Research On The Open NC Systems Based On PC

An open NC system, built on an open platform ,has the features of opening, interchanging, replanting, and expanding. The open NC system must have a modular structure, so that users can choose, integrate, change or expand the functions of the system depending on the requirements of different applications. The development of the research on the open NC system in the world has attacted much attention. However, the relative research in China is still at the exploration stage. In this thesis, some techniques about the design of the open NC system are studied, including the analysis of the open system, open design of the hardware structure, software modeling and developing, etc. In addition, the application of the open NC system was also investigated combined with the requirements of unit training teaching. The main work and results are as follows:1) On the basis of analysis of the development of modern NC system and the functional features of the open NC system, the guidance of detailed design of software for the open NC systems was given.2) The hardware structure of the system consists of a PC as the platform, step motors and their corresponding drivers, which forms a NC system. The system combined with a PC and NC hardwares, following the definition of the open standard PCI bus, has the features of opening, multi-module, economy, embed ability. The running precision and reliability of the system can be guaranteed. This method is suitable for building the medium or small NC system.3) Combining hardware configuration, the software structure and development method of an open NC system were studied in this thesis. On the basis of object-oriented method, the modular design method and the control strategy of interrupt mechanism are introduced in the software structure of the system. Every function is put into an independent module i.e., any change in one module have no influence on other module. The system can offer the corresponding programmer interface for users, which meets the different demands.4) In this thesis, an open NC system based on PC is designed. The NC system is based on PC and a motion control card, and works under Windows NT. Because of the use of the hierarchical structure and modular design, the CNC system has many advantages, such as friendly user interface, fully open kernel, easy operation, easy secondary development. Additionally, it is convenient to add end user's special secondary development. Additionally, it is convenient to add end user's special functions and supports third parties' software, and posseses network communication ability because it supports a lot of network protocols. Now the NC system is used in CAK6140VA machine tools to take place of the old system of GSK928TA. It can run in standalone environment and network manufacturing system based on DCOM technology. The experiments show that the satisfactory result was achieved for teaching of the students in higher vocational schools.