Developing a virtual machining model to generate MTConnect machine-monitoring data from STEP-NC

The ability to predict performance of manufacturing equipment during early stages of process planning is vital for improving efficiency of manufacturing processes. In the metal cutting industry, measurement of machining performance is usually carried out by collecting machine-monitoring data that record the machine tool’s actions (e.g. coordinates of axis location and power consumption). Understanding the impacts of process planning decisions is central to the enhancement of the machining performance. However, current methodologies lack the necessary models and tools to predict impacts of process planning decisions on the machining performance. This paper presents the development of a virtual machining model (called STEP2M model) that generates machine-monitoring data from process planning data. The STEP2M model builds upon a physical model-based analysis for the sources of energy on a machine tool, and adopts STEP-NC and MTConnect standardised interfaces to represent process planning and machine-monitoring data. We have developed a prototype system for 2-axis turning operation and validated the system by conducting an experiment using a Computer Numerical Control lathe. The virtual machining model presented in this paper enables process planners to analyse machining performance through virtual measurement and to perform interoperable data communication through standardised interfaces.     

MTConnect compliant monitoring for finishing assembly interfaces of large-scale components: A vertical tail section application

Monitoring is a significant issue for finishing the assembly interfaces of large-scale components before final assembly. Acquisition and supervision of the pivotal data is essential to ensure the security and reliability for machining the large and complicated components with high-value. This process is generally cumbersome and time-consuming because there are various types of data coming from different components and sensors. The problem becomes more serious when considering the whole shop floor. Recently, MTConnect has been proven to be an effective method to realize standardized data collection and monitoring process. However, MTConnect is still under development and cannot cover the whole finishing process such as on-machining measuring (OMM) and fixturing. To address the issue, an MTConnect compliant method with extended data models is proposed in this paper to implement a standardized monitoring system. Firstly, a finishing system for the assembly interfaces is introduced, including the framework, workflow and key procedures and data. Then extended MTConnect data models are proposed to represent the finishing system including on-machine touch-trigger probe and sensor-based intelligent fixturing related information. Based on the extended MTConnect data models, a web-based monitoring system is developed for data collection and monitoring by combining an MTConnect agent and an OPC adapter. The proposed approach is validated by collecting and monitoring the key process data using an airplane vertical tail as an application. The advantages of using MTConnect would be more significant when extended to the entire factory and implemented in cloud manufacturing in the future.     

基于MTConnect的装备建模标准化与互联互通互操作

针对装备源数据异构、共享难度大、互联互通互操作成本高等问题,提出基于MTConnect的数控装备建模标准化和互联互通互操作方法。提出可扩展的装备异构信息统一描述语义和面向MTConnect的信息模型映射方法,实现了异构装备的可扩展标准化建模。在信息模型映射基础上,提出集成可配置的中间件设计、基于超文本传输协议的数据获取和基于Interface组件的装备互操作技术,降低了装备互联互通互操作的难度。搭建包含多类主流数控系统的试验验证平台,验证了所提架构、方法、技术在纵向互联互通和横向互操作的可行性,相比直接驱动的互联互通互操作,具有更好的安全性、扩展性和易用性。     

基于MTConnect的数控机床网络化监控技术

为实现制造设备的广泛互联和远程监控,研究了利用MTConnect进行设备联网的基本方法,包括监控系统的实现架构、设备信息模型和信息采集流程.设计了一个符合MTConnect要求的数控雕刻机远程监控系统,该系统能够利用代理端和客户端的通讯通过Internet实时收集数控雕刻机的数据.分析了该机床的具体组件和属性,根据MTConnect建立了该机床的设备模型,并用可扩展标记语言编写相应的描述文件.采用C#语言和制造技术协会提供的开发工具研发了MTConnect代理端、客户端以及必要的数据处理和可视化软件模块,从而实现了该系统.通过实际加工和监控对该系统进行验证,结果表明,该系统能够方便、可靠地获取联网机床的运行信息,从一个侧面证实了MTConnect方法的可行性和有效性.