Integrated continuum manipulator for grasping

Abstract

The application relates to the technical field of robots, in particular to a one-body continuum manipulator for grabbing. The manipulator comprises a driving mechanism, a coupling manipulator arm body and a grabbing mechanism which are sequentially connected; the coupling manipulator arm body is provided with driving ropes which are circumferentially distributed; the coupling manipulator arm body comprises a flexible rod and a plurality of spherical friction bodies which are sleeved on the flexible rod; the plurality of spherical friction bodies are sequentially connected in a head-to-tail mode; a serpentine spring which is circumferentially distributed is arranged between adjacent spherical friction bodies; and the bottom of the coupling manipulator arm body is provided with an electromagnetic rigidity adjusting assembly which is used for adjusting the friction force of the plurality of spherical friction bodies to realize the rigidity adjustment of the coupling manipulator arm body. The one-body continuum manipulator for grabbing adopts the continuum joint of the coupling of the serpentine spring and the spherical friction body, realizes the rigidity adjustment, improves the load capacity under the condition of guaranteeing the flexibility.

Description

An integrated continuous robotic arm for grasping Technical Field

[0001] This invention relates to the field of robotics, and more particularly to an integrated continuous robotic arm for grasping. Background Technology

[0002] Continuum robots, with their unique flexibility and high-degree-of-freedom motion capabilities, have shown great potential and are widely used in the exploration of deep cavities and confined spaces (such as pipeline inspection and engine maintenance). However, traditional continuum robots struggle to balance the trade-off between structural stiffness and load-bearing capacity. Existing technologies are mainly developing in two directions:

[0003] The first category is variable stiffness solutions driven by smart materials such as pneumatics, hydraulics, or shape memory alloys. While these solutions can achieve a certain degree of stiffness variation, their inherent drawbacks are also quite obvious: pneumatic and hydraulic drives suffer from the problems of compressible media and slow response, resulting in low passive stiffness and a significant decrease in end-effector motion accuracy during long-distance transmission through long pipelines; shape memory alloys, on the other hand, suffer from bottlenecks such as thermal hysteresis, high energy consumption, and slow cooling. These factors limit their application in reliable industrial scenarios requiring high precision and high loads.

[0004] The second type employs a cable-driven, constant-stiffness continuum structure. While this type of robot is relatively simple to control, its stiffness is usually determined by the material itself. Once deformation occurs, it struggles to actively resist external loads, resulting in generally weak load-bearing capacity. To achieve a sufficient working range, the size of the drive unit often needs to be increased, leading to a bulky system with poor mobility, creating a vicious cycle of "scale-performance."

[0005] Therefore, there is an urgent need for a continuum robot that possesses both flexibility and safety, while also overcoming the limitations of existing technologies in terms of stiffness, load, and accuracy, so as to truly meet the high standards required for integrated detection and operation in complex deep cavity environments. Summary of the Invention

[0006] The purpose of this invention is to provide an integrated continuous robotic arm for grasping, thereby solving the aforementioned technical problems.

[0007] To achieve the above objectives, the present invention provides an integrated continuous robotic arm for grasping, comprising a drive mechanism, a coupled robotic arm body, and a grasping mechanism connected in sequence.

[0008] The coupled robotic arm has circumferentially distributed drive ropes on its body. The coupled robotic arm includes a flexible rod and several spherical friction bodies fitted on the flexible rod. The spherical friction bodies are connected end to end in sequence. A circumferentially distributed serpentine spring is set between adjacent spherical friction bodies. An electromagnetic stiffness adjustment component is set at the bottom of the coupled robotic arm. The electromagnetic stiffness adjustment component is used to adjust the friction force of the spherical friction bodies to adjust the stiffness of the coupled robotic arm.

[0009] Preferably, the drive mechanism includes a chain joint adjustment motor; the chain joint adjustment motor is mounted on the rear support, and the drive cylinder is rotatably mounted on the front support via a fixed plate. A rotating bracket is provided between the front and rear supports. The rotating bracket includes a first fixed plate, a second fixed plate, and a third fixed plate. Several circumferentially distributed tensioning mechanisms are provided between one side of the first fixed plate and the second fixed plate. Several L-shaped connectors are circumferentially distributed on the other side of the second fixed plate. One side of the third fixed plate is connected to the output shaft of the chain joint adjustment motor. A polygonal fixing ring is installed on the other side of the third fixed plate via a length adjustment stud. Several circumferentially distributed slides are fixedly installed between the polygonal fixing ring and the several L-shaped connectors. A movable pulley is installed on the slider inside the slide. A chain tensioning mechanism is provided inside the rotating bracket.

