Patent Publication Number: US-2023150857-A1

Title: Automated Float Glass System

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. patent application Ser. No. 14/925,156, filed Oct. 2, 2015, which claims benefit of U.S. Provisional Application No. 62/074,176, filed Nov. 3, 2014, the disclosures of which are herein incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates generally to the manufacture of float glass and, more particularly, to a float glass system having an automated float bath. 
     Technical Considerations 
     In a float glass process, molten glass from a furnace is poured onto the top of a bath of molten metal located in a float bath. The molten glass forms a continuous glass ribbon. In the float bath, the glass ribbon is sized and cooled. A coating can be applied onto the top surface of the glass ribbon while in the float bath. 
     In a conventional float bath, multiple pairs of opposed top rollers are used to expand and move the glass ribbon through the float bath. The speed of rotation and the tilt angle of the top rollers affect the width and thickness of the glass ribbon. In a conventional float bath, the top rollers are adjusted manually by operators standing beside the float bath. 
     Operation of the float bath in a conventional float glass system is one of the most labor intensive processes in the entire float glass manufacturing process. This is particularly true when changes to the glass ribbon thickness and/or width are desired. At such times, the operators at the float bath are required to work in conjunction with a process control supervisor inside a control room to manually adjust each top roller using mechanical handles and levers. This process is labor, time, and cost intensive. 
     There are also technical problems that must be overcome to adjust the thickness and/or width of the float glass ribbon. For example, synchronizing the individual float bath operators to adjust the position or tilt angle of the top rollers to achieve a desired ribbon width and/or thickness is difficult. Accurately controlling the position or tilt angle of the top roller head is accomplished visually by the operators and, therefore, can vary between operators. Accurately controlling the temperature profile in the float bath, which affects the viscosity of the glass ribbon, is also difficult. 
     Therefore, it would be advantageous to provide a float glass system and/or method that reduces or eliminates at least some of the technical problems discussed above. For example, it would be desirable to provide a system and/or process in which individual operators were not required to adjust the speed and/or tilt of the top rollers manually. For example, it would be desirable if the position and/or tilt angle of the top roller heads could be adjusted more accurately. For example, it would be desirable if the temperature profile inside the float bath and/or the temperature profile of the glass ribbon could be monitored and/or controlled more accurately. For example, it would be desirable if the change from one width and/or thickness of a glass ribbon to a new width and/or thickness could be accomplished in a less labor intensive manner. 
     SUMMARY 
     A float glass system includes a float bath having an entrance end and an exit end. At least one machine vision camera is located to view an interior of the float bath. At least one sensor is connected to the float bath to measure an operating parameter of the float bath. At least one operating device is connected to the float bath. The at least one machine vision camera, the at least one sensor, and the at least one operating device are connected to a control system configured to control the operating device based on input from the at least one machine vision camera and/or the at least one sensor. 
     A method of operating a float glass system comprises providing a float bath having an entrance end and an exit end; locating at least one machine vision camera to view an interior of the float bath; providing at least one sensor connected to the float bath to measure an operating parameter of the float bath; providing at least one operating device connected to the float bath; and connecting the at least one machine vision camera, the at least one sensor, and the at least one operating device to a control system configured to control the at least one operating device based on input from the at least one machine vision camera and/or the at least one sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a plan view illustrating a float glass system incorporating features of the invention; 
         FIG.  2    is a side, sectional view of a float bath of  FIG.  1    along the line II-II in  FIG.  1   ; 
         FIG.  3    is a front view of a top roller and optical device of the invention; 
         FIG.  4    is a side view of the top roller of  FIG.  3   ; 
         FIG.  5    is a plan view of a top roller illustrating a tilt angle of the top roller head; and 
         FIG.  6    is a plan view of a top roller and optical device positioned along an edge of a glass ribbon in a float bath. 
     
    
    
     DESCRIPTION 
     Spatial or directional terms used herein, such as “left”, “right”, “above”, “below”, and the like, relate to the invention as it is shown in the drawing figures. It is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. All numbers used in the specification and claims are to be understood as being modified in all instances by the term “about”. All ranges disclosed herein are to be understood to encompass the beginning and ending range values and any and all subranges subsumed therein. The ranges set forth herein represent the average values over the specified range. 
