Wire rope inspection method, wire rope inspection system, and wire rope inspection device

Abstract

The present invention relates to a wire rope inspection method, a wire rope inspection system, and a wire rope inspection device. The wire rope inspection method performs second-order differential processing on the positive component or the negative component of the first-order differential waveform. Then, the absolute values of the positive component and the negative component of the second-order differential waveform are added in a state where they are shifted along the time axis so that the portions representing the abnormal portions of the wire rope coincide. Then, based on the generated added waveform, the abnormal portions of the wire rope are determined.

Description

Technical Field

[0001] The present invention relates to a wire rope inspection method, a wire rope inspection system, and a wire rope inspection device. Background Art

[0002] Conventionally, an inspection device for detecting a change in the magnetic flux of a wire rope has been known. Such a device is disclosed, for example, in International Publication No. 2018 / 138850.

[0003] The inspection device described in the above International Publication No. 2018 / 138850 includes a detection coil for detecting a change in the magnetic field of a wire rope. The detection coil is a differential coil composed of two coils. The detection signal of the differential coil is substantially 0 at a portion without damage or the like, and has a value greater than 0 at a portion with damage or the like. The inspection device described in the above International Publication No. 2018 / 138850 determines damage or the like of a wire rope based on the magnitude of the detection signal from the detection coil.

[0004] Here, although not described in the above International Publication No. 2018 / 138850, in the case of determining an abnormality of a wire rope based on the magnetic flux of the wire rope detected by a detection coil (detection unit), due to the shape of the wire rope or the like, the detected magnetic flux (magnetic characteristics) is not fixed but has an inherent change in magnetic characteristics. This inherent change in magnetic characteristics is included in the detection signal (detection signal) from the detection unit as noise. Since the difference between the signal of this noise and the signal of the abnormal portion is small, the detection accuracy of the abnormal portion of the wire rope is decreased. Therefore, it is desirable to distinguish the noise inherent in the wire rope from the abnormal portion of the wire rope and determine the abnormal portion of the wire rope with high accuracy. Summary of the Invention

[0005] The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a wire rope inspection method, a wire rope inspection system, and a wire rope inspection device capable of determining an abnormal portion of a wire rope with high accuracy by distinguishing the noise inherent in the wire rope from the abnormal portion of the wire rope.

[0006] To achieve the above object, the wire rope inspection method in the first aspect of the present invention includes the following steps: applying a magnetic field to the wire rope to be inspected; obtaining a detection signal by detecting the change in the magnetic flux of the wire rope to which the magnetic field is applied while relatively moving the detection unit with respect to the wire rope; obtaining a first-order differential waveform by performing a first-order differential process on the magnetic flux waveform, where the magnetic flux waveform is based on the signal waveform of the obtained detection signal; obtaining a second-order differential waveform by performing a second-order differential process on the positive component or the negative component of the obtained first-order differential waveform; generating an addition waveform by adding the positive component of the obtained second-order differential waveform and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the parts representing the abnormal part of the wire rope coincide; and determining the abnormal part of the wire rope when the value based on the generated addition waveform is greater than a specified determination threshold. In addition, the "abnormal part" of the wire rope is a broad concept including parts where the cross-sectional area or composition of the wire rope has changed, such as wire breakage, kinking, rusting, and attachment of foreign objects.

[0007] The wire rope inspection system in the second aspect of the present invention includes: a wire rope inspection device that detects the change in the magnetic flux of the wire rope to be inspected; and a processing device that performs a process of determining the abnormal part of the wire rope based on the measurement result of the wire rope inspection device on the wire rope. Among them, the wire rope inspection device includes: an exciting unit that applies a magnetic field to the wire rope; and a detection unit that obtains a detection signal by detecting the change in the magnetic flux of the wire rope to which the magnetic field is applied by the exciting unit while relatively moving with respect to the wire rope. The processing device includes: a first-order differential processing unit that obtains a first-order differential waveform by performing a first-order differential process on the magnetic flux waveform, where the magnetic flux waveform is based on the signal waveform obtained by the detection unit; a second-order differential processing unit that obtains a second-order differential waveform by performing a second-order differential process on the positive component or the negative component of the first-order differential waveform obtained by the first-order differential processing unit; an addition processing unit that generates an addition waveform by adding the positive component of the second-order differential waveform obtained by the second-order differential processing unit and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the parts representing the abnormal part of the wire rope coincide; and a determination processing unit that determines the abnormal part of the wire rope when the value based on the addition waveform generated by the addition processing unit is greater than a specified determination threshold.

