EP2050699A2 - Method for calculating the diameter of a winding of web material on a roll and winding control system - Google Patents

Abstract

The method involves calculating a diameter (D) of a web material winding (112) in a winding control system (150). Winding speed is changed when a swivel arm (110) supporting a roll (111) is swiveled around a swiveling axis (A) of the arm during a winding motion. A correction value for correcting change of the winding speed is incorporated into the calculation of the diameter of the web material winding. The correction value is determined within the winding control system, and utilized for pre-controlling the winding speed of the roll. Independent claims are also included for the following: (1) a winding control system comprising a control unit for controlling a winding movement of a roll (2) a computer program with a program code for performing a method for calculating diameter of a web material winding on a roll (3) computer program product with a program code for performing a method for calculating diameter of a web material winding on a roll.

Description

The present invention relates to a method of calculating the diameter of a web winding on a roll and to a winding control system. Furthermore, the present invention relates to a computer program and a computer program product.

Although reference will be made hereafter mainly to printing machines and their roll changers and controls, the invention is not limited thereto, but rather applicable to all types of web-processing machines in which the diameter of a web winding is to be determined. However, the invention is particularly in printing presses such as newspaper printing machines, commercial printing machines, gravure printing machines packaging printing machines or security printing machines and processing machines such as bag machines, envelope machines or packaging machines can be used. The web can be made of paper, cloth, cardboard, plastic, metal, rubber, in foil form, etc.

State of the art

The present invention can be used in particular for determining the diameter of web windings on roll carriers or roll changers. A reel changer usually has at least two pivotable about a pivot axis pivot arms, each carrying a roll for winding or unwinding of a web. Usually, the pivot arms are freely pivotable by means of an electric drive about the pivot axis to allow a flying reel change at full production speed. During processing, one of the rollers is in contact with the machine via the web, the web being either taken out of the machine's outfeed and wound onto the reel or unwound from the reel and fed to the machine. The roll is also driven by a drive, usually a center drive, peripheral drive or the like.

The diameter of the wound web on the roll constantly changes during the winding process and is determined by a winding control, for example by means of the speed ratio between the winding speed and the web transport speed. The web transport speed is taken at a reference axis, in particular a web transport axis, wherein the reference axis defines a reference to the transport speed of the web. The reference axis can do this also be a simulated or emulated axis (so-called virtual axis). The diameter of the winding is proportional to the ratio of the two speeds mentioned. The winding control controls the winding process and the role change process. During the reel change operation, the swivel arm with the winding currently in the production process is swung away from the web-processing machine and the swivel arm with the replacement reel is pivoted to the web-processing machine. However, the pivoting movement of the pivot arm influences the winding or unwinding speed, ie the rotational speed of the roller, since the roller has to compensate for an extension or shortening of the length of the web through a unwinding or winding movement. This compensation movement leads to an effective winding or unwinding speed (rotational speed), which is no longer proportional to the diameter of the winding. The determination of the diameter is therefore faulty during the pivoting movement, wherein the error is greater, the smaller the web transporting speed, the greater the pivoting speed or the longer the pivoting arm.

Especially with small winding diameters, the pivoting movement leads to a large miscalculation. This is particularly problematic in unwinding, since here the roll change usually takes place at very small diameters. The relatively large error in the diameter calculation resulting from the above reasons is usually countered by a sufficient reserve of the remaining material on the roll. The material is thus not optimally utilized.

To avoid the mentioned problems, it is known to stop the diameter calculation during a pivoting movement. Accordingly, no current diameter value is available for the time of the pivoting movement, which is disadvantageous in particular with a small winding diameter.

Likewise, it is known to perform the specification of a correction speed by a control superimposed on the winding control or superposed entity. This is associated with several problems, since numerous variables or parameters that are necessary to determine the correction speed, must be transmitted to the higher-level control or must be determined by this.

It is therefore an object of the present invention to improve the calculation of the diameter during a pivoting movement.

This object is achieved by a method for calculating the diameter of a web winding on a roll, a winding control system, a computer program and a computer program product having the features of the independent patent claims. Advantageous developments are the subject of the dependent claims and the following description.

