Research On DFD Based C~4ISR System Function Designing Method

As C~4ISR system is widely used in military area, its requirement for function is increasingly increased. Function is an important element of system and its performance basis, its design quality is directly related to the quality of the system and whether the system can accomplish its target. How to realize a better function and its verification will be an important way to improve the quality of C~4ISR system.At present, there are a few problems in system function design and verifying. Firstly, it is lack of principles and foundation for system design. Secondly, current design tools can't support verification. Thirdly, it is lack of verifying theory and verifying tools. To solve the problems, base on the theory of data consistency, bring forward the method of generating system function model directly from operational view product data, therefore avoiding randomicity of manual design and intensifying data consistency of architecture. Expand modeling element of data flow diagram, therefore enabling the model can describe the logical relationship between data flow and provide the basis for transforming to executable model. Based on the system function model, the generating method of system function executable model is studied. To be exact, the following work is done:1. The relationships between system function description product and other architecture product are analyzed.Based on the introduction of system function product, the relationships between system function description product and other architecture products are firstly analyzed, these products include OV-2, OV-5, SV-1, SV-5, SV-6,SV-7, SV-10 and so on. Analyzing the relationships between system function product and the OV products is used for system function modeling and the others are for generating executable model.2. The system function modeling method is studied.Based on the analysis of relationships between system function product and OV products, how to generate system function description model from OV products especially OV-5 product is studied and the principles of choosing function from operational activity are provided, and then the rules of building logic relationships between function are brought forward, therefore provide the system function hierarchy model.3. The system function modeling tool is realized.According to the need of system function modeling, the modeling tool is split to two child tool, respectively describe the hierarchy and the data flows between functions. Data analysis function is added to the former system function modeling tool, through which system function hierarchy model can be realized automatically by analyzing the OV products data. The three logical signal"AND","OR"and"XOR"are added, which can express the logical relationship between data flows.4 The method of generating system function executable model is studied.Based on the analysis of relationships between system function product and SV products and system function description model, the Petri net based executable model frame is made, and then integrate other SV products data especially SV-1, SV-6, SV-7, and SV-10 to supply content for the frame.5. The model transfering tool is realized.Based on the analysis and the transferring rules, first modularize the transferring tool, and then provide XML as the middle product between the modeling tool and transferring tool, therefore providing a unified tool among architecture modeling tools.Lastly, based on the study for the theory methods, some kind of field operations aerial defenses C~4ISR system is taken as an example to illustrate the methods that studied in this paper. The OV products model are described first, and then build the system function description model based on the rules and principles brought forward in this paper. And then the model is transferred to Petri net based executable model, through which the verification of system function is realized.