Development Of Robot Motion Control System Based On Real-time Ethernet Technology

Industrial robots are now widely used in the actual industrial production,saving alarge amount of workforce and making large-scale automatic production line to bepossible. However, with the development of industry, the demands of controlprecision and flexibility of robots in application is higher and higher. Introducingrelatively mature technology of real-time Ethernet to industrial control field hasbecome a developing trend. Manufacturers of motion control system in American andEuropean countries have gradually released motion control system based on real-timeEthernet. However, every big manufacturer makes its system integrated andcustomizing, and its software functions are not allowed to be expanded and hardwareequipments are not allowed to be replaced. Then domestic enterprises not only haveserious limitations in application, also need to pay high on equipment purchase.In the status quo, puts forward a set of motion control solution with the moststreamlined framework based on PC. It Combines with automated software CoDeSysand real-time Ethernet technology EtherCAT, aiming at controlling robot with sixdegrees of freedom. It strives to achieve the openness and standardization of softwareplatform and hardware equipments to provide a set of motion control system, which ischeaper and wider in application and meets the requirements, for the domestic smalland medium-sized enterprises.First, analyzes the development of real-time Ethernet technology and itsapplication in the motion control field, then puts forward the implementation schemeof robot motion control system and emphasis on the functional advantages ofautomation software CoDeSys and the superiority of EtherCAT technology.Secondly, in order to get a thorough understanding of data structure andcommunication mechanism in EtherCAT technology, develops an IO communicationmodule independently, including the design of circuit diagram and writing devicedescription file and driver. Then proves the validity and reliability of the modulethrough the communication with soft master station.Finally, writes the motion control program about the robot with six degrees offreedom, completes the software and hardware configurations of the control system,and tests the movement performance of robot and communication performance of thecontrol system. The results show that the Robot can realize joint movement in the Joint spaceand straight line, arc and continuous line movement in the Cartesian space; Its repeataccuracy can keep within0.06mmin speed of50mm/s; Its System jitter time cankeep within12us; The average delay time through each slave station is about0.33us.And its master-slave communication type completely conforms to the EtherCATprotocol and the system has very high real time capability.