Method for determining a cable state of a hoisting cable of a hoisting system and hoisting system for a large industrial installation

Abstract

The invention relates to a method for determining a cable state of a hoisting cable of a hoisting system (10) and to a hoisting system (10), wherein a sensor device (25), a control unit (15) having an evaluation device (40), a data interface (45) connected to the evaluation device (40) for data exchange, a data memory (35) connected to the evaluation device (40) for data exchange, and a hoisting cable (20) having a plurality of wires are provided, wherein at least one pattern set of a plurality of pattern signal profiles is stored in the data memory (35), wherein each pattern signal profile is assigned information about a wire break (B), wherein at least one cable section (110) of the hoisting cable (20) is moved past the sensor device (25), wherein the sensor device (25) provides to the evaluation device (40) a second sensor signal which characterises an interaction between the sensor device (25) and the hoisting cable (20) moved past the sensor device (25), wherein the evaluation device (40) determines a second signal profile (120) over the cable section (110), wherein the evaluation device (40) determines a wire break (B) in the cable section (110) by assigning a pattern signal profile of the pattern set which matches the second signal profile (120).

Description

[0001] Description

[0002] Method for determining the condition of a lifting rope of a lifting system and lifting system for a large industrial plant

[0003] The invention relates to a method for determining a rope condition of a lifting rope of a lifting system according to patent claim 1 and a lifting system according to patent claim 15.

[0004] EP 4 065 498 A1 discloses an arrangement for monitoring an elevator having an elevator rope. The elevator rope is guided past an inductive sensor positioned so that a magnetic field generated by the inductive sensor, which extends at least partially across the elevator rope, is evaluated by a control device.

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

[0006] This object is achieved by means of a method according to claim 1 and a lifting system according to claim 15. Advantageous embodiments are specified in the dependent claims.

[0007] An improved method for determining the condition of a hoisting rope of a hoisting system can be provided by providing a sensor device, a control unit with an evaluation device, a data interface connected to the evaluation device for data transmission, a data memory connected to the evaluation device for data transmission, and a hoisting rope with a plurality of wires. At least one sample set of several sample signal waveforms is stored in the data memory. Information about a wire break is associated with each sample signal waveform. The data interface is connected to the sensor device for data transmission, with at least one section of the hoisting rope being moved past the sensor device.The sensor device provides a second sensor signal, which characterizes an interaction between the sensor device and the hoisting rope moving past the sensor device, via the data interface of the evaluation device. The evaluation device determines a second signal profile of the second sensor signal over the rope section. The evaluation device determines a wire break in the rope section moving past the sensor device by assigning a sample signal profile from the sample set that matches the second signal profile.

[0008] The information about the wire break can be designed such that the information has an assignment to a wire break or a multiple wire break and / or an assignment to a cable defect class. Furthermore, the sample signal curve can, for example, have information about at least one triangular curve and / or another characteristic value such as a density of zero crossings (a zero crossing is characterized by a change in the sign of the signal) and / or a number of zero crossings, a minimum and / or maximum peak value and / or a sequence of a change in sign of a signal curve section. The sample signal curve can, for example, be stored in the data memory in tabular form and / or as a mathematical function, for example as a mathematical series and / or spline and / or polynomial.

[0009] This design of the method has the advantage that wire breaks and multiple wire breaks, as well as closely spaced wire breaks, can be reliably detected by the evaluation device.

[0010] Reliable detection can be improved in particular by creating the sample signal curves in advance, for example, and analyzing and evaluating them in advance, so that both the detection rate and the defined assignment are increased, especially in the case of multiple wire breaks.

[0011] In a further embodiment, at least one first reference characteristic of the hoisting rope is stored in the data memory, wherein the first reference characteristic comprises information of a first signal curve of a substantially new hoisting rope plotted against a first rope position. The new hoisting rope is characterized in that it is free of wire breaks and / or has only a very few wire breaks, for example, less than 1 / 10 of the maximum number of wire breaks permitted until the rope is ready for discard. The evaluation device assigns the determined second signal curve to a reference section of the first reference characteristic, wherein the evaluation device determines a first rope position of the determined wire break based on the first reference characteristic.This configuration has the advantage that the second signal profile can be determined during operation of the lifting system without the need to additionally move the lifting rope to a reference point for evaluation of the lifting rope. In a further embodiment, the evaluation device, in particular, can have a machine-learning algorithm. The lifting rope can be evaluated particularly well by training the evaluation device using a sample set of sample signal profiles stored in the data memory, with the trained evaluation device evaluating the shape of the deviation range based on the training.

[0012] In addition, the evaluation device can apply a pattern recognition, in particular a time warping algorithm, in particular a dynamic time warping algorithm and / or fast Fourier transformation and / or a wavelet transformation, in particular a direct wavelet transformation, in order to assign the pattern signal curve to the second signal curve and / or the second signal curve of the sensor signal to the first reference characteristic.

[0013] The evaluation device executes a self-learning algorithm to detect wire breaks. The self-learning algorithm is preferably a one-class support vector machine algorithm, an isolation forest algorithm, a decision tree algorithm, and / or a histogram-based outlier score algorithm. These algorithms have proven particularly advantageous for the evaluation device, allowing a particularly high detection rate for wire breaks in the hoisting rope to be achieved.

[0014] In a further embodiment, a predefined reference length is stored in the data memory, wherein the evaluation device determines a number of wire breaks per reference length in the second signal curve based on the predefined reference length. The evaluation device compares the determined number of wire breaks per reference length with a predefined maximum threshold value. If the predefined maximum threshold value is exceeded, the evaluation device provides information about the discard status of the lifting rope at the data interface. This embodiment has the advantage that the discard status can be automatically detected within the framework of the method without further evaluation by a rope inspector.