     The invention comprises, consists of, or consists essentially of, the following aspects of the invention, in any combination. Various aspects of the invention are illustrated in separate drawing figures. However, it is to be understood that this is simply for ease of illustration and discussion. In the practice of the invention, one or more aspects of the invention shown in one drawing figure can be combined with one or more aspects of the invention shown in one or more of the other drawing figures. 
     An exemplary float glass system  10  of the invention utilizes one or more machine vision cameras, one or more sensors, or a combination of machine vision cameras and sensors, to automatically or semi-automatically control the operating parameters of a float bath of the float glass system  10 . The operating parameters can be controlled to achieve a glass ribbon of a desired thickness and/or width. The components of the float glass system  10  will be described and then operation of the float glass system  10  will be described. 
     An exemplary float glass system  10  is shown in  FIG.  1   . The float glass system  10  includes a glass furnace  12  upstream of a float bath  14 . The terms “upstream” and “downstream” used herein refer to the direction of movement of the glass ribbon. The float bath  14  is located upstream of a cooling lehr  16 . A first conveyor  18  extends between the float bath  14  and the lehr  16 . A cutting station  20  is located downstream of the lehr  16 . A second conveyor  22  extends between the lehr  16  and the cutting station  20 . 
     As shown in  FIGS.  1  and  2   , the float bath  14  includes a pool of molten metal  24 , such as molten tin. The float bath  14  has an entrance end  26  adjacent the furnace  12  and an exit end  28  adjacent the first conveyor  18 . In the float glass process, molten glass from the furnace  12  is poured onto the top of the molten metal  24  in the float bath  14 . The molten glass begins to cool and spreads across the top of the molten metal  24  to form a glass ribbon  30 . 
     At least one first cooler  32 , i.e., an entrance cooler, is located downstream of the entrance end  26  of the float bath  14 . The first cooler  32  is an overhead cooler. That is, it is located above the pool of molten metal  24 . The first cooler  32  is in electronic communication with a cooler control device  34 . For example, via a wireless connection or via an electronic cable  36 . The cooler control device  34  includes a temperature sensor that senses the temperature of the first cooler  32 . The cooler control device  34  can adjust the temperature of the first cooler  32 . For example, by increasing or decreasing the flow of cooling fluid to the first cooler  32 . The first cooler  32  affects the temperature in the headspace of the float bath  14 . Decreasing the temperature in the headspace helps to cool the molten glass to increase the viscosity of the molten glass to begin forming the more viscous glass ribbon  30 . While only one first cooler  32  is illustrated, it is to be understood that additional such coolers could be located at various locations within the float bath  14 . 
     The cooler control device  34  is in electronic communication with a control system  40 . For example, via a wireless connection or via an electronic cable  42 . The control system  40  includes a conventional computer with a storage device, such as a hard drive. The control system  40  includes a database of operating parameters for the float bath  14 , as discussed below. The database can be an electronic database maintained on a conventional computer system having a conventional memory device and conventional input and output devices. A conventional computer system includes a central processing unit (CPU) in electronic communication with a data storage device, such as a hard drive, optical disk, and the like for storing the database. The CPU may also be in electronic communication with one or more of a read only memory (ROM) which stores CPU program instructions, a random access memory (RAM) for temporary data storage, and a clock for providing time signals to the CPU. The input/output device is connected to the CPU and may be of any conventional type, such as a monitor and keyboard, mouse, touchscreen, printer, voice activated, etc. The computer system runs appropriate custom-designed or conventional software to perform the steps of the invention. The specific hardware, firmware and/or software utilized in the system need not be of a specific type but may be any such conventionally available items designed to perform the method or functions of the present invention. Exemplary computer systems are disclosed in U.S. Pat. Nos. 5,794,207; 5,884,272; 5,797,127; 5,504,674; 5,862,223; and 5,432,904. 
     At least one air temperature sensor  44  is located in the headspace of the float bath  14  above the molten metal  24 . The air temperature sensor  44  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable  46 . The air temperature sensor  44  monitors the temperature in the headspace of the float bath  14 . While only one air temperature sensor  44  is illustrated, it is to be understood that additional such sensors could be located at various locations within the float bath  14 . 
