In this paper we show how the action semantics framework can be used to describe a particular implementation of fault-tolerant systems. We also de ne a notion of simulation which can be the basis for relating a fault-tolerant implementation to an abstract (non-faulty, and non-fault tolerant) speci cation. The aim of the paper is to illustrate that good software engineering techniques can be app...

More and more network-based services are considered essential by their operators: either because their unavailability might directly lead to economic losses, as with e-commerce applications or online auction services, for example, or because their well-functioning is crucial for the well-functioning of other services, which is, for example, the case for distributed file systems or coordination ...

One of the important features of digital instrumentation and control (I&C) systems is the faulttolerant technique. Fault-tolerance is the system’s capability to help the system perform correctly the specific required functions in spite of the presence of faults. In the fault tolerance evaluation, fault detection coverage is a crucial factor. The fault detection coverage is the ability to detect...

Fault-tolerant behavior is an important non-finctional requirement for systems that involve high criticality. We present a framework which allows the analysis of faulttolerant behavior to be undertaken. This framework is based on the notion of state machines and tolerance relations. Results concerning fault-tolerant behavior of finite-state machines are presented and an illustrative example is ...

In this paper, we deal with two important issues in relation to modular recon gurable manipulators, namely, the determination of the modular assembly con guration optimally suited to perform a speci c task and the synthesis of fault tolerant systems. We present a numerical approach yielding an assembly con guration that satis es four kinematic task requirements: reachability, joint limits, obst...

We investigate a novel adaptive fault-tolerant control method for time-varying failure in high-speed train computer systems and propose a fault model for such systems. First, the dynamics of high-speed train systems are analyzed and a multiple point-mass model is developed. When actuator outputs deviate from the expected value, a novel adaptive fault-tolerant control method based on Lyapunov st...

The paper deals with the problem of fault-tolerant embedded systems. To ensure the system’s fault tolerance, we use the multiple watchdog system that assigns a dedicated hardware watchdog timer to each of the concurrent processes. For sake of simplicity, effectiveness and adaptability, the watchdogs are implemented in the programmable hardware devices. This approach has several advantages and p...

In this paper, we present an approach to embed our formal Generic Fault Tolerant Software Architecture (GFTSA) model in the PVS theorem prover to achieve automatic verification support for reasoning about fault tolerant system properties. In order to make the verification process more efficient and systematic, we also propose a template approach for the auto-generation of specifications and pro...