JP2022549117A - Method and apparatus for forming glass ribbon - Google Patents

Abstract

A method for shaping a glass ribbon may include moving the glass ribbon along a travel path in a travel direction at a predetermined ribbon velocity. The method may include engaging the glass ribbon with an end effector attached to a robotic arm. The method may include moving the end effector in the direction of travel at a first robot speed. The method may include detecting a force exerted by the glass ribbon on the end effector. The method may include changing the speed of the end effector from the first robot speed to the second robot speed when the magnitude of the force exceeds a predetermined value.

Description

Related application

This application claims the benefit of priority under 35 U.S.C. are incorporated herein by reference.

TECHNICAL FIELD The present disclosure relates generally to methods for forming glass ribbons and, more particularly, to methods for forming glass ribbons with a glass manufacturing apparatus having a control assembly.

It is known to produce glass ribbons from molten material by means of glass production equipment. Occasionally, contact with the glass ribbon can damage the glass ribbon. An end effector may engage the glass ribbon to limit damage. However, matching the speed and travel path of the end effector to the glass ribbon can be difficult.

SUMMARY The following presents a simplified summary of the disclosure in order to provide a basic understanding of some of the embodiments described in the Detailed Description.

In some embodiments, the glass making apparatus includes one or more devices that facilitate reducing relative motion between the glass ribbon and the end effector. For example, the end effector may engage the glass ribbon and travel with it in the direction of travel. The end effector may be connected to a sensor that can detect any force exerted by the glass ribbon on the end effector. A control assembly may be electrically connected to the sensor and a robotic arm that controls the movement of the end effector. The control assembly can receive force data from the sensors and adjust the speed and/or path of the end effector to more closely match the speed and/or path of the glass ribbon. Therefore, relative motion between the glass ribbon and the end effector can be reduced, thereby reducing any force applied to the glass ribbon.

According to some embodiments, a method for shaping a glass ribbon includes moving the glass ribbon along a travel path in a travel direction at a predetermined ribbon speed. The method includes engaging a glass ribbon with an end effector attached to a robotic arm. The method includes moving the end effector in a direction of travel at a first robot speed. The method includes detecting a force exerted by the glass ribbon on the end effector. The method includes changing the speed of the end effector from a first robot speed to a second robot speed when the magnitude of the force exceeds a predetermined value.

In some embodiments, the method includes separating the first ribbon portion of the glass ribbon from the second ribbon portion of the glass ribbon prior to varying the speed.

In some embodiments, the method includes engaging a second ribbon portion of the glass ribbon prior to changing the speed.

In some embodiments, the method reduces the speed of the end effector during the period from engaging the end effector with the first ribbon portion to separating the first ribbon portion from the second ribbon portion. at a first robot speed.

In some embodiments, force is detected at multiple locations.

According to some embodiments, a method for shaping a glass ribbon includes moving the glass ribbon in a travel direction along a travel path. The method includes engaging a first ribbon portion of a glass ribbon with an end effector attached to a robotic arm. The method includes moving the end effector during a first cycle of operation during the steps of engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion of the glass ribbon. Moving at a first robot speed in the direction of travel. The method includes detecting a first force exerted by the first ribbon portion on the end effector during a first cycle of operation. The method includes engaging the end effector with the second ribbon portion after the first cycle of operation. The method includes varying the velocity of the end effector from a first robot velocity to a second robot velocity and moving the end effector at the second robot velocity in a heading direction based on the first force during a second motion cycle. including the step of moving to

In some embodiments, the method includes separating the first ribbon portion from the second ribbon portion prior to engaging the second ribbon portion.

In some embodiments, the method includes detecting a second force exerted by the second ribbon portion on the end effector during a second cycle of operation. The method includes engaging the end effector with a third ribbon portion of the glass ribbon after the second cycle of operation. The method includes varying the speed of the end effector from a second robot speed to a third robot speed based on one or more of the first force or the second force during a third motion cycle; There is the step of moving the end effector forward at a third robot speed.

In some embodiments, the method comprises a first cycle of operation during the steps of engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion. maintaining the speed of the end effector at the first robot speed through.

In some embodiments, the method includes separating the second ribbon portion from the third ribbon portion prior to engaging the third ribbon portion.

In some embodiments, the method includes a second cycle of operation during the steps of engaging the second ribbon portion with the end effector and separating the second ribbon portion from the third ribbon portion. maintaining the speed of the end effector at the second robot speed through.

In some embodiments, the first force is detected at multiple locations.

In some embodiments, changing the speed occurs when the first force magnitude exceeds a predetermined value.

In some embodiments, the speed of the end effector is changed to a second robot speed before beginning the second motion cycle.

According to some embodiments, a method for shaping a glass ribbon includes moving the glass ribbon along a travel path in a travel direction at a predetermined ribbon speed. The method includes engaging a first ribbon portion of a glass ribbon with an end effector attached to a robotic arm. The method includes moving the end effector in a direction of travel at a predetermined robot velocity. The method includes detecting a force exerted by the first ribbon portion on the end effector. The method includes quantifying the ribbon velocity by correlating the ribbon velocity to the robot velocity when the force magnitude is within a predetermined range of values. The method includes adjusting parameters of the glass ribbon based on the ribbon speed.

In some embodiments, quantifying the ribbon velocity comprises engaging the first ribbon portion with the end effector to separating the first ribbon portion from the second ribbon portion of the glass ribbon. Determining the average ribbon velocity during the period.

In some embodiments, adjusting the parameters includes maintaining constant lengths of the first ribbon portion and the second ribbon portion.

In some embodiments, quantifying ribbon velocity includes determining an instantaneous ribbon velocity during a sampling period that is less than about 2 milliseconds.

Additional features and advantages of the embodiments disclosed herein will be set forth in, and in part will be apparent to those skilled in the art from, the following detailed description, or in the claims that follow. recognized by practicing the embodiments described herein, including the scope and accompanying drawings. It should be appreciated that both the foregoing general description and the following detailed description present embodiments intended to provide an overview or framework for understanding the nature and features of the embodiments disclosed herein. . The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the disclosure and, together with the description, explain their principles and operation.

These and other features, embodiments and advantages will become better understood upon reading the following detailed description with reference to the accompanying drawings.
1 is a schematic diagram of an exemplary embodiment of a glass manufacturing apparatus according to embodiments of the present disclosure; FIG. 2 is a perspective cross-sectional view of the glass manufacturing apparatus according to an embodiment of the present disclosure, taken along line 2-2 of FIG. 1; FIG. 2 is a partially enlarged view of a glass manufacturing apparatus according to an embodiment of the present disclosure, in area 3 of FIG. 1; FIG. 4 is a side view of the glass making apparatus according to an embodiment of the present disclosure including an end effector, taken along line 4-4 of FIG. 3; FIG. 5 is a side view of a glass manufacturing apparatus similar to FIG. 4 and according to an embodiment of the present disclosure with end effectors engaged with a glass ribbon; FIG. 6 is a side view of a glass manufacturing apparatus according to an embodiment of the present disclosure, similar to FIG. 5, with the first ribbon portion separated; FIG. FIG. 7 is a side view of a glass making apparatus according to an embodiment of the present disclosure, similar to FIG. 6, with the first ribbon portion separated from the second ribbon portion; 8 is a side view of a glass making apparatus according to an embodiment of the present disclosure, similar to FIG. 7, with an end effector engaged with a second ribbon portion; FIG. FIG. 9 is a side view of a glass making apparatus according to an embodiment of the present disclosure, similar to FIG. 8, with an end effector separating a second ribbon portion from a third ribbon portion; 10 is a side view of the glass making apparatus similar to FIG. 9 with the end effector engaging the third ribbon portion of the glass ribbon after the second cycle of operation; FIG. 1 is a control diagram of a glass manufacturing apparatus according to an embodiment of the present disclosure; FIG. FIG. 10 shows a plot of time versus force applied to an end effector by a glass ribbon, in accordance with an embodiment of the present disclosure;

These embodiments are described in more detail below with reference to the accompanying drawings, which show several exemplary embodiments. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

The present disclosure relates to glass manufacturing equipment and methods for forming glass ribbons. For the purposes of this application, "glass ribbon" is defined as a glass ribbon in a viscous state, a glass ribbon in an elastic state (e.g. at room temperature) and/or a glass ribbon in a viscoelastic state between a viscous and elastic state. Think more than one of us. Methods and apparatus for forming glass ribbons are described below by way of exemplary embodiments for producing glass ribbons. As shown schematically in FIG. 1, in some embodiments, an exemplary glass making apparatus 100 includes a glass melting and feeding apparatus 102 and a quantity of molten material 121 to form a glass ribbon, eg, a glass ribbon. and a molding apparatus 101 with a molding container 140 designed to produce 103 . In some embodiments, the glass ribbon 103 is positioned between opposite edge portions (eg, edge beads) formed along a first outer edge 153 and a second outer edge 155 of the glass ribbon 103. A central portion 152 may be provided. In this case, the thickness of the edge portions may be greater than the thickness of the central portion. Additionally, in some embodiments, the separated glass ribbon 104 is separated from the glass ribbon 103 by a glass separator 149 (e.g., scribe, creasing wheel, diamond tip, laser, etc.) along the separation path 151. may be

In some embodiments, glass melting and feeding apparatus 102 may include melting vessel 105 positioned to receive batch material 107 from holding bin 109 . Batch material 107 may be introduced by batch feeder 111 operated by motor 113 . In some embodiments, optional controller 115 is activated to activate motor 113 to introduce a desired amount of batch material 107 into melting vessel 105, as indicated by arrow 117. you can Melting vessel 105 may heat batch material 107 to provide molten material 121 . In some embodiments, a melt probe 119 may be used to measure the level of molten material 121 inside standpipe 123 and communicate the measured information to controller 115 via communication line 125 . can do.

