Method for determining a cable state of a hoisting cable of a hoisting system

Abstract

The invention relates to a method for determining a rope condition of a hoisting rope (20) and a hoisting system (10), wherein a sensor device (25) with at least a first sensor unit (70), a data memory (35) and a hoisting rope (20) are provided, wherein the hoisting rope (20) is moved past the first sensor unit (70) over an available rope length, wherein the first sensor unit (70) generates a first sensor signal, wherein a first signal profile of the first sensor signal is determined as a function of the first rope position (p1(I)) as a first reference characteristic (100) of the hoisting rope (20), wherein a rope section (110) of the hoisting rope (20) is measured at the first sensor unit (70), wherein the first sensor unit (70) generates a second sensor signal as a function of a second rope position (p2(I)) of the hoisting rope (20), wherein a second signal profile (120) is determined as a function of the second rope position (p2(I)) is determined,wherein the second signal curve (120) is assigned to a subsection (116) of the first reference characteristic (100), wherein the subsection (116) of the first reference characteristic (100) assigned to the second signal curve (120) is updated by the second signal curve (120), wherein the updated reference characteristic is stored as a second reference characteristic (125).

Description

[0001] The invention relates to a method for determining the condition of a lifting rope of a lifting system according to claim 1.

[0002] From EP 4 065 498 A1, an arrangement for monitoring an elevator having an elevator rope is known. In this arrangement, the elevator rope is guided past an inductive sensor, which is positioned such that a magnetic field generated by the inductive sensor, extending at least partially over the elevator rope, is evaluated by a control device.

[0003] US Patent 5,804,964 A discloses a device for online testing of magnetizable ropes, comprising permanent magnets, various magnetic sensors, and an evaluation unit. The signals generated by faults in the rope under test are evaluated and weighted for each sensor type, from which an overall damage index for the rope is then determined.

[0004] From WO 2012 / 100938 A1, a device for detecting the discard maturity of a high-strength fiber rope is known, which detects one or more rope characteristics using different detection means based on optical, mechanical, or magnetic principles and evaluates them using an evaluation unit. Discard maturity is signaled when one or more of the detected rope characteristics or derived sum parameters, or their changes, exceed predefined limit values.

[0005] The object of the invention is to provide an improved method for determining the condition of a lifting rope of a lifting system.

[0006] This problem is solved by means of a method according to claim 1. Advantageous embodiments are specified in the dependent claims.

[0007] It was recognized that an improved method for determining the condition of a lifting rope in a lifting system, and an improved lifting system for a large industrial plant and / or other goods handling facility, can be provided by supplying a sensor device with at least one first sensor unit, a data storage device, and a lifting rope of the lifting system. The lifting rope is moved past the first sensor unit over an available length, with the first sensor unit generating a first sensor signal that characterizes an interaction between the first sensor unit and the lifting rope moving past it, depending on a first position of the lifting rope. A first signal profile of the first sensor signal is determined as a first reference characteristic of the lifting rope, depending on the first rope position, and stored in the data storage device.A section of the lifting rope, less than or equal to the available rope length, is moved past the first sensor unit after the first reference characteristic of the lifting rope has been determined. The first sensor unit generates a second sensor signal, which characterizes the interaction between the first sensor unit and the rope section moving past it, depending on the second position of the lifting rope. A second signal profile of the second sensor signal is determined as a function of the second rope position. This second signal profile is assigned to a subsection of the first reference characteristic, and the subsection of the first reference characteristic assigned to the second signal profile is updated by the second signal profile of the second sensor signal. The updated reference characteristic is stored in the data memory as the second reference characteristic.

[0008] This design has the advantage that the second reference characteristic can be determined during operation of the lifting system. This eliminates the need for downtime or maintenance interruptions to determine the second reference characteristic. Therefore, the method is particularly suitable for large industrial plants that operate essentially without interruption throughout the day and / or month.

[0009] In a further embodiment, the sensor device comprises a second sensor unit, which is arranged at a distance from the first sensor unit and is in contact with the lifting rope. The second sensor unit provides information about the first direction of travel of the lifting rope as it passes the second sensor unit over the available rope length, thereby determining the first reference characteristic. The second sensor unit also provides information about the second direction of travel of the lifting rope as it passes the second sensor unit. Depending on the second direction of travel of the rope, the second sensor signal is further processed such that the first reference characteristic and the second signal profile are determined for the same direction of travel.This design has the advantage that the direction of travel can be reliably determined by the second sensor unit, so that a reliable analysis and assignment of the second sensor profile to the first reference characteristic is possible with only minor deviations.

[0010] In a further embodiment, the second sensor unit comprises a speed sensor. When the lifting rope moves along its available length, the speed sensor provides a first speed signal corresponding to the speed of the lifting rope passing the first sensor unit. When the lifting rope moves along its length, the speed sensor provides a second speed signal corresponding to the speed of the rope passing the first sensor unit. The speed sensor thus allows for the simple determination of information about the movement of the lifting rope.

