In order to meet the requirements for future satellite applications, a brassboard of an extremely reliable fault-tolerant spaceborne computer (FTSC) has been developed by Raytheon Co., Sudbury, MA., under the sponsorship of the USAF/SAMSO. The requirements for the FTSC were high reliability, high speed, low power, high density and tolerance to space radiation environments. The reliability requi...

In earlier work we have introduced an efficient hardware fault-tolerant approach for reliable execution of tasks. The proposed approach called the Hardware Fault-Tolerant (HFT) approach. Also, we have introduced the concept of dynamic group maximum matching, which is used to group nodes of a graph into disjoint groups with different sizes dynamically. Furthermore, we have proposed the Dynamic G...

When a fault occurs in a system, the main problem to be addressed is to raise an alarm, ideally diagnose what fault has occurred, and then decide how to deal with it. The problem of detecting a fault, finding the source/location and then taking appropriate action is the basis of fault tolerant control. In this chapter, an introduction to fault tolerant control (FTC) and fault detection and isol...

We are considering a problem of faulttolerant wormhole unicast routing in computer networks, consisting of nodes (processor units), connected by bi-directional links. Each node can be viewed as the combination of a router and a processor with some RAM, bus and I/O circuitry. We concentrate on networks with arbitrary (irregular) topologies. The problem of routing in the presence of faults is div...

Task synchronization means that each redundant module has the same executing schedule in each task scheduling cycle of the operating system in the Triple Modular Redundancy (abbreviated TMR) fault-tolerant systems; it faces how to realize the coordination among the three modules. Therefore, it is necessary to investigate the task synchronization process of the TMR fault-tolerant system. In the ...

It has been usual to consider that the steps of program refinement start with a program specification and end with the production of the text of an executable program. But for fault-tolerance, the program must be capable of taking account of the failure modes of the particular architecture on which it is to be executed. In this thesis we shall develop a formal framework which shows how a progra...

The fault tolerant gait of legged robots in static walking is a gait which maintains its stability against a fault event preventing a leg from having the support state. In this paper, a fault tolerant quadruped gait is proposed for a hexapod traversing uneven terrain with forbidden regions, which do not offer viable footholds but can be stepped over. By comparing performance of straight-line mo...

There are no widely accepted design patterns for writing distributed, concurrent, fault-tolerant code. Each programmer develops her own techniques for writing this type of complex software. The use of a common pattern for fault-tolerant programming has the potential to produce correct code more quickly and increase shared understanding between developers. We describe rules, tasks, and pools, pa...

THE FAULT-TOLERANT QUANTUM COMPUTER I carried by a quantum system has notoriously weird properties. Physicists and engineers are now learning how to put that weirdness to work. Quantum computers, which manipulate quantum states rather than classical bits, may someday be able to perform tasks that would be inconceivable with conventional digital technology. (See the article by Charles H. Bennett...