CN113858257B - Robot wrist with large-range variable rigidity - Google Patents

Abstract

The invention discloses a robot wrist with large-range variable rigidity, which comprises a variable rigidity driver and a wrist assembly, wherein a rotating shaft is arranged on the variable rigidity driver, an elastic element is arranged on the rotating shaft, mounting rods are arranged on two sides of the elastic element and fixedly arranged on the variable rigidity driver, the wrist assembly comprises a top rod, a pulley frame, a bottom rod, a mounting rod and a connecting rod, a planar parallel mechanism is arranged on the top rod, the planar parallel mechanism comprises an upper platform, a lower platform and two groups of branched chain structures, a plurality of groups of limiting columns are arranged on the branched chain structures, the bottom rod and the connecting rod, a wire column is arranged on the upper platform, a traction wire is arranged on the wire column, one end of the traction wire is fixed on the wire column, and the other end of the traction wire is connected with the elastic element through the limiting columns and the pulleys.

Description

A robot wrist with variable stiffness in a wide range

technical field

The invention relates to the technical field of robots, in particular to a robot wrist with variable stiffness in a large range.

Background technique

In the process of moving the industrial robot to the work object, the stiffness of the wrist is required to reduce the deformation and oscillation of the wrist. At the same time, the deformation of the variable stiffness wrist due to low stiffness is avoided, thereby increasing the positioning accuracy of the variable stiffness wrist to accurately locate the position of the work object. After that, in the process of contacting with the work object, due to the pose error between the robot and the work object, there is jamming between the robot and the work object. It is required that the stiffness of the variable-stiffness wrist is small, and under the action of the jamming resistance, the relative pose between the robot and the work object can be automatically adjusted to compensate the pose error to complete the work. Therefore, according to different processes in the robot's operation process, the wrist needs to be adjusted to different stiffnesses in a large range in real time online.

Contents of the invention

The purpose of the present invention is to solve the technical problems existing in the prior art, and to provide a robot wrist with variable stiffness in a wide range.

In order to achieve the above object, the technical solution provided by the present invention is: a robot wrist with variable stiffness in a large range, including a variable stiffness driver and a wrist assembly, the variable stiffness driver is provided with a rotating shaft, and the rotating shaft is provided with an elastic element, Both sides of the elastic element are provided with installation rods, and the installation rods are fixedly arranged on the variable stiffness driver. The wrist assembly includes a top rod, a pulley frame, a bottom rod and a connecting rod, and the bottom rod is arranged on the Between the variable stiffness driver and the installation rod, the bottom rod is provided with a shaft hole through which the rotating shaft passes, the bottom rod is fixedly connected to the connecting rod, and the connecting rod is hinged to the pulley frame, The pulley frame is provided with a pulley, the pulley frame is fixedly connected to the top bar, and the top bar is provided with a plane parallel mechanism, and the plane parallel mechanism includes an upper platform, a lower platform and two sets of branch chain structures, The upper platform and the lower platform are connected by the branch chain structure, and the branch chain structure, the bottom rod and the connecting rod are all provided with multiple sets of limit columns, and there is a gap between the limit columns. A wire column is arranged on the platform, and a traction line is arranged on the line column, one end of the traction line is fixed on the line column, and the other end of the traction line passes through the limit column and the pulley respectively to connect with the elastic element.

Preferably, a limit assembly is also provided between the upper platform and the lower platform, and the limit assembly includes an upper limit block and a lower limit block, and the upper limit block and the lower limit block are respectively connected to the upper platform and the lower platform. hinged.

Preferably, the branch chain structure includes an upper adapter plate and a lower adapter plate, the upper adapter plate is hinged with the upper platform and the lower adapter plate at the same time, and the lower adapter plate is hinged with the lower adapter plate Platform hinged.

Preferably, an actuator is arranged on the upper platform.