[0011] In another embodiment, the second sensor unit has a rolling element coupled to the speed sensor. The rolling element rests against the lifting rope. As the lifting rope moves, the rolling element rolls along the lifting rope, and the speed sensor provides either the first or the second speed signal, with the first direction of travel being determined based on the first speed signal and the second direction of travel based on the second speed signal. This design has the advantage that the first and / or second speed of the lifting rope can be reliably determined by the rolling element along the lifting rope and the mechanical connection of the second sensor unit to the lifting rope.

[0012] In another embodiment, the second sensor unit is arranged at a predefined distance from the first sensor unit, with the detection of the lifting rope beginning at a starting point using the first sensor unit. The first rope position relative to the starting point is determined as a function of the first speed signal. This allows the first rope position to be reliably determined and a particularly accurate first reference characteristic to be established.

[0013] In a further embodiment, the second signal waveform of the sensor signal is assigned to the first reference characteristic by means of pattern recognition, in particular cross-correlation, and / or in particular a time-warping algorithm, in particular a dynamic time-warping algorithm, and / or a self-learning algorithm. This compensates for rope elongation caused by heavy loads or progressive aging of the lifting rope, thus enabling reliable assignment of the second signal waveform to the first reference characteristic even when the lifting rope is stretched.

[0014] In a further embodiment, the first reference characteristic is linked to a first time signal from the time of acquisition of the first sensor signal and stored with this first time signal. The second reference characteristic is linked to a second time signal from the time of acquisition of the second sensor signal and stored. This allows an epigenetic fingerprint of the lifting cable, which changes over the lifespan of the lifting cable, to be stored in the data memory.

[0015] In another embodiment, the second reference characteristic is evaluated based on the first reference characteristic, whereby a condition of the lifting rope is determined and output based on the result of the evaluation. By repeating the process multiple times and saving the most recent reference characteristic each time, a history of the lifting rope can be created, which offers additional evaluation options during a lifting rope inspection.

[0016] In a further embodiment, the second speed at the second rope position is compared with a predefined minimum speed. If the second speed at the second rope position exceeds the minimum speed, the second sensor signal is taken into account to determine the second rope movement. Conversely, if the second speed at the second rope position falls below the minimum speed, the second sensor signal is not taken into account to determine the second rope movement. This design has the advantage of avoiding implausible second sensor signals due to the minimum speed. For example, the minimum speed can be at least 0.1 m / s, and in particular at least 0.2 m / s. However, the speed at which the lifting rope is moved should not exceed 50 m / s.

[0017] In a further embodiment, the first sensor signal and / or the second sensor signal is smoothed and / or pre-filtered before being evaluated, wherein, in particular, a Fast Fourier Transform and / or a Wavelet Transform, especially a Direct Wavelet Transform, and / or a low-pass filter is applied for filtering. Additionally or alternatively, the first sensor signal and / or the second sensor signal is compared with a predefined minimum threshold, wherein the first signal profile is determined based on the first sensor signal exceeding the predefined minimum threshold, and the second signal profile is determined based on the second sensor signal exceeding the predefined minimum threshold. The minimum threshold can, for example, be 5 percent to 10 percent of an expected maximum flux leakage rate.This allows noise to be filtered out in healthy areas of the lifting rope.

[0018] In another embodiment, the rope length is determined to ascertain the second signal profile after a predefined time interval, for example, from 1 hour up to and including 12 hours, or after a predefined number of lifting cycles. This design has the advantage of ensuring reliable evaluation and determination of the first and second reference characteristics. This allows the lifting rope to be regularly evaluated and analyzed, for example, at shift changes and as needed. Furthermore, this design offers the advantage that the evaluation of the reference characteristics enables automated analysis, such as trend analysis or indications of frequently worn rope sections.

[0019] In a further embodiment, the available rope length is advanced at the first sensor unit at at least a predefined minimum speed, wherein the minimum speed is preferably at least inclusive of 0.1 m / s, in particular at least inclusive of 0.2 m / s.

[0020] An improved lifting system can be provided by designing the lifting system specifically for a large industrial plant, in particular a rolling mill and / or a continuous casting machine and / or a goods handling area, wherein the lifting system is designed to carry out the method described above. Furthermore, the lifting system comprises at least one lifting cable, wherein the lifting system has a lifting capacity on the lifting cable of at least 20 t.

[0021] The invention is explained in more detail below with the aid of figures. These show: FIG 1 a schematic representation of a lifting system according to a first embodiment; FIGS 2A and 2 legs sensor device of the FIG 1 The lifting system shown is depicted from different perspective views of the lifting rope; FIG 3 is a flowchart of a method for operating the system shown in the FIGN 1 and 2A, 2B The lifting system shown; FIG 4 a schematic first diagram of a first reference characteristic; FIG 5 a schematic second diagram of a second signal waveform of a second sensor signal over a second rope position; and FIG 6 a second reference characteristic of the ... in the FIGN 1 and 2 The lifting rope shown; FIG 7 a second reference characteristic of a lifting rope ready for disposal; FIG 8 a schematic representation of a lifting system according to a second embodiment; and FIG 9 a sensor device of the in FIG 8 shown lifting system.

[0022] FIG 1 Figure 1 shows a schematic representation of a lifting system 10 according to a first embodiment.

