CN110914020A

CN110914020A - Manipulating device with robot, method and computer program

Info

Publication number: CN110914020A
Application number: CN201880051203.XA
Authority: CN
Inventors: F.伯伊克; S.耶森; S.阿拉塔塞夫
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-08-07
Filing date: 2018-06-13
Publication date: 2020-03-24
Anticipated expiration: 2038-06-13
Also published as: WO2019029870A1; KR20200038468A; JP7003220B2; CN110914020B; JP2020529931A; KR102553391B1; DE102017213651A1

Abstract

Robots with multiple arms are increasingly used in industrial production. An actuating device is proposed, which: having a robot (2), wherein the robot (2) has a plurality of kinematic chains (4 a, 4 b), wherein each kinematic chain (4 a, 4 b) is movable in a working space, wherein at least two working spaces of the working spaces have an overlap, wherein each kinematic chain (4 a, 4 b) is designed to carry out a work movement, having a control module for actuating the kinematic chains (4 a, 4 b) in order to carry out a total movement, wherein the total movement can be generated by the work movement of the kinematic chains (4 a, 4 b), wherein the control module is designed to carry out a trajectory function (q)₁、q₂) On the basis of the control of the kinematic chain,for carrying out said work motion; having a trajectory determination module and a reparameterization module, wherein the trajectory determination module is designed to determine a respective trajectory function (q) for each work motion of the kinematic chain (4 a, 4 b)₁、q₂) Minimum time trajectory (q)₁(τ₁)、q₂(τ₂) Wherein the reparameterization module is configured to correct the minimum time trajectory (q) based on the minimum time trajectory (q)₁(τ₁)、q₂(τ₂) Track function (q)₁、q₂) The reparameterization is performed such that the total motion is collision-free.

Description

Manipulating device with robot, method and computer program

Technical Field

A handling device is proposed, which has a robot, wherein the robot has a plurality of kinematic chains, wherein each of the kinematic chains is movable in a working space, wherein at least two of the working spaces have an overlap, wherein each of the kinematic chains is designed to execute a working movement; the control module is provided for actuating the kinematic chain for carrying out a total movement, wherein the total movement can be represented by a working movement of the kinematic chain. Furthermore, a method for operating a robot and a computer program are proposed.

Background

The use of robots in process automation and in particular in industrial manufacturing is known from the prior art.

Document DE 102013014287 Al, which may constitute the latest prior art, describes a method for joining precision mechanical components by laser welding, having the following steps: gripping a first member from a first magazine area with a first gripper provided on a first robot arm; gripping a second component from a second magazine area with a second gripper provided on a second robot arm in order to hold the first component with a first gripper; and holding the second members in the first set position with respect to each other and to the laser device with a second gripper; activating the laser device and connecting the first and second members to each other in a first assembly position for assembly by means of a first welded connection; the assembly is placed in the storage area by means of the first gripper.

Disclosure of Invention

A handling device with a robot is proposed with the features of claim 1. Furthermore, a method for operating a robot, in particular a robot for a handling device, having the features of claim 11 and a computer program having the features of claim 12 are proposed. Further advantages and effects emerge from the dependent claims of the description below.

A manipulator with a robot is proposed. In particular, the handling device is a device of industrial automation technology. Such as a robotic work site, a manufacturing site, and/or an assembly site. The robot is preferably designed to carry out assembly steps and/or production steps. In particular the robot is a single-arm robot, a two-arm robot or a multi-arm robot. Further, the robot can be an articulated arm robot. In particular, the robot is designed as a multi-axis robot. In particular, the handling device can have a plurality of robots.

The robot has a plurality of kinematic chains. In particular, the robot has exactly two or more kinematic chains. In particular the robot can have more than five and/or more than ten kinematic chains. Preferably the robot has an end effector at the end of the kinematic chain. Each of the kinematics chains is capable of moving in the workspace. In particular, the end effector can be moved in a working space. The workspace is in particular a three-dimensional space. Preferably, each point of the workspace can be reached by a kinematic chain and/or by an end effector. At least two of the workspaces have an overlap. The overlap can completely comprise one and/or two workspaces.

