Abstract: Fault detection is important in satellite attitude control. Some great disturbance and model uncertainty make this task a difficult work. In the past, fault, input and disturbance are seen as a generalized input. Then residual is made close to fault by making infinite norm of gain minimum. In the past, the importance of fault, input and disturb is equal, which was not the best choice. So a novel method for designing a filter should be put out. The fault detection filter is designed by using the linear matrix inequality (LMI). This filter contains three different indexes. It is applied in an orbiting satellite model on witch fault may happen in its jet actuator. Parameters of the filter are calculated and simulation is done. Although three indexes can not be far less than 1, this filter still can be uesd for fault detection by using adapitve threshold. The result of the simulation is demonstrated.

Key words: Fault detection, Satellite, Attitude control, Linear matrix inequality(LMI), Robust