EP3849752A1

EP3849752A1 - Robot unit, in particular delta robot, having rotatable arms

Info

Publication number: EP3849752A1
Application number: EP18810922.7A
Authority: EP
Inventors: Nicola Maria CERIANI
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2018-11-15
Filing date: 2018-11-15
Publication date: 2021-07-21
Also published as: US20220009081A1; WO2020098944A1; CN113015601A

Abstract

The invention relates to a robot unit (1) having - a base (2), - an effector unit (8), - at least two connecting arms (3) for connecting the base and the effector unit (8), and - a base motor (10) for each of the at least two connecting arms (3) in order to move the respective connecting arms relative to the base, wherein - a first arm part (4) of each of the at least two connecting arms (3) is arranged on the base (2) and a second arm part (5) of each of the at least two connecting arms (3) is arranged on the effector unit (8), and wherein - each first arm part (4) and its associated second arm part (5) are movably connected to each other by a connecting element (13). In order to allow improved movability for the effector unit (8), according to the invention, - the at least two connecting arms (3) each have a pivot bearing (15), wherein the pivot bearings (15) each allow rotation of at least one component (7) of the arm parts (4, 5) about an axis of rotation (20) oriented parallel to its direction of extension.

Description

description

Robot unit, in particular delta robot, with rotatable arms

The invention relates to a robot unit, in particular a so-called parallel arm robot or delta robot.

Robot units are used for different activities, especially on an industrial scale. Parallel arm robots or so-called delta robots are common for so-called handling tasks. Handling tasks are sometimes also referred to as “pick-and-place applications”. Examples of this are placing components on a workpiece in a production line or arranging or stacking products in packaging.

Parallel arm robots are referred to as parallel, since between a base of the parallel arm robot and an effec tor unit, several connecting arms are arranged in parallel. In this context, parallel generally does not mean that the connection-poor connections run geometrically parallel. Instead, it describes in parallel the property that the connecting arms are each arranged between the same components of the robot unit, namely the base and the effector unit, in particular in each case in the same way. This is to be understood in particular in contrast to a robot arm with several arms arranged in series.

A tool suitable for a particular task can be arranged on the effector unit. In particular, the effector unit has a corresponding fastening unit for arranging a tool.

Parallel arm robots can be used effectively for handling tasks because they enable high speeds can and therefore can carry out a comparatively high number of work steps ("picks") per unit of time.

Disadvantages of parallel arm robots are the restricted movements due to their structure.

The object of the present invention is to enable improved mobility for an effector unit of a robot unit.

This object is achieved by the subject matter of the independent claims. Advantageous embodiments with appropriate further developments are the subject of the dependent claims.

The invention is based on a robot unit

- a base,

- an effector unit,

- At least two connecting arms for connecting the base and the effector unit, and

a respective base motor for each of the at least two connecting arms for moving the respective connecting arm relative to the base, wherein

- A respective first partial arm of the at least two connecting arms on the base and a respective second partial arm of the at least two connecting arms on the effector unit is arranged, and wherein

- The respective first and the respective second arm are movably connected to one another by a connecting element.

In order to enable improved mobility of the effector unit, it is provided that the at least two connecting arms each have a rotary bearing, the rotary bearings each rotating at least one component of the partial arms about an axis of rotation which is oriented parallel to its direction of extension. enable. The base can be a part of the robot unit that is arranged on a higher-level component of a system during normal operation of the robot unit. It is essentially provided that the robot unit executes work steps by moving the effector unit relative to the base. In the case of a handling task, it is provided, for example, that control or movement of the effector unit between a starting position and a target position is provided for components to be moved. A fastening unit can be arranged on the effector unit, which enables the arrangement of a tool on the basis of the effector unit. In principle, all conceivable tools are conceivable, for example for material processing (for example drills), clock shaping (for example extruders of a 3D printer) or material movement (for example grippers). For handling tasks, tools for material movement, in particular grippers, are in particular on the effector unit

can be arranged.

