System for Positioning Micro Tool of Micro Machine and Method Thereof

• US 20110228050A1
• Filed: 01/13/2010
• Published: 09/22/2011
• Est. Priority Date: 01/13/2009
• Status: Active Grant

• Current Assignee: Chung-Yuan Christian University
• Original Assignee: Chung-Yuan Christian University
• Inventors: WANG, SHIH-MING, Chung, Chia-You, Lin, Chih-Chun
• Granted Patent: US 8,872,913 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: G05B 19/4015 going to a reference at the beginning of machine cycle, e.g. for calibration
• CPC Class Codes: G06T 2207/10012 Stereo images
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

The present invention discloses a system for positioning micro tool of micro machine is provided in this invention, wherein the system comprises a stereo-photographing device, an image analysis system, a PC-based controller, and a micro machine. The image analysis system can analyze position of the micro tool of the micro machine and work piece by using algorithm, and the micro tool is then positioned to a pre-determined location. A method for positioning micro tool of the micro machine is also provided in this invention.

Claims

1. A system for positioning micro tool of a micro machine, comprising:

a first image capturing device and a second image capturing device, for capturing horizontal and vertical images of said micro tool and a workpiece;

a positioning device, comprising;

an image input interface for receiving said horizontal and vertical images of said micro tool and said workpiece captured by said first image capturing device and said second image capturing device;

means for analyzing image edge of said horizontal and vertical images of said micro tool and said workpiece into border horizontal and vertical images of said micro tool and said workpiece;

means for analyzing relative allocation of said border horizontal and vertical images of said micro tool and said workpiece into location discrepancies of said micro tool and said workpiece; and

an output interface for transferring out said location discrepancies of said micro tool and said workpiece; and

a controller for receiving data of said location discrepancies of said micro tool and said workpiece to position said micro tool into precise location.

2. The system for positioning micro tool of said micro machine according to claim 1, wherein said means for analyzing image edge can be Sobel edge detection method, Laplace of Gaussian edge detection method, or Canny edge detection method.

3. The system for positioning micro tool of said micro machine according to claim 1, wherein said means for analyzing image edge uses Canny algorithm to calculate edge of said micro tool and said workpiece.

4. The system for positioning micro tool of said micro machine according to claim 3, wherein said means for analyzing relative allocation comprises:

calculating vertical pixel discrepancy of said micro tool tip to a processing point of the workpiece;

calculating horizontal pixel discrepancy of said micro tool center point to the processing point of the workpiece; and

transferring pixel unit of said vertical and horizontal pixel discrepancies into length unit to obtain locational discrepancies from said micro tool to the workpiece.

5. The system for positioning micro tool of said micro machine according to claim 3, wherein resolutions of said first and second image capturing devices are calibrated before capturing said horizontal and vertical images.

6. A positioning system, comprising:

a micro machine, including;

a micro tool for processing a precision working to a workpiece;

a platform for providing a base to processing said workpiece; and

a precision arm for controlling a position of said micro tool;

a stereo image capturing device for capturing a stereo images of said micro tool and said workpiece; and

a positioning device, including;

an image input interface for receiving said stereo images of said micro tool and said workpiece;

means for analyzing image edge of said stereo images of said micro tool and said workpiece into border images of said micro tool and said workpiece;

means for analyzing relative allocation of said border images of said micro tool and said workpiece into location discrepancies of said micro tool and said workpiece; and

an output interface for transferring out said location discrepancies of said micro tool and said workpiece; and

a controller for receiving data of said location discrepancies of said micro tool and said workpiece to position said micro tool into precise location.

7. The positioning system according to claim 6, wherein said means for analyzing image edge can be Sobel edge detection method, Laplace of Gaussian edge detection method, or Canny edge detection method.

8. The positioning system according to claim 6, wherein said means for analyzing image edge uses Canny algorithm to calculate edge of said micro tool and said workpiece.

9. The positioning system according to claim 8, wherein said means for analyzing relative allocation comprises:

calculating vertical pixel discrepancy of said micro tool tip to a processing point of the workpiece;

calculating horizontal pixel discrepancy of said micro tool center point to the processing point of the workpiece; and

transferring pixel unit of said vertical and horizontal pixel discrepancies into length unit to obtain locational discrepancies from said micro tool to the workpiece.

