Comprehensive coverage of all aspects of space application oriented fault tolerance techniques • Experienced expert author working on fault tolerance for Chinese space program for almost three decades • Initiatively provides a systematic texts for the cutting-edge fault tolerance techniques in spacecraft control computer, with emphasis on practical engineering knowledge • Presents fundamental and advanced theories and technologies in a logical and easy-to-understand manner • Beneficial to readers inside and outside the area of space applications

Comprehensive coverage of all aspects of space application oriented fault tolerance techniques • Experienced expert author working on fault tolerance for Chinese space program for almost three decades • Initiatively provides a systematic texts for the cutting-edge fault tolerance techniques in spacecraft control computer, with emphasis on practical engineering knowledge • Presents fundamental and advanced theories and technologies in a logical and easy-to-understand manner • Beneficial to readers inside and outside the area of space applications

Fault-tolerant computers have been developed for applications that require a very high degree of hardware reliability, and it is frequently asked whether similar techniques can be brought to bear on software for critical applications, e.g., ascent guidance software on launch vehicles, launch-control software for ground computers, and control and command software. The principal techniques employed in hardware fault tolerance are seen to be applicable also through software fault tolerance: error detection, protective redundancy, and rollback provisions. Of course, they need to be implemented in a specific manner; particularly the redundancy must be provided by a different code than that used for the primary modules. The recovery block (proposed by Randell), with the addition of a watchdog timer, has been implemented in a number of skeleton routines and has been found quite suitable in connection with the established structure for spaceborne software. A reliability model is proposed that shows a very considerable reduction in failure probability even when the fault-tolerance provisions themselves are far from perfect. It is therefore believed that the time is quite ripe to undertake serious studies of fault-tolerant software for space applications. (Author).

Fault tolerance is explored for spacecraft computers employing Field-Programmable Gate Arrays (FPGAs). Techniques are investigated for tolerating Single Event Upsets (SEUs) caused by radiation in the space environment. A new architectural approach is proposed for achieving SEU tolerance that minimizes power and size overhead costs by reducing the precision with which error checking is done. This Reduced Precision Redundancy (RPR) approach is compared to the traditional Triple Modular Redundancy (TMR) method. A methodology is presented for quantifying the costs and benefits of various performance factors, and thereby determining optimal design solutions. This methodology considers reliability as a performance factor that can be traded-off against factors such as power, size and speed. An SEU simulation system is developed for studying the effect of SEUs on actual FPGA circuits. Live proton radiation testing and computer-controlled fault injection simulations demonstrate the effectiveness of RPR and TMR. Computer simulations of power usage demonstrate the savings achieved with RPR. RPR is as reliable as TMR while requiring 1/3 to 1/2 as much power. The effect of imprecise computations that may be produced by an RPR system is studied. An image processing application illustrates the type of problems for which RPR can be applied effect.

Software fault tolerance techniques involve error detection, exception handling, monitoring mechanisms, and error recovery. This issue of Trends in Software focuses on identification, formulation, application, and evaluation of current software fault tolerance techniques.

Look to this innovative resource for the most-comprehensive coverage of software fault tolerance techniques available in a single volume. It offers you a thorough understanding of the operation of critical software fault tolerance techniques and guides you through their design, operation and performance. You get an in-depth discussion on the advantages and disadvantages of specific techniques, so you can decide which ones are best suited for your work.