Design Of EtherCAT Based Multi-axis Motion Controller

Motion controller is the core of digital system，because its performance directly affectsthe quality of CNC maching equipment, and has a crucial impact on the entire manufacturingsuch as integrated control, efficient operation and update. The rapidity, stability and opennessof traditional motion controllers are unable to meet the development demand of modernmanufacturing industry. Multi-axis network control systems have been one of the mainresearch focuses in academia as well as in industry for many decades and have become amultidisciplinary area.In this thesis, we design an EtherCAT based multi-axis servo motion controller, aftersystematically study on industrial Ethernet technology, especially EtherCAT networkcommunication technology. The controller engages EtherCAT as high speed industrial motionnetwork to enable both the motion control in real-time and the data transmission in high-speedand efficient. We focus on the detail design of hardware and software of the multi-axis motioncontroller in the thesis.In respect to the hardware design, the TMS320F28335DSP chip is used as the coreprocessor, which is dedicated to industrial control. The EP2C8Q208C8N FPGA chip is usedas the coprocessor. And the ET1100chip is used to implement the EtherCAT communicationlink layer, on which slave EtherCAT interfaces are designed. In the thesis, we design thecircuit modules based on the control scheme, including the DSP+FPGA servo control module,Ether CAT slave network interface module and the power supply module.In respect to the software design, we modularly partition and design the controller’software based on the functional requirement, focusing on the research of EtherCAT slavedrive, information acquisition, analog output, position control and trajectory interpolationtechniques. Meanwhile, we design a two-stage interpolation algorithm, rough interpolationexecuted by DSP and finish interpolation executed by FPGA.At last, we make some samples of the motion controller on the ground of our hardwaredesign. Furthermore, we build the test platform by the sample to perform some tests for thehardware and software, which aims at verifying the hardware principle and achieving thedesired motion control effect as well as laying good foundation for further research.