Self-starting technology based production process quality control method

Abstract

The invention provides a self-starting technology based production process quality control method. The self-starting technology based production process quality control method includes calling statistic points beyond the range of control chart statistic point standard deviation 2 sigma as warning points, and setting the (m+1) point as a warning point, and subjecting a technological parameter matrix mean value mu to parameter estimation by means of prior m batches of data samples when the statistic points in follow-up samples are calculated, wherein a decision process is out of control if any point in the (m+2) and (m+3) statistical magnitude is also beyond the scope of 2 sigma, otherwise, the technological process is determined to be still in a control state, a formula (1) is used to calculate the statistical magnitude starting from the (m+4) batch of samples, and when the technological process is out of control, the probability that Q control chart statistic points are beyond a control limit is obviously increased. Particularly, when chart run length RL is <=5, a probability mass function of the run length is obviously increased, the probability of introduction of abnormal data is reduced to some extent, performances of the control charts are optimized, and production efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of industrial production, in particular to a production process quality control method based on self-starting technology. Background technique [0002] Statistical Process Control (SPC) is a commonly used quality control method in the production process. In the small batch production mode, the sample data of product quality characteristic parameters is less, but the establishment of the control chart requires a large amount of data. How to effectively apply SPC technology in the small batch production environment is the difficulty of quality control. [0003] In the prior art, foreign scholars have proposed a series of process control techniques based on Q statistics for small batch production mode——Q control chart. This research result has a profound impact on the field of process control. The Q control chart adopts the "self-starting" technology, and the control chart with self-starting characteristics do...

AI Technical Summary

Problems solved by technology

[0004] However, there is a defect in the self-starting technology: when the process parameter parent mean μ is unknown, the earlier the cause of the abnormality appears, the worse the detection ability of the control chart, or even the abnormality cannot be detected

However, the actual application results show that the improved effect is not ideal

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