EP1505023A2 - Method and device for controlling the web tension and the cutting register of a rotary printer - Google Patents

Abstract

For control purposes, image information or measurement marks are registered by a sensor (5, 6) from the printed web. The web tension (F) is measured by a further sensor (8). From the image information, differences in location relative to the desired position in terms of displacement and time are determined to obtain the partial and total cutting registration errors. Their actual values are fed to a controller (2) which provides independent control over the error and web tension. An independent claim is included for corresponding equipment.

Description

The invention relates to a method and a device for regulating the Web tension and cut register of a web-fed rotary press.

In web-fed rotary printing presses, it is known as an actuator for the Cut register control a positioning roller which can be moved in linear guides used to change the Papierweglänge between two train units and to correct the register error. Such register rollers are shown for example in DE 85 01 065 U1. The adjustment takes place in Generally by means of an electric stepper motor. Such devices are with a relatively large mechanical and electrical effort afflicted.

It is an object of the invention to provide an accurate method of controlling the Cutting register and the web traction to create.

The object is achieved with the features of the independent claims.

It is significant that it is now possible to edit the cut register (total cut register error and / or partial cut register error) and the web tensile force in a same or in different sections of the printing press decoupled from each other at the same time and in a regulatory sense where both sizes are specified independently.

In the method according to the invention for controlling the cut register, the Running time of the railway image points adjusted at a constant path, while According to the prior art, a track length change at constant Path speed is made. In the method according to the invention to control the web tension, the lead (speed) is not one pressure-changing nip changed, with both interventions by Decoupling measures to ensure a stable overall This was previously not possible in the prior art.

It is significant that for controlling the cut register, certain image information or measurement marks of the printed web are detected by means of at least one sensor and the web tension by means of at least one further sensor and fed to a control device. The partial cut register error Y ^* _{1 i to} be controlled are at or before a terminal point i and the web tension F _{k -1, k} or F _{i -1, i} to be controlled at or before another terminal point k or the same terminal point i, where the nip points are non-printing and in each case in front of the knife cylinder (nip 4), measured and these control variables - the web tension F _{k- 1 , k} or F _{i -1, i} and the part-cut register error Y ^* _{1 i} - by suitable manipulated variables ν _{i -1, i} , ν _i , ν _{k -1, k} , ν _k and associated controllers in the control-technical sense decoupled from each other according to corresponding set values Y ^* _{1 iw} , F _{k- 1 , k, w} , F _{i -1, i , w are} set so that the web tensile force takes its setpoint, which is within a prescribed range, and the partial cut register error is corrected to the target value, for example the value zero.

Preference is given to determining the controlled variables of sensors, however, models may also partially or completely replace these sensors, i. The quantities are equivalently determined by means of mathematical or estimated empirical models

The manipulated variable for the cutting register is the lead of a non-printing nip and the manipulated variable for the web tension is the lead or position of the printing units, both schemes are implemented by appropriate control circuits that the normal drive controls from current, speed and / or angle control be subordinated. Alternatively, the manipulated variable for the cutting register is the speed ν _{k of} a clamping point k and the manipulated variable for the web tensile force the velocity ν _{i of} a clamping point i, wherein when the speed ν _{i of} this clamping point changes, the force F _{i, i + 1} in the following path section is not self-compensating may be. This is the case when moisture and / or heat is introduced into the web in the leading web sections. In particular, the lead of a cooling unit in a web-fed printing press can be used for this purpose. As a manipulated variable for the web tension and the force exerted by the dancer roll force can be selected on the web, which is determined from the pressure of the associated pneumatic cylinder, fed to a web tension and compared with the force setpoint, the output of the controller either directly the manipulated variable for the Pneumatic cylinder or the setpoint F _{01 w} , if a subordinate control loop for the input web tension F _{01 is} present. By this force adjustment is always ensured that the quickly occurred as a result of the regulation of a disturbance force change register error correction against this compensation is reduced relatively slowly.

It is significant that only all before the register error controlling terminal point, such as the turning unit, terminal points decoupling additional lead desired values received (backward decoupling) and that this decoupling for stable operation is mandatory and / or that also all after the registry error controlling nip , For example, the turning unit, lying terminal points decoupling leading additional setpoints received.

It is important that for partial decoupling in the reverse direction, the specification of the decoupling Voreilungs additional setpoint for the nip 2 in the form of an additional speed setpoint is performed and for the nip 1 in the form of a corresponding additional tensile setpoint at the input of the draft regulator via a correspondingly modified transfer function of the closed Traction control loop or the specification of the decoupling Voreilungs additional setpoint for the terminal point 1 in the form of a corresponding additional speed setpoint via balancing filter is performed. In addition, for decoupling in the forward direction via a transfer function F _x precontrol of the nip 3 by means of a corresponding register additional setpoint at the input of the register controller by means of another transfer function or via a balancing filter to the lower speed control loop of this register control loop.

It should be emphasized that the assignment of controlled variables and manipulated variables including all necessary for this constellation Decoupling and pilot control measures can be reversed.

The advantage is that the cut register error immediately before the knife cylinder can be measured and controlled by a register controller, the register controller the nip 3 is superimposed.

The solution according to the invention requires no additional mechanical Web guiding element. To cut register correction are existing, not pressure train units used, such as. B. the cooling unit, pull rollers in Falzaufbau, the funnel roller or more in the path between the last Printing unit and knife cylinder lying train units, preferably by means of Variable speed single drives are driven.

The parameters entering the cutting register control path are broad regardless of the characteristics of the rotary printing machine. Continue lets The accuracy of the cut register increase significantly with the new method.

