Research On Embedded Numerical Control System And Look-Ahead Controller

This dissertation deals with the study of embedded numerical control (NC) system. Two key problems, software for embedded numerical control system and the look-ahead control technology, are studied in detail. In paper, the requirements of an embedded NC system are analyzed first, and then designs of hardware and software are introduced. Based on the design, how to implement NC software using ARM-Linux operation system is discussed, and the graphical user interface (GUI)'s design is specially presented. Finally, a look-ahead control technology is joined in embedded NC system to avoid gouging and mechanical vibration caused by high curvature of toolpath in high speed machining. The experiment proves the validity of the method proposed in this paper.Chapter 1 is an exordium. It summarizes the outline of embedded system, the state of the art in embedded NC system and its development trend. The look-ahead control's present research situation is introduced in the domestic and foreign NC system. It also proposes a look-ahead control technology joined in the embedded NC system. Finally, the main content of this dissertation is presented.In chapter 2, structure of embedded NC system is described. Through the system requirements analysis of embedded NC system, hardware and software's system designs are determined. How to divide functional modules of the software system and choose the embedded operating system are introduced.In chapter 3, software of embedded NC systems is designed. The principal and subordinate control mode is introduced first, and then the software's development pattern is described simply. Finally, control software's design and realization is introduced in detail, including code compilation thread, processing control thread and design of PC/104's device drivers.In chapter 4, how to design GUI for embedded NC system is studied. The QT/E development environment is described, and each module's design and implementation are discussed. In chapter 5, a look-ahead control technology is introduced. To solve some questions of continuous micro path sections processing, a look-ahead control technology is proposed. The most important speed constraints and the processing step in look-ahead control are discussed in detail.In chapter 6, an experiment with look-ahead control technology based on embedded NC system is conducted. It introduces experiment's hardware and software system, and a look-ahead control model is established. Experimental results are compared and analyzed.Finally, summary and prospects are given in chapter 7. The study contents and conclusions of the dissertation are summarized, and the further research works are forecasted.