EP0917954B2 - Device and method for producing a reference value of a single position in a printing process - Google Patents

Description

The present invention relates generally to position determination in printing systems and to a control system for a printing press that controls relative positions of drive units in the printing press.

As of conventional web-fed rotary printing machines, z. For example, if the press used for newspaper printing has traditionally not expected high quality or sharpness printing, the print quality tolerance tolerance threshold has been relatively high in the printing industry. However, it is increasingly desired to improve the quality and sharpness of printed products, so that there is a need for printing presses that can deliver high quality and sharpness printed products. Normally, the production of high quality products involves a reduction in printing speed. Nevertheless, it is desirable in the printing industry that printing machines can be operated at high speeds. However, it has been found that it is a very difficult task to meet the requirements for quality, image sharpness and speed at the same time.

A conventional printing press usually consists of a number of printing units. The relative positions of drive shafts of these printing units must be accurately controlled to ensure accurate registration of the various printing units so that errors such as print register errors, web tension errors, web-to-web register errors, and / or signature section errors can be prevented. Namely, such errors occur increasingly at high printing speeds.

In certain printing presses, each group of printing units has a drive unit with a drive shaft connected to and driven by an output shaft of an electric motor for that group. A speed control unit generates a speed control signal for controlling the rotational speed of the output shaft of the electric motor. Other groups of printing units as well as non-printing jobs in the printing press can also have drive units. Usually, a drive unit of the machine is designated as the "master drive" which receives a signal indicative of the desired speed of the paper web passing through the printing press. This signal of the desired speed is sent to the speed control element of the master drive for controlling the speed of the drive shaft of the pilot drive. Signals indicating the actual speed and position of the master drive shaft are transferred to the other drive units called "slave drives". The speed control member of each slave drive unit transmits a speed control signal based on the actual position of the follower drive shafts and the master drive shaft to the follower electric motor which causes the drive shaft of the respective follower to follow the speed and position of the master drive shaft , Ideally, the drive shaft of each slave drive unit is in the same position and at the same speed as the drive shaft of the master drive unit.

DE 41 37 979 describes a drive for a printing press with multiple printing units, wherein the individual printing units or groups of documents are mechanically decoupled from each other, each printing unit or each group of printing units a drive motor is assigned and arranged at each printing unit or at each printing group a device for speed and / or rotation angle determination is. It is further provided a device for angle control, which measures an allowable angular deviation of the individual printing units or groups of printing groups from a predetermined desired angle value such that it is minimal, at least at the angular position at which a sheet transfer takes place, is minimal. In this case, the respective angular position of two printing units is supplied to a microcomputer, which further receives from a setpoint input a speed setpoint and an angle setpoint at which the sheet transfer is to take place, the microcomputer calculates torque reference values based on an angular difference between the predetermined angle setpoint and the angular positions of the printing units, that the permissible angle of rotation deviation of the respective printing units from the predetermined target value during sheet transfer is minimal.

DD 115 069 discloses a method for starting register control on printing machines with multiple printing units, wherein continuously the position of elements, such as gears is scanned at least two printing units by pulse generator, the phase position or phase shift of a pulse with respect to the other pulse, the reference pulse, electronically determined by size and direction is and the determined value for adjusting an actuator is evaluated.

There are many types of control devices to control the position of the drive shaft of a follower drive relative to the position of the drive shaft of a master drive, such as phase locked controllers and constant velocity controllers. A synchronizer typically includes a resolver to convert the angular position of the follower drive shaft to an electrical output. The position of the follower drive shaft relative to the position of the idler shaft is then controlled in accordance with the electrical output signal generated by the synchronizer. Control devices with a control compensation, such as "positive control", "speed setpoint" and "dp / dt pilot control" are also known. In addition, a "Type 3" controller can also be used which integrates a position error signal (ie, a difference value in the positions of the follower drive shaft and the idler shaft) twice. Such a regulator is in US 5,049,798 , issued September 17, 1991.

