved arm 1 bends toward the arm axis to form a cable groove 2.1. The cable groove 2.1 is used to install cables 3. Multiple cables 3 are used for antagonistic control of the continuous robotic arm.

[0076] Considering that while moving cable 3 away from the arm axis can increase torque, it will also cause greater deformation and displacement when the bending arm 1 bends, as one embodiment, with Figure 7 Taking cases (a) and (b) as examples, a second gap is reserved between cable tray 2.1 and cable 3.

[0077] In one embodiment, the width of the second gap is inversely proportional to the distance between the cable groove 2.1 and the curved arm 1; the further the cable groove 2.1 is opened into the curved arm 1, the wider the second gap between the inner wall of the cable groove 2.1 and the cable 3, and the wider second gap satisfies the position and deformation of the cable 3 at the corner.

[0078] As one embodiment, reference Figure 2 The two ends 13 of the cable mounting component 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. The end located at the cable fixing component 4 is not shown. When the bending arm 1 bends, the deformed portions at both ends of the cable mounting tube 2 can be placed within the third gap 2.2 to avoid collision and compression with the cable fixing component 4 and the support base 5.

[0079] The continuous robotic arm provided in this embodiment meets the various motion requirements of the bending arm body 1 through the meshing action between the arc-shaped meshing bands 12.1. At the same time, it can provide better structural stiffness, significantly suppressing the axial instability and relative slippage of the skeleton under high antagonistic tension from the bottom of the configuration. This breaks through the technical bottleneck of the limited load-bearing capacity of conventional flexible skeletons, and achieves a significant enhancement of macroscopic equivalent stiffness, thereby improving the load-bearing capacity of the robotic arm.

[0080] Example 3

[0081] This embodiment provides a method for obtaining a continuous robotic arm, applicable to the generation of the helical body of the continuous robotic arm in Embodiments 1 and 2.

[0082] The method includes:

[0083] refer to Figure 13 Set the pitch of a single spiral. and the outer diameter of the robotic arm The generation formula for a single helix is ​​obtained based on the pitch of the single helix and the outer diameter of the robotic arm. As one embodiment, during experimental modeling and final modeling, the cross-sectional shape of the helix can be set, and a single helix can be generated by sweeping along the generation formula of the single helix at the same cross section.

[0084] The number of spirals is set, and the interval angle between adjacent spirals is obtained based on the number of spirals; the interval angle is also called the interval period; generally speaking, the interval angle is based on the number of spirals in the spiral body 11 in the design. Dividing the helix into 360° equal parts, for example, in Examples 1 and 2, the number of helices... The value is 2, and the interval angle is 180°;

[0085] Obtain the meshing structure design parameters; model the initial model based on the meshing structure design parameters, the generation formula of a single helix, and the interval angle between adjacent helices; among them, the meshing structure design parameters are used to construct the meshing structure 12, and the cross-sectional shape of the helix can be set. A single helix is ​​generated by sweeping along the single helix generation formula with a uniform cross-section, based on the number of helices in the helical body 11 in the design. The interval angle is obtained by dividing 360° equally. The interval between each spiral body is adjusted according to the interval angle, thereby determining the shape of the spiral body 11 and the continuous robotic arm.

[0086] The maximum design bending angle is simulated on the primary model to obtain the conflict and overlap results of adjacent helices. In response to the conflict and overlap results indicating the existence of conflict, the meshing structure design parameters are updated until the conflict and overlap results indicate the absence of conflict, and the final model is output.

[0087] The final model is used for manufacturing to obtain a continuous robotic arm as mentioned in Example 1 or 2.

[0088] This acquisition method, or design method, fully considers that the meshing structure 12 is the primary factor affecting the bending and motion capabilities of the continuous robotic arm. Therefore, the outer diameter of the robotic arm is used as the basis for the design. The primary design parameter is used as the design background for iterative design of the meshing structure design parameters. This method is simple and clear, and improves design efficiency. The continuous robotic arm designed according to this method has the same technical effect as that in Embodiment 1 or 2, which will not be repeated here.

