Large-range-of motion two-degree-of-freedom wrist structure

Abstract

A large-range-of-motion two-degree-of-freedom wrist structure, comprising an arm bracket (1), wherein a wrist cross (2) is rotationally connected to the arm bracket (1), and a left pulley (3), a right pulley (4), an upper pulley (5) and a lower pulley (6) are respectively rotationally connected to the wrist cross (2). A first steel rope (31) wrapping around the left pulley and exiting from an upper side thereof and a second steel rope (32) wrapping around the left pulley and exiting from a lower side thereof are connected to the left pulley (3), and a third steel rope (41) wrapping around the right pulley and exiting from an upper side thereof and a fourth steel rope (42) wrapping around the right pulley and exiting from a lower side thereof are connected to the right pulley (4). The wrist structure further comprises a linkage steel rope (7) connected end to end, wherein the linkage steel rope (7) sequentially wraps around the upper pulley (5), the left pulley (3), the lower pulley (6) and the right pulley (4), the linkage steel rope (7) is fixed to the upper pulley (5), the left pulley (3) and the right pulley (4), respectively, and the upper pulley (5) is fixed to a palm structure.

Description

A wrist structure with large movable angle and two degrees of freedom Technical Field

[0001] The invention belongs to the technical field of bionic robots, and in particular relates to a wrist structure with large movable angle and two degrees of freedom. Background Art

[0002] With the continuous application of robotics technology, bionic manipulators have become a research hotspot in the field of robotics. In recent decades, in order to simulate the functions of the human hand, many research institutions at home and abroad have made fruitful research in the design, analysis, and control of bionic manipulators. The research of bionic manipulators is also considered one of the most challenging tasks.

[0003] The bionic wrist is a key component of a bionic manipulator. It not only gives the manipulator a more anthropomorphic appearance, but also enhances its flexibility and expands its maneuverability. Existing bionic wrists have been developed, but they are large, heavy, and have limited degrees of freedom.

[0004] Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the object of the present invention is to provide a wrist structure with a simple structure, a large movable angle and two degrees of freedom.

[0006] The technical solution adopted in the present invention is:

[0007] A wrist structure with a large movable angle and two degrees of freedom includes an arm support, which is rotatably connected to a wrist cross, and the wrist cross is rotatably connected to a left pulley, a right pulley, an upper pulley and a lower pulley, the left pulley is connected to a first steel rope wound from the upper side and a second steel rope wound from the lower side, and the right pulley is connected to a third steel rope wound from the upper side and a fourth steel rope wound from the lower side; and the structure also includes a linkage steel rope connected end to end, the linkage steel rope is sequentially wound around the upper pulley, the left pulley, the lower pulley and the right pulley, the linkage steel rope is respectively fixed to the upper pulley, the left pulley and the right pulley, and the upper pulley is fixed to the palm structure.

[0008] The wrist structure of the present invention primarily achieves upward, downward, left, and right wrist movements, as well as combined movements, through the coordination of four steel cables. When the steel cables on the same side of the left and right pulleys are pulled at the same speed, the left and right pulleys rotate in the same direction and at the same speed. Because the interlocking steel cables are fixed to the left and right pulleys, respectively, the interlocking steel cables drive the upper and lower pulleys to rotate in a vertical plane, and the upper pulley causes the palm structure to tilt up and down relative to the arm support. When the steel cables on opposite sides of the left and right pulleys are pulled at the same speed, the left and right pulleys rotate in opposite directions at the same speed. Because the interlocking steel cables are fixed to the left, right, and upper pulleys, respectively, the interlocking steel cables drive the upper pulley to rotate in a horizontal plane, and the upper pulley causes the palm structure to rotate left and right relative to the arm support. When the first, second, third, and fourth steel cables are in the remaining motion states, the entire wrist performs a combined motion of horizontal and vertical rotation.

[0009] The present invention realizes accurate control of the complex movements of the wrist structure only by operating the first steel rope, the second steel rope, the third steel rope and the fourth steel rope, and is flexible to operate; and there is no need to install complex structures such as a drive motor at the wrist. The structure is simple and the volume is small, and it is suitable for humanoid robots.

[0010] As a preferred embodiment of the present invention, the first and second steel ropes are each fixed to the left pulley at one end and wound around the circumference of the left pulley at the other end. The first and second steel ropes are wound around the left pulley over at least 1 / 4 of the circumference of the left pulley. The ends of the first and second steel ropes wound around the left pulley are parallel to the arm support. Since the first and second steel ropes are wound around the left pulley over at least 1 / 4 of the circumference of the left pulley, both the first and second steel ropes can pull the left pulley to rotate at least 90 degrees.

