Design Of An Ethercat Based Multi-axis Motion Controller

Motion controller is the core of digital system to achieving precision motion control and the key equipment of CNC Machine Tools. With the advances in electronic technology and network communication technology, motion control systems are moving towards to open-source, open technology and high rapidity. Therefore, the traditional motion controllers can’t meet the needs of the development of modern manufacturing. One of the main research focuses is multi-axis motion control system of real-time Ethernet in technologic and industrial fields. In this thesis, we design an EtherCAT based multi-axis digital motion controller, after systematically study on industrial Ethernet technology. Scheme for the Overall Design of motion controller was proposed and the hardware and software of motion controller was designed in the thesis.On the design of the hardware, the core processor used was STMicroelectronics make STM32F407ZGT ARM chip, while Altera make EP4CE10E22C8 FPGA chip was used as the coprocessor. The ET1200 chip was used to implement the EtherCAT communication link layer, and realized the communication function between master station in PC and slave station of motion controller. In the thesis, we designed the circuit modules, including the Ether CAT slave network interface module, motion control module and the power supply module.The software framework of motion controller is designed based on the developed hardware. The EtherCAT slave drive and command parsing program were designed in an ARM chip embedded into a μC/OS-Ⅱ operating system by C language. The technology of position control, S-type speed planning and interpolation was researched in the QuartusII by Verilog HDL.The drawing and production of PCB were completed on the basis of hardware design, and the controller prototype is made. A test platform used to verify the normal function of each module in hardware and software was built.Master station in PC was designed. The tests of EtherCAT communication, position control, encoder feedback, S-type speed planning and two-axis interpolation were completed. The result shows that the motion controller meets expectations.