Additionally, in some embodiments, the glass melting and feeding apparatus 102 may include a first conditioning station located downstream of the melting vessel 105 and It comprises a finer vessel 127 connected to the melting vessel 105 via a first connecting conduit 129 . In some embodiments, melt material 121 may be gravity fed from melt vessel 105 to finer vessel 127 via first connecting conduit 129 . For example, in some embodiments, gravity may move molten material 121 from melting vessel 105 through the internal passageway of first connecting conduit 129 to finening vessel 127 . Additionally, in some embodiments, air bubbles may be removed from the molten material 121 inside the finer vessel 127 by various techniques.

In some embodiments, the glass melting and feeding apparatus 102 may further comprise a second conditioning station, which may be located downstream of the finer vessel 127. A chamber 131 is provided. This mixing chamber 131 may be used to provide a homogeneous composition of the molten material 121, which may reduce or eliminate inhomogeneities. Otherwise, this inhomogeneity may exist within the molten material 121 exiting the finer vessel 127 . As shown, the finer vessel 127 may be connected to the mixing chamber 131 via a second connecting conduit 135 . In some embodiments, molten material 121 may be gravity fed from finer vessel 127 to mixing chamber 131 via second connecting conduit 135 . For example, in some embodiments, gravity may move molten material 121 from finer vessel 127 through the internal passageway of second connecting conduit 135 and into mixing chamber 131 .

Additionally, in some embodiments, the glass melting and feeding apparatus 102 may include a third conditioning station located downstream of the mixing chamber 131 . It has a feed chamber 133 which may be used. In some embodiments, the feed chamber 133 may condition the molten material 121 for feeding into the inlet conduit 141 . For example, feed chamber 133 may function as a flow controller to regulate and provide a constant flow of molten material 121 to reservoir and/or inlet conduit 141 . As shown, mixing chamber 131 may be connected to feed chamber 133 via a third connecting conduit 137 . In some embodiments, molten material 121 may be gravity fed from mixing chamber 131 to feed chamber 133 via third connecting conduit 137 . For example, in some embodiments, gravity may move molten material 121 from mixing chamber 131 through the internal passage of third connecting conduit 137 to feed chamber 133 . Further, as shown, in some embodiments, a feed pipe 139 may be positioned to feed molten material 121 to inlet conduit 141 of molding apparatus 101 , eg, molding vessel 140 .

Forming apparatus 101 is capable of forming various embodiments of formed containers according to features of the present disclosure, e.g., formed containers with wedges for fusion drawing glass ribbons, formed containers with slots for slot drawing glass ribbons, or formed containers. A forming vessel having press rolls for rolling the empty glass ribbon may be provided. In some embodiments, forming apparatus 101 may include sheet redraw by forming apparatus 101, for example, as part of a redraw process. For example, a glass ribbon 104, which may have a predetermined thickness, may be heated and redrawed, resulting in a thinner glass ribbon 104 having a smaller thickness. As an example, the forming vessel 140 shown and disclosed below may be provided for fusion drawing molten material 121 from the lower edge defined as the root 145 of the forming wedge 209 to produce the glass ribbon 103. . For example, in some embodiments, molten material 121 may be fed to forming vessel 140 through inlet conduit 141 . Molten material 121 may then be formed into glass ribbon 103 based in part on the structure of forming vessel 140 . For example, as shown, molten material 121 may be pulled away from the lower edge (eg, root 145) of forming vessel 140 along a withdrawal path extending in direction of travel 154 from glassmaking apparatus 100. FIG. In some embodiments, edge guiders 163 , 164 may guide molten material 121 away from forming vessel 140 to partially define width “W” of glass ribbon 103 . In some embodiments, the width “W” of the glass ribbon 103 extends between a first outer edge 153 of the glass ribbon 103 and a second outer edge 155 of the glass ribbon 103 . In some embodiments, a pull roll assembly 158 may assist in pulling the glass ribbon 103 downward along the direction of travel 154 away from the root 145 . Pull roll assembly 158 may include one or more pull rolls, which may be driven by a motor, for example.

In some embodiments, the width "W" of the glass ribbon 103 extending between the first outer edge 153 of the glass ribbon 103 and the second outer edge 155 of the glass ribbon 103 is about 20 mm (millimeters) or greater, such as about 50 mm or greater, such as about 100 mm or greater, such as about 500 mm or greater, such as about 1000 mm or greater, such as about 2000 mm or greater, such as about 3000 mm or greater, such as about 4000 mm or greater, but in other embodiments may be less than or equal to the widths mentioned above. Or another larger width may be provided. For example, in some embodiments, the width "W" of the glass ribbon 103 is in the range of about 20 mm to about 4000 mm, such as in the range of about 50 mm to about 4000 mm, such as in the range of about 100 mm to about 4000 mm; For example, in the range of about 500 mm to about 4000 mm, such as in the range of about 1000 mm to about 4000 mm, such as in the range of about 2000 mm to about 4000 mm, such as in the range of about 3000 mm to about 4000 mm, such as in the range of about 20 mm to about within the range of 3000 mm, such as in the range of about 50 mm to about 3000 mm, such as in the range of about 100 mm to about 3000 mm, such as in the range of about 500 mm to about 3000 mm, such as in the range of about 1000 mm to about 3000 mm, such as , in the range of about 2000 mm to about 3000 mm, such as in the range of about 2000 mm to about 2500 mm and all ranges and subranges therebetween.

FIG. 2 shows a cross-sectional perspective view of molding apparatus 101 (eg, molding container 140) taken along line 2--2 of FIG. In some embodiments, forming vessel 140 may include a trough 201 positioned to receive molten material 121 from inlet conduit 141 . For illustrative purposes, the mesh shading of molten material 121 has been removed from FIG. 2 for clarity. Forming vessel 140 may further include a forming wedge 209 that extends between opposite ends 210, 211 (see FIG. 1) of forming wedge 209 and a pair of downwardly extending wedges 210,211. It has surface portions 207, 208 which are slanted and tapered. A pair of downwardly slanted tapering surface portions 207 , 208 of forming wedge 209 may taper along direction of travel 154 and meet along root 145 of forming container 140 . The extraction plane 213 of the glass making apparatus 100 may extend along the direction of travel 154 through the root 145 . In some embodiments, the glass ribbon 103 may be drawn in the direction of travel 154 along the drawing plane 213 . As shown, the drawer plane 213 may bisect the forming wedge 209 through the root 145, although in some embodiments the drawer plane 213 extends in another orientation with respect to the root 145. good. In some embodiments, the glass ribbon 103 may travel along a travel path 221 that may be coplanar with the extraction plane 213 in the travel direction 154 .

Additionally, in some embodiments, molten material 121 may flow into and along trough 201 of forming vessel 140 in direction 156 . The molten material 121 may then overflow the trough 201 over the corresponding weirs 203,204 and flow simultaneously downward across the outer surfaces 205,206 of the corresponding weirs 203,204. Each stream of molten material 121 then flows along the downwardly slanted and tapered surface portions 207 , 208 of the forming wedge 209 and the route of the forming vessel 140 where the streams meet and fuse into the glass ribbon 103 . 145. Glass ribbon 103 may then be withdrawn from root 145 along direction of travel 154 at withdrawal plane 213 . In some embodiments, the glass ribbon 103 may have one or more material states based on the vertical position of the glass ribbon 103 . For example, at one location the glass ribbon 103 may have a viscous molten material 121, and at another location the glass ribbon 103 has an amorphous solid (e.g., glass ribbon) in a glassy state. It's okay.

