arXiv subjects

Christian Berger

Publications and source records attributed to Christian Berger.

86 records · Page 5Linked to original sources

arXiv2015

Simulations on Consumer Tests: Systematic Evaluation of Tolerance Ranges by Model-Based Generation of Simulation Scenarios

Context: Since 2014 several modern cars were rated regarding the performances of their active safety systems at the European New Car Assessment Programme (EuroNCAP). Nowadays, consumer tests play a significant role for the OEM's series development with worldwide perspective, because a top rating is needed to underline the worthiness of active safety features from the customers' point of view. Furthermore, EuroNCAP already published their roadmap 2020 in which they outline further extensions in today's testing and rating procedures that will aggravate the current requirements addressed to those systems. Especially Autonomous Emergency Braking/Forward Collision Warning systems (AEB/FCW) are going to face a broader field of application as pedestrian detection or two-way traffic scenarios. Objective: This work focuses on the systematic generation of test scenarios concentrating on specific parameters that can vary within certain tolerance ranges like the lateral position of the vehicle-under-test (VUT) and its test velocity for example. It is of high interest to examine the effect of the tolerance ranges on the braking points in different test cases representing different trajectories and velocities because they will influence significantly a later scoring during the assessments and thus the safety abilities of the regarding car. Method: We present a formal model using a graph to represent the allowed variances based on the relevant points in time. Now, varying velocities of the VUT will be added to the model while the vehicle is approaching a target vehicle. The derived trajectories were used as test cases for a simulation environment. Selecting interesting test cases and processing them with the simulation environment, the influence on the system's performance of different test parameters will be investigated.

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arXiv2014

Softwaretechnische Absicherung intelligenter Systeme im Fahrzeug

"This article describes software engineering techniques to be used in order to ensure the necessary quality of intelligent and therefore massive software-based systems in vehicles. Quality assurance for intelligent software is achieved through a bundle of modern software engineering methods. Architecture and design patterns for securing the software components are supplemented by test concepts and frameworks for validation and checks of robustness of the implementation. These patterns describe established and therefore consolidated solutions for certain problems as for instance reliability or efficient execution. -- Dieser Artikel skizziert, welche Software-Entwurfstechniken heute zum Einsatz kommen können, um intelligente, Software-lastige Systeme im Fahrzeug abzusichern. Dabei spielt zunächst das Qualitätsmanagement durch Software-technische Maßnahmen eine zentrale Rolle. Architektur- und Entwurfmuster für die Software-technische Absicherung von Komponenten werden ergänzt um Test-Konzepte zur Validierung von Spezifikationen und der Robustheit der Implementierung. Architekturen und Entwurfs-Muster beschreiben erprobte und damit konsolidierte Lösungen für bestimmte Problemklassen wie etwa Zuverlässigkeit oder effiziente Ausführung.

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arXiv2014

Engineering Autonomous Driving Software

A larger number of people with heterogeneous knowledge and skills running a project together needs an adaptable, target, and skill-specific engineering process. This especially holds for a project to develop a highly innovative, autonomously driving vehicle to participate in the 2007 DARPA Urban Challenge. In this contribution, we present essential elements of a software and systems engineering process to develop a so-called artificial intelligence capable of driving autonomously in complex urban situations. The process itself includes agile concepts, like a test first approach, continuous integration of all software modules, and a reliable release and configuration management assisted by software tools in integrated development environments. However, one of the most important elements for an efficient and stringent development is the ability to efficiently test the behavior of the developed system in a flexible and modular system simulation for urban situations both interactively and unattendedly. We call this the simulate first approach.

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arXiv2014

Product Line Metrics for Legacy Software in Practice

Nowadays, customer products like vehicles do not only contain mechanical parts but also a highly complex software and their manufacturers have to offer many variants of technically very similar systems with sometimes only small differences in their behavior. The proper reuse of software artifacts which realize this behavior using a software product line is discussed in recent literature and appropriate methods and techniques for their management are proposed. However, establishing a software product line for integrating already existing legacy software to reuse valuable resources for future similar products is very company-specific. In this paper, a method is outlined for evaluating objectively a legacy software's potential to create a software product line. This method is applied to several development projects at Volkswagen AG Business Unit Braunschweig to evaluate the software product line potential for steering systems.

