Top-Down Design ToolsManaging Complex Assemblies

Victor RemmersHolland Engineering Consultants BV

Tips & Techniques

© 2006 PTC2

Top-Down Design Philosophy

© 2006 PTC3

Traditional Design Approach

“Bottom-Up Design”

Design of individual components independent of the assembly

Manual approach to ensure that components fit properly and meet the design criteria

Components and those placed in sub-assemblies are brought together to develop the top-level assembly

Errors are manually identified and modifications to each component are made to make the adjustment. As assembly grows, detecting these inconsistencies and correcting them can consume a considerable amount of time

Top Level Top Level AssemblyAssembly

ComponentComponentDesignDesign

ComponentComponentDesignDesign

ComponentComponentDesignDesign

© 2006 PTC4

Possible example Bottom Up?

Mate

© 2006 PTC5

Top-Down Design Philosophy

“Top-Down Design”

Method of placing critical information in a high-level location

Communicating that information to the lower levels of the product structure

Capturing the overall design information in one centralized location

DesignDesign InformationInformation

ComponentComponent ComponentComponent ComponentComponent

© 2006 PTC6

A more integrated approach….

© 2006 PTC7

Top Down Design Stages – It is a concept.

6-Stage Process

1. Conceptual Engineering Phase

Layouts and Engineering Notebook

2. Preliminary Product Structure Phase

Pro/INTRALINK, Model Tree

3. Capturing Design Intent Phase

Skeleton Models

4. Manage Interdependencies Phase

Reference Viewer & Reference Graph

5. Communication of Design Intent Phase

Copy Geoms, Publish Geoms & Shrinkwrap

6. Population of the Assembly Phase

Automatic Component Constraints & Component Interfaces

© 2006 PTC8

The Bobcat example

© 2006 PTC9

Conceptual Engineering PhaseLayouts and Engineering Notebook

Understand Existing Situation

High-level Requirements

Space Allocation

Define New Space and Motion

2D Sketches

3D Models

Rapid Iteration & Convergence

Animations

Capture Key Design Intent

Parameters

Notes

Spreadsheets

Proprietary Data

Stage 1

© 2006 PTC10

Preliminary Product Structure Phase Pro/INTRALINK, Model Tree

Quickly define product hierarchy

• Before any of the components’ geometry is defined

Intuitive, automatic mapping to “start models”

• Templates ensure all designs share the necessary common elements such as layers, views & parameters

Foundation for efficient task distribution

Assembly Population Environments

• Pro/E menus and Model Tree pop-up menus

• Pro/INTRALINK and PDMLink

Component Creation Methods

• Empty Components; Copy from start models

• Automatic assembly of default datums

• Unplaced, Partially- & Over-Constrained Components

Stage 2

© 2006 PTC11

Capturing Design Intent Phase Skeleton Models

What needs to happen?

Capture conceptual design parameters within the context of the assembly

Capture & control critical object interfaces in a single, convenient location

How? Skeleton Models…

Centralized pathway for communication

Facilitate task distribution

Promote well-organized design environments

Enable faster, more efficient propagation of change

Special Treatment in BOMs, Simplified Reps, Drawings, Model Tree & Mass Property Calculations

Uniquely supported Scope Control Setting

Stage 3

© 2006 PTC12

Manage Interdependencies PhaseReference Viewer & Reference Graph

Stage 4

Tools to Manage References

External Reference Control

•Ensures Top-Down Design methodology is followed

• Incorporate design management rules directly into the design

•Ensures proper design reuse

Pro/INTRALINK

Model Tree

Global Reference Viewer

Reference Graph

© 2006 PTC13

Communication of Design Intent Phase Publish Geoms, Copy Geoms & Inheritance

Publish Geometry Features

Provides ability to pre-determine the geometry to be referenced by a Copy Geometry feature

Allows designers to define their interfaces to the rest of the design

Copy Geometry Features

Allows copying of all types of geometry

Surfaces, edges, curves, datums, quilts, copy/publish geometry

Retains copied geometry name and layer settings

Dependency on parent geometry can be toggled

Can be “Externalized”

External Copy Geometry

Build relationships on external models independent of an assembly

Useful for coordinate system assembly practices

Inheritance – Inherit model geometry for one-way associativity

Shrinkwrap (included in Foundation Advantage Package)

Stage 5

© 2006 PTC14

Population of the Assembly PhaseAutomatic Component Constraints & Component Interfaces

Stage 6

What tools are available for populating the assembly?

