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

[0001] METHOD AND SYSTEM FOR DETECTING A CUTTING DEFECT

[0002] FIELD OF INVENTION

[0003] The invention relates to a method and a system for detecting a slicing defect.

[0004] STATE OF THE ART

[0005] 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 reel, in order to be transported, stored and / or used.

[0006] Generally, it is necessary for the winding of the cable tie onto the reel to be regular, meaning that the tie is wound onto the reel in one or more successive layers of tightly packed turns or turns with minimal gaps between them. Such a regular winding ensures the mechanical integrity of the tie and also allows for unwinding the tie with a virtually constant tension.

[0007] To this end, the link winding system is equipped with a tracking system, which includes a guide pulley arranged opposite the reel, adapted to control the position of each new turn relative to the turns already laid on the reel core. During the winding of the link, the reel is driven in rotation around the axis of revolution of the core, and the guide pulley is driven in reciprocating translation relative to the reel (or vice versa) in a direction parallel to said axis, between two reversing positions located near each of the two reel flanges.

[0008] However, it may happen that, due to a faulty adjustment of the reversing positions of the guide pulley, too much length of the link accumulates in the vicinity of a flange of the reel, 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, creating a hollow on the outer surface of all the turns.

[0009] Indeed, the width of the reel, which corresponds to the distance between the two flanges, is not always known precisely. For example, if the reel is made of molded plastic, there can be significant dimensional variations between two similar reels.

[0010] Furthermore, as the link is wound onto the reel, the flanges can separate under the pressure of the link, affecting the reel's filling. Such a defect can be visually observed by an operator and corrected by adjusting the dimensions of the reversing positions.

[0011] However, this detection is not very precise and can only be performed when a significant winding defect has been observed, which is not satisfactory.

[0012] Document JPH09276932 describes a winding system for spooling an optical fiber onto a reel. The system comprises a motor with a rotary encoder, and a ball screw coupled to the motor and the reel to drive the reel in translational alternation in two winding directions relative to a fixed pulley. The motor changes its direction of rotation based on data from proximity sensors mounted on a support, which detect the position of the reel flanges. The device further includes a sensor for detecting the position of the optical fiber and a control device that controls the motor's direction of rotation based on a fiber speed signal at the pulley and a winding position signal provided by the encoder. A curve representing the fiber's position at the moment of a change in winding direction, detected by the sensor, is plotted.The presence of a bulge indicates an excess thickness in the winding at a coil flange. In response to the detection of such excess thickness, the control device adjusts the winding direction reversal position. This results in a reduction of the bulge at the next reversal position.

[0013] Document JPH08217333 describes a winding system comprising a sensor for measuring the distance between the axis of the guide pulley and one of the reel flanges. The timing of the change in winding direction is determined based on geometric considerations. The winding direction is reversed when the distance between the wire and the flange is less than half the wire diameter.

[0014] The document JPH08217330 describes a spooling system in which the speeds of wire movement and winding onto the reel are controlled by means of respective encoders, so as to equalize these two speeds.

[0015] DESCRIPTION OF THE INVENTION

[0016] One aim of the invention is to design a method for detecting a slicing defect that can be implemented automatically.

[0017] Advantageously, this detection method should also be compatible with an automatic correction method for the slicing defect.

[0018] To this end, the invention proposes a method for detecting a snag fault during the winding of a link onto a reel driven in rotation around a longitudinal axis, the link being guided by a guide pulley in alternating translation relative to the reel along said longitudinal axis between two inversion positions, comprising: - measuring the position of the guide pulley relative to the reel along the longitudinal axis over time, - measuring the position of a device regulating the speed of the link's movement on the guide pulley over time,

[0019] - from said measurements, the determination of a difference between the position of the regulating device and a reference position at each reversal position, and

[0020] - from said gap, the detection of the formation of a hollow or a bump in the winding.

[0021] According to one embodiment, the device for regulating the speed of scrolling 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 restoring force of a spring, and in which the measured position is the angular position of the arm of the puppet with respect to a vertical axis.

[0022] In this text, "horizontal" means a direction perpendicular to the direction of gravity, and "vertical" means the direction of gravity.

[0023] A particularly advantageous feature is that the measurement of the position of the control device is carried out within a measurement window encompassing each reversal position.

[0024] Preferably, the minimum and maximum positions of the control device are determined in each measurement window, and deviations are calculated between each respective minimum or maximum position and the reference position of the control device.

[0025] Most advantageously, the method includes comparing the absolute values ​​of said discrepancies and determining:

[0026] - the formation of a hollow in the winding if the absolute value of the difference between the maximum position and the reference position is greater than the absolute value of the difference between the minimum position and the reference position,

[0027] - the formation of a bump in the winding if the absolute value of the difference between the maximum position and the reference position is less than the absolute value of the difference between the minimum position and the reference position.

