Method and system for detecting a traversing defect

Abstract

The invention relates to a method for detecting a traversing defect during the winding of a link (L) on a reel (1) rotated about a longitudinal axis (X), the link (L) being guided by a guide pulley (2) in a reciprocating translation with respect to the reel (1) along said longitudinal axis (X) between two reversal positions, comprising: - measuring the position of the guide pulley (2) with respect to the reel (1) along the longitudinal axis (X) over time; - measuring the position (P2) of a device regulating the speed of travel of the link on the guide pulley over time; - from said measurements, determining a difference between the position (P3) of the regulating device and a reference position (P3r) at each reversal position (Pi1, Pi2); and - based on this difference, detecting the formation of a hollow or a bump in the winding.

Description

FIELD OF THE INVENTION

[0001] The invention relates to a method and a system for detecting a cutting defect. STATE OF THE ART

[0002] There are a number of applications in which a link intended to carry a fluid or transmit energy and / or signals (e.g., electric current, optical signals, mechanical tension, fluid, etc.) must be wound onto a spool, in order to be transported, stored and / or used.

[0003] In general, it is necessary that the winding of the tie on the reel be regular, that is to say that the tie is wound on the reel in the form of one or more successive layers of turns that are joined or have a minimum of play between them. Such regular winding in fact ensures the mechanical integrity of the tie and also allows the tie to be unwound with a substantially constant tension of the tie.

[0004] For this purpose, the tie winding system is provided with a shunting system, which comprises a guide pulley arranged opposite the spool, adapted to control the location of each new turn relative to the turns already deposited on the core of the spool. When winding the tie, the spool is driven in rotation around the axis of revolution of the core, and the guide pulley is driven in alternating translation relative to the spool (or vice versa) in a direction parallel to said axis, between two inversion positions which are located in the vicinity of each of the two flanges of the spool.

[0005] However, it may happen that, due to faulty adjustment of the inversion positions of the guide pulley, too much of the link accumulates in the vicinity of a flange of the coil, resulting in a bump on the outer surface of all the turns, or, on the contrary, that the link is not wound up to the flange, causing a hollow on the outer surface of all the turns.

[0006] Indeed, the width of the coil, which corresponds to the distance between the two flanges, is not always known precisely. For example, if the coil is made of molded plastic, there may be significant dimensional variations between two similar coils.

[0007] Additionally, as the tie is wound onto the spool, the sides may move apart under the pressure of the tie, affecting the filling of the spool.

[0008] Such a defect can be visually observed by an operator and corrected by changing the dimension of the inversion positions.

[0009] However, this detection is not very accurate and may only be performed when a significant winding fault has been observed, which is not satisfactory.

[0010] Document JPH09276932 describes a winding system for winding an optical fiber onto a reel, comprising a motor equipped with a rotary encoder, a ball screw coupled to the motor and to the reel to drive the reel in translation alternately in two winding directions opposite a fixed pulley. The motor changes direction of rotation based on data from proximity sensors arranged on a support, which detect the position of the flanges of the reel. The device further comprises a sensor for detecting the position of the optical fiber, and a control device which controls the direction of rotation of the motor based on a fiber speed signal at the pulley and a winding position signal provided by the encoder. A curve is plotted representing the position of the wire at the time of a change in winding direction, detected by the detector.The presence of a hump indicates excess winding thickness at a coil flange. In response to detecting such excess thickness, the control device adjusts the winding direction reversal position. This results in a reduction of the hump at the next reversal position.

[0011] Document JPH08217333 describes a spooling system comprising a sensor for measuring the distance of the axis of the guide pulley from one of the flanges of the reel. The instant of change of spooling direction is determined on the basis of geometric considerations. The spooling direction is reversed when the distance between the wire and the flange is less than half the wire diameter.

[0012] Document JPH08217330 describes a spooling system in which the wire feed and winding speeds on the reel are controlled by means of respective encoders, so as to equalize these two speeds. Documents JP2008001451A and JP2006008310A describe other spooling systems comprising spooling defect detection systems. STATEMENT OF THE INVENTION

[0013] One aim of the invention is to design a method for detecting a cutting defect which can be implemented automatically.

[0014] Advantageously, this detection method must also be compatible with an automatic correction method for the cutting defect.

