Flexible manipulator for working in narrow cavities

Abstract

The application discloses a flexible mechanical arm for narrow cavity operation, which comprises a flexible snake bone arm, a snake bone base and a rope driving box; the length-diameter ratio of the flexible snake bone arm is 80-240; the flexible snake bone arm is swingably installed on the snake bone base, and a plurality of snake bone joints are sequentially arranged on the flexible snake bone arm along the length direction of the flexible snake bone arm; the plurality of snake bone joints each have two opposite swing directions; the snake bone base is connected and fixed with the rope driving box; the rope driving box is provided with worm gear driving units and winding drums; the worm gear driving units are used for driving the winding drums to rotate in the forward and reverse directions; the driving ropes are wound on the winding drums; each two driving ropes are taken as a group, and the driving ropes are connected with the snake bone joint ropes; after the scheme is adopted, the flexible mechanical arm has an ultra large length-diameter ratio, and the driving box structure can be small enough.

Description

Technical Field

[0001] This invention relates to the technical field of robotic arms, and in particular to a flexible robotic arm for working in narrow cavities. Background Technology

[0002] With the continuous development of technology, the demand for narrow cavity operations in medical, industrial inspection and other fields is increasing. Examples include: non-invasive early detection of nasopharyngeal carcinoma via natural cavities using nasal swabs; and non-destructive testing of narrow cavities in critical components such as aero-engine compressors, combustion chambers, and turbines. However, common endoscopes are often passively compliant, such as the flexible endoscope (patent number CN119112073A, titled "Flexible Endoscope"), which proposes a flexible endoscope with a controllable snake-like appendage. However, the endoscope frequently comes into contact with the target object during operation, easily damaging both the object and the endoscope. Furthermore, the endoscope's tip lacks load-bearing capacity. Traditional rigid robotic arms, due to their structural characteristics, possess strong load-bearing capacity, high control precision, and low control difficulty. However, these arms are often large and unsuitable for tasks within narrow cavities.

[0003] For example, the drive box of a common rope-driven robotic arm is usually driven by a lead screw; for example, patent number CN202510153082.1, patent name: A modular segmented linkage flexible robotic arm and a segmented decoupling drive method for rope bundles. However, this method makes the drive box very large, which is redundant in terms of space; in addition, this method cannot drive the arm with a diameter of 5mm, and lacks adaptability.

[0004] Faced with the above problems, there is an urgent need for a technical solution that can have an ultra-large length-to-diameter ratio and a sufficiently small drive box structure. Summary of the Invention

[0005] The purpose of this invention is to provide a flexible robotic arm for working in narrow cavities, so that it has an ultra-high aspect ratio and the drive box structure can be made small enough.

[0006] To address the aforementioned technical problems, this invention provides a flexible robotic arm for operations in confined spaces, comprising a flexible snake-bone arm, a snake-bone base, and a rope drive box. The flexible snake-bone arm has a length-to-diameter ratio of 80-240. It is mounted on the snake-bone base in a swingable manner, and along its length, the arm has multiple snake-bone joints, each with two opposite swinging directions. The snake-bone base is fixedly connected to the rope drive box. The rope drive box includes worm gear drive units and winding drums. The worm gear drive units drive the winding drums in both forward and reverse directions. Drive ropes are wound around the winding drums, and multiple sets of drive ropes are connected to the multiple snake-bone joints in pairs.

[0007] In one embodiment, the flexible snake-bone arm includes multiple snake-bone arm segments, which are sequentially rotatably connected to each other. One of the snake-bone arm segments, placed at the starting position, is rotatably connected to the snake-bone base to form multiple snake-bone joints of the flexible snake-bone arm.

[0008] In one embodiment, each of the two opposite ends of the snake-bone arm segment is provided with two oppositely arranged ear plates, and the holes of the ear plates at both ends of the snake-bone arm segment are axially perpendicular to each other; adjacent snake-bone arm segments are connected to form a rotatable structure by aligning the corresponding ear plates with each other and inserting rivets.