[0028] From the discrepancies thus calculated, a slicing error can be determined to be equal to:

[0029] - 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

[0030] - 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 plus an offset depending on the rotation speed of the coil,

[0031] - the difference between the maximum position and the reference position in other cases.

[0032] Another object of the invention relates to a system for detecting a snare fault during the winding of a link onto a reel rotated about a longitudinal axis, the link being guided by a guide pulley in alternating translation relative to the reel along said longitudinal axis between two reversing positions. Said system comprises:

[0033] - a first sensor adapted to measure the position of the guide pulley relative to the spool along the longitudinal axis over time,

[0034] - a second sensor adapted to measure the position of a device regulating the speed of the link's movement on the guide pulley over time,

[0035] - a control unit configured for:

[0036] (a) Using measurement data from the first and second sensors, determine the difference between the position of the control device and a reference position at each reversal position, and

[0037] (b) from said gap, detect the formation of a hollow or a bump in the winding.

[0038] In some embodiments, the device for regulating the speed of scrolling 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 restoring force of a spring, and in which the measured position is the angular position of the arm of the puppet with respect to a vertical axis.

[0039] Another object of the invention relates to a system for winding a link onto a reel driven in rotation around a longitudinal axis, comprising:

[0040] - a winding machine configured to drive the coil in rotation around the longitudinal axis,

[0041] - a guide pulley for the link in alternating translation relative to the spool along the longitudinal axis between two inversion positions, so as to achieve a regular helical winding of the link guided by the pulley on the spool,

[0042] - a regulating device arranged upstream of the guide pulley on the link's path to regulate the link's speed,

[0043] - a system for detecting a slicing defect as described above.

[0044] In some embodiments, the winder is configured to drive the coil only in rotation, the system comprising an actuator configured to drive the guide pulley in translation along the longitudinal axis.

[0045] In other embodiments, the guide pulley is fixed and the winder includes an actuator configured to drive the coil in rotation and translation relative to the guide pulley.

[0046] Finally, the invention relates to a link winder comprising a winding system as described above. BRIEF DESCRIPTION OF FIGURES

[0047] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the attached drawings, in which:

[0048] - Figure 1 is an overview of a link winding system on a reel in which the method for detecting a cutting defect according to the invention is implemented;

[0049] - Figure 2 is a schematic diagram of the position measurement of the link speed regulation device.

[0050] DETAILED DESCRIPTION OF IMPLEMENTATION METHODS

[0051] Figure 1 is an overview of a system for winding a link L onto a reel. Such a system is generally part of a winder, which is a machine whose function is to arrange said link onto a reel, for example after its manufacture or after a test of the link.

[0052] 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 transporting fluid or transmitting energy and / or signals.

[0053] 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.

[0054] The coil is attached to a winding machine (not shown) comprising a motor adapted to drive the coil in rotation around a longitudinal axis X which is the axis of revolution of the cylindrical core 10.

[0055] The reel may be located at the output of a link production machine, such as an extrusion line, a link testing machine, or any other machine in which the link is wound before being wound onto the reel. The winder may be an integral part of said machine or located next to it.

[0056] The machine has not been shown in Figure 1, except for an output capstan 4, which has the function of applying mechanical tension in the link.

[0057] Between the capstan 4 and the spool are arranged a number of pulleys, one of which is designated by the reference 32 and the other by the reference 21, but which have not necessarily all been represented in figure 1.

[0058] The winding of the link onto the reel is carried out in the form of helical sheets with contiguous turns, obtained by combining two movements:

[0059] - the rotation of the coil around the X-axis,

[0060] - the axial displacement (i.e. along the X axis) of the link, achieved by means of a winding system, which has the function of achieving a regular helical winding of the link on the spool by axially displacing the entry point of the wire proportionally to the rotation of the spool.

[0061] In general, the X axis is located in a horizontal plane, which is usually parallel to the floor plane of the installation in which the link winding is implemented.

[0062] The slack-traveling system includes a device for regulating the speed of the link's movement and a link guide pulley.

[0063] The link speed control device is represented as a puppet 3 comprising an arm 31 that pivots about an axis perpendicular to the X-axis against the restoring force of a spring (not shown), and a pulley 30 arranged at the end of the arm opposite the pivot axis. In Figure 1, the axis 31 is collinear with a vertical axis Z, but it can be inclined to one side or the other with respect to this axis.

[0064] The angular position of arm 31 is adjusted to regulate differences in link scrolling speed.

[0065] The guide pulley 2 is located between the puppet 3 and the spool 1 on the path of the link.

[0066] The function of pulley 2 is to bring the link to the side of the core of the spool to guide its winding.