[0023] The lifting system 10 is designed, for example, as a crane, in particular as a gantry crane. The lifting system 10 can be installed, for example, in a production plant, such as in a building housing a continuous casting machine or a casting-rolling composite plant, or in another building used for steel or metal production, in order to lift heavy objects, in particular ladles, by means of a lifting cable 20. The lifting system 10, and in particular the lifting cable 20, is subject to high loads and corresponding wear and aging.

[0024] To determine wear and aging, the lifting system 10 includes, in addition to the lifting rope 20, a control unit 15, a sensor device 25, a lifting device 30 and a support device 31.

[0025] The control unit 15 has a data storage device 35, an evaluation unit 40, and a data interface 45. The data interface 45 is connected to the evaluation unit 40 via a first data connection 50. Furthermore, the evaluation unit 40 is connected to the data storage device 35 via a second data connection 55. The data interface 45 is in turn connected to the sensor unit 25 via a third data connection 60.

[0026] The support structure 31 can, for example, be a trolley (in Figur 1 (not shown) which is arranged to be movable along a crane bridge 33 of the lifting system 10.

[0027] The lifting device 30 can, for example, include a drive unit, which is arranged, for example, on the trolley. The drive unit is designed to wind or unwind the lifting rope 20 and to lift or lower loads by means of the lifting rope 20 or, for example, the lifting device arranged on it.

[0028] In the operation of the lifting system 10, the lifting rope 20 is frequently moved. The lifting rope 20 has a large number of stranded wires. The wires can be made of, for example, ferromagnetic and / or austenitic steel. Over its service life, the lifting rope 20 wears down due to two factors: firstly, the loads lifted by the lifting rope 20 and the associated elongation of the rope; and secondly, the bending of the lifting rope 20, which occurs, for example, when winding and unwinding the lifting rope 20. This leads to wire breaks. Over its service life, the lifting rope 20 wears down because individual wires of the lifting rope 20 break locally. If breaks occur frequently over a predefined length, the lifting rope 20 is considered worn out and must be replaced to prevent an unintentional tearing of the lifting rope 20, for example under heavy loads, or an unintentional further breakage.

[0029] The sensor device 25 is mechanically connected to the trolley and arranged on the lifting rope 20. The sensor device 25 remains on the trolley during operation of the lifting system 10 and is not removed. The lifting rope 20 is guided through the sensor device 25.

[0030] FIGN 2A und 2B show the sensor device 25 of the in FIG 1 The lifting system 10 shown is depicted from different perspective views on the lifting cable 20.

[0031] The sensor device 25 comprises a guide roller arrangement 65, a first sensor unit 70, and at least one second sensor unit 75. The guide roller arrangement 65 is configured to guide the lifting rope 20 within the sensor device 25 and to define a predefined distance between the first sensor unit 70 and the lifting rope 20.

[0032] The first sensor unit 70 can, for example, comprise a magnetic field generator and a magnetic field sensor. The magnetic field generator can, for example, comprise an electric coil or a permanent magnet that acts on the lifting rope 20. The magnetic field sensor is configured to provide a first sensor signal corresponding to the lifting rope 20 as it passes through the magnetic field of the magnetic field generator.

[0033] The second sensor unit 75 can, for example, comprise a roller element 80 and a speed sensor 90, wherein the roller element 80 bears against the lifting rope 20 at least at one contact point 85. In the first embodiment of the lifting system 10, the roller element 80 can, for example, be configured as a speedometer wheel 81. Other configurations of the roller element 80 are also possible. In particular, the roller element 80 can, for example, be omitted. When the lifting rope 20 is moved, the roller element 80 rolls along the lifting rope 20. The speed sensor 90 detects a first speed of the lifting rope 20 as it passes the second sensor unit 75. The contact point 85 is arranged at a distance a from the first sensor unit 70. Furthermore, it is also possible for the first speed of the lifting rope 20 to be determined contactlessly by the speed sensor 90.In this case, for example, the speed sensor 90 can be arranged at a distance a from the first sensor unit 70.

[0034] FIG 3 shows a flowchart of a procedure for operating the in the FIGN 1 and 2A, 2B Lifting system shown 10. FIG 4 shows a schematic first diagram of a first reference characteristic 100. FIG 5 shows a schematic second diagram of a second signal curve 120 of a second sensor signal over a second rope position p2(I). FIG 6 shows a second reference characteristic 125 of the one in the FIGN 1 and 2 shown lifting rope 20.

[0035] The procedure described below is preferably carried out over the entire service life of the lifting rope 20 and is repeated regularly in parts. For this purpose, the lifting rope 20 is preferably mounted on the lifting device 30 at the beginning of its service life, preferably in a new or barely worn condition.

[0036] In the data storage device 35, a minimum speed and preferably a predefined reference length are stored before the start of the process. The minimum speed can be at least 0.1 m / s, and in particular at least 0.2 m / s.

[0037] In a first process step 305, the lifting rope 20 is mounted in the lifting system 10 in a substantially new or barely worn condition and the sensor device 25 is permanently mounted on the lifting rope 20, so that during every lifting or lowering operation or during every movement of the lifting rope 20 by the lifting device 30 the lifting rope 20 is guided past the sensor device 25.