[0015] In a further embodiment, a predefined reference length is stored in the data memory, wherein the evaluation device determines a number of wire breaks per reference length in the second signal curve on the basis of the predefined reference length, wherein the evaluation device determines a maximum of the determined number of wire breaks per reference length, preferably for the evaluated lifting rope, wherein the evaluation device determines a minimum distance between the maximum and a predefined maximum threshold value, wherein, on the basis of the minimum distance, the evaluation device provides warning information and / or a prediction about an impending discard date of the lifting rope at the data interface.This design has the advantage that it enables timely planning of a downtime of the lifting system for replacing the lifting rope and / or timely ordering and organization of a new lifting rope and, based on the forecast, the time horizon can also be given when the rope is due to be discarded.

[0016] In a further embodiment, at least one threshold characteristic with at least a plurality of different threshold values ​​is stored in the data memory. The evaluation device determines a deviation between the second signal curve and the first reference characteristic. The evaluation device compares the deviation with the threshold characteristic. If at least one of the threshold values ​​of the threshold characteristic is exceeded, the evaluation device verifies at least the information about the wire break. This allows the detection rate of the respective wire break to be further increased or the reliability of the detection to be further increased.

[0017] In a further embodiment, the evaluation device determines an envelope based on the first reference characteristic, and the evaluation device determines the threshold characteristic based on the envelope. This allows the threshold values ​​of the threshold characteristic, which are configured, for example, as stepped threshold values, to be specifically adapted to the respective lifting rope.

[0018] In a further embodiment, the first reference characteristic is determined at the beginning of use of the hoisting rope by moving the hoisting rope past the sensor device, preferably in an initialization process, preferably over its entire possible length, for example defined by the usage or operating area associated with the respective crane. The sensor device generates a first sensor signal, which characterizes an interaction between the sensor device and the hoisting rope moved past the sensor device, as a function of the first rope position of the hoisting rope and provides it to the evaluation device via the data interface. The evaluation device determines a first signal profile of the sensor signal over the first rope position. The first signal profile is stored in the data memory as the first reference characteristic.

[0019] In a further embodiment, a running direction of the cable section of the hoisting cable guided past the sensor device is determined, wherein the second sensor signal is further processed depending on the running direction of the cable section such that the first reference characteristic and the second signal curve are determined with the same running direction. Preferably, in particular, the second signal curve is inverted on the basis of the second cable position such that the first reference characteristic and the second signal curve have the same running direction. This can be done, for example, by mirroring the entire second signal curve at a reversal point between a starting point and an end point of the second signal curve of the running direction. This achieves a particularly high level of agreement with the same signal curve. Furthermore, the recognition rate is further improved.

[0020] In a further embodiment, the second signal waveform forms a second reference characteristic, which is determined chronologically after the first reference characteristic. Additionally or alternatively, the evaluation device determines matrix profiles for the first reference characteristic and the first signal waveform, wherein the evaluation device determines similarities and / or matches between the first reference characteristic and the first signal waveform on the basis of the determined matrix profiles. This embodiment has the advantage that the respective matches can serve as reference points or as orientation points for the pattern recognition method, so that the evaluation device can orient itself particularly well in its position to the first reference characteristic.can easily detect abnormalities, in particular deviations in the respective signal curve between the first reference characteristic and the first signal curve, and can evaluate the respective deviations particularly well in order to detect wire breaks.

[0021] In a further embodiment, the first sensor signal and / or the second sensor signal is smoothed and / or pre-filtered before the first sensor signal and / or the second sensor signal is evaluated, wherein in particular a Fast Fourier Transformation and / or a Wavelet Transformation, in particular a Direct Wavelet Transformation, and / or a low-pass filter is applied for filtering, and / or wherein the first sensor signal and / or the second sensor signal is compared with a predefined minimum threshold value, wherein the first signal profile is determined on the basis of the first sensor signal which exceeds the predefined minimum threshold value, wherein the second signal profile is determined on the basis of the second sensor signal which exceeds the predefined minimum threshold value.

[0022] It is also advantageous if the lifting system lifts a load of at least 201 to 10,001 lbs, with the second cable section moving past the sensor device when lifting or lowering the load. This eliminates the need for additional measurement runs that would interrupt regular production operations. Furthermore, the second sensor signal is enhanced by stretching the lifting cable under load.

[0023] An improved lifting system can be provided in that the lifting system is designed in particular for a large-scale industrial plant, in particular a rolling mill and / or a continuous casting machine, wherein the lifting system is configured to carry out the method described above. Furthermore, the lifting system has at least one lifting rope, wherein the lifting system has a lifting rope load capacity of at least 20 t, wherein the lifting system is further preferably configured to lift and / or lower loads.

[0024] The invention is explained in more detail below with reference to figures:

[0025] FIG 1 is a schematic representation of a lifting system;

[0026] FIGS. 2A, 2B show the sensor device from different perspective views on the lifting rope;

[0027] FIG 3 is a flow chart of a method for operating the device shown in FIGS. 1 and

[0028] 2A, 2B shown lifting system;

[0029] FIG 4 shows a schematic first diagram of a first reference characteristic;

[0030] FIG 5 shows a schematic second diagram of a second signal curve of a second sensor signal over a second cable position;

[0031] FIGS. 6A to 6F each show an exemplary sample signal waveform of a sample set;

[0032] FIG 7 shows a third schematic diagram of the first reference characteristic with the associated second signal curve; and

[0033] FIG 8 an evaluation of wire breaks plotted over the first rope position.

