• 한국지능시스템학회논문지
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• 제21권4호
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• pp.518-524
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• 2011

본 논문은 퍼지 추론 시스템(FIS: fuzzy inference system)을 이용하여 자이로스코프를 사용하지 않는 관성 항법 장치(GFINS: gyroscope free inertial navigation system)의 가속도계 데이터를 보정하는 방법에 관한 연구이다. 일반적인 관성항법 장치(INS: inertial navigation system)는 주로 가속도계와 같은 병진운동을 감지하는 관성 센서와 자이로스코프와 같은 회전 운동을 감지하는 관성 센서를 이용하여 위치와 yaw각을 측정하는 장치이다. 하지만 INS는 자이로스코프를 사용하기 때문에 소형화 및 저전력 설계가 어렵다. 이러한 문제를 해결하기 위하여 자이로스코프를 사용하지 않는 GFINS에 대한 연구가 활발히 진행되고 있다. GFINS에 사용되는 가속도계는 적분과 외란에 의한 오차가 시간이 지남에 따라 누적되는 문제가 있다. 따라서 본 논문에서는 가속도계의 누적 오차 문제를 해결하기 위해, 레이저 내비게이션과 가속도계의 선속도 비율과 엔코더와 가속도계의 선속도 비율을 통해 GFINS의 데이터를 보정하는 FIS를 제안한다. 제안된 Fuzzy-GFINS를 평가하기 위해, 직접 제작한 메카넘 휠 AGV(autonomous ground vehicle)에 제안된 GFINS를 적용하였다. 실험 결과, 제안된 방법이 GFINS의 출력 데이터를 효과적으로 보정하는 것을 확인 할 수 있었다.

• Journal of Positioning, Navigation, and Timing
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• 제13권3호
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• pp.237-244
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• 2024

An Attitude and Heading Reference System (AHRS) provides the attitude of a vehicle with a constant velocity using an Inertial Measurement Unit (IMU) and a magnetometer. In this case, in order to avoid the disadvantage of a gyroscope, an AHRS using a Gyro-Free IMU (GF-IMU) that is composed of only accelerometers may be considered instead of the gyroscopes. In this paper, a design method of an AHRS using a GF-IMU is proposed. The proposed AHRS consists of roll and pitch calculation, yaw calculation, angular acceleration and angular velocity calculation, attitude calculation, and a Kalman filter. In particular, since the angular velocity cannot be measured from a gyroscope, the angular acceleration is obtained from the accelerometer output, and the angular velocity is calculated by integrating it. In order to show the usefulness of the proposed method, a performance evaluation was carried out. The performance evaluation results show that the attitude estimation performance of the proposed AHRS is similar to that of the conventional AHRS.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.291-294
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• 2004

There are many position fixing systems in the world from ancient times. But the principles are to compare the position to want to know with the known position already. The position finding system which is not restricted by weather condition and/or electronic apparatus has been sought. The best system is the GPS as far. But the system has the fatal faults as follows; 1. to depend on satellite's accuracy, 2. not to use underwater. This paper is to investigate theoretically position fixing and north finding by using free gyroscope. This paper introduce a position fixing and north finding method by measuring inclination of 2 free gyroscopes. And this system does not depend on the weather condition and underwater condition. What is more, it could use on the planets, if the gravity exits.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.53-56
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• 1987

Gyroscope is a key sensor for inertial navigation system (INS) which is a navigational instrument necessary to guide and control a free vehicle, and an important instrument for defense, aeronautical, and space industries that is and will be actively involved. In this study, design parameters, scale factor and linearity, of torquer which is one of the components of two degree of freedom dynamically tuned gyroscope (DTG) are presented. The magnetic circuit of torquer is so complicated that it is difficult to analyze it with analytic method. Thus these parameters are calculated by using finite element method with analysis of magnetic vector potential for axisymmetric 3-dimension magnetic field.

• 한국정밀공학회지
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• 제14권2호
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• pp.13-22
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• 1997

Strapdown inertial navigation system(SDINS) is a navigational instruments necessary to guide and con- trol a free vehicle. In this study, an error analysis of mechanical parts is carried out for manufacturing a dynamically tuned gyroscope. The errors usually come from the tolerance in machining and assembly. In the error analysis, a criterion to be considered during designing and manufacturing is proposed by quanti- tatively analyzing the effect of DTG performance by tolerances. The theory of dynamic balancing is deduced and unbalance is reduced through experiment.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.117-120
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• 2004

이 논문은 프리 자이로스코프의 방향의존성을 이용하여 위치를 결정하는 방댑을 이론적으로 검토한 것이다. 임의 기준 위치 혹은 출발 위치에 대하여 두 개 이상의 프리 자이로스코프의 자이로축의 경사각을 측정하고 아울러 기준 위치에서 시작한 시간의 경과를 측정한 다음, 이 두 가지의 기본 요소를 이용하여 위치를 구하는 것이다.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.615-623
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• 2006

The gyroscope free strap-down INS is composed only of accelerometers. Any gyroscope free INS navigation error is deeply affected by the accuracy of the sensor bias, scale factor, orientation and location error. However these parameters can be found by calibration. There is an important research issue about a multi-position calibration method in this paper. It provides a novel method to find the error parameters for the six-accelerometer INS. A superior simulation is shown that the multi-position calibration can find the specifications of a six-accelerometer INS in laboratory. From these parameters the six-accelerometer INS could apply in realistic navigation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.327-328
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• 2007

This paper is to develop the path-tracking of free-ranging AGV(Autonomous Guided Vehicle). Encorders are used to trace the location of the AGV. A gyroscope is used to complement encorders that have the error accumulation problem by increasing the distance covered. A sensor fusion technique is applied to correct the error. The path of the AGV is controlled by kinematics and PID which is obtained the data from the sensor fusion. Experimental results are presented to verify the efficiency of proposed method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.930-937
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• 1994

Straodown intertial navigation system(SDINS) is a navigational instrument necessary to guide and control a free vehicle. Dynamically Tuned Gyroscope(DTG) which is widely applied to SDINS convers a wide dynamic range and is simple and small. In study, the analysis of mechanical parts or sensor parts and research of balancing is performed for manufacturing a DTG. In error analysis the criterion considered during designing and manufacturing is established by quantitatively anayzing the effect of DTG performance by tolerance. And the theory of dynamic balancing is derived and unbalance is reduced through experiment. And the stiffness of flexure is verified by tuning experiment.

• 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.