• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.270-270
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• 2019

관성측정장치(Inertial Measurement Unit)는 선박, 잠수함, 항공기 등 여러 응용분야에서 적용되어 자세 측정 영역에 주로 사용되고 있지만, 이런 장비는 고가의 장비이기 때문에 특수 분야에서만 한정적으로 이용되어 왔다. 본 연구에서는 저가의 관성측정장치(Inertial Measurement Unit)를 이용하여 실시간으로 선박의 속도와 방향, 중력, 가속도를 측정함으로써 선박의 감항성을 확인하며, 더 나아가 실선 선박의 저항 및 조종성능 추정을 위한 유체력 미계수 추정을 위한 연구방법을 고안하였다. 이에 본 연구는 실제 해상에서 선체 운동요소를 계측하고, 계측된 데이터의 처리 및 해석을 통하여 선박의 종합적인 안전성 평가 및 실선의 저항 및 조종성능 추정을 행하였다.

• 한국항해항만학회지
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• 제35권10호
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• pp.785-791
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• 2011

본 논문에서는 소형 선박용 관성측정장치(Inertial Measurement Unit, IMU) 개발에 적합한 MEMS(Micro-Electro Mechanical System) 기반의 관성 센서 평가와 선정에 관하여 기술했다. 먼저, 오일러 공식에 기초한 관성 센서의 오차 모델과 잡음 모델을 정의하고, 앨런 분산(Allan Variance) 기법과 몬테카르로(Monte Carlo) 시뮬레이션 기법을 도입하여 관성 센서를 평가하였다. ADIS16405, SAR10Z, SAR100Grade100, LIS344ALH, ADXL103 등 다섯 가지 관성 센서에 대한 평가결과, ADIS16405의 자이로와 가속도계를 조합한 경우 오차가 가장 작게 나타났는데, 600 초 경과시 속도 오차의 표준편차가 약 160 m/s, 위치 오차의 표준편차가 약 35 km로 나타났다. 평가를 통해 ADIS16405 관성 센서가 IMU 구축에 최적임을 알았고, 이러한 오차 감소 방법에 대해서 참고문헌을 조사하여 검토하였다.

• 제어로봇시스템학회논문지
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• 제16권12호
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• pp.1167-1175
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• 2010

This paper presents the use of the inertial measurement unit information and the infrared sector information for getting the position of an object. Travel distance is usually calculated from the double integration of the accelerometer output with respect to time; however, the accumulated errors due to the drift are inevitable. The orientation change of the accelerometer also causes error because the gravity is added to the measured acceleration. Unless three axis orientations are completely identified, the accelerometer alone does not provide correct acceleration for estimating the travel distance. We propose a way of minimizing the error due to the change of the orientation. In order to reduce the accumulated error, the infrared sector information is fused with the inertial measurement unit information. Infrared sector information has highly deterministic characteristics, different from RFID. By putting several infrared emitters on the ceiling, the floor is divided into many different sectors and each sector is set to have a unique identification. Infrared light based sector information tells the sector the object is in, but the size of the uncertainty is too large if only the sector information is used. This paper presents an algorithm which combines both the inertial measurement unit information and the sector information so that the size of the uncertainty becomes smaller. It also introduces a framework which can be used with other types of the artificial landmarks. The characteristics of the developed infrared light based sector and the proposed algorithm are verified from the experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.2945-2965
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• 2023

The laser inertial measurement unit is a precision device widely used in rocket navigation system and other equipment, and its quality is directly related to navigation accuracy. In the quality evaluation of laser inertial measurement unit, there is inevitably uncertainty in the index input information. First, the input numerical information is in interval form. Second, the index input grade and the quality evaluation result grade are given according to different national standards. So, it is a key step to transform the interval information input by the index into the data form consistent with the evaluation result grade. In the case of uncertain input, this paper puts forward a method based on probability distribution to solve the problem of asymmetry between the reference grade given by the index and the evaluation result grade when evaluating the quality of laser inertial measurement unit. By mapping the numerical relationship between the designated reference level and the evaluation reference level of the index information under different distributions, the index evidence symmetrical with the evaluation reference level is given. After the uncertain input information is transformed into evidence of interval degree distribution by this method, the information fusion of interval degree distribution evidence is carried out by interval evidential reasoning algorithm, and the evaluation result is obtained by projection covariance matrix adaptive evolution strategy optimization. Taking a five-meter redundant laser inertial measurement unit as an example, the applicability and effectiveness of this method are verified.

