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US 6,862,484 B2Granted
Controlling method for manufacturing process
AssigneeOki Electric Industry Co., Ltd.
InventorShunji Hayashi
Life of this patent
Estimating the term…
Abstract
In a method of controlling a manufacturing process, a Mahalanobis space of plural manufacturing control parameters is generated on the basis of first sampled data. Then, a Mahalanobis distance from the Mahalanobis space and second sampled data is calculated. A manufacturing process is determined to be under a malfunction operating condition by comparing the Mahalanobis distance and a threshold value.
Claims10
A method of controlling a manufacturing process, comprising:
- providing first sampled data which indicates a sampled data group by sampling a plurality of manufacturing control parameters under a normal operating condition of the manufacturing process, which includes a plurality of process steps;
- generating a Mahalanobis space of the plurality of the manufacturing control parameters, based first sampled data;
- providing second sampled data which indicates a sampled data group by sampling the plurality of manufacturing control parameters at constant time intervals, during the manufacturing process;
- calculating a Mahalanobis distance from the Mahalanobis space and the second sampled data;
- making a decision that the manufacturing process is under a malfunction operating condition when the Mahalanobis distance is more than a threshold value;
- calculating displacement quantities for each of the manufacturing control parameters from an average of the Mahalanobis space;
- and
- determining a degree of incidence of the malfunction operating condition for each of the plurality of process steps, in accordance with the displacement quantities for each of the manufacturing control parameters.
5 more elements
A method of controlling a manufacturing process, comprising:
- setting ideal data of plural manufacturing control parameters of the manufacturing process which includes a plurality of process steps, and a permissible range of the ideal data;
- generating random numbers within the permissible range of the ideal data;
- generating Mahalanobis spaces for each of the plural manufacturing control parameters, based on the random numbers;
- providing sampled data which indicates a sampled data group by sampling the plural manufacturing control parameters at constant time intervals, during the manufacturing process;
- calculating Mahalanobis distances from the Mahalanobis spaces and the sampled data;
- determining a degree of divergence from an ideal operating condition of the manufacturing process, by comparing the Mahalanobis distances and a threshold value;
- calculating displacement quantities for each of the manufacturing control parameters from an average of the Mahalanobis spaces;
- and
- determining a degree of incidence of a malfunction operating condition for each of the plurality of process steps, in accordance with the displacement quantities for each of the manufacturing control parameters.
6 more elements
A method of controlling a manufacturing process, comprising:
- providing first sampled data which indicates a sampled data group by sampling a plurality of manufacturing control parameters under a normal operating condition of the manufacturing process, which includes a plurality of process steps;
- generating a Mahalanobis space of the plurality of the manufacturing control parameters, on the basis of the first sampled data;
- providing second sampled data which indicates a sampled data group by sampling the plurality of manufacturing control parameters during the manufacturing process, at constant time intervals;
- calculating a first Mahalanobis distance from the Mahalanobis space and the second sampled data;
- generating a selected group of combined parameters the plurality of the manufacturing control parameters;
- calculating a second Mahalanobis distance from the Mahalanobis space and the selected group of combined parameters;
- and
- determining a degree of incidence of a malfunction operating condition for each of the plurality of process steps, in accordance with a displacement quantity of the second Mahalanobis distance from the first Mahalanobis distance.
5 more elements
A method of controlling a manufacturing process, comprising:
- setting ideal data of plural manufacturing control parameters of the manufacturing process which includes a plurality of process steps, and a permissible range of the ideal data;
- generating random numbers within the permissible range of the ideal data;
- generating Mahalanobis spaces for each of the plural manufacturing control parameters, based on the random numbers;
- providing sampled data which indicates a sampled data group by sampling the plural manufacturing control parameters at constant time intervals, during the manufacturing process;
- calculating Mahalanobis distances from the Mahalanobis spaces and the sampled data;
- determining a degree of divergence from an ideal operating condition of the manufacturing process, by comparing the Mahalanobis distances and a threshold value;
- and
- storing information provided by a control method for the manufacturing process, into a host computer through a local area network, wherein the information is accessible from a plurality of servers through an intranet.
5 more elements
A method of controlling a manufacturing process, comprising:
- setting ideal data of plural manufacturing control parameters of the manufacturing process which includes a plurality of process steps, and a permissible range of the ideal data;
- generating random numbers within the permissible range of the ideal data;
- generating Mahalanobis spaces for each of the plural manufacturing control parameters, based on the random numbers;
- providing sampled data which indicates a sampled data group by sampling the plural manufacturing control parameters at constant time intervals, during the manufacturing process;
- calculating Mahalanobis distances from the Mahalanobis spaces and the sampled data;
- and
- determining a degree of divergence from an ideal operating condition of the manufacturing process, by comparing the Mahalanobis distances and a threshold value,
- wherein the Mahalanobis spaces are generated in accordance with an inverse matrix of a correlation matrix of the sampled data.
5 more elements
A method of controlling a manufacturing process, comprising:
- setting ideal data of plural manufacturing control parameters of the manufacturing process which includes a plurality of process steps, and a permissible range of the ideal data;
- generating random numbers within the permissible range of the ideal data;
- generating Mahalanobis spaces for each of the plural manufacturing control parameters, based on the random numbers;
- providing sampled data which indicates a sampled data group by sampling the plural manufacturing control parameters at constant time intervals, during the manufacturing process;
- calculating first Mahalanobis distances from the Mahalanobis spaces and the sampled data;
- generating a selected group of combined parameters from the plural manufacturing control parameters;
- calculating second Mahalanobis distances from the Mahalanobis spaces and the selected group of combined parameters;
- and
- determining a degree of incidence of an ideal operating condition for each of the plurality of process steps, in accordance with a degree of divergence between the first and second Mahalanobis distances.
6 more elements
Dependencies are inferred from the claim text.