Tolerant Architectures

1993

An architecture based on controller redundancy for increased embedded real-time systems safety and availability is presented. The hot standby sparing technique, based on duplication with comparison is used; that means that two (COTS) controllers process the same input and the computed data is compared at the end of each cycle, as a mean to detect errors. When errors are detected, a diagnosis routine tries to identify the locality of the error. This may take some control cycles, which violates the real-time property of the controlled application. We argue that system real-time property should not be violated or, if so, the violation must not cause a crash of the controlled process. While the major part of the fault tolerance schemes concern about meeting deadlines, our scheme focuses on avoiding the process failure.

DEPEND 2011, The Fourth …, 2011

Abstract: This paper presents a method to make a dependable microcontroller-based system for detecting any violation from the program flow caused by transient faults. The method is based on a duplication and comparison technique and employs a “synchronous interrupt” ...

Proceedings of the seventh IEEE/ACM/IFIP international conference on Hardware/software codesign and system synthesis - CODES+ISSS '11, 2011

The paper presents an overview of a major research project on dependable embedded systems that has started in Fall 2010 and is running for a projected duration of six years. Aim is a 'dependability co-design' that spans various levels of abstraction in the design process of embedded systems starting from gate level through operating system, applications software to system architecture. In addition, we present a new classification on faults, errors, and failures.

A distributed fault tolerant system for real time process control based on an enhancement of the distributed recovery block is described. Coverage is provided for failures in hardware, system software, networks, and application software. Fault tolerance provisions are introduced at the system level and in application software using an architecture based on the distributed recovery block (DRB). This implementation allows use of standard off-the-shelf hardware and software components providing life cycle cost and extensibility benefits. Maintainability is enhanced through an automated restart capability and a logging function.

IEEE Transactions on Computers, 2000

This paper presents a fault-tolerant distributed system designed for real-time control applications (REBUS), which is one of the research basis of the industrial real-time system MODUMAT 800. It is made up of functional units, i.e., programmable multiloop regulators and operator displays, linked together by a communication structure. The communication hardware consists of a set of serial bus interface boards, one per functional unit, loosely coupled together by a double serial bus and linked to their functional units by a private parallel bus.

2014

Fault-tolerance technique enables a system or application to continue working even if some fault /error occurs in a system. Therefore, it is vital to choose appropriate fault tolerant technique best suited to our application. In case of real-time embedded systems in a space project, the importance of such techniques becomes more critical. In space applications, there is minor or no possibility of maintenance and faults occurrence may lead to serious consequences in terms of partial or complete mission failure. This paper describes the comparison of various fault tolerant techniques for space applications. This also suggests the suitability of these techniques in particular scenario. The study of fault tolerance techniques relevant to real-time embedded systems and on-board space applications (satellites) is given due importance. This study will not only summarize fault tolerant techniques but also describe their strengths. The paper describes the future trends of faults-tolerance t...

Proceedings 8th Euromicro Workshop on Parallel and Distributed Processing, 1999

Available solutions for fault tolerance in embedded automation are often based on strong customisation, have hnpacts on the whole life-cycle, and require highly specialised design teams, thus making dependable embedded svstenis costly and difficult to develop and maintain . The TIRf4u1r project develops a fraineivork which provides fault tolerance capabilities to automation svstenis, with the goal ofa/lowing portable, reusable and cost-effective sobuions . Application developers are allowed to select, configure and integrate in their own environment a variety of software-based functionsfor error detection, confinement and recovers provided by theframework. Market investigations with users and producers of automation systems have recognised the benefits offered by dependable systems, not only in the classical area of safetycritical tasks, but also in mission-critical ones, clue to the high economic impact of failures . Moreover, dependable ESPRIT Project 28620 TIRAN -'Tailorable fault tolerance frameworks for embedded applications" .

Critical real-time embedded systems need to make use of fault tolerance techniques to cope with operation time errors, either in hardware or software. Fault tolerance is usually applied by means of redundancy and diversity. Redundant hardware implies the establishment of a distributed system executing a set of fault tolerance strategies by software, and may also employ some form of diversity, by using different variants or versions for the same processing. This work proposes and evaluates a fault tolerance framework for supporting the development of dependable applications. This framework is build upon basic operating system services and middleware communications and brings flexible and transparent support for application threads. A case study involving radar filtering is described and the framework advantages and drawbacks are discussed.

2013

To my honest and diligent wife, Wang Fangyu To my lovely daughter, Xia Jingshu YX Contents Preface xv Acknowledgments xvii 1 Introduction 1.1 Overview 1.2 Basic Concepts of Faults 1.3 Classification of Fault Detection Methods 1.3.1 Hardware redundancy based fault detection 1.3.2 Plausibility test 1.3.3 Signal-based fault diagnosis 1.3.4 Model-based fault detection 1.4 Types of Fault-Tolerant Control System 1.5 Objectives and Structure of AFTCS 1.6 Classification of Reconfigurable Control Methods 1.6.1 Classification based on control algorithms 1.6.2 Classification based on field of application 1.7 Outline of the Book 1.7.1 Methodology 1.

Proceedings 6th IEEE International On-Line Testing Workshop (Cat. No.PR00646), 2000

Engineering and Applied Science Research, 2016

This paper proposes a design of fault-tolerance technology, combined with a Real-Time Operation System (RTOS), applied to a multi-microcontroller system. The aim of this work is to demonstrate the above issue via an embedded system with a “fault-tolerance” on a FreeRTOS kernel and driven by a multi-microcontroller system. A simple protocol that used to communicate between microcontrollers is USART with the feature of a high-speed baud rate at 10.5 Mbit/s. Sift-out modular redundancy, one of hybrid redundancy techniques in fault-tolerance algorithm has applied in this work. The experiments covered two types of faults; Slave Fault and Master Fault. The results showed that faults occurred in the proposed multi-microcontroller system can be detected and recovered in order to finish the whole assigned process.

[1989] Proceedings. Real-Time Systems Symposium, 1989

A new fault tolerant architecture that provides tolerance to a broad scope of hardware, software, and communications faults is being developed. This architecture relies on widely commercially available operating systems, local area networks, and software standards. Thus, development time is significantly shortened, and modularity allows for continuous and inexpensive system enhancement throughout the expected 20-year life. The fault containment and parallel processing capabilities of computers network are being exploited to provide a high performance, high availability network capable of tolerating a broad scope of hardware, software, and operating system faults. The system can tolerate all but one known (and avoidable) single fault, two known and avoidable dual faults, and will detect all higher order fault sequences and provide diagnostics to allow for rapid manual recovery.

2006

Abstract Fault tolerance is an important aspect in real-time computing. In real-time systems, tasks could be faulty due to various causes. Faulty tasks may compromise the safety and performance of the whole system and even cause disastrous consequences. In this paper, we study the possibilities of applying feedback control of software execution to real-time systems for fault tolerance purposes. A new fault tolerance architecture called ORTGA (On-demand Real-Time GuArd) is proposed.

International Journal of …, 2011

Software has rapidly become an important and indispensable element in many aspects of our daily lives. If such element is not running as on our need, we have to go through the problems about it. In initially, the paper focus on the different types of faults, their impact and fault classification. Faults are subdivided into different activities such as fault prediction, fault detection, fault prevention, fault correction etc. Here we study the faults in context boiler system. The concern thing is Faults classification as external, location, duration, and effect, permanent, temporary and may more. Any fault arise within system can be avoid, prevent or removed. Then we propose the different fault tolerance techniques to deal with different faults.