DE102019102470A1 - Teach-in process for a robot system consisting of two robot manipulators - Google Patents

Abstract

The invention relates to a method for teaching in desired holding parameters when transporting a load (30) by a first robot manipulator (10) together with a second robot manipulator (20), comprising the steps: Positioning (S1) a first end effector (11) of the first Robot manipulator (10) at a first desired position of the load (30) by manually guiding the first robot manipulator (10), - Positioning (S2) a second end effector (21) of the second robot manipulator (20) at a second desired position of the load (30) ) by manually guiding the second robot manipulator (20) so that the load (30) is contacted by the first end effector (11) and the second end effector (21) opposite, - fixing (S3) the first robot manipulator (10) in its current pose Control of drives of the first robot manipulator, - Manual pressing (S4) of the second end effector (21) against the load (30), - Detection (S5) of a du The force and / or a moment caused by the manual pressure and transmitted by the second end effector (21) via the load (30) and acting on the first end effector (11), - storage (S6) of the detected force and / or the detected moment as the desired holding force of the first end effector (11) and the second end effector (21) against the load (30) and storing the first desired position and the second desired position as the respective desired holding position in a control program, and force-regulated or impedance-regulated holding (S7 ) the load (30) through the first robot manipulator (10) and through the second robot manipulator (20) with the desired holding force.

Description

The invention relates to a method for teaching in desired holding parameters when transporting a load by a first robot manipulator together with a second robot manipulator, and a robot system for teaching in desired holding parameters when transporting a load.

The object of the invention is to set up two robot manipulators in such a way that they take up a load together with predetermined holding parameters, such as holding force or holding positions of the end effectors.

The invention results from the features of the independent claims. Advantageous further developments and refinements are the subject of the dependent claims.

• - Positionieren eines ersten Endeffektors des ersten Robotermanipulators an einer ersten gewünschten Position der Last durch manuelles Führen des ersten Robotermanipulators,
• - Positionieren eines zweiten Endeffektors des zweiten Robotermanipulators an einer zweiten gewünschten Position der Last durch manuelles Führen des zweiten Robotermanipulators, sodass die Last vom ersten Endeffektor und vom zweiten Endeffektor gegenüberliegend kontaktiert wird,
• - Fixieren des ersten Robotermanipulators in seiner gegenwärtigen Pose durch Ansteuerung von Antrieben des ersten Robotermanipulators,
• - Manuelles Andrücken des zweiten Endeffektors gegen die Last,
• - Erfassen einer durch das manuelle Andrücken verursachten und von dem zweiten Endeffektor über die Last übertragenen und auf den ersten Endeffektor wirkenden Kraft und/oder eines Moments,
• - Abspeichern der erfassten Kraft und/oder des erfassten Moments als gewünschte Haltekraft des ersten Endeffektors und des zweiten Endeffektors gegen die Last und Abspeichern der ersten gewünschten Position und der zweiten gewünschten Position als jeweilige gewünschte Halteposition jeweils in einem Steuerprogramm, und
• - Kraftgeregeltes oder impedanzgeregeltes Halten der Last durch den ersten Robotermanipulator und durch den zweiten Robotermanipulator mit der gewünschten Haltekraft.

A first aspect of the invention relates to a method for teaching in desired holding parameters when transporting a load through a first robot manipulator together with a second robot manipulator, comprising the steps:

• Positioning a first end effector of the first robot manipulator at a first desired position of the load by manually guiding the first robot manipulator,
• Positioning a second end effector of the second robot manipulator at a second desired position of the load by manually guiding the second robot manipulator so that the load is contacted by the first end effector and the second end effector opposite one another,
• Fixation of the first robot manipulator in its current pose by actuating drives of the first robot manipulator,
• - manual pressing of the second end effector against the load,
• Detecting a force and / or a moment caused by the manual pressing and transmitted by the second end effector via the load and acting on the first end effector,
• - Saving the detected force and / or the detected torque as the desired holding force of the first end effector and the second end effector against the load and storing the first desired position and the second desired position as the respective desired holding position in each case in a control program, and
• - Force-controlled or impedance-controlled holding of the load by the first robot manipulator and by the second robot manipulator with the desired holding force.

When the load is held in a force-controlled manner, the drives of the first robot manipulator and of the second robot manipulator are controlled in such a way that a predetermined force acts on the loads from the respective end effector of the respective robot manipulator. A similar result is provided by an impedance-controlled control of the respective robot manipulator, in which a virtual spring with a predetermined stiffness is generated, the zero position of the spring advantageously being within the volume of the load, so that the distance between the respective end effector and the respective zero position and by multiplication thereof Distance with the specified spring stiffness results in a certain force from the respective end effector on the loads.

