Nano satellite attitude determination with randomly delayed measurements.

In this paper, a novel algorithm is developed for Nano satellite attitude determination with delayed observations.The particularity of delayed measurements in attitude determination system is analyzed, and then employing a set of Bernoulli distributed random variables to build delayed sensor model. Based on the model, a modified EKF for nonlinear system is deduced by reorganizing the state update equation when data is time stamped or not, which does not increase the dimension of the state or measurement, and avoids the computation of singular matrix inversion. In addition, an adaptive estimation algorithm of measurement noise matrix is combined to reduce the impact of modeling uncertainty. Finally, simulation results demonstrate that the proposed algorithms lead to significantly improved performance compared with the traditional EKF and some delayed filters in the context of networked control systems. • Sensor delay model is established by using a group of Bernoulli random variables. • Filter developed is a modification of EKF, and can apply to delayed data with/without timestamp. • Attitude determination provides up to a twentyfold improvement relative to EKF without timestamp. [ABSTRACT FROM AUTHOR]