[0038] In a second process step 310, for example, the lifting rope 20 is completely unwound or completely wound up. Once the lifting rope 20 is wound up or completely unwound, a starting point 95 of the lifting rope 20 is established. The starting point 95 serves as a reference point on the lifting rope 20. The first rope position p1(I) can be referenced to and related to the starting point 95. The starting point 95 thus serves as the "zero point" for the first rope position.

[0039] In a third process step 315, the lifting rope 20 is guided past the sensor device 25 at the minimum speed in a first direction of travel, starting from the starting point 95. The sensor device 25 is activated in the third process step 315.

[0040] For example, the magnetic field generator provides a magnetic field. The magnetic field of the magnetic field generator acts on the lifting rope 20 and the individual wires of the lifting rope 20. The material of the lifting rope 20 alters the magnetic field flux. In this embodiment, the magnetic field sensor is arranged at a distance from the magnetic field generator and provides a first sensor signal depending on the detected magnetic field. The first sensor signal is transmitted via the third data connection 60 to the data interface 45 and from the data interface 45 via the first data connection 50 to the evaluation unit 40. The evaluation unit 40 detects the first sensor signal. The minimum speed ensures that the first sensor signal can be further processed by the evaluation unit 40.

[0041] The evaluation unit 40 can filter and / or smooth the first sensor signal before further processing, or the control unit 15 can have an additional first filter for filtering and / or a first smoother for smoothing the first sensor signal, wherein in particular a Fast Fourier Transform and / or a Wavelet Transform, in particular a Direct Wavelet Transform, is used for filtering.

[0042] In the third process step 315, the rolling element 80, designed as a speedometer wheel 81, rolls along the lifting rope 20, and the speed sensor 90 provides information about the initial speed of the lifting rope 20 via the third data connection of the data interface 45 and via the first data connection 50 of the evaluation unit 40 as part of a first speed signal. The evaluation unit 40 records the first speed signal. The initial direction of travel can be determined based on the first speed signal and the starting point 95.

[0043] The evaluation unit 40 can filter and / or smooth the first speed signal before further processing, or the control unit 15 can have an additional second filter for filtering and / or a second smoother for smoothing the first speed signal, wherein in particular a Fast Fourier Transform and / or a Wavelet Transform, a Direct Wavelet Transform is used for filtering.

[0044] Starting from the starting point 95, the lifting rope 20 is wound or unwound over an available rope length to, for example, a maximum movable end 105, and is guided past the sensor device 25.

[0045] In a fourth process step 320 following the third process step 315, the evaluation unit 40 determines a first rope position p1(I) relative to the starting point 95, corresponding to the first sensor signal received, based on the distance a and the speed information of the first speed signal via the lifting rope 20. In other words, a first rope position p1(I) of the corresponding first sensor signal is determined at a distance of a certain length of the lifting rope 20 from the starting point 95.

[0046] In a fifth process step 325 following the fourth process step 320 (see FIG 4 The evaluation unit 40 determines a first signal profile of the first sensor signal for the respective first rope position p1(I) between the starting point 95 and the end 105. The evaluation unit 40 stores the first signal profile in the data memory 35 as the first reference characteristic 100. Furthermore, the evaluation unit 40 stores information about the first direction of travel with which the first reference characteristic 100 was determined.

[0047] Furthermore, the evaluation unit 40 preferably stores initial time information associated with the first reference characteristic 100, which essentially corresponds to the acquisition time of the first sensor signal. The first reference characteristic 100 forms an initial fingerprint of the lifting rope 20, which is unique to the respective lifting rope 20.

[0048] The first sensor signal correlates with a change in stray flux D of a magnetic flux in the lifting rope 20. The change in stray flux D of the first sensor signal corresponds to an interruption / weakening of the magnetic flux, for example due to one or more wire breaks at the associated first rope position p1(I).

[0049] The first reference characteristic 100 (see Figur 4 For example, the first sensor signal exhibits a jagged initial signal profile across the first rope position p1(I). The greater the amplitude of the first sensor signal at an associated first rope position p1(I), the stronger the change in stray flux D at that associated first rope position p1(I). Therefore, if the first sensor signal has a high amplitude, the lifting rope 20 exhibits an irregularity, in particular one or more wire breaks, at the associated first rope position p1(I).

[0050] The first to fifth process steps 305 to 325, for example, represent an initialization process of the lifting rope 20. The initialization process can be carried out during or shortly after the installation of the lifting rope 20 in the lifting system 10.

[0051] After the initialization process, the lifting system 10 can be used as intended to raise or lower loads using the lifting rope 20. The following process steps are performed cyclically and regularly during the use of the lifting rope 20. It is particularly advantageous if, for example, these process steps are performed at shift changes, such as every eight hours. Of course, other time intervals are also possible. The following process steps are started and carried out automatically, preferably by the control unit 15. At the beginning of these process steps, the lifting rope 20 does not need to be fully wound or unwound, but can also be in an intermediate position between the starting point 95 and the end 105 at the sensor device 25.

[0052] In a sixth process step 330, a rope section 110 of the lifting rope 20 is preferably guided past the sensor device 25 at the minimum speed. The rope section 110 can lie between the starting point 95 and an end 105 of the lifting rope 20. The rope section 110 can be shorter than the maximum rope length of the lifting rope 20 between the starting point 95 and the end 105. However, the rope section 110 can also extend over the maximum rope length of the lifting rope 20 between the starting point 95 and the end 105. The rope section 110 begins at a rope section starting point 111 and ends at a rope section end point 112.

