Research On Complex Curved Surface Machining On The Open Architecture Controller

With the development of computer technology and microelectronictechnique, reconfigurable and modules for the NC system become the development trend.open architecture controller may satisfy these needs, thus they have become the studying focus in the field of manufacturing technology since the 90s of the last century.The open architecture controller with curved surface machining capability has been developed.It follows OMAC API protocol, satisfy with the need of open architecture controller.Research of complex curved surface machined on the platform has been done.The main research as follows:International standard is one of the most important factors for the implement of open architecture controller.By making comparison between three international standards, the OMAC standard is proposed to implement the open architecture controller in this dissertation. Intercommunion between inner modules and that between system and external is implemented by corresponding standard interfaces.The modules developed between different suppliers can coordinate together so as to satisfy the requirement of open system such as interchangeability, expandability, portability and so on.Basic interface has been defined and the main modules of the system has been analyzed based on UML.It has made the system implemention visualization and debugging easily.The implementation techniques for the open architecture controller are researched in this dissertation, which are COM module technique and FSM technique. Due to the COM module technique is proposed, the modules can be reused with binary codes.After all the modules are developed, the entirely system is assembled with them so as to improve interchangeability, expandability, portability for the system.Furthermore, the behaviors of the machine tool are moduled with FSM to separate the controller and mechanical part.The controller can be changed independent so as to improve the openness of the system for the control programs depended on the particular machine tool are limited locally.In the process of curved surface machining, that whether the path planning algorithm is excellent or not affects directly the workpiece in both precision and efficiency.The maximal space isoparametric curve algorithm is proposed in this dissertation, which can remarkably reduce path redundancy so as to improve the efficiency of the curved surface machining.Interpolation function is the kernel for CNC system.In connection with the defect that the interpolation error based on the cutter positon points is larger than the interpolation algorithm based on the cutter contact points proposed in this dissertation.It can automatically adjust the federate according to the curvature radius so as to limit the error in range permission to ensure the machining precision of the curve.Furthermore, in respect of algorithm implementation, the simplify algorithm of NURBS base functions and their derived numbers is proposed to improve the real-time capability of the system.Cutter compensation is one of the important functions for the current CNC. The implementation of the cutter radius compensation and length Compensation is researched for the curve surface machining based on 5-axis milling machine tool.The compensation algorithm convenients the programme of curved surface machining and it need not modify the NC programme due to cutter changeable or cutter wear.Finally, the 5-axis milling machine equipped with the open architecture is completed.It has the features of openness such as interchangeability, expandability and so on.Machining simulation is carried out based on VERICUT software for the curved surface machining, and prove that it has function of machining complx curved surface.Also,experiment has been designed for the NURBS interpolation algorithm based on the HCNC open platform.The result has proved that the algorithm can satify the requirement of NURBS curve machining with high speedrate and high precision.