The Research About History Database In Process Industry

With the development of modern process industry, manufacture enterprise is larger and larger and the production technology also becomes more and more complicated. So we need to monitor the whole production process and supervise these discrete instruments and controllers in centralized way. Upon that, SCADA (Supervisory Control And Data Acquisition) was produced. It generally includes data acquisition and control information transfer, historical data recording and trend display, warning recording and event processing, report generation and printing. Among these, it is very important to store and query the historical data, which is mainly used to improve the technology process, device performance maintenance and trouble diagnoses.There are more attentions on history database production after year 2000 and some famous overseas company developed their own one. So it will be valuable to develop an open architecture of history database, improve the storing and querying process and the compression algorithm of historical data. The research is also useful to break the foreign technical barrier. The research can be outlined as following:1. Based on the analysis of actuality and development trend of the process industry and SCADA software, this paper suggests an architecture and frame of history database, which aims at the lack of special research. Furthermore, integrated with the distribute control system of SunyTDC9200, this paper has implemented a set of history database named SunyHDB, which has taken the component technology of ActiveX. This technology makes the system easily used and had good transplantation performance.2. According to the analysis of engineering database system, this paper argued that the special history database system was more suitable than the traditional commercial relational database in process industry. This paper also introduced two productions of history database.3. This paper summarized the characters of historical data in process industry and defined the models of signal tag, process data and history database property.4. Two optional storage methods, which included memory storage and disk storage, were presented to satisfy with the access demand of APC (Advance process control) software. The research made emphases on improving the storage and querying way and mending the traditional structure of time information. It has also brought forward an integrated file management system and the data management ways of multiple index and hash link-table. Furthermore, it analyzed the querying efficiency of historical data in theory.5. Three ways was presented to save the disk space, such as timing storage and dead band compression tactic, archive of data file and swinging door compression tactic. Based on the analysis of swinging door compression algorithm, this paper compared two realization tactics and gave the detail information. The three ways have been proved wonderful to reduce the amount of data.