The invention also relates to a device for carrying out the method for controlling the cutting register, the clamping points 1 to 4 are driven independently with drive motors with associated current, speed and optionally angle control and at the cut register and / or associated further register deviations Y * / 13, Y * / 1 i , Y * / ik on or in front of a knife cylinder and / or on or in front of one or more of these knife cylinder (nip 4) upstream clamping points i, k, 1 to 3 on a specific image information or measurement marks of the printed Track can be detected by at least one sensor and the web tension can be detected by at least one other sensor and these determined by the sensors data to influence the cutting register error Y ₁₄ a control and / or control device for changing angular positions or circumferential velocities ν ₁ to ν ₃ , ν _i , ν _{k of} the respective terminal point K _i , K _k , K ₁ to K _{3 can be} fed.

Further features and advantages emerge from the dependent claims in Connection with the description.

Fig. 1a:

Klemmstellen-Schema einer Rotationsdruckmaschine mit geregelten Antrieben,

Fig. 1 b:

Mechanisches System mit geregelten Antrieben,

Fig. 2:

Anordnung zum Regeln des Schnittregisters und der Bahnzugkraft,

Fig. 3:

vollständige Entkopplung der Regelgrößen auf mechanischer Ebene,

Fig. 4:

Teilentkopplung der Regelgrößen auf elektronischer Ebene mittels Zusatzsollwertes für die Bahnzugkraft (Fall a),

Fig. 5:

Teilentkopplung der Regelgrößen auf elektronischer Ebene mittels Symmetrierfiltern (Fall b),

Fig. 6:

vollständige Entkopplung der Regelgrößen auf elektronischer Ebene mit Hilfe von Zusatz-Sollwerten für Bahnzugkraft und Registerfehler (Fall a),

Fig. 7:

vollständige Entkopplung der Regelgrößen auf elektronischer Ebene mit Hilfe von Symmetrierfiltern (Fall b),

Fig. 8:

vollständige Entkopplung der Regelgrößen auf mechanischer Ebene,

Fig. 9:

Regelung des Schnittregisterfehlers mit unterlagerten, vollständig entkoppelten Regelkreisen (nach Fall a),

Fig. 10:

Anordnung zum Regeln des Schnittregisters mittels der Voreilung einer Klemmstelle und der Bahnzugkraft mittels der Voreilung der Kühleinheit,

Fig. 11:

vollständige Entkopplung der Regelgrößen auf mechanischer Ebene nach Fig. 10 und

Fig. 12:

vollständige Entkopplung der Regelgrößen auf elektronischer Ebene nach Fig. 11.

The invention will be explained in more detail below with reference to some embodiments. In the drawings shows schematically:

Fig. 1a:

Clamping diagram of a rotary printing press with controlled drives,

Fig. 1b:

Mechanical system with controlled drives,

Fig. 2:

Arrangement for controlling the cut register and the web tension,

3:

complete decoupling of the controlled variables on a mechanical level,

4:

Partial decoupling of the controlled variables on the electronic level by means of additional setpoint for the web tension (case a),

Fig. 5:

Partial decoupling of the controlled variables on the electronic level by means of balancing filters (case b),

Fig. 6:

complete decoupling of the controlled variables on the electronic level with the aid of additional set values for web tension and register errors (case a),

Fig. 7:

complete decoupling of the controlled variables on the electronic level with the aid of balancing filters (case b),

Fig. 8:

complete decoupling of the controlled variables on a mechanical level,

Fig. 9:

Control of the cutting register error with subordinate, completely decoupled control circuits (according to case a),

Fig. 10:

Arrangement for controlling the cut register by means of the advance of a nip and the web tension by means of the advance of the cooling unit,

Fig. 11:

complete decoupling of the controlled variables on a mechanical level according to FIGS. 10 and

Fig. 12:

complete decoupling of the controlled variables on the electronic level according to FIG. 11.

The following functional description is made on a four-roller system according to Fig. 1 a. It should be noted that in the real printing press in place of a nip 1 ( K ₁ ) of the four-roll system as many printing units, ie, for example, four printing units of a web offset commercial printing press or newspaper printing press or other type of rotary printing presses can occur. The principle of register and web tension control described below by the example of an illustration printing machine by two decoupled control loops is to be transferred to all rotary printing machines mutatis mutandis.

Regulation of register error at a non-printing nip the knife cylinder 1. Function explanation on the four-roll system

The four-roller system of Fig. 1a is a simplified form of a rotary printing machine, in particular a web offset printing machine. In one after the unwinding device, nip 0 ( K ₀ ), following nip 1 ( K ₁ ) all printing units are summarized. Between terminal point 0 ( K ₀ ) and 1 ( K ₁ ) is a dancer roller or a tension control loop for specifying the web tension F ₀₁ as an abbreviated representation of the device for adjusting the web tension on the unwinding ( K ₀ ) and in the feed train. Clamping point 2 ( K ₂ ) is in the case of an illustration printing press for the cooling unit, in between is optionally a dryer T, nip 3 ( K ₃ ) stands for the turning unit and nip 4 ( K ₄ ) for the folding unit with the cutting-determining knife cylinder. The magnitudes ν _i are the peripheral velocities of the clamping points K _i , which are approximated by the behavior of wound Coulomb friction rollers. In rotary printing presses, the term "overfeed" is used instead of the term "speed". The lead W _{i , i -1 of} a clamping point i ( K _i ) with respect to a nip i-1 ( K _{i -1} ) is given by the expression W i . i - i = ν i - ν i -1 ν i -1

In the following text, "speed" and "lead" are used interchangeably. The web force in a section i-1, i is referred to as F _{i -1, i} . In z _T , the changes of the modulus of elasticity and the section of the incoming web are summarized. Register error Y ₁₄ on the knife cylinder is referred to as overall cut register error or short as cut register error. A previously accumulated register error Y ^* _{1 i} , measured at a non-printing clamping point i, is called a partial cut register error, in short a partial register error.

