双星编队构形保持抗干扰容错控制

Anti-disturbance and fault-tolerant control of dual-satellite formation configuration maintenance

为解决系统模型误差、外部干扰以及执行器故障引起的双星编队轨道控制精度低、稳定性差问题,设计一种基于观测器的抗干扰容错线性二次型调节器(LQR)控制策略。首先,根据编队双星相对运动动力学模型,设计基于双比例积分自适应律的增广观测器,同时实现对系统状态、间歇故障与快速时变故障、可建模干扰的快速精确估计,并采用H∞优化技术抑制不可建模干扰对控制系统的影响。其次,采用Lyapunov稳定性理论,保证动态误差系统渐近稳定。然后,在控制器中引入未知动态估计信息的前馈补偿项,设计闭环反馈抗干扰容错LQR控制律。最后实验结果表明,相比文献中控制方法,本文所提方法的编队卫星相对位置控制精度提高49.93%,验证了所设计的抗干扰容错LQR控制律的优越性,能够为双星编队构形保持提供精确控制策略。

To solve the problem of low precision and poor stability of dual-satellite formation orbit control caused by system modeling errors,external disturbances,and actuator faults,this paper proposes an antidisturbance and fault-tolerant linear quadratic regulator(LQR)control strategy based on an observer.First,according to a relative motion dynamic model of two satellites,an augmenting observer is designed based on the double proportional integral adaptive law,which not only can estimate intermittent faults and fast time-varying faults,but can also simultaneously estimate the system state and disturbance quickly and accurately.Regarding unmodeled disturbances,the optimization technology is used to suppress their influence on the control system.Second,the existence condition and design method of the observer are given using the linear matrix inequality(LMI)technique.The asymptotic stability of the dynamic error system is guaranteed using Lyapunov stability theory.Then,a closed-loop feedback fault-tolerant and anti-inter⁃ference LQR control law is designed by adding feedforward compensation to the controller using unknown dynamic estimation information.Finally,the experimental results show that the proposed method can ac⁃curately and quickly track external interferences,actuator faults,and system states.Compared with the control methods reported in the literature,the proposed method significantly enhances the accuracy of fault estimation and improves by 49.93%the relative position control accuracy of formation satellites.This ver⁃ifies the superiority of the anti-interference fault-tolerant LQR control law,which can provide an accurate configuration maintenance control strategy for dual-satellite formation configuration maintenance.