Research On Measuring Device Of Angular Velocity Of Projectile Based On Geomagnetic Sensor

With the development of modern war, precision strike has become a trend, and the trajectory correction technology is developed on the basis of conventional ammunition. How to acquire projectile attitude angular velocity is the key technology of trajectory correction in real time. In this paper, measuring device of angular velocity of projectile based on the three axis digital geomagnetic sensor is studied, which is based on the law of the angular motion of the projectile, the hardware and software of the system, the Kalman filter algorithm and the hardware in the loop simulation.Firstly, this paper introduces the composition and characteristics of the earth’s magnetic field as well as the mathematical model of the earth’s magnetic field, which is the theoretical basis of the study of geomagnetic navigation. On the basis of this, the detection principle of the magnetic sensor is introduced, and the magnetic resistance sensor is selected as the core component of the geomagnetic measurement module.Secondly, the law of angular motion and coordinate transformation are analyzed, and the mathematical model of geomagnetic measurement is established, and the geomagnetic component of projectile is obtained. The angular velocity filtering algorithm is studied, and the solution of angular velocity is realized by using the extended Kalman filter. According to the mathematical model, the solution algorithm and the exterior ballistic theory, the Matlab/Simulink simulation model is established, which is used to produce the geomagnetic simulation data and the filter algorithm.Again, the measuring device of angular velocity of projectile based on geomagnetic sensor is designed, for accuracy and real-time requirements, HMC5983 triaxial digital geomagnetic sensor and TMS320F2808 fixed-point DSP were selected as the core device of measuring device. In the aspect of hardware circuit design, geomagnetic measurementmodule, DSP and its peripheral circuit, communication module and power supply module are mainly studied; in the aspect of software design, mainly in the serial communication, digital filtering and internal algorithms processing to do the research.Finally, on the hardware in loop simulation of geomagnetic type measuring device of projectile angular velocity, to study the structure and working principle of semi physical simulation system, using trajectory simulation software to calculate the magnetic field simulation signal andgeomagnetic measurement module to sensitive 3-axis geomagnetic component.Based on the measured data, the projectile angular velocity is obtained by using the extended kalman filter, and the error is in the allowable range, which proves the feasibility of measuring device.