DE102004048151A1 - Method for optimizing drive controllers on sheet-fed printing machines comprises determining control parameters depending on the printing machine configuration and the movement and oscillation behavior of the printing machine - Google Patents

Abstract

Method for optimizing drive controllers on sheet-fed printing machines comprises determining control parameters depending on the printing machine configuration and the movement and oscillation behavior of the printing machine. Preferred Features: Individual drives (M, R) of rotation bodies are assigned to the drive controllers and the control parameters are determined and pre-adjusted depending on the printing machine configuration and the movement and oscillation behavior at the site of each drive.

Description

The The invention relates to a method for optimizing drive controllers on sheet-fed rotary printing machines.

One The controller has the task of a preset setpoint deviant motion irregularities to compensate in the rotational movement of the rotational body driven by a drive motor. These deviations can be of different origin and, accordingly, in theirs Distinguish characteristic. The characteristic of the motion irregularities is determined by the design of the press and by the pressure conditions, by the printer through its settings on the press for processing a print job are created, given (print job related Configuration of the printing press). At different pressure conditions Different motion nonuniformities are the cause of the largest irregularities in print.

modern Sheetfed rotary printing presses have, for example, a variety of printing, varnishing and drying plants and reach due to the Series construction a considerable length. she are driven by at least one main drive motor via a continuous drive wheel train, the rotational movements of the ink and sheet-guiding cylinders, drums and mechanically synchronized rollers.

For the achievement a high print quality the positional accuracy of the applied in the individual printing units color separations or partial printing images on the printed sheet a key criterion. The printed images must to achieve a high level of detail with the least possible relative positional deviations printed on each other become.

The Positional accuracy is determined by the registration difference between the partial print images, printed in the individual printing units on the sheet be characterized. Register differences arise through accidental and / or systematic deviations in the synchronicity of the rotational movements of the Printing plate or plate, blanket or impression cylinder in the printing units, the relative displacements of the partial print images on the sheet to lead.

Characteristic are thereby systematic passport differences as a result of the change the speed of the printing press. An acceleration means for example a higher one Torque load in the drive wheel train. this leads to due to the elasticity the loaded gears to a rotation of the cylinder or drums to each other, which is so states that the print start line with each successive printing increasingly from the gripper edge moves away (the deviation of the print start line the print images of the zero position is the registration difference). This Effect is called "register spreader". With Reaching the higher speed the torque load of the drive wheel train decreases again and the register spread amount decreases is reduced. After a subsequent reduction in the speed to the initial speed is the difference between the initial pressure lines not available anymore. Amount and direction of the speed changes caused registration errors are at the same print marginal conditions (print order data) reproducible.

In more recently, printing presses are equipped with single drives, wherein the separately driven cylinders, rollers or drums (rotary body) made the drive train are dissolved out. Each individual drive is controlled by a drive controller Speed regulated. The speed control is an angular position control upstream. Both control loops synchronize the rotary motion the single drive with the drive wheel to avoid Passerdifferenzen. These are the rotational movement of the drive wheel train with a rotary encoder on the drive wheel train detected, compared with the rotational angle position of the single drive and from this correction signals for formed the drive controller. With the angular position and speed control The individual drives are rotational movements and all superimposed Bewegungsungleichförmigkeiten of the drive wheel train independently as possible of its cause delay be followed by the individual drives.

At Sheet-fed presses are in particular printing plate or plate cylinder equipped with individual drives. The single-driven printing form cylinder assigned drive controller has here together with the assigned Drehwinkellage- and speed control task, the current relative Angular position of the plate cylinder relative to the blanket cylinder (circumferential register) to keep constant at all times to the partial print image of Printing forme cylinder in the correct angle of rotation desired position on the blanket cylinder and then transfer to the bow. For circumferential register correction against the blanket cylinder is the speed setpoint for the drive controller of the plate cylinder a correction signal for acceleration or braking of the plate cylinder superimposed. The short-term Pre- or lagging the rotational movement of the plate cylinder leads to a relative rotation of the plate cylinder relative to the adjacent blanket cylinder reaches the rotational angle target position is.

