Then a low pass filter is designed to filter high - frequency noise in data . and smooth data again by means of central interpolation algorithm ; helicopter model with multi input single output are identified respectively in ls method and ml method ( 2 )剔除并補正了飛行實驗數(shù)據(jù)中的野值;設(shè)計了一個低通濾波器來濾除數(shù)據(jù)中的高頻噪聲;用中心插值算法對數(shù)據(jù)二次平滑。