A relative movement between the base and effector unit can be controlled or carried out by moving the at least two connecting arms. In particular, the movement or position of the at least two connecting arms is controlled relative to the base by means of the respective base motors. In other words, the respective base motors are designed to position or move the at least two connecting arms. By positioning or moving the at least two connecting arms, the respective base motors can indirectly influence the relative position between the base and the effector unit.

The at least two connecting arms each have the first and second partial arms. The at least two connecting arms can also have further partial arms. The connecting arms can alternatively consist exclusively of the first and the second partial arm. The second partial arms can each be attached by means of a respective rotary bearing the effector unit. The respective rotation bearings can have exactly two degrees of freedom. The first partial arms can each be arranged on the base by means of a respective rotary bearing. The respective rotary bearings can each have exactly one degree of freedom. The first partial arm and the second partial arm of a respective connecting arm are each connected to one another via the connecting element. The connecting elements can be a respective joint or a respective rotary bearing. The connecting elements can each have exactly one or preferably exactly two degrees of freedom.

Due to the respective pivot bearing, the partial arms can rotate at least partially around the rotation axis mentioned. For example, the rotary bearings allow the respective partial arms to rotate within themselves. For example, the rotary bearings enable the respective first partial arm or the respective second partial arm to rotate. A rotary movement of the effector unit is made possible by the rotary bearings or the rotation of the respective partial arms. For example, the effector unit can be tilted or inclined relative to the base by a corresponding rotational movement of all the partial arms. This enables improved mobility of the effector unit relative to the base.

All connecting arms of the robot unit can be of the same type. In other words, all connecting arms of the robot unit can have the same technical structure. In this case, the only difference between the different connecting arms is their positioning at the base and the effector unit. For example, the connecting arms are each arranged at a constant angle with respect to the base. In the case of three connecting arms, these are each arranged, for example, rotated through 120 ° on the base. According to a further development, it is provided that the first partial arms are rotatably arranged on the base via a respective rotary bearing. In other words, the first partial arms are rotatably arranged on the base. For example, a respective partial arm can have exactly one degree of freedom relative to the base due to the rotary bearing. In this way, advantageous control of the robot unit can be made possible.

According to a further development, it is provided that the first and the second partial arm of a respective one of the at least two connecting arms can be pivoted relative to one another by the respective connecting element, in particular particularly exclusively. In other words, the first and the second partial arm of a respective connecting arm can only rotate relative to one another. A translatory relative movement can thus be prevented by the respective connecting element. In particular, the first and the second partial arm of a respective connecting arm can be pivoted relative to one another exclusively with respect to exactly one degree of freedom or with respect to exactly two degrees of freedom. The exactly two degrees of freedom can each be a relative rotation with respect to exactly two independent solid angles. In this way, a particularly advantageous mobility of the robot unit is made possible.

According to a development, it is provided that the at least two connecting arms each have at least one arm motor for performing the rotation of the at least one component. The arm motors can be arranged on the respective connection arms. A respective degree of freedom of the robot unit can be actuated by the arm motors. In particular, the rotation of the at least one component of the respective arm is actuated by the arm motors. In this way, newly gained degrees of freedom can be controlled by the pivot bearing. According to a further development it is provided that the arm motors are arranged inside the respective first or second arm. In other words, the arm motor of a respective connecting arm can be completely or partially enclosed by the first or second part arm of the corresponding connecting arm. For example, the respective partial arm can have a cavity in which the respective arm motor is arranged. In this way, the arm motors can be arranged on the robot unit in a particularly space-saving and reliable manner. In addition, this form of arrangement allows an inertia of the connecting arms to be kept low, which benefits a working speed of the robot unit.

According to different embodiments, it can be provided that the first partial arms and / or the second partial arms rotate in themselves.

Accordingly, it is provided by way of example that the first partial arms are each divided into two links and the rotary bearings each enable rotation of one of the links relative to the other of the links as rotation of the component of the partial arms. For example, a first of the links can be fixed to the base by means of the respective rotary bearing of the corresponding partial arm.

