Abstract : This paper presents an open CNC system for parallel machine tools, built using a PC + adapter as the hardware platform and Windows operating system as the software platform. The research focuses on the overall scheme of the CNC system, hardware platform construction technology, multi-task real-time scheduling strategy, user interface design technology, and parallel machine tool simulation technology. The CNC system software was developed according to software engineering principles. Keywords : parallel machine tool; open structure; CNC system; CAD/CAMr. To improve adaptability to the production environment and meet rapidly changing market demands, the global machine tool manufacturing industry has been actively exploring and developing new multifunctional manufacturing equipment and systems in recent years. Among the breakthroughs in structural technology, the parallel machine tool, which emerged in the 1990s, is a CNC machine tool that uses a parallel mechanism as the feed transmission mechanism. Functionally, it integrates multiple processes such as machining, measurement, assembly, and material handling. Performance-wise, it integrates high rigidity, high precision, high speed, high flexibility, light weight, and low cost, making it a mechatronic product. Therefore, after Giddings & Lewis and Ingersoll in the United States successfully developed the first parallel CNC machine tools called "VARIAX" and "Hexapods" in 1994, the academic community at home and abroad launched various product prototypes with different structures. my country also included the research and development of parallel machine tools in the national "Ninth Five-Year Plan" and "863" high-tech development plan, in order to develop its own parallel machine tool products before foreign products occupied the Chinese market. Tianjin University, with the support of the Tianjin Municipal Key Fund and the Ministry of Education's "211" Project, carried out research on the design theory and key technologies of new multi-functional parallel machine tools and the construction of prototypes. [b]1 Machine Tool Control Principles 1.1 Machine Tool Transmission Principles[/b] Figure 1 shows a schematic diagram of the equivalent mechanism of the machine tool. The main feed mechanism of the 3HSS parallel machine tool (where H is a helical pair and s is a spherical pair) adopts a three-degree-of-freedom parallel mechanism, consisting of a moving platform and three pairs of column saddles as a branch. Each branch contains three parallel fixed-length rods, one end of which is connected to the saddle and the other end to the moving platform via ball joints (or Hooke joints). The saddles are driven by servo motors and ball screw nut pairs, moving up and down along rolling guides mounted on the columns. This allows the moving platform to provide translational motion in only three directions along the Cartesian system. It can be seen that the essential difference between parallel machine tools and traditional machine tools is that the movement of the tool in the operating space is a linear servo motion in the joint space. Nonlinear mapping is problematic because current CNC system trajectory control algorithms are developed for Cartesian coordinates and cannot be directly used for motion control of servo drives in parallel machine tools. A commonly used and readily applicable trajectory control algorithm for parallel machine tools involves first discretizing the tool trajectory in the operating space according to accuracy requirements, then performing coarse interpolation on the discrete points along the time axis based on the interpolation sampling frequency provided by the hardware. The data is then transformed into joint space through virtual-real transformation before being sent to the controller for fine interpolation. Therefore, the hardware platform construction of a parallel machine tool CNC system must rely on an open CNC system architecture, while the software design primarily addresses the efficiency and speed transition issues of the controller's virtual-real mapping interpolation algorithm. [b][align=center]For more details, please click: Construction of a Parallel Machine Tool CNC System Based on an Open Architecture[/align][/b]