[0089] In Embodiment 2, it is specifically mentioned that the meshing structure 12 can adopt an arc-shaped meshing band 12.1 based on the gear design process. Therefore, as one embodiment, the meshing structure design parameters include: tooth profile module, number of teeth, and gear tilt control angle; wherein, the gear tilt control angle is a parameter defined in this application, and the method for obtaining it is: referring to... Figure 4 and Figure 14 Obtain the pitch circles 123 of two adjacent arc-shaped meshing zones 12.1 along the arm shaft axis, and draw the line connecting the centers of the two pitch circles 123. Get the center line The angle difference relative to the axis of the arm shaft, this angle difference is the gear tilt control angle. ;

[0090] refer to Figure 15 And its x-axis, y-axis, and origin. Based on the primary model, a Cartesian coordinate system is constructed with the arm axis centerline in an unloaded state. The arm axis centerline of the primary model is used as the y-axis, and the x-axis is drawn on a plane perpendicular to the y-axis, with the starting point of the arm axis centerline as the origin. Obtain the coordinates of the center point of the initial segment of the helix in the primary model. Set the rotation angle of each segment of the helix relative to the unit above it; observe. Figure 15 The center point of the first segment after the initial segment of the spirochete is The center point of the second segment after the initial segment of the spirochete is And so on; see reference Figure 14 and Figure 15 The point of tangency between the pitch circle 123 of the arc-shaped meshing zone 12.1 of the first segment of the helix and the pitch circle 123 of the arc-shaped meshing zone 12.1 of the initial segment of the helix is... The point of tangency between the pitch circle 123 of the arc-shaped meshing band 12.1 of the second section of the helical body and the pitch circle 123 of the arc-shaped meshing band 12.1 of the first section of the helical body is... ,include The same logic applies to the remaining points;

[0091] Based on the coordinates of the center point of the initial segment and the rotation angle of the unit, the coordinates of the center point of each segment of the spiral are estimated segment by segment, i.e., from... Begin by obtaining the center point coordinates of each segment of the helix, and then fit a curved arc based on the center point coordinates of all segments of the helix. Calculate the curved arc external tangent connection angle external tangent connection angle Tangent and tangent The connection angle, in response to the external tangent connection angle If the angle difference between the maximum design bending angle and the maximum design bending angle is greater than the error threshold, the design can be considered substandard. In general, this is caused by the design of the arc meshing band 12.1 hindering the movement of the spiral body 11. The gear tilt control angle needs to be updated so that the arc meshing band 12.1 can meet the movement requirements of the spiral body 11.

[0092] If the angle difference between the external tangent connection angle and the maximum design bending angle is not greater than the error threshold, the design can be considered to meet the standard. Further model collision detection is required to obtain the edge contour coordinates of each segment of the helix. If the edge contour coordinates of any segment of the helix are located within the contours of other segments, the output is a collision overlap result with conflict; otherwise, the output is a collision overlap result without conflict.

[0093] The output process for conflict overlap results can be achieved by detecting whether the y-axis coordinates of adjacent edge contour points are within the contours of other sections. Figure 6 For example, we can observe the first helix. The solid line outline of the section and the first helix The edge contour points of the section are And the bent helix The dashed outline of the section and its edge outline points If the bent helix is ​​the first Section outline edge outline point Located in the helical body If the condition is outside the specified section, it is assumed that there is no conflict, and the output is the result of conflict overlap without conflict; otherwise, the output is the result of conflict overlap with conflict.

[0094] As one embodiment, the step-by-step estimation of the center point coordinates of each segment of the helix includes:

[0095] Obtain the coordinates of the center point of a known segment of the helix;

[0096] The coordinates of the center point of the unknown segment of the helix after the known segment are obtained by calculating the following formula:

[0097] ,

[0098] In the formula, The coordinates of the center point of the unknown segment of the helix. Given the coordinates of the center point of a known segment of the helix, For coordinate change amount, For the tooth profile module, Number of teeth For gear tilt control angle, Let be the angle of revolution of the unknown segment of the helix relative to the known segment of the helix. The periodic pitch of a single helix. The number of spirochetes. The rotation angle of the unit;

[0099] In response to the gear tilt control angle and the revolution angle of the unknown segment of the helical body relative to the known segment of the helical body both being less than the corresponding threshold angle, the coordinates of the center point of the unknown segment of the helical body after the known segment are calculated using the following formula:

[0100] .