[0008] The wire rope inspection device in the third aspect of the present invention includes: an excitation unit that applies a magnetic field to a wire rope to be inspected; a detection unit that obtains a detection signal by detecting a change in magnetic flux of the wire rope to which the magnetic field is applied by the excitation unit while relatively moving with respect to the wire rope; and a processing unit that performs a process of determining an abnormal portion of the wire rope based on the detection signal obtained by the detection unit. The processing unit includes: a first differentiation processing unit that obtains a first-order differentiation waveform by performing a first differentiation process on a magnetic flux waveform, the magnetic flux waveform being a signal waveform based on the detection signal obtained by the detection unit; a second differentiation processing unit that obtains a second-order differentiation waveform by performing a second differentiation process on a positive component or a negative component of the first-order differentiation waveform obtained by the first differentiation processing unit; an addition processing unit that generates an addition waveform by adding the positive component of the second-order differentiation waveform obtained by the second differentiation processing unit and the absolute value of the negative component of the obtained second-order differentiation waveform in a state where they are shifted along the time axis so that portions representing the abnormal portion of the wire rope coincide; and a determination processing unit that determines the abnormal portion of the wire rope when the value of the addition waveform generated by the addition processing unit is greater than a specified determination threshold value.

[0009] In the wire rope inspection method according to the first aspect of the present invention, the wire rope inspection system according to the second aspect, and the wire rope inspection device according to the third aspect, as described above, a first-order differential waveform is obtained by performing a first differentiation process on a magnetic flux waveform that is a signal waveform based on the acquired detection signal. Then, a second-order differential waveform is obtained by performing a second differentiation process on the positive component or the negative component of the acquired first-order differential waveform. Here, the shape of the portion corresponding to the abnormal portion in the shape of the magnetic flux waveform has either a rising shape to the right or a falling shape to the right depending on the type of the abnormal portion (such as wire breakage, kinking, rusting, attachment of foreign matter, etc.). Therefore, the waveform corresponding to the abnormal portion in the first-order differential waveform is included in either the positive component or the negative component depending on the type of the abnormal portion. For example, when the abnormal portion is a wire break, the shape of the waveform corresponding to the abnormal portion is rising to the right. Thus, when the abnormal portion is a wire break, the waveform of the portion corresponding to the abnormal portion in the first-order differential waveform is only included in the positive component of the first-order differential waveform. In contrast, in the present invention, a second-order differential waveform is obtained by performing a second differentiation process on the positive component or the negative component of the acquired first-order differential waveform. Therefore, it is possible to perform the second differentiation process only on the positive component or the negative component extracted in a manner corresponding to the type of the abnormal portion. Therefore, it is possible to perform the second differentiation process in a state where the waveform of the component that does not include the abnormal portion but only includes noise is eliminated. Moreover, in the present invention, as described above, an addition waveform is generated by adding the absolute value of the negative component of the acquired second-order differential waveform to the positive component of the acquired second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal portions of the wire rope coincide. Thus, based on the second-order differential waveform obtained in a state where the waveform of the component that does not include the abnormal portion but only includes noise is eliminated, the absolute value of the negative component of the second-order differential waveform is added to the positive component of the second-order differential waveform in a manner such that the portions representing the abnormal portions of the wire rope coincide, thereby generating an addition waveform. Therefore, it is possible to generate an addition waveform having a large peak such that the portion corresponding to the abnormal portion is more prominent than the noise other than the abnormal portion. Therefore, it is possible to distinguish between the inherent noise of the wire rope and the abnormal portion of the wire rope by determining the peak of the addition waveform. As a result, it is possible to accurately determine the abnormal portion of the wire rope by distinguishing between the inherent noise of the wire rope and the abnormal portion of the wire rope. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram showing the overall structure of the wire rope inspection system according to the first embodiment.

