A robotic arm with adjustable local stiffness

Abstract

The present invention discloses a mechanical arm with adjustable local stiffness, comprising multiple tensioning members movably connected in sequence; multiple tensioning members are provided with tensioning through holes, and a locking member is clamped in any tensioning through hole, and the tensioning through hole is slidably connected to the locking member; the locking member comprises a sleeve and a reversing rod; the reversing rod is coaxially sleeved in the sleeve, and the reversing rod is rotatably connected to the sleeve, and both ends of the reversing rod are provided with a tensioning rope and a tensioning hole clamping block; the two tensioning ropes pass through the tensioning through holes on adjacent tensioning members respectively; the tensioning rope is used to drive the locking member to move in or out of the tensioning through hole to rotate the reversing rod; the rotation of the reversing rod is used to drive the tensioning hole clamping block to be selectively clamped outside the tensioning through hole, and the locking member with the function of sliding and clamping in the tensioning through hole can control the displacement change of the locking member by pulling the tensioning rope, and the rope fixed position has been arranged before applying the pre-tensioning force, so that the local stiffness characteristics of the rope-driven tensioning integral robot can be regulated.

Description

Technical Field

[0001] The present invention relates to the technical field of robotic arms, and in particular to a robotic arm with adjustable local stiffness. Background Art

[0002] Tensegrity structures, composed of rigid rods that bear tension and compression, and flexible cables that bear tension, offer new insights into the design of continuum robots. Typical tensegrity robots are capable of rolling, crawling, and grasping. Tensegrity-based robotic arms have become a research hotspot. In most applications, the arm must be able to move flexibly and smoothly while maintaining a stable and controllable posture. Therefore, controlling the structural stiffness of tensegrity robotic arms is crucial.

[0003] The structural stiffness control of existing tensegrity manipulators mainly adopts the antagonistic variable stiffness method, which means applying two driving forces in opposite directions on the same target to increase the overall stiffness in a tensioning manner. This method is widely used in the stiffness control of manipulators based on tensegrity structures. Existing research has found that if asymmetric displacement changes on both sides of the tensioning rope can be achieved, the stiffness characteristics of the flexible robot will be related to the tension of the driving rope.

[0004] However, existing structures can usually only change the tightness of the tensioning rope to achieve stiffness adjustment of this part, that is, it is impossible to achieve asymmetric displacement changes on both sides of the tensioning rope, so it is impossible to arrange the rope fixed position before applying pre-tensioning force, and thus it is impossible to directly adjust the stiffness characteristics of this part by changing the tension of the drive rope.

[0005] Therefore, it is of great application value to study a robotic arm with adjustable local stiffness that can achieve asymmetric displacement changes on both sides of the tensioning rope. Summary of the Invention

[0006] The object of the present invention is to provide a robotic arm with adjustable local stiffness, so as to solve the problem that the existing robotic arm cannot achieve asymmetric displacement changes on both sides of the tensioning rope.

[0007] In order to solve the above technical problems, the present invention provides a mechanical arm with adjustable local stiffness, comprising a plurality of tensioning members, locking members and tensioning ropes that are movably connected in sequence; each of the tensioning members is provided with a tensioning through-hole, and the locking member is configured to pass through the tensioning through-hole; the tensioning rope passes through the tensioning through-hole, and the tensioning rope is used to drive the locking member so that the locking member is partially moved into the tensioning through-hole of any of the tensioning members; the locking member comprises a sleeve and a reversing rod; the sleeve is sleeved outside the reversing rod, and the reversing rod is rotatably connected to the sleeve; tensioning hole blocks are provided at both ends of the reversing rod, and the two tensioning hole blocks are arranged alternately , the rotation of the reversing rod is configured to require an actuating force to drive; when the tension of the tensioning rope is less than the actuating force of the reversing rod, at least one of the tensioning hole blocks is stuck outside the tensioning through hole; when the tension of the tensioning rope is greater than the actuating force of the reversing rod, the reversing rod rotates to allow the tensioning hole block stuck outside the tensioning through hole to enter or pass through the tensioning through hole. The locking member with the sliding and clamping functions in the tensioning through hole can control the displacement change of the locking member by pulling the tensioning rope. The rope fixed position has been arranged before applying the pre-tensioning force, and the local stiffness characteristics of the rope-driven tensioning integral robot can be regulated.