The manual pressing of the second end effector against the load advantageously takes place while the load is raised from the ground, so that advantageously no frictional forces are transmitted from the ground to the load. However, as soon as the load is held by the two robot manipulators, the necessary steps of the first aspect of the invention can be repeated, so that in particular the force of the second end effector against the load is readjusted by manual pressing and is advantageously confirmed on an input unit.

When the respective robot manipulator is guided manually, the respective robot manipulator is advantageously controlled in a gravity-compensated manner; H. that the links of the respective robot manipulator are freely movable around their respective joints, only the drives on the joints of the respective robot manipulator being controlled in such a way that the weight of the individual links is compensated for, so that gravity does not accelerate the links or the end effector of the respective robot manipulator caused.

A pose of the respective robot manipulator here includes, in particular, information about joint angles of joints that connect the respective members of the respective robot manipulator to one another. Cartesian position coordinates, in particular of the end effector, can also be used, but the angle and / or position information of the individual members is also advantageously included in the pose, in particular in the case of a redundant robot manipulator (i.e. a robot manipulator with at least two joints with degrees of freedom that are redundant to one another).

While the first robot manipulator is fixed in its current pose, ie the pose that it has at the time the second end effector of the second robot manipulator is positioned, the first robot manipulator is used as an immovable force sensor. Fixing advantageously prevents the manual pressing of the second end effector against the load from accelerating the first robot manipulator. This is done in particular by correspondingly controlling the drives of the first robot manipulator. In response to a control signal, the drives generate a force or a moment, which is selected accordingly, so that the forces and / or moments of the drives compensate for all external disturbances on the first robot manipulator. In particular, a corresponding regulation is implemented for this purpose, which regulates external influences and disturbances on the first robot manipulator within the respectively possible range, but preferably asymptotically stable.

The detection of the force and / or the torque caused by the manual pressing and transmitted from the second end effector via the load and acting on the first end effector is advantageously carried out by means of torque sensors, which are preferably arranged in the joints of the first robot manipulator, or alternatively or also additionally by means of strain gauges, which are advantageously arranged in the joints or on the limbs of the first robot manipulator.

It is an advantageous effect of the invention that one or more control units can be set up and parameterized by one or more robot manipulators in a short and simple process, so that a load of two individual robot manipulators can be held with a predetermined holding force. Once this force has been determined, the load can advantageously be moved by the two robot manipulators, for example in order to be transported from one location to another. Furthermore, by means of the method according to the invention, two individual robot manipulators, which are in principle independent of one another, can be configured such that they hold a load synchronously and cooperatively and, under certain circumstances, also transport them. In this case, a hierarchy between the control unit of the first robot manipulator and the control unit of the second robot manipulator is advantageously defined, so that a control unit of the two robot manipulators can command both robot manipulators.

According to an advantageous embodiment, the method further comprises the step of: determining a distance between the first desired position and the second desired position and storing the distance.

The distance between the first desired position and the second desired position can advantageously be compared with a predefined control distance or compared with a limit value, so that when the load slips off the first end effector and the second end effector, particularly in the case of force-controlled robot manipulators, this can be prevented both end effectors pick up speed and accelerate towards each other. A squeeze of a soft load can also be advantageously checked in this way.

• - Konfigurieren des Steuerprogramms derart, dass der gespeicherte Abstand beim Transportieren der Last abzüglich eines vordefinierten Versatzes eingehalten wird.

According to a further advantageous embodiment, the method further comprises the step:

• - Configure the control program in such a way that the stored distance is maintained when transporting the load minus a predefined offset.

If the distance minus a predefined offset is maintained, this particularly advantageously prevents the above-mentioned situations, namely that a soft load is compressed too much by the force-controlled robot manipulators, or that when the load is dropped, both end effectors move towards one another indefinitely.

According to a further advantageous embodiment, the first robot manipulator is fixed on the basis of a detected current position of the first robot manipulator, the first robot manipulator being held at its current position in a position-controlled manner by actuating the drives of the first robot manipulator.

According to a further advantageous embodiment, when the first robot manipulator is fixed, the first robot manipulator is controlled in an impedance-controlled manner.

If the first robot manipulator is controlled in an impedance-controlled manner, the above-mentioned artificial stiffness of the control is advantageously chosen to be as high as possible, so that the resistance of the first robot manipulator to an external movement is as high as possible.

According to a further advantageous embodiment, a stiffness of the impedance-controlled first robot manipulator has the greatest possible value of the first robot manipulator.