[0011] Figure 2 is a block diagram showing the overall structure of the wire rope inspection system according to the first embodiment.

[0012] Figure 3It is a diagram showing the configuration of the magnetization unit, exciting unit, and detection unit of the wire rope inspection device according to the first embodiment.

[0013] Figure 4 It is a schematic diagram for explaining the structure of the detection coil of the detection unit.

[0014] Figure 5 It is a diagram for explaining the generation of the magnetic flux waveform.

[0015] Figure 6 The (A) of is a diagram for explaining the abnormal waveform indicating the abnormal part and is a diagram showing the abnormal waveform of wire breakage of the wire material.

[0016] Figure 6 The (B) of is a diagram for explaining the abnormal waveform indicating the abnormal part and is a diagram showing the abnormal waveform of kinking.

[0017] Figure 7 It is a diagram showing an example of distinguishing the magnetic flux waveform according to the type of abnormal part.

[0018] Figure 8 It is a diagram for explaining the setting of processing parameters.

[0019] Figure 9 It is a diagram for explaining the differential processing.

[0020] Figure 10 It is a diagram for explaining the generation of the second-order differential waveform.

[0021] Figure 11 It is a diagram for explaining the shift processing.

[0022] Figure 12 It is a diagram for explaining the added waveform and the determination threshold.

[0023] Figure 13 It is a flowchart for explaining the wire rope inspection method according to the first embodiment.

[0024] Figure 14 It is a block diagram showing the overall structure of the wire rope inspection system according to the second embodiment.

[0025] Figure 15 It is a diagram for explaining the setting of the shift amount according to the second embodiment.

[0026] Figure 16 It is a block diagram showing the overall structure of the wire rope inspection system according to the third embodiment.

[0027] Figure 17 It is a diagram for explaining the acquisition of the magnetic flux waveform according to the third embodiment.

[0028] Figure 18It is a block diagram showing the overall structure of the wire rope inspection system according to the fourth embodiment.

[0029] Figure 19 It is a diagram for explaining the first-order differential waveform and the extraction determination threshold of the fourth embodiment.

[0030] Figure 20 It is a block diagram showing the overall structure of the wire rope inspection device according to the modification examples of the first to fourth embodiments of the present invention. Detailed Embodiment

[0031] Hereinafter, embodiments for embodying the present invention will be described based on the drawings.

[0032] [First Embodiment]

[0033] First, with reference to Figures 1 to 12 the structure of the wire rope inspection system 100 according to the first embodiment of the present invention will be described. In addition, in the following description, "orthogonal" means crossing at an angle of 90 degrees or near 90 degrees. Also, "parallel" includes parallel and substantially parallel.

[0034] (Structure of Wire Rope Inspection System)

[0035] As Figure 1 shown, the wire rope inspection system 100 includes a wire rope inspection device 101 and a processing device 102. The wire rope inspection device 101 detects changes in the magnetic flux of the wire rope W as an inspection object. Moreover, the wire rope inspection device 101 is configured to send the measurement result obtained by detecting the change in the magnetic flux of the wire rope W to the processing device 102. The processing device 102 executes a process of determining an abnormal portion of the wire rope W based on the measurement result of the wire rope W by the wire rope inspection device 101. In addition, the processing device 102 displays the measurement result of the wire rope W by the wire rope inspection device 101 and the determination result of the abnormal portion.

