Research On Planning Method Of Multi-satellite With Cooperative Earth Observation Mission

With the deepening of the application of earth observation,the task demand rises sharply,and the task demand is becoming more and more complex.From point target observation to regional target coverage,and then to mobile target monitoring,the types of observation targets are gradually expanded.At the same time,complex observation requirements such as multi frequency,multi-mode and multi-sensor are also gradually increasing.In many cases,a single satellite cannot complete these complex observation requirements.Although the number of earth observation satellites is also increasing,satellite resources are still relatively tight compared with the faster growing mission requirements,and the complexity of many mission requirements cannot be solved by the increase of the number of satellites.In this context,multi satellite cooperative earth observation has become an effective means to solve the problem.Through the cooperation between multiple satellites carrying the same load,the multi frequency observation of the same target can be realized,to improve the resolution of the target.Through the cooperation between multiple satellites carrying different types of loads,multi-type sensor observation can be realized,to obtain different types of observation data of the same target.To effectively cooperate with multi satellites for mission observation,mission planning has become an essential functional module for multi satellite cooperation.In the multi satellite cooperative earth observation mission planning problem,the establishment of the problem model is the foundation and the solution of the model is the core.This paper focuses on the modeling and problem solving of this problem.The main research contents include:Based on the basic elements of multi satellite and multi task planning,the complex constraints of task planning are simplified into a general model through basic assumptions.The model is the basic model of multi satellite cooperative earth observation task planning,which can be applied to different types of scenarios by adding additional constraints.The constraint conditions of multi satellite and multi task collaborative planning problem model are complex,and specific constraints are added for specific scenarios.At the same time,the optimization objectives of the problem model are uncertain and need to be customized for specific needs.This paper designs a weighted optimization objective function based on the sum of total income value,total completion degree and total yaw angle.The optimization objective function can meet most of the basic optimization objectives of the demand by adjusting the weight of sub objectives,and reduce the uncertainty of the optimization objectives of the problem model to a certain extent.A solution method based on genetic algorithm and genetic tabu algorithm is applied,which considers the strong search efficiency of genetic algorithm and the strong local search ability of tabu search.It solves the large-scale combinatorial optimization problem in multi satellite and multi task planning,and overcomes the problems of large solution space and low solution efficiency.In the solution of genetic algorithm,the observable period of the satellite to the target is continuous,and the gene segment with the observation satellite and imaging time as the target is used to plan and solve the imaging time of the satellite observation target,to make it suitable for satellites with strong attitude maneuverability.Then,the combination of tournament and double defeat elimination system is used to design the selection operator,the tournament method is used to improve the selection efficiency,and then the double defeat elimination system is used to improve the survival rate of high fitness individuals.In genetic tabu algorithm,using the strong local search ability of tabu search,taking the optimization result of genetic algorithm as the initial solution,the neighborhood structure is designed based on the mutation idea of genetic algorithm,and the optimization result of genetic algorithm is locally optimized.The simulation results show that the two algorithms are feasible and effective to solve the multi satellite and multi task planning problem.Based on the general problem model and solution algorithm,this paper designs and develops a multi satellite collaborative earth observation task planning simulation system to realize the whole process visual simulation of multi satellite collaborative earth observation task planning.Based on the simulation system,the application scenarios of agile satellite and non-agile satellite,optical satellite and SAR satellite are established.The correctness and effectiveness of the model and solution algorithm are verified again through the simulation demonstration of the application scenario.