According to the invention, the diameter of a web winding on a roll is calculated. The roller is carried by a pivotable about a pivot axis pivoting arm, wherein the roller rotates at a variable winding speed, wherein the web is unwound from the roll and fed to a webbing machine or a web machine removed and wound up on the roll. The roller and the swivel arm are in particular part of a reel changer with center winder, peripheral winder or the like. The winding speed is adjusted as a function of the web transport speed to ensure the synchronization of the winding movement with the web movement. The calculation of the diameter of the fabric winding on the roll is performed in a winding control system, wherein a change in the winding speed occurs when the roller bearing the pivot arm is pivoted during the winding movement about its pivot axis. A correction value for correcting the change in the winding speed is included in the calculation of the diameter of the web winding, wherein the correction value is determined within the winding control system.

The invention further relates to a corresponding winding control system, which is designed to determine the diameter and the correction value and to take into account accordingly in the calculation of the diameter.

Advantages of the invention

According to the invention, a correction value is determined, which is used in particular for correcting the speed or angular position ratio of winding axis and reference axis in order to ensure a correct diameter determination during the pivoting movement. The correction value is used as feedforward control for the winding control system. According to the invention, the correction value is determined and predetermined by the same winding control system, which also includes the diameter calculation performs and preferably controls the movement of the pivot axis. The determination of the diameter of the winding is improved, especially at low machine speeds and high slewing speed. An interruption of the diameter determination during the pivoting operation can advantageously be omitted.

In particular, the correction is feasible such that the correction value corresponds to the corresponding size of the winding axis, i. Rotational speed or angular position, added (added or subtracted). For the diameter calculation, the quotient of the corrected winding axis size and the corresponding reference axis size is then used. It is understood that a correction of the reference axis size by means of the correction value is also possible.

When determining the correction speed, variables are necessary which are typically present in the winding control system internally or can easily be determined. Another advantage of the combination of swivel control, winding control, diameter determination and correction value determination is the associated saving of data transmission to higher-level instances and the simpler configuration of these instances.

It is particularly useful if the correction value is used to precontrol the winding speed of the coil carrying the winding. During a pivoting operation, in principle, the roller drive has to perform a rotational movement in order to compensate for the lengthening or shortening of the material web. This rotation is now also called Pre-control of the movement of the roller drive on the position or the target speed of the roller drive switched. This ensures that - depending on the configuration of the reel changer - a possibly existing dancer dwells in the rest position or does not perform any movement or that in the absence of a dancer of the web tension controller must perform any adjustment movement. This eliminates the disadvantage of the prior art that the dancer position does not remain constant during a pivoting movement and is only compensated by an occurring control deviation in the dancer position controller.

It is advantageous if a correction speed ω _{K is determined} as a correction value and the calculation of the diameter D of the product web winding is carried out on the basis of the winding speed ω and the web transport speed. The correction speed ω _K provides a positive or negative correction value for the winding speed ω or the web transport speed. The web transport speed at a time t ₀ can be determined, for example, as the product r _R · ω _R (t ₀ ) of the radius r _R and the rotational speed ω _R (t ₀ ) of a reference axis R, for example a web transport axis of the web feed. The uncorrected diameter D (t ₀ ) of the winding on the roll at the time t ₀ is thus determined in a simple manner to D (t ₀ ) = 2r _R · ω _R (t ₀ ) / ω (t ₀ ) and taking into account the correction speed in particular to D (t ₀ ) = 2r _R · ω _R (t ₀ ) / (ω (t ₀ ) + ω _k (t ₀ )).

Also advantageously, a correction angle position Φ _{K is determined} as the correction value and the calculation of the diameter D of the web winding on the basis of an angular position Φ the role and an angular position Φ _R a web transport axis or reference axis performed. The correction angle position Φ _K provides a positive or negative. Correction value for the angular position Φ of the roller or the angular position Φ _{R of} the reference axis. The calculation of the diameter can for example always take place when the angular position Φ of the roller (or the angular position Φ _{R of} the reference axis) has reached a predetermined value, for example 360 °. At this point in time T, the angular position Φ _R (T) of the roller is determined. The uncorrected diameter D (T) of the winding on the roll at the time T is thus determined in a simple manner as D (T) = 2r _R ·Φ _R (T) / Φ and taking into account the correction angle position, in particular to D (T) = 2r _{R R} (T) / (Φ + Φ _K ). The difference between the use of angular positions and the use of speeds is that when using speeds for a stationary machine, a division of substantially 0/0 would be performed, whereas when using angular positions only a diameter calculation is performed, if one of the considered angular positions exceeds certain limits. This prevents a division of 0/0.