[0034] FIG 1 shows a schematic representation of a lifting system 10. The lifting system 10 is designed, for example, as a crane, in particular, for example, as a gantry crane. The lifting system 10 can, for example, be designed to be mounted in a large-scale industrial production facility, for example in a building of a continuous casting machine or a cast-rolling composite plant or another building used for steel or metal production, in order to lift heavy objects, in particular, for example, ladles and / or steel slabs and / or steel coils, by means of a lifting rope 20 of the lifting system 10. The lifting system 10, in particular the lifting rope 20, is subject to high loads and is subject to corresponding wear and aging. The lifting rope 20 may only be used as long as it is not worn out and ready for disposal.

[0035] In order to determine the wear and aging, the lifting system 10 has, in addition to the lifting rope 20, a control unit 15, a sensor device 25 and a lifting device 30 and a carrying device 31.

[0036] The control unit 15 has a data memory 35, an evaluation device 40, and a data interface 45. The data interface 45 is connected to the evaluation device 40 via a first data connection 50. Furthermore, the evaluation device 40 is connected to the data memory 35 via a second data connection 55. The data interface 45, in turn, is connected to the sensor device 25 via a third data connection 60.

[0037] The support device 31 can, for example, comprise a trolley that is arranged to be movable along a crane bridge 33 of the lifting system 10. The lifting device 30 can, for example, comprise a drive unit that is arranged, for example, on the trolley. The drive unit is designed to wind up or unwind the lifting cable 20 and to lift or lower loads using the lifting cable 20 or the lifting gear arranged thereon, for example.

[0038] During operation of the lifting system 10, the lifting rope 20 is frequently moved. The lifting rope 20 has a plurality of stranded wires. The wires can be made, for example, of ferromagnetic and / or austenitic steel. Over the service life of the lifting rope 20, the lifting rope 20 wears, firstly, due to the loads lifted by means of the lifting rope 20 and the associated elongation of the lifting rope, and secondly, in particular, due to the bending and / or re-bending of the lifting rope 20, which occurs, for example, during winding and unwinding of the lifting rope 20. In this case, one or more wires can break at a different or at the same first rope position p1 (I). If the wire breaks B occur frequently over a predefined length, the lifting rope 20 is considered worn and must be replaced to prevent accidental tearing of the lifting rope 20, for example under heavy loads, or accidental further breakage of the wires.

[0039] The sensor device 25 is mechanically connected, for example, to the trolley and arranged on the hoist cable 20. The sensor device 25 preferably remains on the trolley during operation of the lifting system 10 and is not disassembled unless repair or maintenance is necessary that would require disassembly. The hoist cable 20 is guided through the sensor device 25.

[0040] FIGS. 2A and 2B show the sensor device 25 from different perspective views on the lifting rope 20.

[0041] The sensor device 25 comprises a guide roller assembly 65, a first sensor unit 70, and at least one second sensor unit 75. The guide roller assembly 65 is designed to guide the lifting cable 20 in the sensor device 25 and to establish a predefined cable guide distance between the first sensor unit 70 and the lifting cable 20.

[0042] 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 cable 20. The magnetic field sensor is designed to provide a first sensor signal corresponding to the lifting cable 20 guided through the magnetic field of the magnetic field generator.

[0043] The second sensor unit 75 can, for example, have a speedometer wheel 80 and a speed sensor 90, wherein the speedometer wheel 80 rests against the lifting cable 20 at least at a contact point 85. When the lifting cable 20 is moved, the speedometer wheel 80 rolls on the lifting cable 20. The speed sensor detects a speed of the lifting cable 20 guided past the second sensor unit 75. It should be noted that the speed of the lifting cable 20 can be measured contactlessly or at a position other than that shown in FIGS. 2A / 2B. For example, it is also possible to determine the speed on a cable drum of the lifting system 10 as a replacement for the speedometer wheel 80. The contact point 85 is arranged at a distance a from the first sensor unit 70. FIG. 3 shows a flowchart of a method for operating the lifting system 10 shown in FIGS. 1 and 2A, 2B. FIG. 4 shows a schematic first diagram of a first reference characteristic 100.FIG. 5 shows a schematic second diagram of a second signal profile 120 of a second sensor signal over a second cable position p2(I). FIGS. 6A to 6F each show an exemplary sample signal profile of the sample set. FIG. 7 shows a third schematic diagram of the first reference characteristic 100 with the associated second signal profile 120. FIG. 8 shows an evaluation of wire breaks B plotted over the first cable position p1(I).

[0044] The method described below is preferably repeated over the entire service life of the lifting rope 20, preferably at regular intervals. For this purpose, the lifting rope 20 is preferably mounted on the lifting device 30 at the beginning of its service life in a preferably new or barely worn condition.

[0045] Before the start of the method, a minimum speed, a predefined maximum threshold value M related to a reference length, and the sample set of sample signal waveforms are stored in the data memory 35 (see FIGS. 6A to 6F). Each sample signal waveform of the sample set is assigned a type of wire break or a multiple wire break or a rope defect class (label). Exemplary sample signal waveforms are shown in FIGS. 6A to 6F. Each sample signal waveform has a different characteristic and represents a different wire break B and / or multiple wire break formed from multiple wire breaks B essentially at the same first rope position p1 (I) and / or a different rope defect class. The characteristic is primarily determined by the shape of the sample signal waveform and / or its features.Furthermore, the sample signal waveform can, for example, contain information about at least one triangular waveform and / or another characteristic value, such as a density of zero crossings (a zero crossing is characterized by a change in the signal's sign) and / or a number of zero crossings, a minimum and / or maximum peak value, and / or a sequence of sign changes of a signal waveform section. The sample signal waveform can, for example, be stored in the data memory 35 in tabular form and / or as a mathematical function, for example as a mathematical series and / or spline and / or polynomial.

