Research On Multi-Parameter Measurement Technique Of Fragment Based On Intermittent Laser High Speed Photography

Fragment testing is an important means to evaluate the damage ability of flight fragments and obtain the dynamic parameters of fragments.In the aspect of weapon application,fragmentation is an important part of the damage target of weapon equipment.The parameters of fragmentation speed,quantity and flight Angle are important indicators to evaluate the damage ability of weapon equipment.In aerospace applications,the speed,size,shape characteristics and contact attitude of space fragments can provide effective data support for the safety protection design of aircraft.Among many fragment testing methods,image testing method has become an efficient testing method in fragment multi-parameter testing because of its intuitive results and many available parameters.However,due to the transient characteristics of fragment and the resulting parasitic effects,higher requirements are put forward for fragment image testing.Therefore,the multi-parameter image measurement technology of flying fragments is studied in this paper.Firstly,this paper summarizes the existing fragment testing technologies at home and abroad,and based on the shortcomings of fragment image testing,a fragment multi-parameter testing method is proposed,which aims to obtain multiple high-resolution fragment instant images.The working principle of fragment multi-parameter testing is described and the fragment multi-parameter testing framework is built.The modular analysis method is adopted to divide the overall testing technology into five modules,and each module is analyzed and studied.The research content includes the discussion of working principle,the analysis of working content,the comparative selection of working mode and the deduction of working parameter formula.Secondly,the lighting source technology of fragment multi-parameter testing system is studied.Based on the module analysis of photographic lighting source,the theory of intermittent multi-pulse laser source suitable for fragment multi-parameter testing is proposed.According to the theoretical parameters of the photographic lighting source module,the design of each component of the large energy multi-pulse laser source is completed,including the pump structure design,laser structure design and cooling system design.A laser homogenizing system is designed by using double array microlens and diffuser.The working parameters of the laser are tested,including pulse number,pulse width,pulse interval and pulse energy.The test results meet the technical requirements of multi-parameter fragment testing.Then,according to the theory of image acquisition module and the performance analysis of high-speed imaging sensor,the imaging devices that meet the needs of fragment testing are selected.The multi-parameter test time sequence model of intermittent fragment is established,and the working time sequence of the system is described.According to the theory of synchronization control module,the design of multichannel pulse output synchronization controller is completed by using FPGA technology,and the precision of synchronization control and synchronization performance are tested.The test results meet the technical requirements of chip testing.Finally,the ultra-high speed simulated fragments were used as the experimental object,and the pressure launching experiment of two-stage light gas gun was carried out on the simulated fragments.The calibrated velocity parameter of fragments was 4000m/s,and the size parameter was 2mm.Make experimental plan according to experimental purpose,including test purpose,test equipment,test method,test principle and test process.The multi-parameter testing technology was used to test the simulated fragment,and several parameters of the fragment were analyzed and summarized,including space coordinates,motion velocity,fragment size,velocity measurement error and velocity attenuation factor,which verified the feasibility of the fragment multi-parameter testing technology.