Research On Penetration Angle Measurement Technology Of Magnetic Detection

In conventional warfare,in order to be able to maximally strike enemy's important military protections buried in steel armors and reinforced concretes,intelligent hard target penetrating weapons are mainly used.It is required that the penetrating bomb must have the ability to penetrate hard targets.Most of the researches on penetrating projectiles penetrating hard targets are based on vertical penetration.However,in practical applications,penetrating projectiles are not only subject to longitudinal resistance to reduce the velocity,but also subject to lateral resistance causing the projectile to tilt.Penetrations of hard targets are usually in an oblique form.When oblique penetrating happens,if the penetration angle is too large,the projectile will become unstable,and even a bouncing can occur,which will prevent the penetrating projectile from detonating at a predetermined number of layers and reduce the maximum damage effect on the target.However,the existing methods of measuring the penetration angle are all limited to "external measurement methods" such as high-speed camera or studying the height difference of the bullet hole position.It is not possible to obtain the penetration angle change of the penetrating bullet at an oblique penetration in real time.Consindering that no current technology can actively measure the penetration angle in real time,in this dissertation,a penetration angle measuring method based on magnetic detection is studied.Main researches include the following aspects:1.A penetration angle measurement method based on magnetic detection is proposed.A single piece of magnet is placed on the inner axis of the fuze to establish a rotationally symmetric magnetic field environment,and a high-precision magnetic detector is installed also in the fuze for the real-time magnetic monitoring.When the penetrating projectile penetrates a hard target with magnetic substances obliquely,magnetic field inside the projectile will no longer be symmetric about its center axis,resulting in a magnetic field deflection angle,which changes accordingly with the penetration angle.By measuring the magnetic field deflection angle,and considering the numerical relationship between the penetration angle and the magnetic field deflection angle,accurate measurement of the penetration angle can be achieved.2.According to the proposed principle and method for the penetration angle measurement based on magnetic detection,a numerical model of the spatial magnetic field distribution of the magnet is first established,and the finite element analysis software ANSYS is used to further analyze the geometric model of the penetrating projectile and the penetrating target.The geometric models for different projectile positions and peneration angles are simulated and calculated,the numerical relationship between the penetration angle and the magnetic field deflection angle is determined,and the environmental adaptability and the situation of obliquely penetrating a two-layer target are simulated.3.A hardware circuit and its software for the magnetic-detecting penetration angle measurement is designed,which include a reference power supply circuit,a magnetic fieldacquisition circuit based on a triaxial magnetoresistive sensor,a set / reset circuit,an operational amplifier circuit and an ARM-based micro-control processing circuit.Through the detection of the geomagnetic field,it is proved that the hardware circuitcan work properly.4.A simulation installment is designed to perform static hardware-in-the-loop simulation experiments.Based on the relative distance between the magnet and the installed magnetic detector during the simulation,a simulation fuze device was designed,and the target net was simulated using a reinforced mesh to perform a static half-physical simulation experiment.The experimental results were proved to be consistent with the simulation results.The penetration angle can be characterized by measuring the deflection angle of the magnetic field.