Department News

Attitude Control System Overview of KAISTSAT-4

Seminar Date 2000-10-18
Author
윤두희
Date
2000-10-18
Views
1027
1.제목:Attitude Control System Overview of KAISTSAT-4


2.연사: 이현우 연구원 (한국과학기술원 인공위성센터)


3.일시: 2000년 7월 14일 (금요일) 오후 4시 30분


4.장소: 301동 1512호


5.내용:


After the successful launch and operation of the 3-axis stabilized KITSAT-3 micro-satellite, the Satellite Technology Research Center (SaTReC) of KAIST is developing the KAISTSAT-4, the upgraded version of KITSAT-3, which is due to launch in 2002. The attitude control system of KAISTSAT-4 is proposed to accommodate payloads requiring higher attitude accuracy and stability. The main payload will perform space science experiments by measuring far ultra violet (FUV) radiation with an FUV imaging spectrograph (FIMS).


For the successful operation, it is required to point the FIMS at various celestial targets with 0.5 degree of pointing and 5 arc minutes of attitude knowledge accuracy. The attitude control system is composed of high performance components to meet the payload requirements.


Two star sensors are mounted on the roll axis that is the same direction of the FIMS. The star trackers provide inertial reference attitude to within 10 to 60 arc seconds (). There are four fiber optic gyros used for updating the attitude by the Kalman filter with the help of the attitude sensors such as star trackers, sun sensors and magnetometers. Two three-axis magnetometer and three-axis magnetic torquer coils are used for momentum unloading of the wheels and spin rate control for the initial stage after the separation. The magnetometer is a flux-gate type sensor that has a measure range of -60 to +60T and a 30nT resolution. The magnetic torquer coil is wound on each solar panel and a feedback circuit linearly controls the current flowing into the coil in order to generate the magnetic dipole up to 10. One analog sun sensor and three coarse sun sensors are employed to estimate the coarse three-axis attitude information with the help of the magnetometer. In addition, the coarse sun sensors are essential to protection of the FIMS from a direct exposure to the sunlight.





6. 연사 약력 :


1990 한국과학기술원, 전자공학과, B.S.


1991 University of Surrey, England, Satellite Communication, M.Sc.


1994-현재 한국과학기술원, 전자공학과, 박사과정





7. 연락처 : 기계항공공학부 기창돈 교수 (전화 : 880-1912)