A Factor Graph-Based Attitude Determination Approach for Microsatellite with Star Sensor and Gyros

Attitude determination is an important part of microsatellite attitude control system. Its determination accuracy directly affects microsatellite's attitude control performance. Hence, a novel attitude determination approach is presented in this work for microsatellites with star sensor and gyros fixed. The factor graph representing the probabilistic graphical model as a bipartite graph is applied to solve the attitude estimation problem. This allows multi-rate, asynchronous, and possible delayed measurements to be incorporated in a natural way. An incremental smoothing algorithm is then proposed to achieve optimal estimation. Simulation results are finally presented to verify that the proposed approach can significantly improve the attitude determination accuracy.