Method for robot-assisted measurement of measurable objects

• US 9,833,904 B2
• Filed: 11/24/2015
• Issued: 12/05/2017
• Est. Priority Date: 05/17/2004
• Status: Active Grant

• Current Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Verl, Alexander
• Primary Examiner(s): Holwerda, Stephen
• Application Number:
  US14/950,699
• Publication Number:
  US 20160075029A1
• Time in Patent Office: 742 Days
• Field of Search: 700245, 700253, 700254, 700259, 901 46, 901 47, 2940704, 25055933, 25055938
• CPC Class Codes: B25J 9/1684 Tracking a line or surface by means of sensors
• CPC Class Codes: B25J 9/1692 Calibration of manipulator
• CPC Class Codes: G01B 21/00 Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
• CPC Class Codes: G05B 2219/39042 Interchange robot and reference pattern, measure by camera at same location
• CPC Class Codes: G05B 2219/45061 Measuring robot
• CPC Class Codes: Y10S 901/02 Arm motion controller

Abstract

A method for carrying out a robot-assisted measurement of measurable objects. The paths of a sensor are defined and transmitted to a robot co-ordinate system. The actual paths of the sensor guided on the robot are recorded. A plurality of measurable objects is measured, the sensor being guided with the robot along the actual paths. A compensating device makes it possible to compensate internal and/or external influences produced on the robot. The compensation stage is carried out after a determined number of measurements.

Claims

1. A method of measuring objects using a robot, the method comprising:

(a) initializing the robot by;

(1) defining paths of a sensor in a first coordinate system for measuring an object,

(2) translating the defined paths into a second coordinate system,

(3) determining actual paths of the sensor in the first coordinate system using an external calibrating device,

(4) recording a table of the actual paths of the sensor in the first and second coordinate systems, and

(5) removing the external calibrating device; and

(b) measuring at least one object by;

(1) measuring the at least one object by moving the sensor along the actual sensor path using the robot,

(2) periodically measuring a reference body with the external calibration device removed by moving the sensor using the robot to determine a point cloud,

(3) comparing the measured point cloud with a previously measured point cloud, and

(4) adjusting a robot control to compensate for changes in the kinematics of the robot based on the comparison of the point clouds.

2. The method of claim 1, wherein the reference body is measured to determine the point cloud each time the at least one object is measured.

3. The method of claim 1, wherein defining the paths of the sensor in the first coordinate system is accomplished by the external calibrating device.

4. The method of claim 3, wherein the external calibrating device measures the positions of markings that are affixed to the sensor.

5. The method of claim 3, wherein defining paths of the sensor in the first coordinate system includes manually guiding the sensor and determining the manually guided paths of the sensor with the external calibrating device.

6. The method of claim 5, further comprising:

manually uncoupling the sensor from the robot.

7. The method of claim 5, further comprising:

manually controlling the robot to move the sensor around the object to be measured.

8. The method of claim 1, wherein determining the actual paths of the sensor in the first coordinate system includes:

manually guiding the sensor and determining the manually guided paths of the sensor with the external calibrating device.

9. The method of claim 8, wherein manually guiding the sensor includes manually uncoupling the sensor from the robot.

10. The method of claim 8, wherein manually guiding the sensor includes manually controlling the robot to guide the sensor around the object.

11. The method of claim 1, further comprising:

defining the paths of the sensor around the reference body by manually guiding the sensor around the reference body and determining the manually guided paths of the sensor with the external calibrating device.

12. The method of claim 11, wherein manually guiding the sensor includes manually uncoupling the sensor from the robot.

13. The method of claim 11, wherein manually guiding the sensor includes manually controlling the robot to guide the sensor around the reference body.

14. The method if claim 1, wherein adjusting the robot control includes adjusting the table of actual paths of the sensor.