Time filter

Source Type

München, Germany

Vogelsang A.,TU Munich | Femmer H.,TU Munich | Winkler C.,MAN Truck and Bus AG
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

[Context & motivation] Requirements for automotive software systems are predominately documented in natural language and often serve as a basis for the following development process. Therefore, requirements artifact quality is important. Requirements often contain references to specific states of a system, which we call modes (e.g., “While the system is running,...”). [Problem] However, these references are often implicit and therefore, we suspect them as possible source for misunderstandings and ambiguities. [Principal idea] In this paper, we explore the relation between quality defects of natural language requirements and the description of modes within them. For this purpose, we investigate review findings of industrial requirements specifications and assess howmany findings contain issues addressing a mode and which defect types are most affected by mode-related findings. [Contribution] Our preliminary results showthat 46% of all considered review findings contain issues addressing a mode. Defect types in which modes played a major role were completeness and unambiguity. Based on these results, we argue that explicitly specifying modes prior to requirements formulation may increase the artifact quality of natural language requirements specifications. © Springer International Publishing Switzerland 2016.

Propster M.,TU Munich | Marz L.,STREMLER AG | Reinhart G.,TU Munich | Intra C.,MAN Truck and Bus AG
Procedia CIRP | Year: 2015

To stay competitive and reach a high productivity, mixed model assembly lines need to handle variations in capacity requirements induced by the different variants manufactured. Therefore workforce flexibility is required, i. e. drifting, which allows workers to leave their stations to fulfill high equipped variants, and the allocation of jumpers. These support if drifting is not sufficient. This paper presents a simulation tool which simulates these aspects of worker flexibility according to the produced variants and their sequence. Furthermore an approach is introduced which validates line balancing results by using the simulation tool. Since the simulation tool is already in use at a commercial vehicle company, an example of application is also given in this paper. © 2014 The Authors. Published by B.V.

Nourani-Vatani N.,MAN Truck and Bus AG | Lopez-Sastre R.,University of Alcala | Williams S.,University of Sydney
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In this paper we study the challenging problem of seafloor imagery taxonomic categorization. Our contribution is threefold. First, we demonstrate that this task can be elegantly translated into a Structured SVM learning framework. Second, we introduce a taxonomic loss function in the structured output classification objective during learning that is shown to improve the performance over other loss functions. And third, we show how the Structured SVM can naturally deal with the problem of learning from data imbalance by scaling the cost of misclassification during the optimization. We present a thorough experimental evaluation using the challenging and publicly available Tasmania Coral Point Count dataset, where our models drastically outperform the stateof- the-art-results reported. © Springer International Publishing Switzerland 2015.

Bauer F.,University of Federal Defense Munich | Fleischhacker J.,MAN Truck and Bus AG
SAE Technical Papers | Year: 2015

A Hardware-in-the-Loop (HiL) system for Electronic Control Units (ECU) of electro-pneumatic brake systems is presented. The HiL system runs a real-time capable vehicle model comprising of both the vehicle dynamics and the electro-pneumatic brake system. The dynamic behaviour of the vehicle can be simulated either by a real-time multi-body vehicle model or by a simpler system dynamic (double-track) model. To assess the quality of the system dynamic vehicle model, it is compared to a multi-body vehicle model which was validated with comprehensive experimental results. Discrepancies can be seen for highly unsteady manoeuvres. Reasons for these discrepancies caused by the modelling topology of the system dynamic vehicle model are given. In order to simulate the electro-pneumatic brake system, a real-time model has been developed and validated. The different topologies of brake systems can be assembled from components and integrated into the vehicle model. The model of the brake system determines the transient response of brake torques at the wheels as a result of the electrical signals given by the ECU. The HiL system allows the simulation of anti-lock braking manoeuvres as well as manoeuvres that feature interventions of the Electronic Stability Control system (ESC). Using this developed approach, it is possible to estimate the consumption of air during an anti-lock braking manoeuvre or to assess the performance of the ESC during various manoeuvres. In the future, the presented system can support the homologation process of ESC by adjusting the parameters of the system in advance or by a virtual homologation of some of the numerous vehicle variants. © Copyright 2015 SAE International.

Vogelsang A.,TU Munich | Teuchert S.,MAN Truck and Bus AG | Girard J.-F.,MAN Truck and Bus AG
2012 4th International Workshop on Modeling in Software Engineering, MiSE 2012 - Proceedings | Year: 2012

Functional dependencies and feature interactions are a major source of erroneous and unwanted behavior in software-intensive systems. To overcome these problems, many approaches exist that focus on modeling these functional dependencies in advance, i.e., in the specification or the design of a system. However, there is little empirical data on the amount of such interactions between system functions in realistic systems. In this paper, we analyze structural models of a modern realistic automotive vehicle system with the aim to assess the extent and characteristics of interactions between system functions. Our results show that at least 69% of the analyzed system functions depend on each other or influence each other. These dependencies stretch all over the system whereby single system functions have dependencies to up to 40% of all system functions. These results challenge the current development methods and processes that treat system functions more or less as independent units of functionality. © 2012 IEEE.

Discover hidden collaborations