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

• US 7,443,124 B2
• Filed: 05/23/2005
• Issued: 10/28/2008
• 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: Hietmann, Gerhard, Bischoff, Rainer, Bunsendal, Jens
• Primary Examiner(s): Donovan; Lincoln
• Assistant Examiner(s): HORN, ROBERT WAYNE
• Application Number:
  US11/135,124
• Publication Number:
  US 20050264251A1
• Time in Patent Office: 1,254 Days
• Field of Search: 318/568.13
• US Class Current: 318/568.17
• 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 multi-axial 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 by sensors, and that when the multi-axial robot is moving along the path during an operating rip, current movement-characteristic operating values are also determined by the sensors and compared with the stored reference values, said movement-characteristic values including one of velocity and acceleration.

2. Method according to claim 1, wherein the multi-axial robot 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.

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 on starting up initially there is a move up to a reference position in space.

8. Method according to claim 7, wherein the moving up to the reference position is ensured by external sensor means monitoring the absolute position.

9. Method according to claim 1, wherein for a restarting of the multi-axial robot following a stopping thereof, the multi-axial robot is initially brought in a controlled manner onto an intended path.

10. Method according to claim 9, wherein a controlled comparison run is performed.

11. Method according to claim 10, wherein the consent key must be operated for the controlled comparison run.

12. Method according to claim 1, wherein during the reference and operating trips, on movable parts of the robot, a determination takes place of characteristic measured quantities.

13. Method according to claim 1, wherein characteristic kinetic quantities of the multi-axial robot are determined by means of position encoders, laser triangulation, laser trackers, ammeters, moment sensors, 3D image processing and/or inertial sensors arranged external to the robot.

14. A method in accordance with claim 1, wherein:

said movement-characteristic values include position values.

15. A method in accordance with claim 1, wherein:

the robot includes a plurality of mobile parts connected to each other at axes, and the robot includes a plurality of electric motors for moving the plurality of mobile parts about said axes and into different orientations;

said moving includes applying electric current to said electric motors to exert a torque on the plurality of mobile parts and move the plurality of mobile parts about said axes and into different orientations;

said movement-characteristic values include axis position, orientation, drive current and torques determined at the mobile parts of the robot during the reference trip and operating path.

16. A method in accordance with claim 1, wherein:

said sensors are external to the multi-axle robot.

17. A method for operating a multi-axial robot moving along a path, the method comprising the steps of:

moving the multi-axial robot along the path during a reference trip;

measuring movement-characteristic values of the multi-axial robot during the reference trip as reference values, said movement-characteristic values including values other than position values;

storing said reference values;

moving the multi-axial robot along the path during an operating trip;

measuring movement-characteristic values of the multi-axial robot during the operating trip as operating values, said movement-characteristic values including values other than position values;

comparing said operating values with said reference values during said moving of the multi-axial robot along the operating path trip;

stopping said moving of the multi-axial robot when said operating values deviate from said reference values for either longer than a predetermined time or greater than a predetermined amount.

18. A method in accordance with claim 17, further comprising:

providing sensors for measuring said movement-characteristic values;

performing a test movement of the multi-axial robot to a predetermined point;

measuring movement-characteristic values during said test movement as test values;

comparing said test values with said predetermined point to determine if said sensors are measuring said movement-characteristic values correctly.

19. A method in accordance with claim 17, wherein:

electric actuators are provide on the multi-axial robot for moving the multi-axial robot during the reference and operating trip;

said movement-characteristic values include a current used by the actuators during said moving.

20. A method in accordance with claim 17, wherein:

said movement-characteristic values include velocity values and acceleration values of the multi-axial robot during the reference trip and the operating trip.

21. Method for operating a multi-axial robot, wherein at least one path section is traversed in a monitored manner during a reference trip, during the reference trip one of velocity and acceleration are continuously measured and stored as reference values by sensors, and that when the multi-axial robot is moving during an operating trip, one of velocity and acceleration operating values are also determined by the sensors and compared with the stored reference values;

during the reference and operating trip, on movable parts of the multi-axial robot, a determination takes place of characteristic measured quantities.

22. A multi-axle robotic system, the system comprising:

a multi-axle robot movable along a path during a reference trip and an operating trip;

a sensor measuring movement-characteristic values of said robot during the reference trip as reference values, said sensor also measuring movement-characteristic values of said robot during the operating trip as operating values, said movement-characteristic values including values of one of velocity values and acceleration values of parts of said robot;

a storage unit storing said reference values;

a comparator unit comparing said operating values with said reference values during the operating trip.

23. A device in accordance with claim 22, wherein:

said robot includes a plurality of mobile parts connected to each other at axes, and said robot includes a plurality of electric motors for receiving electric current in order to generate torque to move the plurality of mobile parts about said axes and into different orientations;

said movement-characteristic values include axis position, orientation, drive current and torques determined at mobile parts of the multi-axial robot during the reference trip and operating trip.

24. A system in accordance with claim 22, wherein:

said movement-characteristic values include position values, said velocity values and said acceleration values;

an action unit is provided to stop movement of said robot when said operating values deviate from said reference values for either longer than a predetermined time or greater than a predetermined amount.

25. A system in accordance with claim 22, wherein:

said sensor is external to said multi-axle robot.