[0011] As a preferred embodiment of the present invention, the third and fourth steel ropes are each fixed to the right pulley at one end and wound around the circumference of the right pulley at the other end. The third and fourth steel ropes are wound around the right pulley over at least 1 / 4 of the circumference of the right pulley. The ends of the third and fourth steel ropes wound around the right pulley are parallel to the arm support. Since the third and fourth steel ropes are wound around the right pulley over at least 1 / 4 of the circumference of the right pulley, the third and fourth steel ropes can each pull the right pulley to rotate at least 90 degrees.

[0012] As a preferred embodiment of the present invention, when the first, second, third, and fourth cables are not pulled, the fixed connection point between the linkage cable and the upper pulley is located at the top of the upper pulley on the side facing away from the arm support. The linkage cable pulls the upper pulley through an equal range of rotation in both directions within the horizontal plane, at least 90°, ensuring a wide range of horizontal movement for the wrist structure.

[0013] As a preferred embodiment of the present invention, when the first steel rope, the second steel rope, the third steel rope and the fourth steel rope are not pulled, the fixed connection point between the linkage steel rope and the left pulley is located at the vertex of the left pulley facing the arm support side.

[0014] As a preferred embodiment of the present invention, when the first steel rope, the second steel rope, the third steel rope and the fourth steel rope are not pulled, the fixed connection point between the linkage steel rope and the right pulley is located at the vertex of the right pulley facing the arm support side.

[0015] As a preferred embodiment of the present invention, the axes of the upper and lower pulleys of the wrist cross are both located on the side of the left pulley's axis away from the arm support, and the axes of the upper and lower pulleys are both located on the side of the right pulley's axis away from the arm support. By staggering the upper and lower pulleys with the left and right pulleys, the length of the linkage rope can be lengthened, preventing interference between the linkage rope and the left or right pulleys when the linkage rope is pulled.

[0016] As a preferred embodiment of the present invention, the arm support includes an arm body, to which two support arms are fixed, and one end of a wrist cross connected to a left pulley and one end of a wrist cross connected to a right pulley are rotatably connected to the two support arms, respectively. There is sufficient space between the two support arms to accommodate the wrist cross.

[0017] As a preferred embodiment of the present invention, a weight-reducing notch is provided on the side of the upper pulley facing the arm support and on the side of the lower pulley facing the arm support. The linkage steel rope will not be wound around the side of the upper pulley or the lower pulley facing the arm support, so that the side can be weight-reduced.

[0018] As a preferred solution of the present invention, the wrist cross is a hollow structure to reduce weight.

[0019] The beneficial effects of the present invention are:

[0020] The present invention realizes accurate control of the complex movements of the wrist structure only by operating the first steel rope, the second steel rope, the third steel rope and the fourth steel rope, and is flexible to operate; and there is no need to install complex structures such as a drive motor at the wrist. The structure is simple and the volume is small, and it is suitable for humanoid robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic structural diagram of the present invention;

[0022] FIG2 is an exploded view of the present invention;

[0023] FIG3 is a schematic structural diagram of a first direction of a partial structure of the present invention;

[0024] FIG4 is a schematic structural diagram of a partial structure of the present invention in the second direction;

[0025] Figure 5 is a schematic structural diagram of the linkage steel rope.

[0026] In the figure: 1-arm support; 2-wrist cross; 3-left pulley; 4-right pulley; 5-upper pulley; 6-lower pulley; 7-linked steel rope; 11-arm body; 12-support arm; 31-first steel rope; 32-second steel rope; 41-third steel rope; 42-fourth steel rope. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features therein may be combined with each other unless there is a conflict.

[0029] As shown in Figures 1 to 5, the large-angle two-degree-of-freedom wrist structure of this embodiment includes an arm support 1, on which a wrist cross 2 is rotatably connected, and the wrist cross 2 is respectively rotatably connected to a left pulley 3, a right pulley 4, an upper pulley 5 and a lower pulley 6, the left pulley 3 is connected to a first steel rope 31 wound from the upper side and a second steel rope 32 wound from the lower side, and the right pulley 4 is connected to a third steel rope 41 wound from the upper side and a fourth steel rope 42 wound from the lower side; it also includes a linkage steel rope 7 connected end to end, the linkage steel rope 7 is sequentially wound around the upper pulley 5, the left pulley 3, the lower pulley 6 and the right pulley 4, the linkage steel rope 7 is fixed to the upper pulley 5, the left pulley 3 and the right pulley 4, respectively, and the upper pulley 5 is fixed to the palm structure.

