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

Ubaid U Rehman

General Motors

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Abstract

This presentation will discuss:

The usage of Check-Mate profiles for checking CAD data for conformance to GM Math Data Quality (GM MDQ) and Drafting Standards, and

If non-conformances occur, then auto-correct the non-conformances using GM Standards

General Motors Validation Facts

Check-Mate as globally agreed upon CAD validation tool

Successfully implemented Check-Mate 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

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Problem Statement

GM wastes time and money every year due to rework of improper data quality of it’s math files

A large percentage of these problems are caused by non-conformances to GM Math Data Quality (GM MDQ) and Drafting Standards

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Math Data Quality Validation

GM is using NX Check-Mate checkers and profiles to check CAD data quality for their adherence to GM standards

Checkers compare the math model to standards and report details that

are out of standards

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Math Data Quality Validation

After error detection, issues are fixed manually

Manual corrections still cost time and, hence, money

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GM Inquire Tool

Custom Inquire Tool is used

For searching different object types

To get object information

To highlight/un-highlight

To move objects to different layers

GM Preparation Tool

Preparation tool is used

To switch views to wireframe mode

Un-blank objects

Fit and Orient Views

To position WCS to ACS

Sets a flag so that preparation becomes part of workflow

Execute part clean-up

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Need of Global Math Data Preparation/Auto-Correction Tool

Currently considering combining validation and error corrections in one tool

Check-Mate or separate auto-correction tool?

Eliminate running multiple tools (Inquire and Preparation Tool)

Maintain and enhance one tool only

Cost savings

But with auto-corrections, there is always a big question:

What is safe to auto correct?

Auto Correction Categories

Low Risks

Non Topological

Mostly related to object properties (File Structure)

Layer

Color

Display

Drawing Standards

Part and Object Attributes

View Orientation

High Risks

Modifies Topology

Updates Physical Properties (Mass,Material)

Product and Manufacturing Information

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

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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

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Auto-Corrections Math Data

Design-critical geometry that can affect the design intent of the original model

Auto-correcting draft on ribs Hole position Part Clean-up Solid Body Physical Properties Auto midsurface generation Product and Manufacturing related

information

High Risk

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GM’s Auto-Corrections Strategy

GM’s strategy for auto-corrections:

For low risk errors

Check-Mate checkers will be allowed to fix problems automatically, with intervention from a designer

For high risk errors

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