[0008] In one embodiment, a reversing groove is provided on the inner wall of the sleeve, and the reversing groove has at least one inclined section; a reversing slider is provided on the outer wall of the reversing rod, and the reversing slider can be slidably placed in the inclined section. The reversing groove with an inclined section can convert the vertical pulling of the tensioning rope into a circumferential rotation of the reversing rod, thereby driving the tensioning hole card block to rotate, so as to achieve the purpose of clamping the tensioning hole card block or matching it with the tensioning through hole.

[0009] In one embodiment, the plurality of inclined segments are circumferentially arranged around the axis of the sleeve, the plurality of inclined segments are staggered, and the plurality of inclined segments are connected end to end, so as to realize unidirectional rotation of the reversing rod.

[0010] In one embodiment, the number of the inclined segments is at least four, and the stroke of at least any two of the inclined segments is used to control the reversing rod to rotate 90°. The 90° rotation function facilitates the control of the rotation of the tensioning hole card block.

[0011] In one embodiment, a return spring is provided between the tensioning hole block and the sleeve, and the return spring is coaxially sleeved outside the reversing rod. On the one hand, the return spring can enhance the unidirectional rotation function of the reversing slider, and on the other hand, it can increase the actuating force of the device.

[0012] In one embodiment, the shape of the tensioning hole block and the shape of the tensioning through hole are both elliptical, and the contact cross-section between the tensioning hole block and the tensioning rope is elliptical, which is conducive to the rotation of the reversing rod.

[0013] In one embodiment, the tensioning rope includes a plurality of tensioning ropes; the plurality of tensioning ropes are fixedly connected to the sleeve, and the plurality of tensioning ropes are tied together to form a supporting space, and the tensioning hole card block is arranged in the supporting space.

[0014] In one embodiment, the plurality of tensioning ropes are in contact with the two tensioning hole card blocks to increase the friction between the two.

[0015] In one embodiment, a rope winding mechanism is further included, and the rope winding mechanism includes a rope winding drum; the two ends of the tensioning rope are respectively fixedly connected to the rope winding drum, and the rope winding mechanism controls the retraction and release of the tensioning rope to achieve the displacement change of the locking member on the tensioning through hole, so that the rope arrangement can be automatically completed, avoiding the situation where manual adjustment of the rope arrangement at each location is required.

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

[0017] Since a locking piece is provided in the tensioning through hole, the locking piece includes a reversing rod and a sleeve, and a tensioning rope is also provided at the end of the reversing rod, the tensioning rope can pull the entire locking piece to selectively move in or out of any tensioning through hole on the same side during application. When a downward pulling force is applied to the locking piece (when the pulling force is less than the actuating force), the locking piece partially moves into the tensioning through hole. Since a tensioning hole block is provided at the end of the reversing rod, the tensioning hole block at the top will be stuck outside the tensioning through hole, thereby realizing the rope arrangement on the bottom side, that is, the asymmetric displacement change of the bottom side, similar to Similarly, when the direction of the asymmetric displacement needs to be changed, the tensioning rope continues to pull the reversing rod downward (when the tension is greater than the actuating force), which will cause the reversing rod to rotate circumferentially until the tensioning hole block at the bottom can be stuck outside the tensioning hole. Subsequently, the tensioning rope is pulled in the opposite direction to move the entire locking piece upward and stuck in the tensioning hole, realizing the rope arrangement on the top side, that is, the asymmetric displacement change on the top side. The rope fixed position has been arranged before the pre-tensioning force is applied, which can regulate the local stiffness characteristics of the rope-driven tensioning integral robot.

