A two-rotation parallel type anthropomorphic wrist with a full low substructure compact

Abstract

The application discloses a two-rotation parallel type humanoid wrist with a full low substructure and compactness, relates to the technical field of parallel type humanoid joints, and comprises an arm support assembly, active branches, passive branches and a palm moving platform assembly. The arm support assembly is used for supporting the whole body. The active branches are provided in two, and the two active branches are arranged on the two sides of the arm support assembly. The passive branches are arranged at the end of the arm support assembly. The palm moving platform assembly is used for realizing the motion function of the humanoid wrist. One end of the arm support assembly is connected with the palm platform assembly through the active branches on the two sides. The other end of the arm support assembly is connected with the palm platform assembly through the passive branches. The application has the advantages of simple structure, convenient processing and maintenance, less wear, high precision and the like, and can realize the wrist flexion, wrist extension, wrist adduction and wrist abduction motion functions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of parallel type anthropomorphic joint, and particularly relates to a two-rotation parallel type anthropomorphic wrist with compact full lower pair structure. BACKGROUND

[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 future labor shortage problems. Anthropomorphic robots generally include a head, limbs and a torso, among which an anthropomorphic arm is generally a motion execution device for performing complex tasks. As a core component of the anthropomorphic arm, the wrist joint is the key to achieving flexible and accurate motion, and it is directly related to the ability of the anthropomorphic robot when performing tasks, and has become a research hotspot in the field of anthropomorphic joints in recent years.

[0003] By learning the biomechanical characteristics of the human wrist, the anthropomorphic wrist joint generally needs to achieve basic movements such as wrist flexion, wrist extension, wrist adduction, and wrist abduction, which are similar to the two-dimensional rotation that a U pair can achieve. Under the guidance of bionics principles, the academic community generally tends to use parallel mechanisms to simulate and achieve the complex motion of anthropomorphic wrist joints. Through the coordinated action of multiple branches, a parallel mechanism can accurately simulate the coordinated contraction and relaxation of wrist muscles. Therefore, many scholars have proposed parallel type anthropomorphic wrists that can achieve two rotations: such as Chinese patents CN201710388488.3 and CN201720156431.6. There are also parallel mechanisms that are not anthropomorphic wrists but can also achieve two rotations: such as Chinese patents CN202022125137.3 and CN201610989566.0. The above-mentioned patents all use a three-branch symmetric arrangement, which has a simple geometric structure while ensuring load capacity and flexibility, but they all use spherical hinge connections, which not only increase wear but also increase costs. At the same time, they generally use a three-branch double-platform structure, 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 point of the three branches and the platform, resulting in a relatively less compact overall structure. In addition, these designs often include spherical pairs in the kinematic pair, which are a type of high pair with line contact as the kinematic pair element. This can lead to increased friction and wear during motion, affected motion accuracy, and higher manufacturing and maintenance costs. SUMMARY

[0004] In view of the above, the present application overcomes the shortcomings of the prior art and proposes a parallel mechanism for an anthropomorphic wrist with two rotations, which has a simple and compact structure, high stiffness, a low pair motion, low cost, complete decoupling of motion, easy control and calibration, and precise control driven by a moving pair.

[0005] The technical scheme adopted is as follows: a two-rotation parallel type humanoid wrist with a compact low-substructure, comprising an arm support assembly, active branches, a passive branch and a palm moving platform assembly, the arm support assembly is used for supporting the whole, two active branches are arranged on the two sides of the arm support assembly, the passive branch is arranged at the end of the arm support assembly, the palm moving platform assembly is used for realizing the motion function of the humanoid wrist, one end of the arm support assembly is connected with the palm moving platform assembly through the active branches on the two sides, and the other end of the arm support assembly is connected with the palm moving platform assembly through the passive branch.

[0006] Further, the active branch comprises 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 moving platform assembly through the upper universal hinge, one end of the electric cylinder close to the lower universal hinge is provided with a U-shaped connecting groove one, two first connecting holes are formed in each U-shaped connecting groove one, the two first connecting holes are coaxial, the piston rod of the electric cylinder is provided with a U-shaped connecting groove two, two second connecting holes are formed in each U-shaped connecting groove two, and the two second connecting holes are coaxial.

[0007] Further, the passive branch comprises a passive branch universal hinge, the passive branch universal hinge is hinged with the arm support assembly through first connecting pins on the two sides, the passive branch universal hinge is hinged with the palm moving platform assembly through second connecting pins on the other two sides, the first connecting pins and the second connecting pins are vertically distributed, and the axes of the first connecting pins and the second connecting pins pass through the midpoint of the passive branch universal hinge.