[0101] As one embodiment, the corresponding threshold angles are 30° and 15°, respectively, for reference. Figure 6After the main body of the spiral 11 bends, with the unknown segment of the spiral as a fixed reference object, the known segment of the spiral will revolve counterclockwise around the unknown segment of the spiral. The line connecting the centers of the circles... Transform into a line connecting the centers The center point of the unknown segment of the helix Become The unknown segment of the helix itself also rotates; the angle of rotation... Less than 30°, the revolution angle of the unknown segment of the helix relative to the known segment of the helix. When the angle is less than 15°, taking into account , This is the theoretical basis for the calculation of the formula above. Furthermore, in the formula... This corresponds to the distance from the known segment center point of the spirochete to the meshing point. The coordinate difference, Point of engagement arrive The coordinate difference.

[0102] As one embodiment, in response to either the gear tilt control angle or the revolution angle of the unknown segment of the helical body relative to the known segment of the helical body, which is greater than or equal to the corresponding threshold angle, finite element modeling is performed based on the known geometric design information mentioned above, and the coordinates of the unknown segment of the helical body are obtained based on the modeling results.

[0103] refer to Figure 9 and Figure 10The bolded portion in the figure represents the contact area 121.5 when adjacent arc-shaped meshing bands 12.1 mesh with each other during bending of the helical body 11. Based on this, it can be determined that the edge of the arc-shaped meshing band 12.1 is designed to allow for the cutting of complete teeth 121.3 to obtain incomplete teeth 121.1, thus filling the subtractive portion 122 at the edge of the arc-shaped meshing band 12.1. When filling the subtractive portion 122 at the edge of one of the adjacent arc-shaped meshing bands 12.1, the shape of the incomplete tooth 121.1 of the other adjacent arc-shaped meshing band 12.1 and its related transition surface are used, so that when the helical body 11 reaches its maximum bending angle, the incomplete tooth 121.1 engages with the opposite filled subtractive portion 122. During the design process, a comprehensive design is required based on the overlap and gap size between the complete tooth 121.3 at the edge of the arc-shaped meshing band 12.1 and the opposite subtractive portion 122 at the maximum bending angle, according to the finite element model. Particularly for the removed portion of the incomplete tooth 121.1, the contact area 121.5 between the complete tooth 121.3 and the helix on the other side at the maximum bending angle is determined based on the finite element model. Then, the tooth profile above the contact area 121.5 is cut off using a planar cutting modeling method. Next, a transition surface 121.2 is created between the planar cut surface 121.1.1 and the adjacent area 121.4 using a surface scanning method. After completion, finite element simulation tests are conducted again to check whether the interference between the arc-shaped meshing bands 121.1 affects the maximum bending angle of the bent arm 1.

[0104] In Examples 1 and 2, the spiral body 11 is a double helix structure, which is generated as follows: A spatial rectangular coordinate system is constructed, and first, the helix is ​​generated. The formula for generating the helix is ​​as follows:

[0105] ,

[0106] In the formula, For pitch, The progress parameter of the spiral. The outer diameter of the curved arm. , and Generate three-dimensional coordinates on the spiral.

[0107] A two-dimensional shape, such as a rectangle, is defined for sweeping. This two-dimensional shape is then used to sweep along a pre-generated spiral to obtain a spiral body. Due to the number of spiral bands in Examples 1 and 2... Therefore, the two helices are arranged at 180° intervals to obtain the first helice 111 and the second helice 112. Then, an arc-shaped meshing band 12.1 is designed on the basis of the helices.

[0108] 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.

[0109] 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."

[0110] 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 continuous robotic arm, characterized in that, include: The curved arm (1) includes at least a first helical body (111) and a second helical body (112) arranged around the arm axis. The first helical body (111) and the second helical body (112) have multiple force-transmitting contacts. The first helical body (111) and the second helical body (112) are respectively provided with meshing structures (12). When the curved arm (1) is bent, the meshing structures (12) of the first helical body (111) and the meshing structures (12) of the second helical body (112) mesh together. The meshing structure (12) includes an arc-shaped meshing band (12.1), which includes alternating additive portions (121) and subtractive portions (122). The arc-shaped meshing bands (12.1) are respectively disposed on the first helical body (111) and the second helical body (112), and are distributed along the helical direction of the first helical body (111) and the second helical body (112). The arc-shaped meshing bands (12.1) that are adjacent along the arm shaft axis mesh with each other. The arc-shaped meshing band (12.1) includes an additive portion (121) and a subtractive portion (122) arranged alternately with the center of the set pitch circle (123) to make meshing rolling contact occur between adjacent arc-shaped meshing bands (12.1) along the arm axis when the curved arm body (1) bends. The additive portion (121) includes complete teeth (121.3) and incomplete teeth (121.1) located at the edge of the arcuate meshing band (12.1), the incomplete teeth (121.1) also smoothly transitioning between the portion of the helix where the arcuate meshing band (12.1) is not provided via a transition surface (121.2).

