EP2496417A1

EP2496417A1 - Method for controlling a control variable for a processing machine

Info

Publication number: EP2496417A1
Application number: EP10754435A
Authority: EP
Inventors: Stephan Schultze; Holger Schnabel
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2009-11-07
Filing date: 2010-09-16
Publication date: 2012-09-12
Anticipated expiration: 2030-09-16
Also published as: DE102009052330A1; WO2011054414A1; US20120282005A1; CN102666101A; EP2496417B1

Abstract

The invention relates to a method for controlling a control variable for a processing machine, in particular a printing machine (100), in particular a gravure printing machine, which has driven rollers (11l', 112', 113', 114', 121, 122, 123, 124) for transporting and/or for processing a material web (101), of which rollers at least one (121, 122, 123, 124) is not part of a clamping point (110, 111, 112, 113, 114, 115), wherein a first control element (121''', 122''', 123''', 124''') is pilot-operated based on a second control member (111'', 112'', 133'', 114'') according to a control value (uRl, uR2, uR3, uR4) in order to adjust the at least one driven roller (121, 122, 123, 124) that is not part of a clamping point (110, 111, 112, 113, 114, 115).

Description

Method for controlling a controlled variable in a processing machine

description

The present invention relates to a method for controlling a controlled variable in a processing machine and to a computing unit for carrying out the method.

Although reference will be made hereafter mainly to printing presses, the invention is not limited thereto but rather to all types of printing presses

Directed processing machines in which a web or web is processed. However, the invention is particularly applicable to printing machines, e.g. Newspaper printing machines, commercial printing machines, gravure printing machines, inline flexographic printing machines, packaging printing machines or securities printing machines, and in processing machines, such as printing machines. Bag machines,

Envelope machines or packaging machines, can be used. The web can be made of paper, cloth, cardboard, plastic, metal, rubber, in foil form etc.

be educated. State of the art

In processing machines, in particular printing machines, a web is moved along driven and non-driven rollers. The web is simultaneously processed by means of mostly driven processing devices, In the case of a processing machine, one or more processing registers (for example, longitudinal registers, side registers) and / or the web tension are usually regulated in the state of the art.- A driven roller may belong to a clamping point which causes the Web trapped positively or non-positively and therefore can impress a web tension in the web. In a printing machine, a KJemmstelle example of a printing unit in which a frictional unit between the driven pressure cylinder, the impression roller and the material web is formed formed.

The web can be divided into web tension sections, wherein a

Web tension section is limited by two terminal points. Within a web tension section further driven and / or non-driven rollers may be arranged. Often the entire web is in several

Web tension sections, sometimes with different

Web tension setpoints, divided. To maintain the setpoints usually a web tension control is used.

In the prior art, it is customary to set the register of a processing unit and / or the web tension of a web tension section by appropriate actuation of actuators, such as pressure cylinders or their drives, transport rollers or their drives, compensators and the like. Due to the coupling of the individual actuators to one another via the material web, such settings continue to propagate as disturbances and must be compensated at subsequent processing units and / or web tension sections by the associated controllers. In the prior art possibilities are described to decouple such settings, ie to leave the register of other processing plants or the web tension of other web tension sections unaffected during an adjustment. In DE 103 35 885 AI a combined register and web tension control is disclosed. To decouple the register of web tension adjustment operations, an upstream strategy for web tension control is proposed. In DE 10 2007 017 096 AI is described in a downstream control by means of a (dynamic) downstream feedforward all subsequent

Clamp points so vorzusteuem that they directly compensate for the effects of the leading KJemmstelle. As a result, it is ensured that all subsequent register controllers do not have to compensate for the disturbances of the coupling through the material web.

In the non-prepublished DE 10 2008 056 132 a decoupling for upstream control is proposed, wherein in addition to a (constant) upstream feedforward also a (dynamic) downstream feedforward control is performed by means of PT1 -Glied.

However, the previous Entkoppelmethoden do not allow for all structural

Conditions expect the same good results. In particular, processing machines with driven rollers, which do not form a nip, are not sufficiently considered.

It is therefore desirable to have an improved control method for

Machine tools with driven rollers, which do not form a nip specify.

Disclosure of the invention

According to the invention, a method for controlling a controlled variable in a processing machine having the features of claim 1 and a Arithmetic unit proposed for carrying out this method. advantageous

Embodiments are the subject of the dependent claims and the following

Description. Advantages of the invention

In addition to the previously mentioned processing and transport rollers exist in

Machine tools also other - typically massive - rollers with their own drives. For example, from DE 10 2006 _. 047 846 AI known to drive cooling and / or guide rollers to improve the register accuracy. Since these other rolls neither form nipples nor perform a register-based processing of the material, they are not taken into account in known decoupling strategies. However, it has been recognized that these rollers still adversely affect the decoupling. It has been found that inclusion of these rollers in the decoupling strategy, for example. By a precontrol depending on the

decisive control value, leads to a significant improvement in decoupling. The integration is expediently carried out in the known strategies

(Upstream or Downstream if necessary in combination with Standfarben- or

Precursor color control). The pilot control is expediently carried out in the regulation of a processing register and / or a web tension. The driven roller is the first actuator depending on the adjustment

(decisive control value) of a second actuator pilot-operated.

In an embodiment, the pilot control takes place during the acceleration phase, for example, the startup of the machine. Friction occurs between the processing roll and the driven roll, typically by other non-driven rolls, such as the like. Guide rollers. This friction leads to a stationary control deviation. Furthermore, the non-driven rollers have a moment of inertia, which at

Speed changes must be overcome. This leads to a dynamic deviation. In order not to allow these influences to be compensated for only after the occurrence of the control deviation by the controller, the at least one driven roller can be correspondingly pre-controlled in the event of a speed change.

The precontrol can take place model-based and / or adaptive-in particular in the case of a speed change. Model based means that off

physical quantities, e.g. Web speed, format, modulus, inertias, friction, acceleration, etc., the corresponding pilot size is calculated. Adaptive means that the pre-tax amount after each

Acceleration phase is optimized. In particular, one offers

Learning algorithm that observes the pilot control quantity (e.g., the manipulated variable to the drive of the roller) during a speed change based on a still occurring control deviation and thus automatically adapts to changing production conditions (e.g., ambient temperature change, humidity, dryer temperature, etc.).

Appropriately, a slip and / or expansion slip is taken into account in the precontrol. Since the rollers are not part of a nip and they are wrapped only by the web, at high speeds an air film between roller and web can form and reduce the detention zone as a result. This can lead to a feedforward control of the roller no longer completely affecting the material web. It thus no longer comes to a complete decoupling of the adjustment because no complete

Power transfer from the chill roll to the web takes place more.

Advantageously, the sliding slip that occurs is correspondingly taken into account in the pilot control, so that, for example, as the transmission of power decreases, the precontrol is increased. In an embodiment, the at least one driven roller is controlled and at least a third actuator in response to the control value for the first actuator piloted. If the driven roller itself is integrated in a control system, this control valve generates its own control values, which in turn are generated by -

Decoupling network processed accordingly - used to precontrol other actuators to improve the decoupling.

An arithmetic unit according to the invention, e.g. a control unit of a printing press, is, in particular programmatically, adapted to perform a method according to the invention.

Also, the implementation of the invention in the form of software is advantageous because this allows very low cost, especially if an executing

Arithmetic unit is still used for other tasks and therefore already exists. Suitable media for providing the computer program are

especially floppy disks, hard disks, flash memories, EEPROMs, CD-ROMs, DVDs and the like. It is also possible to download a program via computer networks (Internet, intranet, etc.). Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention. The invention is illustrated schematically with reference to an exemplary embodiment in the drawing and will be described in detail below with reference to the drawing.

figure description

Figure 1 shows a schematic representation of a designed as a printing machine processing machine with self-propelled cooling rollers.

Figure 2 shows a schematic representation of an example of a

Control strategy according to the invention for a printing machine according to FIG. 1.

In FIG. 1, a processing machine designed as a printing machine, as may be the basis of the present invention, is shown schematically and designated 100 as a whole. A printing material, for example, paper 101, the machine via a feed train 1 10 is supplied. The paper 101 is guided and printed by as printing units 1 1 1, 1 12, 1 13, 1 14 trained processing facilities and output by a pull-out 1 15 again. The input, extraction and printing units 1 10 to 1 15 are positionable, in particular cylinder or angle correctable arranged. The printing units 1 11 to 1 14 are in a web tension-controlled area between the intake unit 1 10 and the pultrusion 1 15th

The printing units 1 1 1 to 1 14 each have a printing cylinder 1 1 to 1 14 ', against which a respective impression roller 1 1 1 "to 1 14" is employed with strong pressure. The impression cylinders 11 to 1 14 'are driven individually and independently. The associated drives III '"to 1 14"' are shown schematically. The impression rollers 1 1 1 "to 1 14" are freely rotatable. The feed and pull-out unit 1 10 or 1 15 has two opposing cylinders which guide the paper 101. Also ever a transport roller of the intake and the extension mechanism is individually driven by a drive 1 10 '"or 1 15'". The feeder and pull-out unit 1 10, 1 15 and the printing units 1 1 1 to 1 14 each form a nip. In the web sections between the individual printing units 1 1 1 to 1 14, the paper 101 is guided over unspecified explained roles, which are designated 102. For reasons of clarity, not all rollers are provided with reference numeral 102. It may in particular be pulleys, drying, trimming equipment, etc.

Often located between the printing units 1 1 1 to 1 14 and the corresponding cooling rollers each have a dryer that dries the printed on the web 101 color. The web 101 is guided by a printing and possibly drying step over cooling rollers. For this purpose, in the web section between the first printing unit 1 1 1 and the second printing unit 1 12, a cooling roller 121, in the section between the second printing unit 1 12 and the third printing unit 1 13 a cooling roller 122, in the section between the third printing unit 113 and the fourth Printing unit 114, a cooling roller 123 and in the section between the fourth printing unit 1 14 and the pultrusion 1 15th a fourth cooling roll 124 is arranged. According to the illustrated embodiment of the printing machine, all the cooling rollers 121 to 124 are self-propelled and equipped with their own drives 12 "to 124" '. In other machine types or

Printing applications may also have the driven rollers 121 to 124, for example, temperature-increasing (heating rollers) or other functions. With reference to Figure 2 describes how the self-propelled cooling rollers are included in a web tension and / or register control in the illustrated printing machine. It will be understood that the manner described is also valid for other self-propelled rollers. FIG. 2 shows a downstream rule strategy with decoupling using the example of the printing press according to FIG. 1 however, only the elements essential to the example are shown in FIG. 2. Downstream means that adjustments are made in web direction. If an actuator i (for example, a pressure cylinder) to be adjusted, the actuator i is adjusted itself. Upstream means that an adjustment is made against the direction of web travel. If the actuator i is to be adjusted, all the actuators in front of it (usually including the feeder) 1, 2, i-1 are adjusted, but the actuator i is left unchanged. It is known

To decouple in both strategies also all subsequent actuators i + 1, i + 2, n to adjust.

In a controller (not shown) manipulated variables (controller output variables) uRl, uR2, uR3 and uR4 for the drives 1 1 Γ "to 1 14" 'of the printing units 1 1 1 to 1 14 are determined. The manipulated variables may be, for example, to control the web tension

Rotation speeds, fine adjustments and the like act. In the regulation of

Register is the manipulated variable, for example, an angle offset and the like. The manipulated variables are processed by a decoupling network 200 and provided as modified manipulated variables ul, u2, u3 and u4 to the drives. The decoupling network 200 includes rule members 201-203 and 21 1-213. Furthermore, the decoupling network 200 provides manipulated variables uVl, uV2, uV3 for the drives of the cooling rollers.

The rule members 201 -203 are used for downstream decoupling of the printing units of a positioning movement. The control elements 21 1-213 are used for downstream decoupling of the driven cooling rollers and cause a feedforward control in response to a manipulated variable. The actual configuration of the precontrol is generally dependent on the control strategy (predecessor color or reference color) and the adjustment direction (downstream or upstream). The control elements 21 1 -213 represent corresponding dynamic decoupling strategies. For example, a feedforward control can take place in a downstream predecessor color control via a combination of a DT1 element and a dead time. The time constants of the control elements are Depending on the material web length, here on the one hand from printing unit to cooling roller and on the other hand from the cooling roller to printing unit, and the web speed. For example, in an adjustment of the drive 1 1 1 ^* "based on a manipulated variable uRl this unchanged to the drive and additionally via the control member 21 1, which takes into account the web length between roller 1 1 1 'and roller 121, and the control member 201, which takes into account the web length between roller 121 and roller 1 12 ', is precontrolled to the following actuators, wherein the pilot control variable and the manipulated variables uVl, u2, uV2, u3, uV3, u4 are received. In the present example, the cooling rollers are not regulated; none

Actuating variables (controller output variables) are provided for the cooling rolls. Optionally, the cooling rollers could also be controlled in addition to the pilot control. The associated manipulated variable for a chill roll would expediently decoupled in this case as well as the manipulated variables for the printing cylinder dynamically. The decoupling is expediently carried out by means of dynamic timers. These can be, for example, PT1, PT2, PTn, DT1, DT2, DTn links, dead times, etc. Furthermore, non-linear precontrol systems, which have similar characteristics as the dynamic timers, are also permissible.

Claims

Claims 1. A method for controlling a controlled variable in a processing machine, in particular a printing press (100), in particular a gravure printing press, the rollers (1 1 1 ', 1 12', 1 13 'driven for transporting and / or processing a web (101) , 1 14 ', 121, 122, 123, 124), of which at least one (121, 122, 123, 124) not part of a clamping point (1 10, 1 1 1, 1 12, 1 13, 1 14, 1 15), wherein a first actuator (121 "', 122"', 123 "', 124"') for adjusting the at least one driven roller (121, 122, 123, 124), which is not part of a nip (10 , 1 1 1, 1 12, 113, 1 14, 1 15), depending on a control value (uRl, uR2, uR3, uR4) to a second actuator (1 11 "', 1 12"', 1 13 " ', 1 14' ") is piloted.

2. The method of claim 1, wherein the at least one driven roller is formed as a cooling / heating (121, 122, 123, 124) or guide roller,

3. The method according to claim 1 or 2, wherein a second actuator

Processing, transport, cooling, heating and / or guide roller roller or its drive (I I I '", 1 12"', 1 13 "', 1 14'") is used.

4. The method according to any one of the preceding claims, wherein the second actuator is a compensator.

5. The method according to any one of the preceding claims, wherein the controlled variable is a processing register and / or a web tension.

6. The method according to any one of the preceding claims, wherein the precontrol is model-based and / or adaptive.

7. The method according to any one of the preceding claims, wherein in the feedforward a sliding and / or Dehnschlupf the at least one driven roller (121, 122,

123, 124) is taken into account.

8. The method according to any one of the preceding claims, wherein the pre-control is stationary and / or dynamic for different speed conditions.

9. The method according to any one of the preceding claims, wherein the at least one driven roller is controlled and at least a third actuator in response to the control value for the first actuator is piloted.

10. Arithmetic unit which is adapted to perform a method according to one of the preceding claims.