Assembly Tools

• Drag & Drop Placement

• Component Interfaces

Component Creation

• Within the context of the assembly

• Mirror Parts or Subassemblies

© 2006 PTC15

How does Top Down Design relate to company goals?

Four Goals from Upper Management

1) Cycle Time Reduction.

2) Increase User Satisfaction with Software.

3) Margin Increase.

4) Cost Reduction.

Four Goals from Upper Management

1) Cycle Time Reduction.

2) Increase User Satisfaction with Software.

3) Margin Increase.

4) Cost Reduction.

© 2006 PTC16

Why should you use it?

Benefits:

Reduced design time

Reduced errors (right the first time)

Increased quality

Better project management visibility

Concurrent engineering

Confidence in top-level regeneration

Knowledge of how modules interface

Top-level change control

Benefits:

Reduced design time

Reduced errors (right the first time)

Increased quality

Better project management visibility

Concurrent engineering

Confidence in top-level regeneration

Knowledge of how modules interface

Top-level change control

© 2006 PTC17

Example: to design an alternator...

What information should a designer need to work with most times?

Complete Top-Level Assembly

540 MB

All Skeleton Models in Top-Level

Assembly

70 MB

Neighboring Subassemblies

320MB

Subassembly, with Skeleton Model containing

all required information ~ 20 MB

© 2006 PTC18

What does an example look like?

Three PhasesPro/INTRALINKPro/CONCEPTISDX Pro/ENGINEERPro/NOTEBOOK

CONCEPTUAL DESIGN

CAPTURE DESIGN CRITERIA

DETAILED DESIGN

© 2006 PTC19

Product Definition

© 2006 PTC20

Product Definition: Engineering Layout

What it is: First thing done in design cycle First thing done in design cycle

What it is Not:What it is Not:

Used to evaluate key interface points Used to evaluate key interface points

Used to evaluate key components of project Used to evaluate key components of project

Three dimensional solids Three dimensional solids

Fully detailed Fully detailed

© 2006 PTC21

Advantages of Using a Layout

Document design information in one centralized location

Document design information before creating solid models

Investigate design options without involving the entire assembly

Easily make design changes because all of the design information is contained in one location

© 2006 PTC22

#2 Product Definition: Assembly Structure

What it is: Virtual Assembly / BOM Virtual Assembly / BOM

What it is Not: What it is Not:

Used to organize assembly & assigning of design tasks Used to organize assembly & assigning of design tasks

Used to input non-geometrical data up-front Used to input non-geometrical data up-front

Three dimensional solids Three dimensional solids

Fully detailed Fully detailed

Fully constrained Fully constrained

© 2006 PTC23

Advantages of Defining Preliminary Product Structure

Defining the product structure prior to defining geometry can assist you in organizing the assembly into manageable tasks that can be assigned to design teams or individual designers.

Associate specific library parts (that are to be used on the project) with the assembly at the start of the design, preventing confusion later.

© 2006 PTC24

Advantages of Defining Preliminary Product Structure

Cont…

Submit the assembly to Pro/INTRALINK or PDMLink and assign models to the appropriate vaults or folders.

Individual designers can focus on specific design tasks instead of on how their design is going to fit into the overall structure.

Input non-geometrical information such as the part number, designer’s name, etc., at a very early stage.

© 2006 PTC25

#3 Product Definition: Skeletons

What it is: Zero-mass geometry Zero-mass geometry

What it is Not: What it is Not:

Exact location detail Exact location detail

Three dimensional solids Three dimensional solids

Fully detailed Fully detailed

Minimized geometric detail Minimized geometric detail

© 2006 PTC26

And Definitely Not This!!

