Automatic Integrated Evaluation For The Performance And Reliability Of Rudder System

Nowadays most modern civil aircrafts have made use of fly-by-wiretechnology, and their structures and functions are becoming more andmore complex and playing increasingly important role. Fly-by-wire controlsystem is one of the critical subsystems related to aircraft and flight safety,so its safety and reliability have become the primary design issues forflight control system that must be considered. For modern fly-by-wirecontrol system which is large and complex, traditional reliability analysismethods such as reliability block diagram (RBD) and fault tree (FT) arenot applicable.Therefore, this paper presents a method that integrates reliability andperformance evaluation into one framework, using probability measure toquantify the system reliability, so that reduces inconsistency between thesystem performance model and the reliability model. The main work is asfollows:(1) A new integrated method based on fault-tolerant system model andcomponent failure behavior model is presented, which uses Markov modelto carry on integrated analysis of reliability and performance of fault-tolerant system.(2) An automatic tool based on MATLAB/SIMULINK is developedto run the integrated evaluation of reliability and performance of fault-tolerant system. With this tool we can automatically evaluate the reliabilityand performances of systems defined by analyzers, and then weigh thepros and cons of different redundancy and fault tolerance strategies.(3) For fault-tolerant architectures of the posterior segment of rudder system, nominal behavior model of the system and fault behavior model ofits components are established, the reliability and performance of thesystem is analyzed and evaluated by simulation to identify the weak pointsin the system design; use STATEFLOW to implement several redundantand fault-tolerant solutions, and by simulation, pros and cons andeffectiveness of these several solutions are evaluated.