A Design Of Open-CNC System For Plasma Powder Deposition Manufacturing Facility

PPDM(Plasma Power Deposition Manufacturing) is a method of direct rapid metal manufacturing and tooling,it can sharply shorten the lead-time,reduce the cost of product and shape up full-density metal die, therefore it has great future in the RM & Aero-Part industry. Because a lot of factors disturb the processing of PPDM, these is a long way to go to improve the precision of production. To ravel out the dimension defect of product, developing an Open-CNC system and doing a closed-loop control with deposition for PPDM is vital problem. Our research team has successfully developed that special CNC system based on"IPC + motion controller"control mode. The CNC system achieves great motion performance, it can satisfy the processing and analyzing.PMAC2A-PC104, the kernel part in the CNC system, realizes five axes gang control of eight coordinate in manufacturing instrument. In this paper, an advanced control strategy is proposed to drive the Panasonic AC-servo system. High-speed communication is achieved through shared DPRAM. The interface technique of PMAC to servo units and encoders has been clearly introduce. By the hardware circuit interface, furnished the position following function of handwheel-impulser, and realizes the main axes feed-speed tuning and direction changing.The software subsystem consists of two modules: the real-time control and the system management. The real-time control module, which is intended to achieve real-time control of PMAC motion control system, includes variable initialization, PLC program and G code interpreter program. The system management module, which is intended to achieve system resource assignment and programs dispatching, includes high-speed communication with PMAC by using DLL technology and controllable send G code to PMAC. Meanwhile all key parameters are clearly displayed to user, it is great convenient for user to comprehend the process of PPDM.The computer control subsystem possesses self-contained control function, not only satisfies the critical requirement of a CNC system, but also meet with all the condition of PPDM, it is a highly integrated system. Moreover, its high openness provides a broad platform to make function expansion.