The system 1 of FIG. 1 a is understood as a mechanical controlled system (block 1 a in FIG. 1 b) with associated actuators (controlled drives in block 1 b in FIG. 1 b). The two controlled variables are the partial cut register error Y * / 13 as a substitute quantity for the total cut register error Y ₁₄ and the web tensile force F ₂₃ . Manipulated variables are the lead of the clamping point 3 ( K ₃ ) and the lead or position of the clamping point 1. By appropriate control circuits, these variables should be specified independently of one another in accordance with set target values. The partial register error Y * / 13 is the deviation of a fixed image reference point, eg the image edge, at the nip 3 ( K ₃ ) from the position of this point at the nip 1 ( K ₁ ), relative to its correct position. The cutting register error Y ₁₄ is the error of the cutting edge at the clamping point 4 ( K ₄ ) at the time of cutting compared to their position at the nip 1 ( K ₁ ), based on their correct position.

The actuators form the controlled drive motors M ₁ to M ₄ . The input variables x _iw shown in FIGS. 1 a and 1 b represent the angular velocity (rotational speed) or angle desired values of the controlled drives M ₁ to M ₄ .

The system ₍₁ K) supplied to transient or stationary mass flow through the input of the clamping point 1, measured in kgs ^{- 1} is determined by the circumferential speed of the clamping point ν _1, 1 (K ₁₎ and the elongation ε ₀₁ determined. In the case of Hooke's material, the force F _{01 of} the strain ε _{01 is} proportional. The force F ₀₁ is set by the contact force of a dancer or pendulum roller to the continuous web or by a tension control loop - the circumferential speed of the nip 0 (directly or indirectly via a further device for setting the web tension - according to the position setpoint or force setpoint Unwinding) control. Only the peripheral speed of the unwinding device is able to stationarily change the mass flow introduced into the system. Hereinafter, it is assumed that changes of F ₀₁ or v ₁ as a result of the change in the peripheral speed of the unwinding device caused thereby change the transient as well as stationary mass flow in the following track sections. The peripheral speeds of the other terminal points can - assuming Hooke'sches material - not change the mass flow stationary. The peripheral speeds are referred to below as speeds.

2. Register control loop

The partial register error Y * / 13, as shown in FIG. 2, with the register controller 3.1 using the speed ν _{3 of} the nip 3 ( K ₃ ) - for example, a turning unit - to the predetermined target value Y * / 13 w , for example Y * / 13 w = 0, regulated. This closed-loop control circuit is subordinated to the speed control circuit 3.2 of the drive motor M3 assigned to the clamping point 3 ( K ₃ ). The very small equivalent time constant of the current loop underlying the speed control loop is negligible.

3. Traction control loop

After the register control via the advance of the clamping point 3 ( K ₃ ) is connected to a change in the web tension F ₂₃ , it can not be ruled out that large disturbances cause too small or too large web tension, which can lead to web breakage. The web tension F ₂₃ must therefore be limited. For this purpose, it is measured by means of a tensile force sensor 8, for example as a measuring roller, measured, fed to the comparison point of a draft regulator 1.1 and compared with the desired value F _{23 w} (see FIG. 2). The tension regulator 1.1 ensures compliance with the desired web tension F ₂₃ and at the same time allows their paper-type-dependent specification by the machine operator, who no longer has to intervene in the overfeed adjustment of the clamping point 3 ( K ₃ ). The tension controller 1.1 specifies the desired angle value α _{1 w} for the virtual guide shaft, ie the common setpoint value for the angle control loops of all pressure units and of the knife cylinder ( K ₄ ). Each angle control loop consists of an angle controller, the lower speed control loop including current loop (summarized in block 1.2).

4. Couplings between the controlled variables

The two controlled variables, namely the partial register error Y * / 13 and the tensile force F ₂₃ , are dependent on one another by the structure of the controlled system, ie coupled to one another. For example, if a setpoint change F _{23 w} made, the engagement of the draft regulator 1.1 is connected to a change in position of the printing units and causes a partial register error Y * / 13. The register control circuit (controller 3.1) now attempts to return this error Y * / 13 to the desired value Y * / 13, w , for example value 0, by a speed change ν ₃ , whereby the force F _{23 is} changed, thus the traction control circuit again etc. This can make the entire system unstable (see Fig. 2).

5. Principle of decoupling

The principle of decoupling is explained with reference to FIG. Without any decoupling measure, the partial register error Y * / 13 as well as the tensile force F ₂₃ depend on both manipulated variables, namely the speed changes ν ₁ and ν ₃ . The goal is to make Y * / 13 dependent solely on ν ₃ and F ₂₃ solely on ν ₁ .

5.1 decoupling method I (partial decoupling)

The first measure is to add the velocity ν ₃ to ν ₂ , that is, to communicate any movement of the nip 3 ( K ₃ ) to the nip 2 ( K ₂ ). This ensures that the correction of Y * / 13 with the help of ν ₃ no longer leads to a change of F ₂₃ , ie Y * / 13 no longer depends on F ₂₃ . But ν ₃ now also affects F ₁₂ . The second measure is therefore to add the velocity ν ₃ also to ν ₁ . As a result, the reaction from ν ₃ to F _{12 is} prevented. The clamping points 1 ( K ₁ ) and 2 ( K ₂ ) thus perform the same movement as the nip 3 ( K ₃ ). Thus F _{23 is} only affected by ν ₁ . The method already works stably with this partial decoupling.