The glass ribbon 103 has a first major surface 215 and a second major surface 216 that face in opposite directions and define a thickness “T” (eg, average thickness) of the glass ribbon 103 . In some embodiments, the thickness "T" of the glass ribbon 103 is no greater than about 2 mm (millimeters), no greater than about 1 mm, no greater than about 0.5 mm, such as no greater than about 300 microns (micrometers), no greater than about 200 microns, or no greater than about 100 microns. less, but in other embodiments other thicknesses may be provided. For example, in some embodiments, the thickness "T" of the glass ribbon 103 is in the range of about 20 μm to about 200 μm, in the range of about 50 μm to about 750 μm, in the range of about 100 μm to about 700 μm, in the range of about 200 μm to about 600 μm, about 300 μm to about 500 μm, about 50 μm to about 500 μm, about 50 μm to about 700 μm, about 50 μm to about 600 μm, about 50 μm to about 500 μm , in the range of about 50 μm to about 400 μm, in the range of about 50 μm to about 300 μm, in the range of about 50 μm to about 200 μm, in the range of about 50 μm to about 100 μm, in the range of about 25 μm to about 125 μm; All thickness ranges and subranges therebetween may be included. Additionally, the glass ribbon 103 may include various compositions such as borosilicate glass, aluminoborosilicate glass, alkali-containing or alkali-free glass, alkali aluminosilicate glass, alkaline earth aluminosilicate glass, soda lime glass, and the like. can be

In some embodiments, a glass separator 149 (see FIG. 1) then separates glass ribbon 104 from glass ribbon 103 along separation path 151 to form a plurality of separated glass ribbons 104 (i.e., a plurality of glass sheet) may be provided. According to another embodiment, longer portions of glass ribbon 104 may be wound onto a storage roll. The separated glass ribbons may then be processed into desired applications, such as display applications. For example, separated glass ribbons can be used to display liquid crystal displays (LCDs), electrophoretic displays (EPDs), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), touch sensors, photovoltaics and other electronic displays. may be used in a wide range of display applications, including

Referring to FIG. 3, an example of the glass making apparatus 100 in area 3 of FIG. 1 is shown. In some embodiments, a method for shaping glass ribbon 103 may include moving glass ribbon 103 along travel path 221 in travel direction 154 at a predetermined ribbon velocity. In some embodiments, the direction of travel 154 may be substantially parallel to the y-axis. In some embodiments, travel path 221 and glass ribbon 103 may be substantially parallel to the x-axis and y-axis, and travel path 221 and glass ribbon 103 may be substantially parallel to the z-axis. may be vertical. In some embodiments, glass making apparatus 100 may include robotic assembly 301 . This robotic assembly 301 may comprise a robotic arm 303 and one or more end effectors 305 . In some embodiments, the one or more end effectors 305 may be attached to the robotic arm 303 . Robot assembly 301 may engage one or more end effectors 305 to glass ribbon 103 . In some embodiments, robotic assembly 301 may move one or more end effectors 305 in travel direction 154 along a path that is substantially parallel to travel path 221 . Robot assembly 301 can apply a bending force to glass ribbon 103 in a direction perpendicular to first major surface 215 and/or second major surface 216 to generate a bending moment about the x-axis. can. For example, a bending moment about the x-axis generated by robot assembly 301 is applied across the score line formed by glass separator 149 (shown, for example, in FIG. 1) across separation path 151 extending along the x-axis. Tensile stress can be generated. This tensile stress causes a crack to propagate through the thickness of the glass ribbon 103, thereby separating a portion of the glass ribbon 103 from an upstream portion of the glass ribbon.

In some embodiments, one or more end effectors 305 may engage first major surface 215 and/or second major surface 216 of glass ribbon 103 . For example, one or more end effectors 305 may comprise multiple end effectors (eg, four end effectors). In some embodiments, one or more end effectors 305 may comprise soft vacuum cups. A vacuum line may be connected to the suction cup and may be attached to a vacuum source capable of generating a negative pressure or vacuum on the suction cup. The suction cups may engage the glass ribbon 103 and, in some embodiments, create a vacuum with the glass ribbon 103 such that relative motion between the glass ribbon 103 and one or more end effectors 305 is limited. A suction attachment may be formed. In some embodiments, the four end effectors engage the first major surface 215 of the glass ribbon 103 in four positions, e.g. Engagement may occur at mating position 311 and fourth engagement position 313 . The first engagement location 307 and the second engagement location 309 may be located adjacent the first outer edge 153 of the glass ribbon 103 . First engagement location 307 and second engagement location 309 may be positioned along direction of travel 154 . The third engagement location 311 and the fourth engagement location 313 may be located adjacent to the second outer edge 155 of the glass ribbon 103 . The third engagement position 311 and the fourth engagement position 313 may be positioned along the travel direction 154 . In some embodiments, glass ribbon 103 may exert a force on one or more end effectors 305 when one or more end effectors 305 engage glass ribbon 103 . For example, forces applied to one or more end effectors 305 may include forces in one or more of the x-axis, y-axis, or z-axis. Additionally or alternatively, the glass ribbon 103 may be oriented around one or more end effectors 305, eg, about an x-axis (eg, M _x ), a y-axis (eg, M _y ), and/or a z-axis (eg, M _z ). Torque may be applied.

Referring to FIG. 4, a side view of glass making apparatus 100 is shown along line 4--4 of FIG. In FIG. 4, the glass ribbon 103 is traveling in the traveling direction 154 along the traveling path 221 . In some embodiments, one or more end effectors 305 of robot assembly 301 may comprise a first end effector 401 and a second end effector 403 . A first end effector 401 may engage the glass ribbon 103 at a first engagement position 307 (eg, shown in FIG. 3), while a second end effector 403 may engage the glass ribbon 103. It may be engaged at a second engagement position 309 (eg, shown in FIG. 3). In some embodiments, the one or more end effectors 305 may comprise a third end effector and a fourth end effector, the third end effector being viewed by the first end effector 401. Hidden, the fourth end effector is hidden from view by the second end effector 403 . The first end effector 401, the second end effector 403, and another end effector may be substantially identical in terms of structure and function, eg, having suction cups.

In some embodiments, robot assembly 301 applies one or more forces (eg, linear force, torque, etc.) on one or more end effectors 305 such that one or more end effectors 305 engage glass ribbon 103 . A sensor 405 can be included that can detect and/or signal information indicative of one or more forces being applied to the glass ribbon 103 by one or more end effectors 305 when applied. In some embodiments, this sensor 405 is a multi-axis or multi-degree-of-freedom force sensor, such as a 6-axis force and/or torque sensor (or 6-DOF force sensor) capable of detecting forces in 6 directions. may contain. In some embodiments, sensor 405 may be configured to detect forces in more or less than six directions. In some embodiments, forces that can be detected by sensor 405 include force F _x in the direction of the x-axis, force F _y in the direction of the y-axis, force F _z in the direction of the z-axis, and force M _x in the direction of the x-axis. It may include a torque (or moment of force) about a torque (or moment of force), a torque (or moment of force) about the _y -axis My, and/or a torque (or moment of force) about the _z -axis Mz. As used herein, the term "force" may include linear force and/or torque force components (eg, along the x-axis, y-axis, z-axis, etc.). In some embodiments, the sensing component of sensor 405 may comprise transducers capable of sensing forces in six directions. Sensor 405 may further comprise programming and/or circuitry capable of generating and transmitting electrical signals conveying information detected. In some embodiments, sensor 405 may have a sampling rate of 50 Hz (Hertz) or higher, or a sampling rate of 100 Hz or higher, for example. Some non-limiting examples of sensor 405 include, for example, the 6 Freedom sensor available from FANUC America Corp. under the tradenames FS-10iA™, FS-30™ and FS-60™. A force sensor, such as a force/torque sensor available from ATI Industrial Automation, Inc. under the trade name Omega160™, may be included.

In some embodiments, the glass making apparatus 100 may include a control assembly 409 that can receive data from the sensors 405 and operate the robotic arm 303 . The control assembly 409 includes a control device (eg, computer, computer-like device, programmable logic controller, etc.) configured (eg, programmed, coded, designed and/or manufactured) to operate the robotic arm 303. Be prepared. For example, control assembly 409 may be electrically (eg, wired or wireless) connected to sensor 405 and robotic arm 303 . In some embodiments, control assembly 409 may receive force data 411 from sensor 405 . Control assembly 409 may send motion instructions 413 to robotic arm 303 . In some embodiments, control assembly 409 may comprise one or more controllers, eg, first controller 415 and second controller 417 . In some embodiments, a first controller 415 may control the motion of the robotic arm 303, while a second controller 417 controls force data 411 from sensors 405 (e.g., force-related feedback information). ) may be processed and/or analyzed to produce response adjustments to the robotic arm 303 . For example, motion instructions 413 may be sent from the first controller 415 to the robotic arm 303 and/or to a separate controller provided on the robotic arm 303 that controls the movement of segments of the robotic arm 303 . good. The robotic arm 303 can move in response to motion commands 413 . For example, motion instructions 413 may specify one or more of a path that robotic arm 303 may travel, a speed of robotic arm 303, a distance traveled by robotic arm 303, and the like. Accordingly, the robot arm 303 can move according to the motion instructions 413 .

First controller 415 may receive force data 411 from sensor 405 and then first controller 415 may send force data 411 to second controller 417 . In some embodiments, force data 411 from sensor 405 may be sent directly to second controller 417 by bypassing first controller 415 . Glass ribbon 103 may apply a force to one or more end effectors 305 , which force is configured to be detected by sensor 405 and communicated as part of force data 411 to control assembly 409 . For example, force data 411 is detected along one or more of the x-axis, y-axis, z-axis, torque about the x-axis, torque about the y-axis, or torque about the z-axis. It may contain the power that can A second controller 417 may determine possible adjustments to the motion of the robotic arm 303 , eg, changes or adjustments in one or more of the position, path or velocity of one or more end effectors 305 . Adjustments determined by second controller 417 may be based in part on force data 411 received by second controller 417 . In some embodiments, second controller 417 may send these adjustments as adjustment data 419 to first controller 415 . This first controller 415 may receive adjustment data 419 from a second controller 417 and incorporate this adjustment data 419 into motion instructions 413 for the robot arm 303 . In some embodiments, a user may enter user input data 421 into first controller 415 . For example, in some embodiments, user input data 421 may represent motion instructions 413 for robotic arm 303 during a first motion cycle of robotic arm 303 . In this case, user input data 421 may include one or more of initial positions, initial paths, or initial velocities of one or more end effectors 305 . In some embodiments, motion instructions 413 may then be modified based on force data 411 such that user input data 421 is no longer implemented.

