Two-rotation parallel connection type anthropomorphic wrist with full low pair and compact structure

Abstract

The invention discloses a full-low-pair compact-structure two-rotation parallel-connection type anthropomorphic wrist, and relates to the technical field of parallel-connection type anthropomorphic joints, the full-low-pair compact-structure two-rotation parallel-connection type anthropomorphic wrist comprises an arm support assembly, two active branches, two passive branches and a palm moving platform assembly, the two driving branches are arranged on the two sides of the arm support assembly respectively, the driven branches are arranged at the end of the arm support assembly, the palm moving platform assembly is used for achieving the motion function of simulating the human wrist, and one end of the arm support assembly is connected with the palm moving platform assembly through the driving branches on the two sides; the other end of the arm support assembly is connected with the palm platform assembly through a passive branch. The mechanical arm has the advantages of being simple in structure, convenient to machine and maintain, small in abrasion, high in precision and the like, and the functions of wrist bending, wrist stretching, wrist adduction and wrist abduction movement of the wrist can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of parallel anthropomorphic joints, and in particular to a two-turn parallel anthropomorphic wrist with a compact full-low pair structure. Background Art

[0002] Anthropomorphic robots have stronger tolerance and adaptability than humans, and can replace humans to perform complex tasks in unstructured environments, becoming an effective means to solve the problem of future labor shortages. Anthropomorphic robots generally consist of three parts: head, limbs and torso. The anthropomorphic arm is generally a motion execution device for performing complex tasks. As the core component of the anthropomorphic arm, the wrist joint is the key to achieving flexible and precise movement. It is directly related to the ability of the anthropomorphic robot to perform tasks, and has become a research hotspot in the field of anthropomorphic joints in recent years.

[0003] Drawing on the biomechanical properties of the human wrist, the anthropomorphic wrist joint generally needs to realize basic movements such as wrist flexion, wrist extension, wrist adduction, and wrist abduction, which is similar to the two-dimensional rotation that can be achieved by the U-joint. Under the guidance of the principles of bionics, the academic community generally tends to use parallel mechanisms to simulate and realize the complex movements of the anthropomorphic wrist joint. The parallel mechanism can accurately simulate the coordinated contraction and relaxation of wrist muscles through the synergistic action of its multiple branches. Therefore, many scholars have proposed a parallel anthropomorphic wrist that can achieve two rotations: such as Chinese patents CN201710388488.3, ​​CN201720156431.6. There are also parallel mechanisms that are not anthropomorphic wrists, but can also achieve two rotations: such as Chinese patents CN202022125137.3, CN201610989566.0 The above patents all adopt a three-branch symmetrical arrangement, which has a simple geometric structure while ensuring load-bearing capacity and flexibility. However, ball joints are used in the structure, which not only increases wear but also increases costs. At the same time, a three-branch double-platform structure is generally adopted, and the branches are symmetrically arranged between the upper and lower platforms. Although this design can achieve the required motion function, the minimum size of the anthropomorphic wrist joint in the radial direction is limited by the diameter of the circumscribed circle of the connection points between the three branches and the platforms, resulting in a relatively compact overall structure. In addition, these designs usually include spherical pairs in the kinematic pairs. As a type of high pair, the kinematic pair elements of the spherical pair are line contacts, which may lead to increased friction and wear during movement, affected movement accuracy, and higher manufacturing and maintenance costs. Summary of the invention

[0004] In view of the above situation, the present invention overcomes the shortcomings of the prior art and proposes an anthropomorphic wrist two-turn parallel mechanism with simple and compact structure, high rigidity, low motion pair structure, low cost, complete motion decoupling, easy control and calibration, and driven by a moving pair to achieve precise control.

[0005] The adopted technical solution is: a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure, including an arm support assembly, an active branch, a passive branch and a palm motion platform assembly. The arm support assembly is used to support the whole, and there are two active branches, which are respectively arranged on both sides of the arm support assembly, and the passive branch is arranged at the end of the arm support assembly. The palm motion platform assembly is used to realize the movement function of the anthropomorphic wrist, and one end of the arm support assembly is connected to the palm platform assembly through the active branches on both sides; the other end of the arm support assembly is connected to the palm platform assembly through the passive branch.

