This study investigates and quantifies some possible sources affecting the position of impact points of small caliber spin-stabilized projectiles (such as 12.7 mm bullets). A comparative experiment utilizing the control variable method was designed to figure out the influence of tiny eccentric centroids on the projectiles. The study critically analyzes data obtained from characteristic parameter measurements and precision trials. It also combines Sobol’s algorithm with an artificial intelligence algorithm—Adaptive Neuro-Fuzzy Inference Systems (ANFIS) – in order to conduct global sensitivity analysis and determine which parameters were most influential. The results indicate that the impact points of projectiles with an entry angle of 0° deflected to the left to that of projectiles with an entry angle of 90°. The difference of the mean coordinates of impact points was about 12.61 cm at a target range of 200 m. Variance analysis indicated that the entry angle – i.e. the initial position of mass eccentricity – had a notable influence. After global sensitivity analysis, the significance of the effect of mass eccentricity was confirmed again and the most influential factors were determined to be the axial moment and transverse moment of inertia ($I\text{zz}$ $Iyy$), the mass of a projectile ($m$), the distance between nose and center of mass along the symmetry axis for a projectile ($L_{\mathrm{m}}$), and the eccentric distance of the centroid ($L_{\mathrm{r}}$). The results imply that the control scheme by means of modifying mass center (moving mass or mass eccentricity) is promising for designing small-caliber spin-stabilized projectiles.

本研究调查并量化了影响小口径自旋稳定弹丸（如12.7毫米子弹）撞击点位置的一些可能来源。设计了一个使用控制变量方法的比较实验，以找出微小的偏心质心对弹丸的影响。该研究严格分析了从特征参数测量和精密试验获得的数据。它还将Sobol的算法与人工智能算法-自适应神经模糊推理系统（ANFIS）相结合，以便进行全局敏感性分析并确定最有影响力的参数。结果表明，入射角为0°的弹丸的冲击点向左偏转为入射角为90°的弹丸。在200 m的目标范围内，冲击点的平均坐标差约为12.61 cm。方差分析表明，入射角（即质量偏心率的初始位置）具有显着影响。经过整体灵敏度分析后，再次确认了质量偏心影响的重要性，并且确定了影响最大的因素是轴向惯性矩和横向惯性矩（$\mathrm{一世}\text{Z Z}$ $\mathrm{一世}ÿÿ$），射弹的质量（$米$），鼻子和质心沿弹丸的对称轴的距离（${\mathrm{大号}}_{\mathrm{米}}$），以及质心的偏心距（${\mathrm{大号}}_{\mathrm{[R}}$）。结果表明，通过修改质心（运动质量或质量偏心率）的控制方案有望用于设计小口径自旋稳定弹丸。