System and method for automated part inspection

Patent metadata

Field	Value
Publication number	US-10025289-B2
Application number	US-201514721112-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	May 26, 2015
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A system and method for automated part inspection are provided. The method comprises receiving a corrective machine tool program comprising instructions for causing a Numerical Control machine tool to machine at least one finished surface of a part, the corrective machine tool program differing from a nominal machine tool program; determining from the machine tool program a desired position and a desired orientation of an inspection tool relative to the at least one finished surface; and generating an inspection tool path program defining a movement of the inspection tool relative to the part, the inspection tool path program comprising instructions for placing the inspection probe at the desired position and the desired orientation and acquiring at least one measurement of the at least one new finished surface.

First claim

The invention claimed is:

1. A computer-implemented method for automated part inspection, the method comprising:
receiving a corrective machine tool program comprising instructions for causing a Numerical Control machine tool to machine at least one finished surface of a part, the corrective machine tool program having instructions different from instructions of a nominal machine tool program;
determining from the corrective machine tool program a desired position and a desired orientation of an inspection tool relative to the at least one finished surface;
generating an inspection tool path program defining a movement of the inspection tool relative to the part, the inspection tool path program comprising instructions for placing the inspection tool at the desired position and the desired orientation; and
moving the inspection tool according to the instructions of the inspection tool path program and acquiring at least one measurement of the at least one new finished surface.

2. The method of claim 1 , wherein the corrective machine tool program as received comprises instructions for causing the machine tool to execute a series of modified commands that replace a corresponding series of nominal commands defined in the nominal machine tool program for the part.

3. The method of claim 1 , wherein the inspection tool path program defines the movement of the inspection tool relative to the part for performing eddy current inspection of welds formed on the part.

4. The method of claim 1 , wherein the corrective machine tool program as received comprises instructions for correcting at least one defect formed on the part as a result of a welding operation performed on the part.

5. The method of claim 1 , wherein the corrective machine tool program as received comprises instructions for causing the machine tool to perform a flank and point milling operation.

6. The method of claim 1 , wherein determining from the corrective machine tool program the desired position of the inspection tool comprises determining a location of at least one defect on the part for inspection by the inspection tool.

7. The method of claim 1 , wherein generating the inspection tool path program comprises generating instructions for at least one of:
enabling a constant contact of the inspection tool with the at least one finished surface;
maintaining a constant pressure of the inspection tool on the at least one finished surface; and
orienting the inspection tool in a normal direction relative to the at least one finished surface.

8. The method of claim 7 , wherein determining from the corrective machine tool program the desired orientation of the inspection tool comprises computing at least one normal to the at least one finished surface and obtaining from the at least one normal coordinates for each point along the inspection tool path program.

9. The method of claim 1 , further comprising calibrating the inspection tool by:
receiving an eddy current signal in response to scanning of a calibration block with the inspection tool, the calibration block having an artificial defect thereon;
comparing an amplitude of the eddy current signal to a predetermined amplitude, and if the amplitude of the eddy current signal is not within a given tolerance of the predetermined amplitude, increasing a voltage applied to the inspection tool for adjusting the amplitude of the eddy current signal and repeating the scanning and comparing; and
comparing a phase angle of the eddy current signal to a predetermined phase angle, and if the phase angle of the eddy current signal is not within a given tolerance of the predetermined phase angle, rotating an angle of the eddy current signal and repeating the scanning and comparing.

10. The method of claim 9 , wherein comparing the amplitude of the eddy current signal to a predetermined amplitude and comparing the phase angle of the eddy current signal to a predetermined phase angle comprises comparing the amplitude and the phase angle pre-inspection.

11. The method of claim 9 , wherein comparing the amplitude of the eddy current signal to a predetermined amplitude is performed post-inspection.

12. A non-transitory computer readable medium having stored thereon program code executable by a processor for performing any one of claims 1 to 11 .

13. A system for automated part inspection, the system comprising:
a memory;
a processor; and
at least one application stored in the memory and executable by the processor for:
receiving a corrective machine tool program comprising instructions for causing a Numerical Control machine tool to machine at least one finished surface of a part, the corrective machine tool program having instructions different from instructions of a nominal machine tool program;
determining from the corrective machine tool program a desired position and a desired orientation of an inspection tool relative to the at least one finished surface;
generating an inspection tool path program defining a movement of the inspection tool relative to the part, the inspection tool path program comprising instructions for placing the inspection tool at the desired position and the desired orientation; and
moving the inspection tool according to the instructions of the inspection tool path program and acquiring at least one measurement of the at least one new finished surface.

14. The system of claim 13 , wherein the inspection tool path program defines the movement of the inspection tool relative to the part for performing eddy current inspection of welds formed on the part.

15. The system of claim 13 , wherein determining from the corrective machine tool program the desired position of the inspection tool comprises determining a location of at least one defect on the part for inspection by the inspection tool.

16. The system of claim 13 , wherein generating the inspection tool path program comprises generating instructions for at least one of:
enabling a constant contact of the inspection tool with the at least one finished surface;
maintaining a constant pressure of the inspection tool on the at least one finished surface; and
orienting the inspection tool in a normal direction relative to the at least one finished surface.

17. The system of claim 16 , wherein determining from the corrective machine tool program the desired orientation of the inspection tool comprises computing at least one normal to the at least one finished surface and obtaining from the at least one normal coordinates for each point along the inspection tool path program.

18. The system of claim 13 , wherein the application is further configured for calibrating the inspection tool by:
receiving an eddy current signal in response to scanning of a calibration block with the inspection tool, the calibration block having an artificial defect thereon;
comparing an amplitude of the eddy current signal to a predetermined amplitude, and if the amplitude of the eddy current signal is not within a given tolerance of the predetermined amplitude, increasing a voltage applied to the inspection tool for adjusting the amplitude of the eddy current signal and repeating the scanning and comparing; and
comparing a phase angle of the eddy current signal to a predetermined phase angle, and if the phase angle of the eddy current signal is not within a given tolerance of the predetermined phase angle, rotating an angle of the eddy current signal and repeating the scanning and comparing.

19. The system of claim 18 , wherein comparing the amplitude of the eddy current s

Assignees

• Pratt & Whitney Canada

Inventors

• Blais Mario
• Roberge Sylvain

Classifications

• G05B2219/37441

  Use nc machining program, cad data for measuring, inspection · CPC title

• G05B19/401

  characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes (G05B19/19 takes precedence) · CPC title

• G05B2219/37449

  Inspection path planner · CPC title

• G05B19/19

  characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path · CPC title

• G05B19/18 Primary

  Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of program data in numerical form (G05B19/418 takes precedence) · CPC title