• Title/Summary/Keyword: Angular Filter

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Transfer alignment for strapdown inertial navigation system by angle matching method (스트랩다운 관성항법장치의 각을 이용한 초기전달 정렬기법)

  • 송기원;전창배;김현백
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.29-33
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    • 1993
  • This paper suggests Kalman filter formulation using by precision GINS output angle for SDINS initial transfer alignment of missile. The Kalman filter model was derived from quaternion parameters and the transfer alignment system by angle matching method satisfies azimuth observability in horizontal angular motion. The estimated error of SDINS attitude settles to less 3mrad(1.sigma.) in 200 seconds at proper sea state.

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Localization using Fuzzy-Extended Kalman Filter (퍼지-확장칼만필터를 이용한 위치추정)

  • Park, Sung-Yong;Park, Jong-Hun;Wang, Hai-Yun;No, Jin-Hong;Huh, Uk-Youl
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.2
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    • pp.277-283
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    • 2014
  • This paper proposes robot localization using Fuzzy-Extended Kalman Filter algorithm of the mobile robots equipped with least sensors. In order to improve the accuracy of the localization, we usually add the sensors or equipment. However, it increases the simulation time and expenses. This paper solves this problem using only the odometer and ultrasonic sensors to get the localization with the Fuzzy-Extended Kalman Filter algorithm method. By inputting the robot's angular velocity, sensor data variation, and residual errors into the fuzzy algorithm, we get the sensor weight factor to decide the sensor's importance. The performance of the designed method shows by the simulation and Pioneer 3-DX mobile robot test in the indoor environment.

A digital filter design applied to the manual tracking system to predict future position (차량의 미래위치 추정을 위한 수동추적 시스템의 디지털 필터 설계)

  • 박용운;강윤식;김상원
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1332-1335
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    • 1996
  • It is very important to predict the future position for the heavy vehicle with evasive maneuvering. In this paper, we considered for the manual image tracking system. The vehicle images are received from gyro stabilized mirror system, pass through the optical lens, processed, and displayed on the TV monitor. The operator try to lay the reticle to the center of vehicle image. When the vehicle is moving, the mirror platform (actually the line of sight) should follow the vehicle and the angular rate information is picked up from the mirror stabilized system. This rate signal should be used to predict the future vehicle position. The problem is that the visual system of the human operator is in the closed loop system. The rate signals are disturbed by the operator. In addition, there are some non linearities concerned with the control handle bar and the servo control system. The proposed Kalman filter, combined with some modifications for operator disturbance rejection, improved the predication of the future vehicle position when compared with the conventional passive filter used.

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Analysis of Transmission Spectrum Characteristics of Second-Order Fiber Flexible Comb Filter Based on Polarization-Diversity Loop (편광상이 고리 기반 2차 광섬유 유연 빗살 필터의 투과 스펙트럼 특성 분석)

  • Park, Kyoungsoo;Lee, Yong Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.12
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    • pp.1-7
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    • 2015
  • In this paper, we propose a second-order fiber flexible comb filter based on a polarization-diversity loop(PDL). The proposed filter consists of a polarization beam splitter, four half-wave plates(HWPs), and three high birefringence fiber(HBF) segments. In the previous Solc-type second-order filter based on the PDL, HBF segments were fusion-spliced with a fixed angle offset between their principal axes with each other. But, the proposed filter implemented by inserting two HWPs between three HBF segments has a great flexibility in adjusting relative angular difference between the principal axes of two adjacent HBF segments. Owing to this flexibility, second-order transmission spectra, which had a channel spacing of ~0.8nm, could be interleaved by controlling the orientation angles of four HWPs. The output transmission spectra of the proposed filter were theoretically analyzed and experimentally verified.

A Study on the Visual Odometer using Ground Feature Point (지면 특징점을 이용한 영상 주행기록계에 관한 연구)

  • Lee, Yoon-Sub;Noh, Gyung-Gon;Kim, Jin-Geol
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.3
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    • pp.330-338
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    • 2011
  • Odometry is the critical factor to estimate the location of the robot. In the mobile robot with wheels, odometry can be performed using the information from the encoder. However, the information of location in the encoder is inaccurate because of the errors caused by the wheel's alignment or slip. In general, visual odometer has been used to compensate for the kinetic errors of robot. In case of using the visual odometry under some robot system, the kinetic analysis is required for compensation of errors, which means that the conventional visual odometry cannot be easily applied to the implementation of the other type of the robot system. In this paper, the novel visual odometry, which employs only the single camera toward the ground, is proposed. The camera is mounted at the center of the bottom of the mobile robot. Feature points of the ground image are extracted by using median filter and color contrast filter. In addition, the linear and angular vectors of the mobile robot are calculated with feature points matching, and the visual odometry is performed by using these linear and angular vectors. The proposed odometry is verified through the experimental results of driving tests using the encoder and the new visual odometry.