                                                       

© 2006 PTC27

Advantages of Using Skeletons

Provides a centralized location for design data

Simplifies assembly creation / visualization

Aids in assembling mechanisms

Minimizes unwanted parent-child relationships

Allows you to assemble components in any order

Controls propagation of external references

© 2006 PTC28

Central source for information

Benefits of Communicating Information From a Central Source

Task distribution

Concurrent Modeling

Managing External References

Tools Declaration

Publish Geometry

Copy Geometry

© 2006 PTC29

Hierarchy

Top_level.asm

Top_level_skeleton.prt

Sub_assy_1.asm

Sub_assy_1_skeleton.prt

Sub_assy_2.asm

Sub_assy_2_skeleton.prt

Sub_assy_x.asm

Sub_assy_x_skeleton.prt

© 2006 PTC30

3D Design … Finally!

The foundation is set … but topologically modifiable … it’s time for 3D.

With Reference Control Manager, you are safe to create your parts directly in the assembly.

© 2006 PTC31

More Than Meets The Eye!

Interchangeability:

Family of Tables

Interchange Assembly

Layout Declarations

© 2006 PTC32

Power of Top-Down Design

To Achieve Advanced Automation, consider using:

Relations

Pro/Program

© 2006 PTC33

Miscellaneous Tips

Separate Part Versus Assembly for Skeleton Features

Avoid constructing assembly-level skeleton features since the system requires that you perform all edits of these features in Assembly mode.

• The components can become an obstruction and degrade performance.

• Furthermore, you cannot easily reuse skeleton features at the assembly level in other subassemblies. By using a separate part file, you can edit the feature in Part Mode and reassemble it into many different assemblies.

Geometry Features

Place all static information in a skeleton as early as possible and place all dynamic information later in the design process cycle.

© 2006 PTC34

Miscellaneous Tips

Datums for Skeleton Models

Consider renaming skeleton datums to “sk_”

Visualization

Use simplified reps and transparency prolifically to make viewing easier

Use “display states” to highlight different items at different times

Use surfaces to clarify meaning of centerlines & axes

Conceptualization

Don’t be afraid to use simple hand sketches before delving into complex situations … it’s NOT illegal

© 2006 PTC35

Pro/E Wildfire EnhancementsHigh-performance Assembly Modeling

Lightweight Components

Represent common components with lightweight graphics for optimum display speed

Accurate mass properties and BOMs

Customizable symbolic representations

Flexible Components

Represent multiple states of a single component in an assembly

Addresses critical need for consistency between BOM and assembly model

Intelligent Regeneration

Assembly regeneration is up to 80% Faster!

© 2006 PTC36

Highlights of Top-Down Design

Capture knowledge, or design intent, allowing you to concentrate on significant issues by making the software perform tedious, repetitive calculations.

Enable the framework for interchangeability of components allowing for high-velocity product development by supporting rapid iterations of product variations.

Create a concurrent design environment by spreading project design responsibility across many organizational levels.

© 2006 PTC37

New in Advanced Assembly in Wildfire 3.0

Data Sharing Dashboard

The Data Sharing dashboard consolidates the Merge, Cutout, and Inheritance features in a modern user interface.

Enhancements to Data Sharing features in a new dashboard offer many benefits:

• Allows changing of multiple feature types at any point

• Offers a user-friendly user interface with easy access to commands

• Supports object-action workflow for increased productivity

• Consolidates Data Sharing features, such as Merge, Cutout, and Inheritance

© 2006 PTC38

New in Advanced Assembly in Wildfire 3.0 (#2)

Top-Down Design with Mechanism Assemblies

You can now design a skeleton model that includes motion.

Motion skeletons are available in Assembly, allowing motion to be incorporated into the model at the beginning of the design process. There is no longer a need to recreate an assembly to include a mechanism analysis.

You can create mechanism bodies and connections as a motion skeleton, then run a simple kinematic analysis to ensure that the skeleton provides the appropriate degrees of freedom. You can then create and assemble components to the motion skeleton. Motion skeletons are defined in the same way as normal assembly skeletons and include reference control settings. They do not appear in the assembly bill of materials.

© 2006 PTC39

POWER OF TOP DOWN DESIGN!!!