[0046] For example, a first sample signal waveform shown in FIG. 6A shows a double wire break located close to another single wire break. FIG. 6B shows a 12-wire break, which correlates with a discard point of the hoist rope 20. FIG. 6C, for example, shows a single wire break with a nearby quadruple wire break. FIG. 6D, for example, shows a 6-wire break. FIG. 6E, for example, shows a single wire break. FIG. 6F shows a quadruple wire break (with negative amplitude).

[0047] In a first method step 305, the lifting rope 20 is mounted in the lifting system 10 essentially in a new or barely worn condition, and the sensor device 25 is permanently mounted on the lifting rope 20, so that during each lifting or lowering operation or during each movement of the lifting rope 20 by the lifting device 30, the lifting rope 20 is guided past the sensor device 25.

[0048] In a second method step 310, for example, the lifting rope 20 is completely unwound or completely wound up once. For this purpose, for example, a crane hook of the lifting system 10 can be completely raised and moved to the lowest point within the usable range of the lifting system 10. Once the lifting rope 20 is wound up or completely unwound, a starting point 95 of the lifting rope 20 is thereby defined. The starting point 95 serves as a reference point on the lifting rope 20. The first rope position p1 (I) can be referenced and related to the starting point 95.

[0049] In a third method step 315, the lifting cable 20 is guided past the sensor device 25 at the minimum speed in a first direction of travel. For example, the minimum speed can be at least 0.1 m / s, in particular at least 0.2 m / s. However, the speed at which the lifting cable is moved should not exceed 50 m / s.

[0050] The sensor device 25 is activated in the third method step 315. For example, the magnetic field generator provides the magnetic field. The magnetic field of the magnetic field generator acts on the lifting cable 20 and the individual wires of the lifting cable 20. The ferromagnetic and / or austenitic material of the lifting cable 20 changes the magnetic field flux. In the 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 device 40. The evaluation device 40 detects the first sensor signal.

[0051] The control unit 15 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 Transformation and / or a Wavelet Transformation, in particular a Direct Wavelet Transformation, and / or a low-pass filter or averager is used for filtering.

[0052] In the third method step 315, the speedometer wheel 80 rolls on the hoisting cable 20 from the starting point 95, and the speed sensor 90 provides, for example, information about the speed of the hoisting cable 20 as part of a first speedometer signal via the third data connection of the data interface 45 and the first data connection 50 of the evaluation device 40. The evaluation device 40 detects the second sensor signal.

[0053] The control unit 15 can filter and / or smooth the first speedometer signal before further processing, with averaging being used, in particular, for smoothing. The control unit 15 can have an additional second filter for filtering.

[0054] The lifting rope 20 is wound up or unwound over an available rope length starting from the starting point up to a maximum movable end 105 and guided past the sensor device 25.

[0055] In a fourth method step 320 following the third method step 315, the evaluation device 40 determines a first cable position p1 (I) associated with the first sensor signal relative to the starting point 95 on the basis of the distance a between the second sensor unit 75 and the first sensor unit 70 and the speed information of the first tachometer signal via the hoist cable 20. In other words, a first sensor signal is determined at a distance of a specific length from the starting point 95 at the respectively associated first cable position p1 (I).

[0056] In a fifth method step 325 following the fourth method step 320 (see FIG. 4), the evaluation device 40 determines a first signal profile of the first sensor signal for the respectively assigned first cable position p1 (I) between the start position 95 and the end 105. The evaluation device 40 stores the first signal profile in the data memory 35 as a first reference characteristic 100. It is further assumed that the new lifting cable 20 is essentially free of wire breaks B, or has only very few - e.g., fewer than 10 - wire breaks over the entire detectable cable length.

[0057] Furthermore, the evaluation device 40 preferably stores a first time information item associated with the first reference characteristic 100, which essentially corresponds to the detection time of the first sensor signal. The first reference characteristic 100 forms a first fingerprint of the lifting cable 20, which is unique to the respective lifting cable 20.

[0058] The first sensor signal correlates with a stray flux D of a magnetic flux in the hoisting rope 20. The 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 B at the assigned first rope position p1 (I). The first reference characteristic 100 (cf. FIG. 4), for example, has a jagged first profile of the first sensor signal over the first rope position p1 (I). The greater the amplitude of the first sensor signal at an assigned first rope position p1 (I), the stronger / more severe the stray flux D changes at the respectively assigned first rope position p1 (I). Therefore, if the first sensor signal has a high amplitude, the hoisting rope 20 has one or more wire breaks B at the respectively assigned first rope position p1 (I).

[0059] In addition, the evaluation device 40 can determine the threshold characteristic with at least the first threshold based on the first reference characteristic 100. Preferably, the evaluation device 40 determines an envelope around the first reference characteristic 100 based on the first reference characteristic 100. Based on the envelope, the evaluation device 40 determines the threshold characteristic. At least the first threshold and preferably the additional threshold values ​​further away from the first threshold can, for example, each have a predefined minimum distance from the envelope of the first reference characteristic 100.

[0060] The first to fifth method steps 305 to 325 represent an initialization process of the lifting rope 20. The initialization process can be performed when the lifting rope 20 is installed in the lifting system 10.

[0061] After the initialization process, the lifting system 10 can be used as intended to lift or lower loads using the lifting rope 20. The method steps described below are carried out cyclically at regular intervals during the use of the lifting rope 20. It is particularly advantageous if the method steps described below are carried out, for example, at a shift change, for example every eight hours. Of course, a different time interval is also possible. The following method steps are started automatically, preferably by the control unit 15. At the beginning of the following method steps, the lifting rope 20 does not have to be completely wound or unwound, but can also be in an intermediate position at the sensor device 25. A cable section 110 of the lifting rope 20 is guided past the sensor device 25 at the minimum speed.The rope length 110 can be between the starting point 95 and the end 105 of the lifting rope 20. The rope length 110 can be shorter than the maximum length of the lifting rope 20 between the starting point 95 and the end 105 of the lifting rope 20.

