Research And Development Of CNC Based On DSP And FPGA

Recently, with the development of micro-electronics, CNC is developing towards generalization and miniaturization. Now, CNC based on DSP and FPGA are becoming popular, which can combine the strongpoints of both DSP and FPGA. On one hand, as kernel controller of CNC, DSP with its high speed operation and flexible programmable ability is convenient for carrying out complicated real-time algorithm. On the other hand, a lot of control logic and components of peripheral circuit can be integrated within FPGA, which can result in the volume minishment of the system and the enhancement of the system's reliability and stability.After comparing some different hardware architecture of CNC, a four-axis closed loop CNC based on DSP and FPGA was developed in the thesis.Firstly, the hardware structure of the CNC is given based on the analysis of requirements. The hardware design is discussed in detail, such as the peripheral circuits of the DSP and FPGA, the digital pulse output circuits, the analog output circuits, the encoder input circuits and the interface circuits of general purpose I/O. In order to enhance the integration and the reliability of CNC, by programming to FPGA, many function units are designed and implemented within a FPGA, including S curve acceleration/deceleration control, DDA fine interpolation circuits, DAC interface circuits, encoder signal processing circuits, manual pulse generator signal processing circuits, digital I/O signal processing circuits and dual port RAM. These function units all pass test and debug.Finally, based on mentioned hardware, some of software of CNC, including test programme of DSP and HMI software of MCU, was developed with modularization method and C language. Associated test of hardware and software of CNC was accomplished at last.