METHOD AND APPARATUS FOR IMPLEMENTING A DATABUS VOTER TO SELECT THE COMMAND SIGNALS FROM ONE OF SEVERAL REDUNDANT ASYNCHRONOUS DIGITAL PROCESSING UNITS

摘要

Asynchronous, triple redundant primary flight computers (PFC's) (12, 14, 16) produce output command signals carried over data buses (18) to control redundant actuators (32, 34, 36) in an aircraft flight control system. To prevent the transmission of a fault and a force fight among the redundant actuators, which drive a common aircraft control surface (50), a databus voter (52, 54, 56) associated with each PFC receives all PFC commands and, in accordance with a selection algorithm, outputs a voted one of the PFC command signals. A databus voter monitor (144), associated with each databus voter, deactivates its associated databus voter if it detects a voted command signal which is inconsistent with the selection algorithm.