System and method for setting the tool center point of a robotic tool

• US 8,406,922 B2
• Filed: 08/02/2010
• Issued: 03/26/2013
• Est. Priority Date: 07/31/2009
• Status: Active Grant

• Current Assignee: Fanuc Robotics America Incorporated (Fanuc Corporation)
• Original Assignee: Fanuc Robotics America Incorporated (Fanuc Corporation)
• Inventors: Nemmers, Thomas, Jenkins, Donald E., Tupper, Terry L.
• Primary Examiner(s): Jen, Ian
• Application Number:
  US12/848,728
• Publication Number:
  US 20110029132A1
• Time in Patent Office: 967 Days
• Field of Search: None
• US Class Current: 700/254
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G05B 2219/39011 Fixed camera detects deviation end effector from reference on workpiece, object

Abstract

A system for calibrating a robotic tool includes a housing including an aperture for receiving the robotic tool, an image generating device disposed in the housing and positioned to generate an image of the robotic tool received through the aperture of the housing, wherein the image generating device generates an image signal representing the image of the robotic tool, a light source disposed in the housing to backlight the robotic tool received through the aperture of the housing, and a processor responsive to the image signal for calculating and monitoring a configuration of the robotic tool.

Claims

1. A system for calibrating a robotic tool, the system comprising:

a housing including an aperture for receiving the robotic tool;

an image generating device disposed in the housing and positioned to generate an image of the robotic tool received through the aperture of the housing, wherein the image generating device generates an image signal representing the image of the robot tool;

a light source disposed in the housing to backlight the robotic tool received through the aperture of the housing; and

a processor responsive to the image signal for calculating and monitoring a configuration of the robotic tool.

2. The system according to claim 1, further comprising a calibration target device coupled to the robotic tool.

3. The system according to claim 2, wherein the calibration target device includes a main body having an aperture formed therein and an elongate stem coupled to the main body.

4. The system according to claim 1, further comprising a light diffuser disposed between the image generating device and the light source.

5. The system according to claim 1, wherein the light source is at least one light emitting diode for emitting light at a pre-determined wavelength.

6. The system according to claim 1, wherein the robotic tool is a welding tool.

7. The system according to claim 1, wherein the robotic tool is a welding tool having at least one welding wire and the image includes a silhouette of the at least one welding wire.

8. The system according to claim 1, wherein the processor is responsive to the image signal for calculating and monitoring a tool center point of the robotic tool.

9. A method for setting a tool center point of a robotic tool, the method comprising the steps of:

performing a calibration of an inspection station;

moving the robotic tool into the inspection station;

performing a setup of a robotic tool including generating a first image and a second image of the robotic tool to determine a tool center point of the robotic tool; and

defining a user tool associated with the robotic tool based an analysis of the first image and the second image of the robotic tool.

10. The method according to claim 9, wherein the inspection station includes a housing having an aperture for receiving the robotic tool.

11. The method according to claim 10, wherein the inspection station includes an image generating device disposed in the housing and positioned to generate the first image and the second image of the robotic tool received through the aperture of the housing.

12. The method according to claim 10 wherein the inspection station includes a light source disposed in the housing to backlight the robotic tool received through the aperture of the housing.

13. The method according to claim 11, wherein the step of performing a calibration of an inspection station includes positioning a calibration target device in a field-of-view of the image generating device.

14. The method according to claim 9, wherein the step of performing a calibration of an inspection station includes defining a coordinate system relative to the inspection station.

15. The method according to claim 9, further comprising the step of rotating the robotic tool 90 degrees about a pre-defined axis between the generating of the first image and the generating of the second image.

16. A method for setting a tool center point of a robotic tool, the method comprising the steps of:

a) providing an inspection station including an image generating device;

b) positioning the robotic tool in the inspection station;

c) generating a first image of the robotic tool using the image generating device;

d) locating a first point on the robotic tool based upon the first image;

e) locating a second point on the robotic tool based upon the first image;

f) rotating the robotic tool a pre-determined radial distance;

g) generating a second image of the robotic tool using the image generating device;

h) locating the first point on the robotic tool based upon the second image to define the first point in three dimensional space;

i) locating the second point on the robotic tool based upon the second image to define the second point in three dimensional space; and

j) defining the tool center point relative to the first point and the second point.

17. The method according to claim 16, wherein the inspection station includes a housing having an aperture for receiving the robotic tool.

18. The method according to claim 17 wherein the inspection station includes a light source disposed in the housing to backlight the robotic tool received through the aperture of the housing.

19. The method according to claim 16, further comprising the step of performing a calibration of an inspection station prior to the step of positioning the robotic tool in the inspection station.

20. The method according to claim 19, wherein the step of performing a calibration of an inspection station includes defining a coordinate system relative to the inspection station.