10. The positioning system according to claim 9, wherein said stereo image capturing device comprises a first image capturing device and a second image capturing device.

11. The positioning system according to claim 10, wherein said stereo images include horizontal and vertical images.

12. The positioning system according to claim 8, wherein resolutions of said first and second image capturing devices are calibrated before capturing said horizontal and vertical images.

13. A positioning method, comprising:

providing a stereo image capturing device;

providing a tip of a micro tool and a workpiece into a vision of said stereo image capturing device;

capturing images of said micro tool and said workpiece by using said stereo image capturing device;

analyzing borders in said images of said micro tool and said workpiece;

calculating positions of said micro tool and said workpiece according to said borders in said images of said micro tool and said workpiece;

calculating a deviation of said micro tool; and

positioning said micro tool.

14. The positioning method according to claim 13, wherein said stereo image capturing device comprises a first image capturing device and a second image capturing device for capturing horizontal and vertical images of said micro tool and said workpiece.

15. The positioning method according to claim 14, wherein said first image capturing device and said second image capturing device are CCD or CMOS digital cameras.

16. The positioning method according to claim 15, further comprising a step of calibrating resolution of said first image capturing device and said second image capturing device.

17. The positioning method according to claim 16, wherein said step of analyzing said borders in said images of said micro tool and said workpiece comprises Sobel edge detection method, Laplace of Gaussian edge detection method, or Canny edge detection method.

18. The positioning method according to claim 16, wherein said step of analyzing said borders in said images of said micro tool and said workpiece is Canny edge detection method.

19. The positioning method according to claim 18, wherein said step of calculating said positions of said micro tool and said workpiece comprises:

calculating vertical pixel discrepancy of said micro tool tip to a processing point of the workpiece; and

calculating horizontal pixel discrepancy of said micro tool center point to the processing point of the workpiece.

20. The positioning method according to claim 19, wherein said step of calculating said deviation of said micro tool comprises transferring pixel unit of said vertical and horizontal pixel discrepancies into length unit to obtain locational discrepancies from said micro tool to the workpiece.

21. A position deviation detecting method for micro tool of a micro machine, comprising:

providing a stereo image capturing device;

providing a tip of said micro tool and a workpiece into a vision of said stereo image capturing device;

capturing images of said micro tool and said workpiece by using said stereo image capturing device;

analyzing borders in said images of said micro tool and said workpiece;

calculating positions of said micro tool and said workpiece according to said borders in said images of said micro tool and said workpiece; and

calculating a deviation of said micro tool.

22. The position deviation detecting method for micro tool of said micro machine according to claim 21, wherein said stereo image capturing device comprises a first image capturing device and a second image capturing device for capturing horizontal and vertical images of said micro tool and said workpiece.

23. The position deviation detecting method for micro tool of said micro machine according to claim 22, wherein said first image capturing device and said second image capturing device are CCD or CMOS digital cameras.

24. The position deviation detecting method for micro tool of said micro machine according to claim 23, further comprising a step of calibrating resolution of said first image capturing device and said second image capturing device.

25. The position deviation detecting method for micro tool of said micro machine according to claim 24, wherein said step of analyzing said borders in said images of said micro tool and said workpiece comprises Sobel edge detection method, Laplace of Gaussian edge detection method, or Canny edge detection method.

26. The position deviation detecting method for micro tool of said micro machine according to claim 24, wherein said step of analyzing said borders in said images of said micro tool and said workpiece is Canny edge detection method.

27. The position deviation detecting method for micro tool of said micro machine according to claim 26, wherein said step of calculating said positions of said micro tool and said workpiece comprises:

calculating vertical pixel discrepancy of said micro tool tip to a processing point of the workpiece; and

calculating horizontal pixel discrepancy of said micro tool center point to the processing point of the workpiece.

28. The position deviation detecting method for micro tool of said micro machine according to claim 27, wherein said step of calculating said deviation of said micro tool comprises transferring pixel unit of said vertical and horizontal pixel discrepancies into length unit to obtain locational discrepancies from said micro tool to the workpiece.