[0018] And since the locking piece can be selectively clamped in any tensioning hole, when the stiffness of the arm segment of a specified robotic arm needs to be adjusted, the tensioning rope can be pulled to move the locking piece to the tensioning hole at the specified position. Subsequently, the rope arrangement at the specified position can be achieved by rotating, adjusting and clamping the tensioning hole clamping block on the tensioning hole, thereby achieving an asymmetric displacement change at the position, and then achieving stiffness control at the position.

[0019] In summary, regardless of the top or bottom rope arrangement, the fixed position of the rope has been asymmetrically displaced before the pre-tensioning force is applied, which can regulate the stiffness characteristics of the rope-driven tensegrity robot, completely changing the problem of the inability to achieve asymmetric displacement changes of the tensioned rope in existing technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic diagram of the overall structure provided by the preferred embodiment of the present invention;

[0022] Figure 2 1 is a schematic structural diagram of a locking member provided in a preferred embodiment of the present invention;

[0023] Figure 3 is a schematic cross-sectional view of a locking member provided in a preferred embodiment of the present invention;

[0024] Figure 4 is a schematic cross-sectional structural diagram of a sleeve provided in a preferred embodiment of the present invention;

[0025] Figure 5 1 is a schematic diagram of the expansion of the reversing slot provided in the preferred embodiment of the present invention;

[0026] Figure 6-1 This is a schematic diagram of the rope arrangement process provided by the preferred embodiment of the present invention. Figure 1 ;

[0027] Figure 6-2 This is a schematic diagram of the rope arrangement process provided by the preferred embodiment of the present invention. Figure 2 ;

[0028] Figure 6-3 This is a schematic diagram of the rope arrangement process provided by the preferred embodiment of the present invention. Figure 3 ;

[0029] Figure 6-4 This is a schematic diagram of the rope arrangement process provided by the preferred embodiment of the present invention. Figure 4 .

[0030] The reference numerals are as follows:

[0031] 1. Tensioning member; 10. Tensioning through hole;

[0032] 2. Locking member; 20. Sleeve; 200. Reversing slot; 2000. Inclined section; 21. Reversing rod; 210. Tensioning hole block; 211. Reversing slider; 22. Return spring;

[0033] 3. Tensioning rope; 30. Tensioning rope. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] Tensegrity structures, composed of rigid rods that bear tension and compression, and flexible cables that bear tension, offer new insights into the design of continuum robots. Typical tensegrity robots are capable of rolling, crawling, and grasping. Tensegrity-based robotic arms have become a research hotspot. In most applications, the arm must be able to move flexibly and smoothly while maintaining a stable and controllable posture. Therefore, controlling the structural stiffness is crucial.

[0036] In the existing technology, there are two major problems with the tensegrity robot arm. One is that it is impossible to achieve asymmetric displacement changes of the tensioning rope, that is, it is impossible to adjust the rope arrangement. Specifically, the existing technology adjusts the local stiffness of the robot arm, usually by directly pulling the connecting tensioning rope of the local structure, and adjusting the local stiffness of the robot arm by tightening and loosening the rope. It is impossible to directly associate the tensioning force of the drive rope with the stiffness characteristics of the robot arm; the second is that the rope arrangement in the existing technology is still manually operated, that is, when the rope arrangement of a certain arm section needs to be adjusted, the position of the rope needs to be manually controlled, which is time-consuming and labor-intensive.

[0037] In order to solve the above problems, the present invention provides a robotic arm with adjustable local stiffness, which is designed in two major directions. One is to open a tensioning hole 10 on the tensioning member 1 and a locking member 2 that can be moved in and out of the tensioning hole 10 or stuck outside the tensioning hole 10, so as to realize the asymmetric displacement change of the tensioning rope; the other is to fix the tensioning rope 3 with the rope winding mechanism. Through the pulling of the rope winding mechanism, when the tension of the tensioning rope 3 is greater than the actuating force of the reversing rod 21, it will drive the locking member 2 to move and rotate, thereby realizing the asymmetric displacement change of the tensioning rope 3.

