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Schwarzl C.,Virtual Vehicle | Aichernig B.K.,University of Graz | Wotawa F.,University of Graz
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

The fast growth in complexity of embedded and software enabled systems requires for automated testing strategies to achieve a high system quality. This raise of complexity is often caused by the distribution of functionality over multiple control units and their connection via a network. We define an extended symbolic transition system (ESTS) and their compositional semantics to reflect these new requirements imposed on the test generation methods. The introduced ESTS incorporates timed behavior by transition execution times and delay transitions. Their timeout can be defined either by a constant value or an attribute valuation. Moreover we introduce a communication scheme used to specify the compositional behavior and define a conformance relation based on alternating simulation. Furthermore we use the conformance relation as the basis for a simple random test generation technique to verify the applicability of the presented approach. This formal framework builds the foundation of our UML test case generator. © 2011 IFIP International Federation for Information Processing. Source


Polzlbauer F.,Virtual Vehicle | Bate I.,University of York | Brenner E.,University of Graz
Studies in Computational Intelligence | Year: 2014

Automotive applications can be described as distributed embedded software which perform real-time computation on top of a heterogeneous hardware platform. One key phase in designing distributed software systems is software deployment. Therein it is decided how software components are deployed over the hardware platform, and how the communication between software components is performed. These decisions significantly determine the system performance. This chapter tackles the software deployment problem, tailored to the needs of the automotive domain. Thereby, the focus is on two issues: the configuration of the communication infrastructure and how to handle design constraints. It is shown, how state-of-the-art approaches have to be extended in order to tackle these issues, and how the overall process can be performed efficiently, by utilizing search methodologies. © 2014 Springer-Verlag Berlin Heidelberg. Source


Kitanoski F.,Virtual Vehicle | Hofer A.,University of Graz
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2010

Hybrid electric vehicles are regarded as a possible solution for the reduction of pollutant emissions and for improving the fuel economy. Besides the conventional cooling circuit for the engine, hybrid vehicles need cooling for the electrical drives and for the energy storage systems as well. The development of appropriate cooling systems has the consequence that the number of auxiliary components involved, the weight and above all the energy consumption is increased. Therefore in order to minimize the energy consumption an optimal strategy for the operation of the cooling aggregates is required. In this paper an approach for finding the optimal control strategy of the electric auxiliaries over an apriori defined driving cycle is introduced. An energy minimization problem with constraints given by the maximum allowed temperature of the components is stated. This problem is based on a nonlinear mathematical model of the cooling system. It is shown how the nonlinear continuous time model can be equivalently replaced by a suitable linear discrete time model where some of the variables are confined to take integer values. This allows us to cast the optimization problem as a mixed integer linear program. The proposed approach is demonstrated by an example. For this purpose a cooling system is considered where an electrically driven water pump and an electric cooling fan are involved. As a result the optimal interaction of the water pump and the fan is computed such that the energy consumption of these components is minimized subject to given temperature constraints. © 2010 IFAC. Source


Polzlbauer F.,Virtual Vehicle | Bate I.,University of York | Brenner E.,University of Graz
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

In modern embedded systems, e.g. avionics and automotive, it is not unusual for there to be between 40 and 100 processors with a great deal of the software having hard real-time requirements and constraints over how, when and where they execute. The requirements and constraints are essential to the overall systems dependability and safety (e.g. to ensure replicas execute on different hardware). This leads to a complex design space exploration (DSE) problem which cannot be practically solved manually especially if the schedule is to be maintained. In this paper it is shown that dealing with the constraints using a conventional state of the art "System Configuration Algorithm" is less efficient, less effective and does not scale well. This issue can be improved by performing constraint pre-processing as well as constraint encoding. It is shown that our approach can handle typical industrial requirements that come from the automotive industry's AUTOSAR standard in an efficient way. © 2012 Springer-Verlag. Source


Felbinger H.,Virtual Vehicle | Wotawa F.,Graz University of Technology | Nica M.,AVL List GmbH
Proceedings - 11th International Workshop on Automation of Software Test, AST 2016 | Year: 2016

In this paper we investigate a method for test suite evaluation that is based on an inferred model from the test suite. The idea is to use the similarity between the inferred model and the system under test as a measure of test suite adequacy, which is the ability of a test suite to expose errors in the system under test. We define similarity using the root mean squared error computed from the differences of the system under test output and the model output for certain inputs not used for model inference. In the paper we introduce the approach and provide results of an experimental evaluation where we compare the similarity with the mutation score. We used the Pearson Correlation coefficient to calculate whether a linear correlation between mutation score and root mean squared error exists. As a result we obtain that in certain cases the computed similarity strongly correlates with the mutation score. © 2016 ACM. Source

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