Absolute Robot-Assisted Positioning Method

Abstract

An absolute robot-assisted positioning method is provided which can be performed by a facility. The method optimises an assembly task which has been created theoretically at a computer workstation and which is implemented in reality by the facility. The disclosed facility includes at least one robot, at least one measurement system and a computer, wherein the at least one measurement system monitors the at least one robot while the assembly task is being performed, and the robot and the measurement system are connected to each other via the computer.

Claims

1. A facility for performing an absolute robot-assisted positioning method for optimising an actual assembly task which is defined by theoretically defined steps, wherein the facility comprises: a. at least one robot which performs the assembly task; b. at least one measurement system which monitors the parameters of the robot; and c. at least one computer; d. wherein the computer comprises at least a memory unit, a computational unit, a transmission interface and a communications interface and is designed to: store a program which describes the theoretically defined assembly task, derive mutually adjusted processing steps for the exact said robot from the program by means of the computational unit using a predetermined algorithm, transmit the program to the robot via the transmission interface, monitor the robot, the measurement system and the sensors via the communications interface in order to execute the assembly task, receive measurement data of the measurement system via the communications interface and store them for documentation purposes, and compare said received measurement data with the predetermined data and, if there are any deviations above a predetermined threshold value, decide whether to discontinue or halt the assembly task immediately or at a later time.

2. The facility according to claim 1, wherein the computer is also designed to determine new nominal values for the program/subroutines from the detected deviations and to integrate them into the program/subroutines.

3. The facility according to claim 1, wherein the computer separately stores the data for each derived processing step of the program/subroutines, such that it is possible to subsequently reconstruct when and how a processing step in the program/subroutine has been modified.

4. The facility according to claim 1, wherein when creating the program, virtual operatives are defined at particular points which are critical to the method, such that the computational unit can specifically compare these operatives with the results of the measurement system.

5. The facility according to claim 1, wherein the operatives are expedients for fulfilling one or more of the tasks, in particular synchronisation tasks, of calibrating, regulating, monitoring and process control, documentation, status management and configuration.

6. The facility according to claim 1, wherein in order to monitor the robot movements, one or more measurement systems are implemented in the facility which take measurements by means of rotary theodolites or indoor GPS, a multitude of cameras for observing markers, laser trackers with or without orientation receivers, laser radar or other measuring method.

7. The facility according to claim 1, wherein the robot comprises one or more interfaces, and changes to the robot movements can be made by means of the computer via the interfaces.

8. The facility according to claim 1, wherein the program is created by means of textual and/or CAD-assisted programming and can be modified even while the facility is in operation, without thereby altering the theoretical definition of the assembly task.

9. The facility according to claim 1, wherein the facility is initialised for the first time automatically by means of the computer.

10. The facility according to claim 1, wherein the robot and the at least one measurement system form a network of individual systems which communicate with each other.

11. A facility for performing an absolute robot-assisted positioning method for optimising an actual assembly task which is defined by theoretically defined steps, wherein the facility comprises: a. at least two robots collaborating with each other, which perform the assembly task; b. at least one measurement system which monitors the parameters of the robots; and c. at least one computer; d. wherein the computer comprises at least a memory unit, a computational unit, a transmission interface and a communications interface and is designed to: store a program which describes the theoretically defined assembly task, derive subroutines from the program by means of the computational unit using a predetermined algorithm, wherein each subroutine relates to mutually adjusted processing steps for exactly one of the robots, transmit the subroutines to the robots via the transmission interface, monitor the robots, the measurement system and the sensors via the communications interface in order to execute the assembly task, optionally receive measurement data of the measurement system via the communications interface and store them for documentation purposes, and compare said received measurement data with the predetermined data in the subroutines and, if there are any deviations above a predetermined threshold value, decide whether to discontinue or halt the assembly task immediately or at a later time.

12. The facility according to claim 11, wherein the computer is also designed to determine new nominal values for the program/subroutines from the detected deviations and to integrate them into the program/subroutines.

13. The facility according to claim 11, wherein the computer separately stores the data for each derived processing step of the program/subroutines, such that it is possible to subsequently reconstruct when and how a processing step in the program/subroutine has been modified.

14. The facility according to claim 11, wherein when creating the program, virtual operatives are defined at particular points which are critical to the method, such that the computational unit can specifically compare these operatives with the results of the measurement system.

15. The facility according to claim 11, wherein the operatives are expedients for fulfilling one or more of the tasks, in particular synchronisation tasks, of calibrating, regulating, monitoring and process control, documentation, status management and configuration.

16. The facility according to claim 11, wherein in order to monitor the robot movements, one or more measurement systems are implemented in the facility which take measurements by means of rotary theodolites or indoor GPS, a multitude of cameras for observing markers, laser trackers with or without orientation receivers, laser radar or other measuring method.

17. The facility according to claim 11, wherein the robots comprise one or more interfaces, and changes to the robot movements can be made by means of the computer via the interfaces.

18. The facility according to claim 11, wherein the program is created by means of textual and/or CAD-assisted programming and can be modified even while the facility is in operation, without thereby altering the theoretical definition of the assembly task.

19. The facility according to claim 11, wherein the facility is initialised for the first time automatically by means of the computer.

