Levels of Simulation and Simulation in Early Design

Andrea BudaMikko Seppala

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Model of the System

WORLD OF IDEAS

MODEL OF THE SYSTEM

From the ConceptTill the Detail Design

Manufacturing Process

Realization

REAL WORLD

SYSTEMAlready Existing /

Will Exist

Abstraction

PROGRESSIVE LEVEL OF ABSTACTION

abstract

detailed

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Suitable “LANGUAGES” for different level of abstractionEuRobot Example

SysML

domain specific

general purpose

Simulink

Modelica

Multi BodyMSC.Adams

Visual PhysicsMarilou

CAD

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Activity Diagram of the EuRobot Development

System Analysis and High level architecture

SYSMOD

EuR

obot

_Rul

es.p

df

SysML Model System Dynamics

Analysis

Element for …

Allocation of Key VariablesTo Subsystems …

Design (early phases)

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Design (early phases)

Control

Logic

Logic Main FlowUse Case Activity Diagram

Det

aile

d M

echa

nics

D

ynam

ics

Allocation of subsystem toGeometrical primitives

High level  mechanics model

sensors/actuators model

Virtual environment Basi

c M

echa

nics

Dyn

amic

s

Detailed CAD Design > Manufacturing

AUTOMATICCODE GENERATION

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Simulation in Conceptual Design

NEW TREND: Try to push simulation in early phasesSimulation (with different goal and level of abstraction) can be developed already in the conceptual design.

NOT only to verify properties BUT to drive the development

Traditionally: Simulation for verificationSimulation were used after detail design to verify certain propeties

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Furthermore

Enables testing and evaluating multiple virtual solutionswhen it’s mostly needed (and possible)

Shortens design cycleDrastically reduce expensive physical testReduction of uncertaties: when don’t need to wait for the final integration and hope that thing will work as planned

Simulation in Conceptual Design

IDEAL > Verification only of high fidelity VIRTUAL PROTOTYPES

Case Study: Eurobot Competition

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Modern Robot Simulators

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• Several dyanmic robot simulation environments have emerged during the last decade

• Webots, USARSim, SimRobot, AnyKode Marilou…• Common features:

– real-time dynamic multi-body simulation– kinematics simulation– realistic 3D-graphics– simulated actuators and sensors– programming or scripting library– interfaces for external control software

Modern Robot Simulators

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• Enable testing different design alternatives for SW and HW quickly

• SW can be developed without access to HW and can be dubugged efficiently

• Evaluate robot’s behavior in realistic environment

Code Generation

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Toolchain

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Schematic model•Requirements

•Architecture diagram•Represented in SysML

Behavior model•Robot logic

•Represented as a FSM in Simulink or UML

Dynamic physics simulation•Robot kinematics

•Dynamic environment•Simulated actuators and sensors

•Implemented with e.g. AnyKode Marilou

Verification & validation

Physical model•Functional prototype

Code generation

Code generation Derive

Concept Evaluation with Taguchi Method

LEGO Robot for Eurobot competition

Movement method Differential Ackerman

Target identification Camera LEGO color sensor

Obstacle detection Camera Sonar

Navigation algorithm Dead reckoning SLAM Behavior based

Object manipulation Push Grabber

Storage strategy Carry on Push in front Push underTransport one at a time

Target srategy Corn Orange Tomato

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Thank you!

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