KR101203162B1 - Method of controlling roll-to-roll printing process using adaptive simulation - Google Patents

Abstract

PURPOSE: A method for controlling a roll-to-roll printing process adapting an adaptive simulation is provided to reflect a result in which details or a whole of a roll-to-roll process is modeled as formulas to a controller and a control algorithm and to feed-back various kinds of process values of a production process on a real time basis, thereby proving and improving the model and algorithm. CONSTITUTION: A method for controlling a roll-to-roll printing process adapting an adaptive simulation comprises next steps. A numerical model of a roll-to-roll continuous process printing system is set(S101). A controller is designed based on the numerical model(S102). The roll-to-roll printing process is simulated by using the controller and numerical model(S103). The roll-to-roll continuous process printing system is driven by the controller(S113). An output value of a simulation state of the roll-to-roll printing process is output(S114). An output value of a driving state of the roll-to-roll printing process is output. An error is calculated by comparing the output values of the simulation state and driving state. When the calculated error is a set-up value or greater, the numerical model is reset by correcting a system variable. The controller is tuned based on the reset numerical model. [Reference numerals] (AA) Start; (BB) No; (CC) Yes; (DD) Finish; (S101) Setting a numerical model and system; (S102) Designing/tuning a controller; (S103) Simulation; (S104) State output; (S113) R2R device operation; (S114) State output; (S120) Lower than an error?

Description

Roll-to-roll printing process control method using adaptive simulation {METHOD OF CONTROLLING ROLL-TO-ROLL PRINTING PROCESS USING ADAPTIVE SIMULATION}

The present invention relates to a roll-to-roll printing process, and more particularly to a roll-to-roll printing process control method that can control the overlapping accuracy of the web.

The roll-to-roll process is the process of printing a web that is very large in width and length compared to its thickness, such as plastic film or paper, from unwinder to rewinder. It is a process that applies various production techniques such as printing, coating and patterning.

This process has traditionally been used for film production and media printing. It is also applied to the production of printed electronic devices such as RFID tags, thin film solar cells, supercapacitors, thin film transistors, thin film lighting, and flexible displays. Conventional roll-to-roll processes have been used for media printing such as newspapers and magazines, and for the production of textiles and films. Therefore, registration registration was at least several tens of micrometers, .

In the past, modeling of a part of the production process as a method to improve the superposition precision, after designing the controller and control algorithm through simulation, numerical values related to the production process (for example, web tension, transport velocity, registration, etc.) and feedback control method using the same have been used. However, if the simulation results show that the controller and algorithm are designed without validation and improvement in real-time simulations, and that the collected numerical values are used to control the production tolerance of the component parts There has been an error between the actual and the simulation due to the controller design after the simulation without considering the simulation results.

Based on the technical background as described above, the present invention reflects the results of modeling the details or the whole of the roll-to-roll process in the design of the controller and the control algorithm, and feeds back various process values of the production process in real time to provide the model and algorithm. It is an object of the present invention to provide a roll-to-roll printing process control method that can be proved and developed.

Roll to roll printing process control method according to an embodiment of the present invention, the numerical model setting step of setting the numerical model of the roll-to-roll continuous process printing system; A controller design step of designing a controller based on the numerical model; A simulation step of simulating the roll-to-roll printing process using the controller and the numerical model; A system driving step of driving the roll-to-roll continuous process printing system by the controller; Outputting a simulation state output value of the roll-to-roll printing process; Outputting a drive state output value of the roll-to-roll continuous process printing system; A state output comparing step of calculating an error by comparing the simulation state output value with the driving state output value; A numerical model resetting step of resetting the numerical model by modifying a system variable in the numerical model setting step of the roll-to-roll continuous process printing system when the error calculated in the state output comparing step is equal to or greater than a set value; And a controller tuning step of tuning the controller based on the reset numerical model, wherein the tuned controller restarts the roll-to-roll continuous process printing system and restarts the simulation based on the reset numerical model. Do it.

According to the control method of the roll-to-roll printing process as described above, the model and algorithm are applied by reflecting the result of modeling the detail or the whole of the roll-to-roll process by the formula to the controller and the control algorithm design and feeding back various process values of the production process in real time. It can prove and develop and improve nesting precision.

In addition, the system model (S / W) can be intelligently evolved according to the actual equipment through iteration, and the model obtained at this time can understand and predict the driving characteristics of the equipment. In this case, mechanical errors related to production tolerances may be reflected in the process model.

And by using the model proved by real equipment, it is possible to design the controller optimized for superposition precision control. After that, it is possible to predict the process result by using the numerical value actually obtained by using the proven simulation model. Using this proven model, various control software algorithms can be tested in advance in software, which shortens the development period.

1 is a schematic view showing a roll-to-roll continuous process printing system according to an embodiment of the present invention.
2 is a flowchart illustrating a method for controlling a roll-to-roll printing process according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a schematic view showing a roll-to-roll continuous process printing system according to an embodiment of the present invention.

