Fault Detection and Identification of Actuator and Sensor in CubeSat Attitude Control System Using a Two-Stage Kalman Filter

This study focuses on modelling a satellite prototype designed to be manufactured with CubeSat standards and simulating attitude control to implement fault-tolerant control strategies. As part of the passive fault tolerance approach, the system is configured using a pyramid configuration with four reaction wheels. The ability to maintain attitude control using only three operational wheels is also analyzed. To increase reliability in case of sensor failure, an additional sensor is included with the physical integration of two redundant IMUs. A Two-Stage Kalman Filter is developed to detect sensor bias errors and increase the accuracy of system state estimation. In addition, a simple flip-flop mechanism is used to isolate faulty sensors and provides effective fault detection and switching. The Two-Stage Kalman Filter has shown strong performance in generating residuals indicating sensor bias errors.