Spectral Characteristics of Multiwavelength-Switchable First-Order Fiber Flexible Filter based on Polarization-Diversity Loop (편광상이 고리 형태의 다파장 스위칭 가능한 1차 광섬유 유연 필터의 스펙트럼 특성)

  • Park, Kyoungsoo;Kim, Youngho;Lee, Yong Wook
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.8
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    • pp.6-13
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    • 2014
  • In this paper, a multiwavelength-switchable first-order fiber flexible filter is newly proposed, which is based on a polarization-diversity loop. The proposed filter consists of a polarization beam splitter, three half-wave plates(HWPs), and two high birefringent fibers(HBFs). The proposed filter has a good flexibility in adjusting relative angular difference between the principal axes of two HBFs by inserting an HWP between two HBFs. The first-order flat-top or narrow band transmission spectra and the zeroth-order transmission spectra, which had a channel spacing of ~0.8nm, could be obtained by controlling the three HWPs, and, in particular, each of them could also be interleaved. In addition, zeroth-order transmission spectra with a channel spacing of ~0.8nm could be flexibly converted into those with a channel spacing of ~0.4nm through the control of three HWPs, and also be interleaved. The transmission characteristics of the proposed filter was theoretically analyzed and experimentally verified.

Trajectory Estimation of a Moving Object using Kohonen Networks

  • Ju, Jin-Hwa;Lee, Dong-Hui;Lee, Jae-Ho;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.2033-2036
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    • 2004
  • A novel approach to estimate the real time moving trajectory of an object is proposed in this paper. The object position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Kalman filter and neural networks are utilized. Since the Kalman filter needs to approximate a non-linear system into a linear model to estimate the states, there always exist errors as well as uncertainties again. To resolve this problem, the neural networks are adopted in this approach, which have high adaptability with the memory of the input-output relationship. Kohonen Network(Self-Organized Map) is selected to learn the motion trajectory since it is spatially oriented. The superiority of the proposed algorithm is demonstrated through the real experiments.

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Implementation of a Hybrid Navigation System for a Mobile Robot by Using INS/GPS and Indirect Feedback Kalman Filter (INS/GPS와 간접 되먹임 칼만 필터를 사용하는 이동 로봇의 복합 항법 시스템의 구현)

  • Kim, Min J.;Joo, Moon G.
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.6
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    • pp.373-379
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    • 2015
  • A hybrid navigation system is implemented to apply for a mobile robot. The hybrid navigation system consists of an inertial navigation system and a global positioning system. The inertial navigation system quickly calculates the position and the attitude of the robot by integrating directional accelerations, angular speed, and heading angle from a strap-down inertial measurement unit, but the results are available for a short time since it tends to diverge quickly. Global positioning system delivers position, heading angle, and traveling speed stably, but it has large deviation with slow update. Therefore, a hybrid navigation system uses the result from an inertial navigation system and corrects the result with the help of the global positioning system where an indirect feedback Kalman filter is used. We implement and confirm the performance of the hybrid navigation system through driving a car attaching it.

A Test Technique for Performance Evaluation of a Filter and Control Loop on the Missile Vibration using Floating System (부유시스템을 이용한 유도탄 조종루프 진동저감 성능확인 시험기법)

  • Kim, KyungHwan;Park, BumSoo;Lee, Hyun;Kim, SangJae;Chung, JaeWook
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.5
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    • pp.623-629
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    • 2018
  • The acceleration and the angular velocity that include natural frequencies of a missile detected by Inertial Measurement Unit(IMU) are transmitted to the control loop of a missile. The control loop command that is calculated using above signals can cause the resonance of the missile while it flies. Hence it is common to adapt the filter and the control loop for attenuating or eliminating the undesired signals such as natural frequencies. This paper introduces the new test technique using a floating system for performance evaluation of the designed filter and the control loop prior to a flight test. The proposed scheme can check out the degradation property of vibration in the filter and the control loop, while the conventional hardware-in-the-loop simulation(HILS) scheme cannot.

Evaluation on Drainage Capacity of Cylindrical Drain with Different Core Shapes (코아형식에 따른 원통형 배수재의 구멍막힘에 의한 배수능력 평가비교)

  • Lee Kwang-Yeol;Nugroho David Setiawan;Yun Sung-Tae;Ji Ho-Yeol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.311-315
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    • 2006
  • Various core shapes of cylindrical drains are used for accelerating primary consolidation for soft clay deposits, but serious harmful disadvantages on drainage capacity may occur on cylindrical drains due to confining Pressure when they are installed in that soil. In this study, two different core shapes of cylindrical drain are used to evaluate the drainage capacity with consideration of clogging effects on their filter jackets for an applied confining pressure. Column tests with radial drainage system were conducted under confining pressure of 50 kPa for 13 days. Two parameters which are discharge and accumulated volume of water drained were measured as the time elapsing. From this experimental study, the results showed that at the Initial stage before the clogging developed enough, the cylindrical drain with angular-type-plastic-core could produce discharge twice higher (maximum) than those with round-type. After 13 days had passed on, cylindrical drain with angular-type-plastic-core could produce discharge only 20% higher than those with round-type one. Eventually, there is a possibility that the efficiency of using angular-type-cylindrical-drain will be similar to the round-type one as the clogging develops more.

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