Modeling and verifying the FlexRay physical layer protocol with reachability checking of timed automata

In this thesis, I report on the verification of the resilience of the FlexRay automotive bus protocol's physical layer protocol against glitches during message transmission and drifting clocks. This entailed modeling a significant part of this industrially used communictation protocol and the underlying hardware as well as the possible error scenarios in fine detail. Verifying such a complex model with model-checking led me to the development of data-structures and algorithms able to handle the associated complexity using only reasonable resources. This thesis presents such data-structures and algorithms for reachability checking of timed automata. It also present modeling principles enabling the construction of timed automata models that can be efficiently checked, as well as the models arrived at. Finally, it reports on the verified resilience of FlexRay's physical layer protocol against specific patterns of glitches under varying assumptions about the underlying hardware, like clock drift.In dieser Dissertation berichte ich über den Nachweis der Resilienz des Bitübertragungsprotokolls für die physikalische Schicht des FlexRay-Fahrzeugbusprotokolls gegenüber Übertragungsfehlern und Uhrenverschiebung. Dafür wurde es notwendig, einen signifikanten Teil dieses industriell genutzten Kommunikationsprotokolls mit seiner Hardwareumgebung und die möglichen Fehlerszenarien detailliert zu modellieren. Ein so komplexes Modell mittels Modellprüfung zu überprüfen führte mich zur Entwicklung von Datenstrukturen und Algorithmen, die die damit verbundene Komplexität mit vernünftigen Ressourcenanforderungen bewältigen können. Diese Dissertation stellt solche Datenstrukturen und Algorithmen zur Erreichbarkeitsprüfung gezeiteter Automaten vor. Sie stellt auch Modellierungsprinzipien vor, die es ermöglichen, Modelle in Form gezeiteter Automaten zu konstruieren, die effizient überprüft werden können, sowie die erstellten Modelle. Schließlich berichtet sie über die überprüfte Resilienz des FlexRay-Bitübertragungsprotokolls gegenüber spezifischen Übertragungsfehlermustern unter verschiedenen Annahmen über die Hardwareumgebung, wie etwa die Uhrenverschiebung.DFG: SFB/TRR 14 "AVACS - Automatische Verifikation und Analyse komplexer Systeme

An object-based codesign methodology.

The research into Codesign of Hardware and Software stems from the development of embedded systems, on which various systems restrictions are imposed. Typical restrictions can be the overall time (latency) to complete an assigned function and the space/power limits within the system. Although software can be used to undertake most tasks in an embedded system, ASIC (Application Specific Integrated Circuits) hardware components sometimes have to be recruited to meet the system constraints. Designing the restricted embedded system with both software and hardware components in it involves the analysis of not only individual hardware/software components but also their mutual influences. Using co-design principles, the approach is to consider both hardware and software from a coherent viewpoint.This thesis presents the results from our research project in the area of Codesign of Hardware and Software. In this project, we investigated previously published codesign approaches and their methodological supports. The investigation has identified shortcomings and problems with the existing codesign methodologies. A new object-based codesign approach (Co-PARSE) is thus developed in this project, which is supported by successive phases, guidelines, and techniques. This methodology offers a coherent design framework for real-time embedded systems and incorporates the criteria of system performance and hardware cost. Tools have been developed to facilitate the use of the methodology. Within the methodology, a high-level system modeling and specification approach has been developed and formalised in the Co-BSL (Codesign Behavior Specification Language). The means of transforming Co-BSL specifications to C and VHDL implementations is defined, and a library of VHDL components provided. The thesis documents the partitioning approach taken within the methodology and proposes a new multi-layered bus architecture as a basis for more flexible and efficient implementations. A means of simulating the performance characteristics of this architecture under different configurations is provided, and examples of simulation results are presented. A new embedded system (the Radio Data Computing System) is designed and simulated in the Co-PARSE methodology and simulation results analysed. The thesis concludes with an evaluation of the work carried out in the project and proposals for extending the results obtained in future research.The major contributions reported in this thesis can be summarised as follows. First, the unified system specification means has been designed, which is embodied in the Co-BSL. It captures overall dynamic aspects and performance constraints in the system under development. This high-level specification language is independent of implementation and does not bias the designer towards the use of hardware or software components at this early stage. Second, within Co-PARSE, the target architecture of the system under development has been exploited to improve the system performance and at the same time to reduce hardware cost. This novel concept has been realised by the introduction of an asynchronous bus protocol and the multi-layer bus communication structure. Third, in order to evaluate the strength and practicability of the Co-PARSE methodology, an extensive case study has been carried out. The new RDC (Radio Dada Computing) System has been designed in the proposed codesign approach. Codesign phases are subsequently applied and the guidelines and tools that are specially developed in support of the methodology are fully utilized