[0015] To this end, the invention proposes a method for detecting a spooling defect when winding a tie onto a reel driven in rotation around a longitudinal axis, the tie being guided by a guide pulley in alternating translation relative to the reel along said longitudinal axis between two inversion positions, according to claim 1, comprising: measuring the position of the guide pulley relative to the spool along the longitudinal axis over time, - measuring the position of a device for regulating the speed of travel of the link on the guide pulley over time, from said measurements, determining a difference between the position of the regulating device and a reference position at each inversion position, and from said difference, detecting the formation of a hollow or a bump in the winding.

[0016] According to one embodiment, the device for regulating the speed of movement of the link is a puppet comprising a pulley arranged at the end of an arm capable of pivoting around a horizontal axis against the return force of a spring, and in which the measured position is the angular position of the arm of the puppet relative to a vertical axis.

[0017] In this text, "horizontal" means a direction perpendicular to the direction of gravity, and "vertical" means the direction of gravity.

[0018] According to the invention, the measurement of the position of the regulating device is carried out in a measurement window encompassing each inversion position.

[0019] According to the invention, the minimum and maximum positions of the control device are determined in each measuring window and deviations between each respective minimum or maximum position and the reference position of the control device are calculated.

[0020] Particularly advantageously, the method comprises comparing the absolute values ​​of said deviations and determining: of the formation of a hollow in the winding if the absolute value of the deviation between the maximum position and the reference position is greater than the absolute value of the deviation between the minimum position and the reference position, of the formation of a hump in the winding if the absolute value of the deviation between the maximum position and the reference position is less than the absolute value of the deviation between the minimum position and the reference position.

[0021] From the deviations thus calculated, we can determine a scaling error as being equal to: the difference between the maximum position and the reference position if said difference is greater in absolute value than the difference between the minimum position and the reference position, and the difference between the minimum position and the reference position if said difference is greater in absolute value than the difference between the minimum position and the reference position to which is added an offset depending on the rotation speed of the coil, the difference between the maximum position and the reference position in other cases.

[0022] Another object of the invention relates to a system for detecting a spooling defect when winding a tie onto a reel driven in rotation around a longitudinal axis, the tie being guided by a guide pulley in alternating translation relative to the reel along said longitudinal axis between two inversion positions. Said system comprises: a first sensor adapted to measure the position of the guide pulley relative to the spool along the longitudinal axis over time, a second sensor adapted to measure the position of a device for regulating the speed of travel of the link on the guide pulley over time, a control unit configured to: (a) from measurement data from the first and second sensors, determine a deviation between the position of the regulating device and a reference position at each inversion position, and (b) from said deviation, detect the formation of a hollow or a bump in the winding.

[0023] In certain embodiments, the device for regulating the speed of movement of the link is a puppet comprising a pulley arranged at the end of an arm capable of pivoting around a horizontal axis against the return force of a spring, and in which the measured position is the angular position of the arm of the puppet relative to a vertical axis.

[0024] Another object of the invention relates to a system for winding a link onto a reel driven in rotation around a longitudinal axis, according to claim 5, comprising: a winder configured to drive the spool in rotation about the longitudinal axis, a pulley for guiding the link in alternating translation relative to the reel along the longitudinal axis between two inversion positions, so as to achieve regular helical winding of the link guided by the pulley on the reel, a regulating device arranged upstream of the guide pulley on the path of the link to regulate the running speed of the link, a system for detecting a shunting fault as described above.

[0025] In some embodiments, the winder is configured to drive the spool only in rotation, the system comprising an actuator configured to drive the guide pulley in translation along the longitudinal axis.

[0026] In other embodiments, the guide pulley is fixed and the winder includes an actuator configured to drive the spool in rotation and translation relative to the guide pulley.

[0027] Finally, the invention relates to a tie winder comprising a winding system as described above. BRIEF DESCRIPTION OF THE FIGURES

[0028] Other characteristics and advantages of the invention will emerge from the detailed description which follows, with reference to the appended drawings, in which: there Figure 1 is an overview of a system for winding a link onto a reel in which the method for detecting a spooling defect according to the invention is implemented: the Figure 2 is a schematic diagram of the position measurement of the link speed control device. DETAILED DESCRIPTION OF EMBODIMENTS

[0029] There Figure 1 is an overview of a system for winding a tie L onto a reel. Such a system is usually part of a winder, which is a machine whose function is to arrange said tie on a reel, for example after its manufacture or a test of the tie.

[0030] The link may be an electrical cable, an optical fiber or a bundle of optical fibers, a mechanical cable, a hydraulic or pneumatic conduit or any other suitable means for carrying a fluid or transmitting energy and / or signals.