[0010] Preferably, the tensioning mechanism includes a tensioning U-shaped frame, with fixed reversing pulleys symmetrically installed on the inner side of the tensioning U-shaped frame, and an adjusting pulley installed on the bottom inner side of the tensioning U-shaped frame via a tension adjusting support. An adjusting nut is provided on the stud of the tension adjusting support, and the tensioning U-shaped frame is installed on the second fixed plate.

[0011] Preferably, the chain tensioning mechanism includes a chain drive motor mounted on a third fixed plate. The chain drive motor is fixed to one end of the chain drive housing, and the output shaft of the chain drive motor is connected to a single-sided drive chain via a gear transmission assembly. The gear transmission assembly includes two meshing first bevel gears and second bevel gears. The first bevel gear is mounted on the output shaft of the chain drive motor, and the second bevel gear is mounted on a first rotating shaft. The first rotating shaft is rotatably mounted inside the chain drive housing. A first transmission wheel is provided on the first rotating shaft, and the first transmission wheel is connected to a second transmission wheel on a second rotating shaft via a transmission belt. The second rotating shaft is rotatably mounted inside the chain drive housing, and a chain drive gear is provided on the second rotating shaft. The chain drive gear is connected to the single-sided drive chain. One end of the single-sided drive chain is slidably disposed inside the chain drive housing, and the other end of the chain drive housing is mounted on the first fixed plate. The other end of the single-sided drive chain passes through the chain drive housing and is connected to one side of the fixed disc.

[0012] Preferably, the electromagnetic stiffness adjustment assembly includes an electromagnetic coil and a permanent magnet arranged in parallel, with the electromagnetic coil mounted on the other side of the fixed disk and the permanent magnet in contact with the spherical friction body located at the front.

[0013] Preferably, the spherical friction body includes, from the outside to the inside, a cross-shaped ball ring, an outer friction layer, a sliding ball ring, a middle friction layer, a connecting layer, and an inner friction layer; the upper and lower sides of the inner friction layer are semi-hollow spheres and connected to the connecting layer; the lower side of the connecting layer is in contact with the inner friction layer; the upper side of the connecting layer is in contact with the lower side of the middle friction layer; the upper side of the connecting layer has a hollow cylinder that passes through the sliding ball ring and connects to the ball-and-socket joint; connecting pieces are provided on both the middle friction layer and the outer friction layer, and the connecting pieces are fixedly connected to the inner friction layer; the upper side of the middle friction layer is in contact with the lower side of the sliding ball ring; the upper side of the sliding ball ring is in contact with the lower side of the outer friction layer; the upper side of the outer friction layer is in contact with the cross-shaped ball ring; the outer side of the cross-shaped ball ring is in contact with the inner side of the ball-and-socket joint; a groove is provided on both the upper side of the outer friction layer and the inner side of the ball-and-socket joint; a slide rail is provided on both the inner and outer sides of the cross-shaped ball ring, and the slide rail is located in the corresponding groove.

[0014] A mounting plate is provided in the middle of the inner friction layer. The mounting plate has a through hole for the wire, and the two ends of the serpentine spring are fixed to the adjacent mounting plates respectively.

[0015] Preferably, the drive rope includes at least one set of joint drive ropes and chain joint drive ropes; one end of several chain joint drive ropes is fixed to the mounting plate of the first spherical friction body and is circumferentially distributed; one end of at least three joint drive ropes in each set is fixed to the mounting plate of the corresponding spherical friction body and is circumferentially distributed; the other ends of the chain joint drive ropes and joint drive ropes are connected to the second fixed plate in sequence through corresponding tensioning mechanisms and movable pulleys.

[0016] Preferably, a limiting plate is provided in the middle of the serpentine spring, and a limiting ring is provided between adjacent installations. The limiting ring has a limiting through hole, and the limiting plate is inserted into the limiting through hole.

[0017] Preferably, the gripping mechanism includes a gripper, which is mounted on a mounting plate of a spherical friction body located at the tail end via a connecting frame, and an image acquisition component is mounted on the connecting frame.

[0018] Preferably, it also includes a multi-stage longitudinal adjustment mechanism, which includes a first-stage stepped platform, a second-stage stepped platform, a third-stage stepped platform, and a fourth-stage stepped platform that are slidably arranged from the outside to the inside. A transmission electric cylinder is fixed inside the first-stage stepped platform, and a first transmission gear is installed on the telescopic end of the transmission electric cylinder. A second transmission gear is installed on the inner side of the second-stage stepped platform, and a third transmission gear is installed on the inner side of the third-stage stepped platform.