[0062] The cable section 110 can also extend completely between the starting point 95 and the end 105 of the lifting cable 20, so that a maximum available length of the lifting cable 20 is guided past the sensor device 25.

[0063] Analogous to the third method step 315, in the sixth method step 330, the first sensor unit 70 provides a second sensor signal based on the interaction between the first sensor unit 70 and the cable section 110 of the hoisting cable 20 that is guided past the sensor device 25. The second sensor signal characterizes an interaction between the sensor device 25 and the hoisting cable 20 that is moved past the sensor device 25. The first sensor unit 70 provides the second sensor signal to the evaluation device 40 via the data interface 45.

[0064] 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 device 40. The evaluation device 40 detects the second sensor signal.

[0065] The minimum speed is an important prerequisite for the second sensor signal to have plausible and usable values ​​for the leakage flux D over the entire signal curve and thus to be further processed by the evaluation device 40.

[0066] The second sensor signal correlates with the leakage flux D of the magnetic flux on the cable section 110 of the lifting cable 20. The leakage flux D of the second sensor signal corresponds to a local change in the magnetic flux, for example due to a wire break B or a multiple wire break B at a second cable position p2(l).

[0067] In the sixth method step 330, the speedometer wheel 80 rolls on the hoisting cable 20 at a distance a offset from the first sensor unit 70, and the speed sensor 90 provides, as part of a second speedometer signal, for example, information about the speed of the hoisting cable 20 via the third data connection 60 to the data interface 45 and via the second data connection 55 to the evaluation device 40. The evaluation device 40 detects the second speedometer signal. In a seventh method step 335 following the sixth method step 330, the evaluation device 40 determines the second cable position p2(l) within the cable section 110 for the respectively detected second sensor signal based on the distance a and the speed information of the second speedometer signal.

[0068] In an eighth method step 340 following the seventh method step 335, the evaluation device 40 compares the speed information of the second speedometer signal with the minimum speed stored in the data memory 35. If the minimum speed is exceeded, the further method steps are discontinued, since the leakage flux D detected at the second signal position p2(l) is deemed unusable for further evaluation. If the minimum speed is exceeded, the evaluation device 40 proceeds to a ninth method step 345.

[0069] In the ninth method step 345, the evaluation device 40 determines a second signal profile 120 of the second sensor signal over the cable section 110 (see FIG. 5). In particular, the second signal profile 120 is assigned to the respectively determined second cable position p2(l) within the cable section 110. The second cable position p2(l) extends, for example, between a starting point of the detection of the leakage flux D with the minimum speed up to an end point of the detection of the leakage flux D with the minimum speed. The starting point can be different from the starting point 95 and / or the end point can be different from the end 105.

[0070] Furthermore, in the ninth method step 345, the evaluation device 40 can check a second running direction based on the second tachometer signal with which the cable section 110 is guided past the sensor device 25 in the sixth method step 330. If the second running direction corresponds to the first running direction of the first reference characteristic 100, the evaluation device 40 continues with the determined second signal curve 120.If the second running direction is opposite to the first running direction of the first reference characteristic 100, the evaluation device 40 inverts the second signal curve 120 by inverting the determined second cable position p2(l) with reference to the starting point and the end point, for example by mirroring at a reversal point located between the starting point and the end point, for example centrally, and accordingly updates the second signal curve 120 of the sensor signals via the respectively assigned second cable position p2(l) within the cable section 110.

[0071] In a tenth method step 350 following the ninth method step 345, the evaluation device 40 compares the second signal profile 120 of the second sensor signals over the cable section 110 with the first reference characteristic 100 and assigns the second signal profile 120 to a reference section 115 of the first reference characteristic 100, for example by means of pattern recognition and / or Fast Fourier Transformation and / or a Wavelet Transformation, in particular a Direct Wavelet Transformation (cf. FIG. 7).

[0072] For example, the evaluation device 40 can determine a matrix profile for each of the first reference characteristic 100 and the second signal waveform 120. The matrix profile can be a vector that represents a normalized Euclidean distance between a subsequence of the first reference characteristic 100 and the second signal waveform 120. For example, the first reference characteristic 100 can represent a time- and location-related series (x1), with the second signal waveform 120 representing a nearest neighbor of a series (x2). The evaluation device 40 can, for example, break down both the first reference characteristic 100 and the second signal waveform 120 into subsequences and select them as characteristic patterns for the time- or location-related series.In particular, it is advantageous if the evaluation device 40 selects intervals for the first reference characteristic 100 and / or the second signal curve in which the first reference characteristic 100 has deflections in its amplitude and / or signal shape sections in its curve which indicate one or more wire breaks B.

[0073] By means of the matrix profiles, the evaluation device 40 can efficiently determine a distance within a selected subsequence of the first reference characteristic 100 to each subsequence of the second signal curve 120 and determine the smallest distance within the matrix.

[0074] Using the matrix profiles, the evaluation device 40 can, for example, determine recurring patterns or motifs between the first reference characteristic 100 and the second signal profile 120. Using the recurring patterns or motifs, the evaluation device 40 can, for example, assign the second signal profile 120 to a reference section 115 of the first reference characteristic 100.