[0009] In one embodiment, the snake-bone arm segment is provided with multiple rope-threading channels, which are arranged separately around the central axis of the snake-bone arm segment and are all used for the drive rope to be connected to the drive rope.

[0010] In one embodiment, the surface of the rope-threading channel is coated with a wear-resistant lubricating coating.

[0011] In one embodiment, the wear-resistant lubricating coating is a Teflon coating.

[0012] In one embodiment, the snake-bone arm segment is provided with a tool channel, the axis of which is aligned with the central axis of the snake-bone arm segment.

[0013] In one embodiment, the worm gear drive unit includes a drive motor capable of forward and reverse rotation control, a worm coaxially connected to the output shaft of the drive motor, and a worm wheel meshing with the worm for transmission, wherein the worm wheel and the winding drum are connected in a structure with the same rotation axis.

[0014] In one embodiment, the rope drive box is further provided with a rope-winding wheel force measuring mechanism and a rope-winding guide wheel; multiple drive ropes pass through the corresponding rope-winding wheel force measuring mechanism and the corresponding rope-winding guide wheel in sequence, and then connect to the corresponding snake-bone joint rope drive.

[0015] In one embodiment, the rope-wound force measuring mechanism includes a force sensor, a force measuring bracket, and a force-measuring rope-wound wheel; one end of the force sensor is fixedly connected to the rope drive box, and the other end of the force sensor is fixedly connected to the force measuring bracket, and the two ends of the force sensor are connected to a zigzag force monitoring and sensing structure; the force-measuring rope-wound wheel is rotatably mounted on the force measuring bracket; the drive rope is wound around the side of the force-measuring rope-wound wheel away from the force sensor.

[0016] The beneficial effects of this invention are as follows:

[0017] 1. This solution utilizes a rope drive box to perform segmented linkage control of the flexible snake arm via a drive rope, thereby solving the problem of the robotic arm operating in narrow cavities.

[0018] 2. Install a rope-wound wheel-type force measuring mechanism. Through a triangular force measuring scheme, the tension on the rope can be converted into the pressure of the rope on the rope-wound wheel-type force measuring mechanism for measurement, thereby completing the collection of force information on the flexible snake-bone arm and providing force information for related tasks.

[0019] 3. The rope drive box adopts a worm gear drive unit, wherein the worm gear and the winding drum are connected with the same rotation axis, which is equivalent to the worm gear serving as both a transmission component and a rope storage drum, greatly reducing the size of the drive box. At the same time, due to the self-locking characteristics of the worm gear itself, it effectively reduces the drift of the drive motor in applications with strong vibration and load, and improves the positioning accuracy of the flexible snake arm under harsh working conditions.

[0020] 4. The flexible robotic arm of this invention combines high degree of freedom, segmented linkage, and ultra-fine diameter. The drive motor and the rope-winding wheel force measuring mechanism are concentrated in the rope drive box, far away from the end-effector working environment. Therefore, in the medical field, it can flexibly move through the natural cavities of the human body to achieve precise operation. In the industrial testing field, it can cope with extreme environments such as heavy oil pollution, high toxicity, and strong radiation, showing excellent environmental adaptability and is widely applicable to the operational needs under complex working conditions. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure provided in an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 A schematic diagram of the flexible snake-bone arm structure;

[0024] Figure 3 yes Figure 2 A schematic diagram of the snake-bone arm segment structure;

[0025] Figure 4 yes Figure 1 A schematic diagram of the rope drive box structure;

[0026] Figure 5 yes Figure 4 A partial disassembly diagram;

[0027] Figure 6 This is a schematic diagram of the drive rope winding provided in an embodiment of the present invention.

