Investigation On Methods Of Characteristic Parameters Identification Using Free-flight Range Data For Projectiles And Rockets

Free-flight range data of projectiles is necessary for the research of weapon and also plays an important role in the study of ballistics. Using the free-fight range data, various methods of aerodynamic parameters identification are analyzed and compared with each other. Therefore, a new kind of method for aerodynamic parameters identification is proposed in this dissertation.At present, Chapman-Kirk Method (OKM) and Maximum Likelihood Method (MLM) are both in popular for aerodynamic parameters identification. However, there are some problems, when using CKM, such as the fact that the value of objective function will probably increase after some certain iterative process, or the coefficient matrices of normal equation will probably become singular as the measurement is scarce or the estimating parameters are small, or it is extremely difficult to calculate the inverse matrix during the iterative process due to large dimensions. Aiming at all the problems concluded above, CKM is improved so as to meet the requirement of data processing for modern projectiles. The improved CKM is verified and compared with MLM by virtue of an example.At last, a new kind of method for aerodynamic parameters identification, based on the trend of aerodynamic parameters, is proposed and applied to a practical calculation example. The results indicate that this new method has generality, rapidity and accuracy for identification of aerodynamic parameters. Some conclusions above are useful for further research.