Design Of Embedded Numerical Control System Based On ARM And FPGA

The embedded numerical control system has many advantages compared withtraditional computer numerical control system, it will be one of the developing directionof numerical control sysytem. Developing embedded numerical control system can helpto reduce the cost and improve the statbility and flexibility of a numerical controlsystem. In this paper, an embedded numerical control system was developed with ARMand FPGAmicroprocessors.Firstly, this thesis analyzed the merits and demerits of both embedded NC systemand traditional CNC system, thus expounded and proved the necessity of developingembedded NC system. After the analysis of four existing solution of embedded NCsystem, we determined the basic structure of the embedded NC system to be“ARM+FPGA” dual core control system. Then we designed the electric circuit of thecontrol system and made the print circuit board. This embedded control system wasused for the control of a three axis milling machine. After this, we built a integratedmilling machine control system to test the embedded numerical control system.In the next part of this thesis, we have developed the software system based on thedesigned ARM+FPGA hardware platform. Considered that ARM and FPGA are quitedifferent in their application circumstance, ARM processors are good at dealing withgeneral rutine and FPGA chips are good at IO ports controling, we decided to use ARMprocessor as host control unit and FPGA as slave control unit. The ARM system runs anembedded Linux with LinuxCNC as the numerical control software, so it can do manyjobs such as G code interpretation and interpolation algorithm. The FPGA chip was usedto expand the ports of the whole system, a pulse generator, an encoder counter and anIO controller was developed with Verilog HDL for the FPGA chip. In addition, thisthesis have developed a new kind of communication protocol for the two chips tocommunicate with each other.Finally, this thesis have tested the basic functions of the developed embedded NCsystem through processing wax pattern, thus proved the possibility of embeddedmicroprocessors using in numerical control systems.