실시간 동적 GPS를 이용한 IMU 센서의 오차특성 분석

이은수(Lee, Eun Soo) 한국지적정보학회 2014 한국지적정보학회지 Vol.16 No.1

본 연구는 전통적 지상측량 방식이 접근하기 힘든 공간 및 구조물에 대한 위치정보를 가격이 저렴하면서도 크기가 작은 관성센서를 이용하여 취득하기 위한 기초연구이다. 이를 위해서 관성센서를 이용한 위치정보취득 시스템 개발과 현장 적용 실험이 수행되어야 한다. 위치정보는 관성센서만으로 얻어져야 하나 정확도 검증을 위한 테스트 베드 설치의 어려움 때문에 실시간 동적 GPS를 이용한 동시관측으로 테스트 베드를 대신하고 이로부터 관성센서의 특성을 파악하는 것이 본 연구의 목표이다. 개발된 시스템에 대한 현장 실험은 도로에서 총 23회, 철로에서 5회 수행되었다. 직선 도로의 경우 대부분 Network RTK의 성과와 비슷한 양상을 보이나 곡선으로 바뀌면서 관성센서의 안정도에 따라 계속 휘어지는 경우도 발생하였다. 넓은 공터에서 차량을 자유롭게 이동시킨 경우는 차량의 궤적과 비슷한 양상을 보여주고 있으나 실제로는 최대 5m까지 Network RTK 성과와 편차를 보이는 경우도 있었다. 철로의 경우 직선에 대해 매우 안정적인 모습을 보여주고 있으나 곡선으로 접어들면서 곡률반경이 심하게 감소하고 있다. 본 연구에서 200m 이하의 짧은 구간에서 외부의 충격을 최소화 할 경우 관성센서로 취득한 위치 정보는 충분히 보정되어 이용할 수 있는 수준이었으나, 구간이 길어질 경우 관성센서의 각속도 오차 누적으로 인해 만족스럽지 못한 결과를 얻었다. 특히, 직선에서 곡선으로 이동하면서 관성센서의 각속도 역시 변하게 되는데 한 번에 변하지 않고 계속적으로 각속도에 영향을 주어 오차가 커지는 것으로, 이에 대한 영향을 어떻게 줄이느냐에 대한 연구가 추후 필요하다고 사료된다. This study is a basic research to acquire a location information of space and structures that are not easily accessible by a traditional ground survey method utilizing small and inexpensive inertial sensors. To this end, a development of inertial sensor based location information acquisition system and a field application testing have to be performed. The location information has to be acquired using only inertial sensors; however, for the difficulty in installing a test bed for accuracy validation, simultaneous observation through a dynamic GPS was used for the test bed instead. It is the goal of this study to identify the characteristics of the inertial sensor based on the result. The developed system was field tested on the road total of 23 times and 5 times on the railway. For a straight road, the pattern was similar to the performance of Network RTK, but some continuous curvature was observed depending on the stability of inertial sensor when road changed to a curved line. Similar pattern to the trajectory of vehicle was observed when vehicle was moved freely on a wide open space, however, in reality, there were cases where the deviation of up to 5m in comparison with the Network RTK performance was observed. In the case of rail, it shows a very stable posture on straight line; however, as it enters into a curved rail, the turn radius of curvature is being severely reduced. In this study, location information obtained from the inertial sensor in a short interval of less than 200m can be used with sufficient calibration, but as the longer the interval becomes, the outcome was not satisfactory due to the accumulated angular speed error of the inertial sensor. In particular, the angular velocity of the inertial sensor changes as the line changes from a straight to a curved line; it does not change at a time, but rather changes continuously, thereby influencing the angular velocity to have a bigger error. Further studies on how to reduce the influence on angular velocity is necessary.

MEMS 관성센서를 이용한 차량 자세인지 시스템

이정훈,김기택 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

This study has shown the system acquiring information of vehicle posture and rotational direction to be used by the interlock with GPS Navigation system with MEMS inertial sensor(acceleration sensor and angular velocity sensor) and geomagnetic sensor. By using acceleration sensor like accelerometer this study was to know whether the vehicle was moving upward or downward by acquiring the information of pitch for vehicle during driving. Based on this information this was used to judge it fast whether the vehicle enter to elevated highway, uphill road, and downhill. In addition, this study has shown that it could acquire information of vehicle's rotational direction(yaw) and of moving direction by using the accelerometer and geomagnetic sensor. On the basis of it this study could find the escape of route fast during moving vehicle. When it uses various MEMS sensors, it can be more intelligent and effective navigation than the system using existing GPS only. Accordingly, this study was to suggest methods of sensing, data acquisition, data processing, and simulation for sensors.

