Research Of Aerodynamic Parameter Identification For Rocket

This paper mainly research on aerodynamic parameter identification technology, the mainpurpose of research is to extract some important aerodynamic parameters from the rockettrajectory data through the range measurement. Aerodynamic parameter plays a veryimportant role in the calculation and control of trajectory. But these parameters cannot bedirectly obtained by measuring, even though the parameters are obtained by using theoreticalanalysis and wind tunnel testing, the error is so large that can not meet the requirement. It is afeasible method that Aerodynamic parameters are extracted from the measured data withthe parameter identification method, it’s accuracy can meet the needs of the users.This paper analyzes the commonly used three methods of parameter identification, andputs forward a parameter identification method with comparing their advantages anddisadvantages, this method is proposed based on the principle of least squares. The Isightsoftware has more than ten kinds of optimization methods, the comprehensive algorithmlibrary is helpful for reducing the difficulty of the work and improving the accuracy of theidentification results.This paper analyzes the force and motion law of typical rocket, then establishes theballistic equation with four degree of freedom of the rocket; the idea of parameteridentification method based on Isight is proposed, then we establish a parameter identificationmodel, including selecting the design variables, establishing the objective function andselecting the optimization algorithm, etc. This paper mainly uses the LSGRG algorithm,Hooke-Jeeves algorithm and the combinatorial optimization strategy that based onMulti-Island genetic algorithm,etc; With the sample data of known true value, taking asimulation calculation and carrying on the thorough determination for sample data, alsoproving the correctness and feasibility of the method; Finally, identifying the rangemeasurement data of a typical rocket projectile by using combinatorial optimization strategy,and the results show that the method is feasible in practical engineering application, and theprecision is high. The method proposed in this paper has good portability, high flexibility and generality，and provides a new idea for aerodynamic parameter identification.