     At least one bath temperature sensor  48  is detects the temperature of the molten metal  24 . The bath temperature sensor  48  is connected to the control system  40  in any conventional method. For example, via a wireless connection or by an electronic cable. While only one bath temperature sensor  48  is illustrated, it is to be understood that additional such sensors could be located at various locations within the float bath  14 . 
     At least one machine vision camera is located adjacent the entrance end  26  of the float bath  14 . The at least one machine vision camera is part of a machine vision system, as described in more detail below. In the example shown in  FIG.  1   , a first machine vision camera  50  is positioned to view one lateral side of the interior of the float bath  14  and a second machine vision camera  52  is positioned to view the opposed lateral side of the float bath interior. The machine vision cameras  50 ,  52  can be located outside of the float bath  14  and aligned with windows in the float bath  14 . Or, the first and second machine vision cameras  50 ,  52  can be located in housings in the float bath  14 . The first and second machine vision cameras  50 ,  52  are positioned to view the glass ribbon  30  at or near the entrance end  26  of the float bath  14 . The first camera  50  and second camera  52  are in electronic communication with the control system  40  in any conventional manner. For example, via wireless connection or by electronic cables  54  and  56 . The machine vision software for the machine vision cameras can be stored in the control system  40 . 
     A plurality of opposed sets of roller assemblies  60  are located along the sides of the float bath  14  and extend into the interior of the float bath  14 . The roller assemblies  60  include a top roller  62  having a shaft or barrel  64  connected to a rotatable head  66 . As shown in  FIGS.  3  and  4   , the head  66  includes a plurality of circumferential teeth  68  configured to grip the float ribbon  30 . Rotation of the roller assembly heads  66  pulls the float ribbon  30  along the top of the molten metal  24 . The speed of rotation of the heads  66  affects the thickness of the glass ribbon  30 . The faster the speed of rotation, all other parameters remaining the same, the thinner will be the glass ribbon  30 . The angle (or tilt) of the heads  66  can affect the width of the glass ribbon  30 . For example, angling the heads  66  outwardly increases the width of the glass ribbon  30 . Angling the heads  66  inwardly decreases the width of the glass ribbon  30 . This angling of the heads  66  also can affect the thickness of the glass ribbon  30 . The float bath  14  can include 4 to 10 pairs of opposed roller assemblies  60 , for example 5 to 9 pairs, for example 7 pairs. 
     The top rollers  62  include a movement device  70 , such as a servo mechanism, that controls the speed of rotation of the head  66 , the tilt angle of the head  66 , and the depth of the head  66  in the glass ribbon  30  (i.e., the bite). The movement device  70  is connected to a controller  72 . For example, via a wireless connection or by an electronic cable. The controller  72  is an electronic communication with the control system  40 . For example, via a wireless connection or by an electronic cable. 
     As illustrated in  FIG.  5   , by “tilt angle” of the roller assembly head  66  is meant the angle  57  formed between a line  58  parallel to a centerline CL of the float bath  14  and a line  59  extending through the head  66  (i.e., indicating the direction the head  66  is pointing). If the head  66  is directed towards the adjacent wall of the float bath  14  (i.e., is pointed outwardly), this stretches and widens the float glass ribbon  30 . If the head  66  is directed inwardly (away from the adjacent wall of the float bath  14 ), this decreases the width of the float glass ribbon  30 . 
     The roller assembly  60  can include an optical device, such as a periscope  74 . The periscope  74  extends into the interior of the float bath  14  and is positioned to view the head  66  of the top roller  62 . A roller assembly machine vision camera  76  can be positioned to view through the periscope  74 . The camera  76  is connected to the control system  40 . For example, via a wireless connection 9 by an electronic cable. As described below, the periscope  74  can also be positioned to view a lateral edge of the float glass ribbon  30 . 
     Alternatively, an exterior machine vision camera  78  can be associated with the roller assembly  60  and can be positioned to view the interior of the float bath  14  through a window  80  in the side of the float bath  14 . The exterior camera  78  can be connected to the control assembly  40 . For example, via a wireless connection or by an electronic cable. The exterior machine vision camera  78  can be positioned to view a lateral edge of the float glass ribbon  30 . 