2. The continuous robotic arm according to claim 1, characterized in that, It also includes a cable mounting component (2), which is fitted into the curved arm body (1); the cable mounting component (2) has multiple cable grooves (2.1) inside or on its surface, which are used to install cables (3), and the multiple cables (3) are used to perform antagonistic control on the continuous robotic arm; Alternatively, the spiral body (11) of the curved arm (1) bends toward the arm axis to form a cable groove (2.1), the cable groove (2.1) is used to install cables (3), and multiple cables (3) are used for antagonistic control of the continuous robotic arm.

3. The 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).

4. The 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 member (4) and the support base (5) respectively. The two ends (13) of the cable mounting member (2) are respectively separated from the cable fixing member (4) and the support base (5) by a third gap (2.2) of a set width.

5. A method for acquiring a continuous robotic arm as described in any one of claims 1 to 4, characterized in that, include: The pitch of a single helix and the outer diameter of the robotic arm are set, and the generation formula of the single helix is ​​obtained based on the pitch of the single helix and the outer diameter of the robotic arm. The number of spirals is set, and the interval angle between adjacent spirals is obtained based on the number of spirals. Obtain the design parameters of the meshing structure; model the primary model based on the design parameters of the meshing structure, the generation formula of the single helix, and the interval angle between adjacent helices. The maximum design bending angle is simulated on the primary model to obtain the conflict and overlap results of adjacent helices. In response to the conflict and overlap results indicating the existence of conflict, the meshing structure design parameters are updated until the conflict and overlap results indicate the absence of conflict, and the final model is output. A continuous robotic arm is obtained based on the final model; The meshing structure design parameters include: tooth profile module, number of teeth, and gear inclination control angle; Obtain the pitch circle (123) of two adjacent arc-shaped meshing bands (12.1) along the arm shaft axis, draw the line connecting the centers of the two pitch circles (123), and obtain the angle difference between the line connecting the centers and the arm shaft axis to obtain the gear tilt control angle; Based on the primary model, a Cartesian coordinate system is constructed with the arm axis centerline under no-force conditions. The coordinates of the starting segment center point of the spiral in the primary model are obtained, and the rotation angle of each segment of the spiral relative to the previous segment is set. Based on the center point coordinates of the starting section and the unit rotation angle, the center point coordinates of each section of the spiral are estimated section by section. A bending arc is fitted based on the center point coordinates of all sections of the spiral. The external tangent connection angle of the bending arc is calculated. In response to the angle difference between the external tangent connection angle and the maximum design bending angle being greater than the error threshold, the gear tilt control angle is updated. In response to the fact that the angle difference between the external tangent connection angle and the maximum design bending angle is not greater than the error threshold, the edge contour coordinates of each segment of the helical body are obtained. In response to the fact that the edge contour coordinates of any segment of the helical body are located within the contours of other segments, the output is a conflict overlap result with conflict; otherwise, the output is a conflict overlap result without conflict.

6. The method for acquiring a continuous robotic arm according to claim 5, characterized in that, The method of estimating the center point coordinates of each segment of the helix segment by segment includes: Obtain the coordinates of the center point of a known segment of the helix; The coordinates of the center point of the unknown segment of the helix after the known segment are obtained by calculating the following formula: ； In the formula, The coordinates of the center point of the unknown segment of the helix. Given the coordinates of the center point of a known segment of the helix, For coordinate change amount, For the tooth profile module, Number of teeth For gear tilt control angle, Let be the angle of revolution of the unknown segment of the helix relative to the known segment of the helix. The periodic pitch of a single helix. The number of spirochetes. The rotation angle of the unit; In response to the gear tilt control angle and the revolution angle of the unknown segment of the helical body relative to the known segment of the helical body both being less than the corresponding threshold angle, the coordinates of the center point of the unknown segment of the helical body after the known segment are calculated using the following formula: 。

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