The kinematic chain is configured to implement a work motion. The work movement is used, for example, to carry out production and/or assembly steps. The working movement can be, for example, an approach of a point and/or a coordinate with the end effector.

The manipulator and/or the robot has a control module for actuating the kinematic chain. In particular, the control module is designed to independently actuate the kinematic chains. The actuation of the kinematic chain is used in particular to carry out a working movement. The total motion can be represented by the work motion of the kinematic chain. In particular, the total movement is the result of the sequential execution and/or the combined result of the working movements of the kinematic chain. The total movement can be a synchronous movement of the kinematic chain, for example a double-arm lifting or an equipment-free assembly. Alternatively, the overall movement is an asynchronous movement of the kinematic chain, for example, the different kinematic chains are used to grip different workpieces one after the other.

The control module is designed to control the kinematic chain on the basis of the trajectory function in order to carry out a work movement. The trajectory function is in particular a vector valued function. For example, the kinematic chain comprises a number n of movable joints, wherein the associated trajectory function is a vector having n entries, wherein each entry specifies an angular position of the associated joint. Furthermore, the trajectory function can also include the adjustment speed and the adjustment acceleration of the joint in addition to the angular position. The control module is preferably designed to act in a discrete manner as a target value generator for the kinematic chain and/or the joint.

The manipulator includes a trajectory determination module and a re-parameterization module. In particular, the trajectory determination module and the reparameterization module can be part of the control module. The control module, the trajectory determination module and/or the reparameterization module is for example a computer unit, a processor or a microchip.

The trajectory determination module is configured to determine a minimum time trajectory as a trajectory function for each work motion of the work motions of the robot and/or each work motion of the kinematic chain, respectively. In particular, the trajectory determination module is designed to: a minimum time trajectory is determined for each of the kinematics chains of the robot without depending on the other kinematics chains of the robot.

The reparameterization module is configured to reparameterize the trajectory function on the basis of a minimum time trajectory. In particular, the reparameterized trajectory function is designed to cause the kinematic chain to execute a working movement in such a way that the overall movement is collision-free. Preferably, the control module is designed to control the kinematic chain on the basis of the reparameterized trajectory function.

The invention is based on the consideration that: an automated handling device with a robot is provided, which is able to perform its tasks without collision. The advantage over the prior art is, for example, that symbolic planning can be used at a higher level of abstraction. Furthermore, the error-prone and time-consuming manual coordination of the kinematic chain can be eliminated. Through the use of the control module, collision-free planned movements and/or processes of the robot are ensured. This has the advantage that the inherently asynchronous movements do not have to be synchronized manually beforehand.

In one possible embodiment of the invention, it is provided that the kinematics chain, the kinematics chains and/or all kinematics chains are each designed as a robot arm and/or as a manipulator. The robot arm is configured to perform mechanical work. For example, handling tasks, such as welding, splitting or other manufacturing methods, can be performed by means of the robot arm. In particular, the robot arm is designed for carrying out positioning tasks and/or measuring tasks. For example, the robot arm includes a gripper as an end effector. Preferably, the robot arm comprises a plurality of rotational and/or thrust shafts for performing the working movement.

It is particularly preferred that the minimum time trajectory is a trajectory function that requires the least time to perform a work motion. In particular, the minimum time trajectory is a trajectory function which, for a given path, is reparameterized with a function in such a way as to take into account the dynamics (kinodynamisch) constraints of the robot and/or the kinematic chain, so that overall a minimum execution time duration is produced for the working movement.