Beneficial effects of the present invention:

The invention can install a wrist with variable stiffness in a wide range on an industrial robot, and the wrist can be adjusted to different stiffnesses in a wide range online in real time according to different procedures in the robot's operation process. When the industrial robot moves to the work object, the wrist stiffness is adjusted to a larger value to avoid deformation and oscillation during the robot movement, and to increase the accuracy of the robot's positioning to the work object; in the process of contact with the work object, due to the There is a pose error, and there is a jam between the robot and the work object. At this time, the wrist stiffness is adjusted to a smaller value to become a compliant wrist. Under the action of the jamming resistance, the relative pose between the robot and the work object is automatically adjusted to compensate for pose errors to complete the job.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention.

Fig. 1 is the partial structure schematic diagram of the variable stiffness wrist of embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the overall structure of a variable stiffness wrist according to Embodiment 2 of the present invention;

Fig. 3 is a schematic diagram of the mechanism of the wrist with variable stiffness in Embodiment 3 of the present invention;

Fig. 4 is the overall structural diagram of the industrial robot equipped with the present invention.

Notes on drawings:

1-bottom rod 2-connecting rod 3-pulley frame 4-traction line 5-top rod 6-limit column 7-lower adapter plate 8-lower platform 9-upper adapter plate 10-upper platform 11-hinge shaft 12 - Lower limit block 13 - Upper limit block 14 - Wire column 15 - Elastic element 16 - Rotating shaft 17 - Mounting rod 18 - Variable stiffness driver 19 - Actuator 20 - Planar parallel structure 21 - Wrist assembly.

Detailed ways

This part will describe the specific embodiment of the present invention in detail, and the preferred embodiment of the present invention is shown in the accompanying drawings. Each technical feature and overall technical solution of the invention, but it should not be understood as a limitation on the protection scope of the present invention.

In the description of the present invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc. indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only In order to facilitate the description of the present invention and simplify the description, it does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

In the description of the present invention, several means one or more, and multiple means more than two. Greater than, less than, exceeding, etc. are understood as not including the original number, and above, below, within, etc. are understood as including the original number. If the description of the first and second is only for the purpose of distinguishing the technical features, it cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features relation.

In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

With reference to Fig. 1-4, preferred embodiment of the present invention, a kind of robot wrist of variable stiffness in a large range, comprises variable stiffness wrist body, and described variable stiffness wrist body includes variable stiffness driver 18 and wrist assembly 21, and described variable stiffness driver 18 is provided with a rotating shaft 16, the rotating shaft 16 is provided with an elastic element 15, and the two sides of the elastic element 15 are provided with mounting rods 17, and the mounting rods 17 are fixedly arranged on the variable stiffness driver 18, and the wrist The assembly 21 includes a top rod 5, a pulley frame 3, a bottom rod 1 and a connecting rod 2, the bottom rod 1 is arranged between the variable stiffness driver 18 and the installation rod 17, and the bottom rod 1 is provided with The shaft hole through which the rotating shaft 16 passes, the bottom rod 1 is fixedly connected with the connecting rod 2, the connecting rod 2 is hinged with the pulley frame 3, the pulley frame 3 is provided with a pulley, and the pulley frame 3 is fixedly connected with the top bar 5, and the top bar 5 is provided with a planar parallel mechanism 20, and the planar parallel mechanism 20 includes an upper platform 10, a lower platform 8 and two sets of branch chain structures, and the upper platform 10 and The lower platform 8 is connected by the branch chain structure, and the branch chain structure, the bottom rod 1 and the connecting rod 2 are all provided with multiple sets of limit columns 6, and a gap is provided between the limit columns 6, and the upper The platform 10 is provided with a line column 14, and the line column 14 is provided with a pull wire 4, one end of the pull line 4 is fixed on the line column 14, and the other end of the pull line 4 passes through the limit column 6 and the The pulley is connected with the elastic element 15 .

