Attitude Synchronization For Multiple Spacecraft Under Limited Inter-spacecraft Communication

In recent years,many attention has been paid to the study of attitude synchronization for a group of spacecraft.In some attitude synchronization missions,the inter-spacecraft communication resources are limited due to the poor performance of inter-spacecraft communication equipment and long inter-spacecraft distance.Moreover,the adverse effects of model uncertainties and external disturbances make the performance of the attitude synchronization system unsatisfying.Hence,this paper investigated the attitude synchronization control problem of a group of spacecraft in the presence of limited interspacecraft communication,model uncertainties and external disturbances.The main researches are as following:Based on the undirected inter-spacecraft communication topology,a distributed adaptive sliding-mode event-triggered control scheme for attitude synchronization and tracking scheme of a group of spacecraft is proposed.Under the proposed event-triggered strategy,the attitude information of spacecraft only need to be transmitted to its neighboring spacecraft at some discrete triggered times when a defined event-triggered error exceeds a state-dependent threshold.The zero-order holds are used to hold the last transmitted information for the neighboring spacecraft at the controller until the next transmission is received.Then,another distributed adaptive sliding-mode event-triggered control scheme for attitude synchronization and tracking scheme of a group of spacecraft is proposed to solve the attitude synchronization problem of in the presence of limited inter-spacecraft communication,model uncertainties and external disturbances.Under the proposed control law,all the spacecraft can align their attitudes and track the desired attitude trajectory simultaneously.The stability of the resulting closed-loop systems can be guaranteed by application of the Lyapunov function.Finally,simulation results demonstrate the efficiency of the proposed event-triggered attitude synchronization control algorithms,and data to be sent over the communication channel among spacecraft under the proposed control scheme is greatly reduced.A logarithmic quantizer is employed to quantize the signal of transmitted state information,and a distributed adaptive sliding mode attitude synchronization and tracking control scheme is proposed to deal with the effects on control performances caused by quantization errors.Under the proposed scheme,when the current quantized attitude information is different from its previous one,the attitude information will be sent over the inter-spacecraft communication channel to its neighbors.The zero-order holds are used to hold the last transmitted information for the neighboring spacecraft at the controller until the next transmission is received.Then,another distributed adaptive sliding-mode event-triggered control scheme for attitude synchronization and tracking scheme of a group of spacecraft is proposed to solve the attitude synchronization problem of in the presence of limited inter-spacecraft communication,model uncertainties and external disturbances.Under the proposed control law,all the spacecraft can align their attitudes and track the desired attitude trajectory simultaneously.The stability of the resulting closed-loop systems can be guaranteed by application of the Lyapunov function.Finally,simulation results demonstrate the efficiency of the proposed event-triggered attitude synchronization control algorithms,and data to be sent over the communication channel among spacecraft under the proposed control scheme is greatly reduced.