Optionally, it is provided that the trajectory determination module is configured to: the minimum time trajectory is determined on the basis of a limited maximum acceleration and/or a limited maximum velocity of one of the kinematic chains and/or joints. In particular, a limited adjustment speed and/or a limited adjustment acceleration of the kinematic chain and/or joint is understood as a dynamic limitation.

In one possible embodiment of the invention, it is provided that the reparameterization module is designed to reparameterize the total movement with a global time curve. In particular, it is provided that for robots with a number x of kinematic chains, the global time curve is a curve in an x-dimensional space, in particular in R^xCurve (2) in (c). The global time curve can be described, in particular, by means of a point element (Punktetupel), wherein each entry in this point element corresponds to a time instant on the minimum time trajectory of the kinematic chain. In this case, the point elements in particular assign points in time and/or positions on different minimum time trajectories to one another.

In a particularly preferred embodiment of the invention, it is provided that the minimum time trajectory is described by the trajectory determination module by means of an intrinsic time. In particular, the inherent time extends from a start time to an end time, wherein the inherent time determines where the kinematic chain is located on a minimum time trajectory between the start time and the end time.

The reparameterization module includes a check function. The check function has a minimum time trajectory as a function argument. The check function assigns as an output, in particular, a "collision of the kinematic chain" or a "collision-free nature of the kinematic chain" on the basis of the function argument. For example, the checking function outputs a value a as a function value in the event of a collision of the kinematic chain, where a is, for example, 1, and the checking function outputs a value b as a function value in the event of a collision of the kinematic chain, where b is, for example, 0. The reparameterization module is configured to divide the subspace into a collision space and an effective space. The subspace is spanned by the inherent time of the kinematic chain. For example the robot has a number x of kinematic chains, wherein the subspace is an x-dimensional subspace. The reparameterization module is in particular designed to: points in the subspace are assigned to the collision space if a collision of the kinematic chain has been detected and/or the check function output value a.

Furthermore, the reparameterization module is configured in particular to: points in the subspace are assigned to the active space if no collision of the kinematic chain is detected and/or the check function output value b. The reparameterization module is preferably designed to determine the curve in the effective space as a global time curve. In particular, the global time curve has no points in the collision space.

Optionally, it is provided that the total movement starts at a starting point and ends at an end point. The starting point is preferably a point in the working space, wherein a time coordinate can be assigned to the starting point in the subspace. The time coordinate of the start point in the subspace corresponds in particular to the zero point of the minimum time trajectory of the kinematic chain in the subspace. The end point is preferably a point in the working space, wherein a time coordinate can be assigned to the end point in the subspace. The temporal coordinate of the end point in the subspace corresponds in particular to the end point of the minimum temporal trajectory of the kinematic chain in the subspace. The reparameterization module is configured to: the shortest connection between the time coordinate of the start point and the time coordinate of the end point is determined as a global time curve.

Alternatively and/or additionally, it is provided that the fastest connection between the time coordinate of the start point and the time coordinate of the end point is determined by the reparameterization module as a global time curve.

Particularly preferably, the control module is designed to: the minimum time path for the reparameterization is converted for the operation of the robot by means of an inverse kinematics mechanism. In particular, the robot or the control mechanism of the robot is based entirely on inverse kinematics.

A particularly preferred embodiment of the invention provides that the total movement comprises an asynchronous working movement of at least two kinematic chains. The asynchronous work motion is, for example, a sequential gripping of the workpiece by two different robot arms and/or kinematic chains.

A method for operating a robot forms another subject of the invention. In particular the method is configured for operating a robot with a handling device according to any of the preceding claims. The method provides for determining a minimum time trajectory for each kinematic chain of the robot. The minimum time trajectory is designed in particular to describe a working movement of the kinematic chain. According to the method, the trajectory function based on the minimum time trajectory is re-parameterized in such a way that the overall movement of the kinematic chain is collision-free.

A computer program having program code sections for carrying out the above-described method when said computer program is executed on a computer or an operating device forms a further subject matter of the invention.

