1. Reuse of simulation models
created for multiple purposes
Henric Andersson
2011-11-01
Kompetensnätverk VV&A, Stockholm

2. Presentation of the presenter
MsC in Control Engineering (1994)
Modeling and simulation of power plants at ABB
Saab Aeronautics
• Flight Control
• Project Management / Systems Engineering
• Product Line Engineering
• Research / PhD (2005 -> 2012)
The research is applied to Gripen simulators for
• Development
• Verification
• Training
Henric Andersson, Saab Aeronautics
PAGE 2
2011-11-01

3. Content
Context - Simulator Usage
Challenges in Aircraft Simulation
Product Line Engineering
Example application
Configurator implementation
Conclusions & Further work
Reflections
Henric Andersson, Saab Aeronautics
PAGE 3
2011-11-01

4. Simulator creation from models
The Product Line Approach – a concept for reuse
Decisions
Surrounding Aircraft Physic ECUs e.g. Sensors,
General Systems 2Logic for control auto-pilot cockpit configuration Comm.
models & Models Sensors of aircraft Operational
Gripen Actuat. systems Surrounding
wind 27 flight controls
HDD HDD HDD HUD HMD datalink
22 atcs
atmos
72 engine FADEC
IFF
28 fuel HDD HDD HDD HMD
ground
roll
29 hydraulic GECU
Avionics
21 air control Core radio 1
inertia AECU
33 lights radio 2
Flight Computers Tactical Computers
35 oxygen contol
BECU
forces FC 1 FC 2 TC 1 TC 2 panels
Process
32 ldg CSMU
datalink
position 34 gps ADC ACSSW & 23 COM
Avionics
34 INS
aircraftbody 34 ILS Payload and
Stores
stores
Physical Aircraft Avionics Avionics
Models Simulators
Henric Andersson, Saab Aeronautics
PAGE 4
2011-11-01

5. The values of modeling & simulation
Maturity
100%
60%
Model Based
Development
40% Traditional
Development
20%
Verbal Document Analysis Simulation Test Flight/
definition verification
Training/
Model Review Prototype Usage
PAGE 5

6. Challenges in Aircraft Simulation
Some challenges in set-up and support of large-scale simulations:
• Different operating systems & simulation platforms
• Many models ~100 including “legacy codes”
• Variants of the systems that the models represent
• Variants of “the same” model, e.g. different levels of fidelity
• Versions of models, e.g. due to error correction
• Parametric models with different sets of System Parameters
• Lack of standards & tools for collaboration
Henric Andersson, Saab Aeronautics
PAGE 6
2011-11-01

7. Model overview and classification
Surrounding Aircraft Physic ECUs e.g. Sensors,
General Systems 2Logic for control auto-pilot cockpit configuration Comm.
models & Models Sensors of aircraft Operational
Gripen Actuat. systems Surrounding
wind 27 flight controls
HDD HDD HDD HUD HMD datalink
22 atcs
atmos
72 engine FADEC
IFF
28 fuel HDD HDD HDD HMD
ground
roll
29 hydraulic GECU
Avionics
21 air control Core radio 1
inertia AECU
33 lights radio 2
Flight Computers Tactical Computers
35 oxygen contol
BECU
forces FC 1 FC 2 TC 1 TC 2 panels
32 ldg CSMU
datalink
position 34 gps ADC ACSSW & 23 COM
Avionics
34 INS
aircraftbody 34 ILS Payload and
Stores
stores
Physical Aircraft Avionics Avionics
7

8. Binding time alternatives
Process
for building and instantiating a simulation
----- ----- ----- -----
----- ----- ----- -----
Config_spec.xml Makefile Load_list RT_Config.ini
Core
Comp. Appli- AC_sim
cation
modules
Specific
Comp.
Repository Software Load of s/w Instantiation of
Check-out Build modules Simulation
Henric Andersson, Saab Aeronautics
PAGE 8
2011-11-01

