Browsing by Author "Chi, Chien-Yu"

Now showing 1 - 4 of 4

A Gyroscope Control System for Unknown Proof Mass and Interface Circuit Errors
(2010)
Chi, Chien-Yu
;
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a novel approach that can compensate errors resulting from the imperfections of mechanical structures and interface circuits for MEMS gyroscope systems. The mechanical structure errors discussed in this paper contribute to unknown proof mass, spring constants, damping coefficients, and existence of cross-axis resilient/damping forces. The interface circuit errors include: mismatch of differential capacitors, parasitic capacitance, offset voltage of operation amplifiers, and circuit noise. Different from most of existing researches, the proposed method has the following features: (1) the mechanical structure imperfections and interface circuit errors are compensated simultaneously using control techniques; (2) the mass of the proof mass can be unknown. This approach is verified on two types of gyroscope designs by numerical simulations. Simulation results indicate that, under those imperfections, the proposed method can obtain correct angular rate within 80 milliseconds.
Compensation of Interface Circuit Errors for MEMS Gyroscopes Using State Observers
(2008)
Chi, Chien-Yu
;
Peng, Yen-Pin
;
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a novel approach that can compensate the error resulting from interface circuits for MEMS gyroscopes. Different from most of existing researches on gyroscopes wherein the interface circuits are either assumed to be ideal or optimized individually, this approach uses state estimation techniques to compensate the errors resulting from interface circuits and mechanical structure uncertainties, and to obtain correct angular rates for gyroscope systems. In a simulation case where the imperfections of interface circuits include: offset voltages of the operational amplifiers (3 mV and drifting with time), the parasitic capacitance (2 PF), and the measurement noise (white noise, 0.5 mV), the proposed method can estimate the angular rate correctly with an estimation accuracy of 8 x 10(-4)rad/sec.
MEMS Gyroscope Control Systems for Direct Angle Measurements
(2009)
Chi, Chien-Yu
;
Chen, Tsung-Lin
;
交大名義發表
;
National Chiao Tung University
This paper presents a control algorithm for vibrating gyroscopes so that they can directly measure the rotation angle without integrating the angular rate. In most gyroscope systems, the rotation angles were obtained by integrating the angular rate, thus suffer from the error accumulation problem. Only a few papers reported that they could compensate the imperfect dynamics in gyroscopes and obtain the rotation angle directly. However, they either required a calibration phase prior to the normal operation or their stability was not theoretically proven. This paper proposes a one-step control algorithm so that imperfection compensation and angle measurement can be done simultaneously. In a demonstrating case, the mechanical structure uncertainties caused 10%similar to 20% parameter variations in a gyroscope system; the signal are contaminated by zero-mean white noise with the PSD of 2.3 x 10(-15) (ms(-1)) / H z; the angular rate to be measured is 4sin(2 pi x 40t) rad/sec. The proposed algorithm can obtain the rotation angle with an accuracy less than 0.5 degree.
Single-stage vibratory gyroscope control methods for direct angle measurements
(2011-05-01)
Chi, Chien-Yu
;
Chen, Tsung-Lin
;
機械工程學系
;
Department of Mechanical Engineering
This paper presents a control algorithm that can compensate for imperfect dynamics of vibrating gyroscopes. The compensated gyroscope dynamics can directly measure the rotation angle without integrating the angular rate. The direct angle measurement approach is promising because it is exempt from the error accumulation problem. However, using control methods to compensate for imperfect dynamics for the direct angle measurement is very challenging work, and very few control algorithms were reported to achieve that. Different from existing approaches, the proposed method has the following advantages: it requires the measurements of either the proof mass velocity or position, it does not require a calibration phase prior to normal use, and it compensates different types of imperfection even when the proof mass of a gyroscope is unknown. In a demonstration case, imperfections cause system parameters 20% deviated from their designated values; the measured signals are the proof mass velocities and contaminated by zero-mean white noise with a noise level of 0.1% full scale output (FSO); the angular rate to be measured is 200 sin(2 pi x 10t) deg s(-1). The proposed algorithm can compensate for those imperfections and achieve an angle measurement accuracy of 0.23 degrees.