Research Of The Master Motion Controller Based On EtherCAT

The motion controller is mainly used in the field of industrial control,and it is the core equipment for industrial control system to realize the precise motion control.Since twenty-first Century,with the rapid development of computer technology and automation technology,the motion controller has undergone profound changes.At this time,the traditional motion controller,which is generally based on PCI bus or ISA bus,when a long distance transmission,not only has the problem that communication signal is susceptible to be interfered and the real-time is poor,but also has the problem that the precision of linear interpolation and circular interpolation it supports is low about complex curves.All of this problems lead to the traditional motion controller cannot meet people's needs.In order to solve above problems the traditional motion controller has,this thesis first uses Ether CAT bus technology to design the Ether CAT master station of the motion controller,then it can communicate with Ether CAT slave station through the Ether CAT bus,if so,the problems that poor communication signal and low real-time can be solved.In order to solve another problem that the motion controller is low in precision when some complex curves are interpolated,in this thesis,an interpolation algorithm,which is spline curve interpolation algorithm,is redesigned to improve the interpolation precision of the motion controller.The specific research contents of this thesis are as follows:First of all,the Ether CAT master module of the motion controller is designed in detail.Since the design of the master station is done by configuration software on the PC,the Ether CAT master module only needs to make the motion controller support the Ether CAT bus protocol.This is achieved by integrating the com X protocol board on the motion controller.Because the Ether CAT bus technology is the enhancement and improvement of the Ethernet technology which not only has a high transmission rate but also a stable signal when a long distance transmission,so the Ether CAT master of the motion controller communicate with Ether CAT slave via Ether CAT bus can solve the problems that the communication signal is poor and the real-time is low.Second,the algorithm module of the motion controller is designed in detail.The algorithm module mainly calculates the coordinate value or displacement increment of the interpolation point on the NC trajectory,then controls the movement of the slave station towards the direction of the NC trajectory planning.The algorithm module is designed using the NURBS spline interpolation algorithm.Based on some excellent properties of the NURBS curve,the motion controller has better interpolation precision than the linear interpolation or the circular interpolation when interpolation is performed on complex curves or surfaces.Third,after the design of the Ether CAT master module and algorithm module,the motion controller system is divided into the following three modules: real-time operation module,algorithm module and Ether CAT master module,and each of the three modules is realised individually.Forth,the hardware frame of the motion controller is introduced briefly,and an experimental test platform is set up.The basic functional test and performance analysis about the Ether CAT master module and the algorithm module of the motion controller are completed respectively.The final experimental data show that the design of the motion controller based on Ether CAT master station is feasible to achieve the desired goal.