Research On Detection Technology And Application Of Magnetic Field Signal In Bore

With the development of high precision ammunition technology,the accuracy requirements for timing starting point of electronic time fuze is getting higher and higher.Based on the geomagnetic detection module in the small caliber self-measuring velocity and correcting electronic time fuze,the detection technology and application of magnetic signal in bore were studied to provide a design reference for finding the timing starting point of high precision electronic time fuze.Firstly,the physical process of ammunition launching was introduced.The geomagnetic field in bore during the launching process and the magnetic field produced by the burning of the propellant were analyzed.In the aspect of geomagnetic field,the magnetic shielding effect of gun barrel in axial and radial direction was analyzed through calculation and dimensional simulation.In terms of the magnetic field generated by the propellant burning,the characteristics of the magnetic field and the shielding effect of the projectile on the magnetic field were analyzed through experiments at the firing range and software simulation.Then,the missile-carrying storage test system was designed to collect and store geomagnetic detection module signal in the process of ammunition launching in real time.A detection method based on the superimposed magnetic field was proposed through simulation.The method is to place the excitation coil for generating magnetic field at the known position on the target track.The muzzle-leaving time of projectile was derived by determining the moment of the projectile flying through the center of the superimposed magnetic field,to provides a time base for the analysis of geomagnetic detection module signal in bore.Finally,the recovery experimental platform in the firing range was set up and the experiments were carried out.The acquisition and storage of signals during the process of ammunition launching were finished.The muzzle-leaving time of projectile was obtained by the frequency analysis method to be applied to the solution of the relative activation time of the chemical battery in fuze and the analysis of the geomagnetic detection module signals in bore.It was found that the maximum value of relative activation time of chemical battery in fuze is 3.98ms by analysing,while the maximum value of starting point of geomagnetic detection module signal in bore is 0.321ms,so it can be used as the timing starting point of electronic time fuze.