Abstract: Aiming at the autonomously relative motion between two spacecraft traveling along arbitrary high elliptical orbits around a common central primary body,an adaptive control schemes based on the precise motion model of system.For the general nonlinear model of the relative motion between spacecraft,the model was reconstructed by introducing the virtual variables.Considering the input constraints for spacecraft rendezvous and docking,an auxiliary design system was utilized to analyze the effect of the input constraints in the nonlinear model,whicl could improve the control performance and guarantee the asymptotic stability of the closed-loop system.In addition,for the parametric uncertainty arising from the unknown orbital motion of the target spacecraft,a linear parameterized approximation was realized with binomial series expansion method.The proposed adaptive backstepping controller could guarantee the ultimate boundedness of the closed-loop signals as well as the adaptive estimates of the unknown parameters.For the case of both uncertainty and input constraints in the motion model,a design method combining the algebraic parameterized approximation and the auxiliary design system was used to analyze and address the effect of input constraints.Numerical studies were iused to compare the performance and demonstrate the effectiveness of the proposed adaptive controllers.

Key words: relative motion, adaptive control, uncertainty, input constraint, nonlinear system, spacecraft

摘要： 针对围绕同一中心天体的任意高椭圆轨道飞行的航天器之间的自主相对运动问题,提出基于系统相对运动模型的航天器自适应控制策略。首先,对适用于任意航天器相对运动的一般性非线性模型,通过设计系统内部虚拟变量对模型进行重构。其次,针对非线性系统下航天器交会对接输入约束问题,基于重构的非线性模型,通过设计辅助控制系统,分析和解决控制输入约束的影响,在提高控制性能的同时保证闭环系统的渐近稳定性。此外,由目标星未知轨道运动引起的模型非线性参数项不确定性问题,通过二项式级数扩展方法实现线性参数化近似,结合提出的自适应反步控制器,能够保证闭环信号以及未知参数估计的最终有界性。对于同时存在模型不确定性与控制输入约束的问题,采用代数参数化线性近似与辅助控制系统相结合的设计方法,能够分析和处理控制加速度约束的影响。最后,通过对几个案例的仿真分析,比较和验证了所提出的自适应控制策略的有效性。

关键词: 相对运动, 自适应控制, 不确定性, 输入约束, 非线性系统, 航天器