[0008] Further, the arm support assembly comprises an arm support, flanges are fixedly installed with hinge shaft seats on the two sides of one end of the arm support, the electric cylinder is hinged with the hinge shaft seats through the lower universal hinge; two third connecting holes are formed in the other end of the arm support, the two third connecting holes are coaxial, the passive branch universal hinge is hinged with the third connecting holes on the arm support coaxially through first connecting pins on the two sides; one end of each hinge shaft seat away from the arm support is provided with a U-shaped connecting groove three in an inclined manner, two fourth connecting holes are formed in each U-shaped connecting groove three, the two fourth connecting holes in the same U-shaped connecting groove three are coaxial, and the axes thereof point to the center point of the passive branch universal hinge.

[0009] Further, the palm platform assembly comprises a palm platform, both sides of the palm platform are fixedly installed with a hinged seat one and a hinged seat two, the hinged seat one and the hinged seat two on the same side of the palm platform 6 are distributed at an angle of 45° on the palm platform, the piston rod of the electric cylinder is hinged with the hinged seat one through a upper end universal hinge, a U-shaped connecting groove four is formed in each hinged seat one, two fifth connecting holes are formed in each U-shaped connecting groove four, the two fifth connecting holes on the same U-shaped connecting groove four are coaxial, and the axis lines thereof point to the center point of the passive branch universal hinge, a sixth connecting hole is formed in each hinged seat two, the two sixth connecting holes are coaxial, and the axis line thereof points to the center point of the passive branch universal hinge, the passive branch universal hinge is hinged with the sixth connecting hole on the hinged seat two through another two side second connecting pins.

[0010] Further, the lower end universal hinge is hinged with the fourth connecting hole on the U-shaped connecting groove three through two side third connecting pins, the lower end universal hinge is hinged with the first connecting hole on the U-shaped connecting groove one through another two side fourth connecting pins, the third connecting pin and the fourth connecting pin are vertically distributed, and the axis lines of the third connecting pin and the fourth connecting pin pass the midpoint of the lower end universal hinge, the upper end universal hinge is hinged with the second connecting hole on the U-shaped connecting groove two through two side fifth connecting pins, the upper end universal hinge is hinged with the fifth connecting hole on the U-shaped connecting groove four through another two side sixth connecting pins, the fifth connecting pin and the sixth connecting pin are vertically distributed, and the axis lines of the fifth connecting pin and the sixth connecting pin pass the midpoint of the upper end universal hinge.

[0011] Further, the axis line of the third connecting pin on the lower end universal hinge points to the center point of the passive branch universal hinge, the axis line of the fourth connecting pin on the lower end universal hinge is parallel to the axis line of the fifth connecting pin on the upper end universal hinge, and the axis line 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 two-rotation parallel type humanoid wrist with a compact full low pair structure provided by the application has the advantages that (1) the two-rotation parallel type humanoid wrist comprises a symmetrical two-degree-of-freedom configuration with three branches, has high rigidity, large bearing capacity, a simple kinematic model and easy control; (2) all movements of the two-rotation parallel type humanoid wrist are composed of low pairs, the cost is low, the two-rotation parallel type humanoid wrist is driven by an electric cylinder, and precise control is easy to realize; and (3) the two-rotation parallel type humanoid wrist has the advantages of saving space, simple structure, convenient processing and maintenance, less wear and high precision. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1This is a schematic diagram of the overall structure of a compact, two-rotor parallel anthropomorphic wrist with a fully low-profile structure according to the present invention.

[0014] Figure 2 This is an exploded schematic diagram of a compact, two-rotor parallel anthropomorphic wrist structure with a fully low-profile structure according to the present invention.

[0015] Figure 3 This is a structural schematic diagram of a compact, two-rotor parallel anthropomorphic wrist and arm support assembly with a fully low-profile structure according to the present invention.

[0016] Figure 4 This is a structural schematic diagram of a compact, two-rotor parallel anthropomorphic wrist and palm motion platform assembly with a fully low-profile structure according to the present invention.

[0017] Figure 5 This is a schematic diagram of the maximum wrist flexion posture of a compact, two-rotor parallel anthropomorphic wrist with a fully low-profile structure according to the present invention.

[0018] Figure 6 This is a schematic diagram of the maximum wrist extension posture of a compact, two-rotor parallel anthropomorphic wrist with a fully low-profile structure according to the present invention.

