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.

本文研究了一种用于延迟观测的纳米卫星姿态确定的新算法。分析了姿态确定系统中延迟测量的特殊性，然后利用一组伯努利分布随机变量建立了延迟传感器模型。在该模型的基础上，通过对数据加时戳或不加时戳的状态更新方程进行重组，推导了非线性系统的改进EKF，不增加状态或测量的维数，并且避免了奇异矩阵求逆的计算。另外，结合了测量噪声矩阵的自适应估计算法，以减少建模不确定性的影响。最后，