[0053] Analogous to the third process step 315, based on the interaction between the first sensor unit 70 and the passing lifting rope 20, the first sensor unit 70 provides a second sensor signal instead of the first. The second sensor signal is transmitted via the third data connection 60 to the data interface 45 and from the data interface 45 via the first data connection 50 to the evaluation unit 40. The evaluation unit 40 acquires the second sensor signal. The minimum speed ensures that the second sensor signal can be further processed by the evaluation unit 40.

[0054] The second sensor signal correlates with a change in the leakage flux D of the magnetic flux at a second rope position p2(I) in the rope section 110 of the lifting rope 20. The change in leakage flux D of the second sensor signal corresponds to an interruption and / or attenuation and / or a change in the magnetic flux, for example due to one or more wire breaks, within the lifting rope 20.

[0055] In the sixth process step 330, the unwinding element 80 unwinds along the lifting rope 20 offset from the rope section 110, and the speed sensor 90, driven by the unwinding element 80, provides information about a second speed of the lifting rope 20 via the third data connection 60 of the data interface 45 and via the first data connection 50 of the evaluation unit 40 as part of a second speed signal. The evaluation unit 40 receives the second speed signal.

[0056] In a seventh process step 335 following the sixth process step 330, the evaluation unit 40 determines the second rope position p2(I) based on the distance a and the speed information of the second speed signal. In this seventh process step 335, the second rope position p2(I) represents information about the rope section 110, which has already passed the first sensor unit 70, and its starting point 111. In the seventh process step 335, the second rope position p2(I), the starting point 111, and the endpoint 112 of the rope section do not yet have an assignment to the starting point 95 of the first reference characteristic 100, but only refer to the determined starting point 111 of the rope section 110 that has passed the first sensor unit 70.

[0057] At the end of the cable section 110, which passes the first sensor unit 70, the cable section endpoint 112 is reached. In the sixth and seventh process steps 330, 335, the start of the acquisition of the second velocity signal at the cable section startpoint 111 on the cable section 110 thus serves as a reference for the second cable position p2(I).

[0058] In an eighth process step 340 following the seventh process step 335, the evaluation unit 40 compares the second speed at the second rope position p2(I) with the minimum speed stored in the data memory 35. If the minimum speed is not reached, the subsequent process steps are not continued for the respective second sensor signal assigned to the second rope position p2(I). If the minimum speed is exceeded by the second speed at the second rope position p2(I), the evaluation unit 40 proceeds with the ninth process step 345.

[0059] In the ninth process step 345, the evaluation unit 40 determines a second signal profile 120 of the second sensor signal for the respective assigned second rope position p2(I) of the rope area 110.

[0060] Furthermore, the evaluation unit 40 checks, based on the second speed signal, a second direction of travel in which the lifting rope 20 was guided past the sensor device 25 in the sixth process step 330. If the second direction of travel corresponds to the first direction of travel of the first reference characteristic 100, the evaluation unit 40 continues with the determined second signal profile 120. If the second direction of travel is opposite to the first direction of travel, the evaluation unit 40 inverts the second speed signals and updates the second signal profile 120 of the second sensor signals accordingly via the second rope position p2(I) within the rope range 110.

[0061] In a tenth process step 350 following the ninth process step 345, the evaluation unit 40 compares, for example, the second signal waveform 120 of the second sensor signal with the first reference characteristic 100 as part of pattern recognition. If the second signal waveform 120 substantially matches the first reference characteristic 100 with respect to the second cable section 110, the evaluation unit 40 assigns the second signal waveform 120 to a subsection 116 of the first reference characteristic 100. In particular, the evaluation unit 40 can assign the second signal waveform 120 to the first reference characteristic 100 based on recurring patterns or motifs. Deviations between the second signal waveform 120 and the first reference characteristic 100 may exist. These deviations may be caused, for example, by wire breaks that occurred in the interim.

[0062] To account for rope elongation, the evaluation unit 40 can apply a time-warping algorithm, in particular a dynamic time-warping algorithm, to achieve improved agreement between the second signal waveform 120 of the second sensor signal related to the rope length 110 and the first reference characteristic 100 within the framework of pattern recognition. This allows the evaluation unit 40, for example, to compensate for rope elongation of the lifting rope 20 over its service life. Additionally or alternatively, cross-correlation and / or a self-learning algorithm can also be applied for this purpose.

[0063] By assigning the second signal waveform 120 to the subsection 116 of the first reference characteristic 100, the evaluation unit 40 can reliably assign the second rope position p2(I) of the second sensor signal to the respective first rope position p1(I) of the first reference characteristic 100 on the basis of the first reference characteristic 100.

[0064] In the eleventh procedural step 355 (see FIG 6 ) the evaluation unit 40 replaces the subsection 116 of the first reference characteristic 100 with the second signal profile 120 of the second sensor signal and thereby updates the first reference characteristic 100 by the second signal profile 120 in the corresponding subsection 116 to a second reference characteristic 125.