Alternatively or additionally, it is provided that the second partial arms are each divided into two links and the rotary bearings each enable rotation of one of the links relative to the other of the links as a rotation of the component of the partial arms. For example, the first link is arranged on the first partial arm by means of the respective connecting element, and the second link can be rotatably supported by the pivot bearing relative to the first link.

In the above-mentioned embodiments, one of the links represents the component of the respective partial arm, the rotation of which is made possible by the respective pivot bearing. In particular in particular, each of the first / second arms is divided into two respective links. With each of the first / second partial arms, a respective rotary bearing enables the respective rotation of one of the links relative to the other of the links. The two links each are connected to each other, for example, exclusively via the pivot bearing. For example, one of the links in the pivot bearing, which is fixedly arranged on the other link, is rotatably mounted.

According to a development, it is provided that the arm motors are each arranged on a first of the links and are connected to a second of the links along a shaft along the direction of extension of the respective partial arm. In other words, the respective arm motor of a partial arm can be arranged on the first of the links. In particular, the respective arm motor is arranged on a side of the first link facing away from the second link. The respective shaft can then be guided from the arm motor or from the side facing away from the second link to the second link. In this way, the arm motor can be positioned as close as possible to the base, thereby reducing the moment of inertia.

It can in particular be provided that the waves are passed through the first link, in particular through a tunnel of the respective first link. For example, the first links form the tunnel for the respective wave. For example, the respective shaft can be guided through the tunnel from the arm motor or from the side of the first link facing away from the second link to the second link. In this way, a particularly compact design can be achieved.

According to a further development, it is provided that the rotary bearings are each formed by one of the two links. In other words, the respective pivot bearing of one of the partial arms can be formed by the respective first link. In particular, the respective pivot bearing is through the respective tunnel of the first limbs. This allows an even more compact design to be achieved.

According to a development, it is provided that a respective axis of rotation of the rotary bearings is oriented parallel to a main direction of extension of the links of the respective partial arm. In general, the respective rotation of the at least one component of the partial arms can run parallel to the direction of extension. In particular, the rotation axis of the rotary bearings or the rotation of the links runs parallel to the first and / or the second link. This results in a particularly compact geometric structure of the robot unit.

According to a development, it is provided that the links of each of the partial arms are connected by the pivot bearing at an extended angle (180 °). This applies in particular to a respective main direction of extension of the limbs of a respective arm. The first link and the second link of a respective partial arm can run parallel to one another, in particular with respect to the respective direction. In addition, the second link can connect directly to the first link. In other words, the second link can be a straight extension of the first link. As already mentioned above, the second link can be at least partially enclosed by the first link. In this case, the first link can form the pivot bearing for the second link. In this way, an even more compact design can be achieved.

According to a further development, the robot unit has a control unit which is designed to control a rotation of the respective first partial arm or the respective second partial arm in such a way that an angle between the base and the effector unit is changed. For example, the control unit is set up for this purpose to control the arm motors and / or the base motors. By controlling the arm motors and / or the base motors, one can corresponding movement of the connecting arms who caused the. A corresponding movement of the effector unit follows from the movement of the connecting arms. In this way, the position of the effector unit relative to the base can be changed by means of the control unit. For example, the effector unit can be inclined relative to the base.

According to a further development, it is provided that the robot unit has exactly three connecting arms. In particular, the three connecting arms are designed in the same way. The three connecting arms can correspond to the above-mentioned at least two connecting arms. The three connecting arms can each be arranged at an angle of 120 ° at the base. Three connecting arms have proven to be a particularly successful compromise for the robot unit.

According to a further development, it is provided that the robot unit has exactly six actuated or motorized degrees of freedom. This is particularly advantageous if the robot unit has exactly three connecting arms. The six actuated degrees of freedom can then be divided between the three arm motors and the three base motors of the three connecting arms. In this way, the three connecting arms can be driven in a particularly useful manner.

