ROBOT SYSTEM, METHOD FOR CONTROLLING A ROBOT SYSTEM, AND PROCESSING SYSTEM

Abstract

The invention relates to a robot system, to a corresponding method, and to a processing system, wherein, along a process line, which is formed by guide rails, or on a conveyor belt, objects or workpieces are optionally moved or transported on carrier devices having gripping elements. The robot arm removes the objects from the process line by pulling or pushing the objects from a plane or surface of the process line into a working chamber compliantly, i.e., in a non-rigid manner by means of force control, wherein the objects are positioned and oriented in the working chamber by means of guiding elements. After the processing of the objects in the working chamber, the objects are pushed or pulled back onto the process line by means of the robot arm. The process line can comprise passive, non-driven rollers or the like instead of an actively driven conveyor belt, wherein the robot arm nudges or pushes the objects in order to transport the objects.

Claims

1. Robotic system having at least one robot arm and a control unit for controlling the movement of the robot arm, which has at least one effector, the robotic system being positionable and orientable in the region of a process line along which an object or a carrier device, on which the object is arranged, can be moved, the control unit and the robot arm being configured such that the robot arm can interact with the object in the region of a working space assigned to the robotic system such that the effector processes the object, and the robot arm can guide the object or the carrier device into and/or out of the working space by means of the effector; wherein the robotic system has a compliance control and the control unit is further configured such that the robot arm displaces the object or the carrier device relative to at least one guide means of the working space for guiding the object or the carrier device in such a way that the object or the carrier device is automatically positioned in the correct position relative to the robotic system for processing.

2. Robotic system according to claim 1, in which the working space is provided in the region of the process line and the control unit and the robot arm are configured such that the robot arm can guide the object or the carrier device along the process line between two mutually spaced guide means by means of the effector.

3. Robotic system according to claim 1, in which the working space is provided outside the process line and the control unit and the robot arm are configured such that the robot arm moves the object or the carrier device from the process line into the working space between two converging guide means and/or out of these guide means and thus back from the working space to the process line.

4. Robotic system according to claim 2, in which the control unit and the robot arm are configured such that the robot arm can apply a pull and/or push force to the object or to the carrier device by means of the effector.

5. Robotic system according to claim 1, in which the effector is configured such that it can cooperate with the object in the region of the working space without contact, forming a contact or changing the object.

6. Method for controlling a robotic system which has at least one robot arm and a control unit for controlling the movement of the robot arm, which has at least one effector, the robotic system having a compliance control and being positionable and orientable in the region of a process line, along which an object or a carrier device on which the object is arranged is movable, the robot arm interacting with the object in the region of a working space assigned to the robotic system, and the working space having at least one guide means for guiding the object or the carrier device, comprising the steps of: processing the object by means of the effector; and for the purpose of processing the object, guiding the object or the carrier device by means of the robot arm relative to the at least one guide means of the working space in such a way that the object or the carrier device is automatically positioned in the correct position to the robotic system for processing; and/or after the processing of the object has been completed, the object or the carrier device is guided out of the guide means and thus out of the working space by means of the robot arm.

7. Method according to claim 6, in which the guide means are provided in the region of the process line and are spaced from one another, the robot arm guiding the object or the carrier device between the guide means and thus along the process line.

8. Method according to claim 6, in which the robot arm guides the object or the carrier device from the process line between two mutually converging guide means and/or out of these guide means to the process line.

9. Method according to claim 6, in which the step of guiding comprises: touching the object or the carrier device without connection by means of the effector; and applying a pull and/or push force to the object or to the carrier device by means of the effector.

10. Method according to claim 6, in which the step of guiding comprises: captively gripping the object or the carrier device by means of the effector; and applying a pull and/or push force to the object or to the carrier device by means of the effector, or lifting the object or the carrier device by means of the effector, transferring it into a working position and setting down the object or the carrier device in this working position.

11. Method according to claim 6, in which the control unit and the robot arm are configured in such a way that clocking is predetermined by the robotic system when the object or the carrier device is guided.

12. Processing system comprising a process line along which objects or carrier devices for these objects are movable, and a robot arranged in the region of said process line, said robot having one or more axes and being formed with compliance control, wherein at least one guide means arranged in the region of the process line and adapted to transfer the object or the carrier device by a movement of the robot into a processing position provided for further processing of the object.

13. Processing system according to claim 12, in which the guide means is formed of spaced-apart guide surfaces for the object or the carrier devices.

14. Processing system according to claim 13, in which the guide surfaces are arranged along a process line which is of linear or non-linear construction.

15. Processing system according to claim 14, in which the guide surfaces are arranged with clearance to the object guided along the process line or the carrier device.

15. Processing system according to claim 13, in which the guide surfaces are arranged in a working space located in the region of the process line or adjacent to the process line.

16. Processing system according to claim 15, in which the working space and the process line are substantially on one plane.

17. Processing system according to claim 15, in which the working space and the process line are in different planes and the guide means is aligned transversely or inclined to the plane of the process line.