[0006] Furthermore, the active branch includes a lower universal hinge, an electric cylinder and an upper universal hinge, the electric cylinder is installed on one side of the arm support assembly through the lower universal hinge, the piston rod of the electric cylinder is installed on the palm platform assembly through the upper universal hinge, and a U-shaped connecting groove 1 is provided at one end of the electric cylinder close to the lower universal hinge, each of the U-shaped connecting grooves 1 is provided with two first connecting holes, and the two first connecting holes are coaxial, and a U-shaped connecting groove 2 is provided on the piston rod of the electric cylinder, each of the U-shaped connecting grooves 2 is provided with two second connecting holes, and the two second connecting holes are coaxial.

[0007] Furthermore, the passive branch includes a passive branch universal hinge, which is hinged to the arm support assembly through first connecting pins on both sides, and is hinged to the palm platform assembly through second connecting pins on the other two sides, the first connecting pin and the second connecting pin are vertically distributed, and the axes of the first connecting pin and the second connecting pin both pass through the midpoint of the passive branch universal hinge.

[0008] Furthermore, the arm support assembly includes an arm support, and both sides of one end of the arm support are fixedly installed with articulated shaft seats through flanges, and the electric cylinder is hinged to the articulated shaft seat through a universal hinge at the lower end; two third connecting holes are opened on the other end of the arm support, and the two third connecting holes are coaxial, and the passive branch universal hinge is coaxially hinged with the third connecting holes on the arm support through the first connecting pins on both sides; each of the articulated shaft seats is obliquely provided with a U-shaped connecting groove three at one end away from the arm support, and each of the U-shaped connecting grooves three is provided with two fourth connecting holes, and the two fourth connecting holes on the same U-shaped connecting groove three are coaxial, and the axes all point to the center point of the passive branch universal hinge.

[0009] Furthermore, the palm moving platform assembly includes a palm moving platform, and an articulated seat 1 and an articulated seat 2 are fixedly installed on both sides of the palm moving platform, and the articulated seat 1 and the articulated seat 2 on the same side of the palm platform 6 are distributed at a 45° angle on the palm moving platform, and the piston rod of the electric cylinder is hinged to the articulated seat 1 through an upper end universal hinge; each of the articulated seat 1 is provided with a U-shaped connecting groove 4, and each of the U-shaped connecting groove 4 is provided with two fifth connecting holes, and the two fifth connecting holes on the same U-shaped connecting groove 4 are coaxial, and the axes point to the center point of the passive branch universal hinge; each of the articulated seat 2 is provided with a sixth connecting hole, and the two sixth connecting holes are coaxial, and the axes point to the center point of the passive branch universal hinge, and the passive branch universal hinge is coaxially hinged to the sixth connecting hole on the articulated seat 2 through the second connecting pins on the other two sides.

[0010] Furthermore, the lower end universal hinge is coaxially hinged to the fourth connecting hole on the U-shaped connecting groove three through the third connecting pins on both sides, and the lower end universal hinge is coaxially hinged to the first connecting hole on the U-shaped connecting groove one through the fourth connecting pins on the other two sides, the third connecting pin and the fourth connecting pin are vertically distributed, and the axes of the third connecting pin and the fourth connecting pin pass through the midpoint of the lower end universal hinge; the upper end universal hinge is coaxially hinged to the second connecting hole on the U-shaped connecting groove two through the fifth connecting pins on both sides, and the upper end universal hinge is coaxially hinged to the fifth connecting hole on the U-shaped connecting groove four through the sixth connecting pins on the other two sides, the fifth connecting pin and the sixth connecting pin are vertically distributed, and the axes of the fifth connecting pin and the sixth connecting pin pass through the midpoint of the upper end universal hinge.

[0011] Furthermore, the axis of the third connecting pin on the lower end universal hinge points to the center point of the passive branch universal hinge, the axis of the fourth connecting pin on the lower end universal hinge is parallel to the axis of the fifth connecting pin on the upper end universal hinge; the axis of the sixth connecting pin on the upper end universal hinge points to the center point of the passive branch universal hinge.

[0012] Compared with the prior art, the present invention has the following advantages: (1) The present invention provides a two-turn parallel anthropomorphic wrist with a compact full low-pair structure, which comprises a symmetrical two-degree-of-freedom configuration with three branches, high rigidity, large load-bearing capacity, simple kinematic model, and easy control; (2) The present invention provides a two-turn parallel anthropomorphic wrist with a compact full low-pair structure, in which all movements are composed of low-pair components at a low cost and are driven by electric cylinders, which facilitates precise control; (3) The present invention provides a two-turn parallel anthropomorphic wrist with a compact full low-pair structure, which has the advantages of saving space, simple structure, easy processing and maintenance, less wear, and high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a schematic diagram of the overall structure of a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure according to the present invention.

