Achieving fault tolerance in multichannel control systems

The authors present a review of three patented techniques for achieving a very high degree of fault tolerance in avionic multichannel control systems. The first technique involves the synchronization of the redundant channels using a fault tolerant hardware synchronizer. The symmetrization technique involves a unique architecture and algorithms for maintaining identical signals and configurations at the voting planes in the presence of transient, asymmetrical or Byzantine failures. Equalization is a systematic procedure for the chronological and hierarchical update of the appropriate historical databases of the channel(s) being restored, using the corresponding databases of the unaffected channels. Use of these proven techniques leads to a highly fault tolerant, reliable system in which all redundant channels operate identically, computing bit-for-bit identical outputs