[0036] The wire rope inspection system 100 inspects the wire rope W provided in the elevator 103. Specifically, the wire rope inspection system 100 is a system for inspecting an abnormal portion (such as wire breakage) of the wire rope W of the elevator 103 as an inspection object. In addition, the wire rope inspection system 100 is a system that can use the total magnetic flux method of measuring the magnetic flux inside the wire rope W to confirm an abnormality of the wire rope W that is difficult to visually confirm. When the wire rope W includes an abnormal portion, the magnetic flux at the abnormal portion is different from the magnetic flux at the normal portion. The total magnetic flux method is different from the method of only measuring the leakage magnetic flux from the abnormal portion on the surface of the wire rope W, and is a method that can also measure the abnormal portion inside the wire rope W.

[0037] (Structure of Elevator)

[0038] As shown Figure 1 in FIG. 1, the elevator 103 includes a car room 103a, a rope pulley 103b, a rope pulley 103c, a control device 103d, and a wire rope W. The elevator 103 is configured such that the car room 103a loaded with people, goods, etc. moves in the vertical direction by winding the wire rope W as the rope pulley 103b (pulley) provided on the hoist rotates. In addition, the elevator 103 is, for example, a wire rope type elevator of a rewinding method (full winding method) having two rope pulleys 103b and 103c. The rewinding method refers to the following structure: the wire rope W guided from the rope pulley 103b of the hoist to the rope pulley 103c as a deflector pulley returns to the rope pulley 103b of the hoist again, so that the wire rope W is wound twice around the rope pulley 103b. The control device 103d includes a control panel that controls the operation of each part of the elevator 103. In addition, the control device 103d includes a wireless communication module, etc., and is configured to be able to communicate with the processing device 102.

[0039] The wire rope W is formed by braiding a wire material having magnetism (for example, strand braiding), and is a magnetic body made of a long material. In order to prevent the wire rope W from being cut due to deterioration, the state (presence or absence of abnormal parts) of the wire rope W is inspected by the wire rope inspection device 101. The wire rope W whose degree of deterioration is judged to exceed the determined reference as the measurement result of the magnetic flux of the wire rope W is replaced by the inspection operator. In addition, in Figure 1 the example shown in FIG. 2, for convenience, only one wire rope W is shown, but the elevator 103 includes a plurality of wire ropes W. For example, the elevator 103 includes four wire ropes W.

[0040] The wire rope W is arranged to extend in the X direction at the position of the wire rope inspection device 101 (refer to Figure 3 FIG. 3). The wire rope inspection device 101 measures the magnetic flux of the wire rope W while relatively moving along the surface of the wire rope W in the extending direction (X direction) of the wire rope W. When the wire rope W moves by itself as in the case of the wire rope W used in the elevator 103, the magnetic flux of the wire rope W is measured by the wire rope inspection device 101 while moving the wire rope W in the X2 direction. Thus, the wire rope inspection device 101 inspects the damage at each position in the X direction of the wire rope W by measuring the magnetic flux at each position in the X direction of the wire rope W.

[0041] (Structure of wire rope inspection device)

[0042] As Figure 2 and Figure 3As shown, the wire rope inspection device 101 includes a magnetic field adjustment unit 10, an excitation unit 20, a detection unit 30, and a control board 40. The wire rope inspection device 101 is configured to inspect the wire rope W between the rope sheaves 103b and 103c of the elevator 103.

[0043] The magnetic field adjustment unit 10 adjusts the magnetization direction of the wire rope W by applying a magnetic field to the wire rope W in advance. For example, the magnetic field adjustment unit 10 is a permanent magnet. In addition, the magnetic field adjustment unit 10 includes a pair of magnetic field adjustment units 10a and 10b. The pair of magnetic field adjustment units 10a and 10b are arranged on both sides in the short side direction of the wire rope W (the direction orthogonal to the extending direction of the wire rope W, the Z direction) with the wire rope W sandwiched therebetween. Specifically, the magnetic field adjustment unit 10a is arranged on the Z1 direction side of the wire rope W. Moreover, the magnetic field adjustment unit 10b is arranged on the Z2 direction side of the wire rope W. Moreover, the magnetic field adjustment unit 10 is arranged such that the N pole (with diagonal lines) facing the Z2 direction of the magnetic field adjustment unit 10a faces the N pole (with diagonal lines) facing the Z1 direction of the magnetic field adjustment unit 10b with the wire rope W therebetween. The magnetic field adjustment units 10a and 10b are configured to be able to apply a strong magnetic field so that the magnetization directions of the wire rope W are substantially the same.