Fig. 1 1 shows a conventional printing machine 10 with draw-in units 12 and 14, a group 207 of printing units 200-206 and a group 23 of printing units 16-22, a dryer 24, cooling units 25 and 26, and folding units 28 and 30. Each of the groups of printing groups 207 and 23 and Folding units 28 and 30 has a drive unit. From a master reference signal source 32, a signal, ie, a speed command signal is generated which indicates to the drive unit of the group 207 a desired press speed. The drive unit of group 207 is designated as a master drive unit. The other drive units belonging to group 23 and the folding units 28 and 30 are designated as follow-on printing units which follow the position and speed of the master printing unit.

Fig. 2 shows details regarding the internal components of the drive units in the groups 207 and 23 and the folding units 28 and 30 and connections between the drive units and the reference reference signal source 32. Specifically, the speed command signal from the reference reference signal source 32 is input to a speed controller 210 of the master drive unit in the group 207 to control the speed of the motor 260. The speed command signal may be an analog or a digital signal. A position encoder 230 determines the actual position value of a drive shaft 240 that is driven by the motor 260 of the master drive unit. Alternatively, since position information output by position encoder 230 may be used to determine speed information, position encoder 230 may also return an actual value to speed controller 210 to ensure that the actual speed of drive shaft 240 corresponds to the master drive unit's desired speed ,

The speeds and positions of the drive shafts 242-246 of the slave drive units are controlled to match the speed and position of the drive shaft 240 of the master drive unit. This is achieved by using the speed of the drive shaft 240 of the idler unit together with the feedback regarding the positions of the drive shafts 242-248 of the follower drive units relative to the position of the idler drive shaft 240.

As in Fig. 2 As shown, the follower drive units include motors 262-266 that drive the drive shafts 242-246. Position encoders 232-236 determine the actual positions of the drive shafts 242-246 and send respective feedback signals to controllers 222-226 which indicate the determined positions. As mentioned above with respect to the position encoder 230 of the master drive unit, the information generated by the position encoders 232-236 can be used to determine both the velocities and the positions of the corresponding drive shafts 242-246. The output signal generated by the position encoder 230 indicative of the actual position of the idler drive shaft 240 is sent as a reference position signal to the sliders 222-226 of the follower drive units of the printing group 23 and the folders 28 and 30, as shown in FIG Fig. 2 shown. The regulators 222-226 compare the output signal of the position encoder 230 of the master drive unit with the output signals of the position encoders 232-236 and, based on this comparison, send command signals to the speed controllers 212-216 to control the speed of the motors 262-266 so that the Drive shafts 242-246 follow the drive units of the speed and position of the drive shaft 240 of the master drive unit.

According to one embodiment of the position explorer 230, this generates a pulse for each angular increase in the rotating drive shaft 240 of the master drive unit. Thus, as the drive shaft rotates, the position encoder 230 generates a stream of pulses. The number of pulses generated by the position encoder 230 during a time interval indicates by what amount the drive shaft 240 has changed position during this time interval. The average speed during the time interval can be easily determined by dividing the value of the position change by the duration of the time interval.

The angular increment corresponding to a pulse is fixed so that the position encoder 230 produces 2,048 pulses during each complete revolution. The position encoder 230 is monitored and the pulses generated by it are counted by means of a counter, not shown. The counter usually returns to zero at the end of a revolution after counting up to 2,048. In some embodiments, a different number of pulses per revolution is decisive and in other embodiments, the counter jumps back to zero less frequently than after each revolution. The position encoders 232-236 are implemented in the same way as the position encoder 230. The positions of encoders 230-236 may be synchronized by simultaneously resetting the corresponding counters to zero, e.g. B. when the web moves at a slow and constant speed through the printing press. Thereafter, any value difference in the counters means a phase or position difference. For example, if the counter corresponding to the position coder 230 of the master drive unit indicates a value of 1,000 at a certain time, and the value of the value associated with the position coder 232 At this time, the follower drive unit 242 of the follower drive unit remains behind the position of the drive shaft 240 of the idler unit by 205 angle increment points or by 36 degrees. Computer software accurately tracks existing phase differences when the meters are reset, even if they are larger than a complete revolution. In the in Fig. 2 As shown, each of the controllers 222-226 has a counter, not shown, which counts the pulses generated by the position encoder 230 of the master drive unit and a counter, not shown, which counts the pulses generated by one of the position encoders 232-236 of the slave drive units. In some implementations, the counters are located within or near the corresponding position encoders.

