This paper reports an approach of in-operation temperature bias drift compensation based on phase-based calibration for a stiffness-tunable MEMS accelerometer with double-sided parallel plate(DSPP)capacitors.The tempe...This paper reports an approach of in-operation temperature bias drift compensation based on phase-based calibration for a stiffness-tunable MEMS accelerometer with double-sided parallel plate(DSPP)capacitors.The temperature drifts of the components of the accelerometer are characterized,and analytical models are built on the basis of the measured drift results.Results reveal that the temperature drift of the acceleration output bias is dominated by the sensitive mechanical stiffness.An out-of-bandwidth AC stimulus signal is introduced to excite the accelerometer,and the interference with the acceleration measurement is minimized.The demodulated phase of the excited response exhibits a monotonic relationship with the effective stiffness of the accelerometer.Through the proposed online compensation approach,the temperature drift of the effective stiffness can be detected by the demodulated phase and compensated in real time by adjusting the stiffness-tuning voltage of DSPP capacitors.The temperature drift coefficient(TDC)of the accelerometer is reduced from 0.54 to 0.29 mg/℃,and the Allan variance bias instability of about 2.8μg is not adversely affected.Meanwhile,the pull-in resulting from the temperature drift of the effective stiffness can be prevented.TDC can be further reduced to 0.04 mg/℃through an additional offline calibration based on the demodulated carrier phase representing the temperature drift of the readout circuit.展开更多
The effects of the E × B drift and ballooning-like transport on the edge plasma in EAST tokamak are investigated with a simplified fluid model. The simulation results show that the E × B drift and ballooning...The effects of the E × B drift and ballooning-like transport on the edge plasma in EAST tokamak are investigated with a simplified fluid model. The simulation results show that the E × B drift and ballooning-like transport affect the plasma behavior. When the toroidal field is reversed, at the low field side the density is much larger and temperatures （both electron and ion） are lower, and the profiles of the density and temperatures become more symmetric. With the ballooning-like transport considered, the spatial ballooning-like distribution at the low field side is not very important, but the magnitude affects the ratios of the inner/outer particle flux and energy as well as the E × B drift. At the top of the scrape-off layer, the Mach number exceeding 0.3 for the normal toroidal field and approaching 0.2 for the reversed toroidal field in the simulation are obtained when the drift and ballooning-like transport are included in the model.展开更多
基金The work is supported by the Grant of the National Natural Science Foundation of China(Grant No.62104211).
文摘This paper reports an approach of in-operation temperature bias drift compensation based on phase-based calibration for a stiffness-tunable MEMS accelerometer with double-sided parallel plate(DSPP)capacitors.The temperature drifts of the components of the accelerometer are characterized,and analytical models are built on the basis of the measured drift results.Results reveal that the temperature drift of the acceleration output bias is dominated by the sensitive mechanical stiffness.An out-of-bandwidth AC stimulus signal is introduced to excite the accelerometer,and the interference with the acceleration measurement is minimized.The demodulated phase of the excited response exhibits a monotonic relationship with the effective stiffness of the accelerometer.Through the proposed online compensation approach,the temperature drift of the effective stiffness can be detected by the demodulated phase and compensated in real time by adjusting the stiffness-tuning voltage of DSPP capacitors.The temperature drift coefficient(TDC)of the accelerometer is reduced from 0.54 to 0.29 mg/℃,and the Allan variance bias instability of about 2.8μg is not adversely affected.Meanwhile,the pull-in resulting from the temperature drift of the effective stiffness can be prevented.TDC can be further reduced to 0.04 mg/℃through an additional offline calibration based on the demodulated carrier phase representing the temperature drift of the readout circuit.
基金supported by National Natural Science Foundation of China(No.10675129)
文摘The effects of the E × B drift and ballooning-like transport on the edge plasma in EAST tokamak are investigated with a simplified fluid model. The simulation results show that the E × B drift and ballooning-like transport affect the plasma behavior. When the toroidal field is reversed, at the low field side the density is much larger and temperatures （both electron and ion） are lower, and the profiles of the density and temperatures become more symmetric. With the ballooning-like transport considered, the spatial ballooning-like distribution at the low field side is not very important, but the magnitude affects the ratios of the inner/outer particle flux and energy as well as the E × B drift. At the top of the scrape-off layer, the Mach number exceeding 0.3 for the normal toroidal field and approaching 0.2 for the reversed toroidal field in the simulation are obtained when the drift and ballooning-like transport are included in the model.