     A plurality of heating coils  82  are positioned in the interior of the float bath  14 . These heating coils  82  can be attached to the top of the float bath  14  and can extend downwardly above the level of the glass ribbon  30 . The heating coils  82  are connected to a control device  84 . For example, via a wireless connection or by an electronic cable. The control device  84  senses and controls the temperature of the heating coils  82 . The control device  84  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable. 
     A plurality of bath coolers  86  are located in the float bath  14 . For example, downstream of the heating coils  82 . For example, the coolers  86  can be pipe coolers extending into the molten metal  24 . The coolers  86  are connected to a control device  88 . For example, via a wireless connection or by an electronic cable. The control device  88  senses and controls the temperature of the coolers  86 . The control device  88  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable. 
     At least one thickness sensor  90  is located adjacent the exit end  28  of the float bath  14 . The thickness sensor  90  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable. The thickness sensor  90  can be, for example, an optical thickness scanner, a machine vision camera, or any conventional thickness measuring device. The thickness sensor  90  measures the thickness of the glass ribbon  30  at or adjacent the exit end  28  of the float bath. The thickness sensor  90  can be located outside of the exit end  28  of the float bath  14 . Alternatively, the thickness sensor  90  can be located inside of the float bath  14 . 
     At least one exit machine vision camera  92  is positioned at or adjacent the exit end  28  of the float bath  14 . The exit camera  92  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable. The exit machine vision camera  92  can be located inside the float bath  14 . Alternatively, the exit machine vision camera  92  can be located outside of the exit end  28  of the float bath  14 . 
     A display and input device  94  is located in a control booth  96  and is connected to the control system  40 . The display and input device  94  can be a conventional computer monitor and a keyboard. 
     One or more glass ribbon temperature sensors  98  are positioned in the float bath  14  to measure the temperature of the glass ribbon  30  at various locations.  FIGS.  1  and  2    show a glass ribbon temperature sensor  98  positioned adjacent the exit end  28  of the float bath  14 . The glass ribbon temperature sensor  98  can be a conventional thermal or optical temperature sensor. The glass ribbon temperature sensor  98  is connected to the control system  40 . For example, via a wireless connection or by an electronic cable. 
     An exemplary operation of the float glass system  10  will now be described. 
     Molten glass is poured onto the molten metal  24  at the entrance end  26  of the float bath  14 . Initial cooling by the first cooler  32  increases the viscosity of the molten glass to form the glass ribbon  30 . The top roller heads  66  engage the top of the glass ribbon  30  to move, e.g., pull, the glass ribbon  30  along the top of the molten metal  24  and through the float bath  14 . The speed of rotation of the heads  66  affects the speed of the glass ribbon  30  through the float bath. Generally, the higher the speed of rotation of the heads  66 , the thinner will be the glass ribbon  30 . The tilt angle of the heads  66  affects the width of the ribbon  30  (which can also affect the glass ribbon thickness). If the heads  66  are angled outwardly, this increases the width of the glass ribbon  30  (and can also decrease the thickness of the glass ribbon  30 ). The barrel position and/or length, head angle, head speed, and bite of the top roller  62  are controlled by the controller  72  connected to the movement device  70  of the roller assembly  60 . 
     The heating coils  82  affect the temperature in the headspace of the float bath  14 . The bath coolers  86  affect the temperature of the molten metal  24 . These both can affect the viscosity of the glass ribbon  30 , which can affect the thickness and/or the width of the glass ribbon  30 . Generally, the higher the temperature inside the float bath  14 , the thinner and wider will be the glass ribbon  30 . 
     In the past, operating parameters of a conventional float bath were manually set and adjusted by the float bath operators to obtain a desired glass ribbon width and thickness. Examples of these operating parameters include, for example, the barrel position, head angle, head speed of rotation, and bite of the roller assemblies; and/or the temperature in the headspace; and/or the temperature of the molten metal, were manually set and adjusted by the float bath operators to obtain a desired glass ribbon width and thickness. 