As a preferred embodiment of the present invention, it also has the following additional technical features:

In this embodiment, a limit assembly is also provided between the upper platform 10 and the lower platform 8, and the limit assembly includes an upper limit block 13 and a lower limit block 12, and the upper limit block 13 and the lower limit block 12 are respectively Hinged with the upper platform 10 and the lower platform 8, the lower limit block 12 can rotate around the hinge shaft 11 at the hinge of the lower platform 8, and the upper limit block 13 can rotate around the hinge shaft 11 at the hinge of the lower limit block 12. The platform 10 can rotate around the hinge shaft 11 where the upper limit block 13 is hinged.

In this embodiment, the branch chain structure includes an upper adapter plate 9 and a lower adapter plate 7, the upper adapter plate 9 is hinged to the upper platform 10 and the lower adapter plate 7 at the same time, and the lower adapter plate 9 is hinged to the upper platform 10 and the lower adapter plate 7 simultaneously. The adapter plate 7 is hinged to the lower platform 8 .

In this embodiment, the upper platform 10 is provided with an actuator 19 .

In order to better enable people to understand the solutions of the present invention, the technical solutions will be clearly and completely described below in conjunction with examples of the present invention, and the present invention is not limited to these examples.

Specific embodiment 1

Referring to Fig. 2, when the planar parallel mechanism 20, the pulley frame 3, and the bottom rod 1 rotate from the equilibrium position, the traction wire 4 stretches the elastic element 15 and deforms, generating a force against rotation, which can be converted into the stiffness of the wrist assembly 21 Stretching the elastic element 15 through the variable stiffness driver 18 can change the tension of the elastic element 15 to adjust the rotational stiffness of the wrist assembly 21, and at the same time install the actuator 19 on the upper platform 10 of the variable stiffness wrist assembly 21 for robot operations.

The present invention stretches the elastic element 15 through the variable stiffness driver 18 to increase the tension of the elastic element 15 to increase the stiffness of the wrist assembly 21, thereby avoiding deformation and oscillation during the movement of the robot and increasing the accuracy of the robot's positioning to the work object. During the object contact process, the stretching length of the elastic element 15 is adjusted by the variable stiffness driver 18 to reduce the tension of the elastic element 15, so that the stiffness of the wrist assembly 21 is reduced. At this time, the stiffness of the wrist assembly 21 becomes a compliant wrist. , automatically adjust the relative pose between the robot and the work object, and compensate the pose error to complete the work. Therefore, according to different procedures in the robot work process, the wrist assembly 21 can be adjusted to different stiffnesses in a large range in real time online.

Specific embodiment 2

Referring to Fig. 3, the plane parallel mechanism 20 can rotate around the rotating shaft 16 through the shaft hole on the bottom rod 1, and can also rotate around the rotation axis at the hinge of the connecting rod 2 and the pulley frame 3. The rotation axis of the plane parallel mechanism 20 , the rotation axis of the bottom rod 1 and the rotation axis of the pulley frame 3 are perpendicular to each other, and the plane parallel mechanism 20 can translate parallel to the rotation axis of the bottom rod 1 and the rotation axis of the pulley frame 3 respectively, so as to realize the wrist assembly 21 around the space 3 The rotation of the axis and the movement of 5 degrees of freedom along the two directions of the plane, so as to meet the requirements of robot attitude adjustment.

Specific embodiment 3

Referring to Fig. 4, the wrist assembly 21 with variable stiffness is installed on the industrial robot. According to different procedures in the robot operation process, the wrist assembly 21 can be adjusted to different stiffnesses in a large range in real time online. When the industrial robot moves to the operation object, The stiffness of the wrist assembly 21 is adjusted to a larger value to avoid deformation and oscillation during the movement of the robot, and to increase the accuracy of the positioning of the robot to the work object; There is jamming between the objects. At this time, the stiffness of the wrist assembly 21 is adjusted to a smaller value to become a compliant wrist. Under the action of the jamming resistance, the relative pose between the robot and the work object is automatically adjusted to compensate for pose errors. Operation.

