The Research And Development Of Open Architecture CNC System Based On PMAC

With the rapid development of NC technology,traditional closed architecture CNC system has been difficult to adapt to current manufacturing market environment and cannot meet the requirements of automation and information technology.Many countries are concentrating on the research on open architecture CNC system.Because of the late start in this aspect,our country is still in the role of pursuers.According to the theme of open architecture CNC system,this paper takes the Turbo PMAC 2 controller produced by Delta Tau as the hardware controller and constructs an open architecture CNC system with the structure of PC + motion controller.The main work of this paper includes the following contents:1.Completing the construction of open architecture CNC system based on PMAC motion controller: According to the functional requirements of five axis machining center,this paper configures the host computer,PMAC motion controller,servo motor and driver,spindle and rotary table and builds the hardware structure of the open architecture CNC system.2.Programming PLC and PID tuning: According to the built-in PLC function and PID algorithm of PMAC,this paper completes the programming of PLC and PID tuning for the requirements of the five axis machining center.3.Research on monotonically increasing back propagation neural network for NURBS curve interpolation: To solve the problems with existing method in interpolation process such as the low accuracy,heavy computation burden and large data storage,the monotonically increasing back propagation neural network is presented to fit the arc length and curve parameter.Note that the curve parameter is positively correlated with the arc length,the learning algorithm of back propagation neural network is modified to satisfy this property.After trained offline,the BPNN can generate the curve parameter efficiently,which sufficiently decreases the computation burden of real-time applications.4.Exploiting user interface: This paper makes use of Qt5.5 software to exploit user interface based on Windows platform.The user interface achieves the looking-forward feedrate planning,NURBS curve interpolation,the communication between IPC and PMAC and so on.