Although the regulators 222-226 are designed to synchronize the speeds and positions of the drive shafts of the slave drive units with those of the drive shaft 240 of the master drive unit, they can not be used for problems caused by mechanical disturbances or control errors on the drive shaft 240 of the master drive unit. Such control errors are on the. Subsequent drive units transmitted and there is a tendency that these errors are repeated. Thus, a control error on the master drive shaft can greatly affect the operation of slave drive units. For large disturbances, the controller power is interrupted or at risk, so that problems in printing operation, eg. B. may occur due to register errors.

Events that can cause speed and position disturbances during printing include, for example: B. a "blanket wash". When washing a blanket, any accumulated dirt and lint from the blanket roll in the press is washed off or brushed off. When a blanket wash is performed on a master drive unit, disturbances in the speed and position of the drive shaft 240 of the master drive unit may occur, which are then transmitted to the slave units, so that the smooth printing operation of the machine is no longer possible and waste and a lower print quality consequences are. Other processes in the printing operation can also cause interference, such. B. when a new web is connected to the existing web or when the web is cut during the folding process.

Since errors at a leader are transmitted to the sequential units, usually a unit of the printing press at which the fewest errors and the smallest error sizes occur is selected as the leader. If z. B. a printing machine feeder units, printing units, drying units, chill roll units and folding units comprises, as in Fig. 1 Usually, one of the printing units instead of one of the folding units is selected as a guide unit, because the cutting operation on a folding unit can cause a much larger transitional disturbance than the blanket washing operation in a printing unit.

Even if the operating persons try to keep the operation of printing presses as smooth as possible and thus to minimize the transitional disturbances occurring at the leading drive unit, they still occur. When interference occurs, filtering networks and reference dead zones are used until the disturbances are identified and corrected. The waste resulting from the disturbances and lower print quality are taken for granted. However, it is desirable to provide a printing machine in which the effects of transient disturbances are reduced or eliminated, so that improved print quality and less waste can be achieved even at higher machine speeds.

The present invention relates to a method and apparatus for enabling trouble-free speed and position reference signals to drive units in a printing machine, e.g. B. print works to send.

Furthermore, from the DE 43 22 744 a device and a method according to the preambles of claims 1 and 12 known.

A device according to the invention for controlling the printing process of a printing press is specified in claim 1.

There is provided a single position reference unit which receives a signal indicative of the desired speed of a web passing through the printing machine. The single-position reference unit generates signals representing an error-free reference speed and an error-free reference position, and the printing machine drive units, e.g. As the printing units, control, without errors that result from the associated with mechanical disturbances in the printing operation transition states are increased. The same reference signals can go to all drive units. Alternatively, separate reference signals may be generated for each drive unit, and inaccuracies occurring between the individual reference signals generated for the various drive units may be corrected by error correction circuitry.

An inventive method for controlling the printing process of a printing press is specified in claim 12.

The present invention will become more apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, which are given below.

Fig. 1

ein Blockdiagramm einer Druckmaschine des oben beschriebenen Standes der Technik;

Fig. 2

ein Blockdiagramm, das die interne Konstruktion einiger Elemente der in Fig. 1 dargestellten Druckmaschine zeigt;

Fig. 3

ein Blockdiagramm einer Druckmaschine gemäß einem ersten Ausführungsbeispiel der Erfindung;

Fig. 4

ein Blockdiagramm, das die interne Konstruktion einiger in Fig. 3 dargestellten Druckwerke zeigt;

Fig. 5

ein Blockdiagramm einer Druckmaschine gemäß einem zweiten Ausführungsbeispiel der Erfindung;

Fig. 6.

ein Blockdiagramm einer Druckmaschine gemäß einem dritten Ausführungsbeispiel der Erfindung;

Fig. 7

ein Blockdiagramm einer Druckmaschine gemäß einem vierten Ausführungsbeispiel der Erfindung;

Fig. 8

ein Blockdiagramm, das die interne Konstruktion von in Fig. 7 dargestellten Reglern zeigt.