[0038] For details, please refer to Figures 1 to 5, including a tensioning member 1 hinged by a connecting rod in sequence, a tensioning through-hole 10 and a locking member 2 on the tensioning member 1, and a tensioning rope 3 provided at both ends of the locking member 2. By pulling the tensioning rope 3, the movement and fixation of the locking member 2 in the tensioning through-hole 10 are controlled, thereby realizing the asymmetric displacement change of the tensioning rope. Before applying the pre-tensioning force, the fixed position of the rope has been asymmetrically displaced and arranged, which can regulate the stiffness characteristics of the rope-driven tensegrity robot.

[0039] In the embodiment of the present application, regarding the tensioning member 1, please refer to Figure 1 The tensioning member 1 includes two oppositely arranged tensioning springs and two oppositely arranged tensioning rods. The two ends of the tensioning springs are fixedly connected to the adjacent tensioning rods to form a rectangular tensioning structure. On one side close to the tensioning spring, the tensioning rod is hinged to the long tension rod on the other tensioning member 1 through an inclined rod to form the entire tensioning mechanical arm structure.

[0040] For the tensioning rod, a tensioning through hole 10 is provided on the tensioning rod. The groove direction of the tensioning through hole 10 is consistent with the length direction of the entire tensioning mechanical arm. The tensioning through hole 10 is used to clamp the locking piece 2. After adopting this setting method, the asymmetric displacement change of the locking piece 2 can be achieved through the movement and coordination of the locking piece 2 and the tensioning through hole 10.

[0041] In the embodiment of the present application, regarding the above-mentioned locking member 2, please refer to Figures 2 to 5 As shown, the locking member 2 includes a sleeve 20 and a reversing rod 21. The sleeve 20 is clamped in the tensioning through hole 10 of the middle tensioning member 1. The sleeve 20 is slidably connected to the tensioning through hole 10. The reversing rod 21 is coaxially sleeved in the sleeve 20. The reversing rod 21 is rotatably connected to the sleeve 20. Both ends of the reversing rod 21 are provided with a tensioning rope 3 and a tensioning hole block 210. After adopting this setting method, the sleeve 20 is limited by the tensioning through hole 10. Except for the tensioning rope 3 pulling the sleeve 20 up and down, it cannot rotate circumferentially, providing a structural basis for the rope-driven rotation of the reversing rod 21.

[0042] In some embodiments of this application, please refer to Figure 1 The shapes of the sleeve 20 and the tensioning hole 10 match each other, and the cross-sectional shapes of the sleeve 20 and the tensioning hole 10 are both rectangular. After adopting this setting method, the sleeve 20 can only move in the up and down directions and cannot rotate in the circumferential direction, thereby achieving the purpose of limiting the degree of freedom.

[0043] In some embodiments of this application, please refer to Figure 3 and Figure 4, a reversing slot 200 is provided on the inner wall of the sleeve 20, and the reversing slot 200 has at least one inclined section 2000; and a reversing slider 211 is provided on the outer wall of the reversing rod 21, and the reversing slider 211 can be slidably placed in the inclined section 2000. After adopting this setting method, the reversing slider 211 can slide in the inclined section 2000. When the tensioning hole card block 210 is stuck outside the tensioning through hole 10, the rope pulls the reversing rod 21. When the tensioning rope When the triggering tension of the rope 3 is greater than the actuating force of the reversing rod 21, the reversing rod 21 will convert the vertical tension of the rope into the force of the circular motion of the reversing rod 21, thereby realizing the reversing purpose of converting the vertical movement into the circular rotation, thereby adjusting the relative position of the tensioning hole card block 210 and the tensioning through hole 10, and meeting the user's need to clamp the tensioning hole card block 210 outside the tensioning through hole 10 or move the tensioning hole card block 210 into the tensioning through hole 10.

[0044] It should be noted that if the triggering tension of the tensioning rope 3 is smaller than the actuating force of the reversing rod 21 , the reversing rod 21 cannot be driven to rotate.

