METHODOLOGY FOR QUORUM CONTROL OF THE REDUNDANT IRS SIGNALS IN THE MAIN MODE OF THE CIVIL AIRCRAFT CONTROL SYSTEM

Abstract

Modern civil aircraft control systems operate, as a rule, in two modes - main and standby. The main control mode provides full control functionality with appropriate limitation for the flight crew due to the presence of redundant signals from interacting systems (such as IRS, ADS etc.). The standby mode provides control of the main control surfaces, allowing to continued safe flight and landing, but loses most of the protective functions. The redundancy of signals from interacting systems and their monitoring makes it possible to avoid the loss of the main mode of the flight control system due to single failures. Monitoring of the signals of interacting three-channel systems is ensured mainly by voting quorum up to the second failure, which is not a practically improbable event in terms of CS-25. These methods include the method of calculating the average value and the method of calculating the median value of redundant signals. In this paper, we propose a technique for quoruming triple redundant systems that provides control up to the third failure. The technique consists in using a confidence parameter for each channel of the interacting system, depending directly on its previous values (ie, monitor by value history). The results show that the use of this methodology will reduce the probability of switching to a standby control mode by almost one order of magnitude (and becomes an almost improbable event), as well as improve economic performance by increasing the Minimum Equipment List.