Technologies Of Areas Segmentation And Machine Tool Error Compensation In The Processing Of Complex Curved Surfaces

As the core components of the high-end equipments, the complex curved surface parts have a direct impact on the performance of the high-end equipments. With the rapid development of the high-tech industry in China, the demand of complex curved surface parts is increasing rapidly. Our country is facing a great challenge in the manufacturing of the complex curved surfaces. A complex curved surface part usually contains a variety of surface types. It is hard to acquire a high-quality and high-efficiency machining with single machining parameters. The machining efficiency of the parts can be improved by surface segmentation and using different processing parameters. The geometric errors of the machine tool also have a huge impact on the precision in the processing of complex curved surface parts. Therefore, it is an effective way to improve the processing in both efficiency and accuracy by studying the processing areas segmentation and machine tool errors compensation.Firstly, the format specification of general data interface IGES is analyzed. Based on the elements of trimmed surface in IGES, the complex curved surface model is disintegrated into surface patches. And then, by using the definition of feature size for a curved surface patch, the classification is achieved and the rough segmentation is accomplished. Based on the surface curvatures, the curved surface is divided with processing significance, achieving the subdivision. After the subdivision, different processing areas are processed with different parameters and the processing efficiency of the complex curved surface can be effectively increased.While the processing efficiency is increased, the processing accuracy should be improved as much as possible to guarantee the function of the complex curved surface parts in high-end equipments. The geometric error of the machine tool accounted for a large proportion of the total machining error. This paper will research in the methods of error measurement and compensation based on the DMU70V five-axis machine tool. Firstly, the basic structure of the machine tools is analyzed, and the commonly used measuring methods of spatial geometric error are compared. Then, the error identification of nine-line method is discussed. And a comprehensive error measurement on translation axes is taken by using dual-frequency laser interferometer. The positioning of rotational axis B is researched and an auxiliary fixture is designed to complete the measurement of rotational positioning error. After motion coordinates of the machine tool are properly arranged, the motion model of the machine tool is established. Based on translation motion model and rotating angle changes, the compensation points are acquired with steepest descent algorithm. And finally, the compensation codes are outputted and the compensation is verified by the simulation.Based on the OCC kernel and MFC framework, the machining auxiliary software with above-mentioned functions is developed. At the same time, in order to obtain better processing quality, the processing optimization module is developed to realize the smoothing of tool vectors and to avoid interference with the non-cutting areas. Quality evaluation module is also designed, so as to evaluate the precision of the processed workpiece. Taking the designed model as processing target, combined with the auxiliary software, the processing experiments are carried out. It is proved that after the segmentation the machining efficiency is increased, and after compensation the machining accuracy is substantially improved.