[0019] One end of the first transmission chain is fixed inside the first-level stepped platform, and the other end of the first transmission chain passes around the first transmission gear and the second transmission gear in sequence and is fixedly connected to the inside of the third-level stepped platform. The first transmission chain is distributed in an S-shape.

[0020] One end of the second transmission chain is fixed to the outside of the fourth-level stepped platform, and the other end of the second transmission chain passes around the third transmission gear and is fixedly connected to the inside of the second-level stepped platform. The second transmission chain is distributed in a U-shape.

[0021] The front and rear supports are installed at the top of the first-level stepped platform.

[0022] Therefore, the present invention employs the above-mentioned integrated continuous robotic arm for grasping, which has the following beneficial effects:

[0023] (1) A continuous joint with a serpentine spring and a spherical friction body is adopted, which realizes adjustable stiffness and significantly improves load capacity. Compared with the existing continuous variable stiffness joints, it has low cost. The stiffness of the continuous joint is adjusted by an electromagnetic stiffness adjustment component. The joint stiffness is flexibly adjustable through this coupling structure, and the load capacity is strong. The joint strength is greatly improved by the synergistic effect of the coupling of the serpentine spring and the spherical friction body. The overall structural strength is significantly enhanced, and thus it has better load bearing performance. It effectively solves the technical pain points of insufficient strength and limited load capacity of existing similar joints.

[0024] (2) This invention employs a chain drive motor and a chain joint adjustment motor working in tandem. The single-sided drive chain only has unidirectional bending characteristics, and its structural stiffness in the non-bending direction (the other three directions) is significantly higher than that of the robotic arm. When it is necessary to extend the working range of the robotic arm without end-effector bending, the chain joint adjustment motor drives the continuous arm to rotate, so that the bendable side of the single-sided drive chain faces upward. By utilizing the high stiffness characteristics of the non-bending direction of the single-sided drive chain, the working range of the robotic arm can be greatly expanded without affecting the end-effector execution accuracy.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the overall structure of an integrated continuous robotic arm for grasping according to the present invention;

[0027] Figure 2 is a schematic diagram of the drive mechanism structure of the present invention;

[0028] Figure 3 is a schematic diagram of the internal structure of the drive mechanism of the present invention;

[0029] Figure 4 is a schematic diagram of the coupled robotic arm structure of the present invention;

[0030] Figure 5 is a schematic diagram of the internal structure of the spherical friction body of the present invention;

[0031] Figure 6 is an exploded view of the spherical friction body of the present invention;

[0032] Figure 7 is a schematic diagram of the serpentine spring structure of the present invention;

[0033] Figure 8 is a schematic diagram of the gripping mechanism of the present invention;

[0034] Figure 9 is a schematic diagram of the tensioning mechanism of the present invention;

[0035] Figure 10 is a schematic diagram of the chain tensioning mechanism of the present invention;

[0036] Figure 11 is a top view of the multi-stage longitudinal adjustment mechanism of the present invention;

[0037] Figure 12 is a front view of the multi-stage longitudinal adjustment mechanism of the present invention.

[0038] Figure Labels

[0039] 1. Drive mechanism; 11. Fixed panel; 12. Chain joint adjustment motor; 13. Rear support; 14. Fixed plate; 15. Front support; 16. Rotating bracket; 161. First fixed plate; 162. Second fixed plate; 163. Third fixed plate; 164. L-shaped connector; 165. Length adjustment stud; 166. Polygonal fixing ring; 167. Slide table; 168. Moving pulley; 2. Coupled robotic arm body; 21. Flexible rod; 22. Limiting ring; 23. Spherical friction rod Friction body; 231, cross-shaped ball ring; 232, outer friction layer; 233, sliding ball ring; 234, middle friction layer; 235, connecting layer; 236, inner friction layer; 237, hollow cylinder; 238, ball-and-socket joint; 239, connecting piece; 2310, slide rail; 2311, mounting plate; 2312, through hole; 2313, slide groove; 24, serpentine spring; 241, limiting plate; 25, electromagnetic stiffness adjustment component; 251, electromagnetic coil; 252, permanent magnet; 26. Joint drive rope; 27. Chain joint drive rope; 3. Gripping mechanism; 31. Gripper; 32. Connecting frame; 33. Image acquisition component; 4. Tensioning mechanism; 41. Tensioning U-shaped frame; 42. Fixed reversing pulley; 43. Tensioning adjustment support; 44. Adjusting pulley; 45. Adjusting nut; 5. Chain tensioning mechanism; 51. Chain drive motor; 52. Chain drive housing; 53. Single-sided drive chain; 54. First bevel gear; 55. Second bevel gear; 56. First 57. Rotating shaft; 58. First transmission wheel; 59. Transmission belt; 50. Second rotating shaft; 510. Second transmission wheel; 511. Chain drive gear; 6. Multi-stage longitudinal adjustment mechanism; 61. First-stage stepped platform; 62. Second-stage stepped platform; 63. Third-stage stepped platform; 64. Fourth-stage stepped platform; 65. Transmission electric cylinder; 66. First transmission gear; 67. Second transmission gear; 68. Third transmission gear; 69. First transmission chain; 610. Second transmission chain. Detailed Implementation

