An attitude and orbit determination and control system for a small geostationary satellite

• Main Author: Thopil, G. A.
• Other Authors: Steyn, W. H.
• Language: en
• Published: Stellenbosch : University of Stellenbosch 2008
• Subjects: Geostationary satellites; Orbit control; Attitude determination and control system; Dissertations > Electronic engineering; Theses > Electronic engineering; Electrical and Electronic Engineering
• Online Access: http://hdl.handle.net/10019.1/2284

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006. === An analysis of the attitude determination and control system required for a small geostationary satellite is performed in this thesis. A three axis quaternion feedback reaction wheel control system is the primary control system used to meet the stringent accuracy requirements. A momentum bias controller is also evaluated to provide redundancy and to extend actuator life. Momentum dumping is preformed by magnetic torque rods using a crossproduct controller. Performance of three axis thruster control is also evaluated. A full state Extended Kalman filter is used to determine attitude and body angular rates during normal operation whereas a Multiplicative Extended Kalman Filter is used during attitude manoeuvres. An analytical orbit control study is also performed to calculate the propellant required to perform station-keeping, for a specific sub-satellite location over a ten year period. Finally an investigation on the effects caused by thruster misalignment, on satellite attitude is also performed.