The greatest possible value of the first robot manipulator is in particular a numerical one Value that is technically adjustable on the first robot manipulator.

According to a further advantageous embodiment, the detection of the detected force and / or the detected torque as the desired holding force of the first end effector and the second end effector against the load and / or the storage of the first desired position and the second desired position as the respective desired holding position after one Detection of an input signal entered by a user.

According to a further advantageous embodiment, the positioning of the first end effector at the first desired position of the load takes place in a first desired orientation of the first end effector and the positioning of the second end effector at the second desired position of the load in a second desired orientation of the second end effector, wherein the The method further comprises the step of: storing the first desired orientation and the second desired orientation as the respective desired holding orientation in each case in the control program.

According to a further advantageous embodiment, the force and / or moments caused by the manual pressing and transmitted from the second end effector via the load and acting on the first end effector are detected by torque sensors arranged in the first robot manipulator.

According to a further advantageous embodiment, the torque sensors are arranged on the joints of the first robot manipulator. The torque sensors are advantageously arranged on a drive in a respective joint of the respective robot manipulator.

Another aspect of the invention relates to a robot system for teaching in desired holding parameters when transporting a load, comprising a first robot manipulator with a first control unit and with a first position detection unit and comprising a second robot manipulator with a second control unit and with a second position detection unit, the first position detection unit is designed to detect a current pose of the first robot manipulator after manually guiding the first robot manipulator to a first desired position of the first end effector on the load, and wherein the second position detection unit is designed to detect a current pose of the second robot manipulator after manual guiding of the second robot manipulator to a second desired position of the second end effector on the load, wherein the first control unit is designed to drive the first robot manipulator gate to fix in its current pose and after manually pressing the second end effector against the load by manually guiding the second robot manipulator, a force transmitted through the load to the first end effector as the desired holding force of the first end effector and the second end effector against the load , wherein the robot system further comprises a storage unit, the storage unit being designed to store the detected force as the desired holding force and to store the first desired position and the second desired position as the respective desired holding positions in a control program, and wherein the first control unit and / or the second control unit is designed to control the first robot manipulator and the second robot manipulator by holding the load in a force-controlled or impedance-controlled manner with the desired holding force.

Advantages and preferred developments of the proposed robot system result from an analog and analogous transmission of the statements made above in connection with the proposed method.

Further advantages, features and details result from the following description, in which - if necessary with reference to the drawing - at least one exemplary embodiment is described in detail. Identical, similar and / or functionally identical parts are provided with the same reference symbols.

• 1 ein Verfahren zum Einlernen von gewünschten Halteparametern beim Transportieren einer Last durch einen ersten Robotermanipulator zusammen mit einem zweiten Robotermanipulator gemäß einem Ausführungsbeispiel der Erfindung, und
• 2 ein Robotersystem zum Einlernen von gewünschten Halteparametern beim Transportieren einer Last gemäß einem weiteren Ausführungsbeispiel der Erfindung.

Show it:

• 1 a method for teaching in desired holding parameters when transporting a load through a first robot manipulator together with a second robot manipulator according to an embodiment of the invention, and
• 2nd a robot system for teaching in desired holding parameters when transporting a load according to a further embodiment of the invention.

The representations in the figures are schematic and not to scale.

• - Positionieren S1 eines ersten Endeffektors 11 des ersten Robotermanipulators 10 an einer ersten gewünschten Position der Last 30 durch manuelles Führen des ersten Robotermanipulators 10,
• - Positionieren S2 eines zweiten Endeffektors 21 des zweiten Robotermanipulators 20 an einer zweiten gewünschten Position der Last 30 durch manuelles Führen des zweiten Robotermanipulators 20, sodass die Last 30 vom ersten Endeffektor 11 und vom zweiten Endeffektor 21 gegenüberliegend kontaktiert wird,
• - Fixieren S3 des ersten Robotermanipulators 10 in seiner gegenwärtigen Pose durch Ansteuerung von Antrieben des ersten Robotermanipulators, wobei beim Fixieren des ersten Robotermanipulators 10 der erste Robotermanipulator 10 impedanzgeregelt ist und eine Steifigkeit des impedanzgeregelten ersten Robotermanipulators 10 einen größtmöglichen Wert des ersten Robotermanipulators 10 aufweist,
• - Manuelles Andrücken S4 des zweiten Endeffektors 21 gegen die Last 30,
• - Erfassen S5 einer durch das manuelle Andrücken verursachten und von dem zweiten Endeffektor 21 über die Last 30 übertragenen und auf den ersten Endeffektor 11 wirkenden Kraft,
• - Abspeichern S6 der erfassten Kraft als gewünschte Haltekraft des ersten Endeffektors 11 und des zweiten Endeffektors 21 gegen die Last 30 und Abspeichern der ersten gewünschten Position und der zweiten gewünschten Position als jeweilige gewünschte Halteposition jeweils in einem Steuerprogramm, und
• - Kraftgeregeltes oder impedanzgeregeltes Halten S7 der Last 30 durch den ersten Robotermanipulator 10 und durch den zweiten Robotermanipulator 20 mit der gewünschten Haltekraft.
• - Ermitteln S8 eines Abstandes zwischen der ersten gewünschten Position und der zweiten gewünschten Position und Abspeichern des Abstandes.
• - Konfigurieren S9 des Steuerprogramms derart, dass der gespeicherte Abstand beim Transportieren der Last 30 abzüglich eines vordefinierten Versatzes eingehalten wird.

