Advances in Space Research ( IF 2.177 ) Pub Date : 2021-01-19 , DOI: 10.1016/j.asr.2021.01.015 Liang Zhang; Peiqi Ge
For spacecraft hovering in low orbit, a high precision spacecraft relative dynamics model without any simplification and considering J2 perturbation is established in this paper. Using the derived model, open-loop control and closed-loop control are proposed respectively. Gauss's variation equations and the coordinate transformation method are combined to deal with the relative J2 perturbation between the two spacecraft. The sliding mode controller is adopted as the closed-loop controller for spacecraft hovering. To improve the control accuracy, the relative J2 perturbation is regarded as a known parameter term in the closed-loop controller. The external uncertainty perturbations except J2 perturbation are estimated by numerical difference method, and the boundary layer method is used to weaken the impact of chattering on the sliding mode controller. The open-loop control of spacecraft hovering with the relative J2 perturbation and without the relative J2 perturbation are simulated and compared, and the results prove that the accuracy of open-loop control with relative J2 perturbation has been significantly improved. Similarly, the simulation of the closed-loop control are presented to validate the effectiveness of the designed sliding mode controller, and the results demonstrate that the designed sliding mode controller including the derived relative J2 perturbation can guarantee the high accuracy and robustness of spacecraft hovering in long-term mission.
为了在低轨道上盘旋航天器，建立了一个不做任何简化并考虑J 2摄动的高精度航天器相对动力学模型。利用推导模型，分别提出了开环控制和闭环控制。高斯的变化方程和坐标变换方法相结合，以处理两个航天器之间的相对J 2摄动。滑模控制器被用作航天器悬停的闭环控制器。为了提高控制精度，相对J 2摄动被认为是闭环控制器中的已知参数项。J 2以外的外部不确定性摄动用数值差分法估计微扰，并采用边界层方法来减弱颤动对滑模控制器的影响。仿真和比较了具有相对J 2扰动和没有相对J 2扰动的航天器悬停的开环控制，结果证明，具有相对J 2扰动的开环控制的精度得到了显着提高。类似地，通过闭环控制仿真验证了所设计的滑模控制器的有效性，结果表明所设计的滑模控制器包括推导的相对J 2。 扰动可以确保长期飞行中的航天器盘旋的高精度和鲁棒性。