In some embodiments, a method for shaping the glass ribbon 103 includes engaging the glass ribbon 103 with end effectors (eg, one or more end effectors 305) attached to a robotic arm 303. you can stay For example, robotic arm 303 may move one or more end effectors 305 between disengaged position 427 and engaged position 429 . In the disengaged position 427, the one or more end effectors 305 are not in contact with or engaged with the glass ribbon 103 and are spaced a predetermined distance from a major surface (eg, first major surface 215) of the glass ribbon 103. you can To engage glass ribbon 103 , robotic arm 303 may move one or more end effectors 305 toward glass ribbon 103 in engagement direction 425 . The one or more end effectors 305 are moved in the engagement direction 425 and, at least thereafter, the one or more end effectors 305 engage the first major surface 215 thereby causing the first major surface 215 and the first major surface 215 to move. suction attachment can be formed. Once the one or more end effectors 305 are engaged with the glass ribbon 103, the glass ribbon 103 and the one or more end effectors 305 can move together such that the glass ribbon 103 and the one or more end effectors 305 can move together. 305 can be substantially restricted.

FIG. 5 shows one or more end effectors 305 engaged with the first major surface 215 of the glass ribbon 103 (eg, at engagement locations 429). For example, the one or more end effectors 305 may engage the first ribbon portion 501 of the glass ribbon 103 . This first ribbon portion 501 may be located downstream of the second ribbon portion 503 of the glass ribbon 103 with respect to the direction of travel 154 . For example, as the glass ribbon 103 moves along the direction of travel 154, the first ribbon portion 501 can pass a given position, and then the second ribbon portion 503 can pass the same position. In some embodiments, the first cycle of motion is from engagement of one or more end effectors 305 (eg, shown in FIG. 4) to first ribbon portion 501 to movement from second ribbon portion 503. Separation of the first ribbon portion 501 (eg, shown in FIG. 7) may follow.

In some embodiments, a method for shaping glass ribbon 103 includes moving one or more end effectors 305 at a predetermined robot speed, such as first robot speed 505, in direction of travel 154. good. For example, the glass ribbon 103 may move along the travel path 221 in the travel direction 154 at the predetermined ribbon speed 507 . In some embodiments, the method for shaping the glass ribbon 103 includes a force exerted on one or more end effectors 305 by the first ribbon portion 501 of the glass ribbon 103 during a first cycle of operation, e.g. It may include detecting a force of 1. For example, in some embodiments, the ribbon velocity and ribbon path of the first ribbon portion 501 may match preprogrammed robot velocities and robot paths of one or more end effectors 305, or may be combined. It doesn't have to be.

In some embodiments, first robot velocity 505 and ribbon velocity 507 are substantially offset from each other, e.g., by having the same magnitude and the same direction as each other (e.g., along travel direction 154). can be the same. The first robot velocity 505 and the ribbon velocity 507 are substantially the same as each other, and the paths traveled by the first ribbon portion 501 and the one or more end effectors 305 are substantially parallel to each other In that case, the first ribbon portion 501 and the one or more end effectors 305 may be traveling at the same speed as each other along paths parallel to each other. Thus, the first force that can be detected can be zero or close to zero. For example, since first robot velocity 505 and ribbon velocity 507 are substantially the same as each other, the relative motion between first ribbon portion 501 and one or more end effectors 305 along the y-axis is negligible, which can lead to a first force of zero or near-zero value. In some embodiments, the first force is along multiple axes (e.g., x-axis, y-axis, z-axis, torque about the x-axis, torque about the y-axis and/or or along the torque about the z-axis) may be detected at multiple locations.

As used herein, the term "speed" (e.g., used by first robot speed 505, ribbon speed 507, other speeds herein, etc.) refers to a single speed (e.g., a single is not limited to a single magnitude of velocity in the direction of Rather, in some embodiments, "velocity" as used herein may have a varying series of velocities. For example, during an operating cycle, in some embodiments, the velocities, e.g., one or more of first robot velocity 505, ribbon velocity 507, etc., are maintained at a constant velocity (e.g., constant velocity in a single direction). speed). However, in some embodiments, "speed" is not limited to a constant speed, but rather a range of speeds that vary during the operating cycle. For example, in some embodiments, the velocities (eg, first robot speed 505, ribbon speed 507, etc.) may change during the motion cycle, eg, about every 10 ms to about every 50 ms. A changing speed may include, for example, a changing magnitude and/or a changing direction of speed. Thus, "velocity" during an operating cycle may have multiple velocities that may vary in speed and/or direction.

In some embodiments, the method for shaping the glass ribbon 103 reduces the speed of the one or more end effectors 305 from the first robot speed 505 when the force magnitude exceeds a predetermined value. A change to a second robot speed 509 may be included. The force magnitude may include the absolute value of the force. For example, sensor 405 can detect the force exerted by first ribbon portion 501 on one or more end effectors 305 . Sensor 405 may transmit this force to first controller 415 as force data 411 , which may then be transmitted to second controller 417 . In some embodiments, second controller 417 may compare the magnitude of force data 411 to a predetermined value that may be set by a user. In some embodiments, force data 411 determines, for example, that first robot velocity 505 and ribbon velocity 507 are substantially the same as each other, and that first ribbon portion 501 and one or more end effectors 305 may include force magnitudes that may be within a predetermined range of values when the relative motion between is zero. Accordingly, force data 411 may indicate forces that may be within a predetermined range of values, which are zero or near-zero values. In some embodiments, if the magnitude of the force detected by sensor 405 is within a predetermined range of values, the speed of one or more end effectors 305 may not change; The speed of one or more end effectors 305 may be maintained constant. Thus, the first controller 415 does not change the motion commands 413 sent to the robot arm 303 .

In some embodiments, for example, if first robot velocity 505 and ribbon velocity 507 are not the same as each other and there is relative motion between first ribbon portion 501 and one or more end effectors 305 , the magnitude of the force data 411 exceeds a predetermined value. Accordingly, the force data 411 may indicate a force that is not near zero, but is greater than zero or less than zero, thus exceeding a predetermined value. In some embodiments, the speed of one or more end effectors 305 may be changed when the magnitude of the force detected by sensor 405 exceeds a predetermined value. For example, the first controller 415 changes the motion command 413 sent to the robot arm 303 to change the speed of the robot arm 303 from a first robot speed 505 to a second robot speed 509 . may be provided. As can be seen, in FIG. 5 the lines representing the first robot speed 505 and the second robot speed 509 have different lengths, which causes the first robot speed 505 to the second robot speed A change in velocity of one or more end effectors 305 to 509 can be represented. In some embodiments, the second robot speed 509 may be closer to the ribbon speed 507 than the first robot speed 505, e.g. The difference is less than a second difference between first robot speed 505 and ribbon speed 507 . In some embodiments, if the second robot velocity 509 is substantially the same as the ribbon velocity 507, thereby allowing the force detected by the sensor 405 to be zero or near zero, the sensor The force detected by 405 cannot exceed a predetermined value. However, in some embodiments, if the second robot velocity 509 is different than the ribbon velocity 507 such that the force detected by sensor 405 may be zero or near zero, sensor 405 cannot exceed a predetermined value. Thus, varying the speed can occur if the magnitude of the first force exceeds a predetermined value, but if the magnitude of the first force is within a range of predetermined values, , must not change speed.

In some embodiments, first ribbon portion 501 may apply force to one or more end effectors 305 along first force direction 511 , which may be in the same direction as direction of travel 154 . When first ribbon portion 501 applies a force along first force direction 511, ribbon velocity 507 may be greater than first robot velocity 505, thereby causing first ribbon portion 501 to move one It may progress faster than the end effector 305 described above. To compensate for this difference between ribbon speed 507 and first robot speed 505, second robot speed 509 may be greater (e.g., faster) than second robot speed 509; allows the second robot speed 509 to be more accurately matched to the ribbon speed 507 . In some embodiments, first ribbon portion 501 exerts a force on one or more end effectors 305 along a second force direction 513 that may be opposite first force direction 511 and travel direction 154 . You can add When first ribbon portion 501 applies a force along second force direction 513, ribbon velocity 507 may be less than first robot speed 505, thereby causing first ribbon portion 501 to move one It may move at a lower speed than the end effector 305 described above. To compensate for this difference between ribbon speed 507 and first robot speed 505, second robot speed 509 may be less (e.g., slower) than second robot speed 509, which allows the second robot speed 509 to be more accurately matched to the ribbon speed 507 .

In some embodiments, the method for shaping the glass ribbon 103 changes the ribbon velocity 507 to the robot velocity (e.g., the first robot velocity 505 or Quantifying the ribbon velocity 507 by correlating it to a second robot velocity 509) may be included. For example, in some embodiments, the robot speed of one or more end effectors 305 (eg, first robot speed 505 or second robot speed 509) is substantially equal to ribbon speed 507 of first ribbon portion 501. In the case of a symmetrical match, there is negligible relative motion between the first ribbon portion 501 and the one or more end effectors 305, thereby reducing the first force to zero or zero. values can be close. In some embodiments, the magnitude of the first force may be within a predetermined range of values when the first force is at or near zero. Thus, a first force magnitude within a predetermined range of values indicates that the robot velocity (eg, first robot velocity 505 or second robot velocity 509) is substantially matched to ribbon velocity 507. can be viewed. Since the first controller 415 sends motion commands 413 to the robot arm 303, the robot velocity, eg, the magnitude of the robot velocity, may be a known quantity. Thus, ribbon velocity 507 is quantified by correlating ribbon velocity 507 to a robot velocity (e.g., first robot velocity 505 or second robot velocity 509), e.g., assigning a known robot velocity to ribbon velocity 507. can do.

