Studies On Architecture Of Decentralized System In Intelligent Building

In modern years, buildings, especially large-scale public buildings, have configured huge sensor networks and the automatic control system with the help of deeply penetrating of IT and Internet technology in the field of engineering application, and development of electronic processing and manufacturing technology. The trend that architecture becomes more intelligent and information could not be halted. However, those intelligent buildings usually don not operate so "smart". Actually most of the automatic c ontrol systems are even half paralyzed, only provide remote monitoring function. While centralized system architecture is the key reason that caused engineering application bottlenecks during the whole period including automation system design, function design, on-site configuration and networking, operation and modification difficulties. Furthermore, centralized system cannot finely meet the swelling needs of information management and various functions in intelligent building in the near future. Therefore, a new and entirely different system with decentralized architecture has been developed by Building Energy Research Center in Tsinghua University. This new system can serve automation operation, optimization control and intelligent management in modern bu ildings comprehensively, and solve the existed engineering and application problems in intelligent building field fundamentally.This paper provides a theoretical analysis of decentralized building information system. Researches involve basic elements desi gn, system architecture design, basic functions design, operation mode and feasibility, stability and effectiveness of the system. Work mainly includes three aspects:First, a new global model of building construction and all kinds of mechanical and electrical system is developed in the decentralized view angle. The whole building and mechanical systems are combined by two basic elements: space unit and equipment unit. These basic elements are described by standard databases including all kinds of local inf ormation. Network and sub-networks constructed by basic elements can stand for building space and mechanical systems. Intelligent node and network definitions, and topology features are discussed in this aspect.Second, a general computation model of build ing operation tasks is developed in the decentralized view angle. Building operation tasks can be divided into four categories of basic problems(functions) that are the Diffusion Problem, Summation Problem, Distribution Problem, and Single Point Problem, which involve system monitoring, mechanical and electrical optimization control, fault diagnosis, human management and operation, and so on. Every category of basic problems has certain network model and solving method for several building service applications. This paper gives standard definitions for each kind of problems, and provides many cases to explain them. Meanwhile classification and definition of basic problems and their popular solutions support the computation and software operation architectur e of decentralized system.Third, a mathematical model of decentralized building information system is established. The concepts of intelligent node, network, basic problems, and network modelling and computing are defined standardly and mathematically. Based on this mathematical model, general computing methods and relative properties are analyzed deeply. Thus we proof the feasibility, stability and effectiveness of the system in actual operation via algorithm, convergent and efficient analyses.