Methods and systems for processing surface data for the manufacturing of optimum fit mating parts

• US 7,974,722 B2
• Filed: 10/12/2009
• Issued: 07/05/2011
• Est. Priority Date: 10/12/2009
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Jones, Darrell Darwin, Valenzuela, Dario I., Boyl-Davis, Theodore M.
• Primary Examiner(s): Patel; Ramesh B
• Application Number:
  US12/577,409
• Publication Number:
  US 20110087358A1
• Time in Patent Office: 631 Days
• Field of Search: 700 97- 98, 700/118, 700/163, 700/182, 700/195, 264/512, 264515-516, 345419-421, 382/154
• US Class Current: 700/98
• CPC Class Codes: G05B 19/4097 characterised by using design data to control NC machines, e.g. CAD/CAM G05B19/4093 takes precedence
• CPC Class Codes: G05B 2219/35097 Generation of cutter path, offset curve
• CPC Class Codes: G06F 2113/24 Sheet material
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]

Abstract

A computer-based method for defining a surface of a part for placement adjacent a mating surface of a base part is described. The method includes receiving raw data which defines the mating surface of the base part, smoothing the raw data, generating a stable reference frame consisting of at least one of a substantially smooth curve and surface based on the smoothed raw data, calculating a dimensional offset curve or surface using the smoothed raw data and the stable reference frame curve or surface by referencing any peaks in the smoothed raw data within a predefined range of a corresponding point in the stable reference frame curve or surface, smoothing the dimensional offset curve or surface, and outputting the dimensional offset curve or surface for utilization in fabricating the part that is to be adjacent the base part.

Claims

1. A computer-based method for defining a surface of a part for placement adjacent a mating surface of a base part, said method comprising:

receiving calibrated raw data which defines the mating surface of the base part;

smoothing the calibrated raw data;

generating a stable reference frame consisting of at least one of a substantially smooth curve or surface based on the smoothed, calibrated raw data;

calculating a dimensional offset curve or surface using the smoothed, calibrated raw data and the stable reference frame curve by referencing any peaks in the smoothed raw data within a predefined range of a corresponding point in the stable reference frame curve or surface;

smoothing the dimensional offset curve or surface; and

outputting the dimensional offset curve or surface for utilization in fabricating the part that is to be adjacent the base part.

2. A computer based method according to claim 1 wherein receiving calibrated raw data which defines the mating surface of the base part comprises:

scanning an area surrounding a plurality of pilot holes in the base part and scanning a portion of the side walls of the pilot holes, using a scanning device;

to define locations of the pilot holes; and

projecting the scan data relating to the side wall of the holes onto a plane coincidental to the surface of the hole entrances; and

defining the center of the pilot holes, the diameter of the pilot holes, and data that defines the plane of the entrances of the pilot holes.

3. A computer based method according to claim 1 wherein smoothing the raw data comprises filtering noise out of the raw data to generate a profile that substantially matches peak-to-peak values of the base part surface.

4. A computer based method according to claim 1 wherein generating a stable reference frame comprises:

receiving the smoothed, calibrated raw data points in cylindrical coordinates;

converting the smoothed, calibrated raw data points from cylindrical coordinates to Cartesian coordinates;

grouping the smoothed, calibrated raw data points into sets of data points, each set including a predefined number of the smoothed, calibrated raw data points;

predicting at least two of a new X, a new Y, and a new Z by fitting a straight line through the smoothed, calibrated raw data points of each set of the smoothed, calibrated raw data points; and

generating the stable reference frame using the new Xs and the new Ys.

5. A computer based method according to claim 1 wherein calculating a dimensional offset curve comprises comparing the stable reference frame to the smoothed, calibrated raw data points.

6. A computer based method according to claim 5 wherein comparing the stable reference frame to the smoothed, calibrated raw data points comprises:

finding the distance between a point defined by x₀=(x₀, y₀) and a line defined by two points;

x₁=(x₁, y₁) and x₂=(x₂, y₂), according to

7. A computer based method according to claim 6 further comprising:

calculating a move vector for the offset of each point by calculating the slope symmetrically over at least n+1 points on the stable reference frame according to;

8. A computer based method according to claim 6 wherein calculating a local maximum peak height comprises calculating a local maximum peak height according to d_max=MAX(d_i−

n/2, . . . , d_i+n/2) n{12, 14, . . . 22}.

