Patent ID: 6862484
Filing Date: 2005-03-01
Classification: G05B,G06Q,Y02P

Abstract:
1. 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.