Controlled glass manufacturing process

Claim 1

In the manufacture of flat glass comprising portioning, mixing and charging batch materials to a melting furnace; melting said batch materials to form molten glass; refining said molten glass; forming and cooling said molten glass to produce a continuous ribbon of glass; wherein a plurality of servo loops are controlled to control said manufacture of flat glass; the control of each servo loop comprising detecting the value of an individual process parameter to be controlled, comparing the detected value of said process parameter with a standard, responsive to said comparison generating a control signal and responsive to said control signal controlling said process parameter by controlling an actuator acting upon it; said process parameters comprising at least two parameters including batch weight, batch ingredient weights, batch moisture, cullet ratio, glass melter temperature, molten glass level, glass refiner temperature and the like; the improvement comprising: a. establishing for each of said process parameters a plurality of likelihood factors, each related to a general cause of an optical defect, said plurality of causes comprising a glass batch raw material and portioning related cause, a glass furnace thermal condition related cause and a glass furnace refractory and foreign material related cause; b. detecting the location and intensity of an optical defect in said ribbon of glass and responsive thereto generating a signal representing a defect probability factor for each of said plurality of causes; c. comparing each detected process parameter value, as detected at a time when the glass wherein said optical defect is detected passed the point in said manufacture at which said process parameter value is detected, with its standard and responsive thereto generating signals representing its likelihood factors as established in (a); d. iteratively combining each of said signals representing each defect probability factor with each signal representing the likelihood factor corresponding to it for each detected process parameter and thereby generating a signal representing the iterative product of said combining; e. selecting the signal representing the iterative product of said combining which is most disportionate from said signal initially generated in (b); f. comparing said most disportionate signal with a predetermined damping standard and generating a control signal responsive thereto; g. adjusting in response to said control signal the servo loop having the most disportionate likelihood factor signal for said most disportionate iteratively combined defect probability factor signal exceeding said predetermined damping standard wherein the remaining servo loops are permitted to remain unadjusted responsive to said defect probability factor signal whereby said optical defects are substantially reduced.