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This paper presents a novel communication architecture denoted as time-triggered (TT) Ethernet that integrates real-time and non-real-time traffic into a single communication architecture. TT Ethernet supports applications of different levels of criticality, from simple data acquisition systems, to multimedia systems up to the most demanding fault-tolerant real-time control systems. The event triggered traffic in TT Ethernet is handled in conformance with the existing Ethernet standards of the IEEE. The architecture deploys a TT Ethernet switch, which distinguishes between event-triggered (ET) and time-triggered (TT) Ethernet traffic. Time-triggered traffic is transmitted with a predictable transmission delay, whereas event-triggered traffic is transmitted on a best-effort basis. The paper elaborates on the usage of TT Ethernet for in-vehicle communication in order to integrate different in-vehicle communication subsystems into a single communication architecture.

The Time-Triggered Architecture (TTA) is a distributed architecture for high-dependability real-time systems such as break-by-wire or steer-by-wire systems. This paper is devoted to the fault-tolerance and fault-handling capabilities of the TTA. We will present the architectural and algorithmic features of the time-triggered communication protocol TTP/C that allow isolation of arbitrary failures of a node-computer in the distributed system. Having node failures isolated, the introduction of redundant nodes accompanied by voting services located in a generic fault-tolerance layer makes the architecture tolerant to Byzantine failures of node-computers. We will also present the mechanisms that detect multiple failure scenarios at the communication system level and provide means for rapid handling of and deterministic recovery from such situations.

In the new century the automotive industry is transforming itself from an entirely mechanical industry to an industry that is driven by electronics and services. The companies who will be most successful are those who are able to control, drive and renew the architectural concepts enabling the introduction of state-of-the-art information technology to the car and its supporting infrastructure. This paper will first define the term architecture and will elaborate about the increasing relevance of architectural thinking in the automotive domain. Architectural leadership will be defined to mean control (proprietary ownership of components and/or interfaces), creation of a de-facto or legal standard as well as renewal (creation of new products and markets utilizing new linkages of existing architectures). In the second part examples of successful and less successful approaches for establishing architectural leadership in the automotive industry are discussed.

The next generation of automotive control systems will consist of a set of networked electronic control units (ECUs) that operate in tight coordination to achieve the desired optimal control of the vehicle. The design of these systems must be guided by a composable system architecture that supports the constructive integration of the independently developed components. This paper discusses the four principles of composable architectures and shows how the interoperability of the ECUs is achieved in the time–triggered architecture.

The SAE has classified automotive electronics into two major categories, body electronics and system electronics. The latter (SAE class C) comprises safety critical functions that are of vital importance for the movement of the vehicle. This paper presents a prototype implementation of TTP, a time-triggered communication system developed for this type of applications. The main purpose of the prototype is to provide a means for verifying the concepts of TTP. The paper focuses on a description of the hardware developed for the communication system as well as the protocol software. The TTP controller hardware is a custom made industry pack module which allows the use of TTP in conjunction with a wide variety of existing motherboards and host environments. The protocol software consists of a TTP/C protocol state machine and auxiliary modules to access the various hardware units.

The provision of a system-wide global time base with good precision and accuracy is a fundamental prerequisite for the design of a time-triggered automotive real-time control system. In this paper we investigate the issues of clock synchronization in such a system. Our synchronization scheme allows every node to have a different oscillator. Based on typical parameters we derive the achievable precision and accuracy, which is in the microsecond range. The description of a prototype implementation shows the applicability of our approach.

A time-triggered communication protocol that derives its control information (e.g., when to send a message) from the progression of time offers unique features that meet the stringent demands of automotive class C control applications. The interface to a dedicated network controller executing such a protocol can be viewed as a system wide interface and is thus a perfect starting point for the system's decomposition into autonomous, non-interfering subsystems. This paper presents such a network controller interface that allows applications to transparently access the services of the underlying communication protocol. The interface is designed as a data-sharing interface, i.e., the flow of control information across the interface is restricted to the necessary minimum. With this, the chance of control error propagation is reduced considerably. The interface acts as a temporal firewall facilitating independent subsystem development and validation.