In some embodiments, when the magnitude of the first force exceeds a predetermined value, there is relative motion between the first ribbon portion 501 and the one or more end effectors 305, thereby causing the first Sometimes the power of 1 cannot be ignored. In some embodiments, relative motion may cause the magnitude of the first force to exceed a predetermined value. If the first force magnitude is above a predetermined value, the robot velocity can be considered different from ribbon velocity 507 . Thus, the robot speed is changed to substantially match the ribbon speed 507, thereby quantifying the ribbon speed 507 until the magnitude of the first force is within a predetermined range of values. You may not be able to change it.

In some embodiments, quantifying ribbon velocity 507 may include determining one or more of an average ribbon velocity or an instantaneous ribbon velocity. For example, in some embodiments, quantifying ribbon velocity 507 is a measure of glass ribbon 501 velocity from engagement of one or more end effectors 305 (eg, shown in FIG. 4) to first ribbon portion 501 . to separation of the first ribbon portion 501 from the second ribbon portion 503 (eg, shown in FIG. 7). For example, this average ribbon velocity is given by equation (1):

can be represented by

In equation (1), P(t _start ) can represent the position of first ribbon portion 501 when one or more end effectors 305 first engage first ribbon portion 501 . P(t _end ) can represent the position of first ribbon portion 501 when first ribbon portion 501 is separated from second ribbon portion 503 (eg, shown in FIG. 7). This allows the numerator of equation (1) (eg, P(t _end )−P(t _start )) to be the first can represent the distance traveled by the first ribbon portion 501 up to the point at which the ribbon portion 501 of is separated from the second ribbon portion 503 . In some embodiments, t _start can represent the point in time when one or more end effectors 305 first engage the first ribbon portion 501, while t _end represents the first ribbon portion 501. It can represent the point in time when portion 501 is separated from second ribbon portion 503 . Thus, the denominator (eg, t _end −t _start ) of equation (1) is calculated from when the one or more end effectors 305 first engage the first ribbon portion 501 to when the first ribbon portion 501 is the first ribbon portion 501 . It can represent the elapsed time between two ribbon portions 503 being separated. Thus, the average ribbon velocity of the first ribbon portion 501 is, for example, from when the one or more end effectors 305 first engage the first ribbon portion 501 to when the first ribbon portion 501 is equal to the second ribbon portion 501 . It can be determined during the first cycle of operation until it is separated from portion 503 .

Additionally or alternatively, in some embodiments, quantifying the ribbon velocity includes measuring the instantaneous ribbon velocity during a sampling period, which may be less than about 2 milliseconds (ms), less than about 1 millisecond, etc. It may include determining. For example, this instantaneous ribbon velocity may include the real-time ribbon velocity of the glass ribbon 103 within the sampling period. In some embodiments, the instantaneous ribbon velocity is given by equation (2):

can be represented by

In equation (2), Δt may represent the sampling period, which may be less than approximately 2 milliseconds. P(t _k ) can represent the position of the first ribbon portion 501 at time t _k , whereas P(t _k +Δt) is at time t _k +Δt, in other words the sampling period can represent the position of the first ribbon portion 501 after . For example, the numerator of equation (2) (eg, P(t _k +Δt)−P(t _k )) indicates that the first ribbon portion 501 is sampled in less than about 2 ms, less than about 1 ms, etc. It can represent the distance traveled during the period Δt. In some embodiments, the sampling period may be in the range of approximately 1 millisecond to approximately 2 milliseconds. The denominator Δt in equation (2) can represent, for example, the elapsed time of the sampling period. Thus, the instantaneous ribbon velocity of first ribbon portion 501 can be determined during the sampling period.

In some embodiments, a method for shaping glass ribbon 103 may include adjusting parameters of glass ribbon 103 based on ribbon speed 507 . For example, in some embodiments, once ribbon speed 507 is known (eg, average ribbon speed and/or instantaneous ribbon speed), parameters of glass ribbon 103 may be adjusted to compensate for ribbon speed 507. . For example, if the ribbon speed 507 is less than the target ribbon speed, adjusting the parameters may include maintaining constant lengths of the first ribbon portion 501 and the second ribbon portion 503 of the glass ribbon 103. may contain Since the ribbon speed 507 is less than the target ribbon speed, the separation of the first ribbon portion 501 from the second ribbon portion 503 is delayed to compensate for the slower ribbon speed 507, thereby causing the first The length of ribbon portion 501 can be made longer before separation. If the ribbon speed 507 is faster than the target ribbon speed, separation of the first ribbon portion 501 from the second ribbon portion 503 occurs earlier, thereby increasing the length of the first ribbon portion 501. It can be made shorter before separation. In some embodiments, additional parameters that may be adjusted may include, for example, localized heating of the glass ribbon 103, changes in the chemistry of the glass ribbon 103, and the like. In some embodiments, the second ribbon portion 503 is separated from the upstream portion of the glass ribbon 103 such that the length of the second ribbon portion 503 matches the length of the first ribbon portion 501 . may be separated. Therefore, in some embodiments, a constant length of first ribbon portion 501 and second ribbon portion 503 can be maintained. In some embodiments, the length of first ribbon portion 501 and/or second ribbon portion 503 may be adjusted across the width of first ribbon portion 501 and/or second ribbon portion 503 . For example, in some embodiments, the length of first ribbon portion 501 and/or second ribbon portion 503 (eg, and another ribbon portion of glass ribbon 103) is , along the second outer edge 155 and/or at locations between the first outer edge 153 and the second outer edge 155 . In some embodiments, changing and/or maintaining the length of a ribbon portion (eg, first ribbon portion 501, second ribbon portion 503, etc.) is a process parameter change, such as tensioning. This may be done based on changes in the diameter of the roll assembly 158, the speed of the glass separator 149, and the like.

Referring to FIG. 6, in some embodiments, a score line 601 may be formed in the glass ribbon 103 as part of the separation process. For example, a glass separator 149 may form a score line 601 in the second major surface 216 to separate the first ribbon portion 501 from the second ribbon portion 503, but additionally or alternatively , this score line 601 may be formed on the first major surface 215 . In some embodiments, score line 601 may define a boundary between first ribbon portion 501 and second ribbon portion 503 . For example, the first ribbon portion 501 may be positioned on one side of the score line 601 while the second ribbon portion 503 is positioned on the opposite side of the score line 601. good.

6-7, in some embodiments, the method for shaping the glass ribbon 103 includes moving the first ribbon portion 501 of the glass ribbon 103 to the length of the glass ribbon 103 before changing the speed. Separating from the second ribbon portion 503 may be included. For example, as shown in FIG. 7, a first cycle of motion manipulates robotic arm 303 to move one or more end effectors 305 to move first ribbon portion 501 to the remainder of glass ribbon 103, For example, it may involve bending relative to the second ribbon portion 503 . In some embodiments, one or more end effectors 305 pivot the first ribbon portion 501 at the score line 601 about the x-axis, e.g., counterclockwise about the x-axis. good. First ribbon portion 501 can be separated from second ribbon portion 503 by pivoting first ribbon portion 501 relative to second ribbon portion 503 at score line 601 . . In some embodiments, first ribbon portion 501 may be moved in separation direction 701 away from second ribbon portion 503 and away from travel path 221 along which second ribbon portion 503 travels. In some embodiments, the robotic arm 303 moves the first ribbon portion 501 to another area to release the first ribbon portion 501 from the one or more end effectors 305, thereby allowing one The end effector 305 can be disengaged from the first ribbon portion 501 .

In some embodiments, the robotic arm 303 begins with one or more end effectors 305 engaging the first ribbon portion 501 during a first motion cycle, e.g. may move at a first robot speed 505 for a period of time ending with the separation of the first ribbon portion 501 of . A method for shaping the glass ribbon 103 by moving at a first robot speed 505 over a period of a first operating cycle includes, for example, engaging one or more end effectors 305 to the first ribbon portion 501 . maintain the speed of the one or more end effectors 305 at the first robot speed 505 throughout the first cycle of motion during the period from mating to separation of the first ribbon portion 501 from the second ribbon portion 503; may include doing By maintaining the speed of the one or more end effectors 305 and separating the first ribbon portion 501 before changing the speed, during the first cycle of operation, a second One or more end effectors 305 can be held at the first robot speed 505 without changing to a robot speed 509 of two.

