Evaluation for the stability variation of the manufacturing process based on fuzzy norm method

摘要

In order to ensure the product quality and save manufacturing costs, growing attention has been paid to the problem of the stability of the manufacturing process with unknown probability distribution and trend. Considering that the stability of the manufacturing process is uncertain and its variation trend is unknown in the practical production, the evaluation for the stability variation of the manufacturing process can be performed by the measured data regarding to the product performance parameter based on the fuzzy norm method in this paper. The experimental investigation on the stability variation of the manufacturing process shows that if the relative error of the measurement uncertainty between the intrinsic sequence and the evaluated sequence is that dU≤15%, the manufacturing process is fairly stable; if 15%30%, the manufacturing process is unstable under the confidence level P=95.44%. The fuzzy norm method can be applied to enforce the real-time evaluation for the stability variation of the manufacturing process without considering the probability distribution, and the evaluation results can be expected to be of great interest for mass production.