Research And Development Of Five-coordinate Linkage Open CNC System Based On LinuxCNC

With the development of user’s demand for CNC system towards personalization and customization,the mature closed CNC system on the market is lack of openness and flexibility.In addition,most of the high-quality CNC systems are still in the hands of some western developed countries which have friction with China recently.The dependence of the market on the closed numerical control system abroad not only limits the individualization of the numerical control system,but also is not conducive to the long-term and stable development of the manufacturing industry in our country.In order to meet the requirements of openness and flexibility of machine tools for CNC system,and to reduce the dependence on products with property rights in other countries,this paper develops a five-coordinate linkage open CNC system based on LinuxCNC,and designs and builds a micro horizontal five-coordinate linkage experimental prototype.The function of numerical control system is verified on this experimental prototype.The main contents are summarized as follows:First of all,through a large number of literature research,this paper summarizes the research status of open CNC system based on LinuxCNC at home and abroad,and determines the functions that need to be developed on LinuxCNC.A micro five-coordinate machine tool is designed and built as the experimental prototype,and the function developed in this paper is verified based on the experimental prototype.For the research of LinuxCNC,this paper analyzes the source code in combination with the relevant documents.Firstly,the overall architecture is analyzed,and then the RCS/NML communication mechanism and the working process of motion controller are analysed in the level of source code.The flow of LinuxCNC trajectory planning and interpolation calculation,as well as the execution process of motion control command are analyzed in detail.Finally,the points for attention in the use of LinuxCNC and the configuration methods of key files are summarized.Aiming at the development of five-coordinate linkage open CNC system based on LinuxCNC,this paper analyzes three common ways of developing CNC system based on LinuxCNC,and uses these three ways to enhance and expand the three functions.Using HAL component development method,on the basis of completing the five-axis kinematic analysis,the related kinematic modules are written to realize the five-coordinate linkage machining function of the open CNC system.Using the way of optimizing the source code to realize the enhancement of the original ladder speed control algorithm.The preliminary implementation of the precision control system proposed in this paper is completed by using the program that works with LinuxCNC.Aiming at the design of the micro five-coordinate linkage experimental prototype,this paper first determines the horizontal machine tool with low center of gravity and easy chip removal.Then the horizontal five-coordinate linkage machine tools with different structures are compared and analyzed,and their overall layout is determined.The structure and selection of key components are determined by theoretical calculation and simulation analysis.After the parts machining and the whole machine assembly are completed,the positioning accuracy and repeated positioning accuracy of the machine tool are tested according to the national testing standard,and the test results are analyzed and processed.Finally,this paper carries on the example verification of the open CNC system,completes the machining test and the precision control test by using the micro horizontal five-coordinate linkage experimental prototype,and summarizes the test results,analyzes the achievements and shortcomings in the research and development of the five-coordinate linkage open CNC system,and puts forward some concrete suggestions for improvement and improvement,which provides the basis for further in-depth research.