Research On Error Compensation Based-on Reconstruction Of Nc Program

With the development of science and progress of manufacturing industry, there is a growing demand toward precision machining. The accuracy of CNC machine tools is an important factor affecting machining accuracy, therefore, it has become a pressing matter to improve the accuracy of machine tools. There are two ways to improve the accuracy of CNC machine tools. Except for improving the machining accuracy and assembly accuracy of the machine parts to realize error prevention, error compensation can be used to improve the accuracy of the NC machine. Because of the relatively high cost and difficulty of error prevention, it is now gradually being replaced by error compensation. At present, error compensation technology has become the domestic and foreign scholar's popular research.The type of error compensation can be divided into software compensation and hardware compensation. As hardware compensation method has many defects, software compensation method costs lower and it is easier to realize, software compensation method has gradually replaced the traditional hardware compensation. This thesis adopted the software compensation. Machine tool error models and error data were used to reconstruct the ideal NC program with the intention to reduce the mismachining tolerance. The main content in this thesis is as follows:According to the method and purpose of the NC program reconstruction, the functional requirements of the error compensation software system based on NC program reconstruction were analyzed. Functional structure design of the system and planning of the module of system workflow were done. System– module– sub-module approach were adopted in the various sub-module design of the system.According to the requirements of NC program reconstruction, NC program modification algorithm and determination of the error compensation point were studied. Using the characteristics of the spatial orientation movement, linear interpolation movement and the circular interpolation movement of CNC machine tools, three Interpolation Algorithms for NC program modification were obtained.Through research and analysis, on the platform of Windows, an error compensation system based on NC program reconstruction was developed with VC++. Through the error compensation system, the ideal NC program was modified to realize NC program reconstruction. Through the simulation of ideal tool path and tool path before and after compensation, the correctness of the algorithm for NC program modification was verified. The reliability of software error compensation was verified through experiments. Experiments showed reconstructed NC program could effectively reduce the error of CNC machine tools.