A hybrid approach for reliability allocation of NC machine tool based on meta-action

Reliability allocation is a critical process to ensure the reliability of numerical control (NC) machines during the design phase. However, there are a few issues with the reliability allocation techniques that are currently in use. First, the reliability allocation of NC machine tools still along the lines of "System-Component-Part," which is difficult to apply to the motion characteristics of machine tools and guide the product design effectively. Second, the consistency and objectivity of the reliability allocation technique based on multicriteria decision-making (MCDM) are inadequate due to the reliance on expert knowledge. Third, the reliability allocation criteria and reliability benefit are not taken into account by the allocation approach based multi-objective optimization (MOO), which leads to conservative allocation results. Therefore, this paper proposes a hybrid reliability allocation method based on meta-action for NC machine tools that integrates meta-action theory, MCDM, and MOO. In addition, the "conservative allocation" problem in the allocation process is addressed using the reliability benefit function. Finally, the rationality, effectiveness, and applicability of the proposed method are verified with the hobbing machine as an example through discussion and comparison.