[0028] The attached figures are labeled as follows:

[0029] 100. Flexible snake-bone arm; 110. Snake-bone joint; 120. Snake-bone arm segment; 121. Ear plate; 122. Rope passage; 123. Tool passage; 130. Rivet;

[0030] 200. Snake-bone base;

[0031] 300. Rope drive box; 310. Worm gear drive unit; 311. Drive motor; 312. Worm; 313. Worm gear; 320. Winding drum; 330. Drive rope; 340. Rope winding wheel type force measuring mechanism; 341. Force sensor; 342. Force measuring bracket; 343. Force measuring rope winding wheel; 350. Rope winding guide wheel. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] This invention provides a flexible robotic arm for working in confined spaces, such as... Figure 1 As shown, it includes a flexible snake-bone arm 100, a snake-bone base 200, and a rope drive box 300.

[0034] Regarding the flexible snake-bone arm 100, as Figures 1 to 2As shown, in this embodiment, the flexible snake arm 100 is mounted on the snake base 200 in a swingable manner. Along the length of the flexible snake arm 100, the flexible snake arm 100 is provided with a plurality of snake joints 110 in sequence. Each of the plurality of snake joints 110 has two swingable directions in opposite directions, thereby enabling the flexible snake arm 100 to perform swing control with a higher degree of freedom to meet the needs of various application scenarios.

[0035] Specifically, such as Figures 1 to 3 As shown, in order to form multiple snake-bone joints 110, this embodiment sets the flexible snake-bone arm 100 to include multiple snake-bone arm segments 120, each of which is cylindrical. The multiple snake-bone arm segments 120 are sequentially rotatably connected to each other, and one snake-bone arm segment 120 placed at the starting position is rotatably connected to the snake-bone base 200 to form multiple snake-bone joints 110 of the flexible snake-bone arm 100.

[0036] In order to achieve the rotational connection between adjacent snake-bone arm segments 120, as shown in the figure Figure 2 and 3 As shown, in this embodiment, each end of the snake-bone arm segment 120 is provided with two oppositely arranged ear plates 121, and the holes of the ear plates 121 at both ends of the snake-bone arm segment 120 are perpendicular to each other, so that the four ear plates 121 on one snake-bone arm segment 120 are approximately arranged at the four ends of a cross; and adjacent snake-bone arm segments 120 are connected to a rotatable structure by aligning the corresponding ear plates 121 with each other and inserting rivets 130, so that the swing directions of adjacent snake-bone arm segments 120 are different from each other.

[0037] In addition, since the flexible snake-bone arm 100 is driven by a rope, in order to facilitate the arrangement of the ropes, such as Figure 2 and Figure 3 As shown, in this embodiment, the snake-bone arm segment 120 is provided with multiple rope-threading channels 122. The multiple rope-threading channels 122 are arranged separately around the central axis of the snake-bone arm segment 120. At this time, the corresponding ropes can reach the required position and be connected and fixed through the rope-threading channels 122, so that multiple rope-threading channels 122 can be used for the drive rope to make rope drive connection.

[0038] To prevent the rope from being easily damaged by friction, this embodiment also coats the surface of the rope channel 122 with a wear-resistant and lubricating coating. For example, setting the wear-resistant and lubricating coating to be a Teflon coating is a better choice. After adopting this setting, the friction between the rope and the rope channel 122 can be reduced, the service life of the rope can be extended, and the smoothness of rope drive operation can be improved.

[0039] Furthermore, the main function of the flexible snake arm 100 is to load the tool to perform various required operations. Therefore, in order to facilitate the loading of the tool, such as... Figures 1 to 3 As shown, in this embodiment, the snake arm segment 120 is provided with a tool channel 123. The axis of the tool channel 123 is consistent with the central axis of the snake arm segment 120. Therefore, when it is used, instruments such as cameras can pass through multiple tool channels 123 of the snake arm segment 120 to facilitate shooting at the operating end of the flexible snake arm 100. Other available instruments can also be used in this way.

[0040] Furthermore, the aspect ratio of the flexible snake arm 100 is the ratio of its length to its diameter. To meet the needs of more application scenarios, the flexible snake arm 100 needs to have an ultra-large aspect ratio. Therefore, in this embodiment, the diameter of the flexible snake arm 100 is set to 5mm and the length to 1.2m, thereby achieving an ultra-large aspect ratio of the flexible snake arm 100.