[0014] Figure 2 It is an exploded schematic diagram of a two-turn parallel anthropomorphic wrist structure with a full low-pair structure and compact structure according to the present invention.

[0015] Figure 3 It is a structural schematic diagram of a two-turn parallel type anthropomorphic wrist and arm support assembly with a fully low-pair structure and compact structure according to the present invention.

[0016] Figure 4 The present invention is a structural schematic diagram of a two-turn parallel type anthropomorphic wrist and palm motion platform assembly with a fully low-pair structure and compact structure.

[0017] Figure 5 It is a schematic diagram of the maximum wrist flexion posture of a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure according to the present invention.

[0018] Figure 6 The present invention is a schematic diagram of a maximum wrist extension posture of a two-turn parallel anthropomorphic wrist with a full low-pair compact structure.

[0019] Figure 7 It is a schematic diagram of a maximum wrist adduction posture of a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure according to the present invention.

[0020] Figure 8 The present invention is a schematic diagram of a maximum wrist abduction posture of a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure.

[0021] Figure numbers: 1-arm bracket; 2-lower end universal hinge; 3-electric cylinder; 4-upper end universal hinge; 5-passive branch universal hinge; 6-palm moving platform; 7-articulated shaft seat; 8-articulated seat one; 9-articulated seat two. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0023] Example: Figure 1-Figure 8 As shown, the present invention provides a two-turn parallel anthropomorphic wrist with a full low-pair structure and compact structure, including an arm support assembly, an active branch, a passive branch and a palm motion platform assembly. The arm support assembly is used to support the whole, two active branches are provided, and the two active branches are respectively provided on both sides of the arm support assembly, and the passive branch is provided at the end of the arm support assembly. The palm motion platform assembly is used to realize the movement function of the anthropomorphic wrist, and one end of the arm support assembly is connected to the palm platform assembly through the active branches on both sides; the other end of the arm support assembly is connected to the palm platform assembly through the passive branch.

[0024] The active branch includes a lower universal hinge 2, an electric cylinder 3 and an upper universal hinge 4. The electric cylinder 3 is installed on one side of the arm support assembly through the lower universal hinge 2. The piston rod of the electric cylinder 3 is installed on the palm platform assembly through the upper universal hinge 4. A U-shaped connecting groove 1 is provided at one end of the electric cylinder 3 close to the lower universal hinge 2. Each U-shaped connecting groove 1 has two first connecting holes, and the two first connecting holes are coaxial. A U-shaped connecting groove 2 is provided on the piston rod of the electric cylinder 3. Each U-shaped connecting groove 2 has two second connecting holes, and the two second connecting holes are coaxial.

[0025] The passive branch includes a passive branch universal hinge 5, which is hinged to the arm support assembly through first connecting pins on both sides, and is hinged to the palm platform assembly through second connecting pins on the other two sides. The first connecting pin and the second connecting pin are vertically distributed, and the axes of the first connecting pin and the second connecting pin pass through the midpoint of the passive branch universal hinge 5.

[0026] like Figure 3 As shown, the arm bracket assembly includes an arm bracket 1, and both sides of one end of the arm bracket 1 are fixedly installed with articulated shaft seats 7 through flanges, and the electric cylinder 3 is hinged to the articulated shaft seat 7 through the universal hinge 2 at the lower end; two third connecting holes are opened on the other end of the arm bracket 1, and the two third connecting holes are coaxial, and the passive branch universal hinge 5 is coaxially hinged with the third connecting holes on the arm bracket 1 through the first connecting pins on both sides; each articulated shaft seat 7 is obliquely provided with a U-shaped connecting groove three at one end away from the arm bracket 1, and each U-shaped connecting groove three is provided with two fourth connecting holes, and the two fourth connecting holes on the same U-shaped connecting groove three are coaxial, and the axes all point to the center point of the passive branch universal hinge 5.

[0027] like Figure 4 As shown, the palm movable platform assembly includes a palm movable platform 6, and an articulated seat 1 8 and an articulated seat 2 9 are fixedly installed on both sides of the palm movable platform 6. The articulated seat 1 8 and the articulated seat 2 9 on the same side of the palm platform 6 are distributed at a 45° angle on the palm movable platform 6, and the piston rod of the electric cylinder 3 is hinged to the articulated seat 1 8 through the upper end universal hinge 4; each articulated seat 1 8 is provided with a U-shaped connecting groove four, and each U-shaped connecting groove four is provided with two fifth connecting holes, and the two fifth connecting holes on the same U-shaped connecting groove four are coaxial, and the axes point to the center point of the passive branch universal hinge 5; each articulated seat 2 9 is provided with a sixth connecting hole, and the two sixth connecting holes are coaxial, and the axes point to the center point of the passive branch universal hinge 5, and the passive branch universal hinge 5 is coaxially hinged to the sixth connecting hole on the articulated seat 2 9 through the second connecting pins on the other two sides.