18. Processing system according to claim 16 in which the guide surfaces converge to each other towards the intended machining position.

19. Processing system according to claim 12, in which the guide means are flexibly designed.

20. Processing system according to claim 12, in which the robot is a mobile robot.

Description

[0075] Further advantages and characteristics of the invention result from the description of the embodiments as shown in the attached figures, in which

[0076] FIG. 1 exemplarily shows a perspective view of a robotic system at a known flow processing device;

[0077] FIG. 2 shows a perspective view of a processing system with a robotic system in a first embodiment according to the invention;

[0078] FIGS. 2a,b,c are examples of different positions of a robot arm of the robotic system in the processing system from FIG. 2;

[0079] FIG. 3 is a perspective view of a processing system with a robotic system in a second embodiment according to the invention;

[0080] FIGS. 3a,b show examples of different positions of a robot arm of the robotic system according to the invention in the processing system from FIG. 3;

[0081] FIG. 4a is a perspective view of a processing system with a robotic system in a third embodiment according to the invention;

[0082] FIG. 4b is an example of a view from above of a process line from FIG. 4a; and

[0083] FIG. 5 is a perspective view of a processing system with a robotic system in a fourth embodiment according to the invention.

[0084] FIG. 1 shows an example of a state-of-the-art arrangement in which a robotic system 1, preferably of the lightweight design, is positioned on a process line 2 of a flow or non-interrupted processing device 3. Along process line 2, workpieces or objects 4, which are arranged on corresponding carrier devices 5, are moved past the robotic system 1 via an active conveyor belt 6.

[0085] The robotic system 1 has a multi-axis robot arm 7, which at its end carries an effector 8, e.g. a measuring pin, by means of which the robot arm 7 interacts in the area of a working space 9 assigned to robot arm 7, which is located directly in front of robotic system 1 on process line 2. Using the measuring pin 8, the robot arm 7 can scan object 4 for testing purposes, for example.

[0086] In this arrangement, object 4 is automatically moved past robotic system 1 by the actively driven conveyor belt 6. Since the conveyor belt 6 moves at a given speed, the cycle of the work processes for the robotic system 1 is ultimately determined by the speed of the conveyor belt 6. Accordingly, the movements of the robot arm 7 must be adjusted to the speed of the conveyor belt 6, while the time window for the machining steps to be carried out by the robot arm 7 remains limited.

[0087] FIG. 2, on the other hand, shows a machining/processing/working system in a first embodiment according to the invention, in which the robotic system 1 can set the cycle or clocking/timing itself.

[0088] Various objects 10, 11 are placed on corresponding carrier devices 12, which have a frame or handle 13 on the side.

[0089] Process line 19 is formed by two guide means in the form of guide surfaces 20 arranged at an equal distance from each other, between which the carrier devices 12 are movable along. The guide surfaces 20 serve as guide rails, so to speak, between which the carrier devices 12 are pulled or pushed along by the robot arm 7 engaging the handle 12 of the carrier device 12.

[0090] FIGS. 2a to c do show schematically in plan view different position states of the robotic system 1, preferably a mobile robot with a seven-axis robot arm or manipulator 7.

[0091] In FIG. 2a it is shown how the robot arm 7 with its effector 8 on process line 19 acts on a handle 13 of the carrier device 12 to the left of the nominal working space 9 in order to pull it into the nominal working space 9.

[0092] After the object on the carrier device 12 has been processed, which is not shown here, the effector 8 engages the handle 13 of the carrier device 12 again and pushes it further to the right on process line 2, as FIGS. 2b and 2c indicate. The robot arm 7 can then move back to the left again in order to come into contact with a next carrier device 12 and to pull it back into the area of the nominal working space 9 for machining and working purposes.

[0093] Because the robot arm 7 automatically pulls the carrier device along process line 2 into the nominal working space 9, which is arranged directly in front of the robotic system 1 in this case, and then automatically pushes the carrier device 12 out of the nominal working space 9 after processing, the cycle of the work steps to be performed by robotic system 1 is set automatically or the robotic system 1 determines the feed rate on process line 19 depending on the work steps to be performed.

[0094] Due to the resulting increased variability in the process steps, different objects 10 and 11 can be processed individually and, if necessary, differently with one and the same robotic system 1 within one and the same processing system and transported individually along process line 19.

[0095] Since, according to the invention the robot or robotic system 1 comprises a compliance control, the robot arm 7 only has to apply a pull or push force acting along process line 19 when the effector 8 engages with handle 13. In this case, the linear guidance of the carrier devices 12 is carried out exclusively by the two guide surfaces 20. This guidance function in interaction with the force to be applied by the robot arm 7 makes it perfectly sufficient that the effector 8 simply comes to rest on the side of handle 13.

