Geng Yuanzhuo, Li Chuanjiang, Guo Yanning, Biggs James D
Department of Control Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Department of Control Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China.
ISA Trans. 2020 Feb;97:401-414. doi: 10.1016/j.isatra.2019.07.026. Epub 2019 Jul 30.
Repointing maneuvers of a spacecraft in staring mode are investigated where the optical axis is required to align with the target orientation. Different from traditional three-axis reorientation maneuvers, the rotation about the optical axis is free of constraints for repointing maneuvers. Both static target observation and moving target detection constraints are considered. The problem is then formulated as a finite-time horizon optimal control problem with nonlinear terminal constraints. A simple and efficient state-dependent Riccati equation(SDRE) based dynamic programming approach is applied to tackle this nonlinear optimal control problem. The convergence of the attitude from initial conditions to the desired terminal constraint is rigorously proved for the first time. Considering the inability of the SDRE method to deal with the problem of large angle maneuvers, an improved SDRE approach combined with a waypoint is proposed to enhance control performance. Finally, numerical investigations are conducted and compared with the real optimal solutions obtained by using the optimization software.
研究了处于凝视模式的航天器的重新指向操作，其中要求光轴与目标方向对齐。与传统的三轴重新定向操作不同，对于重新指向操作，绕光轴的旋转没有约束。同时考虑了静态目标观测和移动目标检测约束。然后将该问题表述为具有非线性终端约束的有限时间范围最优控制问题。应用一种基于简单高效的状态依赖 Riccati 方程（SDRE）的动态规划方法来解决这个非线性最优控制问题。首次严格证明了姿态从初始条件收敛到期望的终端约束。考虑到 SDRE 方法无法处理大角度机动问题，提出了一种结合航路点的改进 SDRE 方法以提高控制性能。最后，进行了数值研究，并与使用优化软件获得的实际最优解进行了比较。
