1. Tool Integration of Ptolemy II EE290N Class Project Haiyang Zheng May 15 2002

2. Outline Introduction and motivation Hybrid Systems Ptolemy II models Integration with Charon tool Hybrid Systems Interchange Format (HSIF) Conclusion

3. Introduction What is a Hybrid System? Hybrid Systems are widely used in control. Different tools are developed with different purposes: modeling, simulation, verification … Verification tools involve HyTech, Kronos, CheckMate, d/dt and Charon … Tool integration has two functions: Models validity checking Tools validity checking

4. Hybrid Systems Syntax Hybrid Automaton H = Discrete States Transitions Signals + Channels Semantics State of a hybrid automaton Executions of an automaton Channel State Transition Hybrid Automaton State Transition Hybrid Automaton Channel

5. Ptolemy II Actor oriented design Block diagram with Actors, Ports and Relations Actors as producer/consumer components Models of Computation: Messaging schema Flow of control Concurrency Quoted from Prof. Edward Lee’s slides

6. Ptolemy II a hybrid system model Quoted from Xiaojun Liu’s slides

7. Charon Tool An invariant verification tool using discrete approximations based on predicate abstractions. Invariants are the predicates on the continuous variables. The violations of the predicates on the abstract system result the counter-examples for double check on the concrete system.

8. Charon Tool Agent code Composite Structure Input/Output

9. Charon Tool Mode code Finite State Machine

10. Tool Integration Integration of modeling, simulation tool with verification tool Construct Ptolemy II models from Charon models Construct Charon models from Ptolemy II models Demos

11. Problems so far … … Charon code is in text format, which makes the code parser fragile. Syntax change is even worse. Scalable issues … HyTech, d/dt, CheckMate, … … …

12. Hybrid Systems Interchange Format HSIF is to define an interchange format for hybrid system models. A descriptive language for hybrid system models. It has an XML format with according DTD. HSIF Ptolemy II CheckMate Charon d/dt Parser/Generator …

13. Tool Integration via HSIF Syntax and semantics of HSIF are specified. It is a tree-like data- structure. Entities, Relations are included, but no Ports. Standard XML parser from Sun, JAXP is used. Transitions (Relations) Entities Demo Ports ??

14. Conclusion A preliminary tool for the integration of Ptolemy II and the verification tool, Charon, was developed. A more general tool for the integration of Ptolemy II and other analysis tools with HSIF was partially developed.