[0044] The excitation unit 20 is configured to apply a magnetic field (magnetic flux) to the wire rope W to excite (vibrate) the magnetization state of the wire rope W. Specifically, the excitation unit 20 includes an excitation coil 21. The excitation coil 21 is arranged to wind around all of the multiple (4) wire ropes W along the extending direction (X direction) of the wire rope W. In addition, the excitation coil 21 is arranged to wind outside the detection coils 31a and 31b of the detection unit 30 described later with respect to the wire rope W.

[0045] The excitation coil 21 generates a magnetic flux (magnetic field) along the extending direction (X direction) of the wire rope W inside the coil (inside the turns of the coil) by passing an excitation alternating current. Specifically, an alternating current (excitation current) having a fixed magnitude and a fixed frequency is passed through the excitation unit 20 (excitation coil 21) under the control of the processing unit 41 of the control board 40 described later, whereby a magnetic field is applied in a vibrating manner in the extending direction (X direction) of the wire rope W. That is, the excitation unit 20 causes the magnetic field (magnetic flux) pre-adjusted by the magnetic field adjustment unit 10 in the wire rope W to vibrate in a manner that periodically presents a magnetic field in the X1 direction and a magnetic field in the X2 direction.

[0046] The detection unit 30 is configured to obtain a detection signal by detecting the change in the magnetic flux of the wire rope W while relatively moving with the wire rope W and after a magnetic field has been pre-applied to the magnetization unit 10 (after magnetization), the excitation unit 20 applies a magnetic field (the magnetic field is excited) to cause vibration. In the wire rope inspection system 100 of the first embodiment, since the detection unit 30 needs to detect the change in the magnetic flux of the wire rope W moving in the X2 direction, the detection unit 30 detects the change in the magnetic flux of the wire rope W while relatively moving with the wire rope W.

[0047] Specifically, the detection unit 30 includes a detection coil 31a disposed on one side (Z1 direction side) in the direction (Z direction) orthogonal to the direction (X direction) in which the wire rope W extends, and a detection coil 31b disposed on the other side (Z2 direction side). In addition, the detection coils 31a and 31b are arranged such that one wire rope W is sandwiched between two coils in a state of surrounding one wire rope W. Further, one detection coil 31a and one detection coil 31b are provided for each wire rope among multiple (4) wire ropes W.

[0048] As Figure 4 shown, the detection coils 31a and 31b are arranged to wind around the wire rope W along the direction in which the wire rope W extends. Specifically, the detection coil 31a and the detection coil 31b are each independent saddle-shaped coils (saddle type coils). The detection coil 31a and the detection coil 31b are respectively arranged to cover each half circumference of the wire rope W. Thus, the detection coils 31a and 31b are arranged such that by combining the detection coil 31a and the detection coil 31b, two saddle-shaped coils wind around the entire circumference of the wire rope W along the direction (X direction) in which the wire rope W extends. In addition, the detection coils 31a and 31b are respectively constituted by conductor patterns provided on a flexible substrate. In addition, in this specification, "winding" is described as a concept including not only the number of times (angles) of winding (coiling) more than one full turn, but also less than one turn (for example, half a turn).

