Design And Implementation Of Servo Drives Based On EtherCAT Communication

With the advancement of Made in China 2025 and Industry 4.0,bus-based servo control systems have been widely used in industrial robots,CNC lathes and other equipment.However,as the number of servo devices connected to the bus increases,the drawbacks of traditional fieldbus technology such as high latency and poor redundancy are gradually revealed.In order to solve these problems,Beckhoff has developed a new industrial Ethernet-based bus technology-EtherCAT in recent years.In this project,EtherCAT communication technology is applied to the AM437 x chip-based servo drive system on the basis of industrial fieldbus research.The AM437 x chip developed by TI is used as the main control chip of the servo drive system.The integrated PRU programmable kernel of the chip can realize the ESC hardware function of EtherCAT,and the supporting software functions are designed and developed.（1）Servo hardware,from the system master circuit design,EtherCAT slave communication circuit design and servo drive circuit design three aspects introduced based on the AM437 x chip developed by TI as the master chip of the servo drive system as the master chip hardware scheme.（2）As for the software of the servo system slave,the EtherCAT application layer program,Ci A402 motion control architecture and motor vector control program are designed and developed based on the SDK development kit and EtherCAT standard protocol stack provided by TI.According to the hardware conditions of AM437 x chip,the matching slave ESI description file is written.（3）For the software of the servo system master,key variables were linked to the IO layer,NC axis layer and PLC axis layer of the master,the PLC program based on TwinCAT PLC was designed and the supporting HMI interface was developed,and a control process for cyclic reciprocating motion was implemented.（4）In the experimental part,a platform was built to verify the performance of the single-axis servo drive based on EtherCAT communication.The EtherCAT master based on TwinCAT3 was built on a PC,and the performance of the EtherCAT network communication between the designed servo slave and the master was verified mainly in terms of frame length and delay time,cycle time,clock deviation or distributed clock jitter and slave safety of the EtheCAT network communication;the performance of the TwinCAT3 software designed in this paper was verified in the NC The position and velocity following performance of the slave servo system is verified in the CSV and CSP modes of the TwinCAT3 software designed in this paper.Experiment of single-axis cyclic reciprocating motion control based on soft PLC.The experimental results show the effectiveness of the designed servo drive system based on EtherCAT communication.