[0041] At this point, the diameter of the flexible snake arm 100 is essentially determined by the diameter of the snake arm segment 120, while the length of the flexible snake arm 100 is determined by the number of snake arm segments 120. Of course, the flexible snake arm 100 is not limited to the above-mentioned diameter and length. As long as the length-to-diameter ratio of the flexible snake arm 100 is set to 80-240, it is within a relatively optimal range. This not only meets the needs of more application scenarios, but also ensures that the rope drive box 300 of this embodiment can reliably drive it.

[0042] Regarding the snake-bone base 200, as Figure 1 and Figure 2 As shown, in this embodiment, the snake bone base 200 is configured as a disc-shaped structure. The snake bone base 200 is connected and fixed to the rope drive box 300, thereby realizing the assembly and connection between the flexible snake bone arm 100, the snake bone base 200 and the rope drive box 300.

[0043] Regarding the aforementioned rope drive box 300, such as Figure 1 , Figure 4 and Figure 6 As shown, in this embodiment, the rope drive box 300 is equipped with a worm gear drive unit 310 and a winding drum 320; the multiple worm gear drive units 310 are used to drive the multiple winding drums 320 to rotate in both directions; each of the multiple winding drums 320 is wound with a drive rope 330, and multiple sets of drive ropes are connected to multiple snake joint rope drives in a manner where two drive ropes 330 form a group.

[0044] The worm gear drive unit 310 mainly provides driving force for rope drive control, and utilizes the self-locking characteristics of the worm gear structure to effectively reduce motor drift and improve the positioning accuracy of the flexible snake arm 100 under harsh working conditions in application scenarios with strong vibration and load.

[0045] Therefore, in order to achieve this goal, such as Figure 4 and Figure 5 As shown, in this embodiment, the worm gear drive unit 310 includes a drive motor 311 capable of forward and reverse rotation control, a worm 312 coaxially connected to the output shaft of the drive motor 311, and a worm wheel 313 meshing with the worm 312 for transmission. The worm wheel 313 and the winding drum 320 are connected to each other with the same rotation axis.

[0046] At this time, the forward and reverse rotation of the drive motor 311 can control the forward and reverse rotation of the winding drum 320 through the worm gear 312 and worm wheel 313, thereby realizing the rope winding and unwinding control required for rope drive control; moreover, since the worm wheel 313 and the winding drum 320 are connected with the same rotation axis, the two form an integral structure, possessing the characteristics of both the worm wheel 313 and the winding drum 320, which facilitates a significant reduction in the size of the rope drive box 300, meeting the design requirement that the drive box structure can be made small enough.

[0047] Furthermore, to achieve accurate control of the flexible snake-like arm 100, it is necessary to accurately monitor the tension and force of multiple drive ropes 330. Therefore, as Figures 4 to 6 As shown, in this embodiment, the rope drive box 300 is also equipped with a rope winding wheel force measuring mechanism 340 and a rope winding guide wheel 350; multiple drive ropes 330 pass through the corresponding rope winding wheel force measuring mechanism 340 and the corresponding rope winding guide wheel 350 in sequence, and then connect to the corresponding snake joint rope drive.

[0048] With this setup, since the drive rope 330 will bypass the rope wheel force measuring mechanism 340, the rope wheel force measuring mechanism 340 will be able to monitor the force on the drive rope 330 and thus be able to sense the monitoring results and make corresponding controls.

[0049] In this embodiment, the rope-wheel type force measuring mechanism 340 is as follows: Figure 5 and Figure 6 As shown, the rope-wheel type force measuring mechanism 340 includes a force sensor 341, a force measuring bracket 342, and a force measuring rope wheel 343. One end of the force sensor 341 is connected and fixed to the rope drive box 300, and the other end of the force sensor 341 is connected and fixed to the force measuring bracket 342. The two ends of the force sensor 341 are connected to a tortuous force monitoring and sensing structure. The force measuring rope wheel 343 is rotatably mounted on the force measuring bracket 342. The side of the force measuring rope wheel 343 away from the force sensor 341 is around which a drive rope 330 passes.