     However, operating parameters of the float bath  14  of the invention can be set or adjusted automatically or semi-automatically. By “automatically” is meant without the need for operator or supervisor approval. By “semi-automatically” is meant that operator or supervisor approval is required before one or more operating parameters of the float bath  14  are changed by the control system  40 . 
     For example, various “recipes” of float bath operating parameters to achieve a desired thickness and/or width of a glass ribbon of a particular composition are stored in the control system  40 . For example, these recipes can be stored on the hard drive of the computer. The recipes can be determined, for example, by prior manual settings of the float bath operating parameters determined over time to provide a glass ribbon of a particular width and/or thickness. The control system  40  can also include the machine vision software to provide the image processing for the machine vision cameras associated with the float bath  14 . Exemplary machine vision cameras and machine vision software are available from Cognex Corporation, Banner Engineering, and Microscan systems Inc. 
     Current operating parameters of the float bath  14  are supplied to the control system  40  by the various sensors located in the float bath  14 . For example, the temperature in the head space of the float bath  14  at various locations is supplied by the air temperature sensors  44 . The temperature of the glass ribbon  30  at various locations is supplied by the glass ribbon temperature sensors  98 . The barrel position, head speed, head angle, and bite are supplied by the controllers  72  of the roller assemblies  60 . The temperature of the molten metal  24  is supplied by the bath temperature sensors  48 . The thickness of the glass ribbon  30  is supplied by the thickness sensors  90 . These operating parameters are automatically updated into the control system  40  by the various sensors. For example, the operating parameters can be updated in the range of every 1 second to 60 seconds, particularly every 1 second to 10 seconds, more particularly every 1 to 2 seconds. 
     The machine vision cameras can be used to monitor and/or adjust the width and/or thickness of the glass ribbon  30 . The first machine vision camera  50  and second machine vision camera  52  provide an image of the lateral edges of the glass ribbon  30  adjacent the entrance end  26  of the float bath  14 . These images are supplied to the control system  40  and are processed via the machine vision image processing software to provide a machine vision position of the left and right lateral edges of the glass ribbon  30 , which defines a width of the glass ribbon  30  adjacent the entrance end  26  of the float bath  14 . 
     The roller assembly machine vision camera  76  (or the exterior machine vision camera  78 ) associated with the roller assemblies  60  provides a machine vision location of the lateral edge of the glass ribbon  30  and the distance of the head  66  from the lateral edge of the glass ribbon  30 . 
     The exit cameras  92  provide a machine vision image of the lateral edges of the glass ribbon  30  adjacent the exit end  28  of the float bath  14 , which define the width of the glass ribbon  30  adjacent the exit end  28  of the float bath  14 . 
     An operator in the control booth  96  can view or monitor the current operating parameters of the float bath  14  from the data supplied by the various sensors in the float bath  14 . The operator can monitor or view the width and/or thickness of the glass ribbon  30  determined from the machine vision system. For example, this data can be displayed on a computer screen. 
     When it is desired to change the width and/or thickness of the glass ribbon  30 , the operating parameters of the float bath  14  to achieve the desired width and/or thickness can be set or adjusted by the operator in the control booth  96  utilizing the control system  40  without the need for manual adjustment by personnel stationed adjacent the float bath  14 . 
     Various recipes (float bath operating parameters to provide a glass ribbon  30  of a predetermined width and/or thickness) or programs are stored in the control system  40 . For example, parameters such as head speed, head angle, barrel position, bite, glass temperature, molten metal temperature, and/or headspace temperature, can be stored in the hard drive of the control system  40 . These recipes can be determined based on the manual settings of the float bath used in the past to achieve a glass ribbon  30  of a particular width and/or thickness. 
     The operator can adjust one or more of the operating parameters by inputting new parameters into the control system  40  via the input device  94 . These new parameters can be listed in a recipe stored in the control system  40  for a glass composition and selected to provide a glass ribbon  30  having a particular width and/or thickness. The control system  40  then electronically adjusts the float bath operating parameters, for example, head speed, head angle, and headspace temperature, as directed, to change these operating parameters. The operator can monitor the effect of these changes on the thickness and/or width of the glass ribbon  30  by the signals from the thickness scanners  90  and the machine vision exit cameras  92 . The operator can make adjustments to one or more of the operating parameters to achieve the desired width and/or thickness. 