[0045] In some embodiments of this application, please refer to Figure 5 , multiple inclined sections 2000 are arranged circumferentially around the axis of the sleeve 20, multiple inclined sections 2000 are arranged in an staggered manner, and multiple inclined sections 2000 are connected end to end to form multiple V-shaped groove structures. After adopting this arrangement, when the tensioning rope 3 pulls the reversing rod 21 to move, it will drive the reversing slider 211 from the bottom end of the reversing slot 200 (that is, the bottom of the V-shape) to move to the top end of the reversing slot 200 (that is, the top of the V-shape), and then relax the rope, and the reversing slider 211 will move from the top end of the reversing slot 200 to the bottom end of the other reversing slot 200, realizing the unidirectional rotation of the reversing rod 21.

[0046] For details, please refer to Figure 5, the four inclined sections 2000 are arranged circumferentially around the axis of the sleeve 20, and the reversing slider 211 is used to realize the rotation of the reversing rod 2190° in the stroke of the two inclined sections 2000. After adopting this arrangement, for example, when the top tensioning hole card block 210 is clamped outside the tensioning through hole 10, and the length direction of the tensioning hole card block 210 is perpendicular to the length direction of the tensioning through hole 10, the reversing rod 21 is pulled downward, and the reversing slider 211 of the reversing rod 21 first moves from the bottom end of the reversing slot 200 (i.e., the V-shaped The reversing slider 211 moves from the top of the reversing slot 200 to the bottom of the other reversing slot 200. During this process, the reversing rod 21 and the sleeve 20 rotate 90°, and the tensioning hole card block 210 also rotates 90°. At this point, the tensioning hole card block 210 can pass through the tensioning through hole 10, realizing a longer asymmetric displacement arrangement, and regulating the stiffness characteristics of the rope-driven tensioning integral robot.

[0047] In addition, the tensioning hole card block 210 can be clamped outside the tensioning through hole 10 or inserted into the tensioning through hole 10 through the rotation of the reversing rod 21. Through the rotation cooperation of the reversing rod 21, the entire locking part 2 can be moved to the tensioning through hole 10 at the specified position, and the ropes of the mechanical arm section at the specified position can be pre-arranged to facilitate subsequent stiffness adjustment.

[0048] Further, in order to increase the actuating force to drive the reversing rod to rotate, please refer to Figure 2 A return spring 22 is provided between the tensioning hole card block 210 and the sleeve 20, and the return spring 22 is sleeved on the wall surface of the reversing rod 21. After adopting this setting method, on the one hand, the setting of the return spring 22 makes the actuating force for driving the reversing rod 21 to rotate greater, that is, a greater trigger force is required to rotate the reversing rod 21; on the other hand, when the reversing slider 211 moves from the bottom end of the reversing slot 200 (that is, the bottom of the V-shape) to the top end of the reversing slot 200 (that is, the top of the V-shape), the rope is loosened, and under the action of the restoring force of the return spring 22, the reversing slider 211 will move from the top end of the reversing slot 200 to the bottom end of the other reversing slot 200, thereby realizing the function of increasing the actuating force for driving the reversing rod 21 to rotate.

[0049] In some embodiments of this application, please refer to Figure 1 The shape of the tensioning hole card block 210 and the shape of the tensioning through hole 10 are both elliptical. After adopting this setting method, the contact cross-section of the tensioning hole card block 210 and the tensioning rope 3 is elliptical, which is conducive to the rotation of the reversing rod 21. Moreover, the tensioning hole card block 210 and the tensioning through hole 10 with matching shapes also facilitate the cooperation between the two.

[0050] In some embodiments of this application, please refer to Figure 2 The two tensioning hole card blocks 210 at both ends of the reversing rod 21 are arranged alternately, and when in use, at least one tensioning hole card block 210 will be kept misaligned with the tensioning through hole 10. After adopting this setting method, when one tensioning hole card block 210 is matched with the tensioning through hole 10 through the rotation and reversing of the reversing rod 21, the tensioning hole card block 210 can pass into or out of the tensioning through hole 10. However, the other tensioning hole card block 210 will be stuck outside the tensioning through hole 10 due to the misalignment with the tensioning through hole 10, thereby fixing and preventing the entire locking member 2 from falling out of the tensioning through hole 10.

