• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.126-129
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• 2010

추진기관용 점화안전장치인 SAU에 적용 가능한 MEMS 관성 스위치를 고안하였다. 본 MEMS 관성 스위치는 일반적인 기계요소 설계 방식을 따라 설계하였으나 일반적인 MEMS 가속계와 다르게 목넘김 관성 스위칭 방식을 채택하여 일정 가속도 이상에서만 스위칭이 일어난다. 제작된 시료에 대한 검사 결과와 설계 데이터를 비교해 본 결과 관성 스위치의 구성 요소인 판 스프링 및 연성 힌지의 비선형요소에 의한 영향으로 인하여 설계된 스위칭 가속도 값과 근사한 차이가 유발됨을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권10호
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• pp.499-503
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• 2006

This paper deals with a new two dimensional clinometer based on dual axis micromachined accelerometers. The clinometer is a small and low-cost product, which is mainly developed to help golfers read easily the tilt of a putting green. First, this paper proposes the principle of two dimensional clinometer and also a calibration method with respect to the offset voltage and sensitivity of a accelerometer. Experimental results on the developed clinometer show that the proposed clinometer can provide useful information on the tilt angle and direction of an inclined plane.

• 한국구조물진단유지관리공학회 논문집
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• 제19권4호
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• pp.43-48
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• 2015

본 연구에서는 지진계 센서의 동적범위를 향상시키는 새로운 방법을 제안하였다. 먼저, 센서에 포함된 저주파수 대역 잡음을 ARMA(Auto Regresive Moving Average) 모델로 모델링하고 시스템 식별 방법으로 그 모델을 식별한다. 다음으로, 모델링된 잡음과 지진파 입력을 칼만필터 식에 포함하여 칼만필터에 의한 지진파입력을 추정한다. 제안한 방법을 새로이 개발된 MEMS 기반 3축 가속도 형태의 지진계에 적용하여 성능을 검증하였다. 시험 결과는 제안한 방법이 단순한 LPF(Low Pass Filter)를 사용한 경우에 비해 동적범위를 개선시킴을 보여준다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권1호
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• pp.58-66
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• 2005

Inertial-grade vertical-type and lateral-type differential resonant accelerometers (DRXLs) are designed, fabricated using one process and tested for navigational applications. The accelerometers consist of an out-of-plane (for z-axis) accelerometer and in-plane (for x, y-axes) accelerometers. The sensing principle of the accelerometer is based on gap-sensitive electrostatic stiffness changing effect. It says that the natural frequency of the accelerometer can be changed according to an electrostatic force on the proof mass of the accelerometer. The out-of-plane resonant accelerometer shows bias stability of $2.5{\mu}g$, sensitivity of 70 Hz/g and bandwidth of 100 Hz at resonant frequency of 12 kHz. The in-plane resonant accelerometer shows bias stability of $5.2{\mu}g$, sensitivity of 128 Hz/g and bandwidth of 110 Hz at resonant frequency of 23.4 kHz. The measured performances of two accelerometers are suitable for an application of inertial navigation.

• International Journal of Control, Automation, and Systems
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• 제5권1호
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• pp.35-42
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• 2007

This paper presents an INS(Inertial Navigation System) grade, surface micro-machined differential resonant accelerometer(DRXL) manufactured by an epitaxially grown thick poly silicon process. The proposed DRXL system generates a differential digital output upon an applied acceleration, in which frequency transition is measured due to gap dependent electrical stiffness change. To facilitate the resonance dynamics of the electromechanical system, the micromachined DRXL device is packaged by using the wafer level vacuum sealing process. To test the DRXL performance, a nonlinear self-oscillation loop is designed based on the extended describing function technique. The oscillation loop is implemented using discrete electronic elements including precision charge amplifier and hard feedback nonlinearity. The performance test of the DRXL system shows that the sensitivity of the accelerometer is 24 Hz/g and its long term bias stability is about 2 mg($1{\sigma}$) with dynamic range of ${\sigma}70g$.