     Alternatively, the width and/or thickness of the glass ribbon  30  can be automatically adjusted or changed by the control system  40 . For example, by automatically adjusting the thermal conditions inside the float bath  14  and/or the operating parameters of the roller assemblies  42  to provide a glass ribbon  28  of a predetermined thickness and/or width. 
     The operating parameters of the float bath  14  are obtained and automatically updated in the computer system  40  via the sensors and machine vision cameras located in and around the float bath  14 . For example, the current values of the head speed, head angle, barrel distance into the metal bath, and depth of the head in the glass ribbon (bite), can be transmitted to the control system  40  and stored in a matrix (current values matrix). These current values can be updated frequently, for example, every 1 to 60 seconds, such as every 1 to 10 seconds, such as every 1 to 2 seconds. Thus, the current operating parameters are constantly updated and stored in the control system  40 . The width of the glass ribbon  30  at the exit end  28  of the float bath  14  can be provided and updated by the exit machine vision cameras  92  in conjunction with the machine vision software stored on the control system  40 . 
     In order to change the width and/or thickness of the glass ribbon  30 , a recipe, i.e., a final target matrix (final values matrix) of the float bath operating parameters to achieve a desired width and/or thickness is selected from the recipes stored in the control system  40 . The current values matrix reflects the current operating parameters of the float bath  14 . The final values matrix reflects the desired new operating parameters to achieve a glass ribbon of a desired width and/or thickness. To achieve a smooth transition from the current operating parameters to the new final operating parameters, the control system  40  may also include a step change matrix defining the magnitude of changes to specific operating parameters within a specific period of time, and a time parameter to complete the change from the current operating parameters to the new final operating parameters. 
     Similar current, final, and step change matrices can be developed and stored for other operating parameters of the float bath, such as headspace temperature, bath temperature, etc. 
     The control system  40  can be programmed such that the change from the current operating parameters to the final operating parameters occurs automatically, e.g., once the operator in the control booth  96  selects a recipe from the storage device of the control system  40  (e.g., using the input device  94 ), the control system  40  makes the necessary changes in the operating parameters of the float bath  14  without any additional input from the operator. Alternatively, the change can occur semi-automatically, which means that after the desired recipe is selected, the control system requires the operator to input confirmation at one or more points during the change to continue adjusting the float bath operating parameters. Without this input, the control system  40  will not continue changing the operating parameters. 
     By way of illustration, an exemplary current values matrix (the current operating parameters of the float bath  14 ) includes a head speed of 20 rotations per minute (rpm), a tilt angle of 20 degrees outward, a barrel distance of 1 meter, a bite of 1 centimeter, and a headspace temperature of 640 degrees Centigrade to provide a glass ribbon  30  having a width of 15 meters and a thickness of 1.8 millimeters (mm). Such a thickness is typical for producing automotive glass. 
     However, if it is desired to start making architectural glass, for example, having a width of 10 meters and a thickness of  12  mm, the control operator searches the database of the control system  40  for the operating parameters (the final values matrix) to provide the desired width and thickness. For example, assuming the final values matrix is a head speed of 10 rpm, a tilt angle of 5 degrees inward, a barrel distance of 2 meter, a bite of 1.5 centimeter, and a headspace temperature of 550 degrees Centigrade, in automatic mode, the operator can select the final values matrix. The control system  40  automatically reduces the head speed, decreases the tilt angle, extends the barrel, depresses the head into the glass ribbon, and decreases the headspace temperature (for example, by increasing coolant flow to the coolers  32  and/or reducing the temperature of the heating coils  82 ). The operator can monitor the change in the operating parameters (as provided by the various in bath sensors) and also the effect on the width of the glass ribbon  30  (via the exit machine vision camera  92 ) and on the thickness of the glass ribbon  30  (via the thickness sensor  90 ). 
     The step change matrix can determine the rate of change of the operating parameters from the current values to the desired final values. For example, the step change matrix can limit the change of one or more operating parameters to not greater than a predetermined amount per unit of time. For example, not allowing a change of greater than 20 percent of the current values matrix (which is continuously updated during the changeover) per 10 minutes. This allows a smooth transition to the new operating parameters. 