In the DE 197 23 043 A1 is a method and apparatus for register-containing synchronization of successive rubber cylinders of a Rollenrotationsdruckma described machine in which the correction angle is applied as a disturbance to compensate for the caused by speed change register deviation between the upstream and downstream rubber cylinders on the reference variable of the drive controller of the downstream rubber cylinder. The proportion of aufzuschaltenden disturbance is determined from a previously determined register deviation-speed characteristic field. The register correction curves are stored for different machine types, paper grades and machine configurations in the machine control and can be called up when the job is changed. In addition, cylinder-specific control parameters are changed as a function of the printing speed, because the control dynamics of the controlled system change as a result of the dependence of the web transit time between the upstream and downstream rubber cylinders of the web speed.

In the DE 44 34 843 A1 a method for compensating for registration differences is described in which the relationship between the drive current of the main drive and torsion of the drive wheel train is used. The method takes account of predictable, systematic pressure-speed-dependent register differences.

From the DE 103 12 379 A1 is a following axis control for synchronizing master-slave drive combinations known. Operating values of the master drive (angular position, speed, acceleration and system time) are transmitted for tracking to one or more slave drives via a bus connection. The operating values are individually adapted to each slave drive with the aid of synchronization functions and change functions, so that speed and angle synchronicity between master and slave drives should exist at all times. The synchronization and modification functions can be stored in each slave drive. The slave drives are not synchronized with the respective adjacent bodies of revolution, but tracks the movements of a main drive, so that are not taken into account by the movement of the master drive deviating motion fluctuations on the slave drive.

The DE 41 20 726 A1 shows a DC main drive for printing presses, the speed control device has a switchable control characteristic to adapt the drive behavior of the main drive to two different operating variants (printing operation, Einrichtbetrieb).

adversely at these solutions is that these are control concepts, consider only systematic predictable immobility of motion and Print job dependent changes in the dynamic behavior of the printing press only insufficient attention.

The previously known control concepts of individual drives are for the avoidance non-systematic register differences not suitable.

Of the Invention is therefore based on the object, starting from the above Disadvantage the dynamic behavior of the printing press and its dependence Pressure-related boundary conditions in the drive control to take into account. According to the invention Task by a method having the features of the first claim solved.

The inventive method has the advantage that the dynamic behavior of the printing press not as a printing unit and print order independent constant size in the Regulation is included, but that the locally differentiated Movement and vibration behavior of the driven printing machine assemblies and single rotation body dependent on considering the pressure conditions so that the choice of control parameters for the existing drive controller no longer flat rate at the most unfavorable printing unit configuration, i.e. on the printing unit with the highest Vibration tendency, must be aligned, but the control parameters each individual drive controller individually to the print job to be processed and the printing unit or the unit in which the single drive is, are tunable.

The inventive method shall be on a sheet-fed rotary press with single drives closer to the plate cylinders be explained.

To shows

1 a schematic representation of a section with two printing units from a sheetfed rotary printing machine in a row construction

Sheet-fed rotary printing presses usually consist of several units in Row construction, one feeder, several printing units and a display. Each printing unit has function groups which are operated with print job-specific settings: a sheet-guiding impression cylinder DZ1, DZ2, a partial image on the sheet transferring blanket cylinder GZ1, GZ2, a plate with a plate with the partial image on its outer surface bearing plate cylinder PZ1, PZ2 and one color and dampening unit FaW1, FaW2, FeW1, FeW2 with several rollers for coloring the printing plate. With the exception of the plate cylinder PZ and the ink fountain rollers FaW all rotational body in the printing unit are driven by a drive wheel train ARZ connecting the aggregates of the printing press, which is assigned at least one main drive motor HM. Color and dampening rollers FaW, FeW, plate, blanket and impression cylinders PZ, GZ, DZ are in frictional surface contact.

For one simultaneous plate changes are made by the plate cylinders PZ1, PZ2 each individual drives M1, R1, M2, R2, which in the printing operation, the rotational movements the neighboring blanket cylinder GZ1, GZ2 synchronously, to Passerdifferenzen by relative movements between the partial print image transmitted cylinder surfaces to avoid.

