| Both the impacting coordinates and the velocity of the flying projectile are the key parameters to measure the weapons danmage performance,and they are the essential parameters measured in the process of the range tests, and are the supporting and critical data for the engineering designmdesign finalization,acceptance and fault diagnosis of the higlh-tech weapons systems. The light-screen array neasurement method has the advantages of new principle, high sensitivity, high accuracy and low cost, etc. It has been widely applied in the field of the external ballistic measurement. Aiming at the technical problems that the light-screen array model only can be used to the uniform speed and straight line trajectory, and can't measure flight parameters of the projectile with the variable velocity curvilinear trajectory,it is important to research the measurement method of projectile flight parameter with variable velocity curvilinear trajectory, and it has great scientific significance and wide application value.This thesis mainly introduces the five contents as following:1. The six light-screen array model to measure flight parameters of the projectile with uniform speed and straight line trajectory has been built up. Based on the operating principle of light-screen sensor, the general formula of spcace plane equation is used to describe spatial position of light-screen, and to set up the topological structure matrix of the litght-screen array in this thesis. A linear motion equation is established depending on the time sequence of the projectile with the uniform-linear motion, combine the equations matrix of the light-screen array, the projectile impacting coordinates and the velocity vector can be worked out. In terms of the relative spatial position of multi-light-screens, the basic formation and evolution of formation for light-screen array are presented in this thesis.2. The method of six light-screen array on measuring flight parameters of the projectile with variable velocity curvilinear path has been put forward. The actual ballistic trajectory is variable velocity curvilinear one due to the serious impact from the gravity and air resistance to the projectiles in the terminal ballistic range, so a new formula for calculating the flight parameters of the projectile is proposed. With regard to the spectial test projectile, a corresponding parallel light screen is added on the six light-screen array with the method of attenuation for the two-point velocity to measure the air drag acceleration and then modify the projectile motion curve equation. In the overall consideration of the influence factors on measurement model, the error analysis on the measuring formula is made by means of the matrix derivative.3. A method for calculating the characteristic moment of the projectile passing through the inclined trapezoid is presented. Regarding to the trapezoidal distribution of actual thickness of lens-light-screen and the output signal differences at the moment of projectile passing through the light-screen with different angles, a mid-screen trigger algorithm is proposed and studied.The mid-screen trigger signal amplitude ratio is calculated based on the thickness of light-screen spatial angle, the screen angle of inclination and the projectile flight vector. The moment of projectile tail arriving at the mid-light-screen is calculated accurately by iterative algorithm, together with measuring formula on light-screen array. The effectiveness of algorithm is verified by one-dimensional horizontal convolution simulation calculation between the projectile image and trapezoidal screen image.4. Referring to the key technology in the process of the light-screen array engineering realization, both the single-len light-screen and the single-len three light-screen models have been compared and analyzed, the application ranges of each model are studied and the optimal angles among light screens ?1,?2?[35°,50°],??[60°,75°] are calculated by simulation. In consideration of the engineering realization of the indoor light-screen array, the N type arc-shaped linear array light source is designed to study the sensitivity distribution of different sensor position. Combined with the new measuring model proposed in the thesis the light-screen is verified by measuring the projectile impacting coordinates of rifle and the operating distance of proximity fuse.5. Based on the subdivide light-screen array, the method of measuring the projectile's flight parameters of the multi-projectiles, which are hitting the light-screen at the same time is proposed. Making some small-size light-screens in the same plane forms the double V type six light-screen array. The light-screen detecting area is subdivided according to the array gun-barrel spatial layout. Based on the principle of equal time of the projectile passing through symmetrical light-screensand the different times of projectiles that are in different positions going through the inclined light screens, the time sequencesof projectilesare identified and sequenced to determine the combination of time sequence of each projectile passing through the light screen array, so that the flight parameters of transient multi-projectiles are measured accurately in combination of measuring formula for light-screen array.The flight parametersof the projectilewith variable velocity curvilinear trajectory are studied further by theoretical analysis combined with tests in this thesis, and the innovative research achievements are that: the presentation of general screen array measurement model and the essential condition of light-screen array measurability, the derivation of the mathematical expressions with unique solution of the projectile flight parameters and revelation of the establishment rules of light-screen array. And then the measuring formula of the flying projectile with variable velocity curvilinear trajectory is derived to accuratelymeasure the flight parameters in great intercept ballistic section. The algorithmon the light-screen time sequence of the projectile slantly passing through trapezoidal screen is proposed, which are free of disturbance of signal processing circuit gain, intersection angle and inclination of the light-screen and the differentpositions of projectile passing through the light-screen. It has the high consistency, so that the measurement precision of the system is improved. The model and the algorithm of the light-screen array are verified by the tests of real fire, compared withthe uniform speed straight measurement model, themeasurement precision of impacting coordinatesis optimized by 3 mm at least, and it can measure the flight parameters of the projectilewith variable velocity curvilinear trajectory. The flight parameters measurement method of multi-projectiles impacting the light-screen simultaneously is put forward based on the subdivide light-screen array model, which provides a new way for accurately measuring the flight parameters ofmulti-objectives.The research result can be popularizedto the variable velocity curvilinear trajectory and multi-objectives measurement, whichprovidesthe reliable technology support for the projectile flight parameters in the terminal ballistic trajectory of the high-tech weapons. |
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