Development For Open CNC Teaching Platform

The open CNC has many advantages compared with the traditional numericalcontrol system, and become the direction of future numerical control technology. On theone hand, for improving the teaching of NC technology and students’ practical ability,on the other hand, help the student to study the open CNC system on the world and get abetter understanding of the open CNC, in this paper, a kind of open CNC platform basedon motion control card was developed.Firstly, this paper analyzes the three typical open CNC structure and determine thebasic structure of this platform, on the base of “PC+motion control card” structure,design the hardware system, distribute the task of PC and PC+motion control card, bythe design of electrical schematic and selection of specific hardware, finished themachine and control cabinet.The development of software control system of this platform is the next task. Afterthe determination of the development tool and modular programming method,determine all function of this platform and divide the system into four modules, they aretask generation module, human-machine interface module, simulation module and axisgroup module. The task generation module is the key of this software system and is themost complicated module. This module used for the automatic mode and MDI mode.This paper will use compiled decoding way, and give the standard format of the NCcode. Subsequently, the paper introduced the two important steps: informationextraction and depth convention of current line code. The former complete theinformation extraction and storage of the information, the latter finished the depthconvention with the coordinate system and system parameters, lastly, generate the seriesof execution steps which contain movement information and auxiliary controlinformation. This system has improved diagnostic function, the diagnosis along with theimplementation of the entire task generation module, the paper gives detailed diagnosticmethods and error handling process. Finally, this paper developed the palne toolcompensation function module, gives a detailed tool compensation methods andprocesses. In addition, this paper developed the human-machine interface module,simulation module and axis group module.Finally, by processing wax, test the function of the platform, such as toolcompensation function and simulation function.