     In addition to width and/or thickness of the glass ribbon  30 , the roller assemblies  60  and control system  40  can be used to provide trim control. By “trim control” is meant the width of the glass ribbon  30  outboard of the heads  66 . This edge portion of the glass ribbon  30  is typically trimmed off and either recycled or discarded. As shown in  FIGS.  3  to  5   , the periscope  74  and associated machine vision camera  76  can be used to view the distance  106  from the head  66  to the edge  108  of the glass ribbon  30 . This distance  106  can be controlled by the operator in the control booth  96  by adjusting the position of the head  66  with respect to the edge  108  of the glass ribbon  30 . Alternatively, this distance  106  can be controlled automatically by the control system  40  by adjusting the position of the head  66  based on the distance  106  determined by the machine vision camera  76  and associated software to achieve a desired trim. 
     The invention can be described further by the following numbered clauses: 
     Clause 1: A float glass system  10  comprising a float bath  14  having an entrance end  26  and an exit end  28 . The float bath  14  includes at least one glass ribbon thickness sensor  90  to determine a thickness of a glass ribbon  30  and at least one machine vision camera  50 ,  52 ,  76 ,  92  to determine a width of the glass ribbon  30 . The at least one thickness sensor  90  and at least one machine vision camera  50 ,  52 ,  76 ,  92  are connected to a control system  40 . The control system  40  includes a plurality of float bath operating parameters to obtain a glass ribbon  30  of a desired width and/or thickness. 
     Clause 2: The float glass system  10  of clause 1, including at least one first cooler  32  located downstream of the entrance end  26  of the float bath  14 . The first cooler  32  is operatively connected to the control system  40 . 
     Clause 3: The float glass system  10  of clauses 1 or 2, including at least one air temperature sensor  44  located in the headspace of the float bath  14  and operatively connected to the control system  40 . 
     Clause 4: The float glass system  10  of any of clauses 1 to 3, including at least one bath temperature sensor  48  located in the float bath and operatively connected to the control system  40 . 
     Clause 5: The float glass system  10  of any of clauses 1 to 4, including at least one machine vision camera located adjacent the entrance end  26  of the float bath  14  and operatively connected to the control system  40 . 
     Clause 6: The float glass system  10  of any of clauses 1 to 5, including a first machine vision camera  50  positioned to view one lateral side of the interior of the float bath  14  and a second machine vision camera  52  positioned to view the opposed lateral side of the float bath interior. 
     Clause 7: The float glass system  10  of any of clauses 1 to 6, including a plurality of opposed sets of roller assemblies  60  located along the sides of the float bath  14  and extending into the interior of the float bath  14  and operatively connected to the control system  40 . 
     Clause 8: The float glass system  10  of clause 7, wherein the roller assemblies  60  include a top roller  62  having a barrel  64  connected to a rotatable and/or pivotable head  66 . 
     Clause 9: The float glass system  10  of clauses 7 or 8, wherein the roller assemblies  60  include an optical device, such as a periscope  74 , extending into the interior of the float bath  14  and positioned to view the head  66  of the top roller  62 . 
     Clause 10: The float glass system  10  of clause 9, including a roller assembly machine vision camera  76  positioned to view through the periscope  74 , wherein the roller assembly machine vision camera  76  is operatively connected to the control system  40 . 
     Clause 11: The float glass system  10  of clauses 7 or 8, including an exterior machine vision camera  78  associated with the roller assembly  60  and positioned to view the interior of the float bath  14  through a window  80  in the side of the float bath  14 , wherein the exterior camera  78  is operatively connected to the control assembly  40 . 
     Clause 12: The float glass system  10  of any of clauses 1 to 11, including a plurality of heating coils  82  positioned in the interior of the float bath  14 , wherein the heating coils  82  are operatively connected to the control system  40 . 
     Clause 13: The float glass system  10  of any of clauses 1 to 12, including at least one bath cooler  86  located in the float bath  14  and operatively connected to the control system  40 . 
     Clause 14: The float glass system  10  of any of clauses 1 to 13, wherein the at least one thickness sensor  90  is located adjacent the exit end  28  of the float bath  14 . 
