Research On High Precision Geomagnetic Directional Magnetic Field Interference Correction Technology

With the development of science and technology,orientation technology is becoming extensive.It plays an important role in sightseeing system,aviation,aerospace and navigation.As a fully autonomous orientation technology,geomagnetic orientation has the advantages of accuracy,reliability,concealment and applicability,which is of great significance to national defense and life.It is vulnerable to soft and hard magnetic interference in the external environment as well as its own error factors,leading to increased orientation error.The purpose of this paper is to develop a high-precision geomagnetic orientation hardware platform,compensate the geomagnetic sensor with algorithm,and calculate high-precision attitude.Firstly,the interference and error correction algorithms of geomagnetic sensors are studied.The sources of interference and error of geomagnetic sensors are analyzed.The error correction model is established.The parameters of the model are solved by sliding mean filter,Newton iteration method and total least square method.Then a high precision attitude calculation algorithm is realized.The initial values of attitude angles are solved by using geomagnetic sensors and accelerometers,and then quaternions are solved by combining gyroscopes to update attitude angles and reduce orientation errors.According to the requirement of the algorithm,a high precision hardware platform for geomagnetic orientation is designed.The hardware platform mainly includes STM32F411 microprocessor,RM3100 geomagnetic sensor and BMI160 inertial measurement unit.It also carries data communication module and power-off storage module,which is portable and low power consumption.The software part completes the initialization of each module,realizes the data acquisition and processing program,communication program,data storage program and geomagnetic orientation algorithm.Finally,the whole function of the high precision geomagnetic orientation platform is tested.After testing,the hardware and software of the platform have achieved the expected functions.The sensor can acquire and process the corresponding data stably,and can correctly realize the functions of data communication and storage.The correction algorithm can effectively compensate the interference and error of the geomagnetic sensor,correct the distortion and migration of the triaxial geomagnetic data,and the orientation algorithm can correctly control the attitude angle and the error in a small range.