[0031] The coil 1 comprises a cylindrical core 10 intended to receive the link in the form of regularly wound turns, and two flanges 11, 12 intended to retain the link on the core.

[0032] The coil is secured to a winder (not shown) comprising a motor adapted to drive the coil in rotation along a longitudinal axis X which is the axis of revolution of the cylindrical core 10.

[0033] The reel may be located at the outlet of a tie production machine, in particular an extrusion line, a tie testing machine, or any other machine through which the tie is passed before being wound onto the reel. The winder may be an integral part of the said machine or be juxtaposed with it.

[0034] The machine was not depicted on the Figure 1 , except for an output capstan 4, which has the function of applying mechanical tension in the link.

[0035] Between the capstan 4 and the reel are arranged a certain number of pulleys, one of which is designated by the reference 32 and the other is designated by the reference 21, but which have not necessarily all been represented on the Figure 1 .

[0036] The winding of the link on the reel is carried out in the form of helical layers with joined turns, obtained by combining two movements: the rotation of the coil around the X axis, the axial displacement (i.e. along the X axis) of the link, carried out by means of a spooling system, which has the function of carrying out a regular helical winding of the link on the coil by axially moving the entry point of the wire proportionally to the rotation of the coil.

[0037] Typically, the X axis is located in a horizontal plane, which is usually parallel to the ground plane of the facility in which the tie winding is implemented.

[0038] The shunting system includes a device for regulating the speed of the link and a link guide pulley.

[0039] The link speed regulation device is shown in the form of a puppet 3 which comprises an arm 31 which can pivot about an axis perpendicular to the X axis against the return force of a spring (not shown), and a pulley 30 arranged at the end of the arm opposite the pivot axis. On the Figure 1 , axis 31 is collinear with a vertical Z axis, but it can be tilted to one side or the other relative to this axis.

[0040] The angular position of the arm 31 is adjusted to regulate differences in the running speed of the link.

[0041] The guide pulley 2 is located between the puppet 3 and the spool 1 on the path of the link.

[0042] Pulley 2 has the function of bringing the link opposite the core of the coil to guide its winding.

[0043] The pulley 32, which is arranged upstream of the puppet on the path of the link, makes it possible to increase the locking on the puppet 30 and to keep the entry angle on the puppet constant.

[0044] Pulley 21 acts as a compensator configured so that the length between the puppet and the traverse system is the same regardless of the position of the guide pulley. Pulley 21 moves along the X axis by half a traverse step at each traverse step.

[0045] In the illustrated embodiment, the spool is fixed in translation and the guide pulley is movable in alternating translation along the X axis of the spool. The guide pulley 2 is thus secured to a belt 20. A motor (not shown) moves the belt in alternating translation along the X axis.

[0046] In an alternative embodiment (not shown), the guide pulley may be translationally fixed and the spool could be translationally movable (in addition to its rotational movement) along the X axis.

[0047] The movement of the guide pulley 2 relative to the spool is carried out alternately in both directions, between two inversion positions which are the extreme positions of movement of the guide pulley relative to the spool.

[0048] Said inversion positions are determined according to the position of the flanges, in order to ensure that the first and last turns of each helical sheet are positioned as close as possible to each flange, so as not to generate hollows in the outer surface of the sheets.

[0049] In practice, the inversion positions can be determined when loading a new coil, by measuring the positions of one of the flanges relative to the other which is considered as the origin of the measurement.

[0050] The cutting system comprises several sensors, which are usually present in cutting systems on the market and therefore do not need to be specifically added for the implementation of the invention.

[0051] A first sensor is used to measure the position of the guide pulley 2 relative to the spool 1 along the X axis over time. This sensor can, for example, be an encoder of the motor driving the belt attached to the guide pulley.

[0052] A second sensor measures the angular position of puppet 3 relative to the Z axis over time.

[0053] The system further comprises a control unit comprising at least one processor adapted to implement algorithms for calculating a cutting fault.

[0054] The control unit receives measurement data from the various sensors.

[0055] From this data, the processor determines a deviation between the angular position of the puppet and a reference angular position at each inversion position.

[0056] From the deviation thus determined, the processor detects the formation of a hollow or a hump in the winding.

[0057] There Figure 2 illustrates the principle of measuring the angular position of the puppet.

[0058] The x-axis is a time axis.

[0059] The y-axis represents the position of the guide pulley and the angular position of the puppet (arbitrary units).

