Error Weak Signal Processing Technology Of Velocity Coil Target

The coil target is used as the projectile velocity test equipment in the shooting range test.In this paper,when measuring small-caliber projectiles with a large-caliber coil target,the output signal of the coil target is very weak and it is mixed with the noise of the coil target.Overall scheme design of measuring small caliber projectile with large coil target,the weak signal processing method of the coil target is studied.Firstly,the magnetic dipole model of the coil target is analyzed,theoretically,the diameter of coil target is deduced.Relationship between induced electromotive force of coil target and influencing factors of coil,and the induced electromotive force of the coil target when the projectile is at different positions on the ballistic axis is analyzed,and the measurement model of the coil target is simulated and analyzed by Matlab and Ansys software.The effects of factors such as the physical parameters of the coil target and the measured projectile parameters on the induced electromotive force of the coil target are discussed.The winding method of the differential coil is used to wind the coil,which aims to further reduce the common mode noise of the coil target.The influence of the structure parameters of the coil target on the induced electromotive force is studied.The optimal structure parameter can effectively improve the stability of the coil target.The twisted pair winding method is used to wind the transmission line of the coil target,this is beneficial to shield the interference of external electromagnetic field on the signal transmission of coil target.Secondly,the matched filter processing method is used to filter the aliased signal of the coil target.It is verified through experiments that the matched filter processing method can extract the weak signal,and the subsequent coil target amplifying circuit is designed,and the coil target amplifying circuit is verified by the experiment the design requirements.Finally,an equivalent physical model for measuring small-caliber projectiles with a large coil target is developed,and the matching filtering method of the coil target is verified.It is obtained that the speed measurement error between the coil target and the standard light curtain target is no more than 0.6%.The output signal of the amplifying circuit of the coil target under different conditions is analyzed,the reason for the interference signal is obtained and the solution is researched.