[0049] In addition, the detection coils 31a and 31b are respectively arranged to wind along the direction (X direction) in which the wire rope W extends, whereby the change in the magnetic flux in the direction of the inside of the coil penetrating along the direction (X direction) in which the wire rope W extends is detected (measured). Moreover, the detection coils 31a and 31b are configured to detect the change in the magnetic flux (magnetic field) that periodically changes with time due to the excitation unit 20 (excitation coil 21). In addition, the detection coils 31a and 31b output a detection signal indicating the detected change in magnetic flux to the signal acquisition unit 42 of the control substrate 40 described later (refer to Figure 2 ).

[0050] In addition, the detection coils 31a and 31b are connected differentially. Specifically, by combining the detection coil 31a and the detection coil 31b, two coil loops with opposite directions are formed on the X1 direction side and the X2 direction side around the wire rope W, respectively. Moreover, by synthesizing the detection signal of the detection coil 31a and the detection signal of the detection coil 31b, a detection signal obtained by synthesizing the changes in magnetic fluxes detected by the two coil loops with opposite directions is acquired. That is, the detection unit 30 is configured to acquire the detection signal of the differential coil by synthesizing the detection signal of the detection coil 31a and the detection signal of the detection coil 31b.

[0051] As Figure 2 shown, the control substrate 40 includes a processing unit 41, a signal acquisition unit 42, and a communication unit 43. The control substrate 40 controls each part of the wire rope inspection device 101 through the control processing of the processing unit 41. The processing unit 41 includes a processor such as a CPU (Central Processing Unit), a memory, and an AD converter. The control substrate 40 controls the operation of the exciting unit 20 (exciting coil 21) based on the control signal from the processing unit 41. In addition, the signal acquisition unit 42 acquires (receives) the detection signal from the detection unit 30 (detection coils 31a and 31b). The signal acquisition unit 42 includes an amplifier. Moreover, the signal acquisition unit 42 amplifies the acquired detection signal and outputs (sends) it to the processing unit 41. Moreover, the communication unit 43 is configured to be able to communicate with the processing device 102. The communication unit 43 includes a wireless communication module capable of wireless communication through wireless LAN and Bluetooth (registered trademark), etc. The communication unit 43 outputs (sends) the acquired detection signal to the processing device 102. In addition, the connection between the wire rope inspection device 101 and the processing device 102 via the communication unit 43 may also be a wired connection.

[0052] (Structure of the processing device)

[0053] As Figure 2 shown, the processing device 102 includes a control unit 50, a storage unit 60, a touch panel 70, and a communication unit 80. The processing device 102 is provided separately from the wire rope inspection device 101. Moreover, the processing device 102 is, for example, a tablet terminal such as a tablet PC (Personal Computer) used by an inspection operator who inspects the wire rope W.

[0054] The control unit 50 controls each part of the processing device 102. The control unit 50 includes a processor such as a CPU, a memory, etc. The control unit 50 performs the following processing: Based on the measurement result (detection signal) of the wire rope W received via the communication unit 80, it determines the abnormal part of the wire rope W such as wire breakage. In addition, the details of the determination process of the abnormal part performed by the control unit 50 will be described later.

[0055] The storage unit 60 is a storage device including, for example, a flash memory. The storage unit 60 is used to store (save) information such as the measurement result of the wire rope W obtained and the determination result of the abnormal part of the wire rope W by the control unit 50. In addition, the storage unit 60 stores a program 61 and processing parameters 62 for determining the abnormal part of the wire rope W.

[0056] The touch panel 70 is used to display information such as the measurement result of the wire rope W and the analysis result (determination result of the abnormal part) of the measurement result of the wire rope W by the control unit 50. In addition, the touch panel 70 receives the input operations performed by the inspection operator.

[0057] The communication unit 80 is configured to be able to communicate with the wire rope inspection device 101 and the control device 103d of the elevator 103. The communication unit 80 is a communication interface. Specifically, the communication unit 80 includes a wireless communication module capable of performing wireless communication via wireless LAN, Bluetooth (registered trademark), etc. The processing device 102 receives the measurement result (detection signal) of the wire rope W from the wire rope inspection device 101 via the communication unit 80. In addition, when the inspection of the wire rope W is started based on the input operation performed by the inspection operator, the processing device 102 sends a signal indicating the start of the inspection to the wire rope inspection device 101 and the elevator 103 (the control device 103d of the elevator 103) via the communication unit 80.

