Process control using multiple detections

Abstract

Methods of controlling manufacturing processes manufacturing, for example, absorbent articles. A target parameter to be measured is established, as are acceptable conditions of the target parameter. The target parameter is detected with first and second replications of determinations of the condition of the goods using multiple independent determinors, for example multiple sensors, or multiple replications using a common determinator, for example software instructions for analyzing a full digital vision image. Multiple determinations are taken at sites which are selected for their prospects for indicating acceptable conditions of the parameter. The method includes developing a measurement strategy, programming a computer to use appropriate analysis tools to evaluate the determination signals, transmitting the signals to the computer, and processing the signals according to an appropriate method. A given parameter can be inspected at respective duplicative sites, at spaced sites or multiple times at the same site. The parameter can be detected using three or more replications of the condition of the goods, optionally including processing signals from respective first and second parameters according to two or more different analytical methods. Averaging may or may not be an appropriate analytical method. The inspection system can compensate for various types of erroneous otherwise inappropriate signals and develop a corresponding response to respective process control devices. First and second replications can be taken at a common work station, or at spaced work stations. Preferably, the method measures parameters on every unit of goods fabricated or otherwise manipulated on the manufacturing line.