Show it:

Fig. 1

a block diagram of a printing press of the prior art described above;

Fig. 2

a block diagram showing the internal construction of some elements of the Fig. 1 illustrated printing machine shows;

Fig. 3

a block diagram of a printing machine according to a first embodiment of the invention;

Fig. 4

a block diagram showing the internal construction of some in Fig. 3 shown printing works shows;

Fig. 5

a block diagram of a printing press according to a second embodiment of the invention;

Fig. 6.

a block diagram of a printing press according to a third embodiment of the invention;

Fig. 7

a block diagram of a printing press according to a fourth embodiment of the invention;

Fig. 8

a block diagram showing the internal construction of in Fig. 7 shown controls.

Fig. 3 shows an embodiment of a printing press, in which elements with those of in Fig. 1 shown printing machine are identical, have been identified by the same reference numerals. According to the embodiments of the present invention, none of the printing units of a printing press is characterized as master printing unit. As in Fig. 3 As shown, a single position reference unit 500 is provided which receives from a reference reference signal source 32 a signal representing a desired printing press speed and sends a single position reference signal to each printing unit. Unlike in the Fig. 1 and 2 Each of the printing units 200-206 and 16-22 and each of the folding units 28 and 30 has a separate drive unit.

If that in the 3 and 4 embodiment shown has a drive unit for each printing unit, it is obvious to the expert that the invention can also be realized in a printing press with only one drive unit for all printing units or for each group of printing units. A single drive unit for a group of printing units can be controlled in the same way as a drive unit for a single printing unit is controlled in the embodiments described herein. Fig. 4 shows details of the printing press the Fig. 3 ie, internal components of the print engines 200-206 and interconnections between these print engines, the single-position reference unit 500, and the routing reference signal source 32. In contrast to the in Fig. 2 the components shown, the drive unit for the printing unit 200 is equipped with a controller 420; Thus, the internal construction of this drive unit is the same as that of the other drive units shown in the printing units 202-206. Each of the regulators 420-426 in the printing units 200-206 receives the single position reference signal from the single position reference unit 500. The single position reference signal may be an analog or a digital signal.

The speeds and positions of the drive shafts 440-446 of the drive units are controlled to match the reference speed and position indicated by the single position reference signal, using the reference speed, along with feedback on the positions of the drive shafts 440-446 of the drive units relative to the reference position.

As in Fig. 4 As shown, the drive units include motors 460-466 which drive the drive shafts 440-446. Position encoders 430-436 determine the actual positions of the drive shafts 440-446 and send respective feedback signals to the regulators 420-426 indicating the determined positions. As described above with respect to the position encoder 230 of FIG Fig. 2 As mentioned, the information outputted by the position encoders 430-436 may be used to determine both the velocities and the positions of the corresponding drive shafts 440-446. The regulators 420-426 compare the single-position reference signal with the output of the position encoders 430-436 and, based on this comparison, send command signals to the velocity control units 410-416 for controlling the speed of the motors 460-466 so that the drive shafts 440-446 of FIG Drive units follow the speed and position indicated by the single position reference signal. Thus, the drive shafts 440-446 are not affected by transient mechanical disturbances in the printing operation. The printing units 16-22 and the folding units 28 and 30 are of the same configuration and offer the same advantages.

Fig. 5 FIG. 12 shows a second embodiment of the invention having an exemplary internal configuration of the single position reference unit 500 that includes a vibrator 502, a divider / multiplier 504, and a filter / amplifier 506. The vibrator 502 generates a time signal which is divided or multiplied in correspondence with the signal received from the reference reference signal source 32 representing the desired printing press speed. The filter / amplifier 506 filters noise from the signal output by the divider / multiplier 504 and sends the resulting single position reference signal to the regulators of the printing units. The filter / amplifier 506 also amplifies the signal in any manner desired by the user so that it is compatible with the regulators in the printing units. The single-position reference unit 500 may be realized by using only electronic components, it may be a solid-state device or an analog-acting device.

