Research On The Control Strategy Of Distributed Attitude And Orbit Cooperative Formation Of Micro-nano Satellites With Limited Inpu

With the development of computer technology,aerospace technology and microelectronics technology,micro-nano satellites are widely used in various fields of military and civilian land.The multiple micro-nano satellite formation has huge development potential and research value.Based on the multi-agent consensus theory,attitude and orbit coordinated control strategy of micro-nano satellite formations with input saturation has been studied in this thesis.The main contributions are summarized as follows.First,the time-varying formation control problem is investigated for the low thrust micronano satellite formation with switching topology.the low-gain formation control strategy is proposed by solving the parameter Riccati equation,which solves the problem of control input saturation during the formation process and ensures the semi-global stability of the closed-loop formation.With the fully distributed adaptive control strategy,the dependence on the information of the global communication topology is avoided.Based on the Lyapunov stability theory,the system stability is proved.Secondly,micro-nano satellite attitude and orbit coordinated control problem with external disturbances and parameter uncertainties is investigated.By decoupling the attitude and orbit coupling model into two subsystems that generate disturbances torque each other,adaptive control strategy is proposed to estimate and compensate the external disturbances,parameter uncertainties and own subsystem disturbances.Through the combination of dynamic surface technology and hyperbolic tangent function,the input saturation problem of micro-nano satellite position control is solved.It is realized that the micro-nano satellites that perform orbital maneuvers to achieve time-varying formations maintain attitude synchronization.Based on the Lyapunov stability theory,it is proved that the system is ultimately uniformly bounded and the principle of parameter selection is given.Thirdly,micro-nano satellite attitude and orbit coordinated with unknown satellite leader fault tolerance control problem is investigated.The proposed control protocol deals with faults of bias and unkonwb loss of effectiveness by means of adaptive fault-tolerant strategies.A neural network composed of adaptive technique is proposed to on-line approximate the unknown nonlinear functions.An distributed observer is established for a neutrally linear leader system whoes system matrix is not known exactly.Based on the Lyapunov stability theory,it is proved that the system is ultimately uniformly bounded and the principle of parameter selection is given.Finally,some simulations are maded by using Matlab/Simulink,furthermore the effectiveness of proposed methods are verified.