5.2 decoupling method II (complete decoupling)

The partial register error Y * / 13 is still dependent on ν ₁ in the decoupling method I except from ν ₃ , its desired control variable. This dependence is canceled out by virtue of ν _{1 being passed} over the computable transfer function F _x and its output signal x being subtracted from ν ₃ . This precontrol is also carried out at ν ₄ and can optionally be done at ν ₂ (shown in phantom in Fig. 3). Now Y * / 13 depends solely on ν ₃ . Thus, the above-formulated rule target is reached. This method also works stably in the form described.

6. Realization of the decoupling

The four signal additions and subtractions described in FIG mechanical side of the plant. You have to be in the real one Plant within the regulations, ie on an electronic level, realized because they can not be introduced into mechanics.

6.1 decoupling method I

The addition of ν ₃ with ν ₂ takes place in the form of an angular velocity additional setpoint at the input of the speed control circuit 2.2, as FIG. 4 shows. The addition of ν ₃ to ν ₁ is realized in a case a) in the form of an additional setpoint at the input of the tensioning force regulator 1.1. For this purpose, the transfer function 1.3 of the reciprocal closed traction control loop is necessary. However, the addition can also be added in a case b) to the setpoint ω _{1 w} , as shown in FIG. 5. In this case, two balancing filters 1.4 and 1.5, cf. [Bra 96], provide that prevent the angle controller 1.6 and the draft regulator 1.1 respond to this pilot signal in a compensating manner. The pilot signal is not interpreted as a fault due to this measure.

6.2 Decoupling II

The output signal x of the transfer function F _x (block 1.7 in FIG. 6) is realized in a case a) as an additional setpoint value at the input of the register controller 3.1. For this, the transfer function 3.3 is necessary. The output signal x of the transfer function F _x is also subtracted via the adaptation block 4.1 from the angle setpoint α _4w . In a case b) of Fig. 7, the connection is made at the inputs of blocks 3.2 and 4.2. In this case, the balancing filters 3.4 and 4.3 are necessary.

7. Swapping the manipulated variables

If, in the above-explained regulation, the tensile force F _{23 was} regulated by the advance or speed v _{1 of} the nip 1 ( K ₁ ) and the partial register error Y ^* ₁₃ by the speed v _{3 of} the nip 3 ( K ₃ ), this can be done The tensile force F ₂₃ is regulated by the speed ν _{3 of} the clamping point 3 ( K ₃ ) and the register error by the lead or the angle of terminal point 1 ( K ₁ ). With partial decoupling, the transfer functions F _{x 1} and F _{x 2} can be calculated (compare Fig. 8). The result for the transfer function F _{x 1 is} an integral term 1.8 and for the transfer function F _{x 2} a DT1 element (first-order differentiating delay element) 3.5. For the commissioning makes an open integrator 1.8 difficulties, because the Integrationszeitkönstänte öft is due to the not sufficiently accurate track data only approximately calculable and the regulations are unstable. Therefore, the integrator 1.8 is replaced by a PT1 element (proportional-delay element of the first order): 1 T l s ≈ 1 1+ T l s

In this equation, _{T1 is} the integration time constant. The DT1 element in the transfer function F _{x 2} may be unfavorable due to harmonics in the measurement signals. Therefore, this control variant will only be of value in special cases. The forward decoupling is done by means of the block 1.9 similar to that in Fig. 3, thus resulting in a complete decoupling.

The described two-size controlled system can alternatively also after the Method of so-called. Complete series decoupling [Föl 88] are decoupled. Also here are two decoupling methods, as shown above, possible, and the decoupling results in a similar way.

8. Variants

As a manipulated variable for the web tension in a web section both the nip 1 (pressure units) and the web tension F _{01 come} into question, both because of their ability to change the introduced into the system transient and steady state mass flow that they directly or via further upstream Web tension adjustment devices change the peripheral speed of the unwinder.

In the case of the force F ₀₁ , the contact pressure of the dancer or pendulum roller is selected, for example, as a manipulated variable for the web tension F _{i -1, i} in the desired section i-1, i. In this case, the contact pressure 2 F _{01 of} the dancer roller is adjusted, for example via the pressure in the - not shown here - associated pneumatic cylinder via a corresponding pressure control loop. The dancer or pendulum roller system is to be equipped with the necessary data exchange with communication interfaces.

In the case of nip 1 (printing units), the speed ν _{1 of} the printing units is changed, this change also being communicated to the nominal position value of the knife cylinder ( K ₄ ) and possibly further nip points.

9. Self-compensation of a force

If the speed of one of the adjoining terminal points i or i, i + 1 ( K _i or K _{i, i + 1} ) is selected for the regulation of a force F _{i, i +1} , the property of the so-called self-compensation of the force F _{i, i +1} to note. In the case of a change of ν _{i +1} , the force F _{i, i + 1 changes} permanently, ie is completely controllable by ν _{i +1} . In the case of a change of ν _i, however, the force F _{i , i +1} changes only temporarily, ie not permanently, in the case of purely elastic web material (Hooke's material). Therefore, the force F _{i, i +1} is not fully controllable by ν _i . However, in order to be able to use ν _i as a manipulated variable, such a property of self-compensation must not be present. When ink and / or moisture is introduced during the printing process and / or when heat is applied, for example by means of a dryer in one of the sections before the nip i ( K _i ), the self-compensation characteristic is lost, and also F _{i , i + 1} changes permanently. In this case, ν _{i can also be used} as a manipulated variable in a traction control loop.

If the nip 2 ( K ₂ ), for example in the case of a commercial printing press, a dryer T upstream, so the speed v ₂ as a control variable for the force F _{i -1, i} in a traction control circuit (controller 2.1) can be used, said this Drive control 2.2 is superimposed. The Zügkräftregelkreis then works together, for example, with a register control loop (controller i.3) for Y ^* _{1 i} in decoupled form. Alternatively, for example, the force F _{23 could be} regulated.