Each pulse of the single-position reference signal output from the single-position reference unit 500 represents an increase in the angle by which a drive shaft must move. The angle increment has a predetermined value. Thus, the number of pulses occurring in the single-position reference signal within a time interval indicates a change in the reference position during this time interval, and the frequency of the pulses indicates a reference speed or reference angular velocity.

Fig. 5 16 shows in the printing unit 200 a counter / sampler 508 which is connected to the controller 420 and the position encoder 430 and may be used to supplement the processing capability of the controller 420 and / or to provide information from the position encoder 430 in a more useful form. For example, counter / sampler 508 may generate a signal indicative of the number of position increments by which drive shaft 440 has moved during a time interval, ie, the number of position changes during the time interval.

The controller 420 includes a counter (not shown) that counts the pulses received from the single position reference unit 500 that can be compared with the pulses counted by the counter / sampler 508 to determine a possible phase difference between the reference position and the position the drive shaft 440 determine. Alternatively, the counter may also be mounted within the divide / multiply device 504 in the single position reference unit 500 so that the signal output of the unit 500 is a pulse count. The controller 420 receives a delay equalization signal to compensate for unwanted signal delays or system inaccuracies. For example, if printing units are located at different distances from the single-position reference unit and / or connected to a single-position reference unit using different signal transmission paths, the same signal will be output from the single-position reference unit due to the characteristic differences in the Signal transmission paths, z. B. the length, arrive at different times at the printing units. Of course, this configuration applies equally to the printing units 202-206 and 16-22 and to the folding units 28 and 30.

Fig. 6 FIG. 10 shows a third embodiment of the invention including a configuration of the single position reference unit 600 that includes a motor 668, a drive shaft 648, a position encoder 638, a speed control unit 618, and a controller 628. The internal construction of the single-position reference unit 600 is similar to that used in the printing units 200-206 of FIG Fig. 4 shown, but with some differences. First, the drive shaft 648 is not associated with any of the operations in the printing press and thus is not subject to undesirable mechanical disturbances in the operation of the printing press, such as blanket washes. The drive shaft 648 may, for. B. can be connected to an operation (not shown) that has straightforward, predictable behavioral characteristics and is free of transient disturbances that could cause problems in engine operation. Second, the controller 628 receives the velocity command signal indicative of the desired press speed from the reference conductive source. Third, the signal output from the position encoder 638 is the single position reference signal which is sent to the regulators 420-426 of the print engines 200-206. The motor 668 may be selected independently of other motors used in the printing press. For example, engine 668 may be smaller than engines 460-466 and an auxiliary engine.

The controller 628 of the single position reference unit 600 controls the speed control unit 618 by maintaining the speed of the drive shaft 648 as precisely as possible by means of a speed feedback to indicate the desired speed. In contrast, regulators 420-426 control the respective speed control units of printing units 200-206 so that drive shafts 440-446 closely track the speed and position of drive shaft 648.

Fig. 7 shows a fourth embodiment of the invention. Here, the reference reference signal source 32 sends a speed command signal representing the desired press speed directly to the controllers 720, 822, 724, and 726, which respectively correspond to the print engines 200-206. The single position reference unit is actually composed of components that are inside the controllers and connections between the controllers. That is, each of the controllers internally generates a single position reference signal based on the speed command signal from the reference reference signal source 32. In each controller, the single-position reference signal is compared with the drive shaft speed and the position information generated by the position encoder of the corresponding printing unit. Based on this comparison, the controller generates a command signal that is input to a corresponding speed control unit so that the drive shaft follows the reference speed and position indicated by the single position reference signal.

To compensate for inaccuracies arising in a period between single position reference signals generated by different controllers and to avoid problems in the printing process that result in such inaccuracies, the single position reference signals generated in the various controllers can be periodically corrected or standardized. In this embodiment, the printing unit 200 is selected as a standard unit and the signal 700 output from its position encoder 430 is used by all other printing units as a standard to which the single position reference signal of each of the printing units is periodically adjusted. According to the embodiments, the single position reference signals are corrected or standardized at a time when the standard selected printing unit is not affected by transient disturbances.