20. The facility according to claim 11, wherein the at least two robots and the at least one measurement system form a network of individual systems which communicate with each other.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0054] Example embodiments of the invention will now be described on the basis of figures. The figures relate to selected examples of facilities. The scope of the invention is not limited to the embodiments shown. Features which are critical to the invention and which can only be gathered from the figures form part of the scope of the disclosure and can advantageously develop the subject-matter of the application, on their own or in combinations shown. The individual figures show:

[0055] FIG. 1 a facility comprising two robots;

[0056] FIG. 2 a facility comprising six robots.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0057] FIG. 1 shows a facility 1, comprising: a tool 2 on which a large-area sub-assembly 3in this case, a part of an aircraft shelllies; two robots 4, 5; and a depository 6. The facility 1 also comprises: a measurement system, which consists of the measurement systems 7, 8 and 9; and a computer 10.

[0058] The sub-assembly 3 is a part of an outer shell of an aircraft fuselage which is to be reinforced with ribs or stringers 11. A first rib 11, which has been placed on the depository 6 by other robots which are not shown, can be gripped and placed on the sub-assembly 3 by the robots 4, 5. It has to be placed or positioned on the sub-assembly 3 with absolute precision.

[0059] In order for this to be possible, the facility 1 comprises multiple measurement systems 7, 8, 9 which monitor the movementsi.e. a direction of the movement, a speed of the movement, a distance travelled during the movement, a torque, a pressure force and other parametersof the robots. The measurement systems 7, 8, 9 can for example comprise theodolites, cameras, laser trackers and/or laser radar, in order to monitor in detail the individual processing steps of the robots collaborating with each other.

[0060] The assembly task is created theoretically at a workstation, which is not shown, for example using a CAD program or textual programming The finished program is then inputted into a memory unit 31 of the computer 10 and comprises the theoretical nominal data for executing all the individual processing steps for fulfilling the assembly task.

[0061] The computer 10 comprises a computational unit 30. The computational unit 30 can comprise the memory unit 31, a transmission interface 32 and a communications interface 33. The computational unit 30 derives subroutines for each of the two robots 4, 5 collaborating with each other from the program which is stored in the memory unit 31, wherein said subroutines represent the individual adjusted processing steps of the respective robot. These subroutines are transmitted to the two robots 4, 5 via the transmission interface 32.

[0062] The assembly task is, for example, that the two robots 4, 5 pick up the stringer 11 from the depository 6, place the stringer 11 on the sub-assembly 3 in an absolutely precise position, and preferably connect it to the sub-assembly 3. To this end, a virtual co-ordinate system of the aircraft can for example be spanned with the aid of the measurement systems 7, 8, 9 and virtual and/or actual operatives, wherein the sub-assembly 3 is positioned in an absolutely precise position, and the stringers 11 can consequently also be placed in an absolutely precise position on the sub-assembly 3, in said co-ordinate system.

[0063] Since it is not possible to assemble the stringers 11 in an absolutely precise position on the sub-assembly 3 using the robots 4, 5 alone due to tolerance chains, the assembly precision is achieved by the measurement systems 7, 8, 9 monitoring all the movements of the robots 4, 5 and transmitting the measurement results obtained to the computer 10 via the communications interface 33. These measured actual data of the robot movement can be compared in the computational unit 30 with the predetermined nominal data of the theoretically created program. If this comparison reveals deviations between the actual movement and the nominal movement, the program can generate changes in order for example to automatically adapt the measured actual value to the predetermined nominal value of the theoretical programming, by modifying for example one parameter of the robot movement, and/or to automatically optimise one or more processing steps of the robots 4, 5 collaborating with each other.

[0064] FIG. 2 relates to a facility 101 comprising six robots 104, 105 which collaborate with each other and collectively place stringers 111 on a sub-assembly. Each of the robots 104, 105 has for example six degrees of freedom. In this facility 101, the robot movements and other parameters of the robots 104, 105 are again monitored by one or more measurement systems. In FIG. 2, only the measurement system 107 is shown. Other measurement systems can for example be attached to a ceiling (not shown) and/or a wall (not shown). This facility 101 also comprises a computer 110 which corresponds to the computer 10 of FIG. 1 and is therefore not described again here. The assembly task is also executed in a way corresponding to the assembly task described with respect to FIG. 1, other than that the collaboration between six robots 104, 105 and monitoring the parameters of all six robots 104, 105 is more complex than if there are only two robots 4, 5 collaborating with each other.

[0065] Instead of the two robots 4, 5 shown in FIG. 1 or the six robots 104, 105 shown in FIG. 2, any other expedient number of robots can be selected in accordance with the specific task, including for example one robot only, together with a measurement system which consists of one (FIG. 2) or more (FIG. 1) measurement systems.

LIST OF REFERENCE SIGNS

[0066] 1, 101 facility [0067] 2 tool [0068] 3 sub-assembly [0069] 4, 104 robot [0070] 5, 105 robot [0071] 6, 106 depository [0072] 7, 107 measurement system [0073] 8 measurement system [0074] 9 measurement system [0075] 10, 110 computer [0076] 11, 111 stringer [0077] 30 computational unit [0078] 31 memory unit [0079] 32 transmission interface [0080] 33 communications interface

[0081] Although the present invention has been described with reference to exemplary embodiments and implementations thereof, the present invention is not limited by or to such exemplary embodiments and implementations, as will be readily apparent to persons skilled in the art from the detailed description provided herein.