[0028] The lower end universal hinge 2 is coaxially hinged to the fourth connecting hole on the U-shaped connecting groove three through the third connecting pins on both sides, and the lower end universal hinge 2 is coaxially hinged to the first connecting hole on the U-shaped connecting groove one through the fourth connecting pins on the other two sides, the third connecting pin and the fourth connecting pin are vertically distributed, and the axes of the third connecting pin and the fourth connecting pin pass through the midpoint of the lower end universal hinge 2; the upper end universal hinge 4 is coaxially hinged to the second connecting hole on the U-shaped connecting groove two through the fifth connecting pins on both sides, and the upper end universal hinge 4 is coaxially hinged to the fifth connecting hole on the U-shaped connecting groove four through the sixth connecting pins on the other two sides, the fifth connecting pin and the sixth connecting pin are vertically distributed, and the axes of the fifth connecting pin and the sixth connecting pin pass through the midpoint of the upper end universal hinge 4.

[0029] The axis of the third connecting pin on the lower end universal hinge 2 points to the center point of the passive branch universal hinge 5, the axis of the fourth connecting pin on the lower end universal hinge 2 is parallel to the axis of the fifth connecting pin on the upper end universal hinge 4; the axis of the sixth connecting pin on the upper end universal hinge 4 points to the center point of the passive branch universal hinge 5.

[0030] The working principle of the present invention is: The wrist flexion and extension movements of the present invention are achieved by simultaneously shortening or extending the piston rods of the electric cylinders 3 in the two active branches; the wrist adduction and abduction movements of the present invention are achieved by respectively moving the piston rods of the electric cylinders 3 in the two active branches to different lengths.

[0031] like Figure 5 As shown, the wrist flexion extreme posture of a two-turn parallel anthropomorphic wrist with a full low-pair compact structure of the present invention, the wrist flexion movement is achieved by shortening the piston rods of the electric cylinders 3 in the two active branches together, and the total movement range is greater than 0° and less than or equal to 57°.

[0032] like Figure 6 As shown, the present invention provides a two-turn parallel anthropomorphic wrist with a fully low-pair structure and compact wrist extension extreme posture. The wrist extension movement is achieved by the joint extension of the piston rods of the electric cylinders 3 in the two active branches, and the total movement range is greater than 0° and less than or equal to 69°.

[0033] like Figure 7 As shown, the present invention is a two-turn parallel type anthropomorphic wrist with a full low-pair structure and compact wrist adduction extreme posture. The wrist adduction movement is achieved by shortening the piston rod of the electric cylinder 3 in the first active branch and extending the piston rod of the electric cylinder 3 in the second active branch. The total movement range is greater than 0° and less than or equal to 46°.

[0034] like Figure 8 As shown, the present invention is a two-turn parallel type anthropomorphic wrist with a fully low-pair structure and compact wrist abduction extreme posture, and the wrist adduction movement is achieved by extending the piston rod of the electric cylinder 3 in the second active branch and shortening the piston rod of the electric cylinder 3 in the first active branch, and the total movement range is greater than 0° and less than or equal to 46°.

Claims

1. A two-turn parallel anthropomorphic wrist with a compact full-low pair structure, characterized in that: It includes an arm support assembly, an active branch, a passive branch and a palm motion platform assembly. The arm support assembly is used to support the whole. Two active branches are provided, and the two active branches are respectively provided on both sides of the arm support assembly. The passive branch is provided at the end of the arm support assembly. The palm motion platform assembly is used to realize the movement function of the anthropomorphic wrist. One end of the arm support assembly is connected to the palm platform assembly through the active branches on both sides; the other end of the arm support assembly is connected to the palm platform assembly through the passive branch.

2. A two-turn parallel type anthropomorphic wrist with a full low-profile structure and compact structure as claimed in claim 1, characterized in that: The active branch comprises a lower universal hinge (2), an electric cylinder (3) and an upper universal hinge (4); the electric cylinder (3) is mounted on one side of the arm support assembly via the lower universal hinge (2); the piston rod of the electric cylinder (3) is mounted on the palm platform assembly via the upper universal hinge (4); a U-shaped connecting groove 1 is provided at one end of the electric cylinder (3) close to the lower universal hinge (2); each of the U-shaped connecting grooves 1 is provided with two first connecting holes, and the two first connecting holes are coaxial; a U-shaped connecting groove 2 is provided on the piston rod of the electric cylinder (3); each of the U-shaped connecting grooves 2 is provided with two second connecting holes, and the two second connecting holes are coaxial.