Each Single drive motor M1, M2 is a drive controller R1, R2 with Cascaded Drehwinkellage- and speed control assigned. The Cascade controls work with rotary encoders W1, W2 on the drive wheel train ARZ, preferably on the blanket cylinders GZ1, GZ2, together, of which they receive the rotation angle command signals. The rotation angle and The speed reference signals formed therefrom are derived from the cascade control with the of the rotary encoders W1, W2 of the single drive motors M1, M2 derived rotational angle and actual speed signals compared and from this speed correction signals for the drive controller R1, R2 educated. The angular position and speed control can be used in the controller R be integrated or a separate device within the aggregate control form. The control characteristic of the angular position and speed control shows in a known manner proportional, integral and differential control shares (PID controller) with programmable control parameters. The drive controllers R1, R2 are storage means S1, S2 for storing regulator preset data assigned.

For the mode of action of the method according to the invention:
The drive controller R of the single drive M, R has the task occurring in the drive wheel ARZ motion irregularities of different origin, which affect the rotational movement of the respective blanket cylinder GZ, with which the plate cylinder single drive motor M is synchronized, as quickly as possible on the plate cylinder PZ retrace, so that the Synchronicity of the rotational movements of both rotating body PZ, GZ is maintained.

The Control parameters for the synchronization of the individual drives M, R on the plate cylinders PZ are now determined according to the invention and for subsequent ones print jobs Preset that the corrective movements of the plate cylinder PZ in Winkelgeschwin speed, acceleration and phase angle so optimal carried out that they on the one hand Umfangsregisterabweichungen the plate cylinder PZ possible Completely on the other hand do not initiate new vibrations, the above the surface contact transferred to the blanket cylinder GZ and the drive wheel train ARZ become.

With an optimal control characteristic will undesirable torque effects and vibrations within the printing press units up to Resonance increases, which is undesirable express high register differences, reliably avoided.

in the Contrary to the known single drive regulations considered the proposed procedure for the parameterization of the drive controller R there are differences in the unit or printing unit specific Dynamics of the control circuits, in turn, from the configuration of individual aggregates / printing units and ultimately the construction of the printing press and depend on the specific print job.

The Control circuits for the synchronization of the plate cylinders PZ each include the Single drive motor M with a rotary encoder for position control, the thus driven plate cylinder PZ, the in rolling contact standing blanket cylinder GZ and arranged on the blanket cylinder GZ Rotary encoder W for the rotation angle setpoint.

The to be traced with the drive controller R and the single drive motor M. Bewegungsungleichförmigkeiten of the blanket cylinder GZ are printed or unit-specific Rotation vibrations caused in the drive wheel ARZ.

The Vibration behavior of the drive wheel train ARZ in and between The individual printing units is supported by a variety of promotional or steaming Factors influenced.

As a result of the growing number of print, Paint and drying plants in modern printing machines and the resulting increasing length of the drive wheel trains also increases their elasticity. In connection with the increase of the printing speeds thereby increases the tendency of the printing machine to vibrate and thus the influence of rotational oscillations in the drive wheel train ARZ and thus caused fluctuations in the rotational angle relative positions between the rotational bodies within the printing press, which manifest themselves in locally different, non-systematic register differences.

rotational vibration in the drive wheel train are excited by channel joints of cylinders with channels for clamping elements or gripper, clock-bound oscillating movements of sheet transport elements in sheetfed, sheet display or sheet turning device, the from the drive wheel train be driven with.

vibration sources are, for example, in a channel passage suddenly sloping and again increasing positioning and bearing forces, oscillating movements a vibration system or a stop drum at the sheet feeder, sheet brakes or Nachgreiferbewegungen in the sheet delivery or braking and accelerate the bow in the one-drum turn. The vibration intensity is i.a. from the aggregate construction, the printing speed, the sheet material and the sheet format determined largely by the printing press and the print job are set. The degree of influence of the vibration exciters on the vibration behavior at the location of the single drive is from its distance to the vibration sources dependent and in the single drive related Determination of the control parameters to be considered.

Vibration-damping effect frictional movements such as the roller friction in the inking and dampening FaW, FeW, Delta Drive Modes for Ink and Dampening Systems FaW, FeW, the rolling friction between plate cylinder PZ and blanket cylinder GZ with set pressure pressure or different tension in the drive wheel train ARZ by braking torques of a second main drive or a decentralized one Drive.