[0096] Due to the fact that, in the absence of the need for position control and regulation for robotic system 1, it does not have to occupy a fixed, unchangeable position in space and in relation to process line 19, according to the invention the robotic system 1 can be easily positioned via a mobile platform 21 at an intended position relative to the nominal working space 9 and relative to process line 19. The position of robotic system 1 can therefore be adapted to altered machining processes without complicated retooling measures. Furthermore, it is possible that in such a processing system several such robotic systems 1 work together independently or synergistically on a process line 19, possibly even with the interposition of one or more workers. This allows any sequences to be designed for a machining system, e.g. specifically setting up production lines with HRC robotic systems. There are virtually no limits to the variability in the design and configuration of such processing systems according to the invention.

[0097] While FIG. 2 shows a processing system with an exclusively linear process line 19, FIG. 4a shows a processing system in a third embodiment according to the invention with a process line 22 that changes in the course. This process line 22 is also formed by two spaced guide rails or surfaces 23 within which objects 24 can be pushed along by the robot arm 7. Since robot arm 7 with its compliance control merely provides the feed for objects 24 by the effector 8 coming into contact with it laterally, it is possible that objects 24 can be guided around a curve 25 of process line 22 in interaction with the guide surfaces 23.

[0098] To prevent blocking, a certain clearance S is provided between the guide surfaces 23 and the dimensions of the objects 24, as shown in FIG. 4b. Robotic system 1 is therefore able to move objects 24 along process line 22 with a certain amount of vagueness across the direction of movement due to its control behaviour.

[0099] FIG. 3 shows another processing system in a second embodiment of the invention.

[0100] Along a process line 26, here again an active conveyor belt 6, carrier devices 14 move, on which the objects 15 to be processed are located. The carrier devices 14 comprise a handle element 16 on the front side.

[0101] Directly in front of the robotic system 1 is the nominal working space 17, which is limited by two guide means 18, which converge towards each other.

[0102] As can be seen schematically in FIGS. 3a and b, the robot arm 7 of the robotic system 1 according to the invention fetches the carrier device 14 from the conveyor belt 6 and pulls it into the working space 17 in front of it, whereby the converging guide means 18 automatically centers the carrier device 14 into a final working position, in that the carrier device 14 engages in the stops 18 of the guide means 18 so that the robot arm 7 can then carry out the desired working steps without having to position the carrier device 14 with high precision, which facilitates its parameterization in advance.

[0103] After finishing the processing of objects 15, the robot arm 7 can push the carrier device 14 back onto the conveyor belt 6 by its effector 8 simply engaging the handle element 16.

[0104] The compliance control of the robot used according to the invention also allows the robotic system 1 to move the carrier devices 14 back and forth between the conveyor 6 and the working space 17, although the conveyor 6 and the working space 17 are not on a common plane.

[0105] FIG. 5 schematically shows a processing system in a fourth embodiment according to the invention. In it there is a nominal working space 27 further away from a conveyor belt 6, on which objects 24 move along. The effector of robotic system 1 is designed as a gripping mechanism 28, which can grip the objects 24. The robot arm 7 lifts the objects 24 and transfers them to the working space 27 by a rotary movement, illustrated by several positions of the robot arm 7. The working space 27 has a guide means in the form of a tapering funnel or hopper 29, into which the robot arm 7 inserts the object 24. The object 24 is then automatically centered in the final working or assembly position through the tapered walls of the hopper 29 as soon as the object 24 has been completely removed from the robot arm 7.

[0106] According to the invention, guidance along predetermined guide means, regardless of their design, is made possible by the fact that the robotic system, according to the invention, is inherently compliant with regard to the motor function or kinematics, which is further supported by the possibility, for example, of force, compliance or impedance control, or by a hybrid approach as a result of a combination of such different controls, of drive units in the individual joints between the links of the robot arm. This can take many forms. The most important are a control in joint coordinates, i.e. a coordinated axis control, or a task-oriented control, which is defined, for example, in Cartesian space, and are translated via geometric projections, such as, for example, by the Jacobi matrix, nominal joint torques or nominal joint forces. In addition, extensions such as multi-priority control could be used.

[0107] In interaction with specified guide means in the area of process lines, simple guidance of the objects by the robot can thus be realized.

[0108] The robotic system 1 according to the invention is also particularly suitable in environments in which people are simultaneously involved in the working processes of a flow processing device with this robotic system 1, so that such robotic systems 1 can be designed for a corresponding human-robot collaboration.

[0109] It becomes clear that the fact that, according to the invention, robotic system 1, which in itself goes beyond pure pick and place work steps and repetitive assembly steps, is intended to actively process objects, independently determines the timing of the individual work steps within a flow processing device, no limits are set to variability and flexibility, both with regard to the type of objects to be processed and the type of processing steps to be carried out on these objects.

[0110] The robotic system 1 according to the invention can be used individually for the respective intended purposes and programmed and parameterised accordingly, whereby the programming effort is lower, depending on the compliant design of the robotic system 1 as such. In particular, the aforementioned compliance control and force control with respect to the individual joints of the robot arm and thus of the robotic system 1 according to the invention with respect to its overall behavior can be used for this purpose.