Data processing: generic control systems or specific application – Generic control system – apparatus or process – Optimization or adaptive control
Reexamination Certificate
1998-09-28
2001-07-03
Grant, William (Department: 2121)
Data processing: generic control systems or specific application
Generic control system, apparatus or process
Optimization or adaptive control
C700S029000
Reexamination Certificate
active
06256546
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to numerical control (NC) processing and more particularly to developing a deformation model between an in-process part and a model of the nominal part and using the deformation model to modify nominal NC tool and inspection paths for processing the in-process part.
NC processing operations generally allow direct linkage of shop floor processes (e.g., forging, machining or inspecting) with a mathematically exact description of a carefully designed part also referred to as a nominal model. In these types of NC processing operations, it is not unusual for an in-process part to vary from the nominal model. This variation can result in excessive setup time or even scrap. For example, consider an NC drilling operation of a sheet metal part for a combustor with a laser tool. In this NC drilling operation, a rotary table supports the sheet metal part while the laser tool drills boring holes in the part at a specific angle. An NC program uses nominal NC tool paths designed for the nominal model to drill the boring holes in the part. A problem with this operation is that the actual in-process part varies or is deformed from the nominal model. This causes the laser tool to drill the boring holes in improper locations along the surface of the in-process part. A part that has holes drilled into improper locations along its surface will typically have to be discarded as scrap. In order to avoid this NC processing error and other similar errors, there is a need for a system and a method that can modify the nominal NC tool paths to more closely match the in-process part.
BRIEF SUMMARY OF THE INVENTION
This invention is able to modify the nominal NC tool paths to more closely match the in-process part by using shape measurements of the part to modify the NC control paths used in subsequent operations. From the shape measurements on the surface of the in-process part, a mathematical mapping is generated which approximates the deformation of the part as measured against the nominal model. The mapping is applied to the tool paths in the coordinate space of the original part in order to modify those tool paths to travel in the distorted coordinate space of the in-process part. A result of this invention is that local features may be machined into the in-process parts in reasonable locations, and non contact measurement systems as well as surface finishing systems can travel at a more constant distance from the surface of the in-process part.
This invention provides a system, a method and an article of manufacture for NC processing of an in-process part. In the system embodiment there is a nominal model of the in-process part. A measuring means measures a series of n points on the in-process part. A processor generates a deformation model that approximates the deformation of the measured part relative to the nominal model. The processor comprises a determining means for determining a plurality of mapping functions for mapping point locations from the nominal model to approximate measured locations of points on the in-process part. An optimizing means optimizes the plurality of mapping functions to minimize the distance between the point locations from the nominal model to the measured locations of points on the in-process part. A transforming means transforms the point locations from the nominal model to the measured locations of points on the in-process part according to the plurality of optimized mapping functions. A computerized numerical controller controls the processing of the in-process part according to the deformation model. Both the method and the article of manufacture embodiments of this invention are similar in scope to the system embodiment.
REFERENCES:
patent: 4370721 (1983-01-01), Berenberg et al.
patent: 4382215 (1983-05-01), Barlow et al.
patent: 5016199 (1991-05-01), McMurty et al.
patent: 5208763 (1993-05-01), Hong et al.
patent: 5446673 (1995-08-01), Bauer et al.
patent: 5529441 (1996-06-01), Kosmowski et al.
patent: 5552992 (1996-09-01), Hunter
patent: 5873822 (1999-02-01), Ferre et al.
patent: 5903459 (1999-05-01), Greenwood et al.
patent: 5917726 (1999-06-01), Pryor
patent: WO930948 (1993-05-01), None
Graham Michael Evans
Jackson John Dennis
Breedlove Jill M.
General Electric Company
Goldman David C.
Grant William
Rapp Chad
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