[0075] As an alternative to the use of matrix profiles, it is also possible for the evaluation device 40 to assign the second signal curve 120 to a reference section 115 of the first reference characteristic 100, preferably by means of a Fast Fourier Transformation (FFT for short) and / or preferably a Time Warping algorithm, in particular a Dynamic Time Warping algorithm. The Time Warping algorithm, in particular the Dynamic Time Warping algorithm, has the advantage that a stretching of the lifting cable 20 over time and / or an elasticity of the lifting cable 20 and / or a slippage of the tachometer wheel 80 on the lifting cable 20 can be compensated for and / or taken into account. The Fast Fourier Transformation has the advantage that it provides a very precise amplitude characteristic, which can promote local assignments between the first reference characteristic 100 and the second signal curve 120 even without the presence of wire breaks.

[0076] The dynamic time warping algorithm and / or the Fast Fourier Transformation thus provides an improved match between the second signal curve 120 and the first reference characteristic 100 within the framework of pattern recognition.

[0077] By assigning the second signal curve 120 to the reference section 115 of the first reference characteristic 100, the evaluation device 40 can reliably assign the second cable position p2(l) of the second sensor signal to the respective first cable position p1(l) of the first reference characteristic 100 on the basis of the first reference characteristic 100.

[0078] In an eleventh method step 355, the evaluation device 40 further determines at least one matching region 116 of the second signal curve 120 within the reference section 115 of the first reference characteristic 100, in which the second signal curve 120 substantially matches the first reference characteristic 100 (cf. FIG. 4).

[0079] The evaluation device 40 further determines, for example, a deviation range 117 in which the second signal curve 120 deviates from the reference section 115 of the first reference characteristic 100 (see FIG. 4). In this case, the deviation range 117 in FIG. 1 lies, for example, between two agreement ranges 116. In the deviation range 117, there is a change in the second signal curve 120 over time compared to the reference section 115 of the first reference characteristic 100, essentially at the same first cable position p1 (I). The change is greater than a predefined deviation threshold. This change results from one or more newly occurred wire breaks B at the first cable position p1 (I).If the hoisting rope 20 has been used only to a limited extent since the first reference characteristic 100 was determined, it may happen that the second signal profile 120 and the reference section 115 are essentially identical, and the evaluation device 40 does not determine a deviation range 117. It is particularly advantageous if the evaluation device 40 breaks down the deviation range 117 and / or the deviation ranges 117, in which the second signal profile 120 deviates from the first reference characteristic 100, into individual evaluation ranges 118, 119 (see FIG. 5). The breakdown can be carried out, for example, on the basis of a profile, for example in the region of a peak, for example before and after a peak. By breaking it down, the evaluation device 40 can determine the first rope position p1 (I) of the respective evaluation range 118, 119 in a defined manner.

[0080] In a twelfth method step 360, the evaluation device 40 compares the at least one evaluation range 118, 119 with the sample set of sample signal waveforms. In this case, each of the evaluation ranges 118, 119 of the second signal waveform 120 is preferably compared and / or evaluated with a plurality of sample signal waveforms of the sample set (cf. FIGS. 6A to 6F), for example, in terms of its shape.

[0081] The evaluation device 40 can, for example, apply a pattern comparison method. Furthermore, the evaluation device 40 selects, for example, the sample signal waveform from the sample set that exhibits the greatest correspondence with the respective evaluation range 118, 119 of the second signal waveform 120. As already explained, the information about a wire break B and, if applicable, a wire break number B and / or the cable defect class is stored in the data memory 35 for each sample signal waveform.

[0082] In the embodiment, the evaluation device 40 recognizes, for example, that a first evaluation region 118 corresponds to the sample signal waveform shown in FIG. 6D and a second evaluation region 119, which is arranged offset in FIG. 5 to the first evaluation region 118, corresponds essentially to the sample signal waveform shown in FIG. 6F.

[0083] In addition, the evaluation device 40 can identify the corresponding assigned wire break B based on the correspondence of the evaluation area 118, 119 with one of the sample signal curves and, via the assignment of the second signal curve 120 to the first reference characteristic 100, determine the first cable position p1 (I) assigned to the wire break B or the multiple wire breaks B based on the first reference characteristic 100 and store the respective first cable position p1 (I) for the determined wire break B in the data memory 35.

[0084] In addition, the evaluation device 40 can determine a deviation b between the second signal curve 120 and the first reference characteristic 100 at the first cable position p1 (I). The evaluation device 40 can compare the deviation b with the threshold characteristic, wherein, if at least one of the threshold values ​​of the threshold characteristic is exceeded, the evaluation device 40 verifies at least the information about the wire break B.

[0085] In a thirteenth method step 365, the evaluation device 40 can determine a number of wire breaks B per reference length, preferably across the entire updated second reference characteristic 125, based on a predefined reference length stored in the data memory 35. 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. For this purpose, the evaluation device 40, for example, sums up the wire breaks B determined within the predefined reference length.

[0086] In FIG 8, for example, the determined wire breaks B per reference length are plotted against the respectively assigned first rope position p1 (I).

[0087] In a fourteenth method step 370, which follows the thirteenth method step 365, the evaluation device 40 compares the determined number of wire breaks B per reference length with a predefined maximum threshold value M stored in the data memory 35. The predefined maximum threshold value M corresponds to the value at which the lifting rope 20 is ready for discarding in order to be subjected to the loads permitted for the lifting rope 20. The maximum threshold value M is shown in FIG. 8 by a dashed line.

[0088] In a fifteenth method step 375, the evaluation device 40 provides information about the discard readiness of the lifting rope 20 at the data interface 45 if the predefined maximum threshold value M is exceeded by the determined number of wire breaks B per reference length.