This concept can also be used, for example, if the invention is integrated into an existing printing machine which, due to initial structural restrictions, can not transmit the same single-position reference signal to all its drive units.

Fig. 8 shows the internal construction of the controller 822 the Fig. 7 , As in Fig. 8 1, a vibrator 800 generates a time signal in a manner similar to that in FIG Fig. 5 The time signal is sent to a divide / multiply unit 802, which divides or multiplies the time signal based on the velocity command signal received from the reference source 32 via the line 304, and also divides the pulses of the divisor multiplied time signal counts. A signal setting unit 804 filters noise from the pulse count signal output from the divide / multiply unit 802 and amplifies the signal accordingly. The signal setting unit 804 may also set the signal to be synchronized with the standard signal 700. The signal output from the signal setting unit 804 is a single position reference signal for the printing unit 202 and is sent to a position register 808. The position register 808 also receives a signal from a counter 806; This signal indicates the detected number of pulses that the counter 806 has received from the position encoder 432. As with the counter / sampler 508 in FIG Fig. 5 is shown, the counter 806 may generate a signal indicative of the number of position increments by which the drive shaft 442 has moved during a time interval, ie, the number of position changes during the time interval.

The position register 808 compares the signals sent from the counter 806 and the signal setting unit 804. The signals each represent a change in the position of the drive shaft 442 and a change in the reference position during a time interval, and also indicate the reference speed and the speed of the drive shaft 442. Based on this comparison, the position register 808 generates a command signal which is sent to the speed control unit 412, according to the general principles of well-known control functions and, for example, in the controller 22 of FIG Fig. 2 shown printing press of the prior art is realized.

An exemplary embodiment of a circuit for correcting or standardizing the single position reference signal generated in the controller 822 includes a counter 818, a comparator 812, an error detector 810, an error compensator 814, and a correction value limiter 816. The counter 818 operates in the same way as FIG Counter / scanner 508 in Fig. 5 and the counter 806. The printing unit 200 is selected as the standard printing unit. Thus, the counter 818 detects the pulses received from the position encoder 430 of the standard printing unit 200 and generates a signal indicative of the number of position increments by which the drive shaft 440 has moved during a time interval, that is, the number of position changes during the time interval.

The signal output from the counter 818 and the single-position reference signal from the signal adjuster 804 are input to the comparator 812, which compares the two signals and generates an error signal based on this comparison. The signal output from the comparator 812 is input to the error detector 810 which detects the presence and magnitude of the error between (a) the output signal of the counter 818, d. H. the position and velocity of the drive shaft 440 of the standard printing unit 200, as indicated by the position encoder 430, and (b) the reference speed and position, as represented by the output from the signal setting unit 804 single position reference signal detected. The error detector 810 generates a signal indicative of the determined error and the signal is input to an error compensator 814 which generates a control signal causing the signal adjuster 804 to correct the single position reference signal or to the position and velocity of the drive shaft 440 of FIG Standard printing unit 200. A correction value limiter 816 may be connected to the error compensator 814 and the signal adjuster 804 to slow down the correction process by restricting the output signal of the error compensator 814.

Alternatively, the components of each regulator generating a single position reference signal for the drive unit corresponding to the controller may be located outside the controller. For example, controller 822 may include counter 806 and position register 808 and receive an output signal from position encoder 432 and another output signal from signal adjuster 804. Components such as the vibrator 800, the divide / multiply unit 802, the signal setting unit 804, the comparator 812, the error detector 810, the error compensator 814, the correction value limiter 816 and the counter 818 may be disposed at any position as long as they are properly connected and the output of the signal setting unit 804 goes to the controller 822, the lead reference signal 304 goes to the divide / multiply unit 802, and the standard position encoder signal 700 goes to the counter 818.