은 나노입자 프린팅 기반의 재활치료용 신축성 관절센서 개발

( Woen-sik Chae ),( Jae-hu Jung ) 한국운동역학회 2021 한국운동역학회지 Vol.31 No.3

Objective: The purpose of this study was to develop a stretchable joint motion sensor that is based on silver nano-particle. Through this sensor, it can be utilized as an equipment for rehabilitation and analyze joint movement. Method: In this study, precursor solution was created, after that, nozel printer (Musashi, Image master 350PC) was used to print on a circuit board. Sourcemeter (Keithley, Keithley-2450) was used in order to evaluate changes of electric resistance as the sensor stretches. In addition, the sensor was attached on center of a knee joint to 2 male adults, and performed knee flexion-extension in order to evaluate accurate analysis; 3 infrared cameras (100 Hz, Motion Master 100, Visol Inc., Korea) were also used to analyze three dimensional movement. Descriptive statistics were suggested for comparing each accuracy of measurement variables of joint motions with the sensor and 3D motions. Results: The change of electric resistance of the sensor indicated multiple of 30 times from initial value in 50% of elongation and the value of electric resistance were distinctively classified by following 10%, 20%, 30%, 40% of elongation respectively. Through using the sensor and 3D camera to analyze movement variable, it showed a resistance of 99% in a knee joint extension, whereas, it indicated about 80% in flexion phase. Conclusion: In this research, the stretchable joint motion sensor was created based on silver nanoparticle that has high conductivity. If the sensor stretches, the distance between nanoparticles recede which lead gradual disconnection of an electric circuit and to have increment of electric resistance. Through evaluating angle of knee joints with observation of sensor's electric resistance, it showed similar a result and propensity from 3D motion analysis. However, unstable electric resistance of the stretchable sensor was observed when it stretches to maximum length, or went through numerous joint movements. Therefore, the sensor need complement that requires stability when it comes to measuring motions in any condition.

Estimation of Angular Acceleration By a Monocular Vision Sensor

임준후,김희성,이제영,최광호,강성진,천세범,이형근 사단법인 항법시스템학회 2014 Journal of Positioning, Navigation, and Timing Vol.3 No.1

Recently, monitoring of two-body ground vehicles carrying extremely hazardous materials has been considered as one of the most important national issues. This issue induces large cost in terms of national economy and social benefit. To monitor and counteract accidents promptly, an efficient methodology is required. For accident monitoring, GPS can be utilized in most cases. However, it is widely known that GPS cannot provide sufficient continuity in urban cannons and tunnels. To complement the weakness of GPS, this paper proposes an accident monitoring method based on a monocular vision sensor. The proposed method estimates angular acceleration from a sequence of image frames captured by a monocular vision sensor. The possibility of using angular acceleration is investigated to determine the occurrence of accidents such as jackknifing and rollover. By an experiment based on actual measurements, the feasibility of the proposed method is evaluated.

Estimation of Angular Acceleration By a Monocular Vision Sensor

Lim, Joonhoo,Kim, Hee Sung,Lee, Je Young,Choi, Kwang Ho,Kang, Sung Jin,Chun, Sebum,Lee, Hyung Keun The Institute of Positioning 2014 Journal of Positioning, Navigation, and Timing Vol.3 No.1

Recently, monitoring of two-body ground vehicles carrying extremely hazardous materials has been considered as one of the most important national issues. This issue induces large cost in terms of national economy and social benefit. To monitor and counteract accidents promptly, an efficient methodology is required. For accident monitoring, GPS can be utilized in most cases. However, it is widely known that GPS cannot provide sufficient continuity in urban cannons and tunnels. To complement the weakness of GPS, this paper proposes an accident monitoring method based on a monocular vision sensor. The proposed method estimates angular acceleration from a sequence of image frames captured by a monocular vision sensor. The possibility of using angular acceleration is investigated to determine the occurrence of accidents such as jackknifing and rollover. By an experiment based on actual measurements, the feasibility of the proposed method is evaluated.