In some embodiments, the speed of the one or more end effectors 305 is maintained at the first robot speed 505 because the magnitude of the force detected by the sensor 405 is within a predetermined range of values. good. For example, if the first robot velocity 505 is substantially the same as the ribbon velocity 507, the force detected by the sensor 405 may be zero or near zero, and thus the magnitude of the force is , may be within a predetermined range of values. However, in some embodiments, the speed of the one or more end effectors 305 is maintained at the first robot speed 505 during the first motion cycle regardless of the force detected by the sensor 405. may be For example, it may be beneficial to maintain the one or more end effectors 305 at the first robot speed 505 during the first motion cycle even if the magnitude of the force detected by the sensor 405 exceeds a predetermined value. obtain. This may be due in part to the reduced demand for data acquisition and computational power. For example, by not changing the first robot speed 505 to the second robot speed 509 during the first motion cycle, the first controller 415 to the robot arm 303 (eg, in the form of updated motion instructions 413) ) can reduce data transmission. Further, due to the reduced demand for generating motion instructions 413, computational power may be reduced as well. Thus, in some embodiments, the control assembly 409 adjusts the robot velocity in real-time ( It may change from a first robot speed 505 to a second robot speed 509 (eg, as described with respect to FIG. 5). However, in another embodiment, control assembly 409 controls the robot speed to first robot speed 505 during the first motion cycle even if the magnitude of the force detected by sensor 405 exceeds a predetermined value. may be maintained. In some embodiments, control assembly 409 receives force data 411 throughout the first motion cycle, regardless of whether control assembly 409 changes the robot velocity during the first motion cycle, and this Force data 411 may be stored in memory, for example. Force data 411 that may be stored includes, for example, forces detected by sensors 405, velocities of one or more end effectors 305 (eg, first robot velocity 505, second robot velocity 509, etc.), robot velocities, It may include one or more of ribbon velocity 507 estimated based on forces detected by sensor 405, instantaneous ribbon velocity, average ribbon velocity, and the like.

8, in some embodiments, a method for forming glass ribbon 103 separates first ribbon portion 501 prior to engaging second ribbon portion 503 (e.g., in FIG. 7). shown). For example, one or more end effectors 305 may be disengaged from the first ribbon portion 501 when the first ribbon portion 501 is separated from the second ribbon portion 503 . In some embodiments, the method for shaping the glass ribbon 103 includes engaging the second ribbon portion 503 of the glass ribbon 103 before changing the speed of the one or more end effectors 305 . may contain. For example, in some embodiments, control assembly 409 reduces the robot speed to first robot speed 505 during the first motion cycle even if the magnitude of the force detected by sensor 405 exceeds a predetermined value. can be maintained at The one or more end effectors 305 may engage the second ribbon portion 503 after completing a first cycle of operation in which the first ribbon portion 501 may be separated from the second ribbon portion 503 . For example, one or more end effectors 305 engage first ribbon portion 501 (eg, robot arm 303 moves one or more end effectors 305 in engagement direction 425, as shown in FIG. 4). The second ribbon portion 503 may be engaged in substantially the same manner as the mating one or more end effectors 305 . In some embodiments, a method for shaping glass ribbon 103 may include engaging one or more end effectors 305 with second ribbon portion 503 after the first cycle of operation. Engagement of the one or more end effectors 305 with the second ribbon portion 503 represents the initiation of a second operating cycle that may continue until the second ribbon portion 503 is separated from the third ribbon portion 801. be able to.

In some embodiments, the speed of one or more end effectors 305 may be changed (eg, from first robot speed 505) to second robot speed 509 before beginning the second motion cycle. . For example, during a first operating cycle, first controller 415 may receive force data 411 from sensor 405 . This force data 411 represents a first force applied to one or more end effectors 305 by a first ribbon portion 501 (eg, shown in FIGS. 4-7). If this first force magnitude is within a predetermined range of values over the duration of the first motion cycle, then the first robot velocity 505 (eg, shown in FIGS. 5-7) is the ribbon It may be substantially the same as velocity 507 . However, if the first force magnitude exceeds a predetermined value during the first motion cycle, first robot velocity 505 (eg, shown in FIGS. 5-7) is reduced to ribbon velocity 507 is different from In some embodiments, the first force may indicate this difference in velocity, which causes the second controller 417 to process and/or analyze the first force to produce the first Corrections to robot velocity 505 can be determined. For example, the second controller 417 generates a second robot velocity 509 that may include a correction to the first robot velocity 505 based on the first force and converts the second robot velocity 509 to adjustment data. 419 to the first controller 415 . In response, this first controller 415 may send a motion command 413 to the robot arm 303 that may include a second robot speed 509 . In some embodiments, the robotic arm 303 may then move one or more end effectors 305 at the second robot speed 509 for the duration of the second motion cycle. Thus, in some embodiments, the method for shaping the glass ribbon 103 modifies the velocity of one or more end effectors 305 (eg, shown in FIGS. 5-7) to a third force based on a first force. changing from one robot speed 505 to a second robot speed 509; and moving one or more end effectors 305 at the second robot speed 509 in the direction of travel 154 during a second motion cycle. can be In some embodiments, the difference between second robot speed 509 and ribbon speed 507 may be less than the difference between first robot speed 505 and ribbon speed 507 .

In some embodiments, a method for shaping glass ribbon 103 detects a second force applied to one or more end effectors 305 by second ribbon portion 503 during a second cycle of operation. may include For example, detecting the second force may be substantially the same as detecting the first force (eg, as shown and described with respect to FIG. 5). In some embodiments, second robot velocity 509 and ribbon velocity 507 are substantially the same, e.g., by having the same magnitude and the same direction as each other (e.g., along travel direction 154). can be When second robot speed 509 and ribbon speed 507 are substantially the same as each other, second ribbon portion 503 and one or more end effectors 305 travel at the same speed along the same path as each other. It's okay. Thus, the second force that may be detected may be zero or near zero. In some embodiments, the second robot velocity 509 of the one or more end effectors 305 is reduced from the first robot velocity 505 to the second velocity if the magnitude of the second force exceeds a predetermined value. to robot speed 509 (eg, to a third speed).

Referring to FIG. 9, in some embodiments, a method for shaping glass ribbon 103 includes separating second ribbon portion 503 from third ribbon portion 801 prior to engagement with third ribbon portion 801 . may include separating from For example, second ribbon portion 503 may be removed in substantially the same manner as first ribbon portion 501 is removed from second ribbon portion 503 (eg, shown in FIG. 7). For example, glass separator 149 may form score line 901 in glass ribbon 103 , eg, second major surface 216 and/or first major surface 215 . In some embodiments, this score line 901 may define the boundary between the second ribbon portion 503 and the third ribbon portion 801 . For example, the second ribbon portion 503 may be located on one side of the score line 901 while the third ribbon portion 801 is located on the opposite side of the score line 901. good. In some embodiments, during the second cycle of motion, robotic arm 303 is manipulated to move one or more end effectors 305 to move second ribbon portion 503 to the remainder of glass ribbon 103, e.g. may be bent relative to the ribbon portion 801 of the . In some embodiments, one or more end effectors 305 may pivot the second ribbon portion 503 at the score line 901 about the x-axis, such as counterclockwise about the x-axis. . Second ribbon portion 503 can be separated from third ribbon portion 801 by pivoting second ribbon portion 503 relative to third ribbon portion 801 at score line 901 . .

In some embodiments, the method for shaping the glass ribbon 103 includes forming the second ribbon from the third ribbon portion 801 from the engagement of the one or more end effectors 305 to the second ribbon portion 503 . This may include maintaining the velocity of the one or more end effectors 305 at the second robot velocity 509 throughout the second operating cycle until separation of the portion 503 . For example, maintaining the speed of the one or more end effectors 305 at the second robot speed 509 throughout the second motion cycle increases the speed of the one or more end effectors 305 during the first motion cycle ( It may be substantially the same as maintaining a first robot speed 505 (eg, shown in FIGS. 5-7). In some embodiments, the velocity of the one or more end effectors 305 may reach the second robot velocity 509 because the magnitude of the second force detected by the sensor 405 is within a predetermined range of values. may be maintained. The magnitude of second robot velocity 509 may be substantially the same as ribbon velocity 507 if the second force is within a predetermined range of values. However, in some embodiments, the speed of the one or more end effectors 305 is maintained at the second robot speed 509 during the second motion cycle, regardless of the force detected by the sensor 405. may be For example, to reduce the demands on data acquisition and computing power, control assembly 409 may control the robot velocity to the second motion even if the magnitude of the second force detected by sensor 405 exceeds a predetermined value. Do not change from second robot speed 509 to third robot speed in real time during the cycle. In some embodiments, the control assembly 409 receives force data 411 through the second motion cycle and converts this force data 411 into, for example, a May be stored in memory.

Referring to FIG. 10, in some embodiments, a method for shaping glass ribbon 103 includes engaging one or more end effectors 305 to a third ribbon portion of glass ribbon 103 after the second cycle of operation. may include mating. For example, in some embodiments, after completing a second cycle of operation in which second ribbon portion 503 may be separated from third ribbon portion 801, one or more end effectors 305 move the second ribbon portion It may be disengaged from 503 and engaged with the third ribbon portion 801 . The one or more end effectors 305 engage the third ribbon portion 801 in substantially the same manner as the one or more end effectors 305 engage the first ribbon portion 501 and/or the second ribbon portion 503 . may be combined. This engagement of one or more end effectors 305 with the third ribbon portion 801 continues until the third ribbon portion 801 is separated from another portion of the glass ribbon 103 (eg, the fourth ribbon portion). It can represent the beginning of a good third operating cycle.

