【摘要】 提出了一种利用高斯噪声和弱正弦信号共同驱动的新型时间差型磁通门传感器.根据软磁材料双稳态特性及其Fokker-Planck方程推导了跃迁率的表达式.利用数值仿真的方法,研究了跃迁率和外磁场、激励磁场、噪声强度之间的关系.通过将周期变化的跃迁率信号转换为方波信号,建立了方波高低电平时间差与外磁场之间的关系,并推导了传感器灵敏度的表达式.研究表明,在一定的偏置磁场下,传感器灵敏度与激励磁场的幅值以及频率成反比,量程和激励磁场的幅值成正比.对所设计±10.7A/m量程的传感器样机进行了测试,传感器最小灵敏度为9.8696 ms/(A/m),可用于准静态微弱磁场的检测.更多还原

【Abstract】 A novel time-difference fluxgate sensor with weak sinusoidal and Gauss noise excitation is presented in this paper.Expression of the transition rate is derived according to the bistable peculiarity and the Fokker-Planck equation of the soft magnetic material. Relationships among transition rate, external magnetic field, amplitude of the excitation field,and noise intensity are discussed through numerical simulation. By converting the periodic transition rate signal to the square signal, the time difference between the high level and the low level of the square signal can be related with the external magnetic field. And the expression of the sensor’s sensitivity is derived. Simulation results show that the sensitivity is inversely proportional to the amplitude and frequency of the excitation magnetic field, and the measuring range is proportional to the amplitude of the excitation magnetic field. Experiments have been carried out on a fluxgate prototype with a measuring range of ±10.7 A/m. The minimum sensitivity could achieve 9.8696 ms/(A/m), and the novel time-difference fluxgate can be of great interest in the detection of quasi-static extremely weak magnetic field.更多还原