• 한국기계기술학회지
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• 제13권4호
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• pp.93-99
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• 2011

This paper presents a new type of optical silicon accelerometer using deep reactive ion etching (DRIE) and micro-stereolithography technology. Optical silicon accelerometer is based on a mass suspended by four vertical beams. A vertical shutter at the end of the mass can only moves along the sensing axis in the optical path between two single-mode optical fibers. The shutter modulates intensity of light from a laser diode reaching a photo detector. With the DRIE technique for (100) silicon, it is possible to etch a vertical shutter and beam. This ensures low sensitivity to accelerations that are not along the sensing axis. The microstructure for sensor packaging and optical fiber fixing was fabricated using micro stereolithography technology. Designed sensors are two types and each resonant frequency is about 15 kHz and 5 kHz.

• Journal of Positioning, Navigation, and Timing
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• 제8권3호
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• pp.107-117
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• 2019

When a vehicle moves with a high rotation rate, it is not easy to measure the angular velocity using an off-the-shelf gyroscope. If the angular velocity is estimated using the extended Kalman filter in the gyro-free inertial navigation system, the effect of the accelerometer error and initial angular velocity error can be reduced. In this paper, in order to improve the navigation performance of the gyro-free inertial navigation system, an angular velocity estimation method is proposed based on an extended Kalman filter with an accelerometer random bias error model. In order to show the validity of the proposed estimation method, angular velocities and navigation outputs of a vehicle with 3 rev/s rotation rate are estimated. The results are compared with estimates by other methods such as the integration and an extended Kalman filter without an accelerometer random bias error model. The proposed method gives better estimation results than other methods.

• 디지털산업정보학회논문지
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• 제18권4호
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• pp.47-54
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• 2022

In this paper, MEMS embedded system design implemented the sensor events via analyzing the characteristics that dynamically happened to an abnormal status in power IoT environments in order to guarantee a maintainable operation. We used three kinds of tools in this paper, at first Bluetooth Low Energy (BLE) technology which is a suitable protocol that provides a low data rate, low power consumption, and low-cost sensor applications. Secondly LSM6DSOX, a system-in-module containing a 3-axis digital accelerometer and gyroscope with low-power features for optimal motion. Thirdly BM1422AGMV Digital Magnetometer IC, a 3-axis magnetic sensor with an I2C interface and a magnetic measurable range of ±120 uT, which incorporates magneto-impedance elements to detect the magnetic field when the current flowed in the power devices. The proposed MEMS system was developed based on an nRF5340 System on Chip (SoC), previously compared to the standalone embedded system without bluetooth technology via mobile App. And also, MEMS embedded system with BLE 5.0 technology broadcasted the MEMS system status to Android mobile server. The experiment results enhanced the performance of MEMS system design by combination of sensors, BLE technology and mobile application.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.79-79
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• 2000

In this Paper, the PC input device using MEMS gyros and accelerometer is newly developed, so that it can measure rotation rate and linear acceleration of the human body in space. In General, the human motion has 6 degree of freedom but 2 degree of freedom is enough PC monitor with 2D display. Therefore the simple method is proposed to achieve minimum degree of freedom. It is also applied to the PC mouse. This method can be expanded to the input device for internet set-top box or internet TV.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.91.6-91
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• 2002

$\textbullet$ Simulation of the effect of external vibration on optical disk pickups.$\textbullet$ Vibration effect is cancelled with aceeleration feedforward. $\textbullet$ MEMS accelerometers are small enough not to require any mechanical design modification. $\textbullet$ LQR, LQG, and SMC type controllers are designed. $\textbullet$ With the feedforward, transmissibility is reduced significantly. $\textbullet$ Time domain simulation confirms the performance enhancement. $\textbullet$ The resultant system shows excellent command following characteristics as well.