The above-described properties, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the exemplary embodiments, which will be explained in connection with the drawings. This description does not limit the invention to these exemplary embodiments. In different figures, the same components are provided with identical reference numerals. The figures are generally not to scale. Show:

1 shows a schematic perspective view of a first

Embodiment of a robot unit;

2 shows a schematic exploded view of a partial arm of the first embodiment of the robot unit;

3 shows a schematic overview of axes of rotation of the

first embodiment of the robot unit;

4 shows a schematic overview of degrees of freedom of an effector unit of the first embodiment of the robot unit;

5 shows a schematic perspective view of a second one

Embodiment of a robot unit;

6 shows a schematic exploded view of a partial arm of the second embodiment of the robot unit;

7 shows a schematic overview of axes of rotation of the

second embodiment of the robot unit; and

8 shows a schematic overview of degrees of freedom of an effector unit of the second embodiment of the robot unit;

1, 3 and 4 and 5, 7 and 8 each show a robot unit 1 in different embodiments. The robot unit 1 has a base 2 on which three connecting arms 3 are arranged. The connecting arms 3 are each arranged on the base 2 rotated by 120 °. The connecting arms 3 each have a first partial arm 4 and a second partial arm 5. The first partial arms 4 are rotatably supported on the base 2 via a respective rotary bearing 12. The first arm 4 and the second Partial arm 5 of each of the connecting arms 3 are connected to one another via a respective connecting element 13. The second partial arms 5 are rotatably mounted on an effector unit 8 via a respective rotary bearing 14. Since the connecting arms 3 are ever arranged in a similar manner between the base 2 and the effector unit 8, the robot unit 1 is also referred to as a parallel arm robot or as a so-called delta robot. The effector unit 8, also called effector, has a tool holder (not shown in the figures), by means of which a tool, in particular a gripper, can be arranged on the effector unit 8.

The first partial arms in FIG. 4 are the partial arms arranged directly on the base 2. The second partial arms 5 are the partial arms which are further away from the base 2. The partial arms 5 are thus arranged between the first partial arms 4 and the effector unit 8.

The first partial arms 4 are relative to the base 2 each bezüg Lich exactly one axis of rotation 21 rotatably or pivotally mounted. In other words, the partial arms 4 can only move in a respective plane and rotationally about the respective rotary bearing 12. With their words again, each of the partial arms 4 are blocked relative to the base 2 by six degrees of freedom (three translational, three rotary) all but one rotary degree of freedom by the respective rotary bearing 12.

The second part arms 5 are rotatably or pivotably mounted relative to the respective first part arm 4 of the same connecting arm 3 with respect to exactly two axes of rotation. In other words, a movement of the second partial arms 5 relative to the respective partial arm 4 can only take place along a respective spherical sphere and only rotationally around the respective connecting element 13. In other words, for each of the second partial arms 5 relative to the respective partial arm 4 of six degrees of freedom (three translatory, three rotary) are all but two rotary Degrees of freedom blocked by the respective connecting element 13 ge.

The second partial arms 5 are arranged on the effector unit 8 by means of a respective rotation bearing 14. The second sub-arms 5 are relative to the effector unit 8 each with respect to exactly two axes of rotation rotatably or pivotally mounted. In other words, a movement of the second partial arms 5 relative to the effector unit 8 can only take place along a respective spherical sphere and only rotationally around the respective rotary bearing 14. In yet other words, for each of the second partial arms 5 relative to the effector unit 8 of six degrees of freedom (three translatory, three rotary) all but two rotational degrees of freedom are blocked by the respective rotary bearing 14.

The effector unit 8 can be moved by appropriate movement of the connecting arms 3. For this purpose, the ro robot unit 1 has a respective base motor 10 for each of the connecting arms 3. In the present exemplary embodiment, the base motor 10 is arranged on the base. The respective base motors 10 enable the connecting arms 3 or the partial arms 4 to move with respect to the respective rotation axis 21. The axes of rotation 21 are shown in FIG. 3 and FIG.

In addition, in both exemplary embodiments of the robot unit 1, individual ones of the partial arms 4, 5 are rotatable in themselves. For this purpose, one of the partial arms 4, 5 of a respective Ver connecting arm 3 has a respective pivot bearing 15.

