Study On Key Technologies Of Intelligent Dispensing System

Dispensing system is a system that dispenses quantitative glue to an assigned position along the reserve trajectory in a way to control its working speed and dispensing volume. In this dissertation, some theories, key technologies and approaches to realize them, related to a graphics programming system, are emphasized. These related theories and key technologies are drawing data extracting from DXF technology, dynamic data storage technology using single linked list, plane recognition, ordering and dispensing movement path optimization based on data, AutoCAD secondary development technology, NC interpolation theory, motion simulation technology and serial communication technology, etc.The methods to exchange drawing data between different CAD systems are discussed. The drawing data exchange standards often used are compared. The structure of the DXF file and the implication of its content are studied. The approaches to dispose DXF files using VB are analyzed. Based on the above research results, a data extraction algorithm suitable for graphics programming system is put forward.Three kinds of computer data storage structure are analyzed. The methods to structure linked table in the programming languages without pointer are discussed. And their merits and drawbacks are compared. An approach to structure dynamic single linked table using VB is put forward. The dynamic single linked table can be used to store drawing data. The coordinate system of meaning, usage and coordinate transformation methods are introduced. The plane recognition algorithm and plane sorting algorithm are put forward based on DXF.The algorigthm to recognize the repeating path and the segmenting path in line path, circular arc path and ellipse arc path, and the methods of dispensing path optimization are analyzed in detail according to the technological requirements of the dispensing process and characteristics of the drawing data.The advantages and disadvantages of pulse incremental interpolation theory and principles of digital incremental interpolation are compared. The interpolation strategy suitable for the graphics programming system of dispensing system is discussed. The linear interpolation algorithm based on the principles of digital incremental interpolation, the circular arc interpolation algorithm and the ellipse arc interpolation algorithm based on center angle division idea are put forward.Accoding to dispensing process requirements, the simulation environment modeling and simulation process realization approach is introduced based on AutoCAD secondary development technology.The computer bus communication often used is discussed. The method to connect serial communication hardwares of dispensing system and the method to build serial communication software are introduced. An asynchronous communication protocol is developed according to the drawing data characteristics and the dispensing process requirements.The functions of the graphics programming system of dispensing system has been developed according to the results of these researches. These functions are to extract drawing data, recognize and sort dispensing plane, optimize and interpolate dispensing path, simulate dispensing movement and communicate.The software developed has a friendly interface, characteristics of flexible operation. In software designing, VB6.0 was taken as a programming platform, the object-oriented programming ideas and modular programming method being fully used, so that the program has a strong flexibility and replaceability. Although the dispensing system is taken as background in developing the graphics programming system, many functions of the system have generality so as to be applied to other NC systems.