[0040] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They 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. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" 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 can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] As shown in Figure 1, an integrated continuous robotic arm for grasping includes a drive mechanism 1, a coupled robotic arm body 2, and a grasping mechanism 3 connected in sequence.

[0043] As shown in Figure 2, the drive mechanism 1 includes a chain joint adjustment motor 12. The chain joint adjustment motor 12 is mounted on the rear support 13, and the drive cylinder is rotatably mounted on the front support 15 via the fixed plate 14. A rotating bracket 16 is provided between the front support 15 and the rear support 13 and is mounted on the fixed panel 11. The rotating bracket 16 includes a first fixed plate 161, a second fixed plate 162 and a third fixed plate 163. Several circumferentially distributed tensioning mechanisms 4 are provided between the first fixed plate 161 and the second fixed plate 162 on one side, as shown in Figure 9. The tensioning mechanism 4 includes a tensioning U-shaped frame 41. Fixed reversing pulleys 42 are symmetrically installed on the inner side of the tensioning U-shaped frame 41. An adjusting pulley 44 is installed on the bottom inner side of the tensioning U-shaped frame 41 via a tension adjusting support 43. An adjusting nut 45 is provided on the stud of the tension adjusting support 43. The tensioning U-shaped frame 41 is mounted on the second fixed plate 162. The position of the tension adjusting support 43 is adjusted by rotating the adjusting nut 45 to realize the adjustment of the tension of the drive rope on the coupled robotic arm 2. The second fixed plate 162 has several L-shaped connectors 164 (fixed by bolts) distributed circumferentially on the other side. One side of the third fixed plate 163 is connected to the output shaft of the chain joint adjusting motor 12. The output shaft of the chain joint adjusting motor 12 is mounted on the rear support 13 through bearings. The other side of the third fixed plate 163 is equipped with a polygonal fixing ring 166 through a length adjusting stud 165. The distance between the polygonal fixing ring 166 and the L-shaped connectors 164 is adjusted according to actual needs to accommodate slides 167 of different lengths. Several circumferentially distributed slides 167 are fixedly installed between the polygonal fixing ring 166 and the several L-shaped connectors 164, as shown in Figure 3. The slider inside the slide 167 is equipped with a movable pulley 168.

[0044] As shown in Figure 10, a chain tensioning mechanism 5 is provided inside the rotating bracket 16. The chain tensioning mechanism 5 includes a chain drive motor 51 mounted on the third fixed plate 163. The chain drive motor 51 is fixed to one end of the chain drive housing 52, and the output shaft of the chain drive motor 51 is connected to a single-sided drive chain 53 through a gear transmission assembly. The gear transmission assembly includes two meshing first bevel gears 54 and second bevel gears 55. The first bevel gear 54 is mounted on the output shaft of the chain drive motor 51, and the second bevel gear 55 is mounted on a first rotating shaft 56. The first rotating shaft 56 is rotatably mounted on the chain drive housing 52. Inside the first rotating shaft 56, a first transmission wheel 57 is mounted on the first rotating shaft 56. The first transmission wheel 57 is connected to a second transmission wheel 510 on the second rotating shaft 59 via a transmission belt 58. The second rotating shaft 59 is rotatably mounted inside the chain drive housing 52. A chain drive gear 511 is mounted on the second rotating shaft 59 and is connected to a single-sided transmission chain 53. One end of the single-sided transmission chain 53 is slidably mounted inside the chain drive housing 52, and the other end of the chain drive housing 52 is mounted on the first fixed plate 161. The other end of the single-sided transmission chain 53 passes through the chain drive housing 52 and is connected to one side of the fixed plate 14. When the robotic arm needs to perform a bending action, the single-sided transmission chain 53 is rotated to a preset angle suitable for the bending requirement by adjusting the chain joint motor 12. Then, the drive rope is driven by the control slide 167 to drive the robotic arm to bend in the preset direction. Relying on the high rigidity advantage of the other three directions of the single-sided chain, the working range of the robotic arm can be significantly improved while ensuring the stability of the end effector's accuracy.