[0050] With this configuration, due to the tortuous force monitoring and sensing structure between the two ends of the force sensor 341, when the drive rope 330 is wound and released by the force measuring rope wheel 343, the force sensor 341 is more likely to deform and realize force monitoring, thereby greatly improving the accuracy and timeliness of force monitoring of the drive rope 330.

[0051] Specifically, the aforementioned drive rope 330 uses a triangular force-measuring rope-threading scheme, which can realize the tension on the rope. The pressure F exerted by the rope on the force sensor 341 is measured, and the tension on the rope is also measured. This enables force sensing of the flexible snake-like arm 100.

[0052] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A flexible robotic arm for working in confined spaces, characterized in that, Includes a flexible snake-bone arm, a snake-bone base, and a rope drive box; The flexible snake-bone arm has a length-to-diameter ratio of 80-240. The flexible snake-bone arm is mounted on the snake-bone base in a swingable manner. Along the length direction of the flexible snake-bone arm, the flexible snake-bone arm is provided with a plurality of snake-bone joints in sequence. Each of the plurality of snake-bone joints has two swingable directions in opposite directions. The flexible snake-bone arm includes multiple snake-bone arm segments, which are sequentially rotatably connected to each other. One of the snake-bone arm segments, placed at the starting position, is rotatably connected to the snake-bone base to form multiple snake-bone joints of the flexible snake-bone arm. The snake-bone arm segment is provided with multiple rope-threading channels, which are arranged separately around the central axis of the snake-bone arm segment. All of the rope-threading channels are used for the drive rope to be connected to the drive rope. The surface of the rope threading channel is coated with a wear-resistant and lubricating coating, which is a Teflon coating. The snake-bone base is fixedly connected to the rope drive box; The rope drive box is equipped with a worm gear drive unit and a winding drum; the multiple worm gear drive units are used to drive the multiple winding drums to rotate in the forward and reverse directions respectively; each of the multiple winding drums is wound with a drive rope, and the multiple sets of drive ropes are connected to the multiple snake joint rope drives in a way that each set of two drive ropes is a group. The rope drive box is also equipped with a rope winding wheel type force measuring mechanism and a rope winding guide wheel; Multiple drive ropes sequentially pass around the corresponding rope-winding wheel force measuring mechanism and the corresponding rope-winding guide wheel, and then connect to the corresponding snake-bone joint rope drive. The rope-winding wheel type force measuring mechanism includes a force measuring sensor, a force measuring bracket, and a force measuring rope-winding wheel; One end of the force sensor is connected and fixed to the rope drive box, and the other end of the force sensor is connected and fixed to the force measuring bracket. The two ends of the force sensor are connected to a tortuous force monitoring and sensing structure. The force measuring rope wheel is rotatably mounted on the force measuring bracket; The drive rope is wrapped around the side of the force-measuring reel away from the force sensor.

2. The flexible robotic arm according to claim 1, characterized in that, The snake-bone arm segment has two oppositely arranged ear plates at both ends, and the holes of the ear plates at both ends of the snake-bone arm segment are perpendicular to each other axially. The adjacent snake-bone arm segments are connected to each other by means of corresponding ear plates being aligned and rivets being inserted, forming a rotatable structure.

3. The flexible robotic arm according to claim 1, characterized in that, The snake-bone arm segment is provided with a tool channel, and the axial direction of the tool channel is consistent with the central axial direction of the snake-bone arm segment.

4. The flexible robotic arm according to claim 1, characterized in that, The worm gear drive unit includes a drive motor capable of forward and reverse rotation control, a worm coaxially connected to the output shaft of the drive motor, and a worm wheel meshing with the worm for transmission, wherein the worm wheel and the winding drum are connected in a structure with the same rotation axis.

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