撞击角度和速度已知条件下的球形弹丸飞行弹道轨迹算法  

Algorithm on Trajectory of Spherical Projectile with Known Impacting Angle and Velocity

作　　者：董必强 何维予[2] 刘光宙[1] 房诚[1] 张进忠[1] DONG Biqiang;HE Weiyu;LIU Guangzhou;FANG Cheng;ZHANG Jinzhong(Evidential Material Identifi cation Offi ce,Gulou Branch of Nanjing Public Security Bureau,Nanjing 210036,China;High School Affi liated to Nanjing Normal University,Nanjing 210000,China)

机构地区：[1]南京市公安局鼓楼分局物证鉴定室,南京210036 [2]南京师范大学附属中学,南京210000

出　　处：《刑事技术》2021年第1期46-51,共6页Forensic Science and Technology

基　　金：痕迹科学与技术公安部重点实验室开放课题(2019FMKFKT03)。

摘　　要：针对刑侦工作中弹打玻璃类案件的侦破难点,研究一种用于计算球形弹丸抛射击打玻璃案件中弹丸飞行轨迹的算法。本文以弹丸撞击角度和撞击速度为基础参数,在阐明前置基础数据的前提下,将弹打玻璃类案件中的玻璃窗分为垂直于地面及倾斜于地面两类,采用三角函数计算和参数替换的方法,通过对弹丸撞击瞬间的弹道参数设定、弹孔图像在玻璃平面内的二维图像参数设定、相关角度的描述、计算抛物线轨迹与弹道轨迹朝向等一系列步骤,最终,研究出上述两类玻璃窗的弹道轨迹计算方法。研究表明,弹丸弹道飞行轨迹算法可以还原弹丸飞行的轨迹抛物线,作为现场弹道轨迹重建系统的核心算法使用,为开发弹打玻璃类案件的现场弹道轨迹重建系统提供了关键技术。From time to time,such cases occur of building(usually window)glass having been broken with projectiles(bullet/pill/slug/pellet),leaving some diffi cult for investigators to solve.For these cases,the projectiles and their trajectories are the key clue and evidence.Therefore,this paper tries to design an algorithm to compute the ballistic trajectory of the projectile hitting towards the glass.This exploration takes the projectile’s impacting angle and velocity as basic parameters.The targeting windowpane is set under two conditions:vertical and/or tilting to the ground.Trigonometric function numeration and parameter substitution are used into calculation.Through the presetting or reverse extrapolation of several jointing parameters/factors(i.e.,the ballistic parameters just at the impacting moment,the two-dimensional image parameter of bullet hole on the glass surface,the relevant angles,the parabolic track,the direction of ballistic trajectory),the ballistic trajectories are finally established about the projectile hitting glass under the two conditions.With simulation,such an algorithm of ballistic trajectory can reappear the parabolic trajectories of small spherical objects.This computation algorithm could play its role into investigating the cases with the pertinent trajectory to simulate the projectile hitting building glass.

关 键 词：痕迹学 弹丸撞击 弹道轨迹 三角函数 

分 类 号：DF794.1[政治法律—诉讼法学]