[0045] As shown in Figure 4, the coupled robotic arm body 2 includes a flexible rod 21 and several spherical friction bodies 23 mounted on the flexible rod 21. The spherical friction bodies 23 are connected end-to-end in sequence, and circumferentially distributed serpentine springs 24 are arranged between adjacent spherical friction bodies 23. As shown in Figures 5-6, each spherical friction body 23 includes, from the outside to the inside, a cross-shaped ball ring 231, an outer friction layer 232, a sliding ball ring 233, a middle friction layer 234, a connecting layer 235, and an inner friction layer 236. The inner friction layer 236 has semi-hollow spherical shapes on its upper and lower sides and is connected to the connecting layer 235. The lower side of the connecting layer 235 is in contact with the inner friction layer 236, and the upper side of the connecting layer 235 is in contact with the lower side of the middle friction layer 234. The upper side of the connecting layer 235 has a hollow shape. A hollow cylinder 237 passes through a sliding ball ring 233 and connects to a ball-and-socket joint 238. Connecting pieces 239 are provided on both the middle friction layer 234 and the outer friction layer 232. The connecting pieces 239 are fixedly connected to the inner friction layer 236. The upper side of the middle friction layer 234 is in contact with the lower side of the sliding ball ring 233. The upper side of the sliding ball ring 233 is in contact with the lower side of the outer friction layer 232. The upper side of the outer friction layer 232 is in contact with a cross ball ring 231. The outer side of the cross ball ring 231 is in contact with the inner side of the ball-and-socket joint 238. A groove 2313 is provided on the upper side of the outer friction layer 232 and the inner side of the ball-and-socket joint 238. A slide rail 2310 is provided on both the inner and outer sides of the cross ball ring 231. The slide rail 2310 is located in the corresponding groove 2313. The inner surface of the cross-shaped ball ring 231 is provided with slide rails 2310 distributed along the X-axis, and the outer surface is provided with slide rails 2310 distributed along the Y-axis. These slide rails are adapted to the slide grooves 2313 of the outer friction layer 232 and the slide grooves 2313 of the ball-and-socket joint 238, respectively. The cross-shaped geometric structure in the field of vision only blocks the torsional degree of freedom (non-essential movement) around the robot's central Z-axis, but fully retains the two bending degrees of freedom (core working movements) around the X-axis (pitch) and around the Y-axis (yaw). A mounting plate 2311 is provided in the middle of the inner friction layer 236. A through hole 2312 is opened on the mounting plate 2311. The two ends of the serpentine spring 24 are fixed on the adjacent mounting plates 2311, as shown in Figure 7. A limit plate 241 is provided in the middle of the serpentine spring 24. A limit ring 22 is provided between adjacent mounting plates. The limit ring 22 has a limit through hole. The limit plate 241 is inserted into the limit through hole to limit the radial displacement of the serpentine spring 24. This allows the serpentine spring 24 to only undergo stretching or compression deformation along its axial direction, effectively limiting the radial (left-right) swaying displacement of the serpentine spring 24, ensuring that the motion trajectory of the serpentine spring 24 conforms to the preset design, and improving the stability and precision of joint movement.

[0046] The coupled robotic arm 2 is equipped with circumferentially distributed drive ropes, including two sets of joint drive ropes 26 and one set of chain joint drive ropes 27, with three drive ropes in each set. One end of each of the three chain joint drive ropes 27 is fixed to the mounting plate 2311 of the first spherical friction body 23 and is circumferentially distributed. One end of each of the three joint drive ropes 26 in each set is fixed to the mounting plate 2311 of the corresponding spherical friction body 23 and is circumferentially distributed, realizing two-level joint control. More joints can be divided according to actual control needs. The other ends of the joint drive ropes 26 and the chain joint drive ropes 27 are connected to the second fixed plate 162 in sequence through the corresponding tensioning mechanism 4 and the moving pulley 168. By controlling the movement of the corresponding drive ropes, the corresponding posture control of the coupled robotic arm 2 is achieved.