Drawings

Further features, advantages and effects of the invention result from the following description of preferred embodiments of the invention and from the drawings. Here:

fig. 1 shows an operating device as a first embodiment;

FIG. 2 illustrates one embodiment of a subspace;

FIG. 3 illustrates a subspace having a collision space and an effective space;

FIG. 4 shows a subspace with a global time curve;

fig. 5 shows a subspace with a global time curve and a plotted trajectory function.

Detailed Description

Fig. 1 shows a handling device 1 with a robot 2 as an exemplary embodiment of the invention. The handling device 1 is the installation site of the production facility. The robot 2 is designed for machining and/or assembling an object 3, for example a workpiece. Here, the robot 2 can grip, transport, and process the object 3.

The robot 2 has a first kinematic chain 4a and a second kinematic chain 4 b. The first and

second kinematics chains

4a, 4b are each configured as a robot arm. The first kinematic chain 4a has a plurality of joints 5a and the second kinematic chain 4b has a plurality of joints 5 b. The angular position of the

joints

5a and 5b is variable, so that the kinematic chain can be moved in the working space by means of the

joints

5a and 5b, respectively. In particular, the

joints

5a and 5b can be actuated with a controlled velocity and a controlled acceleration for the movement, wherein the

joints

5a and 5b have a maximum velocity and a maximum acceleration.

End effectors

6a, 6b are arranged on the free ends of the

kinematic chains

4a and 4b, respectively, wherein the

end effectors

6a and 6b are each designed as grippers for gripping the workpiece 3.

The

kinematic chains

4a and 4b are able to move in the workspace. The end effector 6a can be moved by means of a kinematic chain 4a from a starting point along a movement path s₁(t) moving to the end point. The end effector 6b can be moved by means of a kinematic chain 4b from a starting point along a movement path s₂(t) moving to the end point.

The manipulating device 1 comprises a control module for manipulating the

kinematic chains

4a and 4b in order to move the end-

effectors

6a and 6b about the path s₁(t) and s₂(t) advancing. In this case, the trajectory function q₁On the basis of a trajectory function q, in which the kinematic chain 4a is steered₂On the basis of which the kinematic chain 4b is operated. The trajectory function q₁And q is₂Are each a function of vector values having as many entries as the number of

joints

6a, 6b that the

kinematic chains

4a, 4b have, respectively. For example, the first kinematic chain 4a has three joints, the associated trajectory function q being associated therewith₁E.g. by q₁（φ₁、φ₂、φ₃) Is described in which phi₁、φ₂、φ₃Respectively, the angular position of a joint. Furthermore, it is possible that the trajectory function comprises an adjustment speed and an adjustment acceleration of the joint and can be described, for example, as

。

The manipulating device 1 comprises means for determining a minimum time trajectory q for the

kinematic chains

4a and 4b, respectively₁And q is₂The trajectory determination module of (1). The minimum time trajectories are the trajectory functions for generating the movements of the

kinematic chains

4a and 4b, respectively, which require the shortest time to implement the movements. To implement said minimum time trajectory q₁The kinematic chain 4a takes a time T₁. To implement said minimum time trajectory q₂The kinematic chain 4a requires a time T₂. The parameters parameterizing the minimum time trajectory are respectively the intrinsic time τ₁、τ₂Wherein said minimum time trajectory q₁For example, with

Is derived and said minimum time trajectory is q₂(τ₂) 。

The control device 1 comprises a reparameterization module, wherein the reparameterization module is based on a global time curve t_RThus for the minimum time trajectory q₁And q is₂The reparameterization is carried out such that the total movement of the

kinematic chains

4a and 4b is collision-free. The control module is designed in particular to control the

kinematic chains

4a and 4b on the basis of and/or by means of a reparameterized minimum time trajectory for carrying out a working movement. The control module uses the reparameterized minimum time trajectory as a trajectory function. In the following figures it is shown how the reparameterisation module reparameterises the minimum time trajectory such that the total motion is collision free.

