Constrained Attitude Coordination Control Of Spacecraft Formation Flying

Spacecraft formation flying(SFF)has the advantages of high system reliability and flexibility,which is important for conducting earth monitoring,searching for earth-like planets,and conducting cutting-edge space scientific experiments.In the complicated and changeable space environment,the coordinated control of SFF is an important guarantee to carry out formation missions.This dissertation considers the needs of spaceflight applications and investigates the constrained attitude cooperative control methods of SFF systems in the presence of the finite-time convergence,communication delays,stochastic uncertainties,and flexural component vibrations.The main contents are as follows:In the presence of external disturbances,a robust control method for the finite-time constrained attitude cooperative control problem of rigid spacecraft formations is proposed when the desired informations are globally known.First of all,by combining the artificial potential function method with the nonsingular fast terminal sliding mode control method,a new nonsingular fast terminal sliding mode surface based on the rotation matrix is designed.Then,an almost global constrained attitude cooperative control method is proposed based on the super-twisting control,which ensures the robustness of the spacecraft formation system and can complete attitude cooperation in a finite time.Finally,based on the Lyapunov stability theory,the sufficient conditions are strictly derived for the spacecraft formation to guarantee the almost globally finite-time constrained attitude cooperation with disturbances.In the presence of the communication delay,a robust control method for the finite-time constrained attitude cooperative control problem of rigid spacecraft formations is proposed when the desired information is partially unknown.Since some spacecraft cannot obtain the information of the leader,a communication delay finite-time distributed observer is designed based on the Artstein’s transformation method and the finite-time stability theory.Then,a rotation matrix-based leader-following finite-time constrained attitude cooperative control method is proposed.Finally,the sufficient conditions are strictly derived for spacecraft formation to guarantee the almost globally finite-time constrained attitude cooperation with the communication delay based on the Lyapunov stability theory.The constrained attitude cooperative control problem of rigid spacecraft formations with stochastic uncertainties is investigated under undirected connected communication topology.Aiming at solving the problem,two cooperative control methods are proposed.In the case where the desired information is globally known,by combining the behavioral formation approach and the modified super-twisting control,a constrained attitude cooperative control method is proposed and sufficient conditions for the closed-loop stochastic spacecraft formation system to achieve mean square bounded attitude cooperation are rigorously derived.In the case that the desired information is partially unknown,a leader-following constrained attitude cooperative control method is proposed and the stability conditions of the closed-loop leader-following SFF system with stochastic uncertainties are analyzed.For the constrained attitude cooperative control problem of flexible spacecraft formations,cooperative control strategies are proposed under directed connected communication topology.With the assumption that only deterministic perturbations exist,based on artificial potential functions,the super-twisting control and the adaptive control,the constrained attitude cooperative control problems in the case of known and unknown upper bound of deterministic perturbation are studied respectively.Then,in the presence of complex perturbations,based on the finite-time distributed observer and the separation theorem,the constrained attitude cooperative control problems in the case of the desired information is known globally and locally are studied respectively.In conclusions,this dissertation studies the constrained attitude cooperative control of rigid spacecraft formations subject to external disturbances and communication delay under the fast convergence requirement sequentially,and studies the constrained attitude cooperative control of rigid spacecraft formations and flexible spacecraft formations sequentially in the presence of stochastic uncertainties.These researches on the constrained attitude cooperative control can contribute to the development of the spacecraft formation control techniques.