• 제목/요약/키워드: Error Ellipsoid

검색결과 22건 처리시간 0.026초

타원체를 이용한 3축 센서의 실시간 보정 알고리듬 개발 (Development of the Calibration Algorithm of 3 Axis Vector Sensor Using Ellipsoid)

  • 황정문;김정한
    • 한국정밀공학회지
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    • 제32권7호
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    • pp.643-651
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    • 2015
  • Multi-axis magnetic and accelerometer sensor are widely used in consumer product such as smart phones. The vector output of multi-axis sensors have errors on each axis such as offset error, scale error, non-orthogonality. These errors cause many problems on the performance of the applications. In this paper, we designed the effective inline compensation algorithm for calibrating of 3 axis sensors using ellipsoid for mass production of multi-axis sensors. The outputs with those kinds of errors can be modeled by ellipsoid, and the proposed algorithm makes sequential mappings of the virtual ellipsoid to perfect sphere which is calibrated function of the sensor on three-dimensional space. The proposed calibrating process composed of four main stages and is very straightforward and effective. In addition, another imperfection of the sensor such as the drift from temperature can be easily inserted in each mapping stage. Numerical simulation and experimental results shows great performance of the proposed compensation algorithm.

Human Gender and Motion Analysis with Ellipsoid and Logistic Regression Method

  • Ansari, Md Israfil;Shim, Jaechang
    • Journal of Multimedia Information System
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    • 제3권2호
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    • pp.9-12
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    • 2016
  • This paper is concerned with the effective and efficient identification of the gender and motion of humans. Tracking this nonverbal behavior is useful for providing clues about the interaction of different types of people and their exact motion. This system can also be useful for security in different places or for monitoring patients in hospital and many more applications. Here we describe a novel method of determining identity using machine learning with Microsoft Kinect. This method minimizes the fitting or overlapping error between an ellipsoid based skeleton.

A Study on the Errors In the Free-Gyro Positioning System (I)

  • Jeong Tae-Gweon
    • 한국항해항만학회지
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    • 제29권7호
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    • pp.611-614
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    • 2005
  • This paper is to develop the position error equation of in the free-gyro positioning system by using two free gyros. First, the determination of a position is analyzed on the ellipsoid of the Earth and the type of the errors is defined Finally the position error equation is introduced and developed, based on the definition of the type of errors which may be involved in the FPS.

TOA기법과 TDOA기법의 위치 오차 특성 및 DOP 비교 (Comparisons of Position Error Characteristics and DOP Between TOA and TDOA Technique)

  • 신동호;성태경
    • 제어로봇시스템학회논문지
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    • 제6권10호
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    • pp.923-927
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    • 2000
  • This paper presents a relationship between DOP for TOA and TDOA is defined using the error covariance matrix of TDOA. It is analytically shown that the error ellipsoid of TOA is as same as that of TDOA in magnitude and in orientation, which means that DOP for TOA is identical to the DOP for TDOA. By computer simulation, the positioning performance of two methods is compared, and we verify our assertion.

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이동로봇 속도 추정 성능 향상을 위한 광 마우스의 최적 배열 (Optimal Optical Mouse Array for High Performance Mobile Robot Velocity Estimation)

  • 김성복;김현빈
    • 제어로봇시스템학회논문지
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    • 제19권6호
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    • pp.555-562
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    • 2013
  • This paper presents the optimal array of optical mice for the accurate velocity estimation of a mobile robot. It is assumed that there can be some restriction on the installation of two or more optical mice at the bottom of a mobile robot. First, the velocity kinematics of a mobile robot with an array of optical mice is derived, which maps the velocity of a mobile robot to the velocities of optical mice. Second, taking into account the consistency in physical units, the uncertainty ellipsoid is obtained to represent the error characteristics of the mobile robot velocity estimation owing to noisy optical mouse measurements. Third, a simple but effective performance index is defined as the inverse of the volume of the uncertainty ellipsoid, which can be used for the optimization of the optimal optical mouse placement. Fourth, simulation results for the optimal placement of three optical mice within a given elliptical region are given.

타원체상에서 경계획선을 위한 중간점계산의 정확도 (Accuracy of Mid Point Computation for Boundary Delimitation on Ellipsoid)

  • 김병국;이종기;김정기
    • 한국측량학회지
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    • 제19권4호
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    • pp.365-372
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    • 2001
  • 나라사이의 경계를 결정하기 위한 일반적인 방법은 등거리원칙이다. 등거리원칙은 각각의 기준선 또는 기준점의 경계에서 일정한 거리까지를 경계로 정하는 방법이다. 본 연구에서는 등거리 원칙을 기본으로 하는 알고리즘으로 폭넓게 사용되고 있는 Two-Point 알고리즘과 Three-Point 알고리즘을 정립한 후, 알고리즘을 적용한 결과와 오차를 확인할 수 있는 경계 획선 프로그램을 개발하였다. 이 프로그램은 인공지물이나 지형지물이 없어 경계를 결정하기 어려운 해양경계 획선시 특히 유용하게 사용될 수 있다. 그 중간점 계산결과 타원체상에서 등거리원칙에 기초한 알고리즘을 적용하면, 지도 투영에 의한 어떤 왜곡도 없이 적용할 수 있고 평면이나 구에서 적용한 것 보다 오차가 적었다. 경계 획선 프로그램 개발을 통하여 도면을 이용한 수작업에 의한 여러 오차를 제거 할 수 있고, 해양경계협상시 신속히 대처할 수 있다. 또한, 기준선의 기준점 위치에러는 계산된 중간선의 중간점으로 전파되는 것을 확인할 수 있었고 그 오차를 확인하여 적합한 기준면을 설정 할 수 있었다.

