A Problem-Oriented Approach for Dynamic Verification of Heterogeneous Embedded Systems

This work presents a virtual prototyping methodology for the design and verification of industrial devices in the field level of industrial automation systems. This work demonstrates that virtual prototypes can help increase the confidence in the correctness of a design thanks to a deeper understanding of the complex interactions between hardware, software, analog and mixed-signal components of embedded systems and the physical processes they interact with

Modeling Cyber-Physical Production Systems with SystemC-AMS

The heterogeneous nature of SystemC-AMS makes it a perfect candidate solution to support Cyber-Physical Production Systems (CPPSs), i.e., systems that are characterized by a tight interaction of the cyber part with the surrounding physical world and with manufacturing production processes. Nonetheless, the support for the modeling of physical and mechanical dynamics typical of production machinery goes far beyond the initial application scenario of SystemC-AMS, thus limiting its effectiveness and adoption in the production and manufacturing context. This paper starts with an analysis of the current adoption of SystemC-AMS to highlight the open points that still limit its effectiveness, with the goal of pinpointing current issues and to propose solutions that could improve its effectiveness, and make SystemC-AMS an essential resource also in the new Industry 4.0 scenario

Principes et réalisation d'une interface de synchronisation interopérable entre modèles de calcul SystemC AMS pour le prototypage virtuel optimisé de systèmes multi-disciplines

The design of embedded systems is currently an increasingly complex problem. These systems tend to become heterogeneous in the sense that they require the integration of components described by means of different physical/engineering disciplines, for example, electrical, optical, thermal, mechanical, chemical, or biological. Besides, these disciplines can be described under different time domains, for example, Discrete Event (DE), Discrete Time (DT), or Continuous Time (CT). To address this problem, designers require modeling and simulation tools to describe the system’s components under different time domains and synchronize them in the same simulation environment. We explore the possibilities of modeling, simulating and synchronizing multi-disciplinary systems in the same environment, using as reference the SystemC Analog/Mixed-Signal (AMS) simulation standard. We analyze the method introduced in SystemC AMS for synchronizing the DE and DT domains, and we identify its drawbacks. Besides, we introduce a new formalization of the synchronization problem, which is used to detect issues in a model before simulation. We propose a simulator prototype called SystemC Multi-Disciplinary Virtual Prototyping (MDVP), which is implemented as an extension of SystemC. It allows the modeling, and the generic hierarchical elaboration and simulation of multi-disciplinary systems, by means of different Models of Computation (MoCs). To build the MDVP simulator, we introduce a synchronization principle to handle interactions between MoCs. In addition, we introduce a methodology to add, in the simulator prototype, MoCs described under different time domains. We apply this methodology to add a Timed Data Flow MoC in SystemC MDVP. This MoC implements the DT semantics introduced by the SystemC AMS standard, and is based on the synchronization principle between the DE and DT domains. Using the TDF MoC, we implement and simulate a case study of a vibration sensor model and its digital front end circuit. This case study includes a feedback loop and several interactions between the DE and DT domains.La conception de systèmes embarqués devient de plus en plus complexe. Ces systèmes sont hétérogènes dans le sens où ils nécessitent l’intégration de composants décrits au moyen de plusieurs disciplines scientifiques, par exemple, l’électricité, l’optique, la thermique, la mécanique, la chimie ou la biologie. De plus, ces disciplines peuvent être représentées dans des domaines temporels différents, par exemple, le domaine des événements discrets, celui du temps discret, ou celui du temps continu. Face à cette situation, les concepteurs ont besoin d’outils de modélisation et de simulation efficaces pour décrire le comportement d’un système hétérogène dans un environnement de simulation unique. Nous examinons la possibilité de modéliser, de simuler et de synchroniser les systèmes multi-disciplines dans le même environnement, en utilisant comme référence la norme de simulation « SystemC Analog/Mixed-Signal (AMS) ». Nous analysons la méthode introduite par SystemC AMS pour synchroniser le domaine des événements discrets avec celui du temps discret, et nous identifions ses inconvénients. Nous proposons une formalisation du problème de synchronisation qui permet de détecter les problèmes existants dans un modèle avant la simulation. Nous proposons un prototype de simulateur appelé « SystemC Multi-Disciplinary Virtual Prototyping (MDVP) », qui est implémenté comme une extension de SystemC. Il permet la modélisation, l’élaboration, et la simulation hiérarchique de systèmes multi-disciplines au moyen de plusieurs modèles de calcul. Pour concevoir le simulateur MDVP, nous introduisons un nouveau principe de synchronisation entre plusieurs modèles de calcul. En outre, nous introduisons une méthodologie pour ajouter, dans le prototype de simulateur, des modèles de calcul représentés par plusieurs domaines temporels. Nous appliquons cette méthodologie pour ajouter un modèle de calcul « Timed Data Flow (TDF) » dans SystemC MDVP. Ce modèle de calcul repose sur la sémantique du temps discret introduite par SystemC AMS, et sur la formalisation du principe de synchronisation entre le domaine des événements discrets et celui du temps discret. Nous mettons en œuvre le modèle de calcul TDF, dans le cas d’un capteur de vibrations et son circuit numérique. Ce modèle comporte une boucle d’asservissement et plusieurs interactions entre le domaine des événements discrets et celui du temps discret

