Calibration and programming of robots

Patent metadata

Field	Value
Publication number	US-9833897-B2
Application number	US-201615003383-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Sep 28, 2011
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Methods includes calibrating robots without the use of external measurement equipment and copying working programs between un-calibrated robots. Both methods utilize the properties of a closed chain and the relative position of the links in the chain in order to update the kinematic models of the robots.

First claim

The invention claimed is:

1. A method for making a working program for a first robot usable with a second robot, each of the first robot and the second robot having joints connecting two flanges, the two flanges comprising a base flange and a tool flange, the method comprising:
obtaining the working program for the first robot;
selecting positions or angles based on the working program for the first robot;
moving the second robot to the positions or angles to produce a position pair data set;
estimating kinematic models of the first robot and the second robot based on a base flange offset and a tool flange center point offset between the first robot and the second robot using the position pair data set; and
performing a conversion operation on the working program based on the kinematic models.

2. The method of claim 1 , further comprising:
making a determination about whether the working program is runnable on the second robot within one or more defined tolerances.

3. The method of claim 2 , wherein making the determination comprises making a determination that the working program is not runnable on the second robot within the one or more defined tolerances; and
wherein, when the working program is not runnable on the second robot within the one or more predefined tolerances, the method further comprises:
selecting additional positions based on the working program;
moving the second robot to the additional positions to produce an extended position pair data set;
estimating revised kinematic models of the first robot and the second robot using the extended position pair data set; and
performing a conversion operation on the working program based on the revised kinematic models.

4. The method of claim 1 , further comprising:
performing a conversion operation on a second working program based on the kinematic models.

5. The method of claim 1 , wherein performing the conversion operation comprises:
applying forward kinematics to first position pair data in the working program for a first kinematic model associated with the first robot to produce a first program;
applying inverse kinematics to the first program using a second kinematic model for the second robot to produce second position pair data; and
completing the conversion operation by replacing the first position pair data in the first working program with the second position pair data to produce a converted working program that is usable with the second robot.

6. The method of claim 1 , wherein the kinematic models are based on parameters defining transformations.

7. The method of claim 6 , wherein the kinematic models are based on three types of Denavit-Hartenberg parameters.

8. The method of claim 7 , wherein the three types of Denavit-Hartenberg parameters comprise Schilling parameters, Parallel variant parameters, and RPY parameters.

9. The method of claim 6 , wherein RPY parameters are usable to modulate a last joint of each of the first robot and the second robot.

10. The method of claim 1 , wherein the kinematic models are estimated using predetermined models as a starting point.

11. Non-transitory machine-readable data storage storing instructions that are executable to make a working program for a first robot usable with a second robot, each of the first robot and the second robot having joints connecting two flanges, the two flanges comprising a base flange and a tool flange, the instructions being executable to perform operations comprising:
obtaining the working program for the first robot;
selecting positions or angles based on the working program for the first robot;
causing the second robot to move to the positions or angles to produce a position pair data set;
estimating kinematic models of the first robot and the second robot based on a base flange offset and a tool flange center point offset between the first robot and the second robot using the position pair data set; and
performing a conversion operation on the working program based on the kinematic models.

12. The non-transitory machine-readable data storage of claim 11 , wherein the operations comprise:
making a determination about whether the working program is runnable on the second robot within one or more defined tolerances.

13. The non-transitory machine-readable data storage of claim 12 , wherein making the determination comprises making a determination that the working program is not runnable on the second robot within the one or more defined tolerances; and
wherein the operations comprise, when the working program is not runnable on the second robot within the one or more predefined tolerances:
selecting additional positions based on the working program;
causing the second robot to move to the additional positions to produce an extended position pair data set;
estimating revised kinematic models of the first robot and the second robot using the extended position pair data set; and
performing a conversion operation on the working program based on the revised kinematic models.

14. The non-transitory machine-readable data storage of claim 11 , wherein the operations comprise:
performing a conversion operation on a second working program based on the kinematic models.

15. The non-transitory machine-readable data storage of claim 11 , wherein performing the conversion operation comprises:
applying forward kinematics to first position pair data in the working program for a first kinematic model associated with the first robot to produce a first program;
applying inverse kinematics to the first program using a second kinematic model for the second robot to produce second position pair data; and
completing the conversion operation by replacing the first position pair data in the first working program with the second position pair data to produce a converted working program that is usable with the second robot.

16. The non-transitory machine-readable data storage of claim 11 , wherein the kinematic models are based on parameters defining transformations.

17. The non-transitory machine-readable data storage of claim 16 , wherein the kinematic models are based on three types of Denavit-Hartenberg parameters.

18. The non-transitory machine-readable data storage of claim 17 , wherein the three types of Denavit-Hartenberg parameters comprise Schilling parameters, Parallel variant parameters, and RPY parameters.

19. The non-transitory machine-readable data storage of claim 16 , wherein RPY parameters are usable to modulate a last joint of each of the first robot and the second robot.

20. The non-transitory machine-readable data storage of claim 11 , wherein the kinematic models are estimated using predetermined models as a starting point.

Assignees

• Universal Robots As

Inventors

• Søe-Knudsen Rune
• Østergaard Esben Hallundbæk
• Petersen Henrik Gordon

Classifications

• G05B2219/40387

  Modify without repeating teaching operation · CPC title

• B25J9/1692 Primary

  Calibration of manipulator · CPC title

• G05B2219/39049

  Calibration cooperating manipulators, closed kinematic chain by bolting · CPC title

• G05B19/4083

  Adapting program, configuration · CPC title

• B25J9/0081 Primary

  with leader teach-in means · CPC title