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1

Physical Modeling for Automotive Applications

Terry Denery

The MathWorks

2

Better Information Earlier

Stages of Development Process

Avg

. Cos

t of S

olvi

ng P

robl

em

Pre S1 S2 S3 S5 S6 S7 S8S4

Conce

pt Solve Your Problems EarlySource: Stefan Thomke, “Experimentation Matters”, Harvard Business School Press

Design

Mf. Ram

p up

Prototyp

e

Produ

ct La

unch

Pilot P

rodu

ction

3

Better Information Earlier

Stages of Development Process

% P

robl

ems

Sol

ved

Pre S1 S2 S3 S5 S6 S7 S8S4

0%

100%

1st

prototypes

= Improved Communication

Early ‘90s

40%

Toyota’s Front-Loaded Development Initiatives

4

Better Information Earlier

Stages of Development Process

% P

robl

ems

Sol

ved

Pre S1 S2 S3 S5 S6 S7 S8S4

0%

100%

1st

prototypes

Toyota’s Front-Loaded Development Initiatives

= Improved Communication

Early ‘90s

40%= Use of CAD

Mid ‘90s

50%

5

Better Information Earlier

Stages of Development Process

% P

robl

ems

Sol

ved

Pre S1 S2 S3 S5 S6 S7 S8S4

0%

100%

1st

prototypes

= Improved Communication

Early ‘90s

40% = Use of CAD

Mid ‘90s

50%

Now

= Use of CAE

80%

Toyota’s Front-Loaded Development Initiatives

6

MATH EngineeringSimulation

MATLAB &Simulink

DomainKnowledge

ProgrammingSkill

“The Math is the Path”

General Engineering Simulation

7

MATH MechanicalSimulation

SimMechanics Dom.Know.

Prog.Skill

SimMechanics brings you further by lowering your requirementsfor mechanical domain knowledge and programming skills

Mechanical Engineering Simulation

8

MATH DrivelineSimulation

SimDriveline Dom.Know.

Prog.Skill

SimDriveline brings you even further!

Driveline Simulation

9

MATH Electric PowerSimulation

SimPowerSystems Dom.Know.

Prog.Skill

SimPowerSystems brings you further by lowering your requirementsfor electric power domain knowledge and programming skills

Electric Power Simulation

10

MATH Multi-DomainSimulation

MathWorks provides best combination of tools for Multi-Domain Simulations

Multi-Domain Simulation

Simulink Control Design DK PS

Stateflow DK. PS

SimPowerSystems DK PS

SimMechanics DK. PS

MATLAB &Simulink DK PS

SimDriveline DK PS

11

Our View on Mechanical Systems

■ They are not just mechanical, you know!■ We are The MathWorks, providers of the

leading development and implementation tools for deploying Controllers

ControllerMechanical

Device

Actuators

Sensors

Plant+u y

12

MechanicalDevice

Actuators

Sensors

Plant

SimMechanics

13

MechanicalDevice

Actuators

Sensors

Plant

SimDriveline

14

MechanicalDevice

Actuators

Sensors

Plant

SimPowerSystems

Electric Motors & Actuators

15

MechanicalDevice

Sensors

Plant

Simulink assures completesystem model

Actuators

Hydraulic ActuatorsSensors & TransducersThermodynamic Models of Engines

16

ControllerMechanical

Device

Actuators

Sensors

Plant+u y

Also, Simulate the Power System Management with SimPowerSystems

17

Automotive Electrical System● Sources

■ Generator 1.2 kW■ 65 Ah Battery

● Loads■ Rear Window Defog 150 W■ Audio System 70 W■ Power Window 100 W

– Behavior Model as Ohm load– Physical Model with electrical and mechanical 3D Model

■ Xenon Light 80 W■ Fog Light 110 W■ Fan 200 W

– Behavior Model as Ohm load– Physical Model (dc motor, relay, and fan)

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Power System ModelGenerator

Electrical Subsystems

FanElectrical Subsystems

Physical Fan Model

DC motor

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0 50 100 150 200 250 300 350 400 450 5000

200

400

600

800

time [s]

pow

er [w

]

0 50 100 150 200 250 300 350 400 450 5000

5

10

15

20

time [s]

volta

ge [V

]

Simulation Result – Bus Voltage and Power

Fan switches on

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Generator Current

0 50 100 150 200 250 300 350 400 450 5000

10

20

30

40

50

60

70

time [s]

gene

rato

r cur

rent

[A]

21

Generator Performance

22

∫ −−−−−−−−−−+−

=)(sin1

)cos()cos())sin(()sin())sin(()sin(2

2222

γαγγααγαγαγγααα

nennenwL &&

&

Modeling Mechanics in Simulink without SimMechanics

23

Modeling Mechanics in Simulink without SimMechanics

Simulink Model

24

RevoluteJoint2

RevoluteJoint1

JointsBodies

Piston Head

ConnectingRod

CrankShaft

Simulink Model

+

With SimMechanics

25

ControllerMechanical

Device

Actuators

Sensors

Plant+u y

Controller Development and Plant Modeling

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■ Control System Toolbox■ Robust Control Toolbox■ µ- Analysis and Synthesis Toolbox■ LMI Control Toolbox■ Model Predictive Control Toolbox■ Fuzzy Logic Toolbox■ Nonlinear Control Design Blockset■ System Identification Toolbox

MathWorks Control Products

27

Time

Mechanical Hardware Controller

Throwing it over the WallHardware TestSimulation

28

Time

Mechanical Hardware Controller

Throwing it over the Wall

Test Controller and MechanicalHardware together

Simulation

29

Time

Shorten Development Time

30

Time

Performance and Quality BenefitsEvaluate controller prior to commitment to mechanical hardware

Test impact of mechanical resonances on control system

Generate linear plant models for control development

Collaboration

31

Time

Costs Prediction & SavingsProvides for pre-proposal design trade-offs to investigate performance vs cost

Choose mechanical features that enable less expensive sensors and controllers

Understand limits of control system early

Collaboration

32

Double the work if a rework phase is introduced

Rework Phase

Failure

33

Additional Benefits■ Determine nominal trajectory paths for motion driving

actuators■ Identify force and power requirements of motion

driving actuators■ Validate hardware performance through Hardware-in-

the-Loop (HIL) testing

34

Attach to Electronics

Attach to Engine

Rapid Control Prototyping and HIL Simulation

MODEL

Plant Model

Controller Model

RapidControl

Prototyping

Real-Time Workshop Code

Hardware-in-the-LoopSimulation

Real-Time Workshop Code

35

Code Generation

Code Generation with Real-Time Workshop (RTW)Generate ANSI C codeUse Real-Time Workshop and xPC Target for hardware-in-the-loop (HIL) simulationsAccelerator modeGenerate C code for S-Functions and In-House codes

36

SimMechanics and CAD Translation■ The SimMechanics

model is automatically created from the mass, inertia, and mates defined in the SolidWorks assembly

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➼ Build Mechanical Component Models with SimMechanics and SimDriveline

➼ Build Power System and Actuator Component Models with SimPowerSystems

➼ Define System Models through integration with Simulink

➼ Test controller hardware through HIL

➼ Develop controls without commitment to Mechanical Hardware

➼ Build better systems, save time and money, and reduce risks

Summary