Develop Of Control Software For SOFT CNC System

The industry and national economy of developed country is based on the mechanical manufacturing. The mechanical manufacturing is based on the computer numerical control machine (NC). NC is the result of information technology and traditional machine and it is the base of advanced manufacturing. In order to meet the request of modern manufacturing user, the structure of CNC is making great change. The open architecture CNC is substituting traditional CNC by degrees for its distinct excellence. Through contrasting the three main kind system model of open architecture that are OMAC (American), OSACA (European) and OSEC (Japanese), you can find than the first two are perfect and revolutionary, which aim at becoming common international standard of automation fields. They can afford all-sided open for all of the automation fields. But it means that the technical and non-technical matter, which is needed to think, is large amount. And the workload of developing is largeness, thus it's very difficult to apply to most OS in a short period. Whereas the OSEC model's object is to found an international standard for automatic control instruments in manufactory. Its goal focus on CNC and distributed control system, so it can realize step by step and afford direct direction .The SOFT CNC system adopts the OSEC model advanced based on the model of "universal PC + connecting board". The PC takes on not only system's management, which is non-real-time mission, but also real-time missions including real-time interpolation, position controlling, system state inspecting and machining state simulating. The connecting board takes on the responsibility to connect PC port and CNC machine drive. This model gives user much agility. It makes great use of PC's software and hardware resource, and the cost is low. Thus the SOFT CNC is suit of future advanced manufacturing technique's requirement.There are seven chapters in this thesis.Chapter one discusses the position, development of NC system in industry. Presents the definition, system structure and design model of Open CNC system. Points out main contents of the study. Chapter two to chapter five is the key and core of this thesis. Chapter two analyses the system's demand. Builds system structure model and establishes soft chip model. Chapter three discusses the developing environment and developing method choosing, software structure building, data stream analyzing, soft chips of machining code translating and track drawing designing. Chapter four discusses around real-time mission's actualization, which introduces the basal deal strategy of real-time mission and the method of using multi-thread technique to solve the real-time request in CNC system. Chapter five discusses NC's interpolation. First describes extended DDA arithmetic and this arithmetic in this SOFT CNC system's realization. Finally, describes the interpolation algorithm of third-order B-spline curve. Chapter six introduces the CNC software's function components and system's workflow. The testing and the error of the interpolator data analysis are described. In the end, the realization degree of open architecture in this SOFT CNC system is pointed out. Chapter seven summarizes the results of this research and indicates the direction to continue this study.