• Title/Summary/Keyword: Attitude Control System

Search Result 707, Processing Time 0.035 seconds

Star Visibility Analysis for a Low Earth Orbit Satellite

  • Yim, Jo-Ryeong;Lee, Seon-Ho;Yong, Ki-Lyuk
    • Bulletin of the Korean Space Science Society
    • /
    • 2008.10a
    • /
    • pp.28.2-28.2
    • /
    • 2008
  • Recently, star sensors have been successfully used as main attitude sensors for attitude control in many satellites. This research presents the star visibility analysis for star trackers and the goal of this analysis is to make sure that the star tracker implementation is suitable to the mission profile and scenario and satisfies the requirement of attitude orbit control system. As a main optical attitude sensor imaging stars, accomodations of a star tracker should be optimized in order to improve the probability of the usage by avoiding the blinding (the unavailability) by the Sun and the Earth. For the analysis, a statistical approach and a time simulation approach are used. The statistical approach is based on the generation of numerous cases, to derive relevant statistics about Earth and Sun proximity probabilites for different lines of sight. The time simulation approach is performed for one orbit to check the statistical result and to refine the statistical result and accomodations of star trackers. In order to perform simulations first of all, an orbit and specific mission profiles of a satellite are set, next the earth proximity probability and the sun proximity probability are calculated by considering the attitude maneuvers and the geometry of the orbit, and then finally the unavailability positions are estimated. As a result, the optimized accomodations of two star trackers are suggested for the low earth orbit satellite.

  • PDF

Implementation of the 3 axes Attitude Control Sensor System (3축 자세 제어용 센서 시스템의 구현)

  • Jeong, Jong-Won;Choi, Woo-Jin;Ji, Suk-Jun;Lee, Ki-Young;Lee, Joon-Tark
    • Proceedings of the KIEE Conference
    • /
    • 2001.07d
    • /
    • pp.2329-2331
    • /
    • 2001
  • In this paper, were developed the 3 axes attitude control sensor system to control and monitoring the moving object. The proposed sensor system has been studied in Japan, America for a year ago. But it is high expensive and has a difficulty in application. To overcome these problems, proposed the 3 axes attitude control sensor system is low cost and easily applied. Proposed sensor system is equipped with the 3 gyro sensors, 2 tilt sensors and 3 MR sensors using 80C51 microprocessor for signal processing. It's output value transmit at long distance using RS232 serial communication protocol. We expect this system shall have a good performances in many applications of control and monitoring the moving object.

  • PDF

Development of a Hardware-In-Loop (HIL) Simulator for Spacecraft Attitude Control Using Momentum Wheels

  • Kim, Do-Hee;Park, Sang-Young;Kim, Jong-Woo;Choi, Kyu-Hong
    • Journal of Astronomy and Space Sciences
    • /
    • v.25 no.4
    • /
    • pp.347-360
    • /
    • 2008
  • In this paper, a Hardware-In-the-Loop simulator to simulate attitude control of space craft using momentum wheels is developed. The simulator consists of a spherical air bearing system allowing rotation and tilt in all three axes, three momentum wheels for actuation, and an AHRS (Attitude Heading Reference System). The simulator processes various types of data in PC104 and wirelessly communicates with a host PC using TCP/IP protocol. A simple low-cost momentum wheel assembly set and its drive electronics are also developed. Several experiments are performed to test the performance of the momentum wheels. For the control performance test of the simulator, a PID controller is implemented. The results of experimental demonstrations confirm the feasibility and validity of the Hardware-In-the-Loop simulator developed in the current study.

Nonlinear Attitude Control for Uncertain Quad-rotors Using a Global Approximation-Free Control Scheme (GAFC 비선형 제어기법을 적용한 쿼드로터의 자세 및 고도제어)

  • Kim, Young-Ouk;Park, Seong-Yong;Leeghim, Henzeh
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.22 no.10
    • /
    • pp.779-787
    • /
    • 2016
  • A nonlinear control law for the quad-rotor of a low-complexity, global approximation-free from system uncertainties and external disturbances are described in this paper. The control law guarantees convergence to a small bounded error using a prescribed performance function. The stability of the proposed nonlinear control system is also proven by the Lyapunov stability theorem. The advantage of this technique is that it has a simpler form than any other nonlinear compensators and is applicable to any nonlinear systems without precise knowledge of the systems. In this paper, the proposed approach is applied to attitude/altitude control of a quad-rotor. Numerical simulations are performed to investigate the proposed nonlinear attitude control law by applying it to an uncertain quadcopter system with external disturbances.

