Title :
Digital-controlled MEMS vibratory-beam-accelerometer
Author :
Fujita, Takayuki ; Okada, Hiroki ; Iguchi, Kaoru ; Maenaka, Kazusuke
Author_Institution :
Grad. Sch. of Eng., Univ. of Hyogo, Kobe
Abstract :
This report provides a MEMS (micro-electromechanical systems) vibratory beam accelerometer (VBA) having a digital control system. The device structure with size of 5 times 5 mm2 includes a frame, heavy mass, thick suspension beams, and thin vibrating beams made of silicon. The VBA measures acceleration using the resonant frequency change of the supporting beams, which are designed to provide little resistance to movement along the sensitive axis and stiff resistance on the off-axis. This provides low off-axis sensitivity and high shock survivability. In this study, we designed a fully digital PLL (phase-locked loop) circuitry in a FGPA (field programmable gate array) based hardware controller. By Allan deviation, we proved that our system has a resolution of 34 muG Hz-1/2 for a device operating at 1 mTorr.
Keywords :
accelerometers; digital control; digital phase locked loops; field programmable gate arrays; micromechanical devices; physical instrumentation control; vibrations; FGPA; MEMS vibratory-beam-accelerometer; digital PLL circuitry; digital control system; field programmable gate array; high shock survivability; micro-electromechanical systems; phase-locked loop; resonant frequency; Acceleration; Accelerometers; Digital control; Electrical resistance measurement; Frequency measurement; Microelectromechanical systems; Micromechanical devices; Phase locked loops; Phased arrays; Silicon; FPGA; MEMS; VBA; digital PLL; vibratory beam accelerometer;
Conference_Titel :
Automation Congress, 2008. WAC 2008. World
Conference_Location :
Hawaii, HI
Print_ISBN :
978-1-889335-38-4
Electronic_ISBN :
978-1-889335-37-7
