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在最近的《航空学报》第3卷第3期中,江权伟等同志提出在没有轨道观测数据的情况下,仅凭借飞行器上过载和角速率测量数据,确定再入体空气动力系数的卡尔曼滤波方法。对此我提出不同看法与江权伟等同志共商榷。我认为:该文所建立的确定气动系数的数学模型是不可辨识的;在没有轨道观测数据,仅依靠过载和角速率测量数据的情况下,只能确定再入体气动力系数的比值,而不能准确地确定气动系数。 系统辨识理论告诉我们,对于一个系统辨识的数学模型,如果从参数空间至模型输入-输出空间的映象是一一对应的,这种模型就可辨识。如果对某系统辨识的数学模型,有多
In the latest issue of Journal of Aeronautics, Vol. 3, No. 3, Jiang et al. Proposed a Kalman filter method to determine the reentry aerodynamic coefficient based solely on the overloading and angular rate measurements of the aircraft in the absence of orbital observation data . In this regard, I put forward different views and Jiang Weili and other comrades to discuss. In my opinion, the mathematical model for determining the aerodynamic coefficient established in this paper is not discernable. In the absence of orbital observation data, only the ratio of the aerodynamic coefficients of reentry body can be determined only by relying on the data of overload and angular rate measurements Pneumatic coefficient can not be accurately determined. Systematic identification theory tells us that for a mathematical model of system identification, the model is recognizable if the mapping from the parameter space to the model input-output space is a one-to-one correspondence. If a mathematical model of system identification, how much