Method and apparatus for transforming a part periphery to be cut from a patterned sheet material

• US 6,434,444 B2
• Filed: 03/11/1998
• Issued: 08/13/2002
• Est. Priority Date: 03/12/1997
• Status: Expired due to Term

• Current Assignee: Gerber Scientific International Incorporated (Lectra SA)
• Original Assignee: Gerber Technology Inc.
• Inventors: Herman, James S. Jr.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): RODRIGUEZ, PAUL L
• Application Number:
  US09/038,522
• Publication Number:
  US 20020002416A1
• Time in Patent Office: 1,616 Days
• Field of Search: 700/131, 700/134, 700/135, 700/143, 382/111, 382/170
• US Class Current: 700/135
• CPC Class Codes: B26D 2005/002 Performing a pattern matching operation
• CPC Class Codes: B26D 5/00 Arrangements for operating and controlling machines or devices for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
• CPC Class Codes: B26D 5/005 Computer numerical control means
• CPC Class Codes: B26D 7/018 Holding the work by suction
• CPC Class Codes: B26F 3/004 by means of a fluid jet methods for use of abrasive blasting for cutting B24C1/045; guns for abrasive fluid jets B24C5/02; perforating by non-mechanical means, e.g. by fluid jet B26F1/26
• CPC Class Codes: G05B 19/4068 Verifying part programme on screen, by drawing or other means
• CPC Class Codes: G05B 2219/35287 Verify, check program by drawing, display part, testpiece
• CPC Class Codes: G05B 2219/45044 Cutting

Abstract

A method and apparatus for cutting patterned sheet material to provide a predetermined relationship between a pattern characteristic and the part to be cut. An estimated position of a pattern characteristic is projected onto the sheet material and a distance between the estimated position and an actual position of the pattern characteristic is identified. A transforming program calculates a position for other pattern characteristic positions and cutting instructions are then created and executed.

Claims

1. A method of calculating an estimated position of a third occurrence of a pattern characteristic on a patterned sheet material having repeating occurrences of the pattern characteristic, comprising:

(a) projecting a first reference image onto the sheet material at a first estimated position of the pattern characteristic;

(b) visually inspecting the sheet material and the projected first reference image to identify a corresponding first pattern characteristic position;

(c) identifying a difference between the first reference image on the sheet material at the first estimated position and the corresponding first pattern characteristic position;

(d) projecting a second reference image onto the sheet material, the second reference image including a second estimated position of the pattern characteristic;

(e) visually inspecting the sheet material and the projected second reference image to identify a corresponding second actual pattern characteristic position;

(f) identifying a difference between the second reference image on the sheet material at the second estimated position and the corresponding second pattern characteristic position; and

(g) calculating a position of a third occurrence of the pattern characteristic based upon a difference between the first estimated position and the first actual pattern characteristic position, and the second estimated position and the second actual pattern characteristic position.

2. The method of claim 1, wherein calculating the position of the third occurrence includes one of a linear interpolation and linear extrapolation.

3. The method of claim 1, wherein calculating the position of the third occurrence includes one of a curve fitting interpolation and curve fitting extrapolation.

4. A method of identifying a fabric repeat characteristic in a patterned sheet material, comprising:

(a) projecting a first estimated pattern characteristic position onto the sheet material;

(b) identifying a first actual pattern characteristic position corresponding to the first estimated pattern characteristic position;

(c) projecting a second estimated pattern characteristic position onto the sheet material spaced apart from the first estimated pattern characteristic position;

(d) identifying a second actual pattern characteristic point corresponding to the second estimated pattern characteristic position; and

(e) calculating a pattern characteristic repeat frequency for a portion of the sheet material intermediate the first and the second actual pattern characteristic positions.

5. The method of claim 4, wherein calculating a pattern characteristic repeat frequency includes interpolating a portion of the sheet material intermediate two identified spaced apart actual pattern characteristic positions.