FIG. 2 shows the time τ inherent₁And τ₂A distracted subspace 7. The subspace of the figure is an example of a subspace for the manipulating device 1 of fig. 1. Inherent time τ₁And τ₂In particular forming the basis for the orthogonal normalization of said subspaces 7. Intrinsic time τ of said kinematic chain 4a₁Forming an abscissa in which the intrinsic time τ of the kinematic chain 4b₂Forming the ordinate. The minimum time trajectory q is graphically represented below the abscissa₁（τ₁) Time profile of (2). The minimum time trajectory q is graphically represented on the left side of the ordinate₂（τ₂) Time profile of (2). Also, inThe time coordinate tau is given in the subspace_SAnd τ_EIn which the time coordinate τ is_SCorresponding to the inherent time of the start of the total movement, and the time coordinate τ_EThe inherent time corresponding to the end of the total movement.

Fig. 3 shows a diagram in which the subspace 7 of fig. 2 has been divided into an effective space 8 and a collision space 9 by means of a reparameterization module. To this end, the parameterization module includes a checking function c. The check function c as an argument has a minimum time trajectory q₁（τ₁) And q is₂（τ₂) And thus c (q)₁（τ₁），q₂（τ₂)). The checking function c is designed to check that the

kinematic chains

4a and 4b for a given minimum time path q₁（τ₁) And q is₂（τ₂) Whether there is a collision. For the case in which the test function determines for a given minimum time trajectory q₁（τ₁) And q is₂（τ₂) At a particular time (τ)₁、τ₂) In the absence of collisions, the associated point (τ) in the subspace 7 is determined₁、τ₂) Calculated as the effective space 8. For the case in which the test function determines for a given minimum time trajectory q₁（τ₁) And q is₂（τ₂) At a particular time (τ)₁、τ₂) If there is a collision, the associated point (τ) in the subspace 7 is determined₁、τ₂) Calculated as collision space 9. The reparameterizing module is designed to determine the time (τ) of all the time instants₁、τ₂) Such a check for collision and/or non-collision is carried out.

FIG. 4 shows the subspace 7 of FIG. 3 with a global time curve t determined by the reparameterization module_R. The global time curve t_RThe time coordinate of the start point is connected with the time coordinate of the end point. The global time curve t_RThe shortest connection between these two points is represented here, but with the following conditions: the global timeCurve t_ROnly in the active space 8 and not through the collision space 9. The global time curve t_RCan be measured at t_R=（τ_1,R、τ_2,R) Is shown as a parameterized curve.

FIG. 5 shows how the control module curves over a global time t_ROn the basis of which the

kinematics chains

4a, 4b are manipulated to perform a collision-free overall task. In this case, the minimum time trajectory q is used₁（τ₁) And q is₂（τ₂) The

kinematic chains

4a and 4a are manipulated in such a way that τ is manipulated only in a combined manner₁And τ₂For the combination (τ)₁τ₂）=t_R=（τ_1,R、τ_2,R）。

Claims

1. The operating device comprises: comprises a robot (2),

wherein the robot (2) has a plurality of kinematic chains (4 a, 4 b), wherein each of the kinematic chains (4 a, 4 b) is movable in a working space, wherein at least two of the working spaces have an overlap,

wherein each kinematic chain (4 a, 4 b) is designed to perform a working movement,

having a control module for actuating the kinematic chain (4 a, 4 b) for carrying out a total movement, wherein the total movement can be represented by a work movement of the kinematic chain (4 a, 4 b),

wherein the control module is designed to determine the trajectory function (q)₁、q₂) On the basis of which the kinematic chain is controlled for carrying out the work-doing movement,

characterized by a trajectory determination module and a re-parameterization module,

wherein the trajectory determination module is designed to determine a respective trajectory function (q) for each of the work movements of the kinematic chain (4 a, 4 b)₁、q₂) Minimum time trajectory (q)₁(τ₁)、q₂(τ₂)），

Wherein the reparameterization module is configured to determine the minimum time trajectory (q) based on the correlation₁(τ₁)、q₂(τ₂) Track function (q)₁、q₂) The reparameterization is performed such that the total motion is collision-free.