[0047] An electromagnetic stiffness adjustment component 25 is provided at the bottom of the coupled robotic arm body 2. The electromagnetic stiffness adjustment component 25 is used to adjust the friction force of several spherical friction bodies 23 to adjust the stiffness of the coupled robotic arm body 2. The electromagnetic stiffness adjustment component 25 includes an electromagnetic coil 251 and a permanent magnet 252 arranged in parallel. The electromagnetic coil 251 is installed on the other side of the fixed plate 14, and the permanent magnet 252 is in contact with the first spherical friction body 23. Variable stiffness adjustment can be achieved by using only a single electromagnetic coil 251, which greatly reduces manufacturing costs.

[0048] As shown in Figure 8, the gripping mechanism 3 includes a gripper 31, which is mounted on the mounting plate 2311 of the spherical friction body 23 located at the tail end via a connecting frame 32. An image acquisition component 33 is mounted on the connecting frame 32.

[0049] To increase the longitudinal travel in this embodiment, as shown in Figures 11-12, a multi-stage longitudinal adjustment mechanism 6 is also provided. The multi-stage longitudinal adjustment mechanism 6 includes a first-stage stepped platform 61, a second-stage stepped platform 62, a third-stage stepped platform 63, and a fourth-stage stepped platform 64 that are slidably arranged from the outside to the inside. A transmission cylinder 65 is fixed inside the first-stage stepped platform 61. A first transmission gear 66 is installed at the telescopic end of the transmission cylinder 65. A second transmission gear 67 is installed inside the second-stage stepped platform 62. A third transmission gear 68 is installed inside the third-stage stepped platform 63. One end of a first transmission chain 69 is fixed inside the first-stage stepped platform 61. The other end of the first transmission chain 69 passes around the first transmission gear 66 and the second transmission gear 67 in sequence and is fixedly connected to the inside of the third-stage stepped platform 63. The first transmission chain 69 is distributed in an S-shape. One end of the second transmission chain 610 is fixed to the outside of the fourth-level stepped platform 64, and the other end of the second transmission chain 610 passes around the third transmission gear 68 and is fixedly connected to the inside of the second-level stepped platform 62. The second transmission chain 610 is distributed in a U-shape, and the front support 15 and the rear support 13 are installed on the upper end of the first-level stepped platform 61. Adjacent layers are linked together by a chain transmission mechanism. The driving force output by the transmission cylinder 65 can drive the chain transmission mechanism of each layer to move sequentially, thereby driving each layer to extend and unfold in a preset direction, realizing long-distance power transmission and motion transmission of the continuous robotic arm. The stretch ratio of this four-layer structure can reach more than 3, which has efficient telescopic performance. At the same time, the overall structure is compact and small in size, which not only facilitates transportation and handling, but also adapts to a variety of installation scenarios, reduces the difficulty of fixed installation, and effectively meets the requirements of continuous robotic arms for long-distance transmission, high stretch ratio and compact structure.

[0050] The specific control process is as follows:

[0051] When the entire longitudinal feed motion of the robotic arm 2 needs to be coupled, the cylinder rod of the transmission cylinder 65 first extends, driving the first transmission gear 66 to move forward. The first transmission chain 69 moves forward, driving the third-level stepped platform 63 to move forward, with a movement distance ratio of 1:2. Simultaneously, the first transmission chain 69 drives the second transmission gear 67 to move, which in turn drives the second-level stepped platform 62, with a movement distance ratio of 1:1 between the second-level stepped platform 62 and the transmission cylinder 65. The movement of the third-level stepped platform 63 drives the third transmission gear 68 to move forward, which in turn drives the fourth-level stepped platform 64 to move forward via the second transmission chain 610. The movement distance ratio of the fourth-level stepped platform 64 to the third-level stepped platform 63 is 2:1, and the movement distance ratio of the fourth-level stepped platform 64 to the transmission cylinder 65 is 4:1. This causes the fixed panel 11 to move forward, which in turn drives the entire continuous robotic arm to move forward, thus achieving the coupled longitudinal feed motion of the entire robotic arm 2.

