An adaptive relative pose controller for docking ports of two uncertain spacecraft in autonomous rendezvous and docking is developed. A novel relative translational and rotational model represented in the chaser body-fixed frame is derived first based on the classical Newton–Euler equations. Based on the proposed model, a six-degrees-of-freedom adaptive control law is presented based on norm-wise estimations for the unknown parameters of two spacecraft to decrease the online computational burden. Meanwhile, an adaptive robust control input is designed by introducing an exponential function of states to improve the response performance with respect to the traditional adaptive robust control. Moreover, a linear antiwindup compensator is employed to ensure the bounded performance of the control inputs. The explicit tuning rules for designing parameters are derived based on the stability analysis of the closed-loop system. It is proved in Lyapunov framework that all closed-loop signals are always bounded and the pose tracking error ultimately converges to a small neighborhood of zero. Simulation results validate the performance of the proposed robust adaptive control strategy.

中文翻译：

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空间近距离交会中对接端口的饱和自适应相对运动协调

开发了一种用于自主交会对接中两个不确定航天器对接端口的自适应相对位姿控制器。首先基于经典的 Newton-Euler 方程推导出以追踪器身体固定框架表示的新型相对平移和旋转模型。基于所提出的模型，提出了一种六自由度自适应控制律，基于对两个航天器未知参数的范数估计，以减少在线计算负担。同时，通过引入状态指数函数来设计自适应鲁棒控制输入，以改善传统自适应鲁棒控制的响应性能。此外，采用线性抗饱和补偿器来确保控制输入的有界性能。设计参数的显式整定规则是基于闭环系统的稳定性分析推导出来的。在李雅普诺夫框架中证明，所有闭环信号总是有界的，位姿跟踪误差最终收敛到一个小的零邻域。仿真结果验证了所提出的鲁棒自适应控制策略的性能。