• 제목/요약/키워드: initial alignment

검색결과 191건 처리시간 0.03초

Development of the Real-time Initial Alignment Algorithm using the Kalman Filter

  • Oh, Sang-Heon;Hwang, Dong-Hwan;Lee, Sang-Jeong
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.61.2-61
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    • 2001
  • The purpose of the initial alignment of a SDINS is to get a coordinate transformation matrix from the body frame to the navigation frame. The initial alignment is one of the most important processes in the navigation system since its error has a large influence on the navigation solution. In this paper, a real-time initial alignment algorithm for the SDINS is developed using the Kalman filter. The steady state error analysis is performed for the developed Kalman filter technique and the gyrocompass loop method. The performance of the developed alignment method is compared with the gyrocompass loop method through the real-time alignment experiments.

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UKF를 적용한 레이저 관성항법장치의 외란에 대한 초기정렬 성능분석 (Performance Analysis in Disturbance on Initial Alignment of Laser Inertial Navigation System Using Unscented Kalman Filter)

  • 오주현
    • 한국군사과학기술학회지
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    • 제17권4호
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    • pp.537-543
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    • 2014
  • RLG(Ring Laser Gyroscope) is a main device of LINS(Laser Inertial Navigation System). RLG has the lock-in region in which there is no output signal. To alleviate the lock-in problem, a mechanical oscillation, the dither motion, is applied on RLG. A LPF(Low Pass Filter) is usually used on the output of RLG and accelerometer to remove the noise that is made by the dither motion. When the LINS is induced the disturbance during the initial alignment, it takes more time on alignment due to the use of the LPF and a fixed gain controller. In this paper, an initial alignment using UKF(Unscented Kalman Filter) is designed and analysed. Analysis include comparison between conventional initial alignment loop using fixed gain type controller and proposed initial alignment using UKF. Moreover, Disturbance inducing test results are demonstrated.

항공기 Run-Up 진동 환경에서의 관성항법장치 초기 정렬 방법 설계 및 평가 (Design and Evaluation of INS Initial Alignment under Vibration Environment of Aircraft Run-up)

  • 유해성;이인섭;오주현;김천중;박흥원
    • 제어로봇시스템학회논문지
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    • 제21권7호
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    • pp.691-698
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    • 2015
  • Inertial Navigation Systems (INS) are widely used as the main navigation device for aircraft. To get the initial attitude, the INS requires the initial alignment before navigation starts. An aircraft also needs an engine test procedure that causes some vibrations before flight. An INS can't be aligned in a vibration environment so the initial alignment is performed before the aircraft engine test. Therefore, the initial alignment time of an INS has been a major factor in limiting an aircraft's takeoff response time. In this paper, we designed an initial alignment algorithm that can be executed even in disturbances such as aircraft run-up. We demonstrated verification of the algorithm that is embedded on the real INS and testing methods to evaluate the alignment of the INS. We also analyzed the test results of the proposed initial alignment algorithm that is performed during a real aircraft run-up.

항공기에서 투하되는 수중운동체의 초기정렬기법 연구 (A Study of An Initial Alignment Method of Underwater Vehicle Dropped from Aircraft)

  • 류동기;김삼수
    • 한국군사과학기술학회지
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    • 제6권1호
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    • pp.21-29
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    • 2003
  • The Strap Down Inertial Measurement Unit(SDIMU) is recently used for the sensor package of the modern underwater vehicles such as torpedoes and unmanned underwater-vehicles. For using SDIMU, an initial alignment must be carried out before the fire or navigation stage. The general initial alignment methods require that a mother vehicle Is a stationary condition or the Inertial Navigation System(INS) of vehicle is received the specific of data navigation from the mother vehicle. But an underwater vehicle dropped from aircraft is hard to satisfy above both necessary conditions of the general initial alignment. So, we suggest a new strap down initial alignment method of an underwater vehicle dropped from aircraft without using any aided sensors. The highlight point of this method is that a period of initial alignment is not before the fire but during running stage to fix alignment error. And we verify it by analyzing various data of S/W simulations, Hardware In the Loop Simulation(HILS) tests and sea trials.

적응형 시간지연 보상을 통한 관성항법장치 급속초기정렬기법 (Rapid Initial Alignment Method of Inertial Navigation System Using Adaptive Time Delay Compensation)

  • 이형섭
    • 전기학회논문지
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    • 제67권3호
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    • pp.433-439
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    • 2018
  • In this paper, a SDINS(strapdown inertial navigation system) rapid initial alignment technique with adaptive time delay compensation is proposed. The proposed method consists of two steps. In first step, misalignment and data latency are estimated by conducting pre-transfer alignment. Then, hybrid alignment is designed to rapidly find the misalignment changes induced by pyro-shock. To improve the performance of hybrid alignment, adaptive time delay compensation method is suggested. We verify the performance improvement of the proposed alignment scheme comparing with the conventional transfer alignment method by van test. The test result shows that the proposed alignment technique improves alignment performance.

