Development Of The CNC System With Multi-Channel Capability

The functions of metal cutting machine tools have been increased to meet the growing demand of productivity in machining complicated parts on one machine. This thesis presents a design for the numerical control device capability of the multi-channel, based on the open architecture of CNC. With complex application model analysis, this frame is completed by building of physical model of devices, researching the control module of kernel and designing the human-machine interface.By researching the characteristic of complex machining and the techniques of concurrent control, synchronous control, swapping control together with superimposed control, a software framework of CNC system with multi-channel capability based on the Linux platform is presented by using the MVC design pattern and referring to OMAC. The relationships between modules and the data model of the control objects are discussed mainly on the framework.Based on priority, the scheduling of modules in control module is analyzed. The FMS (Finite State Machine) of channel is designed to switch the channel mode. For synchronous control, the strategy of global mark operation has been studied in decoding module. The model of axes relationships is build for superimposed control in axes group module. With the design of the control status of axis in axis module, the swapping control could be completed.The basic design principles for the layout of multi-channel HMI and the operation of control panel are discussed before designing the parameter configuration interface used to map the channel unit of logic layer to the control object of physical layer. By studying the solutions for user programming of multi-channel control, the new G-code formats of the axis programming name and of controlling the channel, the new PLC elements expanded with channel information, the Macro for sharing the variables and on-line simulation for detecting the interference are presented in human-machine interface.Through the simulation and actual machining, it is verified that the method of multi-channel control presented in this thesis would complete the complex job.