The further printing units 204, 206 may be of the same construction and be operated in the same way as the printing unit 202. If the configuration of the Fig. 8 for example for the in Fig. 2 The printing press group 23 and the folding units 28 and 30 of the prior art shown in FIG Fig. 2 shown printing machine may have the same construction as the printing unit 202th

LIST OF REFERENCE SIGNS

16

Printing unit ( Fig. 1 )

18

printing unit

20

printing unit

22

printing unit

28

folding unit

30

folding unit

32

Leitbezugssignalquelle

200

Printing unit ( Fig. 7 )

202

printing unit

204

printing unit

206

printing unit

230

Position encoder ( Fig. 2 )

410

Speed control unit ( Fig. 4 )

412

Speed control unit

414

Speed control unit

416

Speed control unit

420

regulator

422

regulator

424

regulator

426

regulator

430

position encoder

432

position encoder

434

position encoder

436

position encoder

440

drive shaft

442

drive shaft

444

drive shaft

446

drive shaft

460

engine

462

engine

464

engine

466

engine

500

Single Position Reference Unit ( Fig. 5 )

502

vibrator

504

Dividier- / multiplier

506

Filter amplifier unit

508

Counter / scanner

600

Single Position Reference Unit ( Fig. 6 )

618

Speed control unit

628

regulator

638

position encoder

648

drive shaft

668

engine

700

Signal of position encoder 430 ( Fig. 7 )

720

regulator

724

regulator

726

regulator

800

Vibration generator ( Fig. 8 )

802

Dividier- / multiplier

804

Signaleinstelleinheit

806

counter

808

position register

810

error detector

812

comparator

814

Fehlerkompensator

816

Correction value limiter

818

counter

822

regulator

Claims (18)

1. Device for controlling the printing process of a press having a first and at least a second drive unit with a respective motor (460-468) and a respective drive shaft (440-448);
   a first and at least a second position encoder (430-436; 638), which in each case determine the current position of the respective drive shaft and generate at least one respective position encoder signal;
   a first and at least a second speed control unit (410-416, 618), which control the speed of the respective drive shaft (440-446, 648); and
   a first regulator (420-426, 628, 720-726, 822); and at least a second regulator (420-426, 628, 720-726, 822), the regulators (420-426, 628, 720-726, 822) sending to the respective speed control unit (410-416, 618) a control signal based on at least one single-position reference signal and the respective position encoder signal,
   characterized in that
   the device has a single-position reference value unit (500), which generates the at least one single-position reference signal on the basis of the desired press speed, which signal is free of disturbances triggered by the printing operation, and sends the said signal to the first and the at least second regulator (420-426, 628, 720-726, 822), and in that the single-position reference signal and the position encoder signals (430-436, 638) each comprise a number of pulses, and in that the control signal generated by the respective first and at least second regulator (420-426) is also based on a delay compensating signal for a signal path link between the single-position reference value unit (500) and the respective first and at least second regulator (420-426).
2. Device according to Claim 1, characterized in that the single-position reference signal comprises at least one reference speed signal and a reference position signal.
3. Device according to Claim 1 or 2, characterized in that the single-position reference value unit comprises an oscillator (502) for generating a reference signal and a frequency divider unit (504) for dividing the reference signal based on the desired press speed.
4. Device according to one of the preceding claims, characterized in that the first and the at least second drive unit further each comprise a counter (508), which is operatively connected to the respective first and at least second position encoder (430-436) and the respective first and at least second regulator (420-426), in order to register a change in the position of the respective drive shaft (440-446) during a sampling time.
5. Device according to Claim 1, characterized in that the single-position reference value unit (500) comprises the following:

   a motor (460) separate from the press and having an output drive shaft;

   a speed control unit (410), by which the speed of the output drive shaft is controlled;

   a position encoder (430), which generates a signal indicating the position of the output drive shaft, the position encoder signal being the single-position reference signal;