[0089] Additionally, in the thirteenth method step 365, the evaluation device 40 can determine a maximum MAX of the determined number of wire breaks B within the reference length. The maximum MAX can be smaller than the maximum threshold value M. For example, the evaluation device 40 additionally determines a minimum distance c, for example by calculating the difference, between the maximum MAX of the determined number of wire breaks B per reference length and the predefined maximum threshold value M. Based on the minimum distance c, the evaluation device 40 provides warning information or, based on the time interval between the determination of the second signal curve 120 and the first reference characteristic 100, a prediction of an impending discard date of the lifting rope 20 at the data interface 45.

[0090] It is particularly advantageous, in particular when determining and assigning the second signal curve 120 to the first reference characteristic 100 and / or when detecting the wire breaks B in the second comparison, in which the evaluation areas 118, 119 of the second signal curve 120, which do not match the first reference characteristic 100, are compared with the sample set, if the evaluation device 40 has a self-learning algorithm and carries out this.

[0091] In particular, the evaluation device 40 can preferably use a one-class support vector machine algorithm and / or an isolation forest algorithm and / or a histogram-based outlier score algorithm in order to reliably detect wire breaks B and / or multiple wire breaks B with an increasing number of deviations in the second signal curve 120 from the first reference characteristic 100.

[0092] Furthermore, during the initialization process (first to fifth method steps 305 to 325), the self-learning algorithm can also be trained with the sample signal set and, on the basis of the training, evaluate the evaluation range 118, 119 in the twelfth method step 360.

[0093] Furthermore, it is pointed out that the evaluation device 40 can combine several second signal curves 120 into a second signal curve, for example within the scope of the sixth to ninth method steps 330, 335, 340, 345.

[0094] Furthermore, it is possible to determine a second reference characteristic 125 based on the second signal waveform 120 and / or to update the first reference characteristic 100. The second reference characteristic 125 and / or a plurality of second reference characteristics 125, which are generated at a time interval after the first reference characteristic 100, can be stored together in the data memory 35.

[0095] It is also possible for the initialization process to be repeated at regular time intervals in order to generate the second reference characteristic 125 instead of the first reference characteristic 100. The second reference characteristic 125 then replaces the first reference characteristic 100 in the sixth to fifteenth method steps 330 to 375, wherein the sixth to fifteenth method steps 330 to 375 are carried out at a time interval, preferably of at least 1 hour, in particular at least 8 hours, from the determination of the second reference characteristic 125. In addition, wire breaks B already detected at a first cable position p1 (I) can be stored in the data memory 35 as additional wire break information for the first cable position p1 (I) within the framework of the second reference characteristic 125.

[0096] List of reference symbols

[0097] 10 Lifting system

[0098] 15 Control unit

[0099] 20 lifting rope

[0100] 25 Sensor device

[0101] 30 lifting device

[0102] 31 Carrying device

[0103] 33 Crane Bridge

[0104] 35 data storage

[0105] 40 Evaluation device

[0106] 45 Data interface

[0107] 50 first data connection

[0108] 55 second data connection

[0109] 60 third data connection

[0110] 65 Guide roller arrangement

[0111] 70 first sensor unit

[0112] 75 second sensor unit

[0113] 80 speedometer wheel

[0114] 85 Investment point

[0115] 90 Speed ​​sensor

[0116] 95 Starting point

[0117] 100 first reference characteristics

[0118] 105 End

[0119] 110 rope sections

[0120] 115 Reference section of the first reference characteristic

[0121] 116 Match area

[0122] 117 Deviation range

[0123] 118 first evaluation area

[0124] 119 second evaluation area

[0125] 120 second signal curve

[0126] 125 second reference characteristic 305 first process step 310 second process step 315 third process step 320 fourth process step

[0127] 325 fifth procedural step

[0128] 330 sixth process step 335 seventh process step

[0129] 340 eighth process step

[0130] 345 ninth procedural step

[0131] 350 tenth process step 355 eleventh process step

[0132] 360 twelfth procedural step

[0133] 365 thirteenth procedural step

[0134] 370 fourteenth procedural step

[0135] 375 fifteenth process step a distance b deviation

[0136] B Wire break minimum distance between the maximum and the maximum threshold

[0137] M Maximum threshold

[0138] MAX Maximum number of wire breaks within a reference length p1 (l) first rope position (referenced to the start point or the end point) p2(l) second rope position

Claims

Patent claims 1 . Method for determining a rope condition of a lifting rope (20) of a lifting system (10), - wherein a sensor device (25), a control device (15) with an evaluation device (40), a data interface (45) connected to the evaluation device (40) for data technology purposes, a data memory (35) connected to the evaluation device (40) for data technology purposes, and a lifting cable (20) with a plurality of wires are provided, - wherein at least one sample set of several sample signal waveforms is stored in the data memory (35), - each sample signal waveform being assigned information about a wire break (B), - wherein the data interface (45) is connected to the sensor device (25) for data purposes, - wherein at least one rope section (110) of the lifting rope (20) is moved past the sensor device (25), - wherein the sensor device (25) provides a second sensor signal, which characterises an interaction between the sensor device (25) and the lifting rope (20) moving past the sensor device (25), via the data interface (45) of the evaluation device (40), - wherein the evaluation device (40) determines a second signal profile (120) of the second sensor signal over the cable section (110), - wherein the evaluation device (40) determines the wire break (B) in the cable section (110) moving past the sensor device (25) by assigning a sample signal profile of the sample set that matches the second signal profile (120).

2. Method according to claim 1, - wherein at least one first reference characteristic (100) of the lifting rope (20) is stored in the data memory (35), - wherein the first reference characteristic (100) comprises information of a first signal curve of a substantially new lifting rope (20) plotted against a first rope position (p1 (I)), - wherein the evaluation device (40) assigns the determined second signal curve (120) to a reference section (115) of the first reference characteristic (100), - wherein the evaluation device (40) determines a first cable position (p1 (I)) of the determined wire break (B) on the basis of the first reference characteristic (100).

