Patent ID: 7561944
Filing Date: 2009-07-14
Classification: B64C,G05D

Abstract:
1. A system comprising: a plurality of redundant pairs of computer systems; a plurality of actuators; and a plurality of line replaceable units with dual-dissimilar processing lanes, each of the plurality of line replaceable units being coupled to one of the plurality of actuators, each of the plurality of line replaceable units being configured to receive synchronous digital control data from each pair of computer systems of the plurality of redundant pairs of computer systems, wherein the plurality of redundant pairs of computer systems includes at least three redundant pairs of computer systems and wherein the plurality of line replaceable units includes three or more line replaceable units, wherein each line replaceable unit is configured to perform a validity check of each redundant pair of computer systems, wherein each line replaceable unit performs the validity check by determining if a freshness invalid signal and an error condition exists based on a corresponding digital control data and the freshness invalid signal, wherein each line replaceable unit determines if an error condition exists for each of the pairs of plurality of redundant pairs of computer systems by determining: if a difference between the digital control data of each computer system of a pair is greater than a threshold value, then a first constant value is added to an error value; if the difference between the digital control data from the computer systems of a pair of computer systems is less than the first threshold value, then a second constant value is subtracted from the error value; if the error value is greater than a second threshold value, then a line replaceable unit indicates that an error condition exists with respect to the pair of computer systems; and if the error value is at least equal to a third threshold value, then the line replaceable unit indicates that an error condition does not exist.