• 한국해양공학회지
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• 제11권1호
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• pp.95-105
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• 1997

This paper presents a Inertial Measuring Unit(IMU) for motion measurement of an AUV. The IMU is composed of three parts: inertial sensors with three servo accelerometers and three rate gyros, an analog/digital interface board, and a signal processing board with TMS320C31 DSP processor. The IMU is a class of strap-down inwetial navigation system does not applicable directly to the navigation system in consequence of the AUV and integrated sensors for an integrated navigation system of the AUV. Fast calculstion of direction cosine matrix for the coordinate transformation body to reference is obtained through the DSP processor. A switching algotrithm is used to lessen the low frequency drift effect of the gyros in the vertical plane with use of low pass filtering of the signal of the accelerometers.

• 한국해양공학회지
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• 제17권6호
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• pp.83-90
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• 2003

This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), and a Doppler velocity log (DVL), accompanied by a magnetic compass. The errors of inertial measurement units increase with time, due to the bias errors of gyros and accelerometers. A navigational system model is derived, to include the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 20. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors, and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o,f equations of motion of SAUV, using a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance, by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass, and a depth sensor. The error of the estimated position still slowly drifts in the horizontal plane, about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.

• 한국해양공학회지
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• 제19권5호
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• pp.71-77
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• 2005

This paper presents an integrated underwater navigational algorithm for unmanned underwater vehicles, using additional two-range transducers. This paper proposes a measurement model, using two range measurements, to improve the performance of an IMU-DVL (inertial measurement unit - Doppler velocity log) navigation system for long-time operation of underwater vehicles, excluding DVL measurement. Extended Kalman filter was adopted to propagate the error covariance, to update the measurement errors, and to correct the state equation when the external measurements are available. Simulation was conducted with the 6-d.o.f nonlinear numerical model of an AUV in lawn-mowing survey mode, at current flaw, where the velocity information is unavailable. Simulations illustrate the effectiveness of the integrated navigation system, assisted by the additional range measurements without DVL sensing.

• International Journal of Aeronautical and Space Sciences
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• 제11권3호
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• pp.234-239
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• 2010

The utilization of micro-electro-mechanical system (MEMS) gyros and accelerometers in low-level inertial measurement unit (IMU) influences cost effectiveness in a positive way under the condition that device error characteristics are fully calibrated. The conventional calibration process utilizes a rate table; however, this paper proposes a new method for achieving reference calibration data from the natural motion of pendulum to which the IMU undergoing calibration is attached. This concept was validated with experimental data. The pendulum angle measurements correlate extremely well with the solutions acquired from the pendulum equation of motion. The calibration data were computed using the regression method. The whole process was validated by comparing the measurement from the 6 sensor components with the measurements reconstructed using the identified calibration data.

• 실천공학교육논문지
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• 제10권2호
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• pp.119-124
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• 2018

IMU(Inertial Measurement Unit) 센서의 가속도와 각속도를 이용하여 거리측정을 하고 측정값을 이용하여 사용자가 원하는 실내공간에 적용하여 사용자 혹은 디바이스가 실내공간을 인식하는 교육용 장비를 소개한다. 본 교육장비를 이용해서 다양한 위치 인식 및 추적 알고리즘을 학습할 수 있고 창의적 공학설계 작품을 구현할 수 있다. IMU 센서의 데이터 값을 $I^2C$(Inter-Integrated Circuit)을 통해 MCU(microcontroller unit)에 전송하고 필터와 연산방식을 통해 데이터 값을 처리 후 실내 위치 인식 알고리즘을 통해 위치인식을 한다. 그리고 무선통신을 이용하여 처리된 값을 송수신하여 사용자가 인식하도록 설계한다. 본 교육 장비를 이용하여 "IMU센서를 이용하여 이동거리를 산출과 데이터 값을 이용한 가상공간 구현 및 인식"의 사례를 소개하고 그 설계를 기반하여 다양한 창의적 공학설계 적용에 대해서 논한다.

• 항공우주기술
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• 제9권1호
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• pp.50-59
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• 2010

본 논문에서는 KSLV-I 관성항법유도장치 관성계측부에 대한 오차 모델 확인 및 항법오차 추정을 위해 관성항법유도장치 탑재 소프트웨어를 통한 정렬 및 항법계산 결과와 관성계측유닛 후처리 소프트웨어인 Inertial Explorer를 통한 정렬 및 항법계산 결과를 비교하였다. Inertial Explorer의 칼만필터를 통한 관성계측부 오차 추정 정확도 확인을 위해 Allan Variance를 통한 관성계측부 확률적 오차모델을 이용하여 관성계측부 오차모델 상태변수 공분산 값을 설정하였고, 정적상태에서의 정렬 및 항법시험, 동적환경에서의 주행항법시험을 수행하였다. INGU 탑재 소프트웨어와 Inertial Explorer를 통한 정렬 및 항법계산 결과 비교를 통해 본 논문에 설정한 KSLV-I 관성항법유도장치 관성센서 오차모델의 유효성을 확인하였다.