Research On Key Techniques Of The NC System For Micro-injection Tag Machine

Micro-injection tag,namely,multicolor plastic tag,is so called because it is often produced by micro-injection technique.It is widely applied and in great demand. However,its production is still originally performed by hand.Thus it is significant that developing an automatic production equipment.Using numeric control(NC) technique could realize the automation of micro-injection tag's production.According to the requirements of micro-injection tag's production,the NC system should possess the features of low cost,high performance,small volume and friendly interface.The key techniques of the NC system was researched in this thesis,the framework of the NC system was given,an approach for machining path optimization based on Variable-Length Genome Genetic Algorithm was presented,and the embedded controller of the NC system based on ARM7 S3C44BOX andμC/OS-Ⅱwas developed,this kind of NC system could meet the requirements of micro-injection tag's production very well.The main work and contributions in this dissertation are as follows.Firstly,micro-injection tag and the present situation of its production ware introduced,the approach for the tag's automatic production based on NC technique was pointed out,and the NC technique was introduced briefly,then the advantages of the application of embedded technique in NC system was discussed.Secondly,the framework of the NC system was given,which was a serial network consisted of a host computer and many embedded controllers.The NC system included a NC code generating software installed in the host computer,embedded controllers,machine tools and micro-flow controller.The embedded controller adopted open loop control mode,and the actuating mechanism was consisted of stepper motor and ball screw,this architecture could not only met the precision requirement but also kept the cost of the NC system very low.Thirdly,every module's function of the NC code generating software was defined, and the key techniques of the software were researched.An approach for machining path optimization based on Variable-Length Genome Genetic Algorithm was presented.In this algorithm,each machining element was represented by some points which were encoded into a combination of an index and its attribute,and some kinds of lines could be cut and spliced by the crossover and mutation operation,thus the machining paths could be further optimized.Simulation results show that this approach is effective for the problem of machining paths optimization,it can dramatically shorten machining paths.Fourthly,the embedded controller of the NC system was developed.This controller's hardware was consisted of ARM7 S3C44BOX,AT89C52 and TA8435; for the software platform,μC/OS-Ⅱoperating system(OS)was adopted,and the application software was divided into several function models which were assigned different priorities as tasks in the OS.This architecture and the use of buffer could provide perfect real time capabilities which could meet the requirement of micro-injection tag production very well.Lastly,the research contents of this dissertation were summarized,and what the NC system needs to be improved was pointed out.