| Magnetic field measurement technology is widely used in medical physical examination,prospecting,anti submarine and other industry and production.At present,foreign countries already have high-precision products available,but the country is still in the stage of in-depth study,and there is no particularly mature products in this field.In this paper,aiming at the characteristics of the output signals of the physical system,a high-precision cesium optical pump magnetometer information processing system is studied and implemented,which can be applied to the field of weak magnetic measurement.The main research work is as follows:In the overall scheme,this paper analyzes the working principle of the cesium optical pump magnetometer physics system firstly,and then summarizes and sums up the relationship between the Larmor frequency,the frequency of the signal outputted from the physical system,and the geomagnetic field.Then,based on the comparison of traditional frequency measurement method and cycle measurement method,the improved measurement scheme is proposed.The scheme improves the measurement accuracy while maintaining a wide measuring range.In hardware,this paper analyzes the hardware circuit design and optimization of several core parts of cesium optical-pump magnetometer information processing system,including direct frequency doubling circuit,mixer circuit,core circuit board,attitude sensor and positioning module.Optimization is as follows: By direct frequency doubling and using high precision clock sources such as rubidium atomic clock,the system obtains standard frequency signal with high precision,laying the foundation for the high precision measurement.By optimizing the design of filters and amplifiers in the mixer circuit,and using the necessary shielding measures,the noise and interference are reduced,and the stability and reliability of the system are improved.Through the independent design and integration of the whole system circuit,the system volume is greatly reduced,and becomes convenient to carry.Finally,the paper analyzes the principle of the attitude detection function in order to avoid the physical system entering the dead zone.In software,this paper analyzes the design idea and optimization of the software,which includes three parts: hardware logic,embedded software and upper monitor software.Innovation is as follows: Through the special design in shift operation achieved nearly floating-point arithmetic effect,the system realizes the calculation of direct digital synthesizer frequency control parameter without using floating-point kernel.Finally,all measurement work is finished in hardware logic,improving system processing speed and reliability.In order to deal with the problem that the physical system of cesium optical-pump magnetometer may enter dead zone,the system particularly use an attitude sensor module to measure the physical state data of the optical axis of the physical system,while using the Open GL graphics library in PC to draw three-dimensional state diagram based on QT SDK,providing convenience for users in remote monitoring.Through the integration of positioning module achieving the acquisition of geolocation information,it’s convenient for user to analysize geomagnetic field measurement data.Finally,after the completion of system design,the test results and analysis are given,and the whole system is tested.At last,the further optimization of the system is given. |