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arXiv2014

Measuring the Ability to Form a Product Line from Existing Products

A product line approach can save valuable resources by reusing artifacts. Especially for software artifacts, the reuse of existing components is highly desirable. In recent literature, the creation of software product lines is mainly proposed from a top-down point of view regarding features which are visible by customers. In practice, however, the design for a product line often arises from one or few existing products that descend from a very first product starting with copy-paste and evolving individually. In this contribution, we propose the theoretical basis to derive a set of metrics for evaluating similar software products in an objective manner. These metrics are used to evaluate the set of product's ability to form a product line.

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arXiv2014

Caroline: An Autonomously Driving Vehicle for Urban Environments

The 2007 DARPA Urban Challenge afforded the golden opportunity for the Technische Universität Braunschweig to demonstrate its abilities to develop an autonomously driving vehicle to compete with the world's best competitors. After several stages of qualification, our team CarOLO qualified early for the DARPA Urban Challenge Final Event and was among only eleven teams from initially 89 competitors to compete in the final. We had the ability to work together in a large group of experts, each contributing his expertise in his discipline, and significant organisational, financial and technical support by local sponsors who helped us to become the best non-US team. In this report, we describe the 2007 DARPA Urban Challenge, our contribution "Caroline", the technology and algorithms along with her performance in the DARPA Urban Challenge Final Event on November 3, 2007.

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arXiv2014

Software & Systems Engineering Process and Tools for the Development of Autonomous Driving Intelligence

When a large number of people with heterogeneous knowledge and skills run a project together, it is important to use a sensible engineering process. This especially holds for a project building an intelligent autonomously driving car to participate in the 2007 DARPA Urban Challenge. In this article, we present essential elements of a software and system engineering process for the development of artificial intelligence capable of driving autonomously in complex urban situations. The process includes agile concepts, like test first approach, continuous integration of every software module and a reliable release and configuration management assisted by software tools in integrated development environments. However, the most important ingredients for an efficient and stringent development are the ability to efficiently test the behavior of the developed system in a flexible and modular simulator for urban situations.

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arXiv2014

Rapid Integration and Calibration of New Sensors Using the Berkeley Aachen Robotics Toolkit (BART)

After the three DARPA Grand Challenge contests many groups around the world have continued to actively research and work toward an autonomous vehicle capable of accomplishing a mission in a given context (e.g. desert, city) while following a set of prescribed rules, but none has been completely successful in uncontrolled environments, a task that many people trivially fulfill every day. We believe that, together with improving the sensors used in cars and the artificial intelligence algorithms used to process the information, the community should focus on the systems engineering aspects of the problem, i.e. the limitations of the car (in terms of space, power, or heat dissipation) and the limitations of the software development cycle. This paper explores these issues and our experiences overcoming them.

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arXiv2014

Extensible Validation Framework for DSLs using MontiCore on the Example of Coding Guidelines

Unit test environments are today's state of the art for many programming languages to keep the software's quality above a certain level. However, the software's syntactic quality necessary for the developers themselves is not covered by the aforementioned frameworks. This paper presents a tool realized using the DSL framework MontiCore for automatically validating easily extensible coding guidelines for any domain specific language or even general purpose languages like C++ and its application in an automotive R&D project where a German OEM and several suppliers were involved. Moreover, it was exemplary applied on UML/P-based sequence charts as well.

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arXiv2014

ProcDSL + ProcEd - a Web-based Editing Solution for Domain Specific Process-Engineering

In a high-tech country products are becoming rapidly more complex. To manage the development process as well as to encounter unforeseen challenges, the understanding and thus the explicit modeling of organizational workflows is more important than ever. However, available tools to support this work, in most cases force a new notation upon the company or cannot be adapted to a given publication layout in a reasonable amount of time. Additionally, collaboration among colleagues as well as different business units is complicated and less supported. Since it is of vital importance for a company to be able to change its processes fast and adapt itself to new market situations, the need for tools supporting this evolution is equally crucial. In this paper we present a domain specific language (DSL) developed for modeling a company's workflows. Furthermore, the DSL is embedded in a web-based editor providing transparent access using modern web 2.0 technologies. Results of the DSL's as well as the editor's application to document, model, and improve selected workflows of a German automotive manufacturer are presented.

