Study Of Key Technologies For Embedded CNC System Design Based On Model Integration

CNC technology is the acceleration and foundamental equipment for high-tech development. As the brain of machine tools,CNC system determines the functions as well as the performances of the CNC machine to a degree. Recent trends of CNC system development call for products with properties of high-speed and high-accuracy,intelligentize,multifunctional , multitask as well as open architecture. What's more , the rigorous performance requirements make the CNC system development becoming more and more complex. Traditional development methods for CNC system were sequential process based on the hand coded programming,in which the design and realization depends on the experience of engineers. Design steps such as motion programmming, motion control algorithm, circuit design, software progamming are carried out independently, and systematic design guidance and verification is absence. These shortcomings brought to a series of problems. The correctness and reliability cannot be guaranteed in earlier develop stage without verification, and the test and redesign time will be prolonged. Moreover, the reusability and reconfigurability is hard to be realized lacking formalized componentization.Aims to address the restrictions imposed by traditional development approaches,a CNC model integration framework (CNCMIF) is proposed. According to the CNC domain analysis,the CNC system modeling language(CNCML) is built using domain specific modeling method. The functional and perforamance abstracion for CNC system is utilized in sake of modeling CNC system in an accurate and explicit way. Formal functional simulation and performance verification in the third tools can be realized based on the formal description. Automatic code synthesis can be carried out engaging the code generation interpreter.Based on CNCMIF,the CNC system modeling language(CNCML) is built,and the CNC domain graphical modeling environment is generated. Components with different granularity are defined in CNCML domain space . Multi-view integration model is adopted to describe the CNC system in different aspects, including function view model, platform view model and runtime view model. The inter-view communication and coupling is defined in the multi-view integration platform. The non-functional properties such as time and resource oriented attributes are attached to the modeling elements and behaviors. The formal space of CNCML utilizes model of computation(MOC) to describe the various operation behavior in CNC system. Several MOC semantic units is defined for specific verification. What's more the formal semantic model is integrated to the CNC domain model using model transformation method, which makes the formal verification automatic.Then, a metrics system for quantifying operational coupling is proposed for CNC system, which used to evaluate the reconfigurability in CNC system design. A preferable component-based system with better reconfigurability can be comfirmed by measuring the coupling of the system. The reconfigurability of two lathe CNC system with different structure was evaluated using the metrics system.Lastly, the CNCMIF is verified by a lathe CNC system building case study. The CNC lathe system application model is built in the CNC domain graphic modeling environment. The formal simulation and verification is carried out and the automatic code synthesis is conducted. Two lathe CNC systems with different structure is reconfigured. By comparing the difficult degrees of the two reconfiguration, the coupling metrics system is verified. The functional and performance test is carried out by a CNC Lathe prototype. The results indicate that the CNCMIF is an effctive integration platform for CNC system development. The reconfiguration can be ensured with the formalized componentization. The reliability of the embedded CNC system can be guarranteed by the formal functional and non-functional verification before the application implementation. The development effciency can be greatly improved by the automatic code generation with interpreters.