[0060] The triangular graph P2 represents the evolution of the position of the guide pulley as a function of time. This position evolves periodically between two successive inversion positions Pi1 and Pi2, which correspond to the tips of the triangles.

[0061] Curve P3 represents the evolution of the angular position of the puppet relative to the Z axis over time.

[0062] The P3r curve represents the evolution of a reference angular position of the puppet relative to the Z axis over time. On the Figure 2 , we observe that said reference angular position takes two different constant values ​​during a forward and return movement of the guide pulley between the two inversion positions Pi1, Pi2.

[0063] Particularly advantageously, the angular position of the puppet is not measured punctually at each inversion position, but in a measurement time window F encompassing each inversion.

[0064] The reference angular position P3r can be determined as the arithmetic mean of the instantaneous angular positions of the puppet measured when the window is opened during a certain number of measurements (for example 50 measurements) preceding the current measurement, for the same inversion position Pi1 or Pi2. This makes it possible to smooth the measurement and avoid taking into account small disturbances without altering the useful signal linked to the real movement of the puppet.

[0065] Between the opening and closing of the said measurement window, the instantaneous angular position of the puppet is recorded. The minimum p3min and maximum p3max positions in the window F are determined and saved.

[0066] From these measurements, we determine, for each inversion position, a difference Δmin equal to the difference between the reference position P3r and the minimum angular position p3min of the puppet in the corresponding window, and a difference Δmax equal to the difference between the reference position P3r and the maximum angular position p3max of the puppet in said window.

[0067] Particularly advantageously, the deviation Δmin incorporates an offset applied to the minimum position p3min to take into account the fact that the puppet has a natural (decreasing) movement upon inversion. This offset is a function of the winding speed of the link. The control unit may comprise a memory in which different predetermined values ​​of the offset to be applied are recorded depending on the winding speed.

[0068] Comparing the absolute values ​​of the two deviations Δmin and Δmax in the same window makes it possible to detect a tendency towards the formation of a hollow or a hump in the winding.

[0069] Indeed, a hollow is characterized by a smaller winding radius of the link; consequently, for a given rotation speed of the coil, the wound length of link is smaller, which results in a displacement of the pad in the direction of an increase in the deviation Δmax. An absolute value of Δmax greater than the absolute value of Δmin is therefore representative of the formation of a hollow in the winding.

[0070] On the contrary, a hump is characterized by a larger winding radius of the link; therefore, for a given coil rotation speed, the wound link length is larger, which results in a displacement of the pad in the direction of an increase in the gap Δmin. An absolute value of Δmax lower than the absolute value of Δmin is therefore representative of the formation of a hump in the winding.

[0071] A swash error can then be defined as the largest absolute value of the deviations Δmax and Δmin. In the case where these two deviations have close values, the detection of a dip will be favored because the detection of a dip is more significant than that of a bump, which is biased by the offset that is not determined precisely. Thus, in practice, if the absolute value of Δmax is greater than that of Δmin, the swash error will be assigned the value Δmax. If the absolute value of Δmin is greater than the absolute value of Δmax to which an offset depending on the winding speed is added, the swash error will be assigned the value Δmin. If the absolute values ​​of Δmax and Δmin are close, the swash error will be assigned the value Δmax.

[0072] Since the amplitude of the puppet's oscillations increases with the rotation speed of the coil, it is possible to apply an error harmonization term, proportional to the speed of the coil, to have the same order of magnitude of the error for the same deviation, independently of the speed of the coil.

[0073] Although the description of the method for detecting the shunting defect has been made for a regulating puppet, frequently used in particular for winding thin and / or fragile links, of which an angular position relative to the vertical is measured, the person skilled in the art will be able to use any other regulating device equipped with a position sensor, and exploit the measurements of this position in a measurement window encompassing each inversion position, according to the same principle as that set out above.

[0074] Regardless of the control device used, the invention has the advantage of using a sensor integrated into this control device to detect a cutting fault, without requiring any additional measuring means. The implementation of the cutting fault detection therefore does not require any structural modification of the cutting system and can therefore be carried out at a lower cost.

