The Design Of Full Software CNC System Based On The Method Of Rotary Contour Surface

A rotary contour processing method is a new processing method of contact line for space surface.It can effectively reduce the tool path,so that the machine affects the surface quality of workpieces in NC machining has been reduced,improves machining efficiency.Only the NC system is the curve interpolation and no surface interpolation,therefore must be compiled with full software CNC system complete surface interpolation program.So as to make the structure of CNC system was simplified and the system has better flexibility,laid the foundation for the open CNC system can have a better future.In order to solve the problem of complex curved surface processing,the hardware of CNC system software circuit designed is mainly composed of X86 PC architecture and standard I/O interface circuit,software platform with open source code and good portability of the Linux operating system.In order to improve the machining efficiency,the author uses the method of contour surface approximation to plan the cutter position of the convex non straight surface.In order to solve the problem of real-time interpolation,the author propose a real-time interrupt method of non threaded processing,common interrupt using priority different kernel thread processing,so as to achieve the improvement of the interrupt execution mechanism.The author propose a fast DDA interpolation algorithm,it adopts the method of integral accumulator overflow value,the DDA interpolation method in the linear and circular interpolation process significantly reduced the number of times for longer periods completed the highest interpolation interpolation cycle to achieve shorter feed speed,so that the real-time problem of compound interpolation has beento solve.The system interface is designed by Qt,which can realize the basic functions such as the selection of the working mode,the display of the graphic processing,the display of the state interface,and the control of the switch button.After the improvement of Linux interrupt execution mechanism,the theoretical analysis can solve the problem of interrupt delay and task processing time,and finally meet the real-time requirements of CNC system.The improved DDA interpolation algorithm is verified by an example.The results show that the number of interpolation is reduced,the interpolation cycle is shortened,and the real-time performance of the CNC system is improved.