9. A computer based method according to claim 1 wherein calculating a dimensional offset curve comprises applying a variable offset when the pre-smoothed raw data exceeds a threshold of variation from the stable reference frame.

10. A computer based method according to claim 1 further comprising defining a surface for a part for manufacture or modification based on the dimensional offset curve or surface.

11. A system for defining a surface of a part for placement adjacent a mating surface of a base part, the surface definition utilized in fabrication of the part, said system comprising:

a database configured to receive and store raw data relating to the surface of the base part; and

a computer configured to be coupled to said database, said computer configured to;

receive calibrated raw data which defines the mating surface of the base part and cause the calibrated raw data to be stored in said database;

smooth the calibrated raw data;

generate a stable reference frame consisting of at least one of a substantially smooth curve or surface based on the smoothed, calibrated raw data;

calculate a dimensional offset curve or surface using the smoothed, calibrated raw data and the stable reference frame curve by referencing any peaks in the smoothed raw data within a predefined range of a corresponding point in the stable reference frame curve or surface;

smooth the dimensional offset curve or surface; and

store the smoothed dimensional offset curve or surface in said database for utilization in part fabrication.

12. A system according to claim 11 further comprising a scanning device operatively coupled to said computer, wherein to receive and store the calibrated raw data said computer and said scanning device configured to:

scan an area surrounding a plurality of pilot holes in the base part and scan a portion of the side walls of the pilot holes to define locations of the pilot holes;

project the scan data relating to the side wall of the holes onto a plane coincidental to the surface of the hole entrances; and

define the center of the pilot holes, the diameter of the pilot holes, and data that defines the plane of the entrances of the pilot holes.

13. A system according to claim 11 wherein to smooth the calibrated raw data, said computer programmed to filter noise out of the raw data and generate a surface profile that substantially matches peak-to-peak values of the base part surface.

14. A system according to claim 11 wherein to generate a stable reference frame, said computer is programmed to:

convert the smoothed, calibrated raw data points to Cartesian coordinates;

group the smoothed, calibrated raw data points into sets of data points, each set including a predefined number of the smoothed, calibrated raw data points;

predict at least two of a new X, a new Y, and a new Z by fitting a straight line through the smoothed, calibrated raw data points of each set of the smoothed, calibrated raw data points; and

generate the stable reference frame using the new X, Y, and Z.

15. A system according to claim 11 wherein to calculate a dimensional offset curve, said computer is programmed to compare the stable reference frame to the smoothed, calibrated raw data points.

16. A system according to claim 15 wherein to compare the stable reference frame to the smoothed, calibrated raw data points, said computer is programmed to:

find the distance between a point defined by x₀=(x₀, y₀) and a line defined by two points;

x₁=(x₁, y₁) and x₂=(x₂, y₂), according to

17. A system according to claim 15 wherein said computer is further programmed to:

calculate a move vector for the offset of each point by calculating the slope symmetrically over at least n+1 points on the stable reference frame according to;

18. A system according to claim 11 wherein to calculate a dimensional offset curve, said computer is programmed to apply a variable offset when the pre-smoothed raw data exceeds a threshold of variation from the stable reference frame.

19. A system according to claim 11 wherein said computer is programmed to utilize the stored, smoothed dimensional offset curve or surface in said database to define a surface for a part for manufacture or modification.

20. A computer-based method for manufacturing a part, the part configured for eventual placement against a mating surface of a base part, said method comprising:

performing measurements with a laser displacement device to define the mating surface of the base part;

smoothing the data associated with the measurements;

generating a stable reference frame based on the smoothed measurement data;

calculating a dimensional offset based on the smoothed measurement data and the stable reference frame curve by referencing any peaks in the smoothed measurement data within a predefined or dynamic range of a corresponding point in the stable reference frame;

smoothing the dimensional offset; and

fabricating a part for placement adjacent the mating surface of the base part, a portion of the part defined by the smoothed dimensional offset.

21. A computer-based method according to claim 20 further comprising adding an expected error to the calculated the dimensional offset.