[0065] The updated reference characteristic 125 is stored by the evaluation unit 40 as a second reference characteristic 125 in the data memory 35, along with a second time information that essentially corresponds to the time of acquisition of the second sensor signal. The first reference characteristic 100 remains stored in the data memory 35 with the first time information and is preferably not deleted.

[0066] The evaluation unit 40 can automatically repeat process steps six through eleven (330 to 355) after a predefined time interval, for example, 1 to 12 hours, or after a predefined number of lifting cycles have been performed over the service life of the lifting rope. In this case, the currently generated second reference characteristic 125 becomes the first reference characteristic 100, updated based on a newly recorded rope section 110. The newly recorded rope section 110 can differ both in its position relative to the first rope position p1(I) and in its length from the previously recorded rope section 110. For example, process steps six through eleven (330 to 355) can be repeated regularly at intervals of 1 to 12 hours over the service life of the lifting rope 20.

[0067] By updating the previously created first reference characteristic 100 to the second reference characteristic 125, reliable pattern recognition is ensured during further passes of the rope section 110 with further wear of the lifting rope 20, and a reliable assignment of the rope section 110 is enabled.

[0068] In a twelfth process step 360, the evaluation unit 40, for example, evaluates the updated reference characteristic, in this embodiment for example the second reference characteristic 125, against the (first) original reference characteristic 100, for example as part of a comparison. During the evaluation, for example, at least one wire break and / or multiple wire breaks and a rope position p1(I) corresponding to the wire break can be determined. The wire break can be determined, for example, by a deviation in the amplitude of the second reference characteristic 125 from the first reference characteristic 100.

[0069] The wire break can be stored in the data storage unit 35 with an assignment to the first rope position p1(I) and, if desired, output by the evaluation unit 40 via the data interface 45.

[0070] In particular, the evaluation unit 40 can determine a number of wire breaks per reference length based on the predefined reference length. The reference length can, for example, correspond to six times the outer diameter or, for example, thirty times the outer diameter of the lifting rope 20. To do this, the evaluation unit 40 sums up the wire breaks and / or multiple wire breaks determined within the predefined reference length.

[0071] Based on the determined number of wire breaks per reference length, the evaluation unit 40 can also determine a failure probability of the lifting rope 20 or an updated remaining service life of the lifting rope 20 based on the first and second time information.

[0072] The number of wire breaks or the respective assigned rope position p1(I) to the wire breaks can be output by the evaluation unit 40 as part of a rope report via the lifting rope 20 to the data interface 45, so that a manual inspection of the respective critical points can be carried out by a corresponding expert.

[0073] The evaluation unit 40 can regularly repeat process steps six to twelve (330 to 360), whereby, for example, different rope sections 110 are passed by the sensor unit 25 each time, so that the corresponding second sensor signal is different each time. In this way, the evaluation unit 40 can gradually update the most recent second reference characteristic 125 over the service life of the lifting rope 20, so that the rope aging is reflected, for example, in the updated version of the second reference characteristic 125 (see, for example, [reference]). FIG 6 ) reflects.

[0074] FIG 7 A second reference characteristic 125 of a discarded lifting rope 20 is shown. It is clearly evident that the most recent second reference characteristic 125 exhibits numerous strong amplitudes in the change in leakage flux D, which correlate with a large number of wire breaks.

[0075] Because with each pass of a different rope section 110 the existing last reference characteristic is updated by the second signal profile 120 to the updated second reference characteristic 125, and the outdated reference characteristic 100 continues to be stored, a kind of epigenetic fingerprint of the lifting rope 20 is obtained. The reference characteristics 100 stored in the data memory 35 each represent an aging profile of the lifting rope 20.

[0076] Through use, the lifting rope 20 changes and ages. Rope anomalies occur, especially wire breaks. These wire breaks can accumulate, particularly in frequently used sections of the lifting rope 20, until the load-bearing capacity of the lifting rope 20 is reduced by the numerous wire breaks or the lifting rope 20 is no longer load-bearing. FIG 7 Such aging, especially in the area shortly before the end 105 of the lifting cable 20, can be recognized by the significant change in the scattering flux change D compared to the first reference characteristic 100.

[0077] The epigenetic fingerprint and the initial reference characteristic, along with its respective time information, which is stored in data memory 35 during the update of the latest reference characteristic, provide a history of the lifting rope 20. This history can be further evaluated by the evaluation unit 40 as part of the rope report. Furthermore, inspection runs for analyzing the lifting rope 20 can be omitted. This eliminates downtime during which the lifting system 10 is unavailable, ensuring that the lifting system 10 remains continuously available and that evaluation and analysis of the lifting system 10 via the generated reference characteristics are always possible.

[0078] Due to the slow changes in the lifting cable 20 and its deterioration through wire breaks, the stored reference characteristics form the epigenetic fingerprint. The collection of the stored reference characteristics 100, 125 offers a good opportunity for the non-destructive analysis of the lifting cable 20 and a way to predict the number of wire breaks to be expected at specific locations of the lifting cable 20 within a predefined period. In particular, advanced algorithms, especially within the framework of artificial intelligence, can be used to generate a prediction of wire breaks at specific cable positions p1(I) based on the reference characteristics stored in data memory 35.

