【摘要】 研究了基于扭摆式结构的谐振式磁强计及其激振与测控系统,设计了扭摆式谐振磁强计的基本结构,其对称式结构能够抑制加速度对磁场检测的干扰.设计了L形梁来释放加工过程中的应力,推导了开环系统和闭环系统的传递函数,通过初步参数设计,对扭矩随线圈匝数的变化进行了仿真,并介绍了基于对被测信号进行调制和同步解调的电容检测原理.结果表明,该谐振式MEMS磁强计灵敏度和分辨率高,多匝线圈方案使器件灵敏度大幅度提高,10匝线圈时的扭矩是单匝线圈的8倍,磁强计分辨率优于30 nT.更多还原

【Abstract】 A torsional resonant magnetometer and its excitation,signal detection and control systems were studied.First,the basic structures of the torsional resonant magnetometer were designed with the characteristic of symmetrical structure,which could restrain the interference of acceleration to the magnetic field measure-ment.Furthermore,a torsional structure including four L beams was proposed to release the stress in microma-chining process.Thereafter,both open-loop and closed-loop transfer functions of the system were deduced.The curve of the moment generated by Lorentz force with the number of coils was also simulated based on the primary design of the structure parameters.Finally,the principle of the capacitance detection was elaborated in which the measured signal was modulated and synchronously demodulated.The simulation result indicates that the resonant MEMS magnetometer has the advantage of high sensitivity and resolution and its sensitivity is effectively improved by applying the multiple-coil scheme.The moment produced by 10 coils is 8 times that of only 1 coil.The resolution of the designed magnetometer is better than 30 nT.更多还原