The Research Of Double NURBS Optimization For Five-axis Tool Ptah

High speed and high precision CNC processing is main development trend of themodern NC machine tool, and is an important sign of the development level in theequipment manufacturing industry of a country. In order to realize high speed and highprecision CNC processing, it mainly depends on three aspects, that is, the path, motioncontrol and mechanical structure. Therefore a good processing path is foundation toachieve high-end CNC processing. At present NC path is designed by the CAD/CAMsoftware, and when the processing path can’t satisfy the requirements of the processing,then the path optimization is a good kind of solution.In this thesis, the basic principle of five-axis tool path is introduced at frist,expounding the advantage of fine-axis tool path described by double NURBS curve,and pointing out that it is necessary for double NURBS fitting. This thesis brieflyintroduces the basic algorithm process of NURBS fitting, focusing on the analysis ofthe defects of the existing NURBS fitting, and put forward the regional optimizationalgorithm based on the characteristics of points, realize piecewise NURBS curve fitting.In this thesis, the main research object is five-axis tool path optimization, introducesthe double NURBS curve fitting process of cutter center point and cutter orientationvector in detail, and analyses the smoothness of path after optimization and thereduction of nonlinear error and so on. At the same time, the thesis points out that thereare some problems for using the same node vector for cutter orientation vector fittingonly, and puts forward corresponding methods to solve, and has obtained the goodeffect.Finally, the thesis introduces the optimization software the project completedbriefly, and verifies the effectiveness of the double NURBS optimization methodthrough an example, also points out the deficiency of the subject research and putsforward outlook of five axis tool path optimization.