Design And Implementation Of A Test System For Flight Control Unit

With the increasing development of aerospace technology,flight vehicle with more widely used in various fields.It involves a number of areas,such as military,meteorology,geology,carrying and the like.There are specific Sputnik launch vehicles,space exploration and so on.Currently,the cost of international spacecraft remains high.Flight accidents of aerial and space have still occurred.Event of an accident,the consequences could be disastrous.This will not only result in huge economic damage,serious environmental pollution and even casualties.Flight control unit is one of the core components in a flight vehicle.There are four main functions in the vehicle system.The functions are as follows:First,flight control unit receives signals output by sensitive devices for measuring,calculates by the program in real time and control execution units of vehicle to work coordinately.Second,according to flight displacement and velocity received,the engine and nozzle can be opened and closed by the flight control unit to ensure that the aircraft is flying at a predetermined orbit.Third,the flight control unit adjusts the posture to overcome external interference and maintain aircraft flying smoothly.Fourth,the flight status of the vehicle is monitored in real time through the detection of subtle signals.Fault information would be feedback timely.Due to the need of the flight mission,there are the characteristics of strong maneuverability,uncertain disturbance factor,complex fault and so on in the flight.It is essential to develop a comprehensive and efficient test system,which is able to carry out dynamic evaluation and test verification to the flight control unit.Improving the reliability of flight control unit and reducing flight risk level have important significance to advance the development of space technology.This article will set up an improved test system based on testing technology for flight control unit.The major contributions of the dissertation include:1.From the aspect of test coverage,there were researches on testing of the impedance domain,the time frequency domain,the power domain,the data domain and the real time domain.And seven kinds of testing methods were classified,namely,impedance test,unit test,signal test,correlation test,concurrent test,simulation test and diagnosis test;the testable features of flight control unit were extracted by using the method of Hardware Testability Stratified Analysis,and the classification was carried out according to the sevenkinds of testing methods;the failure modes of every layer were predicted.Four kinds of test techniques were studied,which are signal function class,signal performance class,real time simulation class and environment test class.2.According to functions and performances of the flight control unit,some standards of judgment were obtained by derating design.3.The overall scheme of the tested system was made.And the structural design,hardware design and solution for software test were completed also.4.The functions of the test system have been debugged and the stability and reliability of the test system have been verified by testing and experiments.Through the practical application,the improved design has a certain effect on improving the test coverage,improving the stability and anti-interference ability of the test system.