1 shows a method for teaching in desired holding parameters when transporting a load 30th by a first robot manipulator 10th together with a second robot manipulator 20 , comprising the steps:

• - Positioning S1 of a first end effector 11 of the first robot manipulator 10th at a first desired position of the load 30th by manually guiding the first robot manipulator 10th ,
• - positioning S2 of a second end effector 21 of the second robot manipulator 20 at a second desired position of the load 30th by manually guiding the second robot manipulator 20 so the load 30th from the first end effector 11 and the second end effector 21 is contacted opposite,
• - Fix S3 of the first robot manipulator 10th in its current pose by controlling drives of the first robot manipulator, while fixing the first robot manipulator 10th the first robot manipulator 10th is impedance-controlled and a stiffness of the impedance-controlled first robot manipulator 10th a maximum value of the first robot manipulator 10th having,
• - Manual pressing S4 of the second end effector 21 against the load 30th ,
• - Capture S5 one caused by manual pressing and by the second end effector 21 about the load 30th transferred and to the first end effector 11 acting force,
• - Save S6 the detected force as the desired holding force of the first end effector 11 and the second end effector 21 against the load 30th and storing the first desired position and the second desired position as the respective desired holding position in a control program, and
• - Force-controlled or impedance-controlled holding S7 the burden 30th through the first robot manipulator 10th and by the second robot manipulator 20 with the desired holding force.
• - Determine S8 a distance between the first desired position and the second desired position and storing the distance.
• - Configure S9 the control program such that the stored distance when transporting the load 30th minus a predefined offset.

2nd shows a robot system 1 for teaching in the desired stopping parameters when transporting a load 30th , having a first robot manipulator 10th with a first control unit 12th and with a first position detection unit 13 and having a second robot manipulator 20 with a second control unit 22 and with a second position detection unit 23 , wherein the first position detection unit 13 is executed, a current pose of the first robot manipulator 10th after manually guiding the first robot manipulator 10th to a first desired position of the first end effector 11 at the load 30th to detect, and wherein the second position detection unit 23 is executed, a current pose of the second robot manipulator 20 after manually guiding the second robot manipulator 20 a second desired position of the second end effector 21 at the load 30th to capture, the first control unit 12th is designed to drive the first robot manipulator 10th to fix in his current pose and after manually pressing the second end effector 21 against the load 30th by manually guiding the second robot manipulator 20 one about the load 30th to the first end effector 11 transferred force as the desired holding force of the first end effector 11 and the second end effector 21 against the load 30th to capture, capturing the so on the first end effector 11 acting force in the first robot manipulator 10th arranged torque sensors 15 he follows. The torque sensors 15 are on joints, especially on the drives with the first position detection unit 13 of the first robot manipulator 10th arranged. The robot system 1 also has a storage unit 14 which stores the detected force as the desired holding force and stores the first desired position and the second desired position as the respective desired holding positions in a control program. The first control unit 12th and the second control unit 22 are each designed to be the first robot manipulator 10th and the second robot manipulator 20 by force-controlled or impedance-controlled holding of the load 30th to be controlled with the desired holding force.

Although the invention has been illustrated and explained in more detail by means of preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that there are a variety of possible variations. It is also clear that exemplary embodiments really only represent examples that are not to be interpreted in any way as a limitation of the scope, the possible applications or the configuration of the invention. Rather, the preceding description and the description of the figures enable the person skilled in the art to specifically implement the exemplary embodiments, the person skilled in the art being able to make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, with knowledge of the disclosed inventive concept, without departing from the scope defined by the claims and their legal equivalents, such as further explanations in the description.

