Distributed Simulation of Heterogeneous and Real-time Systems

This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-defined manner. This work leverages existing frameworks to facilitate the integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation

Distributed Simulation of Heterogeneous and Real-time Systems

This work describes a framework for distributed simulation of cyber-physical systems (CPS). Modern CPS comprise large numbers of heterogeneous components, typically designed in very different tools and languages that are not or not easily composeable. Evaluating such large systems requires tools that integrate all components in a systematic, well-definedmanner. This work leverages existing frameworks to facilitatethe integration offers validation by simulation. A framework for distributed simulation is the IEEE High-Level Architecture (HLA) compliant tool CERTI, which provides the infrastructure for co-simulation of models in various simulation environments as well as hardware components. We use CERTI in combination with Ptolemy II, an environment for modeling and simulating heterogeneous systems. In particular, we focus on models of a CPS, including the physical dynamics of a plant, the software that controls the plant, and the network that enables the communication between controllers. We describe the Ptolemy extensions for the interaction with HLA and demonstrate the approach on a flight control system simulation

Integrating AADL and FMI to Extend Virtual Integration Capability

Virtual Integration Capability is paramount to perform early validation of Cyber Physical Systems. The objective is to guide the systems engineer so as to ensure that the system under design meets multiple criteria through high-fidelity simulation. In this paper, we present an integration scheme that leverages the FMI (Functional Mock-Up interface) standard and the AADL architecture description language. Their combination allows for validation of systems combining embedded platform captured by the AADL, and FMI components that represent physical elements, either mechanical parts, or the environment. We present one approach, and demonstrator case studies

SCCharts: The Mindstorms Report

SCCharts are a visual language proposed in 2012 for specifying safety-critical reactive systems. This is the second SCCharts report towards the usability of the SCCharts visual language and its KIELER SCCharts implementation. KIELER is an open-source project which researches the pragmatics of model-based languages and related fields. Nine case-studies that were conducted between 2015 and 2019 evaluate the pros and cons in the context of small-scale Lego Mindstorms models and similar projects. Par-ticipants of the studies included undergraduate and graduate students from our local and also external facilities, as well as academics from the synchronous community. In the surveys, both the SCCharts language and the SCCharts tools are compared to other modeling and classical programming languages and tools

Semantics and Execution of Domain Specific Models

In this paper we present a two-level approach to extend the abstract syntax of models with concrete semantics. First, a light-weight execution interface for iteratable models with a generic user interface allows the tool smith to provide arbitrary execution and visualization engine implementations for his or her Domain Specific Modeling Language (DSML). We discuss how the common execution manager runtime allows co-simulations of different model types and engine implementations to provide a flexible framework in the diverse DSML scenery. Second, as a concrete but nevertheless generic implementation of a simulation engine for behavior models, we present semantic model specifications and a runtime interfacing to the Ptolemy II tool suite. As a project in the area of model simulation, the latter provides a mature sophisticated and formally grounded backbone for model execution. We present our approach as an open source Eclipse integration to be an extension to the Eclipse modeling projects. After introducing basic concepts, the paper explains how simulations are currently being integrated into the framework and presents some illustrative case studies also covering UML approaches

Executing Domain-Specific Models in Eclipse: KLEPTO - KIELER leveraging Ptolemy

We present a two-level approach to extend the abstract syntax of domain-specific models with concrete semantics in order to execute such models. First, a light-weight execution infrastructure for executable models with a generic user interface allows the tool smith to provide arbitrary execution and visualisation engine implementations for a Domain-Specific Language (DSL). Second, as a concrete but nevertheless generic implementation of a simulation engine for behaviour models, we present semantic model specifications and a runtime interfacing to the Ptolemy II tool suite as a formally founded backbone for model execution. We present our approach as an open source extension to Eclipse modelling projects

Applying Co-Simulation for an Industrial Conveyor System

This paper describes an industrial application of a new research technology enabling the co-simulation of models in continuous time and discrete event respectively. The application concerns modeling of a conveyor system with trolleys that has tilting capabilities that can be used to compensate for high speeds in curves in order to avoid parcels falling of the trolleys. The main challenge for this kind of physical system is that a system solution here requires both insight into the mechanical physics behavior as well as ways in which the system can be controlled discretely by a software based solution. This paper demonstrates how it is possible to bridge the gap between these two different disciplines in co-simulated models

UniTi: Unified composition and time for multi-domain model-based design

To apply model-based design to embedded systems that interface with the physical world, including simulation and verification, current tools fall short. They must provide mathematical (model) definitions that stay close to the specification of the system. They must allow multiple domains, such as the continuous-time, discrete-time and dataflow domain, in a single model including well-defined interaction. They must support model transformations for refining a model during development. And most importantly, they must accurately include and simulate different notions of time in the model. UniTi is a model-based design flow and modelling and simulation environment that delivers on all these aspects. It is based on components that are signal transformations, and therefore mathematical functions. However, in each domain the representation of a signal differs. As components have the same structure in each domain, we can use unified composition operators to represent multiple domains in a single model. Furthermore, this composition provides a unified perspective on time in the domains, even though we differentiate between different notions of time. Time becomes a local property of the model, allowing us to represent and simulate time transformations such as time delays exactly without losing efficiency. Finally, model transformations are defined for such components, which are used for refining and developing the model and which are guided by the design steps in the design flow. We will formally define the domains, composition operators and transformations of UniTi and verify the approach with a case study on a phased array beamforming system

Control and Embedded Computing: Survey of Research Directions

This paper provides a survey of the role of feedback control in embedded realtimesystems, presented in the context of a new EU/IST Network of Excellence, ARTIST2.The survey highlights recent research efforts and future research directions in the areasof codesign of computer-based control systems, implementation-aware embedded controlsystems, and control of real-time computing systems

Introducing Simulation and Model Animation in the MDE Topcased Toolkit

International audienceThe Topcased project aims at developing a modular and generic CASE environment for model driven development of safety critical systems. Model validation is a key feature in this project and model simulation is a major way for validation. The purpose of this paper is to present the current Topcased process for building model simulators and animators. After introducing the functional requirements for model simulation and animation, it is explained how simulation is currently being integrated in the Topcased environment, presenting the main components of a simulator: a model animator, a scenario builder and a simulation engine. The approach is illustrated by the presentation of the first simulation experiment conducted in the project: the UML 2 StateMachines case study