Research On The Industrial Ethernet Based Motion Control System

Motion control is a sub-field of automation and plays an important role on robotics and CNC machine tools. It is also widely used in the printing, packaging, textile and semiconductor industries. In this dissertation, an industrial Ethernet based open architecture motion control system is researched.First of all, the requirements of industrial Ethernet based motion control platform are analyzed, which contains the roles involved in development, application and integration of the system and their functional requirements. Then the system and software architecture are designed to satisfy the synchronicity of fieldbus on a general purpose computer. The system modules and their dependencies are described.Secondly, the study is focused on the application of industrial Ethernet to motion control system in both non-cyclic and cyclic communication process. The controller does not require install any specific hardware device, the precise cyclic signal is provided by the first node in the line topology, by which decrease the real-time requirement of the controller. The synchronicity between nodes is promised by dynamic time-delay compensation. Memory mapping based communication protocol and controller protocol driver are designed and implemented. Operation oriented application programming interface makes it possible for the control system to be extended in different layers drivern by the changed user requirement or the update of the platform itself. The performance test shows that the real-time requirement can be meet by the kernel programming on a general purpose operation system.Thirdly, the controller software architecture is discussed, in which logic control and functional implement are separated by using hierarchy finite state machine and multi-thread programming. The hierarchy finite state machine is implemented by.NET framework's delegate,^-expression and expression-tree. The conception of multi-layer state variable is put forward, which expands the semantic of the hierarchy finite state machine. CNC programing intermediate language is used to decrease runtime computation, find errors before execution, and prevent complicate logic decision. The function and implement of automatic mode is highlighted, which use hierarchy finite state machine to control the sophisticated process.Then, the method of complicate surface high speed manufacturing is studied, including time division based acceleration/deceleration interpolation algorithm, dynamic look-ahead algorithm. The experiment shows that the method is adaptive. When the angle between the segments is big, look-ahead algorithm limits the end speed of the segment that will make it decelerate, the residual length can be eliminate on the deceleration stage mostly. For those un-eliminated residual length is processed by connection between segments, which results smaller error due to limited end speed. When the angle between the segments is small, the segment end speed is limited by setting speed, which provides smooth feed rate.Finally, the research results are applied to a CNC engraving machine to perform systematic verification. Compare to other solutions, the system can be extended easily, enables flexible machine layout, and lowers the system cost. A batched method is presented to deal with large engraving CNC file, which can reduce the system memory usage and improve system response. The tool paths produced by CAM do not contain any entity information, which compose a wireframe model and can not be rendered in a 3D scene. We use a vertex coloring method to handle intensive three-dimension tool paths. An experiment is performed to verify the small segment high speed manufacturing algorithm.The successful implementation of this research provides an effective way to apply industrial Ethernet in motion control system. It gives a solution to design and implement open architecture motion controller.