Design And Development Of Distributed Control System Based On CORBA

With the development of information technology and industry automation, a lot of control systems are applied to the process of manufacture. Many information systems, especially the ERP systems are also widely used in the enterprise. However, most of the systems focuse on the special function, and they are developed by different manufacture using different programming language and operation systems. These systems bring the economic efficiency to the enterprises; however, they also have brought a lot of questions. They usually can’t communicate with echo other. Especially, the problem in the communication between on-site supervision systems and upper layer information system hinders the development of information systems. In this paper, a solution based on CORBA and XML is introduced. The system can integrate the different kinds of monitoring systems and connect them with the upper layer information systems.In the scheme discussed in this paper, middleware is adopted to intergrate the existing SCADA systems. The overall system provides a logical view of data, while actual data still exists in the existing systems. We build some data wrappers which share the same interface with the API of the existing systems. Meanwhile, considering the integration with ERP and other upper layer systems, we build a global data integration layer to provide higher efficiency and usability. This integration layer accepts requests from outer systems and changes them to local requests. Then, this layer excutes the requests using the function of local wrappers and return the results to the callers. In this layer, thread pool and some other technology are adopted to provide higher efficency, usability and security.The features of the system discussed in this paper include instantaneity, across-platform, expandability, etc. In this system, the CORBA middleware is used as a software bus which is portable across platforms. Otherwise, XML is used as the data format between different systems. In this paper, we discuss the function, procedure and realization of every part in detail. There are further details that how to use multithreading and the thread pool technology on a cross platform environment.The system implemented in this thesis has passed the test and can satisfy the requirement of most monitoring systems. We also describe the the installation and usage of this systems. In the end of the thesis, the across-platform and expandability of this system is discussed. The solution in this paper can be taken as an example to imply the integration of on-site supervision systems and upper layer information system.