• 제목/요약/키워드: quaternion

검색결과 190건 처리시간 0.023초

Modified Rodrigues Parameter 기반의 인공위성 관성모멘트 추정 연구 (Spacecraft Moment of Inertial Estimation by Modified Rodrigues Parameters)

  • 방효충
    • 한국항공우주학회지
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    • 제38권3호
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    • pp.243-248
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    • 2010
  • 본 연구에서는 인공위성의 관성 모멘트 추정을 위해 MRP(Modified Rodrigues Parameter) 자세 변수기반의 추정기를 설계하였다. MRP는 인공위성 자세 결정시 쿼터니 언(Quaternion) 파라미터의 구속 조건으로부터 발생하는 필터의 오차 공분산 행렬의 특이(Singularity) 현상을 피할 수 있는 장점이 있다. 한편 MRP의 경우 자세각 변위가 클 경우에 역시 특이현상이 발생할 수 있어 이를 피하기 위해 적절한 자세각 범위에서 인위적인 기준 운동을 생성하여 필터 설계에 적용하였다. 쿼터니언 파라미터의 단점을 극복하여 보다 안정된 오차 공분산 갱신 결과의 필터의 개선된 성능을 예상할 수 있다.

Nonlinear Attitude Control for a Rigid Spacecraft by Feedback Linearization

  • Hyochoong Bang;Lee, Jung-Shin;Eun, Youn-Ju
    • Journal of Mechanical Science and Technology
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    • 제18권2호
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    • pp.203-210
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    • 2004
  • Attitude control law design for spacecraft large angle maneuvers is investigated in this paper. The feedback linearization technique is applied to the design of a nonlinear tracking control law. The output function to be tracked is the quaternion attitude parameter. The designed control law turns out to be a combination of attitude and attitude rate tracking commands. The attitude-only output function, therefore, leads to a stable closed-loop system following the given reference trajectory. The principal advantage of the proposed method is that it is relatively easy to produce reference trajectories and associated controller.

작동기 수가 부족한 위성체의 자세안정화기법 (Stabilizing Control Law of Underactuateted Spacecraft)

  • 김성필;김유단
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.102-102
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    • 2000
  • In this paper, attitude control laws are proposed for an underactuated spacecraft. The stabilization problem of the complete system including the kinematics as well as the dynamics of the spacecraft is addressed. The quaternion parameterization is used. The key idea is that the angular velocity of a uncontrolled axis is first regulated and then, the other states are regulated. Based on numerical simulations, it is conjectured that the closed-loop nonlinear system of a spacecraft with the proposed control laws is globally asymptotically stable. The control law for the stabilization problem around the origin as well as the command following problem are proposed. The numerical examples indicate that the stabilization of an underactuated asymmetric spacecraft can be achieved successfully.

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플랫폼 토크 명령에 의한 자세오차 미분방정식 유도 (Derivation of Attitude Error Differential Equations by Platform Torque Commands)

  • 김갑진;송기원
    • 제어로봇시스템학회논문지
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    • 제9권7호
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    • pp.556-562
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    • 2003
  • This paper presents new attitude error differential equations to define attitude errors as the rotation vector for inertial navigation systems. Attitude errors are defined with the rotation vector between the reference coordinate frame and the platform coordinate frame, and Platform dynamics to the reference coordinate frame due to platform torque command errors are defined. Using these concepts for attitude error definition and platform dynamics, we have derived attitude error differential equations expressed in original nonlinear form for GINS and SDINS and showed that these are equivalent to attitude error differential equations expressed in known linear form. The relation between attitude errors defined by the rotation vector and attitude errors defined by quaternion is clearly presented as well.

핸드-아이 보정과 능동 스테레오 비젼의 일반적 해석 (The General Analysis of an Active Stereo Vision with Hand-Eye Calibration)

  • 김진대;이재원;신찬배
    • 한국정밀공학회지
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    • 제21권5호
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    • pp.83-83
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    • 2004
  • The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot′s end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

핸드-아이 보정과 능동 스테레오 비젼의 일반적 해석 (The General Analysis of an Active Stereo Vision with Hand-Eye Calibration)

  • 김진대;이재원;신찬배
    • 한국정밀공학회지
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    • 제21권5호
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    • pp.89-90
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    • 2004
  • The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot's end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.