Method and device for operating a machine, such as a multiaxial industrial robot

• US 20050264251A1
• Filed: 05/23/2005
• Published: 12/01/2005
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Bunsendal, Jens, Hietmann, Gerhard, Bischoff, Rainer
• Granted Patent: US 7,443,124 B2
• Time in Patent Office: Days
• US Class Current: 318/563
• CPC Class Codes: B25J 9/1674 characterised by safety, monitoring, diagnostic
• CPC Class Codes: G05B 19/406 characterised by monitoring or safety G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/36495 Recording position and other parameters, current, tool diameter, voltage
• CPC Class Codes: G05B 2219/40547 End effector position using accelerometers in tip
• CPC Class Codes: G05B 2219/50197 Signature analysis, store working conditions, compare with actual

Abstract

In order to improve the safety of a machine, particularly a robot, such as a multiaxial or multiaxle industrial robot during the operation thereof, particularly in the presence of human beings, the invention provides a method for operating the machine, which is characterized in that at least one path section is traversed in monitored manner in a reference trip, that movement-characteristic operating values are continuously measured and stored as reference values and that during machine operation said operating values are also determined and compared with the stored reference values. The invention also relates to a device for performing the method.

Claims

1. Method for operating a machine, such as in particular a multiaxial industrial robot, wherein at least one path section is traversed in monitored manner in a reference trip, that movement-characteristic operating values are continuously measured and stored as reference values and that when the machine in operating said operating values are also determined and compared with the stored reference values.

2. Method according to claim 1, wherein the machine is stopped if variations are detected between the reference and operating values.

3. Method according to claim 1, wherein the comparison between the operating and reference values is performed by forming a difference.

4. Method according to claim 1, wherein the comparison between the operating and reference values is performed by the determination of correlations.

5. Method according to claim 1, wherein the comparison between reference and operating values need not take place at certain points during program performance, which is important in those cases where external influences could randomly falsify the measured signals and when stoppage was not possible, e.g. in the case of a desired contact between the robot tool and workpiece (such as during spot welding).

6. Method according to claim 1, wherein account is taken of tolerances when comparing the reference and operating values.

7. Method according to claim 1, wherein account is taken of the path movement of the robot base in the case of a robot base movement in space during the determination of operating values.

8. Method according to claim 1, wherein on starting up initially there is a move up to a reference position in space.

9. Method according to claim 8, wherein the moving up to the reference position is ensured by external sensor means monitoring the absolute position.

10. Method according to claim 7, wherein during the advance a test movement is performed, in which the operating and reference values are compared with one another.

11. Method according to claim 1, wherein for the restarting of the machine following the stopping thereof, it is initially brought in controlled manner onto the intended path.

12. Method according to claim 11, wherein a controlled comparison run is performed.

13. Method according to claim 12, wherein the consent key must be operated for the controlled comparison run.

14. Method according to claim 1, wherein during the reference and operating sequence, on movable parts of the machine, particularly the robot, or tools connected to said parts, a determination takes place of characteristic measured quantities, such as the Cartesian position, axis position, orientation, speed, acceleration, drive current and/or moments.

15. Method according to claim 1, wherein characteristic kinetic quantities of the machine, particularly the robot, are determined by means of position encoders, laser triangulation, laser trackers, ammeters, moment sensors, 3D image processing and/or inertial sensors.

16. Device for operating a machine, particularly a multiaxial industrial robot, with sensors for determining movement-characteristic operating values of movable parts of the machine, particularly the industrial robot, with a device for performing a monitored reference trip accompanied by the measurement of movement-characteristic reference values, with a storage means for storing the reference values measured during the reference trip, and with a comparator unit for comparing movement-characteristic operating values determined during machine operation with corresponding, stored reference values.

17. Device according to claim 16, characterized by a disconnection device for disconnecting the robot in the case of inadmissible variations of the operating values from the reference values.