[0079] Furthermore, a quasi two-factor identification of the rope position p1(I) of the respective assigned second sensor signal can be enabled regularly, routinely, cyclically, or at specific times during the use of the lifting system 10.

[0080] In addition to pattern recognition, as performed in the tenth process step 350, the evaluation unit 40 can also use the second sensor unit 75 and the second speed signal to check whether the first rope position p1(I) determined for the second sensor signal is plausible.

[0081] The pattern recognition and the optionally employed time-warping algorithm further offer the advantage of quasi-auto-calibration of the control unit 15, ensuring that the respective first rope position p1(I) of the second sensor signal can be reliably determined even with further elongation of the lifting rope 20. In particular, it has been shown that the combination of pattern recognition and time-warping algorithm can enable reliable detection of the respective assigned rope section of at least 98% locally and at least 99% globally with respect to the entire rope length of the lifting rope 20.

[0082] The control unit 15 can also be configured to provide a report on the current reference characteristic at the data interface 45 at regular intervals, which allows a prediction to be generated from the current rope condition of the lifting rope 20.

[0083] Because the historical data of the epigenetic fingerprint of the lifting rope 20 are still stored in the data storage device 35, a basis is provided upon which detailed information can be made available to a rope inspector throughout the lifespan of the lifting rope 20, based on the numerous stored reference characteristics. This allows, for example, trend graph projections or comparisons of local areas with wire breaks to be determined and viewed based on the numerous reference characteristics. This detailed information offers an additional means of providing a reliable prediction of the failure of the lifting rope 20.The rope inspector can better assess the lifting rope 20 locally based on the reference characteristics and can, if necessary, visually check the critical points of the lifting rope 20 where, according to the most recent reference characteristics, numerous wire breaks are likely to be present.

[0084] FIG 8 Figure 1 shows a schematic representation of a lifting system 10 according to a second embodiment. FIG 9 shows a perspective view of the sensor device 25 of the in FIG 8 Lifting system shown 10.

[0085] The in FIG 8 The second embodiment of the lifting system 10 shown essentially corresponds to the one shown in FIGN 1 , 2A und 2B the first embodiment of the lifting system 10 shown. The following refers exclusively to the differences of the one shown. FIG 8 lifting system 10 shown compared to the one in FIGN 1 and 2A, 2B The lifting system shown, number 10, was received.

[0086] In contrast to the FIGN 1 and 2A, 2B , in which the rolling element 80 is designed as a speedometer wheel 81, is the one in the FIGN 8 und 9 The shown uncoiling element 80 is designed as a cable drum 82. In the second embodiment, the speedometer wheel 81 is omitted. The speed sensor 90 is, for example, arranged on the uncoiling element 80 designed as a cable drum 82. The lifting cable 20 has a distance a between the contact point 85 on the cable drum 82 and the first sensor unit 70.

[0087] This within the framework of FIG 3 The described procedure can also be used for the in FIGN 8 und 9 The lifting system 10 shown is used, however, in FIGN 8 und 9In the third process step 315, during the winding and / or unwinding of the lifting rope 20, the first speed and / or the second speed of the lifting rope 20 is determined by the speed sensor 90 on the rope drum 82. It is particularly advantageous if the lifting rope 20 is wound onto the rope drum 82 in a single layer. Reference symbol list

[0088] 10 Lifting system 15 Control unit 20 Lifting rope 25 Sensor device 30 Lifting device 31 Beam device 33 Crane bridge 35 Data storage 40 Evaluation device 45 Data interface 50 First data connection 55 Second data connection 60 Third data connection 65 Guide roller arrangement 70 First sensor unit 75 Second sensor unit 80 Uncoiling element 81 Tachometer wheel 82 Rope drum 85 Attachment point 90 Speed ​​sensor 95 Start point 100 First reference characteristic 105 End 110 Rope section 111 Rope section start point 112 Rope section end point 115 Rope area 116 Subsection 120 Second signal path 125 Second reference characteristic 305 first process step 310 second process step 315 third process step 320 fourth process step 325 fifth process step 330 sixth process step 335 seventh process step 340 eighth process step 345 ninth process step 350 tenth process step 355 eleventh process step 360 twelfth process step aDistance DStropping flux change p1(I)first rope position p2(I)second rope position

Claims

1. Method for ascertaining a cable condition of a lifting cable (20) of a lifting system (10), - wherein a sensor apparatus (25) comprising at least a first sensor unit (70), a data memory (35), and a lifting cable (20) of the lifting system (10) are provided, - wherein the lifting cable (20) is moved past the first sensor unit (70) over an available cable length, - wherein the first sensor unit (70) generates a first sensor signal, which characterizes an interaction between the first sensor unit (70) and the lifting cable (20) that is moved past the first sensor unit (70), depending on a first cable position (p1(I)) of the lifting cable (20), - wherein a first signal profile of the first sensor signal is ascertained as a first reference characteristic (100) of the lifting cable (20) depending on the first cable position (p1(I)), and stored in the data memory (35), - wherein a cable section (110) of the lifting cable (20), which is shorter than or equal to the available cable length, is moved past the first sensor unit (70) after the first reference characteristic (100) of the lifting cable (20) has been ascertained, - wherein the first sensor unit (70) generates a second sensor signal, which characterizes an interaction between the first sensor unit (70) and the cable section (110) that is moved past the first sensor unit (70), depending on a second cable position (p2(I)) of the lifting cable (20), - wherein a second signal profile (120) of the second sensor signal is ascertained depending on the second cable position (p2(I)), characterized in that the second signal profile (120) of the second sensor signal is assigned to a subsection (116) of the first reference characteristic (100), - wherein the subsection (116) of the first reference characteristic (100) that is assigned to the second signal profile (120) is updated by the second signal profile (120) of the second sensor signal, - wherein the updated reference characteristic is stored as a second reference characteristic (125) in the data memory (35).