[0067] The pulley 32, which is arranged upstream of the puppet on the path of the link, allows the clamping force on the puppet 30 to be increased and the entry angle on the puppet to be kept constant.

[0068] Pulley 21 acts as a compensator, configured to maintain a constant length between the puppet and the slewing system, regardless of the guide pulley's position. Pulley 21 moves along the X-axis by half a slewing step with each slewing step.

[0069] In the illustrated embodiment, the spool is fixed in translation and the guide pulley is movable in reciprocating translation along the X-axis of the spool. The guide pulley 2 is thus fixed to a belt 20. A motor (not shown) moves the belt in reciprocating translation along the X-axis.

[0070] In an alternative embodiment (not shown), the guide pulley can be fixed in translation and the spool could be mobile in translation (in addition to its rotational movement) along the X axis.

[0071] The movement of the guide pulley 2 relative to the spool is carried out alternately in both directions, between two reversing positions which are the extreme positions of movement of the guide pulley relative to the spool.

[0072] These inversion positions are determined based on 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.

[0073] In practice, the reversal 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 the origin of the measurement.

[0074] The scanning system includes several sensors, which are usually present in commercial scanning systems and therefore do not need to be specifically added for the implementation of the invention.

[0075] A first sensor measures the position of the guide pulley 2 relative to the coil 1 along the X-axis over time. This sensor could, for example, be an encoder for the motor driving the belt attached to the guide pulley.

[0076] A second sensor allows the angular position of puppet 3 relative to the Z axis to be measured over time.

[0077] The system further includes a control unit comprising at least one processor adapted to implement algorithms for calculating a slicing defect.

[0078] The control unit receives measurement data from the various sensors.

[0079] From this data, the processor determines a difference between the angular position of the puppet and a reference angular position at each inversion position.

[0080] From the gap thus determined, the processor detects the formation of a dip or a bump in the winding.

[0081] Figure 2 illustrates the principle of measuring the angular position of the puppet.

[0082] The x-axis is a time axis.

[0083] The ordinate axis represents the position of the guide pulley and the angular position of the puppet (arbitrary units).

[0084] 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 apexes of the triangles.

[0085] Curve P3 represents the evolution of the angular position of the puppet relative to the Z axis over time.

[0086] The curve P3r represents the evolution of a reference angular position of the puppet relative to the Z-axis over time. In Figure 2, we observe that this reference angular position takes on two different constant values ​​during a forward and return movement of the guide pulley between the two inversion positions Pi1, Pi2.

[0087] A particularly advantageous feature is that the puppet's angular position is not measured at a single point in time at each inversion, but rather within a measurement time window F encompassing each inversion. The reference angular position P3r can be determined as the arithmetic mean of the instantaneous angular positions of the puppet measured when the window was opened, during a number of measurements (e.g., 50 measurements) preceding the current measurement, for the same inversion position Pi1 or Pi2. This allows for smoother measurements and avoids the inclusion of small disturbances without altering the useful signal related to the puppet's actual movement.

[0088] Between the opening and closing of the measurement window, the instantaneous angular position of the puppet is recorded. The minimum position p3min and maximum position p3max in window F are determined and saved.

[0089] From these measurements, for each inversion position, we determine a gap Amin equal to the gap between the reference position P3r and the minimum angular position p3min of the puppet in the corresponding window, and a gap Amax equal to the gap between the reference position P3r and the maximum angular position p3max of the puppet in said window.

[0090] A particularly advantageous feature is that the Amin offset incorporates a shift applied to the minimum position p3min to account for the puppet's natural (decreasing) movement during inversion. This offset is a function of the link winding speed. The control unit may include a memory in which different predetermined offset values ​​are stored, depending on the winding speed.

[0091] Comparing the absolute values ​​of the two deviations Amin and Amax in the same window allows us to detect a tendency for the formation of a trough or a bump in the winding.

[0092] Indeed, a gap is characterized by a smaller winding radius of the link; consequently, for a given spool rotation speed, the wound link length is shorter, resulting in a displacement of the pad in the direction of an increase in the gap Amax. An absolute value of Amax greater than the absolute value of Amin is therefore indicative of the formation of a gap in the winding.

[0093] Conversely, a hump is characterized by a larger winding radius of the link; consequently, for a given spool rotation speed, the wound link length is greater, resulting in a displacement of the pad in the direction of an increase in the gap Amin. An absolute value of Amax lower than the absolute value of Amin is therefore indicative of the formation of a hump in the winding.