연속발사 충격에 강인한 SDINS 신속 초기정렬기법 설계 (Design of SDINS Rapid Initial Alignment Technique Robust to the Pyro-shock in Multi-Launch Rocket System)

  • 이형섭;한경준;이상우;유명종
    • 전기학회논문지
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    • 제65권6호
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    • pp.1038-1044
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    • 2016
  • In this paper, a SDINS(Strapdown Inertial Navigation System) rapid initial alignment technique robust to the pyro-shock in multi-launch rocket system is proposed. The proposed method consists of three steps. Firth, transfer alignment is performed to estimate misalignment between MINS(Master INS) and SINS(Slave INS), and the estimated misalignment is written in the memory when transfer alignment is completed. Next, the pre-filtering process is performed to get rid of the acceleration error induced by launcher vibration. Finally, the horizontal alignment is performed to compensate misalignment variation caused by pyro-shock. We verified the performance of the proposed alignment method comparing with the conventional transfer alignment method. The simulation shows that the proposed initial alignment technique improves alignment performance.

레이저 관성항법장치 초기정렬 성능 분석 (Performance Analysis on the Initial Alignment of Laser Inertial Navigation System)

  • 김현석;김천중;이태규
    • 한국군사과학기술학회지
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    • 제12권5호
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    • pp.622-635
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    • 2009
  • Laser Inertial Navigation System(LINS) consists of Ring Laser Gyroscopes(RLG) and accelerometers. RLG has a lock-in region in which there is zero output for input angular rates less than about 0.1deg/sec. The lock-in region is generated by the imperfect mirrors in RLG. To avoid the lock-in region, a sinusoidal motion called dither motion is applied on RLG. Therefore this dither motion is measured by RLG/accelerometer even if at a stop state. In this situation, the performance on the initial alignment of LINS can be degraded. In this paper, we analyze the performance on the initial alignment of LINS theoretically and experimentally. Analysis results include how dither motion, the pre-filter and the corner frequency in alignment loop affects the performance on the initial alignment of LINS.

치아배열을 위한 교정용 탄선의 선택에 대한 고찰 (CLINICAL CONSIDERATION IN THE CHOICE OF ALIGNMENT ARCHES)

  • 박의웅;김상철
    • 대한치과교정학회지
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    • 제19권3호
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    • pp.79-86
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    • 1989
  • The wires for initial alignment purposes require a combination of excellent strength, excellent springiness, and a long rang of action. The variables in selecting appropriate arches for alignment are the arch wire material, its diameter, and the distance between attachments. The principle that there should be 0.02 inch clearance for initial wires means that an .016 diameter wire is the largest that should be considered for initial alignment in the .018 slot system. The three major possibilities for alignment arches are multistranded steel wires, nickel-titanium wires, and single-stranded steel wires with loops. The excellent choice for initial alignment in .018 bracket is .014 steel wire with loops.

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스트랩다운 관성항법시스템의 초기정렬 알고리즘 구현 (Implementation of an Initial Alignment Algorithm for a Stapdown Inertial Navigation system)

  • 김종혁;문승욱;이시호;김세환;황동환;이상정;나성웅
    • 제어로봇시스템학회논문지
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    • 제6권2호
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    • pp.138-145
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    • 2000
  • In this paper an initial alignment algorithm for a strapdown inertial navigation system is implemented using a RISC CPU board. The algorithm computes roll pitch and yaw angles of the direction cosine matrix utilizing measured components of the specific force and earth rate when the navigation system is stationary. The coarse alignment algorithm is performed first and then the fine alignment algorithm containing a 3rd-order gyrocompass loop follows. The experimental set consists of an IMU a CPU board and a monitoring system Experimental results show that the implemented algorithm can be utilized in navigation systems.

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In-Flight Alignment Algorithm Using Uplinked Radar Data Including Time Delay

  • Park, Chan-Ju;Kim, Heun-Beik;Song, Gi-Won
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.56.1-56
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    • 2001
  • Initial attitude error is one of the large error sources in the navigation errors of SDINS. And it is important to decide the initial attitude of SDINS. The method, like a self-alignment or a transfer alignment method, is required to a precise INS. If we do not have a precise INS, we should get large attitude error. After performing the initial alignment, a vehicle has the initial attitude error. Therefore, it results in navigation error due to the initial attitude error. But, if we use position information during flight, we could estimate and compensate a vehicle attitude error. So, we can maintain a precise attitude in spite of existing the initial attitude error. Using the uplinked position information from a land-based radar system, the new algorithm estimates the attitude of the SDINS during flight ...

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