In some embodiments, the method for shaping the glass ribbon 103 includes first or a second force (eg, applied to one or more end effectors 305 during the second cycle of operation shown in FIGS. 7-9), one or more changing the speed of the end effector 305 from a second robot speed 509 (eg, shown in FIGS. 5-9) to a third speed 1001; at the third robot speed 1001 in the direction of travel 154 . For example, in some embodiments, the speed of the one or more end effectors 305 from the second robot speed 509 to the third robot speed 1001 is the speed from the most recent motion cycle, eg, the second motion cycle. It may be varied based on force data 411 . In some embodiments, second robot velocity 509 differs from ribbon velocity 507 when the magnitude of the second force detected during the second motion cycle exceeds a predetermined value. A second force may indicate this difference in velocity, by which the second controller 417 processes and/or analyzes the second force to determine a correction to the second robot velocity 509. can do. For example, second controller 417 may generate third robot velocity 1001 that may include a correction to second robot velocity 509 . This third robot speed 1001 may be sent as adjustment data 419 to the first controller 415 , and in response this first controller 415 may send a motion command 413 to the robot arm 303 . . Robot arm 303 may then move one or more end effectors 305 at third robot speed 1001 for the duration of a third motion cycle.

In some embodiments, changing the speed of one or more end effectors 305 from second robot speed 509 to third robot speed 1001 is based on force data 411 from the most recent motion cycle. It is not limited. Rather, in some embodiments, the velocity is varied based on a combination of a first force detected during a first cycle of motion and a second force detected during a second cycle of motion. be taken. For example, in some embodiments, the second controller 417 determines the correction to the second robot velocity 509 by, for example, averaging the first force and the second force. The force and the second force may be combined. Second controller 417 may then generate third robot velocity 1001 , which may be transmitted to robot arm 303 via motion command 413 by first controller 415 .

FIG. 11 shows an exemplary control diagram 1101 or control architecture representing controls that may be performed by control assembly 409 . In some embodiments, a user may first enter user input data 421 into control algorithm 1103 . This control algorithm 1103 may compare force data from sensor 405 with user input data 421 . Based on the difference between the force magnitude detected by sensor 405 and user input data 421, control algorithm 1103 may generate motion instructions 1104 to robot controller 1105, which may control motion of robot arm 303. . Sensors 405 may detect forces exerted by glass ribbon 103 on one or more end effectors 305 and transmit force data 411 to filter 1107, after which signal filtering of force data 411 may be performed. In some embodiments, force data 411 may then be transmitted to memory 1109 for storage. For example, this memory 1109 may store force data for some or all of the operating cycles, eg, a first operating cycle, a second operating cycle, and so on. In some embodiments, the stored force data from the motion cycle may be sent to the control algorithm 1103, which then compares the force data to a predetermined value, thus issuing the motion command 1104. may be updated.

In some embodiments, the control algorithm 1103 uses equation (3):

can be represented by

(3), t can represent the sampled time series within one operating cycle, and Δy _k−1 (t) is the desired force distribution (eg, during the operating cycle) and the sensor 405 can represent the difference between the actual force distribution y _k−1 detected by Φ can represent an update rule that can be causal or non-causal. For example, the update rule may be Φ=-α, which can measure the effectiveness of the algorithm. By using this iterative learning control algorithm, the initial user input data 421 may or may not be accurate. Rather, in some embodiments, control algorithm 1103 detects inaccuracies in user input data 421 by detecting forces on one or more end effectors 305 and adjusting one or more end effectors 305 . can be compensated. Therefore, over time, the control algorithm 1103 will reduce the error between the desired force distribution and the actual force distribution.

FIG. 12 shows the relationship between time and force detected by sensor 405 over a given operating cycle. The x-axis (e.g., horizontal axis) represents time (e.g., in seconds), while the y-axis (e.g., vertical axis) represents force (e.g., in Newtons "N") detected by sensor 405. ing. A first line 1201 represents time and detected force over a first operating cycle. A second line 1203 represents time and detected force over a second cycle of motion following the first cycle of motion. A third line 1205 represents time and detected force over a third cycle of motion following the second cycle of motion. A fourth line 1207 represents time and detected force over a fourth operating cycle following the third operating cycle. In some embodiments, the first operating cycle is performed without any adjustments or corrections made during the cycle. After the first cycle of motion, adjustments are made to the speed and path of one or more end effectors 305 based on the forces detected during the first cycle of motion. A second cycle of operation represented by a second line 1203 follows a path based on adjustments from the first cycle of operation. After the second cycle of motion, another adjustment to the speed and path of one or more end effectors 305 is made based on the forces detected during the second cycle of motion. A third cycle of operation represented by a third line 1205 follows a path based on adjustments from the second cycle of operation. After the third cycle of motion, another adjustment to the speed and path of one or more end effectors 305 is made based on the forces detected during the third cycle of motion. A fourth operating cycle represented by a fourth line 1207 follows a path based on adjustments from the third operating cycle.

In some embodiments, the first operating cycle represented by the first line 1201 experiences the greatest force differential, which over time increases from about -15 N at 0 seconds to 401 seconds at 401 seconds. of about -60N. A second operating cycle, represented by a second line 1203, experiences a second maximum force difference, which increases over time from about -15 N at 0 seconds to about -35 N at 401 seconds. up to The third operating cycle, represented by the third line 1205, experiences the third largest force difference, which increases over time from about -15 N at 0 seconds to about -20 N at 401 seconds. up to The fourth operating cycle, represented by the fourth line 1207, experiences a minimal force difference that increases over time from about -15 N at 0 seconds to about -5 N at 401 seconds. . Accordingly, after each motion cycle, corrections to the speed and path of one or more end effectors 305 can be made based on the forces detected during the most recently completed motion cycle. Each subsequent cycle of motion can achieve a smaller force differential, thereby allowing control algorithm 1103 of FIG. It can be shown that the speed and/or path of the ribbon 103 can be matched more precisely.

Glass making apparatus 100 can provide a number of advantages. For example, by adjusting the speed and/or path of one or more end effectors 305 after a given cycle of motion rather than in real time, data acquisition and computational power requirements may be reduced. , the improvement in force reduction between the one or more end effectors 305 and the glass ribbon 103 can be further improved. Additionally, ribbon velocity 507 is correlated to robot velocity (eg, first robot velocity 505, second robot velocity 509, etc.) when the magnitude of the force detected by sensor 405 is within a predetermined range of values. The ribbon velocity 507 can be quantified by letting Once the magnitude of the ribbon velocity 507 is known, the parameters of the glass ribbon 103, such as the length of the glass ribbon 103, can be adjusted to compensate for this ribbon velocity 507, thereby increasing the ribbon The portions can each have the same length. In some embodiments, the ribbon speed 507 may change over time due to, for example, wear of the pull roll assembly 158 and gradual reduction in the diameter of the pull roll assembly 158 . These changes in ribbon velocity 507 can be compensated for by control assembly 409 to provide a matched velocity and/or travel path between one or more end effectors 305 and glass ribbon 103. can. Further, in some embodiments, the time for the force detected by sensor 405 to decrease from a value above a predetermined value to a value within a predetermined range of values can be accelerated, for example, within a few seconds. can. For example, in less than a few seconds, sensor 405 can detect that the force magnitude exceeds a predetermined value, thereby causing one or more end effectors 305 to make adjustments to speed or path. can be generated, which can provide a force return to approximately zero (eg, within a predetermined range of values).

The embodiments and functional operations described herein may be implemented in a digital electronic circuit, or computer software, firmware or hardware, or one of these, including the structures disclosed herein and structural equivalents thereof. One or more combinations may be implemented. The embodiments described herein may be implemented in one or more computer program products, i.e., computer programs encoded on a tangible program carrier for execution by or for controlling operation of a data processing apparatus. It may be implemented as one or more modules of instructions. A tangible program carrier may be a computer-readable medium. This computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, or a combination of one or more of these.

The term "processor" or "controller" may include all apparatus, devices and machines for processing data including, by way of example, programmable processors, computers or multiprocessors or multicomputers. In addition to hardware, the processor comprises code for creating an execution environment for the computer program in question, such as processor firmware, protocol stacks, database management systems, operating systems, or combinations of one or more of these. may contain code to

Computer programs (also known as programs, software, software applications, scripts or code) may be written in any form of programming language, including compiled or interpreted languages or declarative or procedural languages. , stand-alone programs or modules, components, subroutines or other units suitable for use in a computing environment. Computer programs do not necessarily correspond to files in a file system. A program can be part of another program or a file holding data (e.g., one or more scripts stored in a markup language document), a single file dedicated to that program, or multiple collaborative files (e.g. , a file containing one or more modules, subprograms or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes described herein may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. Processes and logic flows may be performed by dedicated logic circuits, such as FPGAs (Field Programmable Gate Arrays) or ASICs (Application Specific Integrated Circuits), to name a few, and devices may be implemented by such dedicated logic circuits. It may be implemented as a logic circuit.

Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor receives instructions and data from read-only memory and/or random-access memory. The essential elements of a computer are a processor for executing instructions and one or more data memory devices for storing instructions and data. Generally, a computer may include one or more mass storage devices, such as magnetic, magneto-optical, or optical disks, for storing data, receive data from, or receive data from, mass storage devices. It may be operatively connected to transfer data to the device or both. However, a computer need not have such a device. Additionally, the computer may be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), to name just a few examples.

Suitable computer-readable media for storing computer program instructions and data include, by way of example, semiconductor memory devices such as EPROM, EEPROM and flash memory devices, magnetic disks such as internal or removable disks, magneto-optical disks and CD ROMs. and all forms of data memory including non-volatile memory, media and memory devices including DVD-ROM discs. The processor and memory may be supplemented by dedicated logic circuitry or incorporated into dedicated logic circuitry.