SDINS Equivalent Error Models Using the Lyapunov Transformation (Lyapunov 변환을 이용한 SDINS 등가 오차모델)

  • Yu, Myeong-Jong;Lee, Jang-Gyu;Park, Chan-Guk
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.8 no.2
    • /
    • pp.167-177
    • /
    • 2002
  • In Strapdown Inertial Navigation System(SDINS), error models based on previously proposed conversion equations between the attitude errors, are only valid in case the attitude errors are small. The SDINS error models have been independently studied according to the definition of the reference frame and of the attitude error. The conversion equations between the attitude errors applicable to SDINS with large attitude errors are newly derived. Lyapunov transformation matrices are also derived from the obtained results. Furthermore the general method, which is independent of the attitude error and the reference frame to derive SDINS error model, is proposed using the Lyapunov transformation.

High-Altitude Terminal Guidance and Control Loop Design Using Thrust Vector Control (추력벡터제어를 이용한 고고도 종말 유도조종 루프 설계)

  • Jeon, Ha-Min;Park, Jongho;Ryoo, Chang-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.50 no.6
    • /
    • pp.393-400
    • /
    • 2022
  • The Divert and Attitude Control System(DACS) used in high-altitude engagements is expensive and complex. In this paper, we design a high-altitude terminal guidance and control loop of guided-missile equipped with a Thrust Vector Control(TVC) that is less expensive and simpler than DACS. The proposed system utilizes a quaternion feedback control technique to track the thrust attitude command converted from the acceleration command of true proportional navigation guidance. The performance analysis of the proposed terminal guidance and control loop is conducted through engagement simulations against ballistic targets at a high altitude.

ANALYSIS OF THE HAUSAT-2 ATTITUDE CONTROL (HAUSAT-2 자세제어 성능 해석)

  • Lee Byung-Hoon;Kim Soo-Jung;Chang Young-Keun
    • Bulletin of the Korean Space Science Society
    • /
    • 2005.04a
    • /
    • pp.133-137
    • /
    • 2005
  • This paper describes the design and performance verification of a pitch momentum bias control system being built by students at the Space System Research Laboratory(SSRL). HAUSAT-2 ADCS(Attitude Determination and Control of Subsystem) op-elation mode is divided into two parts, initial mode and on-orbit mode. This paper describes design of the HAUSAT-2 performance of attitude control results using pitch momentum bias control method in initial mode and on-orbit mode and momentum dumping method.

  • PDF

Recent Progress in R&D and Prospect of Divert and Attitude Control System(DACS) (궤도천이 및 자세제어 시스템의 연구개발 동향과 전망)

  • Kim, Seongsu;Huh, Hwanil
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.16 no.6
    • /
    • pp.62-72
    • /
    • 2012
  • Divert and attitude control system(DACS) plays an important role for orbit transfer and attitude control, and therefore becomes important subject for recent space vehicle and Precision Guided Missile(PGM) development. To develop DACS system, main research areas include shape combination of pintle and nozzle to maximize thrust change, and reduction of aerodynamic pintle load to minimizle pintle driving force, and development of multi-axis control algorithm. In this paper, introduction, classification, and overseas/domestic research and development program, and prospects of DACS are reviewed and summarized.

Design and Verification of Satellite Attitude Control system for Roll Maneuver (인공위성의 Roll축 자세제어시스템 설계 및 검증)

  • 김희섭;김기석;안재명;김유단;최완식
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.5 no.3
    • /
    • pp.370-378
    • /
    • 1999
  • KOMPSAT is a three-axis stabilized light weight satellite, and one of the main mission objectives of the KOMPSAT is to conduct scientific and technological analysis in the areas of high resolution imaging and ocean color imaging. This kind of mission requires the satellite to roll up to 45 degrees. Bang-bang control for this rolling maneuver may activate the flexible modes, and therefore cause satellite pointing performance degradation. To deal with this problem, the roll attitude control system, especially for the science mode and maneuver mode of the KOMPSAT, is first verified by numerical simulation. And the open-loop control law for roll maneuver is proposed by use of series expansion and optimization. The proposed control law is applied to KOMPSAT to see its effectiveness.

  • PDF

Numerical Investigation of On-orbit Thermal Characteristics for Cube Satellite with Permanent Magnet Attitude Stabilization Method (영구자석 안정화 자세제어 방식이 적용된 큐브위성의 열적 특성분석)

  • Kang, Soo-JIn;Jung, Hyun-Mo;Oh, Hyun-Ung
    • Journal of Aerospace System Engineering
    • /
    • v.7 no.3
    • /
    • pp.26-32
    • /
    • 2013
  • Passive attitude stabilization method has been widely usde for attitude determination and control of cube satellite due to its advantage of system simplicity. The permanent magnet installed on the cube satellite passively controls the attitude of the satellite such that the satellite is aligned with the earth magnetic field. In this paper, on-orbit thermal behavior of the cube satellite with the permanent magnet attitude stabilization method has been investigated through on-orbit thermal analysis. THe orbit profile obtained from the aforementioned attitude control method has been reflected in the analysis. The analysis results indicate that the thermal design proposed in this study is effective for satisfying the temperature requirements of the commericial mission equipments.