Johannes Richenhagen

PERSIST – A scalable software architecture for the control of diverse automotive hybrid topologies

Software development for modern powertrains requires the handling of increasing functional complexity at shorter development cycles and a high quality level. Hybrid vehicles are especially affected since multiple components and functions need to interact. Appropriate software architectures is the core lever to ease software reuse and ensure quality already during the specification phase. This article presents an approach where hybrid control software functions are developed inside an architecture framework with consistent design guidelines based on a quality model, a methodology how to derive the architecture from required control features and finally a verification and validation strategy to ensure quality already on architecture level. Also, concrete figures will be shown for a series development project.

Metrics-based strategies for quality assurance of automotive embedded software

Feature complexity in modern vehicles is continuously rising, requiring significant additional effort to assure the quality of the embedded software. An efficient and effective quality assurance strategy is central for deployment of a successful software product. However, test strategy decisions are usually made experience-based with poor documentation and scalability to large development teams. Hence, we propose to use the testers experience for quantifying quality characteristics as well as the impact of different tests and resulting bug fixes on the same. Then, optimization algorithms can be applied to derive a nearly optimal test strategy. This leads to an approach where test strategy decisions are transparent, scalable to different users and conserve testing experience. This paper takes the first step by examining the impact of strategical decisions on the resulting software quality. Quantification takes place using adequate software metrics. The impact of the quality assurance strategy on product quality is identified based on data of several industry projects using statistical procedures.

Metrics for Verification and Validation of Architecture in Powertrain Software Development

The key challenges to software development in the powertrain domain are an exploding complexity, short development cycles and increasing quality and safety requirements. Architecture design addresses these challenges by structuring development over the entire lifecycle. Being a work product of the very early stage of development, architecture design errors lead to rework and higher development costs at any following development step. Verification and validation on architecture level leads to significant quality increase and reduces development risks. To approach this in a structured manner, the authors propose automated metric based evaluation of the software architecture. Metrics are identified and developed based on the Goal Question Metric approach. Quality goals for the architecture are derived from international standards, organizational goals and domain specific requirements. Questions are developed based on the goals to derive metrics for the evaluation of software quality criteria. The metrics developed are integrated into the software development process. At the end, application examples from series hybrid control software projects are shown. By the automated, metric-based approach so far extensive manual reviews and scenario analyses are supported by objective and measurable criteria. As an added value to state-of-the-art development strategies, frontloading of the costs is achieved by early evaluation of the software architecture.

Mastering the future: Agile model-based system design for BMW’s electrified next generation platform

Future mobility systems are becoming more complex. Existing processes for hardware component oriented development reach a limit for highly integrated systems. High quality cannot be efficiently ensured any longer at shorter development cycles and reduced budgets.

Automated continuous evaluation of AUTOSAR software architecture for complex powertrain systems

Connectivity of the vehicle to heterogeneous information sources is one of the key factors which lead to complexity of automotive software architecture. The information content from external communication sources modifies the structure, content and the synchronization of control algorithms. In addition to this, time and cost constraints for software development are challenging. With increasing complexity and reduction of development time, ensuring software quality is one of the foremost priorities of vehicle manufacturers. Software architecture plays an important role in ensuring quality by implementing design principles which enhance non-functional quality attributes of the automotive software. The extent to which a software architecture definition fulfills the quality requirements is not verified at early stages of development. As a consequence, design problems are transferred to later stages of development thereby causing rework of software artifacts. The paper focuses on a tool-based evaluation of non-functional quality characteristics using the concept of Continuous Integration for AUTOSAR-based transmission control software. The suggested approach enables early and continuous evaluation of software architecture thereby improving software quality

Biofuels for Combustion Engines

The requirements on the development of combustion engines have dramatically changed in the past decade. This includes strict emission laws, CO2 emission reduction, different propulsion concepts including powertrain electrification and a reduced time to market with an increased number of engine variants. One alternative to mitigate both the need for fossil burnings and the CO2 emission reduction is the use of alternative fuels from biomass. Thus, different legislation authorities aim for higher proportions of alternative fuels on the market. However, this strategy involves changes on different development domains for combustion engines. This paper presents ongoing research taking place within the interdisciplinary activities at the Institute for Combustion Engines. The effects on the control system as one enabler of further investigations are presented from the perspective of variant management and complexity handling. Proceedings of the research on innovative control algorithms for fuel adaption are outlined. At third, we discuss the impact of direct injection of alternative fuels on liner wetting and piston ring development. At last, the combustion of fuels from biomass with regards to the emissions formation is investigated from two points of view: for gasoline combustion methods, the characteristics of gaseous emission are presented. For Diesel combustion, we show the different formation of particles by applying diverse measurement methods.