[0019] Figure 7 This is a schematic diagram of the maximum wrist adduction posture of a compact, two-rotor parallel anthropomorphic wrist with a fully low-profile structure according to the present invention.

[0020] Figure 8 This is a schematic diagram of the maximum wrist abduction posture of a compact, two-rotor parallel anthropomorphic wrist with a fully low-profile structure according to the present invention.

[0021] Reference numerals: 1-Arm support; 2-Lower universal joint; 3-Electric cylinder; 4-Upper universal joint; 5-Passive branch universal joint; 6-Palm-driven platform; 7-Hinge shaft seat; 8-Hinge seat one; 9-Hinge seat two. Detailed Implementation

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

[0023] Example: Figures 1-8 As shown, the present invention provides a compact, two-rotor parallel anthropomorphic wrist with a low-profile structure, including an arm support assembly, active branches, passive branches, and a palm-moving platform assembly. The arm support assembly supports the entire structure. Two active branches are provided, one on each side of the arm support assembly. The passive branch is located at the end of the arm support assembly. The palm-moving platform assembly enables the movement function of the anthropomorphic wrist. One end of the arm support assembly is connected to the palm-moving platform assembly through the active branches on both sides; the other end of the arm support assembly is connected to the palm-moving platform assembly through the passive branch.

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

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

[0026] like Figure 3 As shown, the arm support assembly includes an arm support 1. Hinged shaft seats 7 are fixedly mounted on both sides of one end of the arm support 1 via flanges. The electric cylinder 3 is hinged to the hinged shaft seats 7 via a lower universal joint 2. Two third connecting holes are provided on the other end of the arm support 1, and the two third connecting holes are coaxial. The passive branch universal joint 5 is coaxially hinged to the third connecting holes on the arm support 1 via first connecting pins on both sides. Each hinged shaft seat 7 has an inclined U-shaped connecting groove 3 at the end away from the arm support 1. Two fourth connecting holes are provided on each U-shaped connecting groove 3, and the two fourth connecting holes on the same U-shaped connecting groove 3 are coaxial, with their axes pointing towards the center point of the passive branch universal joint 5.

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

[0028] The lower universal hinge 2 is coaxially hinged to the fourth connecting hole on the U-shaped connecting groove 3 via the third connecting pins on both sides. The lower universal hinge 2 is also coaxially hinged to the first connecting hole on the U-shaped connecting groove 1 via the fourth connecting pins on the other two sides. The third connecting pin and the fourth connecting pin are perpendicularly distributed, and the axes of the third connecting pin and the fourth connecting pin both pass through the midpoint of the lower universal hinge 2. The upper universal hinge 4 is coaxially hinged to the second connecting hole on the U-shaped connecting groove 2 via the fifth connecting pins on both sides. The upper universal hinge 4 is coaxially hinged to the fifth connecting hole on the U-shaped connecting groove 4 via the sixth connecting pins on the other two sides. The fifth connecting pin and the sixth connecting pin are perpendicularly distributed, and the axes of the fifth connecting pin and the sixth connecting pin both pass through the midpoint of the upper universal hinge 4.

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

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

[0031] like Figure 5 As shown, this invention presents a fully low-profile, compact, two-rotor parallel anthropomorphic wrist with a flexion limit posture. The wrist flexion movement is achieved by the piston rods of the two active branches of the electric cylinder 3 shortening the wrist together, with a total range of motion greater than 0° and less than or equal to 57°.

[0032] like Figure 6 As shown, the present invention provides a compact two-rotor parallel anthropomorphic wrist with a full low-profile structure, where the wrist extension movement is achieved by the piston rods of the two active branches of the electric cylinder 3 extending together, with a total range of motion greater than 0° and less than or equal to 69°.

[0033] like Figure 7 As shown, the present invention provides a compact two-rotor parallel anthropomorphic wrist with a full low-profile structure and a wrist adduction limit 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, with a total range of motion greater than 0° and less than or equal to 46°.

[0034] like Figure 8 As shown, the present invention provides a fully low-profile, compact, two-rotor parallel anthropomorphic wrist with a wrist abduction limit posture. 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, with a total range of motion greater than 0° and less than or equal to 46°.