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project. ACT/Control/Guidance System study, volume 1

The active control technology (ACT) control/guidance system task of the integrated application of active controls (IAAC) technology project within the NASA energy efficient transport program was documented. The air traffic environment of navigation and air traffic control systems and procedures were extrapolated. An approach to listing flight functions which will be performed by systems and crew of an ACT configured airplane of the 1990s, and a determination of function criticalities to safety of flight, are the basis of candidate integrated ACT/Control/Guidance System architecture. The system mechanizes five active control functions: pitch augmented stability, angle of attack limiting, lateral/directional augmented stability, gust load alleviation, and maneuver load control. The scope and requirements of a program for simulating the integrated ACT avionics and flight deck system, with pilot in the loop, are defined, system and crew interface elements are simulated, and mechanization is recommended. Relationships between system design and crew roles and procedures are evaluated

Machine-Assisted Parameter Synthesis of the Biphase Mark Protocol Using Event Order Abstraction

We present machine-assisted timing-parameter synthesis of the biphase mark protocol (BMP) [1] using event order abstraction (EOA)[2]. By using EOA, we separate the task of synthesizing parameter constraints that guarantee key safety properties of BMP into two parts: 1. Safety property verification of the protocol by a conventional untimed model-checker under the condition that “bad” event orders do not occur; and 2. Derivation of timing parameter constraints that are sufficient to exclude bad event orders in the protocol, using our tool METE-ORS. Though the user has to provide information about bad event orders, the rest of the synthesis process is automated. With the case study presented in this paper, we provide the community with two new pieces of information about BMP. First, the synthesis process using EOA produces, as a by-product, a list of all “bad scenarios ” of BMP that would happen when parameters are tuned incorrectly. Second, the METEORS tool provides information about which parameter constraint in the finally derived conjunction of constraints is actually sufficient to exclude each of these bad scenarios

Laboratory directed research and development. FY 1995 progress report

This document presents an overview of Laboratory Directed Research and Development Programs at Los Alamos. The nine technical disciplines in which research is described include materials, engineering and base technologies, plasma, fluids, and particle beams, chemistry, mathematics and computational science, atmic and molecular physics, geoscience, space science, and astrophysics, nuclear and particle physics, and biosciences. Brief descriptions are provided in the above programs

NASA Tech Briefs, March 1995

This issue contains articles with a special focus on Computer-Aided design and engineering amd a research report on the Ames Research Center. Other subjects in this issue are: Electronic Components and Circuits, Electronic Systems, Physical Sciences, Materials, Computer Programs, Mechanics, Machinery, Manufacturing/Fabrication, Mathematics and Information Sciences and Life Science

Battery Systems and Energy Storage beyond 2020

Currently, the transition from using the combustion engine to electrified vehicles is a matter of time and drives the demand for compact, high-energy-density rechargeable lithium ion batteries as well as for large stationary batteries to buffer solar and wind energy. The future challenges, e.g., the decarbonization of the CO2-intensive transportation sector, will push the need for such batteries even more. The cost of lithium ion batteries has become competitive in the last few years, and lithium ion batteries are expected to dominate the battery market in the next decade. However, despite remarkable progress, there is still a strong need for improvements in the performance of lithium ion batteries. Further improvements are not only expected in the field of electrochemistry but can also be readily achieved by improved manufacturing methods, diagnostic algorithms, lifetime prediction methods, the implementation of artificial intelligence, and digital twins. Therefore, this Special Issue addresses the progress in battery and energy storage development by covering areas that have been less focused on, such as digitalization, advanced cell production, modeling, and prediction aspects in concordance with progress in new materials and pack design solutions