Research on reliability allocation technology for NC machine tool meta‐action

Abstract

The reliability of machine tool is getting more and more attention. Reasonable reliability allocation is beneficial to improve the inherent reliability of machine tool. However, the existing reliability allocation methods for machine tool have some limitations. For example, static part is selected as the reliability allocation object of machine tool, which cannot reflect the characteristics "function realized by motion"; factors affecting reliability allocation are not considered comprehensively, weights of experts are treated as the same, and the allocation results are not optimized or the impact of time on enterprise is neglected in the optimization. To solve these problems, a new multiobjective optimization reliability allocation method for machine tool is proposed in this paper. Firstly, the latest achievements about meta-action are given, and meta-action is set as the reliability allocation object. Secondly, more reasonable and comprehensive factors affecting reliability allocation are extracted. Thirdly, expert weight coefficient is brought to reduce the subjective impact of expert scoring. Fourthly, time factor is brought to make the optimized allocation results more reasonable and accurate. Finally, a numerical control (NC) machine tool made in China is taken as an example, with a comparison on the reliability allocation results of current methods and proposed method. The results verify the applicability, rationality, and accuracy of the proposed method, which lays a foundation for the subsequent study on the quality characteristics of machine tool based on meta-action.

Research on meta‐action decomposition and meta‐action unit modeling technology for electromechanical product

“…12 After the meta-action of electromechanical product is obtained by FMA decomposition method, all the parts related to the 'motion' form of the meta-action are separated from the component assembly drawing, and the structural model composed of these parts is the meta-action unit. Meanwhile, it cannot be decomposed again and does not need to be decomposed in structure.…”

“…Meanwhile, it cannot be decomposed again and does not need to be decomposed in structure. 12 After the meta-action of electromechanical product is obtained by FMA decomposition method, all the parts related to the 'motion' form of the meta-action are separated from the component assembly drawing, and the structural model composed of these parts is the meta-action unit.…”

“…[5][6][7][8][9][10] The life cycle of electromechanical product is dynamic; the function and performance of the whole machine are realized by the function and performance of components, and the function and performance of the components are determined by the motion transfer relationship between parts. Meta-action unit is also called the meta-action structure unit, which is the smallest structure to ensure the normal operation of meta-action, 12 and also the smallest carrier of electromechanical product PAPRA. Meta-action is the most basic motion form to form the function of electromechanical product, and it is also the smallest 'action' unit to ensure the stable operation of electromechanical product.…”

“…After obtaining the meta-action of electromechanical product, the corresponding meta-action unit can be separated from the assembly drawing of the whole machine according to certain criteria. Meta-action unit is also called the meta-action structure unit, which is the smallest structure to ensure the normal operation of meta-action, 12 and also the smallest carrier of electromechanical product PAPRA. Meta-action and meta-action unit were first put forward by our team, and some achievements have been achieved, such as literature.…”

Reliability reallocation for cost uncertainty of fuel cell vehicles via improved differential evolution algorithm

“…When system reliability was required to reach the target value, Liu adopted genetic algorithm for FCV reliability reallocation. Li introduced expert weight coefficient to reduce the subjective influence of expert evaluation and put forward a new multi‐objective optimization reliability allocation method for machine tools. To expand the application scope of reliability allocation technology, Catelani systematically studied the reliability allocation from series architecture to redundant architecture.…”