Experimental Study On The Positioning Of Space Debris Impact Source

The study of ultra-high-speed impacts of space debris is particularly important for the increasingly frequent space debris impacting spacecraft events.As the spacecraft encounters the impact of space debris damage and even disintegration events are increasingly frequent,the research on space debris in-orbit sensing technology puts forward higher requirements.In order to cope with the threat of space debris,the large-volume debris is mainly in the form of evasion.The detection of small-volume space debris is difficult,and the threat of space debris is mainly dealt with by installing a protective layer.However,due to the level of technology,space debris impact events are still unpredictable,and spacecraft still face serious threats.The location of the space debris impact source can effectively improve the spacecraft's sensing ability,and provide a guarantee for the impact damage assessment and post-repair damage.But,from the current research results,the space debris impact source location has the problem of low positioning accuracy and long positioning time,and it is necessary to continue research work on this issue.Based on the above research background,this paper takes the positioning of super-high-speed impact source as the research object,and uses the two-stage light gas gun loading system to drive the aluminum spherical projectile to simulate the space debris impact target plate.The experimental research on how to calculate the collision source coordinates in real time is carried out.as follows:(1)Using the two-stage light gas gun loading system and the positioning system based on the stacked piezoelectric effect of two-dimensional PVDF film,the experiment of colliding the two-dimensional PVDF piezoelectric film at different collision speeds was carried out.Based on the piezoelectric effect and depolarization effect of PVDF film,the test system is established and the voltage signal is extracted.The plane rectangular coordinate system composed of strip PVDF is used to accurately locate the space debris collision source.The experimental results show that the piezoelectric effect of the two-dimensional PVDF film based on orthogonal stacking can locate the coordinates of the impact source,and the flight velocity and incident angle of the space debris can be determined by installing a double-layer PVDF film at a certain distance.(2)Using LABview graphical language programming platform and NI data acquisition card to establish a high-speed signal real-time acquisition system,based on LABview's unique programming language to establish a visual interface.The visual interface includes a sampling control module,a positioning coordinate display module and a waveform signal display module,where in the positioning coordinate display module and the two-dimensional PVDF positioning physical target one-to-one correspondence,the intersection of the coordinate system serves as an impact point.The experimental results show that the system can accurately locate the impact source.The experimental results show that the LABview-based impact source positioning system has real-time positioning capability,which can effectively implement real-time acquisition and processing of impact signals.(3)The acoustic emission full information acquisition platform was established,and the secondary light gas gun loading experiment was carried out.According to the propagation law of the acoustic emission signal,the collision source coordinates were calculated based on the geometric relationship of the acoustic emission signal sensor position.The signal is analyzed by wavelet transform principle,and the relationship between the initial velocity of the projectile and the energy of the high frequency band of the acoustic emission signal is described by extracting the energy value of the characteristic frequency band of the acoustic emission signal.The experimental results show that the acoustic emission plane positioning technology can realize the accurate positioning of the plane impact point,and there is a linear relationship between the signal propagation distance and the acoustic emission characteristic parameters.The wavelet transform principle can effectively improve the positioning accuracy.