[0052] When the coupled robotic arm 2 needs to move longitudinally, the coupled robotic arm 2 first rotates as a whole, the chain joint adjustment motor 12 is energized, the rotating bracket 16 rotates, and then drives the entire coupled robotic arm 2 and the rotating bracket 16 to rotate. When the bending direction of the single-sided transmission chain 53 is opposite to the force direction of the coupled robotic arm 2, the chain joint adjustment motor 12 stops rotating, thereby improving the load-bearing capacity during movement. After the coupled robotic arm 2 reaches its position, the chain drive motor 51 is energized. The output shaft of the chain drive motor 51 rotates, driving the first bevel gear 54 to rotate. The first bevel gear 54 drives the second bevel gear 55 to rotate. Through the first rotating shaft 56 (two-stage stepped shaft), the first transmission wheel 57 rotates synchronously. The first transmission wheel 57 drives the second transmission wheel 510 to rotate through the transmission belt 58. The second transmission wheel 510 drives the chain drive gear 511 to rotate through the second rotating shaft 59 (three-stage stepped shaft). The chain drive gear 511 meshes with the single-sided transmission chain 53, causing the single-sided transmission chain 53 to slide in the chain drive groove inside the chain drive housing 52. The single-sided transmission chain 53 extends out of the chain drive housing 52, and the coupled robotic arm 2 moves forward. The sliders of all the slides 167 in the drive mechanism 1 move synchronously, ensuring that the two sets of joint drive ropes 26 and chain joint drive ropes are stretched synchronously. The ratio of the single-sided transmission chain 53 to the slider movement distance is 2:1, ensuring that the rope stretching length is sufficient even with a small stroke.

[0053] When the coupled robotic arm 2 bends to grasp, according to the posture of the coupled robotic arm 2, the slide 167 corresponding to the chain joint drive rope 27 is controlled to move forward or backward proportionally to ensure that the chain joint moves into position. The slide 167 of the two sets of joint drive ropes 26 is controlled to move forward or backward proportionally to ensure that the first joint bends into position and the second joint bends into position, so that the coupled robotic arm 2 reaches a fixed posture. After all the above movements are completed, the gripper 31 grasps under the drive of the motor.

[0054] When the stiffness of the coupled robotic arm 2 needs to be varied, since the flexible rod 21 (rubber material) is fixed at both ends and its length remains unchanged, when the electromagnetic coil 251 is energized, a repulsive force is generated between the electromagnetic coil 251 and the permanent magnet 252, which compresses the joints of the robotic arm. During compression, the friction generated by the multiple friction layers works together to lock the spherical friction body. By adjusting the magnitude of the current, the stiffness of the coupled robotic arm 2 can be controlled. When not energized, the spherical friction body 23 maintains a state of low resistance and can be smoothly pulled.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated continuous robotic arm for grasping, characterized in that: The system includes a drive mechanism, a coupled robotic arm, and a gripping mechanism connected in sequence. The coupled robotic arm has circumferentially distributed drive ropes. The arm includes a flexible rod and several spherical friction elements mounted on the flexible rod. These spherical friction elements are connected end-to-end, and circumferentially distributed serpentine springs are positioned between adjacent elements. An electromagnetic stiffness adjustment component is located at the bottom of the coupled robotic arm, used to adjust the frictional force of the spherical friction elements to adjust the stiffness of the coupled robotic arm. The drive mechanism includes a chain joint adjustment motor mounted on a rear support, and a drive cylinder rotated on a front support via a fixed disc. A rotating bracket is provided between the front and rear supports on the seat. The rotating bracket includes a first fixed plate, a second fixed plate, and a third fixed plate. Several circumferentially distributed tensioning mechanisms are provided between the first and second fixed plates on one side. Several L-shaped connectors are circumferentially distributed on the other side of the second fixed plate. One side of the third fixed plate is connected to the output shaft of the chain joint adjustment motor. A polygonal fixing ring is installed on the other side of the third fixed plate through a length adjustment stud. Several circumferentially distributed slides are fixedly installed between the polygonal fixing ring and the several L-shaped connectors. A movable pulley is installed on the slider inside the slide. A chain tensioning mechanism is provided inside the rotating bracket. The tensioning mechanism includes a tensioning U-shaped frame. The tensioning U-shaped frame has symmetrically installed fixed reversing pulleys on its inner side. An adjusting pulley is installed at the bottom inner side of the tensioning U-shaped frame via a tension adjusting support. An adjusting nut is provided on the stud of the tension adjusting support. The tensioning U-shaped frame is mounted on the second fixed plate. The chain tensioning mechanism includes a chain drive motor mounted on the third fixed plate. The chain drive motor is fixed to one end of the chain drive housing, and its output shaft is connected to a single-sided drive chain via a gear transmission assembly. The gear transmission assembly includes two meshing first bevel gears and a second bevel gear. The first bevel gear is mounted on the output shaft of the chain drive motor, and the second bevel gear is mounted on a first rotating shaft. The first rotating shaft is rotatably mounted on... Inside the chain drive housing, a first drive wheel is mounted on a first rotating shaft. The first drive wheel is connected to a second drive wheel on a second rotating shaft via a drive belt. The second rotating shaft is rotatably mounted inside the chain drive housing. A chain drive gear is mounted on the second rotating shaft and is connected to a single-sided drive chain. One end of the single-sided drive chain is slidably mounted inside the chain drive housing, and the other end of the chain drive housing is mounted on a first fixed plate. The other end of the single-sided drive chain passes through the chain drive housing and is connected to one side of the fixed plate. The electromagnetic stiffness adjustment assembly includes an electromagnetic coil and a permanent magnet arranged in parallel. The electromagnetic coil is mounted on the other side of the fixed plate, and the permanent magnet is in contact with the spherical friction body located at the first position.

