In many cases, it is more profitable to apply existing methodologies than to develop new ones. This holds, especially, for system development within the cyber-physical domain: until a certain abstraction level we can (re)use the methodologies for the software system development to benefit from the advantages of these techniques.
There are many approaches on mechatronic cyber-physical systems, however, most of them do not focus on the logical level of the system representation and loose the advantages of the abstract respresentation: a better overview, possibility to validate the system on the earlier phases, etc. For instance, the work presented in @cite_17 defines an extensive support to the components communication and time requirements, while the model discussed in @cite_12 proposes a complete model of the processes with communication. Nevertheless, in our opinion one limitation of such approaches is that the system is represented with a flat view, that is, there is only a single abstraction level for represent it. That could be a disadvantage in the project of a cyber-physical system, where experts of different domains should be able to cooperate and work to different views and abstraction levels of the system. Modeling theories for distributed hybrid system as SHIFT @cite_5 and R-Charon @cite_14 guarantee a complete simulation and compilation of the models, but they have no verification support. The same limitation is for UPPAAL @cite_16 and PHAVer @cite_9 , which provide the simulation, but a limited verification with restricted dynamics and only for small fragments.
@cite_14 @cite_9 @cite_5 @cite_16 @cite_12 @cite_17
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This paper describes the modeling language R-Charon as an extension for architectural reconfiguration to the existing distributed hybrid system modeling language Charon. The target application domain of R-Charon includes but is not limited to modular reconfigurable robots and large-scale transportation systems.While largely leaving the Charon syntax and semantics intact, R-Charon allows dynamic creation and destruction of components (agents) as well as of links (references) between the agents. As such,R-Charon is the first formal, hybrid automata based modeling language which also addresses dynamic reconfiguration. We develop and present the syntax and operational semantics for R-Charon on three levels: behavior (modes), structure (agents) and configuration (system). Abstract The hybrid χ (Chi) formalism integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. It integrates ease of modeling with a straightforward, structured operational semantics. Its ‘consistent equation semantics’ enforces state changes to be consistent with delay predicates, that combine the invariant and flow clauses of hybrid automata. Ease of modeling is ensured by means of the following concepts: (1) different classes of variables: discrete and continuous, of subclass jumping or non-jumping, and algebraic; (2) strong time determinism of alternative composition in combination with delayable guards; (3) integration of urgent and non-urgent actions; (4) differential algebraic equations as a process term as in mathematics; (5) steady-state initialization; and 6) several user-friendly syntactic extensions. Furthermore, the χ formalism incorporates several concepts for complex system specification: (1) process terms for scoping that integrate abstraction, local variables, local channels and local recursion definitions; (2) process definition and instantiation that enable process re-use, encapsulation, hierarchical and or modular composition of processes; and (3) different interaction mechanisms: handshake synchronization and synchronous communication that allow interaction between processes without sharing variables, and shared variables that enable modular composition of continuous-time or hybrid processes. The syntax and semantics are illustrated using several examples. SHIFT is a programming language for the specification and simulation of dynamic networks of hybrid automata. Such systems consist of components which can be created, interconnected and destroyed as the system evolves. Components exhibit hybrid behavior, consisting of continuous-time phases separated by discrete-event transitions. Components may evolve independently, or they may interact through their inputs, outputs and exported events. The interaction network itself may evolve. This is a tutorial paper on the tool Uppaal. Its goal is to be a short introduction on the flavor of timed automata implemented in the tool, to present its interface, and to explain how to use the tool. The contribution of the paper is to provide reference examples and modeling patterns. Existing models focus on specific aspects of distributed automation systems, e.g. communication aspects (IEC 61158) or application aspects (IEC 61131–3). Systems like IEC 61499 are directly dedicated to distributed applications but leave essential details of communication integration open. For the design of distributed automation systems it is necessary to understand the behavior of the complete system. This contribution introduces a concise model of distributed automation systems integrating communication layer of the OSI reference model with the non-distributed model of IEC 61131–3.