Research Methods Of Complex System

The subsystems of various kinds of complex systems are numerous and have hierarchical structure. The relation between them is complex. There is exchange of energy, information and material with the external world constantly. Utilizing operation research, logic mathematics, discrete mathematics, fuzzy mathematics, statistics mathematics, computer science, systems science and artificial intelligence, to study most high-level complex system of system science has become more and more attention of scientific workers of control science and system science.With high-speed development of space technology, information technology and industrial manufacturing technology, the control theory is required to deal with the more complex problems of control of system, and offer more effective control strategy to them. Generally speaking, the characteristics of the complex system are on the whole structure, shown as being non-linear, uncertainty, infinite dimension, distributed and multi- hierarchy, etc.; shown as the uncertainty, randomness and incompleteness of the signal, the mixing of the picture and symbol information, etc. in the information dealt with; shown as the mixing of mathematical operation and logic operation in calculating. It is obvious that the complex system is not only different from the routine in identification, analysis, design, realization, etc., but also is different from modeling which is more important. Based on hierarchical structure of the complex system, according to multi-disciplinary knowledge, by the qualitative analysis of causality of numerous variables and feedback mechanism of the complex system, systematic dynamics emulation model is set up. Then, according to the difference between the actual conditions and every subsystem, existing system engineering means is employed respectively, establishing the emulation model with qualitative knowledge and the judgement and quantitative model technology, and laying foundation for utilizing technology of the computer, knowledge engineering and relevant experience knowledge in the future, and for establishing expert system and understanding, analysing, describing, predicting, policy-making and research of control function.