Design And Implementation Of Control Software For CNC System Of WEDM

The medium speed wire cut electrical discharge machining(WEDM-MS)is one kind of special processing machine with high processing precision and high cost per-formance.It is widely used in the processing of precision parts.Limited to the cost and the convenience of system development,most computer numerical control(CNC)systems of WEDM-MS made in China still apply Disk Operating System(DOS)at present.The calculation speed and control ability of DOS are strong,nevertheless,the user experience of DOS is poor.In order to enhance the competitiveness of the system,the interactive Windows system is gradually introduced into the industry.However,the control software in WEDM using Windows systems also has some inadequacies,such as imperfect software functions and unfriendly interface display.In order to complete the upgrading of the original operating system using DOS while maintaining the existing advantages,the redesign of the CNC system of the WEDM-MS in this thesis adopts the idea of modularization design,which means the system is divided into the upper computer and the lower computer according to the functions.The upper computer is responsible for human-machine interface as well as real-time visual control.The lower computer is responsible for real-time machining control,and performs precise interpolation and compensation calculation.The upper computer and the lower computer exchange real-time data through the dual-port RAM.The main work of this thesis is developing the control software for the upper computer using Windows XP Embedded system,designing and implementing the code prepro-cessing module and graphics drawing module of the control software based on the interaction between the user and the CNC system.The control software adopts Microsoft Foundation Class(MFC),and the func-tional design of the software fully considers the user requirements and the convenience of operation.Considering the different habits of users,the code preprocessing mod-ule supports a variety of code import and edit methods.Considering that the general codes for wire-cutting include 3B code and ISO code,the code preprocessing module supports the identification and verification of 3B code and ISO code,so that the versa-tility of the system can be improved.In order to unify the underlying development and comply with industrial development trend,the code preprocessing module implements the function of converting 3B code into ISO code.The graphic drawing module sup-ports static and dynamic graphic drawing,plane and stereo graphic drawing,as well as other drawing functions,which makes it convenient for users to observe processing process from different perspectives.The implementation of graphics drawing com-bines the methods of projection transformation and rotation transformation.Besides,the graph is scaled to make the features of the original graphic and processing track more complete when the graph is displayed on the screen.The modularized design of the CNC system makes the design and implementation of the control software in the upper computer relatively independent,and the software has strong versatility,which can be applied to all kinds of WEDM adopting modu-larization.The design of the control software for the CNC system fully analyzes the requirements when the user interacts with the CNC system.The realization of these function modules not only combines the functional characteristics of the machine tool,but also considers the convenience of operation and the aesthetics of the interface dis-play.It is a highly feasible solution for the control software.