The damping accordingly, the viscosity and film thickness of the transferred ink and dampening solution, the connection of delta drives, the Features of the lifts or the strength the pressure pressure influences. These printing conditions vary between the printing units and are also on the concrete Print job coupled.

The job-specific settings to that of the drive wheel train ARZ driven bodies of revolution specify the local print engine configurations required for order processing and thus determine the local tendency to oscillate at the location of the respective Single drive M, R in the drive wheel train ARZ.

The Position of the respective individual drive M, R within the printing press determined relative to the vibration sources (system, display, turning device) the local vibration intensities in the rotation angle setpoint for The control circuit of the single drive M, R. Thus, first the amount and frequency of local setpoint oscillations in the optimization of the control dynamics for the Single drive control considered become.

The Dynamics of the single-drive controlled system continue to depend on pressure and printing unit-specific settings or adaptation measures on the rotating bodies depending on the individual units, in particular the vibration damping properties of Affect print engine configurations.

The Control characteristic, resulting from the by the control parameters quantified proportions of proportional, integral and differential control results, therefore inven tion according to the printing unit specific Tuned control line dynamics. Only in this way can deviations (Register differences) as fast as possible be corrected without at the same time instabilities of the control loop and thus new disorders to create. Determining the appropriate control parameters itself according to the known stability criteria of control loops and is based on mathematical torque, vibration and control loop models or empirically in the printing operation after evaluation the local Register differences.

at the optimization of the drive control characteristic are in addition to the dynamic properties of the single drive motor M and the printing unit / unit in a further step, the control dynamics limiting factors, like the elasticity the coupling elements between the single drive motor M and plate cylinder PZ considered. coupling elements can Clutches, shafts, gears.

Farther are the self-driven plate cylinder PZ itself caused vibrations through channel beats and their repercussion on the rotational movement of standing in rolling contact blanket cylinder GZ to take into account in the control parameter optimization.

The above-described complexity of Relationships make high demands on a calculation of the control parameters on the basis of mechanical replacement models of the control loops, so that an empirical determination of the optimal control parameters for the individual drive controller R in the context of preliminary tests, test runs or proofs under the practical constraints of specific print jobs is preferred.

It is advantageous, the control parameters for selected, characteristic of the particular printing press Printing conditions for the majority of expected print jobs must be created, and for printing unit configurations defined above in test runs to optimize empirically. These are the correlations between the measured register differences in the printing units and the varied Control parameters of the individual drives R, M drive-related to determine. The determined control parameter sets are shared with the print job data and selected print engine configurations in storage means S for preset data stored. Suitable storage means are RAM storage areas within the drive controller R, the aggregate control, the central machine control MS or the higher-level print management system. The stored control parameter sets can be used continuously during the processing of print jobs for new ones Adjusted printing conditions or other printing unit configurations or optimized.

It It has been shown that for the individual printing units determined Preset records primarily in relation on the rule gain, i.e. the proportional control component, differentiate. Therefore, appears it is expedient to Focus of optimization on the control gain. Accordingly could simplifying the drive controller R in the printing units of a printing press with approximate constant differential and integral control parameters are operated and primarily the control gain is druckwerkbzw. To optimize unit specific, resulting a reduction of the effort for the empirical determination the optimal control parameter results.

Should now a new print job will be processed, which will be available Print job and press configuration data to the machine control MS handed over and compared with stored order related records. According to specifiable Selection criteria is then selected a suitable stored record and The assigned control parameters are drive-related to the drive controllers R handed over. Should No suitable record is available from records for similar ones Interpolate print job data.

global Selection criterion is the similarity of the print job-related enabled aggregates and press settings, i.e. the press configuration. This criterion may be specific to presses be limited to vibration critical aggregates. The selection can done by the printer, but is also on the machine control MS transferable. In this case, the print job-specific settings, the printer at the printing machine device to the individual Aggregates of the printing machine has been made by the machine control MS and compared with stored presetting data sets. According to the predefinable and programmed selection functions becomes a suitable presetting data record from the machine control MS selects and the individual control parameter sets based on individual drives the drive controller R transmits.

For the processing In the current print job, pre-optimized control parameter data sets are added Use it by adapting it to the pressure conditions in particular allow, with higher Control gain repeatable and with fewer register differences compared to non-optimized drive controls M, R, to avoid Loop instabilities at the worst Control loop constellation must be aligned to print.

