assesing the use of continous-time and timed-triggered models for developing cyber-physical systems
TRANSCRIPT
Assessing the Use of Continuous-Time andTimed-Triggered Models for Designing
Cyber-Physical Systems
F. S. Goncalves, L. B. Becker
Department of Automation and Systems - DASFederal University of Santa Catarina - Brazil
IV Brazilian Symposium on ComputingSystems Engineering - SBESC
November 6, 2014
Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Cyber Physical System - CPS
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Cyber Physical System - CPS
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
ProVANT Project
• Research testbed for Cyber-physical systems:
⇒ Modeling embedded critical sys-tems;
⇒ Wireless communication;
⇒ Control systems;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Paper Goals
• Present two MoCs, CT and the TT, for designing the stability controlsystem of an UAV, which is an example of a typical CPS;
• Address the facilities and difficulties on mapping the high-level mod-els representing these two MoCs to a typical execution platform.
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Paper Goals
• Present two MoCs, CT and the TT, for designing the stability controlsystem of an UAV, which is an example of a typical CPS;
• Address the facilities and difficulties on mapping the high-level mod-els representing these two MoCs to a typical execution platform.
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
UAV Characteristics
• Vertical Take-Off and Landing(VTOL) configuration;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
UAV Characteristics
• Vertical Take-Off and Landing(VTOL) configuration;
• Physical System:
⇒ Rotors can tilt longitudinally;
⇒ Fixed tilt angle laterally;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
UAV Characteristics
• Vertical Take-Off and Landing(VTOL) configuration;
• Physical System:
⇒ Rotors can tilt longitudinally;
⇒ Fixed tilt angle laterally;
• System’s characteristics:
⇒ Underactuated mechanicalsystem;
⇒ Highly nonlinear and timevaring behavior;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Mathematical Representation
• Control equations in relation to the control inputs:
fL =1
2
√(τθh
+τψl
)2+(Fzb −
τφl
)2,
fR =1
2
√(τθh−τψl
)2+(Fzb +
τφl
)2.
(1)
αL = arctan
(τθh +
τψl
Fzb − τθl
),
αR = arctan
(τθh −
τψl
Fzb + τθl
).
(2)
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Hardware Structure
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Time-Triggerred Model Characteristics
• Composed by:
⇒ RT Entity (control);
⇒ Two Transducers (estimation and actuation);
⇒ Communication System (communication);
⇒ Three Interfaces (intEstimation, intActuation and intControl);
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Time-Triggered Model
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Simulink Model
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Continuous-Time Model Characteristcs
• Composed by a set of threads:
⇒ Control thread;
⇒ Communication thread;
⇒ Main thread;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Continuous-Time Model
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Maintainability: describe the easiness to make modifications in themodel;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Maintainability: describe the easiness to make modifications in themodel;
• Modularity / Hierarchy: analyze the capability of split the systeminto independent modules;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Maintainability: describe the easiness to make modifications in themodel;
• Modularity / Hierarchy: analyze the capability of split the systeminto independent modules;
• Expressiveness: that use of modeling language primitives to de-scribe the specification;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Simulation: verify if the specification can be used to validate theimplementation;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Simulation: verify if the specification can be used to validate theimplementation;
• Verification: capability of demonstrating formally that the systemmeets the requirements;
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Evaluation Criteria
• Simulation: verify if the specification can be used to validate theimplementation;
• Verification: capability of demonstrating formally that the systemmeets the requirements;
• Implementability: evaluating how the specification can be easilyrefined or translated into an implementation.
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Comparison Results
Evaluation Criteria TT Model CT Model
1 - Maintainability ∗∗ ∗
2 - Modularity / Hierarchy ∗∗ ∗
3 - Expressiveness 1250 1184
4 - Simulation ∗ ∗∗
5 - Verification ∗ ∗
6 - Implementability ∗ ∗
** Strong / * Adequate / 0 weak
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Comparison Results
Evaluation Criteria TT Model CT Model
1 - Maintainability ∗∗ ∗
2 - Modularity / Hierarchy ∗∗ ∗
3 - Expressiveness 1250 1184
4 - Simulation ∗ ∗∗
5 - Verification ∗ ∗
6 - Implementability ∗ ∗
** Strong / * Adequate / 0 weak
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Comparison Results
Evaluation Criteria TT Model CT Model
1 - Maintainability ∗∗ ∗
2 - Modularity / Hierarchy ∗∗ ∗
3 - Expressiveness 1250 1184
4 - Simulation ∗ ∗∗
5 - Verification ∗ ∗
6 - Implementability ∗ ∗
** Strong / * Adequate / 0 weak
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Summary
Motivation
UAV Characteristics
Time-Triggered Model
Continuous-Time Model
Comparative Analyzes
Conclusion
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Conclusions
• Both models meet the requirements and support the UAV system;
• Implementing the models in the embedded platform is not a trivialtask;
⇒ Implementation of the TT Model is more straightforward;
⇒ Implementation of the CT Model needs more expertise of theengineers.
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Conclusions
• Both models meet the requirements and support the UAV system;
• Implementing the models in the embedded platform is not a trivialtask;
⇒ Implementation of the TT Model is more straightforward;
⇒ Implementation of the CT Model needs more expertise of theengineers.
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Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Conclusions
• Both models meet the requirements and support the UAV system;
• Implementing the models in the embedded platform is not a trivialtask;
⇒ Implementation of the TT Model is more straightforward;
⇒ Implementation of the CT Model needs more expertise of theengineers.
15 of 16
Motivation UAV TT Model CT Model Analyze Conclusion Assessing the Use of CT and TT Models for Designing CPS
Conclusions
• Both models meet the requirements and support the UAV system;
• Implementing the models in the embedded platform is not a trivialtask;
⇒ Implementation of the TT Model is more straightforward;
⇒ Implementation of the CT Model needs more expertise of theengineers.
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Assessing the Use of Continuous-Time andTimed-Triggered Models for Designing
Cyber-Physical Systems
F. S. Goncalves, L. B. Becker
Department of Automation and Systems - DASFederal University of Santa Catarina - Brazil
IV Brazilian Symposium on ComputingSystems Engineering - SBESC
November 6, 2014