Magnetoresistive Sensor Roll Angle Calibration And Optical Communications Data Transmission

The characteristics of the common-used sensors for the magnetic field measuring are analyzed. Then the advantages of the geomagnetic field measuring with the magneto resistive sensors according to the theory about the geomagnetic field model and the relative traits are introduced. By comparing the domestic and international researches on the magneto resistive sensors, the primary interferences of magneto resistive sensors are given when used in the magnetic field measurements, and the common methods used for the interferences eliminating are summarized. Besides, in the absence of the outside interferences, the test principle and correctness of the test circuit are proved. According to the experimental results, when the black box installed in the inside cartridge case, problems occurred in the process of attitude angle calibration are given.The magnetic field distribution within a metal projectile is analyzed via the three-dimensional integration method, and the results are obtained experimentally. Based on both the theory and experiments, the reasons for the problems in the experiment are given and the best location of the reluctance sensor inside the projectile are obtained, too. The characteristics of the black box are studied experimentally when used for magnetic field measurements; the stability of the test results about the black box under different locations is analyzed; and the environmental impaction is explained. According to a number of different attitude angles of the black box, the accurate mode for calibration on the cartridge attitude angle is given. The accuracy of the attitude angle calibration model is proved experimentally, while errors of test results are analyzed.The communication transmitting and receiving circuits in the visible light range are designed. Furthermore, the advantages of the visible light communication are given. Connecting the optical communication system and the output port of the black box data, the feasibility and stability of the optical communications are proved via the static tests. The dynamic tests of the optical communication system putting on the projectile body are done, realizing the wireless communication between the black box and computers. The main disturbance of visible light communication is summarized and methods used for eliminating ground noise are given.