The use method of the present invention is: install the wrist assembly 21 that can vary the rigidity in a wide range on the industrial robot. According to different procedures in the robot operation process, the wrist assembly 21 can be adjusted to different stiffnesses in a large range in real time online. When the industrial robot moves to During the process of working on the working object, the stiffness of the wrist assembly 21 is adjusted to a larger value to avoid deformation and oscillation during the movement of the robot, and increase the accuracy of the robot's positioning to the working object; error, there is jamming between the robot and the work object, at this time the stiffness of the wrist assembly 21 is adjusted to a smaller value to become a compliant wrist assembly 21, and under the action of the jamming resistance, the relative pose between the robot and the work object is automatically adjusted to compensate Pose errors to complete the homework.

The present invention can install the wrist assembly 21 with variable stiffness in a wide range on the industrial robot. According to different procedures in the robot's operation process, the wrist assembly 21 can be adjusted to different stiffnesses in a large range in real time online. When the industrial robot moves to the operation object , the stiffness of the wrist assembly 21 is adjusted to a larger value to avoid deformation and oscillation during the robot’s movement, and to increase the accuracy of the robot’s positioning to the work object; There is jamming between the work objects. At this time, the stiffness of the wrist assembly 21 is adjusted to a smaller value to become a compliant wrist assembly 21. Under the action of the jamming resistance, the relative pose between the robot and the work object is automatically adjusted to compensate for pose errors. to complete the assignment.

On the premise of no conflict, those skilled in the art can freely combine and superimpose the above additional technical features.

The above descriptions are only the preferred implementation modes of the present invention, as long as the technical solutions to achieve the purpose of the present invention by basically the same means fall within the scope of protection of the present invention.

Claims (4)

1. The utility model provides a robot wrist of variable rigidity on a large scale which characterized in that: the variable stiffness driving device comprises a variable stiffness driving device (18) and a wrist assembly (21), wherein a rotating shaft (16) is arranged on the variable stiffness driving device (18), an elastic element (15) is arranged on the rotating shaft (16), mounting rods (17) are arranged on two sides of the elastic element (15), the mounting rods (17) are fixedly arranged on the variable stiffness driving device (18), the wrist assembly (21) comprises a top rod (5), a pulley frame (3), a bottom rod (1) and a connecting rod (2), the bottom rod (1) is arranged between the variable stiffness driving device (18) and the mounting rods (17), a shaft hole through which the rotating shaft (16) penetrates is formed in the bottom rod (1), the bottom rod (1) is fixedly connected with the connecting rod (2), the connecting rod (2) is hinged with the pulley frame (3), pulleys are arranged on the pulley frame (3), the top rod (5) is fixedly connected with the top rod (5), a plane parallel mechanism (20) is arranged on the top rod (5), the plane parallel mechanism (20) comprises an upper platform (10), a lower platform (8) and a branched chain structure (6) and a plurality of groups of upper and lower platforms (8) and a branched chain structure (6) are arranged on the connecting rod (2) and a branched chain structure ) The cable fixing device is characterized in that a gap is formed between the limiting columns (6), a cable column (14) is arranged on the upper platform (10), a traction cable (4) is arranged on the cable column (14), one end of the traction cable (4) is fixed on the cable column (14), and the other end of the traction cable (4) penetrates through the limiting columns (6) and the pulley to be connected with the elastic element (15) respectively.

2. A wide range of varying stiffness robot wrist according to claim 1, wherein: the upper platform (10) and the lower platform (8) are also provided with a limiting assembly, the limiting assembly comprises an upper limiting block (13) and a lower limiting block (12), and the upper limiting block (13) and the lower limiting block (12) are respectively hinged to the upper platform (10) and the lower platform (8).

3. A widely varying stiffness robot wrist according to claim 1, wherein: the branched chain structure comprises an upper connecting plate (9) and a lower connecting plate (7), the upper connecting plate (9) is hinged to the upper platform (10) and the lower connecting plate (7), and the lower connecting plate (7) is hinged to the lower platform (8).

4. A wide range of varying stiffness robot wrist according to claim 1, wherein: an actuator (19) is arranged on the upper platform (10).

Images