ClaferMPS: Modeling and Optimizing Automotive Electric/Electronic Architectures Using Domain-Specific Languages

Modern automotive electric/electronic (E/E) architectures are growing to the point where architects can no longer manually predict the effects of their design decisions. Thus, in addition to applying an architecture reference model to decompose their architectures, they also require tools for synthesizing and evaluating candidate architectures during the design process. Clafer is a modeling language, which has been used to model variable multi-layer, multi-perspective automotive system architectures according to an architecture reference model. Clafer tools allow architects to synthesize optimal candidates and evaluate effects of their design decisions. However, since Clafer is a general-purpose structural modeling language, it does not help the architects in building models conforming to the given architecture reference model. In this work, we present ClaferMPS, a set of extensible languages and IDE for modeling E/E architectures using Clafer. First, we present an E/E architecture domain-specific language (DSL) built on top of Clafer, which embodies the reference model and which guides the architects in correctly applying the reference model. We then evaluate the DSL and its implementation by modeling two existing automotive systems, which were originally modeled in plain Clafer. The evaluation showed that by using the DSL, an evaluator obtained correct models by construction because the DSL helped prevent typical errors that are easy to make in plain Clafer. The evaluator was also able to synthesize and evaluate candidate architectures as with plain Clafer. Finally, we demonstrate extensibility capabilities of ClaferMPS. Our implementation is built on top of the JetBrains Meta Programming System, which supports language modularization and composition, multi-stage transformations and projectional editing. As a result, ClaferMPS allows third parties to seamlessly add extensions to both Clafer and the E/E architecture DSL without invasive changes. To illustrate this approach, we consider the Robot Operating System (ROS) communications infrastructure, a case study, which is outside the scope of the existing reference model. We show how the E/E architecture DSL can be adapted to the new domain using MPS language modularization and composition

Synthesis and Exploration of Multi-Level, Multi-Perspective Architectures of Automotive Embedded System

In industry, evaluating candidate architectures of automotive embedded systems is routinely done during the design process. Today's engineers, however, are limited in the number of candidates that they are able to evaluate in order to find the optimal architectures. This limitation results from the difficulty in defining the candidates as it is a mostly manual process. In this work, we propose a way to synthesize multi-level, multi-perspective candidate architectures and to explore them across the different layers and perspectives. Using a reference model similar to the EAST-ADL domain model but with a focus on early design, we explore the candidate architectures for two case studies: an automotive power window system and the central door locking system. Further, we provide a comprehensive set of questions, based on the different layers and perspectives, that engineers can ask to synthesize only the candidates relevant to their task at hand. Finally, using the modeling language Clafer, which is supported by automated backend reasoners, we show that it is possible to synthesize and explore optimal candidate architectures for two highly configurable automotive subsystems

Geometric-based Optimization Algorithms for Cable Routing and Branching in Cluttered Environments

The need for designing lighter and more compact systems often leaves limited space for planning routes for the connectors that enable interactions among the system’s components. Finding optimal routes for these connectors in a densely populated environment left behind at the detail design stage has been a challenging problem for decades. A variety of deterministic as well as heuristic methods has been developed to address different instances of this problem. While the focus of the deterministic methods is primarily on the optimality of the final solution, the heuristics offer acceptable solutions, especially for such problems, in a reasonable amount of time without guaranteeing to find optimal solutions. This study is an attempt to furthering the efforts in deterministic optimization methods to tackle the routing problem in two and three dimensions by focusing on the optimality of final solutions. The objective of this research is twofold. First, a mathematical framework is proposed for the optimization of the layout of wiring connectors in planar cluttered environments. The problem looks at finding the optimal tree network that spans multiple components to be connected with the aim of minimizing the overall length of the connectors while maximizing their common length (for maintainability and traceability of connectors). The optimization problem is formulated as a bi-objective problem and two solution methods are proposed: (1) to solve for the optimal locations of a known number of breakouts (where the connectors branch out) using mixed-binary optimization and visibility notion and (2) to find the minimum length tree that spans multiple components of the system and generates the optimal layout using the previously-developed convex hull based routing. The computational performance of these methods in solving a variety of problems is further evaluated. Second, the problem of finding the shortest route connecting two given nodes in a 3D cluttered environment is considered and addressed through deterministically generating a graphical representation of the collision-free space and searching for the shortest path on the found graph. The method is tested on sample workspaces with scattered convex polyhedra and its computational performance is evaluated. The work demonstrates the NP-hardness aspect of the problem which becomes quickly intractable as added components or increase in facets are considered

Modellbasierte Analyse und Diagnose von Lichtbogenfehlern in 48 V Kfz-Bordnetzen

Zur Untersuchung der Beschaffenheit von Lichtbogenfehlern in 48 V Kfz-Bordnetzen und für die Simulation der elektrischen, und gegebenenfalls funktionalen, Auswirkungen wird in dieser Arbeit ein neues Lichtbogenmodell entworfen, welches die in dieser Arbeit analysierten und definierten Anforderungen an Lichtbogenmodelle für Simulationen in 48 V Kfz-Bordnetzen erfüllen kann. Dieses Lichtbogenmodell kann mit Modellen von Bordnetzen kombiniert und so für die Analyse von fehlerhaften Bordnetzen verwendet werden. Anhand einer exemplarischen Bordnetzauslegung wird demonstriert, dass bei geschickter Wahl der Bordnetzabschlüsse und Verkabelungselemente eine intrinsische Sicherheit gegen serielle Lichtbögen erreicht werden kann. Für parallele Lichtbögen wird ein Diagnoseverfahren vorgestellt, welches in der Lage ist, diese zu detektieren und zu klassifizieren. Es werden für verschiedene Konfigurationen Worstcase-Abschätzungen bezüglich der Verlustenergie und somit der maximalen Reaktionszeit von Diagnoseverfahren durchgeführt. Das modellbasierte Diagnoseverfahren wird abschließend zunächst theoretisch hergeleitet und an einem konkreten Beispiel im Labor und mittels einer mit dem neuen Lichtbogenmodell nachgebildeten Simulation angewendet, validiert und diskutiert