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arXiv2014

Autonomous Driving - 5 Years after the Urban Challenge: The Anticipatory Vehicle as a Cyber-Physical System

In November 2007 the international competition DARPA Urban Challenge took place on the former George Airforce Base in Victorville, California to significantly promote the research and development on autonomously driving vehicles for urban environments. In the final race only eleven out of initially 89 competitors participated and "Boss" from Carnegie Mellon University succeeded. This paper summarizes results of the research carried out by all finalists within the last five years after the competition and provides an outlook where further investigation especially for software engineering is now necessary to achieve the goal of driving safely and reliably through urban environments with an anticipatory vehicle for the mass-market.

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arXiv2014

Meta-Metrics for Simulations in Software Engineering on the Example of Integral Safety Systems

Vehicles passengers and other traffic participants are protected more and more by integral safety systems. They continuously perceive the vehicles environment to prevent dangerous situations by e.g. emergency braking systems. Furthermore, increasingly intelligent vehicle functions are still of major interest in research and development to reduce the risk of accidents. However, the development and testing of these functions should not rely only on validations on proving grounds and on long-term test-runs in real traffic; instead, they should be extended by virtual testing approaches to model potentially dangerous situations or to re-run specific traffic situations easily. This article outlines meta-metrics as one of todays challenges for the software engineering of these cyber-physical systems to provide guidance during the system development: For example, unstable results of simulation test-runs over the vehicle functions revision history are elaborated as an indicating metric where to focus on with real or further virtual test-runs; furthermore, varying acting time points for the same virtual traffic situation are indicating problems with the reliability to interpret the specific situation. In this article, several of such meta-metrics are discussed and assigned both to different phases during the series development and to different levels of detailedness of virtual testing approaches.

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arXiv2014

From a Competition for Self-Driving Miniature Cars to a Standardized Experimental Platform: Concept, Models, Architecture, and Evaluation

Context: Competitions for self-driving cars facilitated the development and research in the domain of autonomous vehicles towards potential solutions for the future mobility. Objective: Miniature vehicles can bridge the gap between simulation-based evaluations of algorithms relying on simplified models, and those time-consuming vehicle tests on real-scale proving grounds. Method: This article combines findings from a systematic literature review, an in-depth analysis of results and technical concepts from contestants in a competition for self-driving miniature cars, and experiences of participating in the 2013 competition for self-driving cars. Results: A simulation-based development platform for real-scale vehicles has been adapted to support the development of a self-driving miniature car. Furthermore, a standardized platform was designed and realized to enable research and experiments in the context of future mobility solutions. Conclusion: A clear separation between algorithm conceptualization and validation in a model-based simulation environment enabled efficient and riskless experiments and validation. The design of a reusable, low-cost, and energy-efficient hardware architecture utilizing a standardized software/hardware interface enables experiments, which would otherwise require resources like a large real-scale test track.

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arXiv2014

Engineering the Hardware/Software Interface for Robotic Platforms - A Comparison of Applied Model Checking with Prolog and Alloy

Robotic platforms serve different use cases ranging from experiments for prototyping assistive applications up to embedded systems for realizing cyber-physical systems in various domains. We are using 1:10 scale miniature vehicles as a robotic platform to conduct research in the domain of self-driving cars and collaborative vehicle fleets. Thus, experiments with different sensors like e.g.~ultra-sonic, infrared, and rotary encoders need to be prepared and realized using our vehicle platform. For each setup, we need to configure the hardware/software interface board to handle all sensors and actors. Therefore, we need to find a specific configuration setting for each pin of the interface board that can handle our current hardware setup but which is also flexible enough to support further sensors or actors for future use cases. In this paper, we show how to model the domain of the configuration space for a hardware/software interface board to enable model checking for solving the tasks of finding any, all, and the best possible pin configuration. We present results from a formal experiment applying the declarative languages Alloy and Prolog to guide the process of engineering the hardware/software interface for robotic platforms on the example of a configuration complexity up to ten pins resulting in a configuration space greater than 14.5 million possibilities. Our results show that our domain model in Alloy performs better compared to Prolog to find feasible solutions for larger configurations with an average time of 0.58s. To find the best solution, our model for Prolog performs better taking only 1.38s for the largest desired configuration; however, this important use case is currently not covered by the existing tools for the hardware used as an example in this article.

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