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Nataliya Mulyar Laci Posta

Nataliya Mulyar Laci Posta. C oupling O f M ultidisciplinary M odels. Outline. Introduction: COMM within Bode-RC Rose-RT Simulink Rose-RT and Matlab/Simulink: how to couple? State-of-affairs in COMM. Boderc Project. Consequences of design decisions can be predicted as early as possible

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Nataliya Mulyar Laci Posta

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  1. Nataliya Mulyar Laci Posta CouplingOfMultidisciplinaryModels

  2. Outline • Introduction: COMM within Bode-RC • Rose-RT • Simulink • Rose-RT and Matlab/Simulink: how to couple? • State-of-affairs in COMM

  3. Boderc Project • Consequences of design decisions can be predicted as early as possible • System-level decisions can be analyzed • Trade-offs can be made between functions, price, performance, etc. Goal: improve multi-disciplinary system design, i.e. combining mechanics, electronics and informatics, such that

  4. The COMM project • COMM = Coupling of Multidisciplinary Models • 9- month duo OOTI final project • Started on 1st of December 2003

  5. Problem Description Sequential development  long development cycle Parallel development  lack of communication btw.disciplines  incorrect assumptions  problems during integration  late time-to-market Possible solution:simulate an embedded system in its intended environment

  6. COMM Project Focuses on design of Multidisciplinary Coupling Tool (MCT) Business Case

  7. Concrete Goals • Explore possibilities of coupling of tools used in MD modeling • Use Rose-RT and Matlab/Simulink as a concrete case for coupling • Get better understanding of coupling: • relation simulation-reality • the notion of time in multidisciplinary modeling

  8. Simulation Simulationcontains a set of models of one or more dynamical systems and the interaction between those systems and their environment (Jim Ledin). Model is a physical, mathematical, or other logical representation of a system/process. Simulation advances through time and solves the equations for all models at each point in time.

  9. event 1 event 2 event 3 t1 t2 t3 t4 … t1 t2 t3 Time step Simulation Two basic representation methods of simulation models: • The discrete event simulation, where time is moving forward from one change of state to the next • The time step simulation, where time is divided into intervals

  10. Simulated system environment Rose-RT SW model Matlab/ Simulink physical model MCT Target system SW HW Real vs. Simulated Discrete Discrete and/or continuous Hybrid Simulate the real-time behavior of the embedded system

  11. Set-point generator Controller Motor Encoder + Case Study Motor Control Loop Model • Criteria for case-study selection: • Low level of model complexity • Multidisciplinary aspect: SW + HW components • Interaction btw. SW and HW components

  12. Rose-RT Matlab/ Simulink Set-point generator Controller Motor Encoder + Mapping on Tools Motor Control Loop Model Centralized Software Control

  13. Rose-RT Matlab/ Simulink Set-point generator Controller Motor Encoder + Mapping on Tools Motor Control Loop Model Distributed Software Control Decision 1: select Distributed Software Control

  14. Rose-RT and Matlab/ Simulink Rose-RT Matlab/ Simulink Computing resources 1 PC or 2 PC’s? Decision 2: use a single PC for simulation

  15. Outline • Introduction: COMM within Bode-RC • Rose-RT • Simulink • Rose-RT and Matlab/Simulink: how to couple? • State-of-affairs in COMM

  16. What is Rose-RT? Software development environment for: • Creating UML models using the elements and diagrams defined in the UML • Generating complete code implementations for those models • Executing, testing and debugging models • Uses the extensibility features of the UML for real-time reactive system development

  17. Capsule port S1 Environment S2 Rose-RT from inside • Stereotypes (special form) of class • – Capsules • • Template of active objects • – Protocols • • Template of ports Ports: created and destroyed along with their capsule

  18. Ports Active objects Encapsulation shell

  19. transitionS1toS2: {int x; x = 0; p2.send(s1); p3.send(s2); … }; S1 S1 S2 S3 Capsule: Behavior • Optional hierarchical state machine (signal handler with run-to-completion semantics) S1 S2