Claims

1. A method for detecting a traverse winding defect when winding a link (L) on a spool (1) rotatably driven about a longitudinal axis (X), the link (L) being alternately translationally guided by a guide pulley (2) relative to the spool (1) along said longitudinal axis (X) between two reversal positions, comprising: - measuring the position of the guide pulley (2) relative to the spool (1) along the longitudinal axis (X) over time, - measuring the position (P2) of a regulation device for regulating the advance speed of the link on the guide pulley over time, said measurement being carried out in a measurement window (F) encompassing each reversal position (Pi1, Pi2), - from said measurements, determining a deviation between the position (P3) of the regulation device and a reference position (P3r) at each reversal position (Pi1, Pi2), and - from said deviation, detecting the formation of a hollow or bump in the winding, said method being characterised in that the minimum (p3min) and maximum (p3max) positions of the regulation device are determined in each measurement window (F) and deviations (Δmin, Δmax) between each respective minimum (p3min) or maximum (p3max) position and the reference position (P3r) of the regulation device are calculated.

2. The method according to claim 1, wherein the regulation device for regulating the advance speed of the link is a replica (3) comprising a pulley (31) arranged at the end of an arm (30) capable of pivoting about a horizontal axis against the return load of a spring, and wherein the measured position is the angular position of the arm of the replica (3) relative to a vertical axis (Z).

3. The method according to one of claims 1 or 2, comprising comparing the absolute values of the deviations (Δmin, Δmax) and determining: - the formation of a hollow in the winding if the absolute value of the deviation (Δmax) between the maximum position (p3max) and the reference position is greater than the absolute value of the deviation (Δmin) between the minimum position (p3min) and the reference position, - the formation of a bump in the winding if the absolute value of the deviation (Δmax) between the maximum position (p3max) and the reference position is less than the absolute value of the deviation (Δmin) between the minimum position (p3min) and the reference position.

4. The method according to one of claims 1 to 3, wherein a traverse winding error is determined to be equal to: - the deviation (Δmax) between the maximum position (p3max) and the reference position if the deviation (Δmax) is greater in absolute value than the deviation (Δmin) between the minimum position (p3min) and the reference position, and - the deviation (Δmin) between the minimum position (p3min) and the reference position if said deviation (Δmin) is greater in absolute value than the deviation (Δmax) between the minimum position (p3max) and the reference position to which an offset which a function of the rotation speed of the spool is added, - the deviation (Δmax) between the maximum position (p3max) and the reference position in other cases.

5. A system for detecting a traverse winding defect when winding a link (L) on a spool (1) rotatably driven about a longitudinal axis (X), the link (L) being alternately translationally guided by a guide pulley (2) relative to the spool along said longitudinal axis (X) between two reversal positions, comprising: - a first sensor adapted to measure the position of the guide pulley relative to the spool along the longitudinal axis over time, - a second sensor adapted to measure the position of a regulation device for regulating the advance speed of the link on the guide pulley over time in a measurement window (F) encompassing each reversal position (Pi1, Pi2), - a control unit configured to: (a) from the measurement data of the second sensor, determine the minimum (p3min) and maximum (p3max) positions of the regulation device in each measurement window (F) (b) from the measurement data of the first and second sensors, determine a deviation (Δmin, Δmax) between the position of the regulation device and a reference position (P3r) at each reversal position, and (c) from said deviation, detect the formation of a hollow or bump in the winding.

6. The system according to claim 5, wherein the regulation device for regulating the advance speed of the link is a replica (3) comprising a pulley (31) arranged at the end of an arm (30) capable of pivoting about a horizontal axis against the return load of a spring, and wherein the measured position is the angular position of the replica arm (3) relative to a vertical axis (Z).

7. A winding system for winding a link (L) on a spool (1) rotatably driven about a longitudinal axis (X), comprising: - a spooler configured to rotatably drive the spool (1) about the longitudinal axis (X), - a guide pulley (2) for alternately translationally guiding the link (L) relative to the spool (1) along the longitudinal axis (X) between two reversal positions, so as to perform an even helical winding of the link guided by the pulley on the spool, - a regulation device (3) arranged upstream of the guide pulley (2) on the path of the link (L) to regulate the advance speed of the link, - a system for detecting a traverse winding defect according to one of claims 5 to 6.

8. The system according to claim 7, wherein the spooler is configured to only rotatably drive the spool (1), the system comprising an actuator configured to translationally drive the guide pulley (2) along the longitudinal axis (X).

9. The system according to claim 8, wherein the guide pulley (2) is fixed and the spooler comprises an actuator configured to rotatably and translationally drive the spool (1) relative to the guide pulley (2).

10. A link winder comprising a winding system according to one of claims 7 to 9.

Images