9. Binding Time (1)
Check-out-time binding
Repository
Check Out
No Check Out
Feature_A?
Variant g
Yes
Check Out
Build
Variant f
Henric Andersson, Saab Aeronautics
PAGE 9
2011-11-01

10. Binding Time (2)
Compile-time binding
#if FEATURE_A
f()
#else
g()
#endif
Henric Andersson, Saab Aeronautics
PAGE 10
2011-11-01

11. Binding Time (3)
Run-time binding
if (feature_A) f() else g();
Henric Andersson, Saab Aeronautics
PAGE 11
2011-11-01

12. Binding Time overview
Binding at Check-out- Compile-time Run-time
time
Aspect
Creates Different source Different object Different
code variants code variants instances
Used for Reliable Implementation Fast
configuration oriented reconfiguration
configuration
Example When security / Target / platform Reconfiguration
IRP aspects is variation at end-user site
important
Different binding times may be used for different features
Henric Andersson, Saab Aeronautics
PAGE 12
2011-11-01

13. Organization in product line engineering
- The four essentials
Simulation Models Building of
and other simulator simulator products
components
Source: www.sei.cmu.edu

14. Saab Aeronautics
”Simulation model
development
handbook”
is related to “Core
Asset Development”
Recommended Documentation
• Simulation Model Requirement Specification (m)
• Simulation Model V&V/Test Plan
• Simulation Model Description
• Simulation Model V&V/Test Report
• Simulation Model Status Declaration (m) (m = mandatory)
Henric Andersson, Saab Aeronautics
PAGE 14
2011-11-01

15. Configuration of the simulation
- Customer Aircraft Simulation - Batch tests Other
- Variant Configuration Needs - Verification Constraints
Constraints - Training - Security
- IPR
Configurator
Tool
ciinfo
----- ----- ----- -----
----- A ----- B ----- C ----- D
Config_spec.xml Makefile Load_list RT_Config.ini
Core
Comp. Appli- Sim_
cation core
modules
Specific
Comp.
Repository Software Load of s/w Instantiation of
Check-out Build modules Simulation
Henric Andersson, Saab Aeronautics
PAGE 15
2011-11-01

16. Prototype implementation
– Tacton Configurator Studio (COTS tool)
PAGE 16

17. The utilization points of models
Collaboration
??..!!
Communication
Visualization
Decision support
Documentation
Insight
M
Create
Understanding
and deeper Insight
Automation
Data storage
Analyze
Simulation
Transformation
PAGE 17

18. Standards for V&V and reuse of models
• FMI – Functional Mock-up Interface
• promising for improved interchangeability – Modelica oriented
• SMP/SMP2 – Simulation Model Portability/Platform
• methods and tools for large scale simulations
• HLA – High Level Architecture
• for connecting real-time simulations
• For the Gripen simulators today: HLA (and FMI)
Henric Andersson, Saab Aeronautics
PAGE 18
2011-11-01

19. Conclusions and further work
Conclusions
A meta-model is develop for model variability, configuration/customization
Constraints input from PDM is needed to configure a simulation
Integration of configuration data between PDM and the simulation
environment is based on documentation
Model Interface Compatibility is crucial. The emerging FMI (Functional Mock-
up Interface) standard is promising for increased level of reuse
One condition for acceptance of model reuse is verified models
Further Work
Connection to further standards; PLMXML, FMI, SysML, & GM-VV?
• Use XML, XSD & XSLT for data storage, exchange, presentation and mapping
Validation of the configurator implementation in the application project
19

20. Reflections (about standards in general)
• Objectives and methods for verification, validation, and
documentation are well established
• Standards (in general) do not explicitly support concepts
related to Software Product
Lines and e.g. binding time
• Common meta-data representation is needed (based on
standards at ”lower levels” e.g. FMI)
• Is there a ”standards map” showing relations between
standards in the field. E.g. GM-VV related to others
Henric Andersson, Saab Aeronautics
PAGE 20
2011-11-01

21. Thank You!