Data management device for precise quality control
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorAtsushi Fukumoto
Life of this patent
Estimating the term…
Abstract
A quality control method includes the steps of calculating average X and standard deviation σ of quality control data, excluding abnormal data outside a range represented by (average X±4σ), calculating average X and standard deviation σ of the quality control data except for the abnormal data, determining N in (average X±(2.5+0.1×N)σ) representing a region so that the ratio of the number of data outside the region relative to the number of all data is 0.015 or less, using the calculated N to set alarm standards at (specification center E±(2.5+0.1×N)σ), and preparing quality alarm information when any data is found outside the alarm standards.
Claims12
A data management device comprising:
- storage means for storing data;
- first calculation means for calculating average X, standard deviation σ and the number of all data except for abnormal data in said data stored by said storage means;
- second calculation means for calculating the number of partial data of said all data, said partial data being outside a region of a range defined by a function of said standard deviation σ with said average X as a center;
- third calculation means for calculating a function of said standard deviation σ representing a region where the ratio of the number of said partial data relative to the number of said all data is equal to a predetermined ratio or less;
- and
- first output means monitoring measured data according to said calculated function of said standard deviation σ for outputting an alarm for said measured data.
A data management device comprising:
- storage means for storing data;
- first calculation means for calculating average X, standard deviation σ and the number of all data except for abnormal data in said data stored by said storage means;
- second calculation means for calculating the number of partial data of said all data, said partial data being within a region of a range defined by a function of said standard deviation σ with said average X as a center;
- third calculation means for calculating a function of said standard deviation σ representing a region where the ratio of the number of said partial data relative to the number of said all data is equal to a predetermined ratio or more;
- and
- first output means monitoring measured data according to said calculated function of said standard deviation σ for outputting an alarm for said measured data.
Dependencies are inferred from the claim text.