Study On Multi-objective Optimization Of Multi-satellite-station TT&C Scheduling

Multi-Satellite-Station TT&C (telemetry tracking and command) Scheduling (MSSTS) technology is the effective way to solve the conflict between the limited TT&C resources and the increasing satellite TT&C requirements. MSSTS is a multi-objective combinatorial optimization problem. This dissertation studies the multi-objective optimization strategy of the MSSTS. The main results achieved in this dissertation are summarized as follows.The MSSTS model with multiple objectives is developed. According to TT&C element, process and the analysis of the satellite orbit coverage, the schedule constraints considering the available TT&C arcs conflicts and the equipment transition time are presented.; according to the TT&C requirement and TT&C rule, the four objective functions, including the length of TT&C arcs, the satellite TT&C priority, the ground station use priority and the ground station- TT&C network efficiency, are developed; using the available TT&C arcs as design variables, the MSSTS model with multiple objectives is finally presented.The classical multi-objective optimization strategy for the MSSRS problem is studied. 1) Multi-objective functions are turned to single-objective function by weighting method. According to the characteristics of MSSTS problem, which conflicts are many and it is feasible solutions are few, a genetic algorithm with non-feasible solution repairing strategy is proposed,which effectiveness is verified by Exhaustive Attack Method (EAM), and it is dependability is verified by many simulations. 2) The four objectives are firstly sorted on basis of objectives stratification, and then the MSSTS problem is divided into four single-objective problems and optimized patulously by the proposed GA according to the objective order. The results obtained are compared with the results with the opposite objective order, and the characteristic that the obtained schedule is greatedly affected by the objective order is demonstrated.The evolutionary multi-objective optimization strategy for the MSSTS problem is studied. 1) The MSSTS optimization model using the multi-objective evolutionary algorithm is firstly developed, and its Pareto fronts are successfully obtained by the NSGA-II. 2) The objective values and the number of available TT&C arcs acquired by different methods such as the weighting method, the objectives stratification and the NSGA-II are compared with each other. The schedule strategies obtained by different methods are also compared by gantt chart. The results show that the optimization strategy using the NSGA-II has the best performance.The Satellite TT&C Managing Software is developed. The modules of the software integrated common basis subsystem and the MSSTS subsystem are designed, and the relationship of data information among these modules is established, and then the Satellite TT&C Managing Software is developed, which integrates the satellite orbit simulation function, the ground station TT&C coverage analysis function and MSSTS function.Based on the worldwide development of MSSTS technology, the MSSTS model with multiple objectives is established, and the classical multi-objective optimization strategy and the evolutionary multi-objective optimization strategy for the MSSRS problem are respectively studied, and then the Satellite TT&C Managing Software is developed. The study is significant and valuable for both theoretics and practice, which can provide MSSRS strategy for TT&C department.