基于元任务的数控机床运行动态可靠性评估技术研究

With the rapid development of science and technology, users of high-end CNC machine tools have become increasingly demanding, in many characteristic for measuring the quality of NC machine tools reliability is of the most concerned. The reliability assessment is the basis of the reliability research, but the research on reliability evaluation of NC machine tools is not enough currently, there is an absence of systematic theory and method for reliability assessment. This project takes high-end CNC machine tool as the research object, centered on the reliability modeling of operation process to establish a real-time dynamic model for reliability evaluation of NC machine tool operation process. Take decomposition of "general task - task group - task unit" as the breakthrough point, using the effects of multi-performance degradation on task as the means, to study index system and control mechanism for reliability evaluation of operation process of NC machine tools, establish a cooperative control model to ensure systematism in operation process evaluation, put forward a set of structured modeling technology to ensure dynamic evaluation of NC machine tool operation processes, and to provide theoretical and technical support for improving the reliability of domestic high-end CNC machine tools.

随着科技的飞速发展，用户对高档数控机床的要求越来越高，在衡量数控机床质量水平的诸多特性中，用户最关注的就是可靠性，而可靠性评估则是进行可靠性研究的基础，但目前对可靠性评估的研究还很不够，对数控机床可靠性评估还缺乏一套系统的理论和方法。本项目以高档数控机床为对象，以运行过程可靠性建模为主线，以建立实时动态反映数控机床运行时的可靠性评估模型为目标，以"加工总任务-元任务组-元任务"的结构化分解为切入点，以多性能退化数据对任务的影响规律研究为手段，系统研究数控机床运行阶段可靠性评估的指标体系和控制机制，建立综合保证实现运行过程可靠性评估的"系统性"协同控制模型，提出一套保障数控机床运行动态可靠性评估的结构化建模技术，为提高我国高档数控机床的可靠性提供理论和使能技术支撑。

本项目系国家自然科学基金青年项目（批准号：51305418），经过三年的研究，已按计划完成。项目针对现有数控机床可靠性评估无法准确反映机床实际动态可靠性的问题，以提高数控机床可靠性为目标，自顶向下，化繁为简，进行“加工总任务—元任务组—元任务—零部件”的结构化分解，将数控机床的加工任务分解至最基本的元任务层，并以元任务完成单元为对象分别对各级任务的可靠性建模进行了深入研究。再由下至上对整机运行过程进行建模，建立了数控机床运行过程的可靠性动态模型。最后建立了可靠性评估模型。具体研究内容包括：. （1）建立了数控机床结构化分解的模型，包括结构化分解的流程、原则等；. （2）建立了数控机床运行过程的可靠性模型，包括元任务的可靠性模型，元任务或元任务组之间的耦合关系模型，整机运行可靠性模型；. （3）建立了数控机床的动态可靠性评估模型。. （4）建立了面向合作企业的数控机床可靠性管理体系，为提高我国高档数控机床的可靠性提供理论和使能技术支撑。完成了应用研究。