时域极大似然法在某主控飞机等效横航向飞行品质辨识中的应用

Time-Domain Maximum Likelihood Method and its Application in the Identification of Aircraft Flying Quality Parameters

对某主动控制飞机横航向闭环飞行控制系统进行了数字仿真，为了模拟飞机在大气中的飞行，考虑了大气紊流的影响，然后利用时域极大似然法由仿真的飞行数据对该机横航向等效飞行品质进行辨识，结果是令人满意的。

It is more and more difTicult to evaluate flying qualitics of highly augmented aircraft. The generally employed method-Bode-Plot optimum matChing method-requires the determination of Bode-Plot, which is a high price to pay. In this paper, a method is proposed that bypasses Bode-Plot.The authors' method is called Time-Domain Maximum Likelihood method. Its merits are believed to be:(1) It allows direct use of aircraft flight test data, thus improving considerably computing efficiency and eliminating much abrasion of light control system unavoidable in ground test to determine Bode-Plot.(2) It uses time-domain signals and thus, different from Bode-Plot optimum matching method, its frequency is not limited to a narrow range and it docs not nced to select weight factors either.(3) Different from Bode-Plot optimum matChing method, it permits selecting initial values of parameters arbitrarily.Simulation study of a hi fighter equipped with digital flight control system indicates that the authors' method is promising. Finally, it is perhaps worthwhile to point out that the authors' method is applicable to other parameter identification problems.