Bridging MoCs in SystemC specifications of heterogeneous systems

In order to get an efficient specification and simulation of a heterogeneous system, the choice of an appropriate model of computation (MoC) for each system part is essential. The choice depends on the design domain (e.g., analogue or digital), and the suitable abstraction level used to specify and analyse the aspects considered to be important in each system part. In practice, MoC choice is implicitly made by selecting a suitable language and a simulation tool for each system part. This approach requires the connection of different languages and simulation tools when the specification and simulation of the system are considered as a whole. SystemC is able to support a more unified specification methodology and simulation environment for heterogeneous system, since it is extensible by libraries that support additional MoCs. A major requisite of these libraries is to provide means to connect system parts which are specified using different MoCs. However, these connection means usually do not provide enough flexibility to select and tune the right conversion semantic in amixed-level specification, simulation, and refinement process. In this article, converter channels, a flexible approach for MoC connection within a SystemC environment consisting of three extensions, namely, SystemC-AMS, HetSC, and OSSS+R, are presented.This work is supported by the FP6-2005-IST-5 European project

SystemC-AMS Simulation of Energy Management of Electric Vehicles

Electric vehicles (EV) are rapidly invading the market, since they are clean, quiet and energy efficient. However, there are many factors that discourage EVs for current and potential customers. Among them, driving range is one of the most critical issues: running out of battery charge while driving results in serious inconvenience even comparable to vehicle breakdown, as an effect of long fuel recharging times and lack of charging facilities. As a result, the dimensioning of the energy subsystem of an EV is a crucial activity. The choice of the power components and of the adopted policies should thus be validated at design time through simulations, that estimate the vehicle driving range under reference driving profiles. It is thus necessary to build a simulation framework that takes into account an EV power consumption model, dependent on the characteristics of the vehicle and of the driving route, plus accurate models for all power components, including batteries and green power sources. The goal of this paper is to achieve early EV simulation, so that the designer can estimate at design time the driving range of the vehicle, validate the adopted components and policies and evaluate alternative configurations

A Holistic Approach to Functional Safety for Networked Cyber-Physical Systems

Functional safety is a significant concern in today's networked cyber-physical systems such as connected machines, autonomous vehicles, and intelligent environments. Simulation is a well-known methodology for the assessment of functional safety. Simulation models of networked cyber-physical systems are very heterogeneous relying on digital hardware, analog hardware, and network domains. Current functional safety assessment is mainly focused on digital hardware failures while minor attention is devoted to analog hardware and not at all to the interconnecting network. In this work we believe that in networked cyber-physical systems, the dependability must be verified not only for the nodes in isolation but also by taking into account their interaction through the communication channel. For this reason, this work proposes a holistic methodology for simulation-based safety assessment in which safety mechanisms are tested in a simulation environment reproducing the high-level behavior of digital hardware, analog hardware, and network communication. The methodology relies on three main automatic processes: 1) abstraction of analog models to transform them into system-level descriptions, 2) synthesis of network infrastructures to combine multiple cyber-physical systems, and 3) multi-domain fault injection in digital, analog, and network. Ultimately, the flow produces a homogeneous optimized description written in C++ for fast and reliable simulation which can have many applications. The focus of this thesis is performing extensive fault simulation and evaluating different functional safety metrics, \eg, fault and diagnostic coverage of all the safety mechanisms

CONTREX: Design of embedded mixed-criticality CONTRol systems under consideration of EXtra-functional properties

The increasing processing power of today’s HW/SW platforms leads to the integration of more and more functions in a single device. Additional design challenges arise when these functions share computing resources and belong to different criticality levels. The paper presents the CONTREX European project and its preliminary results. CONTREX complements current activities in the area of predictable computing platforms and segregation mechanisms with techniques to consider the extra-functional properties, i.e., timing constraints, power, and temperature. CONTREX enables energy efficient and cost aware design through analysis and optimization of these properties with regard to application demands at different criticality levels