[0030] The wrist structure of the present invention mainly realizes the up, down, left, right and composite movements of the wrist through the cooperation of four steel ropes. When the steel ropes on the same side of the left pulley 3 and the right pulley 4 are pulled at the same speed, the left pulley 3 and the right pulley 4 rotate in the same direction and at the same speed. Since the linkage steel rope 7 is fixed to the left pulley 3 and the right pulley 4 respectively, the linkage steel rope 7 drives the upper pulley 5 to rotate in the vertical plane, and the upper pulley 5 drives the palm structure to perform an up and down flipping movement relative to the arm support 1. When the steel ropes on the opposite sides of the left pulley 3 and the right pulley 4 are pulled at the same speed, the left pulley 3 and the right pulley 4 rotate in opposite directions and at the same speed. Since the linkage steel rope 7 is fixed to the left pulley 3, the right pulley 4 and the upper pulley 5 respectively, the linkage steel rope 7 drives the upper pulley 5 to rotate in the horizontal plane, and the upper pulley 5 drives the palm structure to perform a left and right rotation movement relative to the arm support 1. When the first steel rope 31, the second steel rope 32, the third steel rope 41 and the fourth steel rope 42 are in the other motion states, the entire wrist performs a compound motion of rotating in the horizontal plane and rotating in the vertical plane.

[0031] The present invention achieves accurate control of the complex movements of the wrist structure by operating only the first steel rope 31, the second steel rope 32, the third steel rope 41 and the fourth steel rope 42, and is flexible to operate; and there is no need to install complex structures such as a drive motor at the wrist. The structure is simple and the size is small, and it is suitable for humanoid robots.

[0032] The first and second steel ropes 31, 32 are each fixed to the left pulley 3 at one end and wound around the circumference of the left pulley 3 at the other end. The first and second steel ropes 31, 32 are wound around the left pulley 3 over at least 1 / 4 of the circumference of the left pulley 3. The ends of the first and second steel ropes 31, 32 wound around the left pulley 3 are parallel to the arm support 1. Since the first and second steel ropes 31, 32 are wound around the left pulley 3 over at least 1 / 4 of the circumference of the left pulley 3, both the first and second steel ropes 31, 32 can pull the left pulley 3 to rotate at least 90°.

[0033] The third and fourth steel ropes 41, 42 are each fixed to the right pulley 4 at one end and wound around the circumference of the right pulley 4 at the other end. The third and fourth steel ropes 41, 42 are wound around the right pulley 4 over at least 1 / 4 of the circumference of the right pulley 4. The ends of the third and fourth steel ropes 41, 42 wound around the right pulley 4 are parallel to the arm support 1. Since the third and fourth steel ropes 41, 42 are wound around the right pulley 4 over at least 1 / 4 of the circumference of the right pulley 4, both the third and fourth steel ropes 41, 42 can pull the right pulley 4 to rotate at least 90°.

[0034] Since the first steel rope 31 and the second steel rope 32 can both pull the left pulley 3 to rotate at least 90° and the third steel rope 41 and the fourth steel rope 42 can both pull the right pulley 4 to rotate at least 90°, when the left pulley 3 and the steel ropes on the same side of the left pulley 3 are pulled in the same direction and at the same speed, the upper pulley 5 can drive the palm structure to rotate at least 90° up or down, so that the wrist structure has a large angle of motion in the vertical plane.

[0035] When the first steel rope 31, the second steel rope 32, the third steel rope 41, and the fourth steel rope 42 are not pulled, the fixed connection point between the linkage steel rope 7 and the upper pulley 5 is located at the vertex of the upper pulley 5 on the side facing away from the arm support 1. The linkage steel rope 7 pulls the upper pulley 5 to rotate in the horizontal plane in the same range to both sides, and both are at least 90 degrees, ensuring that the wrist structure has a large range of motion in the horizontal plane.

[0036] When the first steel rope 31, the second steel rope 32, the third steel rope 41 and the fourth steel rope 42 are not pulled, the fixed connection point between the linkage steel rope 7 and the left pulley 3 is located at the vertex of the left pulley 3 facing the arm support 1. When the first steel rope 31, the second steel rope 32, the third steel rope 41 and the fourth steel rope 42 are not pulled, the fixed connection point between the linkage steel rope 7 and the right pulley 4 is located at the vertex of the right pulley 4 facing the arm support 1.

