Characterization and control of a high-Q MEMS inertial sensor using low-cost hardware

J. A. Gregory, J. Cho, K. Najafi
2012 Proceedings of the 2012 IEEE/ION Position, Location and Navigation Symposium  
We propose a high-performance, low-cost system for control and characterization of MEMS rate and rate-integrating gyroscopes and other resonant sensors. MEMS gyroscopes, some accelerometers and clocks utilize mechanical resonators. Highquality factor, low-frequency resonator devices with damping time constants from seconds to several minutes pose special characterization challenges. The proposed system uses the commercial "USRP" software defined radio (SDR) hardware and open source GnuRadio
more » ... ware as a platform for the proposed characterization and control system. For characterization of resonators, we developed software to perform dual channel swept-frequency gain-phase analysis, impulse response real-time spectral analysis, and ring down testing which achieve performance comparable to dedicated commercial hardware. To highlight the capabilities of the characterization tools, we implemented an automatic mode matching algorithm in the software. The same hardware is used for control of gyroscopes in either rate or rate integrating modes. We present here two control schemes; a rate-only control implemented entirely in the FPGA of a USRP1, and a hybrid software/firmware control which is capable of rate and rateintegrating operation. Experimental results of characterization, automatic tuning and rate-mode operation of a rate and rateintegrating MEMS gyroscope are presented to demonstrate the viability of the proposed system.
doi:10.1109/plans.2012.6236886 fatcat:fp5co53a5rcsjhh75bu5wmfmze