Robot system calibration method

Patent metadata

Field	Value
Publication number	US-9417625-B2
Application number	US-201314089911-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Nov 29, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A system for calibrating a multi-robot system includes a robot simulation device having a processor disposed therein for creating a simulation work cell of an operation of a real robot work cell, the robot simulation device configured to communicate with a robot control system controlling the robots of the real robot work cell. The simulation work cell is created based upon a predetermined layout of the real robot work cell. The system further includes a software program executed by at least one of the robot simulation device and the robot control system for calculating a part tracking offset between the simulation work cell and the real robot work cell for controlling the robots.

First claim

What is claimed is:

1. A system for calibrating a multi-robot system comprising:
a robot simulation device having a processor disposed therein for creating a simulation work cell based upon a predetermined layout of a real robot work cell, the robot simulation device communicating with a robot control system controlling robots in the real robot work cell;
a software program executed by at least one of the robot simulation device and the robot control system for calculating a part tracking offset between the simulation work cell and the real robot work cell, the robot control system using the part tracking offset to control the robots; and
the robot simulation device calculating the part tracking offset in response to a tool of the real robot work cell contacting an identifiable point on a work piece at a first position of the work piece in the real robot work cell, contacting the identifiable point on the work piece at a second position of the work piece in the real robot work cell, and jogging of the tool to a third position in a direction perpendicular to a travel direction of the work piece through the real robot work cell.

2. The system according to claim 1 , wherein the robot simulation device operates offline from the robot control system.

3. The system according to claim 1 , wherein the robot simulation device has a display providing a three-dimensional model of the multi-robot system and a work piece in the real robot work cell.

4. The system according to claim 1 , wherein the predetermined layout is based upon a manufacturing drawing of the multi-robot system.

5. The system according to claim 1 , wherein the software program establishes tracking frames in the simulation work cell through the robot simulation device.

6. The system according to claim 1 , wherein the part tracking offset is calculated based on at least one of a frame calibration executed through the robot control system and a calibration path executed through the robot control system.

7. The system according to claim 6 , wherein the frame calibration is a calculation of a work cell frame and the calibration path is a calculation of a taught path on a work piece.

8. The system according to claim 1 , wherein the part tracking offset accounts for a work piece moving on a conveyor in the real robot work cell.

9. A method for calibrating a multi-robot system comprising the steps of:
creating a simulation work cell of an operation of a real robot work cell through a robot simulation device, the simulation work cell being based on a predetermined layout of the real robot work cell;
establishing tracking frames in the simulation work cell through the robot simulation device;
determining, through a robot control system for robots in the real robot work cell, if a deviation exists between the simulation work cell and the real robot work cell;
executing a frame calibration through the robot control system to calibrate the simulation work cell with the real robot work cell for controlling the robots; and
teaching a nominal tracking frame for each of a plurality of robots of the multi-robot system including touching, by a tool of at least one robot of the plurality of robots, an identifiable point on a work piece at a first position of the work piece in the real robot work cell and touching, by the tool, the identifiable point on the work piece at a second position of the work piece in the real robot work cell.

10. The method according to claim 9 , wherein the robot simulation device is offline from the robot control system.

11. The method according to claim 9 , wherein the predetermined layout is based on a manufacturing drawing of the multi-robot system.

12. The method according to claim 9 , wherein the frame calibration is executed if the deviation exists between the simulation work cell and real robot work cell and includes the steps of:
establishing a work cell frame in the real robot work cell; and
teaching the nominal tracking frame for each of the plurality of robots of the multi-robot system through the robot control system such that the nominal tracking frame for each of the plurality of robots is at the work cell frame.

13. The method according to claim 12 , wherein teaching the nominal tracking frame includes jogging of the tool to a third position in a direction perpendicular to a travel direction of the work piece through the real robot work cell.

14. The method according to claim 12 , wherein an offset is recorded through the robot control system during the teaching of the nominal tracking frame for each robot of the plurality of robots.

15. The method according to claim 9 , wherein the calibration path includes teaching at least three non-linear points on the work piece.

16. The method of claim 9 , further comprising the steps of:
relocating, through the robot simulation device, the simulation work cell to be substantially equivalent to the real robot work cell; and
calculating a part tracking offset through the robot simulation device based on the relocation of the simulation work cell.

17. The method according to claim 16 , wherein a node map is displayed on the robot simulation device to assist a user in relocating the simulation work cell.

18. A method for calibrating a multi-robot system comprising the steps of:
creating a simulation work cell of an operation of a real robot work cell through a robot simulation device, the simulation work cell being based on a predetermined layout of the real robot work cell;
establishing tracking frames in the simulation work cell through the robot simulation device;
defining a work cell frame on the simulation work cell as being at a specified position of the work piece as the work piece travels on a conveyor, the specified position established when the work piece is initially detected before entering an operation zone, the specific positioned signaled to a controller to initiate control of the robots;
determining, through a robot control system for robots in the real robot work cell, if a deviation exists between the simulation work cell and the real robot work cell;
executing at least one of a frame calibration and a calibration path through the robot control system to calibrate the simulation work cell with the real robot work cell;
relocating, through the robot simulation device, the simulation work cell to be substantially equivalent to the real robot work cell; and
calculating a part tracking offset through the robot simulation device based on the relocation of the simulation work cell and using the part tracking offset to control the robots.

19. The method according to claim 18 , wherein the frame calibration is executed if the deviation exists between the simulation work cell and real robot work cell and includes the step of:
teaching a nominal tracking frame for each of a plurality of robots of the multi-robot system through the real robot control system such that the nominal tracking frame for each of the plurality of robots is at the work cell frame.

Assignees

• Fanuc America Corp

Inventors

• Graca Randy A
• Galloway Thomas R
• Giri Nivedhitha
• Geheb Gordon

Classifications

• B25J9/1692

  Calibration of manipulator · CPC title

• G05B2219/39013

  Locate movable manipulator relative to object, compare to stored gridpoints · CPC title

• B25J9/1671 Primary

  characterised by simulation, either to verify existing program or to create and verify new program, CAD/CAM oriented, graphic oriented programming systems · CPC title

• G05B2219/32351

  Visual, graphical animation of process · CPC title

• G05B2219/32385

  What is simulated, manufacturing process and compare results with real process · CPC title