2. Method according to Claim 1, - wherein the sensor apparatus (25) has a second sensor unit (75) that is arranged so as to be spaced apart from the first sensor unit (70) and rests against the lifting cable (20), - wherein the second sensor unit (75) provides an item of information concerning a first running direction of the lifting cable (20) that is guided past the second sensor unit (75) over the available cable length when ascertaining the first reference characteristic (100), - wherein the second sensor unit (75) provides an item of information concerning a second running direction of the cable section (110) of the lifting cable (20) that is guided past the second sensor unit (75), - wherein, depending on the second running direction of the cable section (110), the second sensor signal is further processed in such a way that the first reference characteristic (100) and the second signal profile (120) are ascertained with the same running direction.

3. Method according to Claim 2, - wherein the second sensor unit (75) has a speed sensor (90), - wherein, when the lifting cable (20) moves over the available cable length, the speed sensor (90) provides a first speed signal corresponding to a first speed of the lifting cable (20) that is guided past the first sensor unit (70), - wherein, when the lifting cable (20) moves, the speed sensor (90) provides a second speed signal corresponding to a second speed of the cable section (110) that is guided past the first sensor unit (70).

4. Method according to Claim 3, - wherein the second sensor unit (75) has a rolling element (80) coupled to the speed sensor (90), - wherein the rolling element (80) rests against the lifting cable (20), - wherein, when the lifting cable (20) moves, the rolling element (80) rolls against the lifting cable (20) and the speed sensor (90) provides the first speed signal or the second speed signal, - wherein the first running direction is determined on the basis of the first speed signal and the second running direction is determined on the basis of the second speed signal.

5. Method according to Claim 3 or Claim 4, - wherein the second sensor unit (75) is arranged at a predefined distance from the first sensor unit (70), - wherein the detection of the lifting cable (20) by the first sensor unit (70) is started at a starting point (95), - wherein the first cable position (p1(I)) is ascertained based on the starting point (95) depending on the first speed signal.

6. Method according to one of Claims 3 to 5, - wherein the second speed at the second cable position (p2(I)) is compared with a predefined minimum speed, - wherein, when the minimum speed is exceeded by the second speed at the second cable position (p2(I)), the second sensor signal is taken into account for ascertaining the second signal profile (120), - wherein, in particular when the minimum speed is fallen below by the second speed at the second cable position (p2(1)), the second sensor signal is not taken into account for ascertaining the second signal profile (120).

7. Method according to one of the preceding claims, - wherein the second signal profile (120) of the sensor signal is assigned to the first reference characteristic (100) by means of a pattern recognition, in particular a cross-correlation and / or a time warping algorithm, in particular a dynamic-time-warping algorithm, and / or a self-learning algorithm.

8. Method according to one of the preceding claims, - wherein the first reference characteristic (100) is connected to a first item of temporal information relating to the time of capture of the first sensor signal and is stored with the first item of temporal information, - wherein the second reference characteristic (125) is connected to, and stored with, a second item of temporal information relating to the time of capture of the second sensor signal.

9. Method according to one of the preceding claims, - wherein the second reference characteristic (125) is evaluated on the basis of the first reference characteristic (100), - wherein a condition of the lifting cable (20) is ascertained and output on the basis of a result of the evaluation.

10. Method according to one of the preceding claims, - wherein the first sensor signal and / or the second sensor signal are / is smoothed and / or pre-filtered before the first sensor signal and / or the second sensor signal are / is evaluated, - wherein a Fast Fourier Transform and / or a wavelet transform, in particular a direct wavelet transform, and / or a low-pass filter are / is in particular applied for the filtering, - and / or wherein the first sensor signal and / or the second sensor signal are / is compared with a predefined minimum threshold value, - wherein the first signal profile is ascertained on the basis of the first sensor signal, which exceeds the predefined minimum threshold value, - wherein the second signal profile is ascertained on the basis of the second sensor signal, which exceeds the predefined minimum threshold value.

11. Method according to one of the preceding claims, - wherein the cable section (110) for ascertaining the second signal profile (120) is ascertained after a predefined time interval has elapsed, for example from 1 hour to 12 hours, inclusive, or after a predefined number of lifting cycles has been carried out.

12. Method according to one of the preceding claims, - wherein the available cable length is moved past the first sensor unit (70) at at least a predefined minimum speed, - wherein the minimum speed is preferably at least 0.1 m / s, inclusive, in particular at least 0.2 m / s, inclusive.

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