Calibration and Programming of Robots

Patent metadata

Field	Value
Publication number	US-2016136805-A1
Application number	US-201615003383-A
Country	US
Kind code	A1
Filing date	Jan 21, 2016
Priority date	Sep 28, 2011
Publication date	May 19, 2016
Grant date	—

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

1 . A method for converting a working program from a first robot R 1 to a second robot R 2 , each robot having joints connecting two flanges: a base flange and a tool flange, the method comprising:
replacing the first robot R 1 with the second robot R 2 ; providing a working program R 1 P associated with the first robot R 1 ; choosing a number of positions or angles in accordance with the working program R 1 P; moving the second robot R 2 to the chosen positions or angles to provide a position pair data set <R 1 Q, R 2 Q>; estimating kinematic models (M 1 , M 2 ) of the first and second robots (R 1 , R 2 ) based on base flange offset (T base ) and tool center point offset (T tcp ) between the first and second robots (R 1 , R 2 ) using the position pair data set <R 1 Q, R 2 Q>; and performing a working program conversion based on the estimated kinematic models (M 1 , M 2 ).

2 . The method of claim 1 , further comprising evaluating whether the working program can run on the second robot within suitably chosen tolerances.

3 . The method of claim 2 , further comprising, upon a determination that the working program cannot run on the second robot within suitably chosen tolerances, choosing an additional number of positions in accordance with the working program R 1 P, moving the second robot R 2 to the additional chosen positions to provide an extended position pair data set, estimating the kinematic models of the first and second robots using the extended position pair data set, and performing the working program conversion based on the kinematic models estimated using the extended position pair data set.

4 . The method of claim 1 , further comprising converting a second working program based on the estimated kinematic models (M 1 , M 2 ).

5 . The method of claim 1 , wherein performing the working program conversion comprises:
applying forward kinematics on all R 1 Q in R 1 P with the estimated kinematic model M 1 associated with the first robot R 1 resulting in a program R 1 K; applying inverse kinematics on the program R 1 K with the estimated kinematic model M 2 for the second robot R 2 to provide the positions R 2 Q; and completing the program conversion by replacing R 1 Q in the working program R 1 P with the corresponding R 2 Q to provide a working program R 2 P associated with the second robot R 2 .

6 . The method of claim 1 , wherein the kinematic models (M 1 , M 2 ) are determined by parameters defining transformations.

7 . The method of claim 6 , wherein the kinematic models (M 1 , M 2 ) are determined by three types of Denavit-Hartenberg parameters.

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

9 . The method of claim 6 , wherein RPY parameters are used to modulate a last joint of each robot.

10 . The method of claim 1 , wherein the kinematic models (M 1 , M 2 ) 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

• G05B2219/39049

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

• B25J9/1656 Primary

  characterised by programming, planning systems for manipulators · CPC title

• G05B19/4083

  Adapting program, configuration · CPC title

• B25J9/0081 Primary

  with leader teach-in means · CPC title