Research On The Influence Of On-Orbit Monitoring Sysyem Location By Acoustic Emission Signal Coupling Of Bumper And Cabin

With the development of space technology, more and more spacecrafts were launched in orbit. But the space debris environment has seriously deteriorated, it is difficult to orbit safely around the earth. At present, for space debris's diameter from 1cm to 10cm, human cannot accurately predict its orbit and there is no effective protection structure able to withstand their impact, therefore, an on-orbit monitoring system is needed to detect that the space debris impacts spacecraft. Beijing Institute of Structures and Environmental Engineering and Hypervelocity Impact Research Center of Harbin Institute of Technology jointly developed an in-orbit monitoring system based on acoustic emission technology, the prototype has been developed, then will enter the engineering phase. When space debris impact on the Whipple shield, the acoustic emission in the bumper will transmit through the support structure to the bulkhead and trigger the sensors on the bulkhead, then the precision of location will be interferenced, so this phenomenon must be studied.Aluminum projectile impacting protection structure model can simulate the space debris impacting on spacecraft, acoustic emission signal caused by the aluminum projectile impact protection structure model's front panel will transmit to the rear panel, The amplitude and frequency characteristic of interference acoustic emission signal was studied. A concept of interference time was proposed, the maximum interference time was determined . The amplitude and frequency characteristic between the interference signal and cabin's S0 mode signal were compared.Three conclusion was confirmed.Firstly, the frequency band between the two is coincidence, through the filter or the wavelet transform can't exactly remove the interference of acoustic emission signals;Secondly, the maximum amplitude of interference acoustic emission signal is smaller than the first peak of acoustic emission signal in the cabin, you can set a reasonable threshold to determine the arrival time of cabin acoustic emission signals.Thirdly,adding a layer of rubber gaskets between the front and support structure can significantly reduce the interference signal's amplitude and improve the accuracy of location. This measure has positive significance to practical on-orbit monitoring system.