基于可用性建模的数控机床主动维修决策方法研究

数控机床的功能故障和性能故障都是影响可用性和维修决策的重要因素，但是目前广泛应用的以可靠性为中心的维修并未考虑性能故障等问题；元动作分解是基于数控机床精细化动态控制提出来的一种新方法，从功能运动的角度对数控机床进行分解，使建模和故障分析更精准，但尚未解决基于元动作单元的可用性建模与维修决策等问题。因此，本项目以可用性为中心，以元动作单元为基础，通过动力学仿真对元动作单元的故障形成机理进行分析，对可用性进行表征并构建其参数模型；接着采用试验手段对元动作单元的性能特征及故障征兆进行研究，分析它们与故障之间的映射关系，构建基于元动作单元的数控机床可用性综合评估模型；然后以可用性为约束条件，建立元动作单元预防维修周期和预测维修时机模型，并分析元动作单元相关性，构建数控机床维修决策优化模型；最终形成一套以可用性为中心基于元动作单元的数控机床主动维修决策方法，为提高数控机床的可用性提供理论和技术支撑。

Functional fault and performance fault are both important factors affecting CNC machine tools’ availability and maintenance strategy. However, the Reliability Centered Maintenance (RCM) widely used nowadays does not take performance fault into account. Meta-action decomposition is a new method to decompose CNC machine tools from the perspective of function and motion, which is proposed on the basis of CNC machine tools fine dynamic control, and can help modeling and fault analysis more precise. But the problems of availability modeling and maintenance strategy based on meta-action unit have not been solved. Therefore, with availability setting as center, meta-action unit setting as basis in the project, the fault formation mechanisms of meta-action unit were analyzed by dynamic simulation, availability was characterized and the parameter models were established firstly. Secondly, the performance characteristics and fault symptoms of meta-action unit were studied by experiments, and the mapping relationships between them and faults were analyzed, then the availability comprehensive evaluation model of CNC machine tools was built based on meta-action unit. Considering availability as constraint condition, the preventive maintenance cycle and predicted maintenance time models of meta-action unit were established, and maintenance strategy optimization model of CNC machine tools was built based on meta-action unit correlation analysis. Finally, the strategy method of availability centered proactive maintenance based on meta-action unit for CNC machine tools was formed to provide theoretical and technical support for improving availability.