Referring to FIG. 1, a roll-to-roll continuous process printing system 100 according to the present embodiment includes an unwinder 10 and a rewinder 40, between which a web 15 . The unwinder 10 is a roll for winding and unwinding and supplying the web 15, and the rewinder 40 is a roll for rewinding and recovering the web 15.

Between the unwinder 10 and the rewinder 40, drive rolls 20, 30, tension rolls 16, 26, 36, and dancers 28 that rotate in contact with the web 15 are located. The image sensor 35 may be installed to approach the web 15 to be transferred. The driving rolls 20 and 30 serve to provide a driving force to the web 15, and the tension rolls 16, 26 and 36 measure a tension of the web 15, and the dancer 28. ) Serves to control the tension of the web 15. The image sensor 35 checks an image of the web 15 to be transferred to detect overlapping precision and speed.

The controller 50 is connected to the unwinder 10, the driving rolls 20 and 30, the dancers 28, and the rewinder 40, and transmits control signals in their respective configurations. You can also receive a drive output. That is, the controller 50 rotates the phase of the motor in each of the driving motors (not shown) for driving the unwinder 10, the driving rolls 20, 30, and the rewinder 40, and the rotational speed of the motor. The controller may transmit a control signal for controlling the rotation acceleration of the motor, and may receive a driving output value output as a result of the driving of the driving motors driven based on the control signal. In addition, the controller 50 may transmit a control signal for controlling the position of the dancer, the speed of the dancer, the acceleration of the dancer, and the like to a driving motor (not shown) or an actuator (not shown) for driving the dancer 28. In addition, a driving output value output as a result of the driving of the driving motor or the actuator of the dancer 28 operating based on the control signal may be received.

On the other hand, the controller 50 is connected to the tension rolls 16, 26, 36 and the image sensor 35 may receive a state output value from each of these components. That is, a load cell (not shown) is attached to the tension rolls 16, 26 and 36 to measure the tension of the web, and the measured state output value of the web can be transmitted to the controller 50 have. In addition, the image sensor 35 may detect a web transport velocity or an overlapping precision using an image of the web 15 being transported, and may detect the web conveying speed or the overlapping precision state output value. May be transmitted to the controller 50.

2 is a flowchart illustrating a method for controlling a roll-to-roll printing process according to an embodiment of the present invention.

The roll-to-roll printing process control method according to the present embodiment may be applied in a process of performing a roll-to-roll printing process by driving a roll-to-roll continuous process printing system, and may include the following steps.

First, numerical models of the roll-to-roll continuous process printing system are set (S101).

The numerical model includes web longitudinal dynamics model, web lateral dynamics model, printed feature drying / sintering model, roll printing model, coating At least one of a model, a patterning model, and a registration dynamics model.

In the printed object drying and curing model, hot air drying, UV (Ultraviolet) drying, NIR (Near Infrared) drying, IR (Infrared) drying, IPL (Intense Pulsed Light) drying, and laser drying are selectively included according to the characteristics of the substrate. can do.

In the roll type printing model, gravure printing, gravure offset printing, reverse gravure offset printing, and the like may be selectively included according to the purpose of the printed matter and the characteristics of the printed object. .

In the coating model, a coating process such as slot-die coating and reverse gravure coating may be selectively included according to the purpose and characteristics of the printed object.

The patterning model may include an imprinting process.

Next, the controller 50 is designed based on the numerical model (S102).

The controller is a proportional-integral-derivative (PID) controller, and can be designed by setting a gain value of the controller. Alternatively, it may be tuned using a fuzzy control logic technique.

The control area of the controller may be set differently according to each control target. That is, in the case of controlling the motor of the unwinder, the rewinder, and the driving roll, the control region may include a rotational phase of the motor, a rotational speed of the motor, and a rotational acceleration of the motor. When controlling the dancer, the control region may include the position of the dancer, the speed of the dancer, and the acceleration of the dancer.

When the roll-to-roll continuous process printing system includes a print stage and a controller is connected to and controls the print stage, the control area includes a transverse position of the print stage, a transverse movement speed of the print stage, and a transverse acceleration of the print stage. It may include. In addition, when the roll-to-roll continuous process printing system includes a web guide unit and a controller is connected to and controls the web guide unit, the control area includes the rotation amount of the web guide unit, the rotation speed of the web guide unit, the web guide unit. It may include rotational acceleration.

When designing the controller, it is necessary to confirm whether the system to be controlled is a controllable stable system. If the system is not stabilized (unstable system), only the controllable region can run simulation and device driving to enter model verification.

Meanwhile, when designing the controller, it is necessary to control the roll-to-roll printing process within a required time constant.

Next, the roll-to-roll printing process is simulated using the controller and the numerical model (S103). Then, the roll-to-roll continuous process printing system is driven by the controller (S113).

Next, the simulation state output value of the roll-to-roll printing process is output (S104). And outputs the drive state output value of the roll-to-roll continuous process printing system (S114).

The simulated state output value of the roll-to-roll printing process and the drive state output value of the roll-to-roll continuous process printing system include at least one of tension, web velocity, and regulation.