6. The method of claim 5, wherein interpolating includes one of a linear and smooth curve fitting interpolation.

7. The method of claim 4, wherein calculating a pattern characteristic repeat frequency includes extrapolating a portion of the sheet material spaced apart from two adjacent identified actual pattern characteristic positions.

8. The method of claim 7, wherein extrapolating includes one of a linear and smooth curve fitting extrapolation.

9. The method of claim 4, further comprising creating a revised pattern characteristic repeat frequency based upon the calculated pattern characteristic repeat frequency for a portion of the sheet material.

10. A method of associating an estimated pattern characteristic position and an actual pattern characteristic position located on a sheet material having a periphery, comprising:

(a) identifying a reference image of an estimated pattern characteristic position located outside the periphery of the sheet material;

(b) moving the reference image by one of an estimated pattern characteristic repeat and an actual pattern characteristic repeat to locate the reference image within the periphery of the sheet material; and

(c) projecting the reference image within the periphery of the sheet material.

11. A method of transforming an estimated pattern characteristic for a sheet material in response to a patterned sheet material having a pattern characteristic, comprising:

(a) disposing a first segment of the patterned sheet material upon a support surface;

(b) selecting a first pattern characteristic occurring in the first segment;

(c) projecting a reference image onto the first segment at an estimated position of the first pattern characteristic;

(d) visually inspecting the sheet material and the projected reference image to identify a corresponding pattern characteristic position proximal to the projected reference image;

(e) identifying a difference between the projected reference image at the estimated position and the corresponding pattern characteristic position proximal to the projected reference image; and

(f) calculating a local transformation of the estimated pattern characteristic, the local transformation corresponding to the identified difference between the projected reference image at the estimated position and the corresponding pattern characteristic position proximal to the projected reference image.

12. A method of transforming an estimated part periphery relative to a patterned sheet material, comprising:

(a) projecting an estimated position of a pattern characteristic and an estimated pattern distortion onto the sheet material including a pattern sheet bow and as pattern sheet skew in the estimated pattern distortion;

(b) identifying by visual operator inspection of the sheet material a first vector relating the projected estimated position of the pattern characteristic to a unique actual pattern characteristic position, and a second vector relating the estimated pattern distortion to an actual pattern distortion; and

(c) transforming the estimated part periphery in response to the identified vectors.

13. The method of claim 12, wherein the pattern characteristic is a match point characteristic.

14. The method of claim 12, further comprising simultaneously cutting a transformed part periphery and projecting an estimated position of a second pattern characteristic onto the sheet material.

15. The method of claim 14, further comprising simultaneously presenting a cut transformed part periphery at a picking station.

16. A method of transforming and distorting an estimated pattern for a sheet material in response to a patterned sheet material having a repeating pattern characteristic, comprising:

(a) disposing a first segment of the patterned sheet material upon a support surface;

(b) projecting a reference image onto the first segment at an estimated position of a first pattern characteristic, the reference image including an estimated fabric distortion including one of a bow and a skew;

(c) visually inspecting the first segment of the patterned sheet material to identify an actual fabric distortion;

(e) transforming the estimated pattern for the sheet material in response to the identified difference.

17. The method of claim 16, wherein transforming the estimated pattern in response to the identified difference includes adjusting the projected reference image to correspond an estimated fabric position to an actual fabric position.

18. An apparatus for transforming an estimated pattern for a sheet material in response to a patterned sheet material, comprising:

(a) a database containing coordinate information of a part periphery and a reference point corresponding to the patterned sheet material;

(b) a projector for projecting the part periphery and the reference point onto the sheet material;

(c) an input device for entering offset data representing a difference between the projected reference point and a corresponding point on the sheet material; and

(d) a controller operably connected to the database and the projector for determining a pattern characteristic position in response to the offset data, the controller selected to at least locally distort the estimated pattern for the sheet material in response to the difference between the projected reference point and a corresponding point on the sheet material.