Consequently can significantly improve the printing result by printing and printing-related optimization of the control parameters are achieved, being taken by consideration the printing conditions in a printing unit also the printing accuracy is improved in an adjacent printing unit due to the reduction the over the surface contact the individually driven rotary body PZ transmitted to the drive wheel train ARZ Loop oscillations.

The proposed method is also for the control parameter optimization suitable for drive controllers R, the drive motors for several Rotating body, i.e. Cylinder groups, printing press units or main drives HM for continuous drive wheel arches ARZ, assigned.

By a print job-related optimization of the control gain for a press main drive, for example, speed corrections can be made so that the occurring acceleration or braking torques are limited by the choice of suitable control gains for the main drive HM to maximum values at which unacceptably high register spreader no longer occurs. The torques that are transmitted to the individual printing units during a speed correction and are printer specific passer differences be are dependent on the particular print job-related press configurations.

For example elevated the delta mode of operation of a printer connected by the printer driven dampening unit FeW (dampening roller rotates with lower surface speed as the plate cylinder PZ) the load torque of a printing unit and thus the drive wheel ARZ transferred to the printing unit Torque, so that the elastic deformation of the drive wheel train ARZ increases and accordingly higher register differences occur. In this case, reduce the control gain for the main drive HM, as soon as the delta drive for one or more dampening unit (s) FeW is switched on.

ARZ

drive wheel

DZ, DZ1, DZ2

Impression cylinder

FaW, FaW1, FaW2

inking

FeW, FeW1, FeW2

dampening

GZ, GZ1, GZ2

Blanket cylinder

HM

Main drive motor

M, M1, M2

Single drive motor

PZ, PZ1, PZ2

plate cylinder

R R1, R2

drive controller

S, S1, S2

storage means for presetting data

MS

machine control

W W1, W2

Rotary encoder

UT

Transfer drum

Claims (8)

Method for optimizing drive controllers (R) on sheet-fed rotary printing presses, with control parameters depending on from the print job related press configuration and the characterized by it Motion and vibration behavior of the printing press drive related be determined and preset. The method of claim 1, wherein the drive controllers (R) individual drives (M, R) are assigned by bodies of revolution and the Control parameters individual drive-related as a function of the job-related Printing press configuration and the characterized motion and vibration behavior at the location of each individual drive (M, R) determined and preset become. The method of claim 2, wherein - the individual drives (M, R) rotation body driving with neighboring, from a drive wheel train (ARZ) driven bodies of revolution are synchronized, - the Control parameters of the drive controllers (R) for the individual drives (M, R) considering the motion and vibration behavior of the individually driven body of revolution and the drive wheel train (ARZ) at the location of the single drive (M, R) individually for each Drive controller (R) can be determined - the individually determined Control parameters as print job-related presetting data sets in storage means (S) for Preset data associated with the drive controllers (R) are stored become, - in which before the beginning of each print job to be executed the current print job data with saved job related Voreinstelldatensätzen and a suitable job-related presetting data set for the Drive controller (R) selected and the drive controllers (R) are programmed with it. The method of claim 1, 2 or 3, wherein the drive related Preset data for the drive controllers (R) from mathematical torque and vibration models calculated or in test runs, Proofing or during the processing of print jobs be determined empirically. The method of claim 1, 2 or 3, wherein in new orders the Print job data from a machine control (MS) automatically after predetermined criteria evaluated, a correlated stored Print job-related presetting data set for the drive controller (R) selected and adapted and the drive controllers (R) are programmed with it. Method according to one of claims 1 to 5, wherein the drive-related Control parameters at least the position of the driven rotating body relative to vibration sources, color and dampening modes, surface pressures between the bodies of revolution, Features of the lifts on the bodies of revolution, the color viscosity and / or the tension and stiffness of the drive wheel train (ARZ) at the location of the drive consider. Method according to one of claims 1 to 5, characterized the default data contains the print job-related control gains. Method according to claim 3, wherein the individual drives (M, R) Druckform- or plate cylinders (PZ) are assigned, the synchronized with the rotational movement of blanket cylinders (GZ).