  20. Traffic Lights example

  21. Goal: Understand the notion of time in multidisciplinary modeling Timing in Rose-RT

  22. Goal: Understand the notion of time in multidisciplinary modeling Timing in Rose-RT • Time in Rose-RT is strongly connected with the system clock • Precision is dependent on the granularity of the OS • Accuracy is not guaranteed • Timing in Rose-RT is unpredictable • Simulation in Rose-RT can be achieved only by step-by-step execution

  23. Outline • Introduction: COMM within Bode-RC • Rose-RT • Simulink • Rose-RT and Matlab/Simulink: how to couple? • State-of-affairs in COMM

  24. x (states) u (input) y (output) What is Simulink? Simulink is a software package for modeling and simulating dynamic systems process of computing a system’s states and outputs over a span of time, using information provided by the system’s model

  25. y1 (output) x1 (states) x2 (states) u1 (input) u2 (input) y2 (output) Components of a Simulink model • Continuous blocks respond continuously to changing input. • Discrete blocks respond to changes in input only at integer multiples of a fixed interval called the block’s sample time.

  26. Structure of a Simulink model • A typical Simulink model includes sources, systems and sinks. • Simulink provides: • graphical block diagram capability • drag-and-drop blocks facility

  27. Simulink Environment The Library Browser displays a tree-structured view of the Simulink block libraries installed on your system.

  28. Motor model

  29. Components of a Simulink model • Solvers A program, called ordinary differential equation (ODE) solver, updates block inputs and computes block outputs and states at intervals from the simulation start time to the simulation end time.  You can specify the solver to use in the model or when running a simulation.

  30. Goal: Understand the notion of time in multidisciplinary modeling Timing in Matlab/Simulink • The simulation time in Matlab/Simulink and real clock are not the same The amount of time it takes to run a simulation depends on - model complexity, computer’s speed, solver’s type, etc. • Simulation time and real time are not proportional Simulation time can run faster  time acceleration slower  time stretching • Facilities for scheduling and dealing with concurrencyare not offered  is not suitable for simulation of SW

  31. Goal: Understand the notion of time in multidisciplinary modeling TrueTime Real-time kernels and network transmissions can be simulated • Different processing times, priorities, and arbitrary scheduling policies in the computer nodes can be specified • Various network protocols may be evaluated • By introducing disturbing traffic on the network, the effects of unpredictability in the network communication can be studied • Limitations • Code generated by other applications cannot be directly used in TrueTime framework

  32. Outline • Introduction: COMM within Bode-RC • Rose-RT • Simulink • Rose-RT and Matlab/Simulink: how to couple? • State-of-affairs in COMM

  33. ROSE-RT MATLAB/ SIMULINK MCT ROSE-RT MATLAB/ SIMULINK Goal: Explore ways of coupling of tools used in MD modeling Rose-RT and Matlab/Simulink: How to couple? Approach 1 Approach 2 Decision 3: select loosely-coupled architecture

  34. MCT Timing request Timing request Data Data Provide timing Provide timing ROSE-RT MATLAB/ SIMULINK Goal: Explore ways of coupling of tools used in MD modeling Rose-RT and Matlab/Simulink:Where to place timing? • Not feasible due to the timing service of Rose-RT

  35. MCT Timing request Timing request Data Data Provide timing Provide timing ROSE-RT MATLAB/ SIMULINK Goal: Explore ways of coupling of tools used in MD modeling Rose-RT and Matlab/Simulink: Where to place timing? • Timing is enforced to both modeling toolsets • No advantage of Matlab/Simulink timing is taken

  36. MCT Timing request Timing request Data Data Provide timing Provide timing ROSE-RT MATLAB/ SIMULINK Goal: Explore ways of coupling of tools used in MD modeling Rose-RT and Matlab/Simulink: Where to place timing? • Rose-RT timing is not used • Matlab/Simulink provides a well-defined notion of simulation time Decision 4: use Matlab/Simulink as a timing provider

  37. Outline • Introduction: COMM within Bode-RC • Rose-RT • Simulink • Rose-RT and Matlab/Simulink: how to couple? • State-of-affairs in COMM

  38. MCT Design

  39. ToDo • Rose-RT automated step-by-step execution  changes in RTController needed (complex!) • Rose-RT timing compatibility with Simulink replacement of Windows NT Timing Services • Simulation in intended target environment  durations of execution of Rose-RT functions on a target OS should be available

  40. Questions

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