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以连续小推力航天器为背景,提出了综合考虑星载加速度计和推力器在轨标定的自主导航方案。首先以精确姿态测量和引力梯度模型为标定参考信息源,建立了包含加速度计参数、推力器参数以及光压系数的完整参数测量模型;然后基于天文导航方法建立了自主导航系统状态模型和观测模型;表明各状态和参数的能观性后,采用了具备良好计算效率和鲁棒性的双重无迹卡尔曼滤波方法进行状态和参数联合估计。分析与数值仿真表明,该方法通过结合参数在轨标定直接提高了导航模型精度,在工程应用中具备可行性和有效性。
Based on the continuously small thrust spacecraft, an autonomous navigation scheme considering on-orbit calibration of spacecraft accelerometers and thrusters is proposed. Firstly, a complete parameter measurement model including accelerometer parameter, thruster parameter and light pressure coefficient is established by using accurate attitude measurement and gravitational gradient model as calibration reference information source. Then the state model and observation model of autonomous navigation system are established based on astronomical navigation method After observing the observability of the states and parameters, a dual unscented Kalman filter with good computational efficiency and robustness was used to estimate the joint states and parameters. The analysis and numerical simulation show that the proposed method can directly improve the accuracy of the navigation model by combining the on-orbit calibration with parameters, and is feasible and effective in engineering application.