2. The integrated continuous robotic arm for grasping according to claim 1, characterized in that: The spherical friction body comprises, from the outside to the inside, a cross-shaped ball ring, an outer friction layer, a sliding ball ring, a middle friction layer, a connecting layer, and an inner friction layer. The upper and lower sides of the inner friction layer are semi-hollow spheres connected to the connecting layer. The lower side of the connecting layer is in contact with the inner friction layer, and the upper side of the connecting layer is in contact with the lower side of the middle friction layer. A hollow cylinder is located on the upper side of the connecting layer, passing through the sliding ball ring and connecting to a ball-and-socket joint. Connecting pieces are provided on both the middle and outer friction layers, and these connecting pieces are fixedly connected to the inner friction layer. Next, the upper side of the middle friction layer is attached to the lower side of the sliding ball ring, the upper side of the sliding ball ring is attached to the lower side of the outer friction layer, the upper side of the outer friction layer is attached to the cross ball ring, the outer side of the cross ball ring is attached to the inner side of the ball-and-socket joint, and the upper side of the outer friction layer and the inner side of the ball-and-socket joint are both provided with grooves, and the inner and outer sides of the cross ball ring are both provided with slide rails, which are set in the corresponding grooves; a mounting plate is provided in the middle of the inner friction layer, and a through hole is opened on the mounting plate. The two ends of the serpentine spring are respectively fixed on the adjacent mounting plates.

3. The integrated continuous robotic arm for grasping according to claim 2, characterized in that: The drive rope includes at least one set of joint drive ropes and chain joint drive ropes; one end of several chain joint drive ropes is fixed to the mounting plate of the first spherical friction body and is circumferentially distributed; one end of at least three joint drive ropes in each set is fixed to the mounting plate of the corresponding spherical friction body and is circumferentially distributed; the other ends of the chain joint drive ropes and joint drive ropes are connected to the second fixed plate in sequence through the corresponding tensioning mechanism and the movable pulley.

4. The integrated continuous robotic arm for grasping according to claim 3, characterized in that: A limit plate is provided in the middle of the serpentine spring, and a limit ring is provided between adjacent mounting plates. The limit ring has a limit through hole, and the limit plate is inserted into the limit through hole.

5. The integrated continuous robotic arm for grasping according to claim 4, characterized in that: The gripping mechanism includes grippers that are mounted on a mounting plate of a spherical friction body located at the tail end via a connecting frame. An image acquisition component is mounted on the connecting frame.

6. The integrated continuous robotic arm for grasping according to claim 5, characterized in that: It also includes a multi-stage longitudinal adjustment mechanism, comprising a first-stage stepped platform, a second-stage stepped platform, a third-stage stepped platform, and a fourth-stage stepped platform that slide sequentially from the outside to the inside. A transmission cylinder is fixed inside the first-stage stepped platform, and a first transmission gear is installed at the telescopic end of the transmission cylinder. A second transmission gear is installed on the inner side of the second-stage stepped platform, and a third transmission gear is installed on the inner side of the third-stage stepped platform. One end of the first transmission chain is fixed inside the first-stage stepped platform, and the other end of the first transmission chain passes around the first and second transmission gears and is fixedly connected to the inner side of the third-stage stepped platform. The first transmission chain is S-shaped. One end of the second transmission chain is fixed to the outside of the fourth-stage stepped platform, and the other end of the second transmission chain passes around the third transmission gear and is fixedly connected to the inner side of the second-stage stepped platform. The second transmission chain is U-shaped. A front support and a rear support are installed at the top of the first-stage stepped platform.

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