3. A two-turn parallel type anthropomorphic wrist with a full low-profile structure and compact structure as claimed in claim 2, characterized in that: The passive branch comprises a passive branch universal hinge (5), the passive branch universal hinge (5) being hinged to the arm support assembly via first connecting pins on two sides, the passive branch universal hinge (5) being hinged to the palm platform assembly via second connecting pins on the other two sides, the first connecting pin and the second connecting pin being vertically distributed, and the axes of the first connecting pin and the second connecting pin both passing through the midpoint of the passive branch universal hinge (5).

4. A two-turn parallel type anthropomorphic wrist with a full low-profile structure and compact structure as claimed in claim 3, characterized in that: The arm support assembly comprises an arm support (1), and both sides of one end of the arm support (1) are fixedly mounted with an articulated shaft seat (7) via flanges, and the electric cylinder (3) is hinged to the articulated shaft seat (7) via a universal hinge (2) at the lower end; two third connection holes are provided on the other end of the arm support (1), and the two third connection holes are coaxial, and the passive branch universal hinge (5) is coaxially articulated with the third connection holes on the arm support (1) via first connection pins on both sides; each of the articulated shaft seats (7) is obliquely provided with a U-shaped connection groove three at one end away from the arm support (1), and each of the U-shaped connection grooves three is provided with two fourth connection holes, and the two fourth connection holes on the same U-shaped connection groove three are coaxial, and the axes both point to the center point of the passive branch universal hinge (5).

5. A two-turn parallel type anthropomorphic wrist with full low-profile structure and compact structure as claimed in claim 4, characterized in that: The palm-moving platform assembly comprises a palm-moving platform (6), and both sides of the palm-moving platform (6) are fixedly mounted with an articulated seat 1 (8) and an articulated seat 2 (9), and the articulated seat 1 (8) and the articulated seat 2 (9) on the same side of the palm platform 6 are distributed at an angle of 45° on the palm-moving platform (6), and the piston rod of the electric cylinder (3) is hinged to the articulated seat 1 (8) through an upper universal hinge (4); each of the articulated seats 1 (8) is provided with a U-shaped connecting groove 4, and each of the U-shaped connecting grooves 1 and 1 are connected to the articulated seat 1 (8). Two fifth connection holes are provided on each groove four, the two fifth connection holes on the same U-shaped connection groove four are coaxial, and the axes point to the center point of the passive branch universal hinge (5); a sixth connection hole is provided on each hinge seat two (9), the two sixth connection holes are coaxial, and the axes point to the center point of the passive branch universal hinge (5), and the passive branch universal hinge (5) is coaxially hinged to the sixth connection hole on the hinge seat two (9) through the second connection pins on the other two sides.

6. A two-turn parallel type anthropomorphic wrist with a full low-profile structure and compact structure as claimed in claim 5, characterized in that: The lower end universal hinge (2) is coaxially hinged to the fourth connection hole on the U-shaped connection groove three through the third connection pins on both sides, and the lower end universal hinge (2) is coaxially hinged to the first connection hole on the U-shaped connection groove one through the fourth connection pins on the other two sides, the third connection pin and the fourth connection pin are vertically distributed, and the axes of the third connection pin and the fourth connection pin pass through the midpoint of the lower end universal hinge (2); the upper end universal hinge (4) is coaxially hinged to the second connection hole on the U-shaped connection groove two through the fifth connection pins on both sides, and the upper end universal hinge (4) is coaxially hinged to the fifth connection hole on the U-shaped connection groove four through the sixth connection pins on the other two sides, the fifth connection pin and the sixth connection pin are vertically distributed, and the axes of the fifth connection pin and the sixth connection pin pass through the midpoint of the upper end universal hinge (4).

7. A two-turn parallel type anthropomorphic wrist with a full low-profile structure and compact structure as claimed in claim 6, characterized in that: The axis of the third connecting pin on the lower end universal hinge (2) points to the center point of the passive branch universal hinge (5); the axis of the fourth connecting pin on the lower end universal hinge (2) is parallel to the axis of the fifth connecting pin on the upper end universal hinge (4); and the axis of the sixth connecting pin on the upper end universal hinge (4) points to the center point of the passive branch universal hinge (5).

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