According to the first exemplary embodiment in FIGS. 1 to 4, the second partial arms 5 of each of the connecting arms 3 are divided into two segments 6, 7. This exemplary embodiment will be dealt with first: Such a second arm 5 is shown in FIG. 2 in a schematic exploded view. A first link 6 has part of the connection elements 13 for connection to the respective first partial arm 4. A second link 7 has a part of the Rotationsla gers 14 for connection to the effector unit 8. With their words, the first link 6 is arranged on the first partial arm 4 in the assembled state. In contrast, the second link 7 is arranged in the assembled state on the effector unit 8.

In the present case, the first link 6 forms the pivot bearing 15. The first link 6 is partially hollow. This results in a tunnel in the middle of the first link 6. The second link 7 is partially inserted in this tunnel. The pivot bearing 15 is thus provided through this tunnel. A shaft 16 is through the tunnel through the first link 6 leads ge. The shaft 16 connects an arm motor 11 with the two-th link 7. The arm motor 11 is arranged on a side of the first link 6 facing away from the second link 7. In other words, the arm motor 11 and the second link 7 are essentially objected to by the first link 6.

The pivot bearing 15 provides a further degree of freedom for each connecting arm 3. These degrees of freedom are controlled or actuated by the respective arm motor 11. The rotary bearing 15 provides a rotational degree of freedom along an axis of rotation 20 (see FIG. 3). A translatory movement of the first member 6 and the second member 7 relative to each other can be prevented by the pivot bearing 15. The rotation about the axis of rotation 20 is controlled or actuated by the respective arm motor 11 arranged on the first link 6.

According to the second exemplary embodiment in FIGS. 5 to 8, the first partial arms 4 of each of the connecting arms 3 are divided into two members 6, 7. This exemplary embodiment will be discussed below: Such a first partial arm 4 is shown in FIG. 6 in a schematic exploded view. A first link 6 has part of the rotational position. gers 12 for connection to the base 2. A second link 7 has a part of the connecting element 13 for connection to the respective second arm 5 of the respective connec tion arm 3. In other words, the first link 6 is arranged on the base 2 in the assembled state. In contrast, the second link 7 is in the assembled state on the connec tion element 13 and the second arm 5 is arranged.

In the present case, the first link 6 forms the pivot bearing 15. The first link 6 is partially hollow. This results in a tunnel 22 in the middle of the first link 6. The second link 7 is partially inserted in this tunnel 22. The pivot bearing 15 is thus provided through this tunnel 22. In addition, an arm motor 11 is also arranged in this tunnel 22. The arm motor 11 can be arranged directly on the second link 7. For example, the arm motor 11 is connected to the second link 7 via a shaft 16.

The pivot bearing 15 provides a further degree of freedom for each connecting arm 3. These degrees of freedom are controlled or actuated by the respective arm motor 11. The rotary bearing 15 provides a rotational degree of freedom along an axis of rotation 20 (see FIG. 7). A translatory movement of the first member 6 and the second member 7 relative to each other can be prevented by the pivot bearing 15. The rotation about the axis of rotation 20 is controlled or actuated by the respective arm motor 11 arranged on the first link 6.

The respective degrees of freedom x, y, z, cx, β, Y of the effector unit 8 are shown in FIGS. 4 and 8. These differ only slightly between the embodiments. The six degrees of freedom along the Rotationach sen 20 and 21 allow movement of the effector unit 8 ent along all six possible degrees of freedom x, y, z,, ß, g (three translational, three rotary). By Corresponding control of the arm motors 11 and the base motor 10, movement of the effector unit 8 along all six degrees of freedom x, y, z,, ß, g is possible. The robot unit 1 can have a control unit 19 which is set up for such a control.

Where this has not yet been done explicitly, but is sensible and in the spirit of the invention, individual exemplary embodiments, some of their partial aspects or features, can be combined or exchanged with one another without leaving the scope of the present invention. Advantages of the invention described with reference to an exemplary embodiment also apply to other exemplary embodiments without explicit mentioning, where transferable.