By choosing a speed ν _i as the manipulated variable for controlling the web tension F _{i -1, i} , this force is permanently changed, all following web tension forces only temporarily, if F _{i , i +1 is} self-compensating. By choosing a speed v _{i -1} as the manipulated variable for controlling the web tension F _{i -1, i} , these and all following forces are permanently changed if F _{i -1, i} , as described above, is not self-compensating.

It should be noted that it would be possible to permanently change the force F _{i -1, i} by changing the force F _{i -2, i -1} and carrying ν _i at the speed v _{i -1} , so that ν _i = ν _{i -1} would be. Then, however, ν _{i is} no longer available as an independent manipulated variable for Y * / 1 i . However, the availability of two independent control variables is decisive for the decoupled specification of the two controlled variables, ie F _{i -1, i} and Y * / 1 i .

As a manipulated variable for the web tension force instead of the nip 1 (pressure units) also another terminal point can be selected.

A first possibility is to choose the contact force of the dancer roller as a manipulated variable for the web tension in the desired section, for example, the web tension F ₂₃ in the desired section 2-3. The contact pressure force 2 F ₀₁ (see Fig. 1a) of the - not shown - dancer roller is readjusted, for example via the pressure in the associated pneumatic cylinder via a corresponding pressure control loop. The dancer roller system is to be equipped with the necessary data exchange with communication interfaces. In place of the dancer roll can also occur a web tension control loop.

A second possibility is to use the speed of a nip, which must meet certain conditions, as explained below. When changing the velocity ν _{i of} a clamping point i ( K _i ), which lies between two terminal points K _{i -1} and K _{i +1} , whose velocities ν _{i -1} and ν _{i +1 are} constant, the force F _{i changes - 1, i} remaining, however, the force F _{i , i +1} only temporarily, ie not permanent. This property is called self-compensation of the force F _{i , i +1} and is in purely elastic web material. Under these conditions, the force F _{i , i +1 is} not fully controllable. When ink and / or moisture is introduced during the printing process and / or when heat is applied, for example by means of a dryer located in front of the nip ( _i ), the property of self-compensation is lost, and also F _{i , i + 1} changes permanently , The speed ν _i , the clamping point i ( K _i ) can serve under this condition as a manipulated variable for setting a web tension. If, for example, according to FIG. 1 a, the clamping point 2 ( K ₂ ) precedes a dryer in the case of an illustration printing press, then F ₂₃ can be regulated by a traction control loop with the aid of ν ₂ and then, as described above, operate with the register control loop for Y * / 13 in decoupled form together.

Regulation of register error on the knife cylinder

The combined cut register web tension control of a web-fed rotary press machine as described above, for example, as shown in Fig. 6, is capable of, on the one hand, the partial register error Y * / 13 according to the predetermined target value Y * / 13 w , for example Y * / 13 w = 0, and decouples the web tensile force F ₂₃ according to the setpoint F _{23 w} dynamic fast control. All, eg caused by a roll change, incoming disturbances are thus detected well before the knife cylinder and can be adjusted at this location. The error at the location of the cut is thus kept small, but in the course of the train - mostly in the form of several partial webs - up to the place of the cut occur more sources of interference that cause a Schnittregisterfehler. Therefore, the cut register error, referred to in the four-roller system as Y ₁₄ , measured by another sensor 5 immediately before the blade cylinder K ₄ and fed to another register controller 3.6, as shown in FIG. 9 for the case a) the complete decoupling. This now provides the setpoint Y * / 13 w , which will change as a result of the default Y _{14 w} in general. The now subordinate control loop for Y * / 13 ensures that the controller 4.5 for Y ₁₄ essentially only needs to correct the disturbances that occur after terminal point 3. The superimposed register control loop is able to work together with all the control variants described under point 1.
The case of multi-lane operation is described in the co-pending patent application PB04640.

In parallel patent application PB04637, the control of the fractional cut register error becomes by overfeeding a non-printing nip disclosed. Furthermore, in this co-pending patent application PB04637 the Connection of the total register error measured on the knife cylinder discloses the control loop for this partial cut register error. In addition, the Control of the position or speed of a knife cylinder to correct the Total register error disclosed in PB04637.

In place of the in the section "regulation of register error at a not printing nip in front of the knife cylinder "under point 3 traction control loop described draft control using the pressure units, the Angular velocity of the cooling unit occur, as described below.

Tension control loop

After the register control via the advance of the clamping point 3 ( K ₃ ) is connected to a change in the web tension F ₂₃ , it can not be ruled out that large disturbances cause too small or too large web tension, which can lead to web breakage. The web tension F ₂₃ must therefore be limited. For this purpose, it is measured by means of a tensile force sensor 8, for example as a measuring roller, measured, fed to the comparison point of a draft regulator 2.1 and compared with the desired value F _{23 w} (see FIG. 10). The tension regulator 2.1 ensures compliance with the desired web tension force F ₂₃ and at the same time enables its paper type-dependent specification by the machine operator, who no longer has to intervene in the overfeed adjustment of the clamping point 3 ( K ₃ ). The draft regulator 2.1 specifies the angular velocity setpoint ω _{2 w} , ie the lead of the cooling unit.