The tension may be measured using a load cell mounted on the tension roll, and the measured tension value may be transmitted to the controller. The web speed may be measured using the image sensor and encoder, and the measured web speed value may be transmitted to the controller. The overlapping precision may also be measured using an image sensor, and the measured overlapping precision value may be transmitted to the controller.

Next, a state output comparison step of calculating an error by comparing the simulation state output value with the driving state output value is performed (S120).

The simulation state output value of the roll-to-roll printing process and the driving state output value of the roll-to-roll continuous process printing system calculated in the state output comparing step are output values of the same kind.

The comparison of the state output values is performed in a steady state and a transient behavior period, and the time domain response can be checked for each component of the system. That is, both the state output value and the transient behavior state output value are compared when the change value over time is stabilized (when the transient period is over and the dy / dt value approaches zero in the steady state) after the system is driven.

The reason for comparing the state outputs of transient behavior as well as the stabilization interval is that the simulation model includes parameters that affect system dynamics. By accurately predicting the transient behavior, the controller can be designed for precise state control.

Next, when the error calculated in the state output comparison step is greater than or equal to a set value, in the numerical model setting step (S101) of the roll-to-roll continuous process printing system, the numerical model is modified to reset the numerical model.

The numerical model also includes system parameters such as roller diameter, roller eccentricity, axle inertia, motor response time, substrate thickness, substrate modulus, substrate viscosity, and substrate thermal expansion coefficient. substrate coefficient of thermal expansion).

When the difference between the simulation state output value and the driving state output value of the printing system falls below a set value or a set percentage, it may be determined that the simulation simulates the actual system, and the numerical model is verified. Will be.

The controller is tuned in the controller design step S102 based on the reset numerical model. In the controller tuning step, the gain value of the controller may be reset and tuned.

The tuned controller restarts the roll-to-roll continuous process printing system and re-runs the simulation based on the reset numerical model.

That is, the numerical model setting step or the controller tuning step may be repeated one or more times according to the error calculation result of the simulation state output value and the driving state output value. This allows the numerical model of the roll-to-roll continuous process printing system to be set to approximate the actual system.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

S101: Numerical model setting step S102: Controller design step
S103: simulation step S104: simulation status output step
S113: System driving step S114: System status output step
S120: status output comparison step
10: Unwind 15: Web
16, 26, 36: tension roll 20, 30: driving roll
23, 33: dryer 28: dancer
35: image sensor 40: rewinder
50: controller 100: roll-to-roll continuous process printing system

Claims (8)

In the method of controlling the roll-to-roll printing process when the roll-to-roll continuous process printing system for performing a roll-to-roll printing process,
A numerical model setting step of setting a numerical model of the roll-to-roll continuous process printing system;
A controller design step of designing a controller based on the numerical model;
A simulation step of simulating the roll-to-roll printing process using the controller and the numerical model;
A system driving step of driving the roll-to-roll continuous process printing system by the controller;
Outputting a simulation state output value of the roll-to-roll printing process;
Outputting a drive state output value of the roll-to-roll continuous process printing system;
A state output comparing step of calculating an error by comparing the simulation state output value with the driving state output value;
A numerical model resetting step of resetting the numerical model by modifying a system variable in the numerical model setting step of the roll-to-roll continuous process printing system when the error calculated in the state output comparing step is equal to or greater than a set value; And
A controller tuning step of tuning the controller based on the reset numerical model
Including,
Restarting the roll-to-roll continuous process printing system by the tuned controller and rerunning the simulation based on the reset numerical model;
Roll-to-roll printing process control method for repeating the numerical model setting step to the controller tuning step one or more times. The method of claim 1,
The numerical model may include at least one of a web feed model, a web meandering model, a printed object drying and curing model, a roll type printing model, a coating model, a patterning model, and an overlapping precision model. The method of claim 1,
The numerical model of the roll-to-roll continuous printing system is a system variable such as roller diameter, roller eccentricity, axle inertia, motor response time, substrate thickness, substrate modulus, substrate viscosity. ), A method of controlling a roll-to-roll printing process comprising at least one of a substrate coefficient of thermal expansion. The method of claim 1,
The controller is a proportional-integral-derivative (PID) controller,
Roll-to-roll printing process control method for setting and tuning each gain value of the controller in the controller design step and the controller tuning step. The method of claim 1,
The simulation state output value of the roll-to-roll printing process and the driving state output value of the roll-to-roll continuous process printing system may include at least one of tension, web velocity, and overlap precision. Way. The method of claim 1,
And a simulation state output value of the roll-to-roll printing process and the driving state output value of the roll-to-roll continuous process printing system calculated in the state output comparing step are output values of the same kind. delete The method of claim 1,
The roll-to-roll continuous process printing system,
An unwinder that winds, unwinds and supplies the web;
A rewinder for rewinding and rewinding the web;
A driving roll providing a driving force while rotating in contact with the web between the unwinder and the rewinder;
A tension roll configured to detect a tension of the web while rotating in contact with the web between the unwinder and the rewinder;
A dancer controlling the tension of the web while rotating in contact with the web between the unwinder and the rewinder;
An image sensor installed close to the web transported between the unwinder and the rewinder to detect overlapping precision and speed
Roll to roll printing process control method comprising a.

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