3. Method according to one of the preceding claims, - wherein the evaluation device (40) is trained by means of a sample set of sample signal curves stored in the data memory (35), - wherein the trained evaluation device (40) evaluates the second signal curve (120) on the basis of the training.

4. Method according to one of the preceding claims, - wherein the evaluation device (40) assigns the pattern signal curve to the second signal curve (120) and / or the second signal curve (120) of the sensor signal to the first reference characteristic (100) by means of pattern recognition, in particular a time warping algorithm, in particular a dynamic time warping algorithm and / or FFT algorithm and / or a wavelet transformation, in particular a direct wavelet transformation.

5. Method according to one of the preceding claims, - wherein the evaluation device (40) carries out a self-learning algorithm to determine the wire break (B), - wherein the self-learning algorithm is preferably a one-class support vector machine algorithm and / or an isolation forest algorithm and / or a decision tree algorithm and / or a histogram-based outlier score algorithm.

6. Method according to one of the preceding claims, - wherein a predefined reference length is stored in the data memory (35), - wherein the evaluation device (40) determines a number of wire breaks (B) per reference length in the second signal curve (120) on the basis of the predefined reference length, - wherein the evaluation device (40) compares the determined number of wire breaks (B) per reference length with a predefined maximum threshold value (M), - wherein the evaluation device (40) provides information about a discard readiness of the lifting rope (20) at the data interface (45) when the predefined maximum threshold value (M) is exceeded.

7. Method according to one of the preceding claims, - wherein a predefined reference length is stored in the data memory (35), - wherein the evaluation device (40) determines a number of wire breaks (B) per reference length in the second signal curve (120) on the basis of the predefined reference length, - wherein the evaluation device (40) determines a maximum (MAX) of the determined number of wire breaks (B) per reference length, - wherein the evaluation device (40) determines a minimum distance (c) between the maximum (MAX) and a predefined maximum threshold value (M), - wherein, on the basis of the minimum distance (c), the evaluation device (40) provides warning information and / or a prediction about an impending discard readiness of the lifting rope (20) at the data interface (45).

8. Method according to one of claims 2 to 7, - wherein at least one threshold characteristic with at least a plurality of different threshold values ​​is stored in the data memory (35), - wherein the evaluation device (40) determines a deviation (b) between the second signal curve (120) and the first reference characteristic (100), - wherein the evaluation device (40) compares the deviation (b) with the threshold characteristic, - wherein, if at least one of the threshold values ​​of the threshold characteristic is exceeded, the evaluation device (40) verifies at least the information about the wire break (B).

9. Method according to claim 8, - wherein the evaluation device (40) determines an envelope curve on the basis of the first reference characteristic (100), - wherein the evaluation device (40) determines the threshold characteristic on the basis of the envelope curve.

10. Method according to one of claims 2 to 9, - wherein the first reference characteristic (100) is determined at the beginning of use of the lifting rope (20) by moving the lifting rope (20) past the sensor device (25) preferably over its entire possible length in an initialization process, - wherein the sensor device (25) generates a first sensor signal, which characterizes an interaction between the sensor device (25) and the lifting cable (20) moving past the sensor device (25), as a function of the first Rope position (p1 (I)) of the lifting rope (20) is generated and provided to the evaluation device (40) via the data interface (45), - wherein the evaluation device (40) determines a first signal curve of the sensor signal over the first cable position (p1 (I)), - wherein the first signal curve is stored as a first reference characteristic (100) in the data memory (35). 11 . Method according to one of claims 2 to 10, - wherein a running direction of the cable section (110) of the lifting cable (20) guided past the sensor device (25) is determined, - wherein, depending on the 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 curve are determined for the same running direction, - wherein in particular the second signal curve (120) is inverted on the basis of the second cable position (p2(l)) such that the first reference characteristic (100) and the second signal curve have the same running direction.

12. Method according to one of the preceding claims, - wherein the first signal curve forms a second reference characteristic (125) which is determined after the first reference characteristic (100), - and / or - wherein the evaluation device (40) determines matrix profiles for the first reference characteristic (100) and the first signal curve, - wherein the evaluation device (40) determines similarities and / or matches between the first reference characteristic (100) and the first signal curve on the basis of the determined matrix profiles.

13. Method according to one of the preceding claims, - wherein the first sensor signal and / or the second sensor signal is smoothed and / or pre-filtered before the first sensor signal and / or the second sensor signal is evaluated, - wherein, in particular, a Fast Fourier Transformation and / or a Wavelet Transformation, in particular a Direct Wavelet Transformation, and / or a low-pass filter is used for filtering, - and / or wherein the first sensor signal and / or the second sensor signal is compared with a predefined minimum threshold value, - wherein the first signal curve is determined on the basis of the first sensor signal that exceeds the predefined minimum threshold value, wherein the second signal curve is determined on the basis of the second sensor signal that exceeds the predefined minimum threshold value.

14. Method according to one of the preceding claims, - wherein the lifting system (10) lifts a load of at least 201 to 10,000 t inclusive, - wherein the second rope section is moved past the sensor device (25) when the load is lifted or lowered.

15. Lifting system (10) for a large-scale industrial plant, in particular a rolling mill and / or a continuous casting machine, and / or a goods handling point - wherein the lifting system (10) is designed to carry out a method according to one of the preceding claims, - wherein the lifting system (10) has at least one lifting rope (20), - wherein the lifting system (10) has a load-bearing capacity on the lifting rope (20) of at least 20t, - wherein the lifting system (10) is further preferably designed to lift and / or lower loads.

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