Data Acquisition And Error Calibration Of Triaxial Fluxgate Sensor Based On PIC

Since the 1930s,fluxgate sensors have been used for measuring magnetic fields.with the development of electronic science and technology,the performance of the fluxgate sensor has been greatly improved.At the same time,as the electronic system that data acquisition of the fluxgate sensor,it gets more and more people's attentions,and also puts forward higher requirements.For example,high precision.Miniaturization of Electronic Systems?low-power.reliable and so on?In recent years,magnetic fluxgate sensors are widely used in aerospace engineering,military weapons,space magnetic field measurements,geomagnetic navigation,geological prospecting,vehicle engineering,material nondestructive testing,bio-magnetic measurement and other fields.Compared with other types of sensors,the fluxgate sensor has the advantages of high sensitivity,high resolution,high stability,small size,economical and practical,simple structure,magnetic fluxgate sensors have great advantages in these fields.Abroad,the magnetic fluxgate sensors are relatively mature and high level,and their products achieve miniaturization,high precision,commercialization but high price.and the domestic development of magnetic fluxgate sensor mainly used in ore magnetic field measurement,satellite attitude control and so on,most of the products failed to form serialization and commercialization,can not operate independently.In this paper,a high-precision data acquisition module based on high-precision analog digital converter AD7192 and high performance dsPIC33F128GP802 MCU is designed,and the error analysis of magnetic fluxgate sensors,which greatly improves the accuracy and stability of the data.Firstly,this paper briefly introduces the research background of magnetic sensors and the research actuality at home and abroad,in order to have a general understanding of the various types of magnetic sensors,thus,there is a macroscopic concept of the magnetic fluxgate sensors and the current high-precision acquisition technology.Secondly,the theory and operation principle of fluxgate sensors are introduced.On this basis,the magnetic fluxgate sensors are analyzed,and the design requirements of high-precision data acquisition are developed.Thirdly,the hardware circuit design of data acquisition module.Aiming at the requirement of data acquisition module,the chip selection is completed and the chips are briefly introduced,the main Circuit module has MCU module,AD7192 conversion module and CAN module.In the design of each module,the anti-interference design should be carried out as far as possible to achieve high precision and high stability acquisition target.After completing the schematic design of each circuit module,the PCB board design of the whole data acquisition system is carried out.Further,we make a careful analysis and calculation of measurement error in three-axis fluxgate magnetometer caused by non-orthogonality,different sensitivity between three axis and zero-shift of three-axis.Then a three-axis fluxgate instrument error correction model is established by analyzing the nature of it.and the optimization of output results is achieved by the singular value analysis and the calculation of the simplex method.On this basis,the modification of the magnetic Fluxgate sensor under the condition of motion is discussed,and the transformation of the two-dimensional state under three-digit condition is realized.Finally,the whole data acquisition system is summarized,and the design of high precision data acquisition system needs further improvement.