|タイトル||*平成29年度中間年報 エネルギー・環境新技術先導プログラム 未踏チャレンジ２０５０ 周波数変調・積分型 MEMSジャイロスコープの開発|
|報告書年度||2017 - 2017|
|英文要約|| In this year, two types of MEMS resonators, an electromagnetic type ring resonator and an electrostatic type quad mass resonator, were designed and fabricated. In addition, the control system to realize a frequency modulated (FM) and whole angle (WA) gyroscope was constructed by using commercially available digital lock-in amplifier or an FPGA.
The electromagnetic type ring resonator which has two rings, one for resonator and the other for nulling the force, was designed by using FEM. The proposed method drastically reduces the stress at the anchor point, which might increases the Q-factor. The standard MEMS process was used and the resonator structure was successfully fabricated.
The electrostatic type quad-mass resonator was also designed and fabricated. Despite the structure of the device is much more complex than electromagnetic ring resonator, it is advantageous in terms of Q-factor and no external component such as permanent magnet.
For the operation of FM/WA gyroscope, a control loop consisting of a CW/CCW mode separator, numerical controlled oscillators (NCOs), PID controllers and digital filters is used. First of all, to demonstrate the FM/WA operation, commercially available digital lock-in amplifiers were used to construct the control loop. The experimental results using a commercially available ring type resonator well agreed with the theory, which indicate the gyroscope system was successfully worked as designed. The same control system was implemeted in a FPGA combined with AD and DA converters. The experimental result was essentially same as those using digital lock-in amplifiers. In addition, a mismatch compensation mechanism based on modification of driving amplitudes and phases was implemented and the mismatch of the resonator could be successfully compensated. Finally a virtual rotation method to avoid the angle locking phenomenon in WA gyroscope was implemented.