[0058] In addition, the processing device 102 is configured to acquire a signal indicating the position of the wire rope W together with the acquired detection signal (measurement result). Moreover, the processing device 102 is configured to store the detection signal in association with the position information indicating the position of the wire rope W corresponding to the detection signal. The position information of the wire rope W can be acquired using a position sensor such as an encoder, or can be calculated based on the operating speed of the elevator 103 and the passage of the inspection time for the inspection.

[0059] (Determination process of the abnormal part performed by the processing device)

[0060] Next, referring to Figure 2 and Figures 5 to 12To explain the process of determining the abnormal parts performed by the processing device 102. In the wire rope inspection system 100, it is configured to determine for each type of abnormal part (such as wire breakage, kinking, rusting, foreign object attachment, etc.). In the first embodiment, an example is described in which the abnormal parts to be determined are two types, namely wire breakage and kinking.

[0061] As Figure 2 shown, the control unit 50 of the processing device 102 includes a waveform generation unit 51, an extraction processing unit 52, a parameter setting unit 53, a first derivative processing unit 54, a second derivative processing unit 55, an addition processing unit 56, and a determination processing unit 57. Specifically, the control unit 50 as hardware is configured to include the waveform generation unit 51, the extraction processing unit 52, the parameter setting unit 53, the first derivative processing unit 54, the second derivative processing unit 55, the addition processing unit 56, and the determination processing unit 57 as functional blocks of software (program 61). The control unit 50 is configured to: by executing the program 61, perform the process of determining the abnormal parts of the wire rope W based on the acquired detection signal.

[0062] The waveform generation unit 51 (control unit 50) generates a magnetic flux waveform as Figure 5 shown, which is based on the signal waveform of the detection signal acquired from the wire rope inspection device 101 (detection unit 30) via the communication unit 80. The sampling frequency of the magnetic flux waveform is, for example, 1 [kHz]. Therefore, the generated magnetic flux waveform is a set of discrete detection signals acquired every 1 [ms] (millisecond) (refer to Figure 9 ). In addition, in order to reduce electrical noise, the waveform generation unit 51 performs a moving average process for each specified interval (such as 20 [ms]), thereby generating the magnetic flux waveform. That is, the waveform generation unit 51 is configured to: for the detection signal acquired every 1 [ms], sample the average value of the interval including the previous and subsequent 10 [ms] every 1 [ms], thereby generating the magnetic flux waveform. In addition, the magnetic flux waveform is represented by a curve graph with the horizontal axis set as time t [ms] and the vertical axis set as the value F(t) (t: time) based on the detection signal acquired by the waveform generation unit 51. In addition, Figure 5 the interval t1 is the magnetic flux waveform of the part corresponding to the abnormal part of wire breakage of the wire rope W (the part indicating the abnormal part). The generated magnetic flux waveform has a shape such that the waveform of the abnormal part is buried in the noise.

[0063] In addition, as Figure 6As shown, the shape (width, slope, curvature, etc.) of the signal waveform of the abnormal portion of the wire rope W, i.e., the abnormal waveform, is substantially fixed according to the type of the abnormal portion. Specifically, the abnormal waveform has one of the shapes of rising to the right and falling to the right according to the type of the abnormal portion. For example, when the type of the abnormal portion is a wire break, the magnetic flux leaks out from the break portion, so the abnormal waveform rises to the right. Moreover, when the type of the abnormal portion is a kink, contrary to the wire break, the abnormal waveform falls to the right. In detail, the abnormal waveform of the wire break increases at a prescribed ratio in a manner where the waveform rises to the right after the detected value decreases once along the time axis. After that, the detected value decreases again. The abnormal waveform of the kink is contrary to that of the wire break. After the detected value increases once, it decreases at a prescribed ratio in a manner where the waveform falls to the right. After that, the detected value increases again.