It is expedient if the correction value is determined as a function of a length and a pivoting speed of the pivoting arm within the winding control system. The correction speed depends, in particular, on (constant) geometry data, ie the length of the swing arm, the distance of the pivot axis from the machine axis receiving / dispensing the material web, and current process data (current actual values) such as the current angular position of the swivel arm, current diameter of the winding, current swivel speed. A particular advantage of the invention is that said current process data are already available within the winding control system, which allows the calculation of the correction value without complex data transmission.

The correction value can be calculated as a function of the rotational speed of the swivel arm, position-dependent swivel arm characteristic or interpolation point characteristic and / or sum of radius of the winding and swivel arm length. Advantageously, all the factors mentioned are used. In the position-dependent swing arm characteristic go the geometric conditions that arise depending on the position of the swing arm, a.

In a preferred embodiment, the interpolation point characteristic includes one revolution of the swivel arm, ie 0 ° to 360 °. However, it is appropriate in certain embodiments, to deposit only a part of the total revolution, since in a reel changer usually the active role is pivoted only in a sub-range of the entire revolution, since the role outside of this range is not active, ie no winding is performed. The interpolation point characteristic can be determined by means of a measuring run, wherein the corresponding table value is determined at several angular positions of the swivel arm on the basis of the winding speed of the roller and the swivel speed. Likewise, a determination based on the known geometric configuration is possible. It is advisable to reduce the interpolation point characteristic to a few interpolation points, between which interpolation is appropriate.

Points outside the interpolation point characteristic are extrapolated in a suitable way.

In addition to the use of a support point characteristic, the determination of a geometry-dependent, calculated factor is proposed. This can be calculated based on the known geometric design of the roll changer and the web machine, in particular, a calculation can be carried out within the winding control system. The geometric parameters can be introduced into the winding control system during commissioning or during production, for example. Alternatively, it is conceivable to use an approximation formula. For example, in unwinding operations, the current diameter can be neglected when using the Schwenkarmlänge.

The interpolation point characteristic and the calculated factor can be stored within the winding control system, calculated there or specified by a higher-level instance.

The invention additionally relates to a computer program with program code means in order to carry out all steps for calculating the diameter and the correction value according to a method according to the invention, when the computer program is executed on a computer or a corresponding computing unit, in particular in a winding control system according to the invention.

The inventively provided computer program product with program code means which are stored on a computer-readable data carrier, is for performing all steps designed for calculating the diameter and the correction value according to a method according to the invention when the computer program is executed on a computer or a corresponding computing unit, in particular in a winding control system according to the invention. Suitable data carriers are, in particular, floppy disks, hard disks, flash memories, EEPROMs, CD-ROMs, DVDs, and the like. It is also possible to download a program via computer networks (Internet, intranet, etc.).

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained not only in the combination specified; but also in other combinations or alone, without departing from the scope of the present invention.

The invention is illustrated schematically by means of embodiments in the drawing and will be described in detail below with reference to the drawing.

figure description

FIG. 1

shows a schematic representation of a roll changer for use with a preferred embodiment of the invention and an example of a winding control system according to the invention; and

FIG. 2

shows an embodiment of a support point characteristic.

In FIG. 1 a reel changer for a web machine is shown schematically and designated 100 in total. The reel changer has a base 101, to which a first, pivotable about a pivot axis A pivot arm 110 and a second pivotable about the pivot axis A pivot arm 120 are attached. The first pivot arm 110 has, at its end facing away from the stator, a rotatable, drivable roller 111, which carries a winding 112 of a material web 113. The reel changer is controlled by a preferred embodiment of a winding control system 150 according to the invention, the means for controlling a winding movement of the rollers 111 and 121, means for controlling the pivotal movement of the pivot arms 110 and 120, means for calculating the diameter D of the web windings 112 and 122 on the rollers 111 and 121 and means for determining a correction value for correcting the change in the winding speed in response to a pivoting movement of the rollers 111, 121 carrying the pivot arms 110 and 120, respectively.