Reference symbol list

1 robot unit

2 base

3 connecting arms

4 branches

5 branches

6 links

7 link

8 effector unit

10 base engine

11 arm motor

12 rotary bearings

13 connecting element

14 rotary bearings

15 pivot bearings

16 wave

19 control unit

20 axis of rotation

21 axis of rotation

22 tunnels

x, y, z,, b, g degrees of freedom

Claims

1. Robot unit (1) with

- a base (2),

- an effector unit (8),

- At least two connecting arms (3) for connecting the base and the effector unit (8), and

- A respective base motor (10) for each of the at least two connecting arms (3) for moving the respective connec tion arm relative to the base, wherein

- A respective first partial arm (4) of the at least two Ver connecting arms (3) on the base (2) and a respective second partial arm (5) of the at least two connecting arms (3) is arranged on the effector unit (8), and wherein

the respective first partial arm (4) and the respective second partial arm (5) are movably connected to one another by a connecting element (13),

characterized in that

- The at least two connecting arms (3) each have a rotary bearing (15), the rotary bearings (15) each having a rotation of at least one component (7) of the partial arms (4, 5) about an axis of rotation (20) which is parallel to is oriented in its direction of extension.

2. Robot unit (1) according to claim 1, characterized in that the first partial arms (4) via a respective rotation bearing (12) are rotatably arranged on the base (2).

3. Robot unit (1) according to one of the preceding claims, characterized in that the first and the second partial arm (4, 5) of a respective one of the at least two connecting arms (3) by the respective connecting element (13), in particular exclusively, relatively are pivotable to each other.

4. Robot unit (1) according to one of the preceding claims, characterized in that the at least two connecting arms (3) each have at least one arm motor (11) Have the rotation of the at least one component (7).

5. Robot unit (1) according to claim 4, characterized in that the arm motors (11) in the interior of the respective first or second arm (4, 5) are arranged.

6. Robot unit (1) according to one of the preceding claims, characterized in that the first partial arms (4) are each divided into two links (6, 7) and the rotary bearings (15) each have a rotation of one of the links (7) relative to the other of the links (6) as rotation of the component (7) of the partial arms (4).

7. Robot unit (1) according to one of the preceding claims, characterized in that the second partial arms (5) are each divided into two links (6, 7) and the rotary bearings (15) each have a rotation of one of the links (7) relative to allow the other of the links (6) as rotation of the component (7) of the partial arms (5).

8. Robot unit (1) according to claim 4 and one of claims 6 or 7, characterized in that the arm motors (11) are each arranged on a first of the links (6) and along a shaft to the direction of extension of the respective partial arm (4, 5) are connected to a second of the links (7).

9. Robot unit (1) according to claim 8, characterized in that the shafts (16) are guided through the first link (6), in particular through a tunnel (22) of the respective first link (6).

10. Robot unit (1) according to one of claims 6 to 9, characterized in that the rotary bearings (15) are each formed by one of the two members (6, 7).

11. Robot unit (1) according to any one of claims 6 to 10, characterized in that a respective axis of rotation (20) of the rotary bearing is aligned parallel to a main direction of extension of the links (6, 7) of the respective partial arm (4, 5) .

12. Robot unit (1) according to one of claims 6 to 11, characterized in that the links (6, 7) of a respective gene of the partial arms (4, 5) by the pivot bearing (15) at a ge extended angle (180 ° ) are connected.

13. Robot unit (1) according to one of the preceding claims, characterized by a control unit (19) designed to control a rotation of the respective first partial arm (4) or the respective second partial arm (5) such that an angle between the base (2) and the effector unit (8) is changed.

14. Robot unit (1) according to one of the preceding claims, characterized in that the robot unit (1) has precisely three connecting arms (3).

15. Robot unit (1) according to one of the preceding claims, characterized in that the robot unit (1) has exactly six actuated degrees of freedom (20, 21).