블레이드 각속도 통계 정보 기반 풍력 발전기 고장 진단 모니터링 시스템

김병진,강석주,박준영,Kim, Byoungjin,Kang, Suk-Ju,Park, Joon-Young 한국전력공사 2016 KEPCO Journal on electric power and energy Vol.2 No.4

본 논문에서는 풍력 발전 시스템에서 발생 가능한 고장 중 블레이드에 대한 고장 진단 방법으로 자이로 센서를 이용한 각속도 측정을 통해 고장 진단용 모니터링 시스템을 제안한다. 제안하는 방법은 우선 손상이 발생하지 않은 상태의 블레이드 회전에 대한 각속도 dataset을 구성한다. 블레이드 상태 판별을 위한 dataset 구성이 되었다면, 임의의 상태에 대한 블레이드가 부착된 풍력 발전기를 일정한 힘을 가해 회전시킨 후 최종적으로 블레이드의 손상 정도에 따라 발생하는 각속도의 차이를 비교하여 블레이드의 고장 진단에 대해 판단한다. 실험 결과 정상 상태의 블레이드는 초당 1회 (초당 $360^{\circ}$) 이상의 속도로 회전을 진행하며, 손상 상태의 블레이드는 초당 1회 미만의 속도로 회전하며 표준 편차가 급격히 증가하는 것을 확인할 수 있었다. In this paper, we propose a new fault diagnosis monitoring system using gyro sensor-based angular velocity calculation for blades of the wind turbine system. First, the proposed system generates the angular velocity dataset for the rotation speed of the normal blade. Using the dataset, we estimate and evaluate the state of blades for the wind turbine by comparing the current state with the pre-calculated normal state. In the experimental results, the angular velocity of the normal state was higher than $360^{\circ}/s$ while that of the damaged blades was lower than $360^{\circ}/s$ and the standard deviation of the angular velocity was significantly increased.

회전각 검출용 3축 수직 Hall 센서

이지연,남태철,Lee, Ji-Yeon,Nam, Tae-Chul 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.9

A three branches vortical Hall sensor for detecting rotation angle of brushless motor has fabricated. The sensor is constructed three branches of $150{\mu}m$ width and $300{\mu}m$ distance from central electrode to Hall electrode. Each branch has one Hall output and one Hall input. The central electrode acts as common driving input. According to rotation angle change of brushless motor, sensor gives three position signals phase shifted by $120^{\circ}$. The sensitivity of sensor is 200V/A$\cdot$T at magnetic field of 0.1 T and constant driving current of 1mA. It has also showed three sine waves of Hall output voltages with $120^{\circ}$ phase over one motor rotation. The noise can limit sensor's resolution. We have measured sensor's noise characteristics. The detectable minimum magnetic field is $20{\mu}T$ at driving current 1mA, measured frequency 1 kHz and bandwidth$({\Delta}f)$ of 1Hz.

Fall detection using smart phone and ubiquitous pulse wave sensor

Wan Azizul,Shinnosuke Imai,Tadahiro Hasegawa 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

We have proposed the fall detection method using acceleration and angular velocity sensor in android device as well as pulse wave sensor in other device. Acceleration and angular velocity are measured by smartphone’s sensors while pulse wave is measured by an external sensor. The application software for detecting the start to fall using smartphone, and the ubiquitous pulse wave sensor that can measure a human pulse even during fall motion was developed successfully.

실차 적용을 통한 각속도센서 특성 연구

金炳禹(Byeong-Woo Kim) 대한전기학회 2007 전기학회논문지 Vol.56 No.7

A surface micro machined angular rate sensor utilizing a vibrating MEMS structure on a silicon has been developed. These tuning fork angular rate sensor,s are extremely rugged, inherently balanced, and easy to fabricate. The device is fabricated using a temperature compensation method based on automatic gain control technique. A linearity of approximately 0.6%, limited by the on-chip electronics has been obtained with this new sensor. Tests of the sensor demonstrate that its performance is equivalent to that required for implementation of a yaw control system. Vehicle handling and safety are substantially improved using the sensor to implement yaw control.

광섬유 종단각도 효과를 이용한 관절각 측정

정구인(Gu-In Jung),김지선(Ji-Sun Kim),이태희(Tae-Hee Lee),최주현(Ju-Hyeon Choi),오한별,김아희(A-Hee Kim),전재훈(Jae-Hoon Jun) 대한전기학회 2014 전기학회논문지 Vol.63 No.7

The measurement of joint angle is important to evaluate the patient’s disability. The modified fiber tip and light propagation of the developed fiber sensor were investigated to increase the range of angle detection. Different shapes of fiber tips were manufactured with a polishing machine to deliver light signal in various patterns. Output signals were analyzed to obtain joint angle change with inverse polynomial models. The measured joint angles were displayed with LabVIEW program and the reliability was tested by comparing with a commercial angle sensor. This method can be used in rehabilitation field to determine patient’s progress.