Transcript 1 Math Data Validation and Auto-Correction at GM using NX Check-Mate

Math Data Validation and Auto-Correction at GM using NX
Check-Mate
Ubaid U Rehman
General Motors
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Abstract
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This presentation will discuss:
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The usage of Check-Mate profiles for checking CAD
data for conformance to GM Math Data Quality (GM
MDQ) and Drafting Standards, and
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If non-conformances occur, then auto-correct the nonconformances using GM Standards
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General Motors Validation Facts
Check-Mate as globally agreed
upon CAD validation tool
Successfully implemented CheckMate at all GM Global Sites
Enforced 53 Check-Mate Checkers
as part of GM workflow
Check-Mate used as CAD Data
Assessment Tool
More than 200,000 NX parts
assessed weekly using check-mate
batch mode
Significant improvement in Math
data quality
Problem Statement

GM wastes time and money every year due to rework of improper data
quality of it’s math files
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A large percentage of these problems are caused by nonconformances to GM Math Data Quality (GM MDQ) and Drafting
Standards
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Math Data Quality Validation
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GM is using NX Check-Mate checkers and profiles to check CAD data
quality for their adherence to GM standards
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Checkers compare the math model to standards and report details that
are out of standards
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Math Data Quality Validation
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After error detection, issues are fixed manually
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Manual corrections still cost time and, hence, money
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GM Inquire Tool
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Custom Inquire Tool is used
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For searching different
object types
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To get object information
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To highlight/un-highlight
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To move objects to different
layers
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GM Preparation Tool
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Preparation tool is used
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To switch views to
wireframe mode
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Un-blank objects
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Fit and Orient Views
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To position WCS to
ACS
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Sets a flag so that
preparation becomes
part of workflow
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Execute part clean-up
Need of Global Math Data
Preparation/Auto-Correction Tool
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Currently considering combining validation and error corrections
in one tool
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Check-Mate or separate auto-correction tool?
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Eliminate running multiple tools (Inquire and Preparation Tool)
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Maintain and enhance one tool only
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Cost savings
But with auto-corrections, there is always a big question:
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What is safe to auto correct? 
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Auto Correction Categories
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Low Risks
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High Risks
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Non Topological
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Modifies Topology
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Mostly related to object
properties (File Structure)
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Updates Physical
Properties (Mass,Material)
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Product and
Manufacturing
Information
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Layer
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Color
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Display
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Drawing Standards
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Part and Object
Attributes
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View Orientation
Auto-Correcting in Modeling
Low Risk
Auto Correcting in Modeling mode
 Organizing modeling object types
 Layer / Category
 Layer / Entity
 Entity / Color
 Model View Display
 Attributes
 Object Display Properties
 Blank/Un-Blank
 Faces U-V Grids
 Non Persistent Customer Defaults
Auto-Correcting Drawing Files
Low Risk
Auto Correcting Drawing Entities as per
Drawing Standards
 Dimension Style
 Text Preferences
 Centerline Style
 Section Line Style
 Standard Drawing Notes
 Standard Symbols
rawing
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Auto-Corrections Math Data
High Risk
Design-critical geometry that can affect the design intent of
the original model
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Auto-correcting draft on ribs
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Hole position
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Part Clean-up
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Solid Body Physical Properties
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Auto midsurface generation
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Product and Manufacturing related
information
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GM’s Auto-Corrections Strategy
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GM’s strategy for auto-corrections:
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For low risk errors
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Check-Mate checkers will be allowed to fix problems
automatically, with intervention from a designer
For high risk errors
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Manual corrections to make sure changes won't affect
design intent
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Auto-Corrections Strategy
DEMO
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Thank You
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