Representing Geometry CAD information in dynamic Modelica models

Representing Geometry (CAD) information in dynamic (Modelica) models MSDL August 29 th, 2009 By Chahé Adourian

Outline n n n n n Introduction Intro to Block Diagrams (BD) Intro to CAD Assemblies Comparison BD - CAD Mapping CAD to BD Automating the process Example Conversion Conclusion Future Work

Introduction n Map CAD Assembly to Block Diagrams

Introduction n Objectives n n n Provide simple mapping CAD BD Preserve mechanical/geometric constraints Simulate mechanical behavior in BD model; n Ex. A CAD Model of Robot converted to BD for simulation of robot dynamics

Intro - Block Diagrams n n Blocks + Connections Finite Connection points (1 or 2 per block) Block Parameters Ex.

Intro - CAD Assembly n n Part and geometry Assemblies and geometric relations Example Geometric relations Infinite connection points

Intro - CAD Assembly n Part and geometry

Intro - CAD Assembly n Assembly example with geometric constraints between the parts

Intro - CAD Assembly n Ex #1: Planar Mate Geometric Relation n Before and after application

Intro - CAD Assembly n Ex #2: Axial Align Geometric Relation n Before and after application

Intro - CAD Assembly n Infinite number of connection points n Ex. Planar Mate

Comparison BD – CAD n n Block diagram is abstract CAD is geometry information rich Block diagram provides finite connections CAD geometry provides infinite connections points

Mapping CAD to BD n Mapping CAD Part to BD Block

Mapping CAD to BD n CAD versus BD Geometries Cylinder Line Point Face

Mapping CAD to BD n Mapping the infinite geometric choices using Mathematical constraints n Ex. Mapping Mate Relation to equations

Mapping CAD to BD Equations Stored in BD n

Mapping CAD to BD n Partial list of BD Assembly Relations

Automating the Process n Convert CAD Assembly to BD assembly automatically n n n Extract CAD Part Geometry Information Extract CAD Assembly Information Example Conversion

Automating the Process n Example CAD Part Geometry Information

Automating the Process n Example CAD Assembly Information

Example Conversion

Conclusion n n CAD Mechanical Assembly information converted to BD form Equivalents for CAD parts, geometries and assembly relations created CAD to BD Mapping 1 -1 Simple Mapping allows BD user to influence CAD model

Future Work n n Complete bi-directional model synchronization algorithm (BD->CAD, CAD->BD) Demonstrate BD influence on CAD model development