The Design And Development Of Flutter Flight-Test Data Realtime Processing And Post-Processing Analyze System

In general terms, while in flutter phenomenon, aircraft will come into being airfoil or empennage fracture, even the whole aircraft disintegrate, which will lead to plane crash and man die。Flutter flight test is one of the most important part of aircraft structural dynamics test,it aims at verifying that in the giving designed limitation velocity flight envelope area, all configurations of the aircraft have no aeroelastic instability or pneumatic elastic instability。Through installing modal driver system on the test aircraft to incite various kinds flutter dangerous modal, the flutter flight test can experiment aircraft ‘s modal response characteristic,, it is the most dangerous risk subject, which need real –time monitoring in order to safeguard flying safety.The flutter parameters are quick-changing parameters。Comparing to other test subjects, flutter flight test has the characteristics of high risk and high sampling frequency, the parameters’ sampling frequency are larger than 512 points per second,normal monitoring system has low sampling frequency, which is unable to meet the demand of flutter flight test。Chinese Flight Test Establishment has no telemetry monitoring system in early stage of flutter flight test。From the ending of ninety decade to the beginning of this century, the flutter parameters utilize PCM telemetry data processing system gradually。In this stage,flight test engineers in monitoring hall can approximately find out the flight test through flutter parameters’ time-history curve, which is drew by bar-chart apparatus or notes apparatus,the exhaustive signal analysis should be waited until the flight terminate,the data processing program is:unload the data recorded by airborne->the first pretreatment( entire journey)->find out the time scale-> the second pretreatment(according to the time scale)->flutter signal analysis,the period of data processing is very long,generally speaking, one hour’s flight data can be acquired after the flight test has terminated 3 to 4 hours. In the process of monitoring, if the value of one parameter transfinite, monitoring software will be reminded by light ing the lamp or making a voice alarm. In the development of the whole system, database management subsystem and client monitoring software independently by the author.Aiming at the drawback existed in real-time monitoring system and post-processing analyze software, this paper developed a flutter signal real-time monitoring and analysis system on the basis of microcomputer network。The system can abstract all flutter parameters in high sampling rate, it can not only draw all flutter parameters’ time-history curve in bar-chart apparatus,but also can show them and other parameters on the computer screen, realize real-time monitoring; accomplish part of the parameters’ real-time fast Fourier transform, show frequency-domain mutative curve, realize risk subject cross-bound alarm; real-time save data according to the giving action slot, analyze flutter signal with real-time saving data after stimulate test or flight terminated. It bestially shortened the period of data processing, improved work efficiency。the data processing program is: the real-time saved data-> flutter signal analysis。This system has already invested to the flight test. After many model’s applications, it has made good progress.