Optical robotic canopy polishing system

• US 5,067,085 A
• Filed: 05/15/1989
• Issued: 11/19/1991
• Est. Priority Date: 05/15/1989
• Status: Expired due to Fees

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Wenzel, Dennis J., McFalls, David S. II
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US07/352,600
• Time in Patent Office: 918 Days
• Field of Search: 364/474.06, 364/474.05, 364/474.37, 364/513, 364/507, 51/165.71, 51/165.72, 358/101, 358/106, 358/107, 901/41, 901/44, 901/47, 250/562, 250/563, 250/571, 250/572, 356/237
• US Class Current: 700/164
• CPC Class Codes: B25J 9/1684 Tracking a line or surface by means of sensors
• CPC Class Codes: G01N 2021/8874 Taking dimensions of defect into account
• CPC Class Codes: G01N 21/91 using penetration of dyes, e.g. fluorescent ink
• CPC Class Codes: G01N 21/9515 Objects of complex shape, e.g. examined with use of a surface follower device measuring contours and curvatures G01B11/24
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/37206 Inspection of surface
• CPC Class Codes: G05B 2219/37572 Camera, tv, vision
• CPC Class Codes: G05B 2219/45058 Grinding, polishing robot
• CPC Class Codes: G05B 2219/49362 Tool, probe at constant height to surface during machining

Abstract

A method and apparatus for providing an automated optical robotic polishing system for removing flaws in transparencies, such as transparent canopies used in aircraft. A pneumatic random orbital polishing tool attached to a robot arm is used to polish canopies to remove flaws. The flaws are removed by grinding the area surrounding the flaw and smoothing the flaw site to conform to the contour of the canopy. To identify optimum motions for the polishing tool for grinding to remove the bulk of the plastic material around a flaw, mathematical topology simulation techniques are implemented using various polishing pad pressure profiles and various polishing motions.

Claims

1. A system for removing flaws from the surface of a material, such as a transparent aircraft canopy, comprising:

a canopy;

means for obtaining a video signal representation of the surface of said canopy, wherein said means for obtaining a video signal representation of said canopy comprises means for mapping said surface of said canopy to obtain a plurality of mapped sectors, the location of said flaws being correlated with the location of said mapped sectors;

means for processing said video signal representation of said surface of said canopy to locate flaws in said surface;

means for determining an optimal grinding pattern for removing said flaws from said canopy; and

means for polishing the surface of said canopy in accordance with said grinding pattern to remove said flaws from said surface.

2. The system according to claim 1, said means for determining said optimal grinding pattern further comprising means for calculating an optimum pad pressure profile, said pad pressure profile being correlated, in accordance with said optimal grinding pattern, with the amount of material to be removed from the surface of said canopy by a grinding pad on said polishing means.

3. The system according to claim 2, wherein said pad pressure profile is determined by a second order polynomial as a function of the radius of a polishing pad.

4. The system according to claim 3, wherein said flaws are grouped in clusters to minimize the number of grinding patterns needed to remove said flaws.

5. The system according to claim 4, wherein said optimum grinding pattern is a cubic polynomial function of the radius of said polishing pad.

6. The system according to claim 5, wherein said flaws are removed by grinding a plurality of circular patterns in said surface of said canopy in accordance with said optimum grinding pattern.

7. A method of removing flaws from the surface of a material, such as transparent material used in an aircraft canopy, comprising the steps of:

obtaining a video signal representation of the surface of a canopy;

processing said video signal representation of said surface of said canopy to locate flaws in said surface;

calculating an optimal grinding pattern for removing said flaws from said canopy;

calculating a pad pressure profile, said pad pressure profile being correlated, in accordance with said optimal grinding pattern, with the amount of material to be removed from the surface of said canopy by a grinding pad on a polishing means; and

polishing the surface of said canopy in accordance with said grinding pattern to remove said flaws from said surface.

8. The method according to claim 7, wherein said pad pressure profile is a second order polynomial function of the radius of said grinding pad.

9. The method according to claim 8, wherein said flaws are grouped in clusters to minimize the number of grinding patterns needed to remove said flaws.

10. The method according to claim 9, wherein said optimum grinding pattern is a cubic polynomial function of the radius of said grinding pad.

11. The system according to claim 10, wherein said step of polishing the surface of said canopy comprises the step of grinding a plurality of circular patterns in said surface of said canopy in accordance with said optimum grinding pattern.