2. Handling device (1) according to claim 1, where said kinematic chains (4 a, 4 b) are each robot arms.

3. The handling device (1) according to claim 1 or 2, characterised in that said minimum time trajectory (q)₁(τ₁)、q₂(τ₂) Is a trajectory function (q)₁、q₂) The trajectory function requires the least time to perform the work motion.

4. The handling device (1) according to any one of the preceding claims, wherein said trajectory determination module is configured for determining said minimum time trajectory (q) on the basis of a limited maximum acceleration and/or a limited maximum speed₁(τ₁)、q₂(τ₂)）。

5. The handling device (1) according to any one of the preceding claims, wherein said reparameterization module is configured for using a global time curve t_RThe total motion is re-parameterized.

6. Handling device (1) according to any of the preceding claims, where said robot (2) has n kinematic chains (4 a, 4 b), where said global time curve t is_RIs a curve in n-dimensional space.

7. Handling device (1) according to any of the preceding claims, characterized in that said trajectory is passed throughThe determination module is respectively assisted by an inherent time (tau)₁、τ₂) To describe said minimum time trajectory (q)₁(τ₁)、q₂（τ₂) Wherein the reparameterisation module has a checking function (c (q)) for checking for collisions of the kinematic chain₁(τ₁)、q₂（τ₂) And the reparameterisation module is configured to determine the intrinsic time (τ)₁、τ₂) The spanned subspace (7) is divided into a collision space (9) and an effective space (8), wherein the collision space (9) is defined by points in the subspace (7) for which the check function c determines a collision of the kinematic chain (4 a, 4 b), and the effective space (8) is defined by points in the subspace (7) for which the check function determines a collision-free behavior of the kinematic chain (4 a, 4 b), wherein the reparameterization module is designed as a global time curve t_R-determining a curve in said effective space (8).

8. The handling device (7) according to claim 7, characterised in that the total movement starts at a start point and ends at an end point, wherein a time coordinate (τ s) can be assigned to the start point and a time coordinate (τ s) can be assigned to the end point in the subspace (7)_E) Wherein the reparameterization module is configured to determine the global time curve t as the shortest connection between the time coordinates of an end point and a start point in the active space (7)_R。

9. Manipulator (1) according to one of claims 6 to 8, wherein the total movement starts at a start point and ends at an end point, wherein a time coordinate (τ) can be assigned to the start point in the subspace (7)_S) And can assign a time coordinate (τ) to the end point_E) Wherein the reparameterization module is configured to act as a starting point sum in the effective space (7)Determining the global time curve t by the fastest connection between the time coordinates of the end points_R。

10. The handling device (1) according to any one of the preceding claims, wherein the control module is configured to scale a reparameterized minimum time trajectory (q) by means of an inverse kinematics mechanism for manipulating the robot (2)₁(τ₁)、q₂（τ₂））。

11. An operating device (1) according to any one of the preceding claims, characterised in that the total movement comprises asynchronous work movements of two kinematic chains (4 a, 4 b).

12. Method for operating a robot (2), in particular with a handling device according to any of the preceding claims, characterized in that a minimum time trajectory (q) is determined for each kinematic chain (4 a, 4 b) of the robot (2)₁、q₂) Wherein such pairs are based on the minimum time trajectory (q)₁(τ₁)、q₂（τ₂) Track function (q)₁、q₂) The parameterization is carried out such that the total movement of the kinematic chains (4 a, 4 b) is collision-free.

13. Computer program having program code sections for implementation, characterized in that the method according to claim 11 is implemented when the computer program is executed on a computer or on the operating device (1).