The web 113 is unwound in the illustrated embodiment of the roller 111 and fed via a first guide roller 130, a movable dancer roller 131 and a second guide pulley 132 to a feed train or Infeed a web machine. The up and down movable, for example, be acted upon by compressed air dancer roller 131 serves to control the drive speed of the roller 111th

In the depicted dancer winder, the web tension is applied via a force impressed in the dancer 131; a superimposed dancer position controller ensures that the dancer 131 remains within its mechanical limits. The measured variable of the dancer position controller is the position of the dancer, the manipulated variable of the dancer position controller is an additive position / speed of the roller drive. In addition, there are dancerless systems in which the web tension is impressed on the torque of the roller drive. Here a superimposed force control ensures the regulation of the web tension. Measurand here is the web tension, e.g. by means of a load cell, the manipulated variable is the torque or a torque limit of the roller drive.

The length of the first pivot arm 110 from the pivot axis A to the center of the roller 111 is denoted by L. The actual diameter of the winding 112 is denoted by D. In the position shown, the diameter D of the winding 112 corresponds to the ratio of diameter times the rotational speed of the guide roller 130 to the winding speed of the roller 111. The length of the material web 113 between the winding 112 and the first guide roller 130 is designated by 1. For the representation of the geometric conditions is in FIG. 1 deposited a coordinate system whose origin is in the pivot axis A. The angle of the pivot arm 110 to the x-axis of the coordinate system is denoted by φ.

The second pivot arm 120 corresponds in its mechanical configuration to the first pivot arm 110 and carries on a roller 121, a winding 122, which is provided for a flying role change. To carry out the flying Reel change the first pivot arm 110 and the second pivot arm 120 are pivoted counterclockwise until the second winding 122 engages the web 113 in operative connection, whereupon the web 113 separated from the winding 112 and the winding by suitable, not shown, cutting devices 122 is connected.

During the pivoting movement just described, the length of the material web 113 denoted by 1 extends from the winding 112 to the first deflection roller 130. This change in length must be compensated by an increased winding speed or rotation speed of the roller 111 in order to keep the dancer roller in its position. As a result, the above-described ratio of the transport speed of the web to the rotational speed or winding speed of the roller 111 is no longer proportional to the actual diameter D of the winding 112. To correct the deviation, a correction value in the diameter calculation is used, which is the change caused by the pivoting movement the winding speed taken into account in the diameter calculation. As described above, this consideration can be done, for example, by taking into account the rotational speed or by taking into account the angular position.

In FIG. 2 is a diagram 200 shows an embodiment of a support point characteristic 201, which is based on the in FIG. 1 calculated geometric relationships was calculated. The interpolation point characteristic is one of the preferred possibilities with which a correction value for correcting the change in the winding speed can be determined. It It should be noted that instead of extracting a value from a breakpoint characteristic, the correction value may also be calculated directly in the winding control system.

In the diagram 200, a change Δl of length 1 on a y-axis 203 is plotted against the swivel angle φ on an x-axis 202. The representation corresponds to a rotation of the pivot arm 110 in the counterclockwise direction about the pivot axis A. Each support corresponds to the change in length of length 1 at a pivoting by 1 °. As the basic geometry, a swing arm length L = 2.0 m, an actual diameter D = 0.5 m, a (x / y) position of the first deflection roller 130 of (2.0 / 2.0) are used. With these values, for example, the length 1 at a pivoting of 120 ° to 121 ° changes by Δl = 0.0346 m, which is the base (120 ° / 0.0346) removable and corresponds to an extension of the web by 0.0346 m , Negative values correspond to a shortening of the web. The change in the length 1 caused by the displacement of the point of tangency on the winding 112 is neglected in this consideration. It is understood that with a more accurate correction, this shift can also be taken into account. Similarly, a constant diameter is used in the illustrated characteristic curve. This is always appropriate when the diameter of the winding is small compared to the Schwenkarmlänge, thus in particular in the described Abwickelvorgängen.