[0051] Specifically, the staggered angle of the two tensioning hole card blocks 210 is 90°, that is, the two are staggered and arranged perpendicular to each other to match the arrangement of the reversing slots 200.

[0052] In the embodiment of the present application, regarding the tensioning rope 3, please refer to Figure 1 The tensioning rope 3 passes through the tensioning through-hole of the adjacent tensioning member. The tensioning rope 3 includes four tensioning ropes 30. The four tensioning ropes 30 are fixedly connected to the four corners of the sleeve. The four tensioning ropes 30 will not hinder the rotation of the locking member 2. The four tensioning ropes 30 are tied to each other to form a supporting space. The locking member 2 is arranged in the supporting space. After adopting this setting method, the tensioning force of the tensioning rope 30 will pass through the locking member 2. When the tensioning hole block 210 is stuck outside the tensioning through-hole 10, when the triggering tension of the tensioning rope 3 is greater than the actuating force of the reversing rod 21, it will drive the reversing rod 21 to rotate, which is conducive to the rotation of the reversing rod 21.

[0053] In some embodiments of this application, please refer to Figure 1 The supporting space is a conical supporting space, and the two tensioning hole card blocks 210 are respectively clamped at the two narrowed parts of the conical supporting space. The multiple tensioning ropes 30 are all in contact with the two tensioning hole card blocks 210 at both ends of the reversing rod 21. After adopting this setting method, the tensioning hole card block 210 will further increase the contact area with the tensioning rope 30, so that the contact between the tensioning hole card block 210 and the tensioning rope 30 is more complete, which is conducive to the rotation of the reversing rod 21.

[0054] It should be noted that the knots at both ends are at the same distance from the tensioning hole card block 210, that is, they are symmetrically distributed with the sleeve 20 as the center, so as to eliminate the torsional moment generated by traction.

[0055] Furthermore, in order to avoid manual participation in the arrangement of the ropes, the present solution also includes a rope winding mechanism, which has a rope winding drum, and the two ends of the tensioning rope 3 are fixedly connected to the rope winding drum. After adopting this setting method, when it is necessary to arrange the rope at a certain designated position, the rope winding mechanism pulls the locking member 2 to the designated position, and then controls the retraction and release of the tensioning rope 3 to achieve the displacement change of the locking member 2 on the tensioning through hole 10, so that the rope arrangement can be completed automatically, avoiding the need for manual adjustment of each rope arrangement.

[0056] It should be pointed out that the rope winding mechanism is a rope winding machine driven by a motor, and the lengths of the two ends of the rope winding machine are equal. During the entire adjustment process, only the motor movement is involved in the entire rope arrangement process, and there is no unnecessary manual operation.

[0057] The basic structure and principle of this solution can be known from the above, which will be described below in conjunction with the application.

[0058] The following example takes the entire locking member 2 as an example to move to the designated arm section and complete the rope arrangement. Figure 6-1 to Figure 6-4 .

[0059] First, if Figure 6-1 As shown, the rope winding mechanism is controlled, and the tensioning rope 3 pulls the entire locking member 2 to the designated tensioning hole 10. Since the tensioning hole block 210 at the bottom matches the shape of the tensioning hole 10, the tensioning hole block 210 at the bottom can pass directly through the tensioning hole 10. During this process, the triggering force is less than the actuating force, so the reversing rod 21 will not rotate.

