1© 2015 The MathWorks, Inc.
Modelling of Multi-Domain Systems
Dr. Michael Kitz
MathWorks
June 9, 2015
2
What Is This?
V+
V-
ω
dt
diLRiKV m
mmmbin
dt
dJbiKT mmt
3
Three Key Takeaways
Build physical models to test for integration issues early
Improve your design efficiency using domain-specific modelling
Choose the modelling strategy suited to your task
5
Product Innovation
‘Going Smart’
Model-Based Design:
a Smart Design Process
for Smart Products
Smart Product
The Challenge
Smart Design
Process
6
Smart Product
Model-Based Design
TE
ST
&
VE
RIF
ICA
TIO
N
INTEGRATION
IMPLEMENTATION
ANALYSIS – SPECIFICATION- DESIGN
MODEL
RESEARCH REQUIREMENTS
MCU DSP FPGA ASIC
Structured
TextVHDL, VerilogC, C++
Architecture
Algorithms
Schematics
TEST
CASES
Environment
Constraints
Physical Domains
TEST
CASES
PLC PAC
7
Smart Product
Model-Based Design
TE
ST
&
VE
RIF
ICA
TIO
N
INTEGRATION
IMPLEMENTATION
ANALYSIS – SPECIFICATION- DESIGN
MODEL
RESEARCH REQUIREMENTS
MCU DSP FPGA ASIC
Structured
TextVHDL, VerilogC, C++
Architecture
Algorithms
Schematics
TEST
CASES
Environment
Constraints
Physical Domains
TEST
CASES
PLC PAC
8
Programming/modelling style
Time and frequency
Continuous and discrete
Multiple physical domains
What does Multi-Domain mean?
Physical Modelling (Schematic)
Data Flow (Block diagram) Event-Driven Systems Programming Language (Textual)
10
Relative Effort of Plant Model Representations
Plant
Specification
Mathematical
Code
Programming EffortDomain Expertise
MATLAB and Simulink
Programming Effort
C, C++, FORTRAN
Domain Expertise
Programming EffortDomain Expertise
Physical Modelling Tools
Physical
Structure
Data Flow
Representation
Duration
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Data-Driven ModellingFirst Principles Modelling
Neural Networks
Physical Networks System Identification
Parameter Tuning
Programming
Block Diagram
Modelling Language
Symbolic Methods
Modelling Approaches
Statistical Methods
13
p1 p2
qp1 p2
p3
p4
Physical Network ConceptThrough & Across Variables
All nodes have the same pressure (across variable)
Sum of flows (through variables) at a node is zero
Each component must specify an equation involving the through and/or
across variables at its boundary
14
Physical Modelling with Simscape
Mechanical(translational)
Hydraulic
Thermal
Liquid
Custom Domains via Simscape Language
3-D Mechanical Systems (multi-body)
Electric Drives, Power Networks
Pneumatic Magnetic
N S
Electrical
Thermal
Mechanical(rotational)
Domain-specific modelling:
Models that reflect structure of
physical system
Common basic concept:
Bidirectional flow of power
between components
Custom domains and components
Libraries and special technology
add-ons
Co-simulate with FEM-tools
15
Model Diagram Examples
Hydraulic-mechanical modelPneumatic-mechanical model
Electrical modelThermal model (detail)
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Grid
Pitch
Yaw
Rotor
Speed
Blades
Tower
Geartrain GeneratorHub
Lift
Wind
Multi-Domain Model: Wind Turbine
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Multi-Domain Model: Wind Turbine
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Wind Turbine – Architectural Base Model
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Wind Turbine – Basic Functional Models
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Wind Turbine – Elaboration, Exploration, Integration
22
Three Key Takeaways
Build physical models to test for integration issues early
Improve your design efficiency using domain-specific modelling
Choose the modelling strategy suited to your task