     Clause 15: The float glass system  10  of any of clauses 1 to 14, including at least one exit machine vision camera  92  positioned at or adjacent the exit end  28  of the float bath  14  and operatively connected to the control system  40 . 
     Clause 16: The float glass system  10  of any of clauses 1 to 15, including a display and input device  94  connected to the control system  40 . 
     Clause 17: The float glass system  10  of any of clauses 1 to 16, including one or more glass ribbon temperature sensors  98  positioned in the float bath  14  and operatively connected to the control system  40 . 
     Clause 18: A method of operating a float bath  14  of a float glass system  10 , comprising: storing a plurality of “recipes” of float bath operating parameters to achieve a desired thickness and/or width of a glass ribbon  30  in a control system  40 ; determining a matrix of current float bath operating parameters (current matrix); selecting a recipe of float bath operating parameters defining a matrix of desired operating parameters to achieve a width and/or thickness of the glass ribbon  30  (final matrix); and adjusting the operating parameters of the float bath  14  to the desired operating parameters. 
     Clause 19: The method of clause 18, wherein the recipes are determined by prior manual settings of the float bath operating parameters determined to provide a glass ribbon of a particular width and/or thickness. 
     Clause 20: The method of clauses 18 or 19, wherein the control system  40  includes machine vision software for machine vision cameras associated with the float bath  14 . 
     Clause 21: The method of any of clauses 18 to 20, wherein current operating parameters of the float bath  14  are supplied to the control system  40  by sensors located in the float bath  14 . 
     Clause 22: The method of any of clauses 18 to 21, wherein the operating parameters include at least one of a temperature in the head space of the float bath  14 , a temperature of the glass ribbon  30 , a barrel position, a head speed, a head angle, and a bite of a roller assembly  60 , a temperature of molten metal  24  in the float bath  14 , a thickness of the glass ribbon  30 , and a width of the glass ribbon. 
     Clause 23: The method of any of clauses 18 to 22, wherein the operating parameters are automatically updated in the control system  40 . 
     Clause 24: The method of any of clauses 18 to 23, wherein the operating parameters are updated in the range of every 1 second to 60 seconds, particularly every 1 second to 10 seconds, more particularly every 1 to 2 seconds. 
     Clause 25: The method of any of clauses 18 to 24, including at least one machine vision camera  50 ,  52 ,  78 ,  92  to monitor and/or adjust the width and/or thickness of the glass ribbon  30 . 
     Clause 26: The method of any of clauses 18 to 25, including a first machine vision camera  50  and a second machine vision camera  52  adjacent an entrance end  26  of the float bath  14  to provide a width of the glass ribbon  30  adjacent the entrance end  26  of the float bath  14 . 
     Clause 27: The method of any of clauses 18 to 26, including a roller assembly machine vision camera  76  or an exterior machine vision camera  78  associated with a roller assembly  60  of the float bath  14  to provide a distance of a roller assembly head  66  from a lateral edge of the glass ribbon  30 . 
     Clause 28: The method of any of clauses 18 to 27, including at least one exit camera  92  adjacent the exit end  28  of the float bath  14  to provide the width of the glass ribbon  30  adjacent the exit end  28  of the float bath  14 . 
     Clause 29: The method of any of clauses 18 to 28, including selecting a step change matrix defining the magnitude of changes to specific operating parameters within a specific period of time to adjust from the current operating parameters to the final operating parameters. 
     Clause 30: The method of any of clauses 18 to 29, wherein the control system  40  changes the operating parameters from the current operating parameters to the final operating parameters once a recipe is selected without additional input from an operator. 
     Clause 31: The method of any of clauses 18 to 29, wherein after the desired recipe is selected, the control system 40  requires at least one input confirmation to continue adjusting the float bath operating parameters at one or more points during the change. 
     Clause 32: The method of any of clauses 18 to 31, wherein the control system  40  adjusts the width of the glass ribbon  30  outboard of the heads  66  of the roller assemblies  60  by the machine vision camera  76  and associated software to achieve a desired trim. 
     It will be readily appreciated by those skilled in the art that modifications, as indicated above, may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof.