EP0882587A1 - Controlling register of printing cylinders in a rotary web printing machine - Google Patents

Abstract

A first cylinder (11) printing on one side of the web and a second cylinder (12) printing on the same side are driven by two motors (10). The angular position of the second cylinder is matched with the first through a regulator (30,32). When changing a production condition at least one regulator parameter of the regulator is changed and the regulator setting is thereby adapted to the production requirement. The parameter foundation value is changed at most twice during production but is preferably constant. At least one regulator parameter can be changed conforming with the speed of one of the cylinders pressing on the same web side.

Description

The invention relates to a method and a device for registering Alignment of cylinders of a web press on a web according to the preambles of claim 1 and claim 16.

In rotary printing, the ability plays as quickly and with little waste as possible being able to switch from one production to the next is a growing role. Newspapers and magazines are increasingly tailored to local needs or specific ones Target groups tailored so that the number of editions increases, the scope of the individual editions, however, decreases. The importance of changes in production in terms of on the profitability of the printing press grows.

Concepts for flexibly configurable printing machines that also help In spite of increased flexibility, the acquisition costs are kept low from EP 0 644 048 A2 known to the applicant. The concepts described there individually driven pressure points for rubber / rubber and steel / rubber production allow a flying plate change with continuous production. Here are when production is running in this production, press on and unneeded printing cylinders ramped up and when a predetermined peripheral speed is reached Impression cylinder created so that the new pressure points for the subsequent Production to be formed. The new pressure points or pressure gaps between two cylinders printing on the web, i.e. Printing cylinders that are formed lie on the way of the web of the still running production. The train doesn't have to be new to be confiscated. Cylinders of pressure points that are no longer required ongoing production are swung away. The new production starts and closes seamlessly follows the previous one. With these well-known printing machines and Printing machine concepts, it is no longer necessary to press the machine Bring production change to a standstill and come to a standstill again ramp up so that the changeover times are reduced considerably, ideally to zero, can be.

With the flying plate change, for example with web width changes, and the flying production change that this enables in most cases first the peripheral speed of the impression cylinder for the previous old one Production up to a predetermined value, for example 30% of the Speed in production, lowered, and the new cylinders are made for the subsequent new production after reaching the same peripheral speed created their counter cylinders. The new production is going at this speed added. Then the cylinders that now form the pressure points are opened the speed of the production run increased. When changing production in this example, drive through two speed ramps. The Drive concept of those described in the above-mentioned publications Printing machines with individually driven printing units also allow compared to the previously common drives with a common shaft faster travel through the speed ramps, so that the changeover times can be shortened again between two productions.

The invention has set itself the task of keeping the register and thus the To improve the quality of the printed image on a printing web.

This object is solved by the subject matter of claims 1 and 16.

The invention relates to web-fed rotary printing presses, in particular for the Newspaper offset printing, as known for example from EP 0 644 048 A2 are. A first cylinder printing on one side of a web is replaced by a first The engine and a second cylinder printing on the same side of the web are driven by driven by a second motor, i.e. between the first and second cylinders there is no mechanical coupling for a common drive by one common engine. The two motors are not form-fitting for drive purposes connected. At least one of the two cylinders is kept in register regulated another cylinder. Preferably, both engines are related to the Angular position of the cylinders driven by them regulated.

In a method according to the invention for tuning the first in register and the second cylinder becomes the control behavior of at least the register controller specifically changed for the second cylinder if one the circumferential register influencing change in a production condition is made. The A change in the control behavior is achieved by deliberately changing at least one Controller parameters. Changes in production conditions that an inventive Trigger changes in the control behavior are such changes, their impact on the circumferential register or the accuracy of the register is predictable and are reproducible. This includes in particular a change in the length of the web between two neighboring printing units and possibly also to the Register recording sensors as a result of reshaping of pressure points and / or a change in the web speed, for example in the run-up and run-down phases the machine and / or a change in paper quality due to a roll change and / or a change in the ink / moisture supply.

The inventive answer to one or more changes in production conditions consists in an adapted change in the control behavior of the Controller, namely a controlled adaptation of at least one controller parameter, possibly all or at least all essential controller parameters. The Adjustment of the controller is the changed situation in real time or anticipating preferably adapted in part in real time and in part anticipating. As The circumferential speed preferably flows into the formation of the controller parameter in real time or the speed of the cylinder to be adjusted in register. However, the circumferential speed of one of the others can also be used instead Cylinders are used that are in register with the second cylinder are, for example that of a reference cylinder.

Changed train paths and thereby changed ones are particularly anticipatory Path lengths are taken into account by setting basic parameters when changing production be imported.

In a device according to the invention for register-based tuning at least the register controller for the second to be matched to the first cylinder Cylinder via a preferably digital signal processor, with its own Memory in which the basic parameter values for the controller parameters of this controller stored or in which the respectively valid basic parameter values can be written. The circuit or signal processor of the controller must be used when using a Read only memory which of these stored basic values for the current operating case should apply to the respective controller parameter. In In one embodiment, the controller itself has both a RAM and a ROM and receives from a higher-level control system only via a control signal the message as to which of the values or data records stored in the controller's ROM take it over to its RAM and use it until further notice. The current one The set of values for the controller parameters can, however, also advantageously be provided by the higher-level Controller can be loaded directly into a RAM of the controller.

In order to keep the waste as low as possible or to drive it without waste in a development of the invention, the engine controller of the engine for the second Cylinder a disturbance variable. Due to the additional disturbance variable such larger deviations in the circumferential register, i.e. Register errors or Register deviations, counteracted without such additional activation and would occur without register regulation. The disturbance variable is preferably the Cylinder peripheral speed or a quantity from which the peripheral speed can be determined used. The peripheral speed or the equivalent size is preferably measured on and each of the cylinders Cylinder switched on or representative of all of the one another in register cylinders to be matched measured on one of these cylinders and each of the others Cylinder activated. From this, a control element forms on the basis of a stored, speed-dependent characteristic curve a disturbance variable component to be switched on.

Thus, the angular position of the cylinders is traditionally synchronous Runs controlled and regulated, but the random and the are not taken into account predictable change in web behavior during operation. For example the train, among other things, a function of the speed of the train. Such, in particular, changes in web behavior that occur during transient operation, that cause intolerable registration errors are caused by the invention additional connection of a disturbance variable to the manipulated variable of the register controller or directly compensated for the reference variable for a motor controller or not even approved from the start. Each of the motors is therefore based on the conventional guide variable, for example the absolute angular position. At least the engine for the cylinder to be tuned is also switched on based on the additional Disturbance variable to compensate for a predictably changing path behavior guided.

In conjunction with the controlled adaptation of a register, the register is maintained promoted in a synergistic manner by switching on the disturbance variable. After an alternative embodiment of the invention can even be based on a register regulation of the second cylinder and, if necessary, further ones to be tuned in register Cylinders can be dispensed with entirely. The engine governor for the cylinder is in such phases only by means of a guide variable and the additional disturbance variable controlled.

At discrete times or continuously, especially when going through Speed ramps, disturbance to be applied can be empirical or by Simulation or a combined method can be determined.

In an empirical method, all of the Drive through possible predictable speed ramps later in operation. The one there generated print copies can be laid out and the registration marks measured will. The speed ramps are traversed in steps, in such a way that at predetermined times of an acceleration or deceleration phase at the cylinder circumferential speed just reached in the production passed and the printed registration marks measured and evaluated will. This is done on every step of the speed ramp. Out In the evaluation, discrete values for register errors or register deviations become received and from this the values for the additional disturbance variable to be applied are determined, with which the registration error, which would otherwise occur without the disturbance variable being applied, is compensated. Between the discrete ones obtained by this type of measurement Values for the register deviation can be interpolated and thus a continuous, preferably a continuous course of the register deviation over the circumferential cylinder speed be preserved. However, the disturbance variable can also be in discrete Steps are activated.

With an empirical method, those in the machine are advantageously used existing color register measuring devices for automatic measurement for this purpose utilized.

In later operation, the empirically found connection when driving through used by speed ramps to apply the disturbance variable.

A particularly suitable method for determining the registration error in connection with a brand that is also particularly suitable for the invention, with which it can be found under others the registration error can be determined, is in the German patent application no. 196 39 014.1 of the applicant, the disclosure of which for the purposes of Invention is hereby incorporated by reference.

In a further advantageous embodiment of the invention, a third Partial controlled system comprising cylinders, from one comprising the second cylinder Partial controlled system decoupled with respect to the circumferential register. The third cylinder prints on the same side of the track as the first and second cylinders and follows in Web direction seen the second cylinder.

The first prints in a multicolor printing machine which is preferably used as the basis Cylinder is the reference color, and the second and third cylinders are kept in register tuned with respect to the first cylinder. By decoupling in Register controllers become cylinder position adjustments of the previous cylinder or cylinders passed on to the controller of the third cylinder as a change in cylinder position, that influencing the web tension by one at the second or also with the first and second cylinders, the registration correction is compensated.

The features disclosed above can be used not only in the regulation or Control of those cylinders are used that are in register with one The reference color printing cylinder must be coordinated. The the reference color Printing cylinders themselves can be regulated and / or controlled in the same way. In order to print in register, this is advantageous, for example, if there is one common share in the manipulated variables of the register controller of all of the reference color following inks there.

The regulation and / or control of the circumferential register described can advantageously also for regulating and possibly controlling the cutting register be used, i.e. the register controls of the cylinders can also be made with regard to the cutting register can be adapted in a controlled manner. The cutting register can be edited in the course of Disturbance feedforward control, preferably with but also without controlled adaptation, also taken into account will.

Figur 1

einen Druckturm für einen Vierfarbendruck,

Figur 2

einen ersten Antrieb für jede der Druckeinheiten des Druckturms nach Figur 1,

Figur 3

einen zweiten Antrieb für jede der Druckeinheiten des Druckturms nach Figur 1,

Figur 4

einen dritten Antrieb für jede der Druckeinheiten des Druckturms nach Figur 1,

Figur 5a

einen Antrieb für ein Satellitendruckwerk,

Figur 5b

einen Antrieb für ein Zehnzylinderdruckwerk,

Figur 6

eine Umfangsregisterkennlinie für eine Druckfarbe,

Figur 7

einen Regelkreis zur Lageregelung eines auf eine Bahn druckenden Zylinders des Druckturms nach Figur 1,

Figur 8

einen Registerregler für den Regelkreis nach Figur 7,

Figur 9

den Verlauf der Registerabweichung bei Verstellung der Winkellage eines auf die Bahn druckenden Zylinders der zweiten Druckeinheit des Druckturms nach Figur 1,

Figur 10

den Verlauf der Registerabweichung der in der dritten Druckeinheit des Druckturms nach Figur 1 aufgetragenen Druckfarbe infolge der Verstellung nach Figur 9,

Figur 11

den Verlauf der Registerabweichung der in der vierten Druckeinheit des Druckturrns nach Figur 1 aufgetragenen Druckfarbe infolge der Verstellung nach Figur 9,

Figur 12

den Verlauf der Registerabweichung entsprechend Figur 9 zusammen mit dem Verlauf der die Verstellung des zweiten Zylinders bewirkenden Stellgröße,

Figur 13

die Auswirkung der Verstellung nach Figur 12 auf den Passer der nachfolgend gedruckten Farbe, für den Fall, dass die Regelstrecke mit dem Zylinder der nachfolgend gedruckten Farbe von der Regelstrecke mit der zuvor gedruckten Farbe nicht entkoppelt ist,

Figur 14

die Auswirkung der Verstellung nach Figur 12 auf den Passer der nachfolgend gedruckten Farbe, für den Fall, dass die Regelstrecke mit dem Zylinder der nachfolgend gedruckten Farbe von der Regelstrecke mit der zuvor gedruckten Farbe entkoppelt ist,

Figur 15

einen Registerregler für vier Zylinder und

Figur 16

eine Sprungantwort eines Entkopplungsgliedes nach Figur 15.

Preferred exemplary embodiments of the invention are explained below with reference to figures. Show it:

Figure 1

a printing tower for four-color printing,

Figure 2

a first drive for each of the printing units of the printing tower according to Figure 1,

Figure 3

a second drive for each of the printing units of the printing tower of Figure 1,

Figure 4

a third drive for each of the printing units of the printing tower of Figure 1,

Figure 5a

a drive for a satellite printing unit,

Figure 5b

a drive for a ten-cylinder printing unit,

Figure 6

a circumferential register characteristic for an ink,

Figure 7

1 a control circuit for position control of a cylinder of the printing tower according to FIG. 1 printing on a web,

Figure 8

a register controller for the control circuit according to Figure 7,

Figure 9

the course of the register deviation when adjusting the angular position of a cylinder printing on the web of the second printing unit of the printing tower according to FIG. 1,

Figure 10

the course of the register deviation of the printing ink applied in the third printing unit of the printing tower according to FIG. 1 as a result of the adjustment according to FIG. 9,

Figure 11

the course of the register deviation of the printing ink applied in the fourth printing unit of the printing whirl according to FIG. 1 as a result of the adjustment according to FIG. 9,

Figure 12

9 shows the course of the register deviation according to FIG. 9 together with the course of the manipulated variable causing the adjustment of the second cylinder,

Figure 13

the effect of the adjustment according to FIG. 12 on the register of the subsequently printed color, in the event that the controlled system with the cylinder of the subsequently printed color is not decoupled from the controlled system with the previously printed color,

Figure 14

the effect of the adjustment according to FIG. 12 on the register of the subsequently printed color, in the event that the controlled system with the cylinder of the subsequently printed color is decoupled from the controlled system with the previously printed color,

Figure 15

a register regulator for four cylinders and

Figure 16

a step response of a decoupling element according to Figure 15.

Figure 1 shows a four-high tower of a web press for newspaper offset printing. The printing tower is formed by four printing units DE1 to DE4, which too two H-bridges are arranged one below the other in the tower. Each of the printing units comprises two blanket cylinders forming a printing nip for a continuous web B, starting with the first printing unit DE1 to the last printing unit DE4 of the printing tower are continuously designated 11 to 14 and 15 to 18. Each the blanket cylinder 11 to 18 is assigned a plate cylinder 21 to 28. The Plate cylinders 21 to 28 each subordinate ink and dampening units are the Not shown for clarity.

The web B is unwound from a paper roll of a reel changer and runs then over guide rolls and a pull roll 1 into the printing tower. The pull roller 1 is not coupled to the downstream pressure units DE1 to DE4 on the drive side. The web is printed in four colors on both sides of the printing tower. Since the invention is not is limited to the rubber / rubber production shown in Figure 1, but can also be used in satellite printing units, the Blanket cylinders 11 to 18 following their function of printing on the web Because of unspecifically referred to as a pressure cylinder. In the first printing unit DE1 the path through the first cylinders 11 and 15 on both sides with the preferred printed as the reference first color. The register accuracy when printing the second color by the second cylinders 12 and 16 in the second printing unit DE2 as well as the third and fourth color is always in relation to the first color measured and corrected.

Registration marks are printed on the web from each of the printing cylinders 11 to 18, by means of a pair arranged behind the fourth printing unit DE4 sensors 3, preferably a pair of CCD cameras 3, are recorded.

A further web tension roller 2 is arranged behind the fourth printing unit DE4 is also not coupled to the printing units on the drive side. Between two pull rollers 1 and 2 immediately at the entrance and at the exit before the first Printing unit DE1 or behind the fourth printing unit DE4, ie the first and the The last printing point for the colors to be printed one above the other is the web B curious; excited.

The arrangement of the sensor or sensors 3 comes from the speed of the color register control and, if necessary, control, especially in the case of transient ones Operations. In such phases, it is important to intervene in good time, so that the color register or registers do not run out of tolerance. Around the time between the occurrence of a fault and the rectification of the fault, i.e. the error runtime, too First, minimize the printing units DE1 to DE4 as close as possible lying together. In terms of minimizing errors, it would be optimal to arrange a sensor 3 immediately behind each printing point. However, it has proven to be sufficient and proven to be advantageous from a cost point of view, only one sensor 3 per web side, and this sensor 3 as close as possible behind the last Place the printing point that is to be registered with the reference color. The Printing point for printing the reference color, on the other hand, should be the one from sensor 3 most distant.

To increase the flexibility of the machines with regard to changing productions increase, it may also be preferred to use the reference color of the respective production to be able to select customized. An evaluation electronics at sensor 3 or the Register controller 30 is the location of the Print of the reference color communicated, so that the registration of the Printing cylinder can be made accordingly.

The register-based coordination of the printing cylinders printing on one side of the web B. 11 to 14 is carried out by means of register controllers 30. In the exemplary embodiment, the each one of the register regulators assigned to the pressure cylinders 11 to 14 physically in summarized in a single register controller 30. An input of the controller 30 are recorded by the sensor 3 assigned to the respective web side Register deviations fed. The register controller is via another input 30 connected to a bus of a higher-level controller. The parent In the exemplary embodiment, control comprises a control center 4, section computers 5 and Service interfaces accessible via modems 6. The setpoints for the drive control the motors 10 are given by means of the higher-level control. The Register control arrangement for those printing on the other side of the web B. Cylinder 15 to 18 is a mirror image of the register control arrangement for the cylinders 11 to 14.

The time between the detection of an error and the output of the corresponding one The manipulated variable should be as short as possible. A register controller 30 for an engine one the cylinders 11 to 18 are adjusted, inter alia, to the error running time. A controller parameterization can therefore also depend on the operation of the machine of error runtimes vary, particularly when the web speed changes or a change in the distance between the location of the fault and also change the sensor 3 with changing productions. Also the dynamics of the partial controlled system can be included in the parameterization, in particular the free web length between the previous printing point and the considered Pressure point of the partial controlled system.

Finally, the transfer of the manipulated variable of the register controller 30 should be as fast as possible and the actuator itself should match the dynamics of the register controller Can participate in 30 output manipulated variables.

Figures 2 to 4 show each other alternative drive concepts for each individually driven printing units DE1 to DE4.

In the drive for the printing units shown in Figure 2, the Pressure gap forming cylinder, for example 11 and 15, each via a gear 10.1, preferably a toothed belt, driven by a motor 10. The so directly driven cylinders 11 and 15 are mechanical with their subordinate ones Plate cylinders 21 and 25 coupled so that they have gears, not shown drift onto these downstream plate cylinders. Between the pressure gap forming cylinders 11 and 15 there is no positive coupling, so that a decoupling of the drive on the train can be spoken. The immediately driven cylinders 11 and 15 are relative to their angular position other cylinders printing on the same side of the web are regulated to deal with these to print further cylinders in register.

In the drive concept shown in FIG. 3, the pressure gap is used instead forming cylinders 11 and 15 whose downstream plate cylinders 21 and 25 each a gear, preferably in turn a toothed belt, directly driven, and the cylinders 11 and 15 are via gear trains, not shown, from the plate cylinders 21 and 25 starting with driven. Otherwise the two agree Drive concepts according to Figures 2 and 3 match.

Figure 4 shows a further drive concept in which both the two the pressure gap forming cylinders 11 and 15 and their respective downstream plate cylinders 21 and 25 are mechanically coupled together and by a common motor 10 are driven. The drive from the motor 10 is in turn a Gear, preferably a toothed belt, the pressure gap on one of the two forming cylinders 11 and 15, from which then again via a gear train on the with driven further cylinders, namely the counter cylinder and the plate cylinder, is aborted.

During the drive concepts shown in Figures 2 to 4 rubber / rubber production Figures 5a and 5b show that the concept of the individual driven cylinders that print on the web also in satellite printing units in can be used in the same way. A central steel cylinder 19 is shown in FIG Gear, preferably a toothed belt, driven by a motor 10. With this central cylinder 19 pressure gaps or pressure points forming cylinder 11 'to 14 'are each, preferably in turn, by a motor via a transmission Toothed belt, driven, and from these cylinders 11 'to 14' is positive the downstream plate cylinders 21 'to 24' driven off. With a dashed line Line is indicated in Figure 5a that the central cylinder 19 also mechanically one of the cylinders 11 'to 14' could be coupled, that is to say with a positive fit this cylinder could be communicating, so your own engine for this Central cylinder 19 would be omitted in this case. Even with the satellite printing unit 5a each print on the same side of a web Cylinders 11 'to 14' are regulated in their angular positions relative to one another in register. Also one Superposition of the regulations for the central cylinder 19 with each of the cylinders 11 up to 14 can be profitable in terms of minimizing deviations from ideal size registers are used. Figure 5b shows the corresponding on Example of a ten-cylinder printing unit with two central cylinders 19.1 and 19.2.

The color cylinders arranged downstream of the plate cylinders 21 to 24 or 25 to 28 as well as 21 'and 24' and dampening systems can use the plate cylinders to drive them together mechanically coupled, i.e. by positive locking. The ink and dampening systems can also be powered by your own motors. Are advantageous on the Units to be driven on the drive side, which have approximately the same moments of inertia have, so that with a few motor sizes, preferably a single motor size, the drive requirements of the printing press can be covered.

FIG. 6 shows a characteristic curve obtained by measurement and interpolation for the register deviation Y _{12 of} the second cylinder 12 from the first cylinder 11. The first cylinder 11 is the reference cylinder. The register deviation Y ₁₂ is plotted against the peripheral speed v _{2 of} the second cylinder 12. The characteristic of FIG. 6 is reproducible.

Such characteristic curves can be determined in particular for different machine types, different paper qualities and different machine configurations, ie for different path lengths between two adjacent printing points and stored in a machine's own database. On the basis of these data records stored in the database, the appropriate data record can be selected after appropriate selection of the machine type, the type of paper currently used and the machine configuration currently set. A compensating register correction is then determined on the basis of the relationship shown in FIG. 6 from the circumferential speed v ₂ currently in production.

A characteristic curve, like that of FIG. 6, is given for each pressure drop of the second cylinder 12 or 16 as well as to be coordinated accordingly for the other registers Cylinder determined. The characteristics are in the different pressure cases different, for example, because of different paper qualities that same web circumferential speed show different web tensions. In particular, differing pathways cause changes in production a changed path behavior. For the engine governors of those cylinders Printing units that follow the first printing unit DE1 serving as a reference the appropriate curve selected from the database. Depending on the current Cylinder peripheral speed becomes a correction quantity, i. H. the proportion of a disturbance variable to be switched on, based on the selected characteristic and the Command variable of the engine controller 8 switched on.

If necessary, a disturbance variable is also applied to cylinders 11 and 15 the first printing unit DE1. The activation of such a disturbance variable also with the first cylinders 11 and 15 make sense, in particular, for cutting register control.

If the reference cylinder can be freely selected to increase flexibility, characteristic curves Y _kl (v ₁ ) are measured and made available in a machine-specific database. In Y _kl , the index k denotes the reference cylinder and the index 1 the respective subsequent cylinder to be matched in register. In the exemplary embodiment with the first cylinder 11 as a reference cylinder, this means that k = 1 and 1 = 2, 3, 4.

In Figure 7 is a controller arrangement for those printing on the right side of the web Cylinder 11 to 14 and, as indicated, also for those printing on the left side of the web Cylinder 15 to 18 shown. In the following, however, it will only be the regulation described on the right side of the track. The following applies to the regulation to the left of the railway corresponding.

The registration marks printed on the web are picked up by the sensor 3 and evaluated in the measuring head of the sensor 3. From the output of the sensor 3, the determined register deviations Y _{1, 1 of} the cylinders 12, 13 and 14 are led to the reference cylinder 11 at an input of the register regulator 30. The register controller 30 is divided internally into a register controller for each of the cylinders 11 to 14. From these register deviations, each of the individual controllers of the register controller 30 forms a manipulated variable for its controlled system, the relevant cylinder, its engine 10 and engine controller 8, the path and the Includes sensors.

The angular positions of the cylinders 11 to 14 are regulated by a motor controller 8 each. For this purpose, an individual target angular position is formed for each of the cylinders 11 to 14. The angular position ϕ is represented by a length u [mm] developed from the cylinder circumference. The setpoint angle position is composed of the component u _{i, setpoint} , which is specified by the higher-level control 4, 5, 6, and a correction du _i . A comparison is now made between the target angular position and the actual angular position u _{i, actual} recorded by a sensor 7. The actual values are preferably recorded at the torque-free ends of the cylinders 11 to 14. The comparison result, the difference, is converted by the engine controller 8 into a manipulated variable for its engine 10.

The control for the second cylinder 12 is shown in more detail as an example in FIG. The same applies to the register control of the other cylinders. Input variables for the register controller 30 or the individual register controllers constituting this controller 30 (FIG. 15) are, on the one hand, the register _deviations Y _kl = (Y ₁₂ , Y ₁₃ , Y ₁₄ ) recorded and determined by the sensor 3. Y _{12 represents} the register deviation of the second cylinder 12 from the first cylinder 11. The same applies to the further register deviations. The measured peripheral speeds v ₁ to v ₄ (= v ₁₂₃₄ ) of the cylinders 11 to 14 are also fed to the register controller 30. It would also suffice to use the peripheral speed of only one of the cylinders 11 to 14 to be adjusted in register for the others, preferably that of the reference cylinder.

The register controller 30 is connected via a third input to the higher-level controller, which is simply identified by 4 in FIG. At the third input there are parameter _base values k _base = (k _{P base} , k _{l base} , k _{D base} , k _{f base} ) and, where appropriate, coefficients a _P , a _l , a _D for the second cylinder 12 three basic values are for the controller, the fourth for a filter. _Basic parameter values k _Basis are accordingly also supplied for the third cylinder 13 and the fourth cylinder 14 and, if appropriate, also for the first cylinder 11. The register controller 30 forms its manipulated variable du _{2, R} from these input variables, ie the register deviation Y ₁₂ , the peripheral speed v ₂ and the basic parameter values. This output variable or manipulated variable _is fed to the input of motor controller 8 together with its reference variable u _{2, intended} by controller 4 and actual angular position u _2, in the form of the difference u _2, Soll + du ₂ - u _{2, is} supplied. For example, a PID controller known from EP 0 644 048 can be used as the motor controller 8.

The register controller 30 of the exemplary embodiment is also designed as a controller with PID elements, each with controller parameters k _P , k _l and k _D. Each of these controller parameters is formed by the register controller 30 as a function of the respective basic parameter value and the peripheral speed of the cylinder, ie as a function of the individual basic parameter values and peripheral speeds per cylinder. It therefore applies individually to each of the cylinders 11 to 14:

In the exemplary embodiment, as will be described below, one coefficient each a per controller parameter k. Each of the controller parameters is thus as a function of the respective basic parameter value, a cylinder-specific or a representative speed that is the same for all cylinders, and if necessary the last-mentioned coefficient.

In the exemplary embodiment, the _basic parameter values k _{basis are determined} solely as a function of the dynamics of the partial controlled systems, ie only or at least mainly from the path paths to the preceding cylinder and to sensor 3. The controller parameters of the exemplary embodiment are proportional to the product of the basic parameter value and peripheral speed, ie the following applies:

The aforementioned relationships according to (1) and (2) between the controller parameters and the variables that determine them apply to each of the register-specific ones Cylinder with their own basic parameter values. When creating the weights the I and D components in an algebraic rhythm for a preferably discrete controller the sampling time T flowing into the weighting is preferably constant, at least in areas, i.e. within given speed ranges, kept constant.

The _basic parameter values k _basis and the possibly used coefficients a for the controller parameters are anticipated by the machine controller in the event of a production change and the associated pressure point reshaping. In the exemplary embodiment, the basic parameter values only take into account the length of the web to the printing cylinders preceding each in printing. A corresponding setting on the machine control station 4 is converted by the machine controller into the basic parameter values and passed on to the register controller 30. These basic parameter values then apply until the pressure setting is changed again. The cylinder peripheral speeds v ₁ to v ₄ are measured and continuously used in real time by the register controller 30 to form its output variable du _{i, R} as part of a suitable control algorithm, preferably a PID control. However, a circumferential speed measured for one of the cylinders 11 to 14 can also be used for all cylinders to be coordinated with one another in register.

The output variable du _{2, R of} the register controller 30 formed by controlled adaptation, the peripheral speed v _{2 is added} as a disturbance variable by a control element 40. The sum du ₂ formed therefrom is added to the reference control variable u _{2, target of} the machine control 4, and the difference between the reference variable formed in this way and the measured actual position value u _{2, actual} is the control deviation for the motor controller 8.

An output variable du _{2, S} as a correction variable is formed in the control element 40 as a function of the speed v _{2 of} the second cylinder 12, which is preferably measured. For this purpose, characteristic curves are stored in a memory of the control element 40 for the relationship between the register deviations and the cylinder speeds. The register deviation Y ₁₂ , which is dependent on the speed v _{2 of} the second cylinder 12 _, is used to form the correction value or the disturbance variable connection component du _{2, S} , as is shown, for example, in FIG. 6. The control element 40 uses this characteristic curve to calculate the correction variable du _{2, S used} to compensate for the register deviation Y ₁₂ , ie depending on the definition of Y ₁₂ and du _{2, S} , a scaling and / or a sign change takes place as the conversion. In the exemplary embodiment, only one characteristic curve is stored in the memory of the control element 40 for each of the register deviations Y ₁₂ to Y ₁₄ , in particular the characteristic curve of FIG. 6 for the second cylinder 12, ie in this case only the peripheral speeds of the cylinders are used as input variables for the control element 40 used. However, since the register deviations generally also depend on other influencing variables, in particular the free path length to the preceding cylinder and sensor 3, the ink and dampening solution guide and also on the paper quality, a representative, average curve is used when only one characteristic curve is used for the respective register deviation saved. In an advantageous development, however, sets of curves can also be stored in the memory of the control element 40 for each of the register deviations. In this case, the characteristic currently to be used is selected by the controller 4 via a line drawn with a dot-dash line in FIG. A single one of the speeds v ₁ to v ₄ , in particular that of the reference cylinder, can also be used as a representative speed instead of individual speeds for the formation of the correction variables du _{i, s} . Instead of permanently storing the characteristic curve or characteristic curves in a memory of the control element and selecting the relevant one for the respective pressure case, the characteristic curves could also be stored in a database of the machine control and entered into the control element memory at the start of production via the Y _KL bus.

The correction variable du _{2, S} can also be used alone in stationary and in non-stationary operation of the machine to compensate for systematic register errors or register deviations. This mode is indicated by an open switch at the output of the controller 30. The Aufschaltgröße you is ₂ in this case is identical to Störgrößenanteil du _{2, S} (= correction value) of the control member 40. However, the intrusion of this correction variable is also optional, Aufschaltgröße that you _two can also be identical to the manipulated variable du _{2, R} of the regulator Be 30. This mode is also symbolized by an open switch. Likewise, du _{i, R} and du _{i, S} can together form the override variable du _i , ie both symbolic switches are closed in this case.

The control member 40 can, as shown in Figure 8, independently in addition to that Motor controller 8 and the register controller 30 may be provided. However, it can also be advantageous divided into individual control elements for the individual cylinders 11 to 14 and be directly upstream of the engine controllers 8 in this division. A third possibility, namely the implementation of the control element 40 Individual control elements 41 to 44 in the register controller 30 are shown in FIG.

FIGS. 9 to 11 show the influence that a register adjustment made on the second cylinder 12 exerts on the registers of the following cylinders 13 and 14. FIG. 9 shows the deviation of the register of the second cylinder 12 from the first cylinder 11 over time in the case of a rectangular excitation du ₂ . At a predetermined first time t1, the register of the second cylinder 12 was adjusted by 1 mm and reset at a predetermined second time t2. The adjustment of the second cylinder 12 is only noticeable in the register of the subsequent third cylinder 13 at the aforementioned first and second point in time, that is to say the transition points in FIG. 9, by means of a first and a second projection below and above the line for zero deviation. The register of the fourth cylinder 14 according to FIG. 11 shows a similar behavior. The proportions du ₃ and du ₄ in the reference variables for their motor controller 8 are zero.

For another exemplary register adjustment, the change in the excitation du _{2 is} shown in FIG. 12 in addition to the course of the register deviation Y ₁₂ .

FIG. 13 shows the course of du ₃ and the course of the register deviation Y ₁₃ for the third cylinder 13. The register adjustment according to FIG. 12 for the second cylinder 12 also brings about an adjustment of the circumferential register in the subsequent cylinders 13 and 14, as already shown in the figures 10 and 11 is shown. As soon as a register deviation Y _{13 has been} determined by the sensor 3, the motor of the third cylinder 13 is readjusted to eliminate the register deviation Y ₁₃ . The portion du ₃ of the reference variable corresponding to the readjustment for the engine controller 8 of the third cylinder 13 is shown in FIG. In FIG. 13 it can be seen that this command variable is only changed by du ₃ with a certain time delay in relation to the register deviation Y ₁₃ that has occurred. The controlled systems for the two cylinders 12 and 13 are coupled. As FIG. 13 shows, the delayed change du ₃ not only causes the register deviation Y ₁₃ to arise undisturbed, it also causes the register deviation Y ₁₃ to overshoot in the other direction after Y _{13 has been} reduced. The overshoot occurs even at a time when the register deviation Y ₁₃ would run back against the desired zero deviation without the change du ₃ . The overshoot is caused by du _{3 in the} first place.

FIG. 14 shows the course of the register deviation Y _{13 of} the third cylinder 13 in the event that a decoupling for the control systems of the second cylinder 12 and the third cylinder 13 is undertaken or activated.

The favorable course of the register deviation Y _{13 of} the third cylinder 13 in relation to the first cylinder 11, which is favorable in FIG. 14, is achieved in that the reference variable of the motor regulator 8 for the third cylinder 13 adds up a certain proportion of the output of the register regulator for the second cylinder 12 becomes. The totalization compensates for the influences in the sense of a register-based coordination which result from the influence of the web tension by the register adjustment of a previous cylinder. The summation just described for the reference variable of the engine controller for the third cylinder 13 can be carried out alone or in combination with the disturbance variable connection already mentioned.

Figure 15 shows an embodiment of the register controller 30, the integration of the control element 40 in the controller 30 of FIG. 8 arises. There are also decoupling elements intended.

On a first bus v and a second bus k _base , which can also be combined to form a single bus, the circumferential speeds v ₁ to v _{4 of} the four cylinders 11 to 14 printing on the same web side and the Basic parameter values for these cylinders are supplied. The coefficients a, which may be specified with the _basic parameter values, are transmitted via the K _base bus or a separate bus.

The register controller 30 has a main controller for each of the cylinders 11 to 14. The respective main controllers are labeled 31 to 34. Each of these is a PID controller. Each of the main controllers 31 to 34 and the filters 1 to 4 is supplied with the individual set of parameter _basic values k _{Pi, base} , k _{li, base} , k _{Di, base} and k _{fi, base} for its cylinder; cylinder-specific coefficients a _Pi , a _li , a _{Di are also} fed to the main controllers. The register deviations Y ₁₂ to Y ₁₄ are fed to the main controllers 32 to 34 via an upstream filter, namely filter 2, filter 3 and filter 4. At the beginning of a production for this production, the basic parameter values are read once for the entire production into a memory of the main controllers 31 to 34. However, it is also possible for a plurality of sets of basic parameter values which are specific for production to be used, for example a first set for a first speed range and a second, possibly a third set for a second or even third speed range of the cylinders. In the exemplary embodiment, the basic parameter values only take into account the length of the free path in front of the respective cylinder and the length of the path from the cylinder to the sensor 3. If a sensor 3 is provided for each of the cylinders 11 to 14, the basic parameter values must match the respective path lengths up to do not consider such individual sensors 3. From the basic parameter values and the measured cylinder peripheral speed, each of the main controllers 31 to 34 forms its controller parameters k _P , k _l and k _D according to the relationships:

The values for the coefficients a _P , a _l , a _D reach the main controllers in the same way as the k _basic values. The a values are preferably also also always changed when the k _base values are changed.

Within the same production, the cylinder-specific coefficients a and the basic values k _{basis can} vary in discrete steps depending on the cylinder peripheral speed, preferably in only two or three steps over the entire speed range.

In an advantageous development, the coefficients k _{f of} the upstream filters, filters 1, 2, 3 and 4, can also be adapted in a controlled manner in accordance with such relations and equations (1) to (3).

The output variables du _{i, R of} the main controllers 31 to 34 are each subjected to the additive components du _{i, S} in the manner described for FIG. 8.

Furthermore, the output variables of decoupling elements EG ₃₄ , EG ₂₃₄ and EG _{1234 are also added} . In the exemplary embodiment with the first cylinder 11 as reference cylinder and the cylinders 12, 13 and 14 following in their numbering, the decoupling element EG _{34 is} sufficient for decoupling the main regulator 34 from the main regulator 33 and the further decoupling element EG ₂₃₄ for decoupling the main regulator 33 and 34 from the main regulator 32. The control elements 41 to 44 are also included in the decoupling.

FIG. 15 shows the case in which the first cylinder 11 prints the reference color. In this case, Y ₁₁ is by definition zero; likewise you _lR . In this case, the feedforward control acts only on the cutting register for the first cylinder 11. If the reference color is printed by one of the other cylinders 12, 13 or 14, the same applies accordingly to the cylinder then printing the reference color. If a common part occurs in the register deviations Y ₁₂ , Y ₁₃ and Y ₁₄ and if necessary this common register deviation part is compensated for in the first cylinder 11, the reference cylinder, or in the case of cutting register adjustments, the controlled systems of the cylinders 12, 13 and 14 are made by a corresponding decoupling element EG ₁₂₃₄ decoupled from the controlled system of the first cylinder 11 in the same way. If the reference cylinder can be freely selected, the cylinders 11 to 14 are preferably all decoupled from one another via decoupling elements.

As already described in connection with FIG. 8, the connection of the disturbance variable components du _{i, S is} optional. Likewise, the output variables du _{i, R of} the main controllers 31 to 34 can be dispensed with at least temporarily if one can be satisfied with the compensation of the purely systematic errors or at least some of the systematic errors. Likewise, the formation of a decoupling in terms of control technology by means of decoupling elements EG ₃₄ , EG ₂₃₄ and EG _{1234 is} optional.

FIG. 16 shows a step response or transfer function for the decoupling elements EG ₂₃ , EG ₂₃₄ and EG ₁₂₃₄ qualitatively as a function of time. The transfer function, which applies to all decoupling elements in this qualitative representation, drops from a positive initial value over time to almost zero. Since the control according to the invention is preferably a discrete control, the course of the transfer function decreases in a step-like manner. The output variables of the coupling elements are thus formed in such a way that the following cylinders deflect in such a way that their registers are changed as little as possible when a register has been adjusted on a preceding cylinder. The decoupling of the controlled systems according to the invention in the register controller 30 also contributes to the registration of cylinders printing on one side of the web with one another, that is to say without the controlled adaptation of the controller parameters and also without the interference variable, that is to say also brings them alone or in optional combination with one the other two solutions have advantages in register accuracy.

Claims (24)

Method for register-based tuning of cylinders printing on a web of a web press, in which a) a first cylinder (11) printing on one side of the web is driven by a first motor (10) and a second cylinder (12) printing on the same side of the web is driven by a second motor (10) and b) the angular position of the second cylinder (12) is adjusted in register with the first cylinder (11) by a controller (30; 32), characterized in that c) when a production condition changes, at least one controller parameter (k _P , k _D , k _l , k _f ) of the controller (30; 32) is changed and the controller setting is thereby adapted to the production condition. Method according to claim 1, characterized in that in the formation of the at least one controller parameter (k _P , k _D , k _l , k _f ) a _basic parameter value specific for production (k _{P basis} , k _{D basis} , k _{l basis} , k _{f Base} ). A method according to claim 2, characterized in that the basic parameter value is changed at most twice during this production and preferably is constant during this production. Method according to Claim 2 or 3, characterized in that the _basic parameter value (k _{P basis} , k _{D basis} , k _{l basis} , k _{f basis} ) is at least also determined by a change in a web length as a result of a pressure point remodeling. Method according to one of the preceding claims, characterized in that the at least one controller parameter (k _P , k _D , k _l , k _f ), preferably in adaptation to the peripheral speed of one of the cylinders (11, 12) which print on the same web side of the cylinder (12) to be tuned in each case is changed. Method according to the preceding claim, characterized in that the peripheral speed is linear when the at least one controller parameter (k _P , k _D , k _l , k _f ) changes. A method according to claim 5 or 6, characterized in that the measured Peripheral speed is used. Method according to one of claims 2 to 7, characterized in that to form the at least one changed controller parameter (k _P , k _D , k _l , k _f ) the _basic parameter value (k _{P basis} , k _{D basis} , k _{l basis} , k _{f Base} ) is multiplied by a quantity which depends on the peripheral speed of one of the cylinders (11, 12) which print on the same web side, preferably of the cylinder (12) to be matched. Method according to one of the preceding claims, characterized in that all controller parameters (k _P , k _D , k _l , k _f ) of the controller (30; 32), possibly also of an upstream filter (filter 2), are changed in an adapted manner. Method according to one of the preceding claims, characterized in that an output variable (du _{2, R} ) of the controller (30; 32) for the second cylinder (12) is subjected to an interference variable (v ₂ ) to compensate for a phase characteristic of a machine operation and therefore predictable, reproducible register deviation (Y ₁₂ ) of the second cylinder (12) compared to the first cylinder (11). Method according to one of the preceding claims, characterized in that a motor controller (8) for the second cylinder (12), for a reference variable (u _{2, target} ) for the synchronous operation of the first and the second cylinder (11, 12) is a disturbance variable (v ₂ ) is switched on to compensate for a reproducible register deviation (Y ₁₂ ) of the second cylinder (12) typical of the respective phase and therefore predictable, from the first cylinder (11), the circumferential register of the second cylinder (12) being determined by means of the reference variable ( u _{2, target} ) and the disturbance variable (v ₂ ) can only be controlled. Method according to one of the preceding claims, characterized in that values for register deviations (Y ₁₂ ) of the second cylinder (12) determined from a measurement or simulation of an acceleration or deceleration phase at different peripheral speeds (v ₂ ) of the second cylinder (12) in a digital memory of a control element (40) or a higher-level control (4, 5, 6) are stored. Method according to the preceding claim, characterized in that speed-dependent register deviations also for alternative transport routes the web are stored in the memory. Method according to at least one of the two preceding claims, characterized in that the speed-dependent register deviations also for different web materials and possibly also for specified ones different degrees of color coverage are stored in the memory. Method according to one of the preceding claims, characterized in that a third cylinder (13) printing on the same side of the web is decoupled from a correction of a register deviation (Y ₁₂ ) of the second cylinder (12) made for the second cylinder (12), by feeding the quantity (du _{2, R} ) for the second cylinder (12) which causes this correction of the register deviation (Y ₁₂ ) of the second cylinder (12) to a decoupling element EG ₂₃₄ and its output signal (E ₂₃₄ ) to a manipulated variable (du _{3, R} ) for correcting register deviations (Y ₁₃ ) of the third cylinder (13). Device for register-based tuning of cylinders printing on a web of a web press, with a) a first cylinder (11) printing on one side of the web, which is driven by a first motor (10), and a second cylinder (12) printing on the same side of the web, driven by a second motor (10) will, and b) a controller (30; 32) for register-based tuning of the second cylinder (12) to the first cylinder (11), characterized in that c) at least one controller parameter (k _P , k _D , k _l , k _f ) of the controller (30; 32) can be changed during operation of the machine. Device according to the preceding claim, characterized in that the controller (30; 32) has a signal processor and a memory in which _basic parameter values (k _{P basis} , k _{D basis} , k _{l basis} ) are assigned by a higher-level controller (4, 5, 6) _' k _{f basis} ) to form the at least one changeable controller parameter (kp, k _D , k _l , k _f ). Apparatus according to claim 16 or 17, characterized in that the Regulator (30; 32) the peripheral speed of one of the same side of the Web printing cylinder (11, 12), preferably the cylinder to be tuned (12) is supplied. Device according to claim 17 and 18, characterized in that a multiplier of the controller (30; 32) to form the at least one changeable controller parameter (k _P , k _D , k _l , k _f ) the peripheral speed with the _basic parameter value (k _{P basis} , k _{D base} , k _{l base} , k _{f base} ) multiplied. Device according to one of claims 16 to 19, characterized in that a control element (40; 42) is provided which, from an interference variable (v), a correction variable (du _{2, S} ) for compensating for a register deviation (v) typical of the interference variable (v) Y ₁₂ ) of the second cylinder (12) forms from the first cylinder (11), which is connected to a motor controller (8) of the second cylinder (12). Device according to the preceding claim, characterized in that the control element (40; 42) has a memory in which at least one characteristic curve for the course of the register deviation (Y ₁₂ ) of the second cylinder (12) from the first, which is dependent on the disturbance variable (v) Cylinder (11) is stored. Device according to at least one of the two preceding claims, characterized in that the control element (40; 42) has the at least one disturbance variable (v) via a first input and the at least one characteristic curve (Y ₁₂ (v )) or a selection signal for selecting this characteristic curve from characteristic curves stored in a memory of the control element (40; 42) is supplied. Device according to one of claims 20 to 22, characterized in that the control element (40; 42) is part of the register regulator (30; 32). Device according to one of claims 20 to 22, characterized in that the control element (40; 42) independently or part of a higher-level machine control (4, 5, 6).

Images