[0094] We can then define a cutting error as the greater of the absolute values ​​of the differences Amax and Amin. When these two differences are close, we prioritize detecting a dip because detecting a dip is more significant than detecting a bump, which is biased by the offset that is not precisely determined. Thus, in practice, if the absolute value of Amax is greater than that of Amin, we assign the value Amax to the cutting error. If the absolute value of Amin is greater than the absolute value of Amax plus an offset that is a function of the winding speed, we assign the value Amin to the cutting error. If the absolute values ​​of Amax and Amin are close, we assign the value Amax to the cutting error.

[0095] 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 error for the same deviation, regardless of the speed of the coil.

[0096] Although the description of the method for detecting the tracing defect was made for a regulating dummy, frequently used especially for winding thin and / or fragile links, whose angular position is measured relative to the vertical, a person skilled in the art may 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 explained above.

[0097] Regardless of the control device used, the invention has the advantage of using a sensor integrated into that control device to detect a cutting fault, without requiring any additional measuring means. Therefore, implementing the cutting fault detection does not require any structural modification of the cutting system and can thus be done at a lower cost.

Claims

DEMANDS 1. Method for detecting a snaking defect during the winding of a link (L) onto a reel (1) driven in rotation about a longitudinal axis (X), the link (L) being guided by a guide pulley (2) in reciprocating translation relative to the reel (1) along said longitudinal axis (X) between two reversing positions, comprising: - the measurement of the position of the guide pulley (2) relative to the spool (1) along the longitudinal axis (X) over time, - the measurement of the position (P2) of a device regulating the speed of the link's movement on the guide pulley over time, said measurement being carried out in a measurement window (F) encompassing each inversion position (PU, Pi2), - from said measurements, the determination of a difference between the position (P3) of the regulating device and a reference position (P3r) at each inversion position (PU, Pi2), and - from said deviation, the detection of the formation of a hollow or a bump in the winding, said method being characterized in that the minimum (p3min) and maximum (p3max) positions of the regulating device are determined in each measurement window (F) and deviations (Amin, Amax) are calculated between each respective minimum (p3min) or maximum (p3max) position and the reference position (P3r) of the regulating device.

2. Method according to claim 1, wherein the link scroll speed regulation device is a puppet (3) comprising a pulley (31) arranged at the end of an arm (30) capable of pivoting about a horizontal axis against the restoring force of a spring, and wherein the measured position is the angular position of the arm of the puppet (3) with respect to a vertical axis (Z).

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

4. A method according to any one of claims 1 to 3, wherein a slicing error is determined to be equal to: - the difference (Amax) between the maximum position (p3max) and the reference position if said difference (Amax) is greater in absolute value than the difference (Amin) between the minimum position (p3min) and the reference position, and - the difference (Amin) between the minimum position (p3min) and the reference position if said difference (Amin) is greater in absolute value than the difference (Amax) between the minimum position (p3max) and the reference position plus an offset depending on the rotation speed of the coil, - the difference (Amax) between the maximum position (p3max) and the reference position in other cases.

5. System for detecting a fault in winding a link (L) onto a reel (1) driven in rotation about a longitudinal axis (X), the link (L) being guided by a guide pulley (2) in alternating translation relative to the reel along said longitudinal axis (X) between two reversing 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 device regulating the speed of the link on the guide pulley over time in a measurement window (F) encompassing each inversion position (Pi1, Pi2), - a control unit configured for: (a) From measurement data from the second sensor, determine the minimum (p3min) and maximum (p3max) positions of the control device in each measurement window (F) (b) from measurement data from the first and second sensors, determine a deviation (Amin, Amax) between the position of the control device and a reference position (P3r) at each reversal position, and (c) from said deviation, detect the formation of a hollow or a bump in the winding.

6. System according to claim 5, wherein the link scroll speed regulation device is a puppet (3) comprising a pulley (31) arranged at the end of an arm (30) capable of pivoting about a horizontal axis against the restoring force of a spring, and wherein the measured position is the angular position of the arm of the puppet (3) with respect to a vertical axis (Z).

7. A system for winding a link (L) onto a reel (1) driven in rotation about a longitudinal axis (X), comprising: - a winding machine configured to drive the coil (1) in rotation around the longitudinal axis (X), - a guide pulley (2) for the link (L) in alternating translation relative to the spool (1) along the longitudinal axis (X) between two inversion positions, so as to achieve a regular helical winding of the link guided by the pulley on the spool, - a regulating device (3) arranged upstream of the guide pulley (2) on the path of the link (L) to regulate the speed of the link's movement, - a system for detecting a slicing defect according to one of the claims 5 to 6.

8. System according to claim 7, wherein the winder is configured to drive the coil (1) only in rotation, the system comprising an actuator configured to drive the guide pulley (2) in translation along the longitudinal axis (X).

9. A system according to claim 8, wherein the guide pulley (2) is fixed and the winder comprises an actuator configured to drive the coil (1) in rotation and translation relative to the guide pulley (2).

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