Method and device for eliminating offset of fluxgate magnetometer

An offset data acquisition device of a fluxgate magnetometer, wherein:

• the offset data acquisition device of the fluxgate magnetometer is applied to the fluxgate magnetometer, the fluxgate magnetometer comprises:
• a probe, a the feedback module, an excitation module, and a sensing module;
• a first analog switch is provided between the probe and the feedback module, the second analog switch is provided between the probe and the excitation module, and a third analog switch is provided between the probe and the sensing module;
• the fluxgate magnetometer further comprises a comprehensive controller wherein:
• a timer module, configured in the comprehensive controller, controls the first analog switch, the second analog switch and the third analog switch to change the directions within a preset period to obtain the eight switch direction combinations between the first analog switch, the second analog switch and the third analog switch;
• a data acquisition module, configured in the comprehensive controller, acquires a magnetic field measurement data corresponding to the each of the switch direction combinations;
• and the magnetic field measurement data comprises an x-axis magnetic field measurement data, a y-axis magnetic field measurement data and a z-axis magnetic field measurement data;
• and
• an offset calculation module, configured in the comprehensive controller, acquires the offset data based on influence factors of the offset and the magnetic field measurement data within the preset period, wherein the influence factors include a residual magnetism of the probe and the environment, a coupling leakage of the excitation signal in the probe, the parasitic capacitance effect of the probe, a distortion of the probe induced signal, the imbalance of the induced signal processing circuit and the imbalance of the feedback signal processing circuit.