[0060] Then, if Figure 6-2 As shown, when the top tensioning hole card block 210 abuts against the tensioning through hole 10, since the top tensioning hole card block 210 and the bottom tensioning hole card block 210 are staggered with each other, the top tensioning hole card block 210 and the tensioning through hole 10 are staggered at 90 degrees, and the top tensioning hole card block 210 will not be able to pass through the hole. Figure 6-3 As shown, when the tensioning rope 3 continues to pull the locking piece 2, since the trigger force is greater than the actuating force, combined with the friction contact between the tensioning rope 3 and the tensioning hole card block 210, the reversing slider 211 of the reversing rod 21 will start to move in the reversing slot 200, that is, the reversing slider 211 moves from the bottom end of the reversing slot 200 (that is, the bottom of the V-shape) to the top end of the reversing slot 200 (that is, the top of the V-shape). At this time, the tensioning rope 3 is relaxed, and under the action of the elastic restoring force of the reset spring 22, the reversing slider 211 will move from the top end of the reversing slot 200 to the bottom end of the other reversing slot 200. During this process, the entire reversing rod 21 and the sleeve 20 just rotate 90°, and the top tensioning hole card block 210 just matches the shape of the tensioning through hole 10, and the top tensioning hole card block 210 can pass through the tensioning through hole 10.

[0061] Finally, if Figure 6-4 As shown, the locking piece 2 is pulled upward until the tensioning hole block 210 at the bottom abuts against the tensioning through hole 10. Since the tensioning hole block 210 and the tensioning through hole 10 are staggered at 90 degrees, the tensioning hole block 210 at the bottom cannot pass through the tensioning through hole 10. Then the rope winding mechanism keeps the trigger force smaller than the actuating force, and the tensioning rope 3 is not loosened to fix the node and realize the arrangement of the rope.

[0062] It should be pointed out that the above is only the arrangement of the ropes for upward fixation. Similarly, the arrangement of the ropes for downward fixation can achieve the desired function through reverse movement, which will not be elaborated here.

[0063] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A robotic arm with adjustable local stiffness, comprising a plurality of tensioning members movably connected in sequence; It is characterized by: Also included are a locking member and a tensioning rope; The tensioning members are each provided with a tensioning through hole, and the locking member is configured to pass through the tensioning through hole; The tensioning rope passes through the tensioning through hole, and the tensioning rope is used to drive the locking member so that the locking member is partially moved into the tensioning through hole of any tensioning member; The locking member includes a sleeve and a reversing rod; The sleeve is sleeved outside the reversing rod, and the reversing rod is rotatably connected to the sleeve; Both ends of the reversing rod are provided with tensioning hole card blocks, and the two tensioning hole card blocks are arranged alternately. The rotation of the reversing rod is configured to require an actuating force to drive; When the tension of the tensioning rope is less than the actuating force of the reversing rod, at least one of the tensioning hole clamping blocks is clamped outside the tensioning through hole; When the tension of the tensioning rope is greater than the actuating force of the reversing rod, the reversing rod rotates to allow the tensioning hole block disposed outside the tensioning hole to enter or pass through the tensioning hole; A reversing slot is provided on the inner wall of the sleeve, and the reversing slot has at least one inclined section; A reversing slider is provided on the outer wall of the reversing rod, and the reversing slider is slidably placed in the inclined section; The tensioning rope includes a plurality of tensioning ropes; A plurality of tensioning ropes are fixedly connected to the sleeve, and the plurality of tensioning ropes are bound together to form a supporting space, and the tensioning hole card block is arranged in the supporting space.

2. The robotic arm according to claim 1, wherein: The plurality of inclined sections are arranged along the axis of the sleeve, the plurality of inclined sections are arranged in a staggered manner, and the plurality of inclined sections are connected end to end.

3. The robotic arm according to claim 2, wherein: The number of the inclined sections is at least four.

4. The robotic arm according to claim 1, wherein: A return spring is provided between the tensioning hole block and the sleeve, and the return spring is coaxially sleeved outside the reversing rod.

5. The robotic arm according to claim 1, wherein: The shapes of the tensioning hole block and the tensioning through hole are both elliptical.

6. The robotic arm according to claim 1, wherein: The plurality of tensioning ropes are all in contact with the two tensioning hole card blocks.

7. The robotic arm according to claim 1, wherein: Also included is a rope winding mechanism, the rope winding mechanism including a rope winding drum; Both ends of the tensioning rope are fixedly connected to the rope winding drum respectively.

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