The use of the lead of the cooling unit as a manipulated variable for the force F ₂₃ is possible that when adjusting the angular velocity ω _2, the force F _{23 is} not self-compensating. This is due to the change in paper properties due to the moisture and heat input through the printing units and drying line

Couplings between the controlled variables

The two controlled variables, namely the partial cutting register error Y * / 13 and the tensile force F ₂₃ , are dependent on one another by the structure of the controlled system, ie coupled to one another. If, for example, a setpoint change F _{23 w is} made, the engagement of the draft regulator 2.1 causes a partial cut register error Y * / 13. The register control loop (controller 3.1) now attempts to return this error Y * / 13 to the setpoint value Y * / 13, w , for example the value 0, by means of a speed change ν ₃ , whereby, however, the force F _{23 is} changed again Zugkraftregelkreis responds, etc. (see Fig. 10). This can make the entire system unstable.

decoupling

As a result of the changed by moisture and heat input paper properties when changing the angular velocity ω _2, the change in the web tension F _{12 is} so small that their impact on the following in the direction of transport track sections is negligible. With this neglect simple decoupling algorithms can be derived. A decoupling on the mechanical plane, characterized by the block 2.8 in the forward direction and the block 3.8 in the reverse direction, is shown in Fig. 11. Blocks 2.7 and 3.7 represent the equivalent transfer functions of the closed-loop speed control circuits of terminal points 2 (K2) and 3 (K3). Since such a decoupling on the mechanical level is not possible, this occurs at the level of the electronic drive controls, as in FIG the blocks 2.9 and 3.9 is indicated. The goal is to make Y * / 13 dependent solely on ν ₃ and F ₂₃ solely on ν ₁ .
The tension controller 2.1 and the register controller 3.1 can be designed for example as a PI controller. It is then ensured that both control loops operate dynamically largely unaffected by one another and the predefined setpoint values for the force F ₂₃ and the register error Y * / 13 are assumed without steady-state errors.

The above-described measures for cutting register regulation should not relate only to the application in offset web presses, but can be used in all other printing processes, substrates and Printing machines are used in an equivalent manner, especially in Gravure printing, screen printing, flexographic printing, textile printing, foil printing, metal printing, Label printing machines, textile printing machines, foil printing machines, Illustration and newspaper printing machines etc.

LIST OF REFERENCE NUMBERS

1

Mechanical controlled system with controlled drives

1 a

Mechanical system (controlled system)

1 b

Regulated drives

1.1

Draft regulators

1.2

Drive motor with speed control loop / angle control loop including Current Loop

1.3

Transfer function (additional setpoint for web tension)

1.4

balancing filter

1.5

balancing filter

1.6

angle controller

1.7

Transfer function (decoupling)

1.8

integrating means

1.9

Transfer function (decoupling)

2

control device

2.2

Drive motor with current control loop

2.7

Replacement function of the closed speed control loop

2.8

Algorithm for forward decoupling

2.9

Algorithm for forward decoupling

3 3.1

register controller

3.2

Drive motor with current control loop

3.3

Transfer function (decoupling)

3.4

balancing filter

3.5

DT1

3.6

Cut register control

3.7

Replacement function of the closed speed control loop

3.8

Algorithm for backward decoupling

3.9

Algorithm for backward decoupling

4 4.1

Transfer function (decoupling)

4.2

Drive motor with speed control loop / angle control loop including Current Loop

4.3

balancing filter

4.4

angle controller

5

Sensor for cutting register error

6

Sensor for register error

8th

Sensor for web tension

K ₀

Terminal point 0

K ₁

Clamp 1

K ₂

Clamp 2

K ₃

Clamp 3

K ₄

Clamp 4

K _i

Clamp i

K _k

Nip k

F _ij

Web tension in section i-j

F ₀₁

Input web tension

F _01W

Web tension setpoint

F ₂₃

Web tension between K2 and K3

F ₃₄

Web tension between K3 and K4

F _23W

Web tension setpoint

X _iw

input

V

web speed

V _i

Peripheral speed of the clamping point i

ω _i

Angular velocity / rotational speed of the clamping point i

ω _iw

Angular velocity setpoint

α _i

Angle of the clamping point i

α _iw

Angle setpoint / position setpoint of clamping point i

Y ₁₃ ^*

Partial (section) register error between K1 and K3

Y _13w *

Register setpoint

Y ₁₄

(Total) cut register error

Y _14W

setpoint

R _P

pressure regulator

R _F

Draft regulators

R _Y

register controller

T

dryer

M _i

Drive motor for terminal point i with associated control

p

Pressure of the pneumatic cylinder

Z _T

Changes in the cross section and the modulus of elasticity

i _2W

Setpoint of the torque-generating current for drive 2

i _3W

Setpoint of the torque-generating current for drive 3

literature

[Föl 88] Föllinger, O .: Control Engineering . Heidelberg: Hüthig-Verlag 1988

[Bra 96] Brandenburg, G .; Papiernik, W .: Feedforward and feedback strategies using the principle of input balancing for minimal errors in CNC machine tools. Proc. 4 ^th int. Workshop on Advanced Motion Control, AMC '96 -MIE, Vol. 2, pp. 612-618

Claims (32)