Claims

1. A compact, two-rotor parallel anthropomorphic wrist with a fully low-pair structure, characterized in that, The device includes an arm support assembly, active branches, passive branches, and a hand-moving platform assembly. The arm support assembly provides overall support. Two active branches are located on either side of the arm support assembly. The passive branches are located at the ends of the arm support assembly. The hand-moving platform assembly enables anthropomorphic wrist movement. One end of the arm support assembly is connected to the hand-moving platform assembly via the two active branches, and the other end of the arm support assembly is connected to the hand-moving platform assembly via the passive branches. The active branch includes a lower universal joint (2), an electric cylinder (3), and an upper universal joint (4). The electric cylinder (3) is mounted on one side of the arm support assembly via the lower universal joint (2). The piston rod of the electric cylinder (3) is mounted on the palm-operated platform assembly via the upper universal joint (4). The end of the electric cylinder (3) near the lower universal joint (2) is provided with a U-shaped connecting groove 1. Each U-shaped connecting groove 1 has two first connecting holes, which are coaxial. The piston rod of the electric cylinder (3) is provided with a U-shaped connecting groove 2. Each U-shaped connecting groove 2 has two second connecting holes, which are coaxial. The passive branch includes a passive branch universal joint (5), which is hinged to the arm support assembly via first connecting pins on both sides. The passive branch universal joint (5) is hinged to the palm moving platform assembly via second connecting pins on the other two sides. The first connecting pin and the second connecting pin are perpendicularly distributed, and the axes of the first connecting pin and the second connecting pin both pass through the midpoint of the passive branch universal joint (5). The arm support assembly includes an arm support (1), and two hinged shaft seats (7) are fixedly installed on both sides of one end of the arm support (1) by flanges. The electric cylinder (3) is hinged to the hinged shaft seats (7) through the lower universal joint (2). Two third connecting holes are opened on the other end of the arm support (1). The two third connecting holes are coaxial. The passive branch universal joint (5) is coaxially hinged to the third connecting holes on the arm support (1) through the first connecting pins on both sides. Each hinged shaft seat (7) has a U-shaped connecting groove three inclinedly arranged on the end away from the arm support (1). Two fourth connecting holes are opened on each U-shaped connecting groove three. The two fourth connecting holes on the same U-shaped connecting groove three are coaxial, and the axis points to the center point of the passive branch universal joint (5). The palm-operated platform assembly includes a palm-operated platform (6). Hinges 1 (8) and 2 (9) are fixedly installed on both sides of the palm-operated platform (6). The hinges 1 (8) and 2 (9) on the same side of the palm-operated platform (6) are distributed at a 45° angle on the palm-operated platform (6). The piston rod of the electric cylinder (3) is hinged to the hinge 1 (8) via an upper universal joint (4). Each hinge 1 (8) is provided with a U-shaped connecting groove 4. Two fifth connecting holes are provided on each of the four connecting slots. The two fifth connecting holes on the same U-shaped connecting slot are coaxial, and their axes point to the center point of the passive branch universal joint (5). A sixth connecting hole is provided on each of the two hinge seats (9). The two sixth connecting holes are coaxial, and their axes point to the center point of the passive branch universal joint (5). The passive branch universal joint (5) is coaxially hinged to the sixth connecting hole on the hinge seat (9) through the second connecting pins on the other two sides.

2. The compact, two-rotor parallel anthropomorphic wrist with a fully low-pair structure as described in claim 1, characterized in that, The lower universal joint (2) is coaxially hinged to the fourth connecting hole on the U-shaped connecting groove three by the third connecting pins on both sides. The lower universal joint (2) is coaxially hinged to the first connecting hole on the U-shaped connecting groove one by the fourth connecting pins on the other two sides. The third connecting pin and the fourth connecting pin are perpendicularly distributed, and the axes of the third connecting pin and the fourth connecting pin both pass through the midpoint of the lower universal joint (2). The upper universal joint (4) is coaxially hinged to the second connecting hole on the U-shaped connecting groove two by the fifth connecting pins on both sides. The upper universal joint (4) is coaxially hinged to the fifth connecting hole on the U-shaped connecting groove four by the sixth connecting pins on the other two sides. The fifth connecting pin and the sixth connecting pin are perpendicularly distributed, and the axes of the fifth connecting pin and the sixth connecting pin both pass through the midpoint of the upper universal joint (4).

3. The compact, two-rotor parallel anthropomorphic wrist with a fully low-pair structure as described in claim 2, characterized in that, The axis of the third connecting pin on the lower universal joint (2) points to the center point of the passive branch universal joint (5), and the axis of the fourth connecting pin on the lower universal joint (2) is parallel to the axis of the fifth connecting pin on the upper universal joint (4); the axis of the sixth connecting pin on the upper universal joint (4) points to the center point of the passive branch universal joint (5).

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