Research On Integrated Modeling And Simulation Methods For Effectiveness Optimization Of Complex Multi-Satellite Systems

With the coming of information era, it is of great significance for society development and nation security to construct integrated space information acquisition system, which will operate in intelligent, distributed, collaborative, autonomous, multi-satellite mode. How to analyze, evaluate and optimize the integrated effectiveness of the complex systems to get the most satisfying one is a crucial problem which must be answered as early as possible.We made a detailed analysis and concluded that only if a general system analysis and optimization framework were adopted can we solve the multitudinous complex problems. The Evolutionary Computation (EC) based optimization methods, adopting self-adaptive stochastic searching technology for global optimization, possess comprehensive adaptability and compatibility, moreover, the Multi-Agent Based Modeling and Simulation (MABMS) methods are competent for analyzing the integrated effectiveness of complex intelligent systems. So, we presented an EC based simulation optimization design framework for Multi-Satellite Systems (MSSs). Under the framework, emphasizing on earth observation MSSs, we have done some research mainly to propose effective methods for system effectiveness analysis, establish Measures of Effectiveness (MoEs) and their solving models, set forth integrated Modeling and Simulation (M&S) methods, and construct corresponding M&S software environment.First, we investigated the various complexity characteristics existing in MSSs in detail, analyzed and induced typical composing configuration of MSSs, explored their distribution and collaboration relationships from the aspects of space, time, physics and function, and analyzed the overall functions, main characteristics, implementation mechanisms and organization structures of MSSs operating in the intelligent, autonomous, collaborative mode.Then, we reviewed briefly several main general methods for effectiveness analysis, and put forward the overall framework of effectiveness analysis methods based on M&S. According to the framework, we defined the hiberarchy of MSSs, discussed how to analyze the effectiveness of the subsystems in System of Systems and gave two basic methods: mission requirements decomposing and effectiveness sensitivity analysis of holistic system, set forth the four-element group of MoEs for information acquisition: Content, Area, Quality, Response time, and concretized them into corresponding MoEs in four-dimension space (Space, Spectrum, Energy, Time, SSET for short) of information acquisition by remote sensing.And then, we put forward an information grid model in discrete SSET space, deduced the models for computing total information capability of one single remote sensor, analyzed the information capability of MSSs in respective dimension of the SSET space, and set forth the following concepts: physical coverage, effective coverage, sufficient information quantity.Through a typical example, we provided simulation based approaches and models to solve the MoEs for the system in detail. In order to search the points in or on the edge of the irregular coverage regions, we designed and implemented several general algorithms and named them throwing a stone into a pond, igniting an oiled hoop, absorbing step by step. The main ideas and contents of them are expounded.By analyzing the characteristics of the models and integrated computing for reliability of complex large systems, we set forth a new model named Composite Logic Tree Model (CLTM) and its modeling principles, and designed a recursive algorithm based on CLTM, and developed the corresponding software. The design ideas, architecture and main functions, implementation mechanisms of the software are introduced.And then, we pointed that, the models built for holistic system optimization should be integrated multidisciplinary isomorphic Hybrid Heterogeneous Hierarchical Models (HHHMs) in the description level of decomposing structure. By analyzing the supporting mechanisms and limits of the Object-Oriented M&S (OOMS) methodology, and the excellent characteristics of the MABMS methodology, we presented the Multi-Agent/Object (MAO) based M&S and optimization method framework for complex MSSs. Then, we discussed the mechanisms of Agent/Object co-existence, the principles of choosing the granularity of the Agents/Objects and defining their attributes and behaviors, the requirements to integrated system modeling by EC based Multidisciplinary Design Optimization (MDO), and presented the methods of Agent/Object oriented structure decomposition and re-construction, constructed class diagrams of objects in MSSs, set forth the rules for hierarchical entity decomposition and aggregation. Taking example for satellites, we presented their various Agent models. At last, the main organization models of Multi-Agent Systems (MAS) in MSSs are presented.Adopting above ideas, methods and models, we have designed and implemented the Modeling and Simulation Software for Integrated Effectiveness of Multi-Satellite Systems (MSSE for short). With powerful visualization and interactive capabilities, it can be used to build HHHMs of complex MSSs, configure the missions flexibly, monitor the whole simulation process, present all-around reports of data analysis and display vivid 2-D and 3-D animations, and eventually provide powerful supports for the design, evaluation and optimization of the MSSs. Finally, the design concepts, architecture, functions, and implementation mechanisms of the software are expounded.