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Rate Capability of LiFePO4 Cathodes and the Shape Engineering of Their Anisotropic Crystallites

  • Alexander, Bobyl;Sang-Сheol, Nam;Jung-Hoon, Song;Alexander, Ivanishchev;Arseni, Ushakov
    • Journal of Electrochemical Science and Technology
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    • 제13권4호
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    • pp.438-452
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    • 2022
  • For cuboid and ellipsoid crystallites of LiFePO4 powders, by X-ray diffraction (XRD) and microscopic (TEM) studies, it is possible to determine the anisotropic parameters of the crystallite size distribution functions. These parameters were used to describe the cathode rate capability within the model of averaging the diffusion coefficient D over the length of the crystallite columns along the [010] direction. A LiFePO4 powder was chosen for testing the developed model, consisting of big cuboid and small ellipsoid crystallites (close to them). When analyzing the parts of big and small rate capabilities, the fitting values D = 2.1 and 0.3 nm2/s were obtained for cuboids and ellipsoids, respectively. When analyzing the results of cyclic voltammetry using the Randles-Sevcik equation and the total area of projections of electrode crystallites on their (010) plane, slightly different values were obtained, D = 0.9 ± 0.15 and 0.5 ± 0.15 nm2/s, respectively. We believe that these inconsistencies can be considered quite acceptable, since both methods of determining D have obvious sources of error. However, the developed method has a clearly lower systematic error due to the ability to actually take into account the shape and statistics of crystallites, and it is also useful for improving the accuracy of the Randles-Sevcik equation. It has also been demonstrated that the shape engineering of crystallites, among other tasks, can increase the cathode capacity by 15% by increasing their size correlation coefficients.

Prediction of Communication Outage Period between Satellite and Earth station Due to Sun Interference

  • Song, Yong-Jun;Kim, Kap-Sung;Jin, Ho;Lee, Byoung-Sun
    • Journal of Astronomy and Space Sciences
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    • 제27권1호
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    • pp.31-42
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    • 2010
  • We developed a computer program to predict solar interference period. To calculate Sun's position, we used DE406 ephemerides and Earth ellipsoid model. The Sun's position error is smaller than 10arcsec. For the verification of the calculation, we used TU media ground station on Seongsu-dong, and MBSAT geostationary communication satellite. We analysis errors, due to satellite perturbation and antenna align. The time error due to antenna align has -35 to +16 seconds at $0.1^{\circ}$, and -27 to +41 seconds at $0.25^{\circ}$. The time errors derived by satellite perturbation has 30 to 60 seconds.

Robust Stabilization of Decentralized Dynamic Surface Control for a Class of Interconnected Nonlinear Systems

  • Song, Bong-Sob
    • International Journal of Control, Automation, and Systems
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    • 제5권2호
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    • pp.138-146
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    • 2007
  • The analysis and design method for achieving robust stabilization of Decentralized Dynamic Surface Control (DDSC) is presented for a class of interconnected nonlinear systems. While a centralized design approach of DSC was developed in [1], the decentralized approach to deal with large-scale interconnected systems is proposed under the assumption that interconnected functions among subsystems are unknown but bounded. To provide a closed-loop form with provable stability properties, augmented error dynamics for N nonlinear subsystems with DDSC are derived. Then, the reachable set for errors of the closed-loop systems will be approximated numerically in the form of an ellipsoid in the framework of convex optimization. Finally, a numerical algorithm to calculate the $L_2$ gain of the augmented error dynamics is presented.

무궁화위성 2호의 동서위치유지 박스 설정에 관한 연구 (A Study on the East-West Station Keeping Box of Koreasat 2)

  • 이상철;김방엽;박봉규
    • 한국항공우주학회지
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    • 제31권9호
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    • pp.75-81
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    • 2003
  • 정지궤도 위성의 위치는 여러 외부 교란력에 의해서 끊임없이 움직이기 때문에 우주에서 한 점으로 정의할 수 없다. 따라서 정지궤도 위성의 통신방송과 같은 일반적 임무를 수행하기 위해서는 우주의 한정된 공간인 위치유지박스 내에 운용되어야 한다. 본 연구에서는 남북위치유지 오차보다 상대적으로 큰 동서 위치유지 박스를 설정하기 위해서 여러 오차들을 유도하여 정립하였다. 이를 이용하여 무궁화위성에서 사용하고 있는 7일의 위치유지주기를 검증하고 14일로 위치유지 주기를 늘릴 경우의 문제점을 분석하였다.