For determining the correction value in a panning operation, all values between the start angle of the panning operation and the end angle of the panning process are summarized. From this summary, the entire results Length change of the web between the roller 111 and the first guide roller 130. The values taken from the characteristic or preferably calculated online are now used to correct the diameter calculation. In the correction by means of a correction angle position φ _k as the correction value, the determined length change Δl is converted over the actual diameter of the winding into the correction angle position φ _k . This proportion is then added to the actually determined angular position, as has already been described above. According to a further preferred embodiment of the invention, the correction values are used for the precontrol of the drive of the roller 111 in order to avoid a movement of the dancer roller 131.

It is understood that in the illustrated figures, only exemplary embodiments of the invention is shown. In addition, any other embodiment is conceivable without departing from the scope of this invention.

reference numeral

100

reelstands

101

stand

110, 120

swivel arm

111, 121

role

112, 122

winding

113

web

130, 132

idler pulley

131

dancer roll

A

swivel axis

200

diagram

201

Base curve

202

x-axis [°]

203

y-axis [Δl]

Claims (13)

Method for calculating the diameter (D) of a fabric winding (112, 122) on a roll (111, 121),
wherein the roller (111, 121) is supported by a pivoting arm (110, 120) pivotable about a pivot axis (A),
wherein the roll (111, 121) rotates at a variable winding speed, wherein the web (113) is unwound from the roll (111, 121) and fed to a web machine or taken from a web machine and wound onto the roll (111, 121),
wherein the winding speed is adjusted as a function of the web transport speed,
wherein the calculation of the diameter (D) of the web winding (112, 122) is performed in a winding control system (150),
wherein a change in the winding speed occurs when the pivot arm (110, 120) carrying the roller (111, 121) is pivoted about its pivot axis (A) during the winding movement,
wherein a correction value for correcting the change in the winding speed is included in the calculation of the diameter (D) of the web winding (112, 122),
wherein the correction value is determined within the winding control system (150). Method according to claim 1, wherein the correction value is used for the precontrol of the winding speed of the roller (111, 121). A method according to claim 1 or 2, wherein a correction speed is determined as a correction value and the calculation of the diameter (D) of the web winding (112, 122) is performed on the basis of the winding speed and the web transport speed. The method of claim 1 or 2, wherein a correction angle position is determined as a correction value and the calculation of the diameter (D) of the web winding (112, 122) based on an angular position of the roller (111, 121) and an angular position of a reference axis is performed. Method according to one of the preceding claims, wherein the correction value in dependence on a length (L) and a pivoting speed of the pivot arm (110, 120) is determined. Method according to claim 5, wherein the correction value is determined as a function of the length (L) of the swivel arm (110, 120) and the actual diameter (D). Method according to one of the preceding claims, wherein the correction value is determined as a function of a geometry-dependent, stored support point characteristic (201). Method according to one of the preceding claims, wherein the correction value is determined as a function of a geometry-dependent, calculated factor. Method according to claim 7, wherein the stored interpolation point characteristic (201) is determined with the aid of an explicit measuring travel on the basis of measuring points or calculated from the knowledge of the geometric arrangement, wherein interpolation between the interpolation points is extrapolated outside the interpolation points. The method of claim 8, wherein the geometry-dependent calculated factor is determined analytically. Winding control system with
Means for controlling a winding movement of a roller (111, 121), wherein the roller (111, 121) is rotatable at a variable winding speed, wherein a web (113) of the roll (111, 121) unwound and a webbing machine or a webbing machine removable and on the roll (111, 121) can be wound up,
Means for controlling the pivoting movement of a pivoting arm (110, 120), the roller (111, 121) being portable by the pivoting arm (110, 120) pivotable about a pivoting axis (A),
Means for calculating the diameter (D) of the fabric winding (112, 122) on the roll (111, 121), and
Means for determining a correction value for correcting the change in the winding speed in response to a pivotal movement of the pivot arm (110, 120) supporting the roller (111, 121). Computer program with program code means for carrying out all the steps of determining the diameter (D) and the correction value of a method according to one of claims 1 to 10, when the computer program is executed on a computer or a corresponding computing unit, in particular a winding control system (150) according to claim 11 becomes. A computer program product comprising program code means stored on a computer-readable medium for carrying out all the steps of determining the diameter (D) and the correction value of a method according to any one of claims 1 to 10 when the computer program is run on a computer or a corresponding computing unit, in particular a winding control system (150) according to claim 11, is executed.

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