   and a regulator (420), which sends to the speed control unit a control signal which is based on the single-position reference signal and the desired press speed.
6. Device according to one of the preceding claims, characterized in that a master reference signal source (32) is also provided, in order to send a signal representing the desired press speed to the single-position reference value unit (500).
7. Device according to Claim 6, characterized in that the signal generated by the master reference signal source is a digital signal.
8. Device according to one of the preceding claims, characterized in that the single-position reference value unit (500) is an electronic module.
9. Device according to Claim 1, characterized in that the single-position reference value unit (500) generates a large number of single-position reference signals based on the desired press speed, and in that the device further comprises:

   a large number of drive units (460-466) with a respective drive shaft (440-446); a speed control unit (410), which controls the speed of the drive shaft (440); a position encoder (430), which generates a signal indicating the position of the drive shaft (440); and a regulator (720), which sends a control signal to the speed control unit which is based on the signal from the position encoder and on at least one of the large number of

   single-position reference signals.
10. Device according to Claim 9, characterized in that the single-position reference value unit (500) comprises at least one error correction circuit in order to correct at least one of the single-position reference signals, which are based on the output from a position encoder of a drive unit designated from a large number of drive units.
11. Device according to Claim 9 or 10, characterized in that one of the large number of drive units (460-466) is designated master drive unit and others from the large number of drive units (460-466) are designated follower drive units; and in that the single-position reference value unit (500) for each of the follower drive units comprises the following:

    an oscillator (502), which generates a signal;

    a frequency divider unit (504), which generates a signal by dividing the oscillator signal, which is based on the desired press speed;

    a pulse addition/subtraction unit for generating the single-position reference signal by changing the number of pulses in the signal generated by the frequency divider unit (504);

    a comparator (812), which compares the single-position reference signal generated by the pulse addition/subtraction unit with the signal generated by the position encoder of the master drive unit and generates a signal on the basis of this comparison;

    an error detector (810), which detects an error between the single-position reference signal generated by the pulse addition/subtraction unit and the signal generated by the position encoder of the master drive unit; and

    an error correction unit, which generates a control signal on the basis of the detected error in order to control the pulse addition/subtraction unit.
12. Method for controlling the printing process of a press, having the following steps:

    determining the position of a respective drive shaft (440-446) of a first and at least a second drive unit (460-466) of the press by using a respective position encoder (430-436, 638) and sending a respective position encoder signal to a regulator (420-426, 628, 720-726, 822); and controlling the rotational speed of the respective drive shaft (440-446) by using a respective speed control unit (410-416, 618),

    characterized by
    generating a single-position reference signal based on the desired press speed, which signal is free of disturbances triggered by the printing operation and comprises a number of pulses;
    sending the single-position reference signal to respective regulators (420-426, 628, 720-726, 822); and
    sending a respective signal based on the single-position reference signal and the respective position encoder signal, comprising a number of pulses, to the respective speed control unit (410-416, 618), and characterized in that the control of the rotational speed of the respective drive shaft (440-446) is also based on a delay compensating signal.
13. Method according to Claim 12, characterized in that the step of generating the single-position reference signal comprises the following:

    generating a time-based signal having a predetermined frequency;

    dividing the time-based signal based on the desired press speed;

    filtering noise out of the time-based signal; and amplifying the time-based signal.
14. Method according to Claim 12 or 13, characterized in that this further comprises the step of determining a change in the position of the respective drive shaft (440-446) during a sampling time.
15. Method according to Claim 12, characterized in that the production of a single-position reference signal comprises the following:

    determining the position of a drive shaft (440-446) separate from the press;

    generating the single-position reference signal on the basis of the drive shaft position determined; and

    controlling the rotational speed of the drive shaft (440-446) on the basis of the single-position reference signal and the desired press speed.
16. Method according to Claim 12, characterized by
    determining the drive shaft position of each of a large number of drive units (460-466);
    generating at least one single-position reference signal based on the desired press speed for each of the large number of drive units (460-466); and
    controlling the speed of each drive shaft on the basis of the drive shaft position determined and the at least one single-position reference signal.
17. Method according to Claim 16, characterized in that this further comprises the step of correcting the at least one single-position reference signal, which is based on the drive shaft position determined of one drive unit designated from a large number of drive units (460-466).
18. Web-fed rotary press, characterized by a device according to one of Claims 1 to 11.

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