[0037] To prevent motion interference, the axes of the upper pulley 5 and the lower pulley 6 on the wrist cross 2 are both located on the side of the left pulley 3 away from the arm support 1, and the axes of the upper pulley 5 and the lower pulley 6 are both located on the side of the right pulley 4 away from the arm support 1. By staggering the upper pulley 5 and the lower pulley 6 with the left pulley 3 and the right pulley 4, the length of the linkage cable 7 can be lengthened, preventing interference between the linkage cable 7 and the left or right pulley 3 or 4 when the linkage cable 7 is pulled.

[0038] Specifically, the arm support 1 includes an arm body 11, on which two support arms 12 are fixed. One end of the wrist cross 2 connected to the left pulley 3 and one end of the wrist cross 2 connected to the right pulley 4 are respectively rotatably connected to the two support arms 12. There is sufficient space between the two support arms 12 to accommodate the wrist cross 2.

[0039] The upper pulley 5 and the lower pulley 6 facing the arm support 1 are both provided with weight-reducing notches. The linkage steel rope 7 is not wound around the upper pulley 5 or the lower pulley 6 facing the arm support 1, thus reducing weight on those sides. The wrist cross 2 is a hollow structure to reduce weight.

[0040] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, any technical solution that falls within the scope defined by the claims of the present invention falls within the scope of protection of the present invention.

Claims

1. A two-degree-of-freedom wrist structure with a large movement angle, characterized in that: It includes an arm bracket (1), a wrist cross (2) is rotatably connected to the arm bracket (1), a left pulley (3), a right pulley (4), an upper pulley (5) and a lower pulley (6) are respectively rotatably connected to the wrist cross (2), a first steel cable (31) wound out from the upper side and a second steel cable (32) wound out from the lower side are connected to the left pulley (3), a third steel cable (41) wound out from the upper side and a fourth steel cable (42) wound out from the lower side are connected to the right pulley (4); It also includes a linkage steel cable (7) connected end to end, the linkage steel cable (7) is successively wound around the upper pulley (5), the left pulley (3), the lower pulley (6) and the right pulley (4), the linkage steel cable (7) is fixed to the upper pulley (5), the left pulley (3) and the right pulley (4) respectively, and the upper pulley (5) is fixed to the palm structure.

2. The two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: Both the first steel cable (31) and the second steel cable (32) are fixed to the left pulley (3) at one end and wound out from the circumference of the left pulley (3) at the other end, and the winding range of the first steel cable (31) and the second steel cable (32) on the left pulley (3) is at least 1 / 4 of the circumference of the left pulley (3).

3. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: Both the third steel cable (41) and the fourth steel cable (42) are fixed to the right pulley (4) at one end and wound out from the circumference of the right pulley (4) at the other end, and the winding range of the third steel cable (41) and the fourth steel cable (42) on the right pulley (4) is at least 1 / 4 of the circumference of the right pulley (4).

4. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: When the first steel cable (31), the second steel cable (32), the third steel cable (41) and the fourth steel cable (42) are not pulled, the fixed connection point of the linkage steel cable (7) and the upper pulley (5) is located at the vertex on the side of the upper pulley (5) facing away from the arm bracket (1).

5. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: When the first steel cable (31), the second steel cable (32), the third steel cable (41) and the fourth steel cable (42) are not pulled, the fixed connection point of the linkage steel cable (7) and the left pulley (3) is located at the vertex on the side of the left pulley (3) facing the arm bracket (1).

6. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: When the first steel cable (31), the second steel cable (32), the third steel cable (41) and the fourth steel cable (42) are not pulled, the fixed connection point of the linkage steel cable (7) and the right pulley (4) is located at the vertex on the side of the right pulley (4) facing the arm bracket (1).

7. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: On the wrist cross (2), the axes of the upper pulley (5) and the lower pulley (6) are both located on the side of the axis of the left pulley (3) away from the arm bracket (1), and the axes of the upper pulley (5) and the lower pulley (6) are both located on the side of the axis of the right pulley (4) away from the arm bracket (1).

8. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: The arm bracket (1) includes an arm main body (11), two support arms (12) are fixed to the arm main body (11), and one end of the wrist cross (2) connecting the left pulley (3) and one end of the wrist cross (2) connecting the right pulley (4) are respectively rotatably connected to the two support arms (12).

9. A two-degree-of-freedom wrist structure with a large movement angle according to claim 1, characterized in that: Weight reduction notches are provided on both the side of the upper pulley (5) facing the arm bracket (1) and the side of the lower pulley (6) facing the arm bracket (1).

10. A two-degree-of-freedom wrist structure with a large movement angle according to any one of claims 1 to 9, characterized in that: The wrist cross (2) is of a hollow structure.

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