Formal Model Engineering for Embedded Systems Using Real-Time Maude

This paper motivates why Real-Time Maude should be well suited to provide a formal semantics and formal analysis capabilities to modeling languages for embedded systems. One can then use the code generation facilities of the tools for the modeling languages to automatically synthesize Real-Time Maude verification models from design models, enabling a formal model engineering process that combines the convenience of modeling using an informal but intuitive modeling language with formal verification. We give a brief overview six fairly different modeling formalisms for which Real-Time Maude has provided the formal semantics and (possibly) formal analysis. These models include behavioral subsets of the avionics modeling standard AADL, Ptolemy II discrete-event models, two EMF-based timed model transformation systems, and a modeling language for handset software.Comment: In Proceedings AMMSE 2011, arXiv:1106.596

Extending the Real-Time Maude Semantics of Ptolemy to Hierarchical DE Models

This paper extends our Real-Time Maude formalization of the semantics of flat Ptolemy II discrete-event (DE) models to hierarchical models, including modal models. This is a challenging task that requires combining synchronous fixed-point computations with hierarchical structure. The synthesis of a Real-Time Maude verification model from a Ptolemy II DE model, and the formal verification of the synthesized model in Real-Time Maude, have been integrated into Ptolemy II, enabling a model-engineering process that combines the convenience of Ptolemy II DE modeling and simulation with formal verification in Real-Time Maude.Comment: In Proceedings RTRTS 2010, arXiv:1009.398

Co-simulation of Event-B and Ptolemy II Models via FMI

In the framework of model-based design formal modelling, verification and simulation of safety-critical systems are supported by several methods and tools. Interfacing these tools often becomes challenging for heterogeneous systems. The FMI standard enables integration of different simulation tools through artefacts called Functional Mockup Units (FMU) [1]. The FMI standard is mainly based on the concept of scalability of the simulation as it deals with heterogeneous cyber-physical systems. The combination of discrete behaviour and continuous-time environment is a common case study in hybrid simulation. Moreover, another aspect of the FMI is to enhance the capability of the tools. Thus, a collaborative simulation between the Rodin [2] and Ptolemy [3] is leveraged by both platforms. While Event-B is enhanced by new models of computation of Ptolemy,Ptolemy leverages the expressivity and properties validation (theorem/invariant proofs) implemented by Event-B. The main rationale of the co-simulation between Event-B and Ptolemy relies on the intention of dissimilarity and complementarity of the modelling viewpoints. Event-B provides formal modelling by specifying conditions, actions and properties that manage discrete event behaviour, whereas Ptolemy gives a structural viewpoint in terms of actors, components or functions with relation to concerned behaviour. Thus, the association of Ptolemy and Event-B puts together structural and formal aspects.This paper focuses on the collaborative simulation of models supported by both Ptolemy II and Event-B. The ongoing work consists of the design of a diagrammatic co-simulation surface and its application to a controller case study

Tools for Real-Time Control Systems Co-Design : A Survey

This report presents a survey of current simulation tools in the area of integrated control and real-time systems design. Each tool is presented with a quick overview followed by a more detailed section describing comparative aspects of the tool. These aspects describe the context and purpose of the tool (scenarios, development stages, activities, and qualities/constraints being addressed) and the actual tool technology (tool architecture, inputs, outputs, modeling content, extensibility and availability). The tools presented in the survey are the following; Jitterbug and TrueTime from the Department of Automatic Control at Lund University, Sweden, AIDA and XILO from the Department of Machine Design at the Royal Institute of Technology, Sweden, Ptolemy II from the Department of Electrical Engineering and Computer Sciences at Berkeley, California, RTSIM from the RETIS Laboratory, Pisa, Italy, and Syndex and Orccad from INRIA, France. The survey also briefly describes some existing commercial tools related to the area of real-time control systems