To provide interaction with a user, the embodiments described herein use a display device, such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, and a display device for displaying information to the user. It may be implemented in a computer with a keyboard and pointing device, such as a mouse or trackball or touch screen, through which a user may provide input to the computer and the like. Also, other types of devices may be used to provide interaction with the user, e.g., input from the user may be received in any form including acoustic, speech or tactile input. .

Embodiments described herein may include a computing system including backend components, eg, data servers, or a computing system including middleware components, eg, application servers, or a computing system including middleware components, eg, application servers, or a user may or any combination of one or more such backend, middleware or frontend components as a client computer with a graphical user interface or web browser capable of interacting with the configuration of may be implemented in The components of the system can be interconnected by any form or medium of digital data communication, eg, a communication network. Embodiments of communication networks include local area networks (“LAN”) and wide area networks (“WAN”), such as the Internet.

The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs executing on the respective computers involving the interaction of client and server.

Although various embodiments have been described in detail with respect to specific illustrative examples thereof, it should be understood that the present disclosure is subject to numerous modifications and alterations of the disclosed features without departing from the scope of the following claims. Combinations are possible and should not be considered limited to such examples.

Hereinafter, preferred embodiments of the present invention will be described itemized.

Embodiment 1
A method for forming a glass ribbon, comprising:
moving the glass ribbon in the direction of travel along the travel path at a predetermined ribbon speed;
engaging the glass ribbon with an end effector attached to a robotic arm;
moving the end effector in the direction of travel at a first robot speed;
detecting the force exerted by the glass ribbon on the end effector;
changing the speed of the end effector from the first robot speed to a second robot speed when the magnitude of the force exceeds a predetermined value.

Embodiment 2
3. The method of embodiment 1, further comprising separating a first ribbon portion of the glass ribbon from a second ribbon portion of the glass ribbon prior to the step of varying speed.

Embodiment 3
3. The method of embodiment 2, further comprising engaging the second ribbon portion of the glass ribbon prior to changing the speed.

Embodiment 4
During the period between engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion, the speed of the end effector is reduced to the first 4. The method of any one of embodiments 2-3, further comprising maintaining a robot speed of .

Embodiment 5
5. The method of any one of embodiments 1-4, wherein the force is detected at multiple locations.

Embodiment 6
A method for forming a glass ribbon, comprising:
moving the glass ribbon in a traveling direction along a traveling path;
engaging a first ribbon portion of the glass ribbon with an end effector attached to a robotic arm;
during a first cycle of operation during the steps of engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion of the glass ribbon; moving an effector in the direction of travel at a first robot speed;
detecting a first force exerted by the first ribbon portion on the end effector during the first cycle of operation;
engaging the end effector with the second ribbon portion after the first cycle of operation;
varying the speed of the end effector from the first robot speed to a second robot speed based on the first force and moving the end effector at the second robot speed during a second motion cycle; and moving in the direction of travel.

Embodiment 7
7. The method of embodiment 6, further comprising separating the first ribbon portion from the second ribbon portion prior to engaging the second ribbon portion.

Embodiment 8
detecting a second force exerted by the second ribbon portion on the end effector during the second cycle of operation;
engaging the end effector with a third ribbon portion of the glass ribbon after the second cycle of operation;
During a third motion cycle, varying the speed of the end effector from the second robot speed to a third robot speed based on one or more of the first force or the second force. 8. The method of embodiment 7, further comprising: and moving the end effector in the direction of travel at the third robot speed.

Embodiment 9
the end effector through the first cycle of operation during the period from engaging the end effector with the first ribbon portion to separating the first ribbon portion from the second ribbon portion; 9. The method of embodiment 8, further comprising maintaining the speed of at the first robot speed.

Embodiment 10
10. The method of any one of embodiments 8-9, further comprising separating the second ribbon portion from the third ribbon portion prior to engaging the third ribbon portion. .

Embodiment 11
the end effector through the second cycle of operation during the period from engaging the end effector with the second ribbon portion to separating the second ribbon portion from the third ribbon portion; 11. The method of embodiment 10, further comprising maintaining the speed of at the second robot speed.

Embodiment 12
12. The method of any one of embodiments 6-11, wherein the first force is detected at multiple locations.

Embodiment 13
7. The method of embodiment 6, wherein changing the velocity is performed when the magnitude of the first force exceeds a predetermined value.

Embodiment 14
7. The method of embodiment 6, wherein the speed of the end effector is changed to the second robot speed before beginning the second motion cycle.

Embodiment 15
A method for forming a glass ribbon, comprising:
moving the glass ribbon in the direction of travel along the travel path at a predetermined ribbon speed;
engaging a first ribbon portion of the glass ribbon with an end effector attached to a robotic arm;
moving the end effector in the direction of travel at a predetermined robot speed;
detecting the force exerted by the first ribbon portion on the end effector;
quantifying the ribbon velocity by correlating the ribbon velocity to the robot velocity when the force magnitude is within a predetermined range of values;
and adjusting parameters of the glass ribbon based on the ribbon speed.

Embodiment 16
quantifying the ribbon velocity during a period from engaging the end effector with the first ribbon portion to separating the first ribbon portion from a second ribbon portion of the glass ribbon; 16. The method of embodiment 15, comprising determining an average ribbon speed of .

Embodiment 17
17. The method of embodiment 16, wherein adjusting the parameters comprises maintaining constant lengths of the first ribbon portion and the second ribbon portion.

Embodiment 18
16. The method of embodiment 15, wherein quantifying the ribbon velocity comprises determining an instantaneous ribbon velocity during a sampling period that is less than about 2 milliseconds.

Claims (15)

A method for forming a glass ribbon, comprising:
moving the glass ribbon in the direction of travel along the travel path at a predetermined ribbon speed;
engaging the glass ribbon with an end effector attached to a robotic arm;
moving the end effector in the direction of travel at a first robot speed;
detecting the force exerted by the glass ribbon on the end effector;
changing the speed of the end effector from the first robot speed to a second robot speed when the magnitude of the force exceeds a predetermined value. 2. The method of claim 1, further comprising separating a first ribbon portion of the glass ribbon from a second ribbon portion of the glass ribbon prior to the step of varying the speed. 3. The method of claim 2, further comprising engaging said second ribbon portion of said glass ribbon prior to said step of varying speed. During the period between engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion, the speed of the end effector is reduced to the first 4. The method of claim 2 or 3, further comprising maintaining a robot speed of . A method for forming a glass ribbon, comprising:
moving the glass ribbon in a traveling direction along a traveling path;
engaging a first ribbon portion of the glass ribbon with an end effector attached to a robotic arm;
during a first cycle of operation during the steps of engaging the end effector with the first ribbon portion and separating the first ribbon portion from the second ribbon portion of the glass ribbon; moving an effector in the direction of travel at a first robot speed;
detecting a first force exerted by the first ribbon portion on the end effector during the first cycle of operation;
engaging the end effector with the second ribbon portion after the first cycle of operation;
varying the speed of the end effector from the first robot speed to a second robot speed based on the first force and moving the end effector at the second robot speed during a second motion cycle; and moving in the direction of travel. 6. The method of claim 5, further comprising separating the first ribbon portion from the second ribbon portion prior to engaging the second ribbon portion. detecting a second force exerted by the second ribbon portion on the end effector during the second cycle of operation;
engaging the end effector with a third ribbon portion of the glass ribbon after the second cycle of operation;
During a third motion cycle, varying the speed of the end effector from the second robot speed to a third robot speed based on one or more of the first force or the second force. 7. The method of claim 6, further comprising: and moving the end effector in the direction of travel at the third robot speed. the end effector through the first cycle of operation during the period from engaging the end effector with the first ribbon portion to separating the first ribbon portion from the second ribbon portion; 8. The method of claim 7, further comprising maintaining said speed of at said first robot speed. 9. The method of claim 7 or 8, further comprising separating the second ribbon portion from the third ribbon portion prior to engaging the third ribbon portion. the end effector through the second cycle of operation during the period from engaging the end effector with the second ribbon portion to separating the second ribbon portion from the third ribbon portion; 10. The method of claim 9, further comprising maintaining said speed of at said second robot speed. 11. A method according to any one of claims 5 to 10, wherein the step of changing the speed is performed when the magnitude of the first force exceeds a predetermined value. 12. The method according to any one of claims 5 to 11, wherein the speed of the end effector is changed to the second robot speed before starting the second movement cycle. A method for forming a glass ribbon, comprising:
moving the glass ribbon in the direction of travel along the travel path at a predetermined ribbon speed;
engaging a first ribbon portion of the glass ribbon with an end effector attached to a robotic arm;
moving the end effector in the direction of travel at a predetermined robot speed;
detecting the force exerted by the first ribbon portion on the end effector;
quantifying the ribbon velocity by correlating the ribbon velocity to the robot velocity when the force magnitude is within a predetermined range of values;
and adjusting parameters of the glass ribbon based on the ribbon speed. quantifying the ribbon velocity during a period from engaging the end effector with the first ribbon portion to separating the first ribbon portion from a second ribbon portion of the glass ribbon; 14. The method of claim 13, comprising determining an average ribbon velocity of . 15. The method of claim 14, wherein adjusting the parameters comprises maintaining constant lengths of the first ribbon portion and the second ribbon portion.

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