Simulation-Based Testing of Embedded Software in Space Applications

This paper deals with the software-in-the-loop test approach being developed by the consortium project SiLEST (DLR, TU-Berlin, IAV, FhG FIRST, Webdynamix). We present a layer structure of the control loop that allows components of the environment simulation to be used for hardware-in-the-loop and software-in-the-loop testing of embedded systems software. The approach is specifically designed to test software behaviour in disturbed operating conditions, such as in a harsh environment, for example. In space applications, intensive radiation can corrupt computations and stored data. In addition, electronic devices such as sensors age much faster than on earth so that changed sensor deviations must be expected. Much the same is true of numerous other embedded systems, e.g. in automotive applications. Here, too, the electronic components are exposed to extreme conditions (temperature) and are subject to ageing processes

The Architecture of the Smile/M Simulation Environment

Smile is an object-oriented, equation-based, hybrid modeling and simulation environment. The focus of this paper is the extension (Smile/M) of the Smile system to Modelica, a new modeling language currently being defined in an international collaboration effort. An overview of this language, which may well become a quasi-standard in the simulation community, is given. Interfacing Smile to Modelica will enhance the interoperability of the system and allow the reuse of models developed in other environments

Specification of Software Controlling a Discrete-Continuous Environment

In this paper, we present an object-oriented approach to the specification of discrete software controllers that are embedded in discrete-continuous (or hybrid) environments. The structure of the controller and its environment is specified using object notations extended to include continuous and hybrid objects. Control behavior is specified with state automata and pre/postconditions using the statechart notation and constructive Z-schemata. The behavior of the environment is specified with systems of differential equations using an object-oriented extension of Z for the specification of hybrid systems. We use a case study on control of a high-pressure steam boiler to illustrate how the environment structure can help to design the controller and how environment simulation can be used to derive control parameters. Keywords Embedded systems, discrete-continuous systems, object-oriented specification. INTRODUCTION Today powerful tools supporting specification, analysis and simulation ..

Formalization of Algebraic Specification in the Development Language Deva

. We show how software development based on algebraic specification can formally be represented in the development language Deva. We have formalized essential parts of the algebraic specification language Spectrum and a semantic development relation. The use of such a representation is three-fold: It makes developments amenable to consistency checks by machine, it documents the development for human readers, and it makes explicit the correspondence of development steps and resulting proof obligations. 1 Introduction Formal software development necessitates generation and verification of large numbers of proofs. These proofs on one hand fulfill a similar role as proofs in mathematics: they provide insight and convince human readers of the correctness of the stated result. On the other hand, the number and technical nature of the proofs necessitate mechanical verification. Thus it is necessary to bridge the gap between detailed, machine-checkable, formal proofs and concise, readable, i..