基于 Sobol 和 EFAST 法的枪弹转动角速度全局灵敏度仿真分析

For the needs of conducting exterior ballistic tests or studying flight dynamics, various devices for flight state measurement are often installed outside the bullets. Due to the interference of various random factors in the shooting and flight of bullets, the output of bullet borne measurement device is directly affected. In order to better design the experiment and process related data, this paper adopts the scheme of measuring the angular velocity of the bullet with the attitude measurement device. Using the five-degree-of-freedom rigid body trajectory equations, Sobol’s method based on Monte Carlo method for target practice and Extended Fourier amplitude sensitivity test method (EFAST) is used to analyze the influence of the output of attitude measurement on the sensitivity of initial velocity fluctuation, initial disturbance and other factors. The results of quantitative analysis show that: (1) The initial velocity and initial angle of attack have a great influence on the radial output of the attitude measurement device along the bullet body, and the initial velocity can significantly influence the axial output of the attitude measurement device; (2) Both Sobol’s method and the EFAST method can quantitatively analyze the contribution rate of parameters to output variables. However, EFAST is more robust and efficient.