Research On Testing Technology Of Terminal Ballistic Parameters Based On High-speed Camera

In order to test the combat performance of newly developed weapons,including obtaining weapon parameters,assessing weapons in service,and conducting projectile targeting tests in conventional live ammunition training and military exercises,to obtain parameters such as speed and angle at the moment when the projectile hits the target.These parameters are of great significance to the research on the guidance accuracy and damage effect evaluation of new weapons.Combined with the research status of this topic at home and abroad,and according to the requirements of the shooting range test task,this paper designs and builds the endpoint ballistic parameter test system.The system consists of four parts:synchronous control signal trigger module,remote wireless communication module,binocular camera convergence module,and end-point ballistic parameter test control system software.On the basis of the system platform,the following researches are carried out to obtain the target landing parameters.（1）In order to obtain the target parameters at the end of the ballistic end of the projectile,by studying the test mechanism of the ballistic parameters at the end point,including analyzing the transformation of four coordinate systems,pushing the three-dimensional coordinates of the projectile landing,and studying the analysis algorithm of the ballistic parameters at the end point,the projectile landing was obtained.expression.Design and build a test platform according to the requirements of the test system.（2）In order to improve the accuracy of the system testing target parameters,the camera parameter calibration method is studied.Analyze the conventional camera calibration method,study the sub-pixel corner coordinate extraction method,and detect the edge of the checkerboard based on the Hessian matrix method;analyze the camera calibration parameters,including the camera parameter matrix solution,camera lens distortion parameter correction,and the influence of distortion coefficient on the lens distortion model Analysis: Design related experiments using the degree of deviation between the measured coordinates of the feature points in the space and the real coordinates,and objectively evaluate the calibration error of the improved method.（3）In order to calculate the projectile landing parameters,the target extraction algorithm of the end-point ballistic image is studied.The projectile target contour extraction method is improved,and an improved five-frame difference method based on the image window area is proposed to effectively separate the projectile and the background from the target sequence image;the matching algorithm based on FLANN and KNN is carried out to realize the feature matching of the left and right camera images;To solve the void discontinuity in parallax,an improvement based on the region growing method is proposed to solve the parallax to make the parallax effect more dense.Through the obtained densification disparity map,combined with the camera calibration parameters and PCL software,the 3D point cloud data of the target landing is calculated,and then the projectile landing parameters are obtained.In this paper,the feasibility of the scheme is verified by simulation experiments by building an experimental platform of the test system.Use this system to measure the speed and angle of the bow and arrow when it hits the target,and compare it with the results of the canopy target speed measurement and manual angle measurement;by analyzing the results of three sets of test experiments,it can be seen that the maximum error of the system’s target speed measurement is 3.91%,and the average value is 1.56 %;the maximum measurement error of the horizontal target angle is 5.34%,and the average value is 2.25%;the maximum measurement error of the vertical target angle is 4.82%,and the average value is 2.36%.The experimental results show that the test system designed in this paper can meet the engineering requirements in terms of accuracy.