Reference list

1

Robot system

10th

first robot manipulator

11

first end effector

12th

first control unit

13

first position detection unit

14

Storage unit

15

Torque sensors

20

second robot manipulator

21

second end effector

22

second control unit

23

second position detection unit

30th

load

S1

Positioning

S2

Positioning

S3

Fix

S4

Manual pressing

S5

Capture

S6

Save

S7

Hold

S8

Determine

S9

Configure

Claims (10)

Method for teaching in desired holding parameters when transporting a load (30) through a first robot manipulator (10) together with a second robot manipulator (20), comprising the steps: - positioning (S1) a first end effector (11) of the first robot manipulator (10) at a first desired position of the load (30) by manually guiding the first robot manipulator (10), - Positioning (S2) a second end effector (21) of the second robot manipulator (20) at a second desired position of the load (30) by manually guiding the second robot manipulator (20) so that the load (30) from the first end effector (11) and is contacted by the second end effector (21), - Fixing (S3) the first robot manipulator (10) in its current pose by controlling drives of the first robot manipulator, - Manual pressing (S4) of the second end effector (21) against the load (30), Detecting (S5) a force and / or a moment caused by the manual pressing and transmitted by the second end effector (21) via the load (30) and acting on the first end effector (11), - Saving (S6) the detected force and / or the detected torque as the desired holding force of the first end effector (11) and the second end effector (21) against the load (30) and storing the first desired position and the second desired position as the respective desired Stop position each in a control program, and - Force-controlled or impedance-controlled holding (S7) of the load (30) by the first robot manipulator (10) and by the second robot manipulator (20) with the desired holding force. Procedure according to Claim 1 , further comprising the step: - determining (S8) a distance between the first desired position and the second desired position and storing the distance. Procedure according to Claim 2 , further comprising the step: - Configuring (S9) the control program in such a way that the stored distance is maintained when transporting the load (30) minus a predefined offset. Procedure according to one of the Claims 1 to 3rd The first robot manipulator (10) is fixed on the basis of a detected current position of the first robot manipulator (10), and the first robot manipulator (10) is held at its current position in a position-controlled manner by actuating the drives of the first robot manipulator. Procedure according to one of the Claims 1 to 3rd , the first robot manipulator (10) being impedance-controlled when the first robot manipulator (10) is fixed. Procedure according to Claim 5 The rigidity of the impedance-controlled first robot manipulator (10) has the greatest possible value of the first robot manipulator (10). Method according to one of the preceding claims, wherein the positioning of the first end effector (11) at the first desired position of the load (30) takes place in a first desired orientation of the first end effector (11) and the positioning of the second end effector (21) on the second desired position of the load (30) in a second desired orientation of the second end effector (21), further comprising the step: Saving (S6A) the first desired orientation and the second desired orientation as the respective desired stop orientation in each case in the control program. Method according to one of the preceding claims, wherein the detection of a force and / or the torque caused by the manual pressing and transmitted from the second end effector (21) via the load (30) and acting on the first end effector (11) in the first robot manipulator (10) arranged torque sensors (15). Method according to one of the preceding claims, wherein the torque sensors (15) are arranged on joints of the first robot manipulator (10). Robot system (1) for teaching in desired holding parameters when transporting a load (30), comprising a first robot manipulator (10) with a first control unit (12) and with a first position detection unit (13) and having a second robot manipulator (20) with a second Control unit (22) and having a second position detection unit (23), the first position detection unit (13) being designed to carry out a current pose of the first robot manipulator (10) after manually guiding the first robot manipulator (10) to a first desired position of the first End effector (11) on the load (30), and wherein the second position detection unit (23) is designed to a current pose of the second robot manipulator (20) after manually guiding the second robot manipulator (20) a second desired position of the second End effector (21) to detect the load (30), the first control unit (12) being used for this purpose It is necessary to control drives of the first robot manipulator (10) for fixing in its current pose and after manually pressing the second end effector (21) against the load (30) by manually guiding the second robot manipulator (20) one over the load (30). force and / or a moment transmitted to the first end effector (11) as the desired holding force of the first end effector (11) and the second end effector (21) against the load (30), the robot system (1) further comprising a storage unit (14 ), the storage unit (14) being designed to store the detected force and / or the detected moment as the desired holding force and to store the first desired position and the second desired position as the respective desired holding positions in a control program, and wherein the first control unit (12) and / or the second control unit (22) is designed for this, the first robot manipulator (10) and the second robot manipulator or (20) by force-controlled or impedance-controlled holding of the load (30) with the desired holding force.

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