A method for controlling the cut register of a rotary printing press, wherein for controlling the cut register a certain image information or measurement marks of the printed web by means of at least one sensor (5; 6) and the web tension ( F ) by means of at least one further sensor (8) are detected, from the image information for the deviation of the position of the printed image with respect to its desired position relative to the location and time of the cut, ie in particular partial and total cut register error, are determined and thus available as actual values and a control device (2) are supplied by the cut register error and the web tension are decoupled from each other. Method according to Claim 1, characterized in that at least one partial cutting register error ( Y * _{1 i} ) to be controlled is applied at or before a clamping point ( K _i ) and at least one web tensile force ( F _{k -1, k} ) or ( F _{i -1, i} ) are measured at or before another clamping point ( K _k ) or the same clamping point ( K _i ), wherein the clamping points ( K _i , K _k ) are non-printing and in each case in front of the knife cylinder ( K ₄ ), and that these controlled variables - the web tensile force ( F _{k -1, k} or ( F _{i -1, i} ) and the cutting register error (Y ^* _{1 i} ) - by manipulated variables ( ν _{i- 1, i} , ν _i , ν _{k - 1, k} , ν _k , F ₀₁ ) and associated controllers (1.1, 3.1) to desired setpoints ( Y ^* _{1 iw} , F _{k- 1, k, w} F _{i- 1 , i, w} ) are set. A method according to claim 1 or 2, characterized in that the manipulated variable for the cutting register is the lead of a non-printing nip and the manipulated variable for the web tension the lead or position of the printing units, both schemes are implemented by appropriate control circuits, which the normal drive controls be subordinated from current, speed and / or angle control. Method according to one of claims 1 to 3, characterized in that the manipulated variable used is the peripheral speed of the unwinding device which determines the stationary and transient mass flow introduced into the system. A method according to claim 4, characterized in that the peripheral speed is influenced by means of at least one measured value for a web tension, web tension or web elongation, in particular by the position of a force acting on the web F ₀₁ dancer or pendulum roller, or by means of a force F ₀₁ regulating track traction control loop. Method according to one of Claims 1 to 5, characterized in that the manipulated variable for the partial register error ( Y * / 1 k ) is the speed (v _k ) of a clamping point ( K _k ) and the manipulated variable for the web tensile force ( F _{i- 1 , i} ) in a preceding web section, the speed (v _i ) of a terminal point ( K _i , i <k- 1) lying in front of it is. Method according to Claims 1 to 6, characterized in that the manipulated variable for the partial register error ( Y * / 1 k ) is the speed ( ν _k ) of a clamping point ( K _k ) and the manipulated variable for the web tensile force ( F _{k- 1 , k} ) in the same web section, the speed (v _i ) of a terminal point ( K _i , i <k- 1) lying in front of it, wherein when the speed ( v _i ) of this nip changes ( F _{i, i +1} ) in the following Track section may not be self-compensating. A method according to claim 7, characterized in that the manipulated variable for the partial register error ( Y * / 1 k ) the speed (v _k ) of a nip ( K _k ) and the manipulated variable for the web tension ( F _{k -1, k} ) in in particular the speed (ν _{k -1} ) of the clamping point ( K _{k- 1} ) lying in front of it is the same path section, whereby the force ( F _{k -1, k} ) does not self-compensate when the speed ( ν _{k- 1} ) of this clamping point changes may be. A method according to claim 1 to 8, characterized in that the manipulated variable for the partial register error Y * / 1 k, the speed (v _k ) of a terminal point ( K _k ) and the manipulated variable for the web tension ( F _{m -1, m} ) in a subsequent track section is the speed (ν _m ) of a nip ( K _m , m ≥ k + 1). Method according to one of claims 1 to 9, characterized in that prior to the registry error controlling terminal point, such as the turning unit, terminal points decoupling receive additional setpoints obtained (backward decoupling) and that this decoupling for stable operation is mandatory and / or that also all after the register error controlling terminal point, such as the turning unit, lying terminal points decoupling leading additional setpoints obtained (forward decoupling). A method according to claim 10, characterized in that for the partial decoupling in the reverse direction, the specification of the decoupling Voreilungs-Zusatzsottwertes for the nip 2 in the form of an additional speed setpoint is performed and for the nip 1 in the form of a corresponding additional tensile load setpoint at the entrance of the draft regulator via a In accordance with modified transfer function of the closed traction control loop or the specification of the decoupling Voreilungs additional setpoint for the terminal point 1 in the form of a corresponding speed additional setpoint via balancing filter is performed. A method according to claim 10 or 11, characterized in that for decoupling in the forward direction with the output signal ( x ) of a transfer function F _x (1.7) a precontrol of the nip 3 ( K ₃ ) either by means of a corresponding register additional setpoint at the input of the register regulator with the help another transfer function (3.3) or using a Symmetrierfilters (3.4) to the lower speed control loop of this register control loop. A method according to claim 10 or 11, characterized in that the clamping point 4 ( K ₄ ) of the nip 1 ( K ₁ ) is tracked, wherein the output signal ( x ) of the transfer function F _x (1.7) by means of a transfer function (4.1) as an addition -Winkel setpoint on the angle controller (4.4) of the terminal point 4 ( K ₄ ) is performed or the tracking using a Symmetrierfilters (4.3) as a speed additional setpoint at the lower speed control loop (4.2) of the terminal point 4 ( K ₄ ). Method according to one of claims 1 to 13, characterized in that the assignment of controlled variables and manipulated variables including all necessary for this constellation corresponding decoupling and pilot control measures is reversed. Method according to one of claims 1 to 14, characterized in that the cut register error is measured immediately before the knife cylinder and controlled by a register controller, which is superimposed on the register controller of the nip 3 ( K ₃ ). A method according to claim 1 or 2, characterized in that the web tension assumes its setpoint, which is within a prescribed range and the cut register error is corrected to its desired value, in particular to the value zero. Method for controlling the cutting register error of a rotary printing press, wherein at least one web tensile force ( F _{k -1, k} ) or ( F _{i -1, i} ), at least a partial cut register error ( Y * _{1 i} , Y * / 1 k ) and the Total Cut Register Errors ( Y * / 14) are controlled variables and these are controlled by suitable manipulated variables, namely velocities and / or angular positions of non-printing and / or printing nips (ν _{i -1, i} , ν _i , ν _{k - 1, k} , ν _k , ν ₁ , ν ₄ ), by means of control loops by means of associated controllers (1.1, 3.1) decoupled from each other on the basis of corresponding desired values ( Y * / 1 i, w , Y * / 1 k, w , F _{k- 1 , k, w} , F _{i- 1 , i, w} ) are set so that each of the controlled variables, ie at least one web tensile force and at least one partial cut register error or the total cut register error, assumes its setpoint, which is within a prescribed range, the part Cut register error and / or the total cut register error, for example on d value zero is corrected. A method according to claim 17, characterized in that at least a partial cut register error (Y ₁₃ ^* ) and the total cut register error (Y ₁₄ ) by sensors (5, 6), which evaluate a specific image information or measurement marks of the printed web by means of at least one sensor (5; 6) and the web tensile forces ( F _{k -1, k, w} , F _{i -1, i, w} ) are detected by at least one further sensor (8) and fed to a control device (2). Method according to one of claims 1 to 18, characterized in that the manipulated variable for the cutting register (Y ₁₃ ^* ) is the lead (angular velocity ω _{3 w} ) of a non-printing nip, in particular the lead of the turning unit (K3), and the manipulated variable for the web tension in a preceding or in the same path section is the lead (angular velocity ω _{2 w} ) of the cooling unit (K2), both regulations being realized by appropriate control circuits to which the normal drive controls from current, speed and / or angle control (2.2 2.7, 3.2, 3.7) (FIGS. 10 to 12). Method according to one of Claims 1 to 19, characterized in that the decoupling takes place with the aid of analytically computable transfer functions (2.8, 3.8) according to a mathematical model of the printing press. A method according to claim 20, characterized in that the plastic deformation of the paper web is used when changing the lead (ω _{2 w} ) of the cooling unit (K2), in particular simple decoupling algorithms (2.8, 3.8) can be deduced. Method according to Claim 21, characterized in that the simple decoupling algorithms (2.8; 3.8) calculated for the mechanical plane are implemented on the electronic level (2.9; 3.9) of the regulated electric drives. Method according to one of Claims 1 to 22, characterized in that decoupling algorithms in which open integrators with the integration time constant (7) occur are replaced by first-order delay elements with the time constant (7), whereby easy commissioning is made possible. Method according to Claims 1 to 23, characterized in that the controlled variables coupled by the controlled system, ie the regulated partial cut register error (Y ₁₃ ^* ) and the regulated force ( F ₂₃ ) are determined by the decoupling algorithms (2.9; 3.9) and the algorithms of the controllers (2.1, 3.1) assume their specified setpoints without permanent control errors. Method according to Claims 1 to 24, characterized in that the control circuit for the web tension ( F ₂₃ ) is equipped with a limitation of the angular velocity setpoint ( ω _{2 w} ) in such a way that the force in front of the nip (K2) regulating the register error is adjustable, prescribed Limits is kept. Method according to Claims 1 to 25, characterized in that the control circuit for the register error (Y ₁₃ ^* ) is equipped with a limitation of the angular speed setpoint (ω _{3 w} ) such that the lead of the clamping point (K3) is kept within adjustable, prescribed limits , Method according to one of claims 19 to 26, characterized in that the assignment of controlled variables and manipulated variables including all necessary for this constellation corresponding decoupling and pilot control measures is reversed. Method according to one of claims 19 to 27, characterized in that the total cutting register error (Y ₁₄ ) is measured immediately before the knife cylinder and controlled by a register controller (3.6), which is superimposed on the register controller of the nip 3 ( K ₃ ). Device for controlling the cutting register, in particular according to claim 1 to 28, on a rotary printing machine whose clamping points ( K ₁ to K ₄ ) with drive motors with associated current, speed and optionally angle control are independently drivable and in which the cut register ( Y ₁₄ ) and / or associated further partial register deviations ( Y * / 13, Y * / 1 i , Y * / ik ) on or in front of a knife cylinder ( K ₄ ) and / or on or in front of one or more of these knife cylinders ( K ₄ ) upstream clamping points ( K _i , K _k , K ₁ to K ₃ ) can be detected by means of at least one sensor (5, 6) via a specific image information or measuring marks of the printed web, the web tension force ( F ) being measured by means of at least one further sensor (8). detectable and this by the sensors (5; 6; 8) detected register deviations ( Y * / 13, Y * / 1 i , Y * / i k ) and web tensile forces ( F _jk ) for influencing the cutting register error ( Y ₁₄ ) a rule - and / or r control device (2) for changing angular positions or peripheral velocities (ν ₁ , to ν ₃ , ν _i , ν _k ) of the respective terminal point ( K ₁ to K ₃ , K _i , K _k ) can be fed, wherein the web tensile force (F _jk ) in one path section (jk) and the register _error ( Y * / 1 k ) in another or the same _path section are independently adjustable by respective set values ( F _jkw , Y * / 1 kw ), including a man-machine interface, in particular a control room, with appropriate visualization is provided. Apparatus according to claim 19, characterized in that an unwinding device (K0) is controllable by means of dancer rollers or web tension control loops such that with the aid of the circumferential speed (ν ₁ ) of the clamping point ( K ₁ ) or with the aid of the web tension ( F ₀₁ ) of the transient and stationary , introduced into the system mass flow is changeable. Apparatus according to claim 19 or 20, characterized in that the sensors (5; 6; 8) and associated evaluation devices at the nominal speed of the printing press information about the register or the register error ( Y ₁₄ ; Y * / 13; Y * / 1 i ; Y * / ik ) and provide the web tensile force ( F _{k -1, k} or F _{i - 1, i} ) in minimal time and are executed with interfaces which limit the register errors ( Y ₁₄ ; Y * / 13; Y * / 1 i ; Y * / ik ) and web tensile forces ( F _{k -1, k} or F _{i -1, i} ) via field buses, Ethernet or other communication buses or communication interfaces. Device according to one of claims 19 to 21, characterized in that the control and / or control device (2) as a central computer, preferably in the control room, or as an embedded computer, preferably in a control or control cabinet, or functionally decentralized in the respective inverter devices is realized and all information (actual values, setpoints, Regelalgorythmen) can be processed in real time.

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