[0064] As Figure 7 shown, in the first embodiment, the extraction processing unit 52 (control unit 50) is configured to determine the type of the abnormal portion included in the generated magnetic flux waveform based on the shape of the generated magnetic flux waveform. That is, the extraction processing unit 52 is configured to separately extract, from the generated magnetic flux waveform, the portion suspected of being the abnormal portion of the wire break and the portion suspected of being the abnormal portion of the kink. For example, the extraction processing unit 52 extracts, for each prescribed interval, the portion where the shape of the magnetic flux waveform changes in the order of decreasing, increasing, and decreasing as the portion suspected of being the abnormal portion of the wire break. Similarly, the extraction processing unit 52 extracts, for each prescribed interval, the portion where the shape of the magnetic flux waveform changes in the order of increasing, decreasing, and increasing as the portion suspected of being the abnormal portion of the kink.

[0065] In addition, as Figure 8As shown, the parameter setting unit 53 (control unit 50) sets the processing parameter 62 for the determination process of the abnormal part of the wire rope W. Here, in the wire rope inspection system 100 of the first embodiment, a plurality of processing parameters 62 are stored in advance in the storage unit 60 in a manner corresponding to the types of abnormal parts (wire breakage and kink) of the wire rope W to be inspected. The processing parameter 62 includes, for example, the first differential interval dt1, the second differential interval dt2, and the shift amount D, which will be described later. The storage unit 60 stores the combination of the processing parameters 62 as a table for each type of abnormal part of the wire rope W. When determining the abnormal part of the wire breakage, the parameter setting unit 53 sets the first differential interval dt1, the second differential interval dt2, and the shift amount D corresponding to the abnormal part of the wire breakage. Further, when determining the abnormal part of the kink, the parameter setting unit 53 sets the first differential interval dt1, the second differential interval dt2, and the shift amount D corresponding to the abnormal part of the kink. In addition, the processing parameter 62 may be set not only in a manner corresponding to the type of the abnormal part, but also in a manner corresponding to the type (width, material, etc.) of the wire rope W to be inspected.

[0066] 〈Differential Processing〉

[0067] As Figure 9 and Figure 10 shown, in the first embodiment, the control unit 50 (the first differential processing unit 54 and the second differential processing unit 55) obtains the second-order differential waveform by performing the differential processing on the magnetic flux waveform twice. Further, in the following description, an example of the case of determining the abnormal part of the wire breakage among the two types of abnormal parts, i.e., the wire breakage and the kink, will be described.

[0068] As Figure 9 shown, the first differential processing unit 54 (control unit 50) performs the first differential processing based on the prescribed first differential interval dt1 on the magnetic flux waveform obtained by extracting the part suspected of being the wire breakage in sequence along the time axis (horizontal axis) in order to determine the abnormal part of the wire breakage. For example, when performing the differential processing at the time point a of the magnetic flux waveform, the first differential processing at the time point a is performed by obtaining the difference between the value F(b) of the magnetic flux waveform at the time point b, which is a prescribed first differential interval dt1 after the time point a, and the value F(a) of the magnetic flux waveform at the time point a. That is, when the value of the result obtained by performing the first differential processing at the time point a is set as F′(a), the relationship F′(a) = F(b) - F(a), b = a + dt1 holds. The first differential processing unit 54 obtains the first-order differential waveform by performing the first differential processing on each sampling period (1 [ms]) in sequence along the time axis. Further, the value of the first-order differential waveform is represented as F′(t).

[0069] In addition, as Figure 6 shown, in the first embodiment, the first differential interval dt1 is set based on the signal waveform representing the abnormal portion of the wire rope W, i.e., the abnormal waveform, which is obtained in advance. When determining the abnormal portion of the wire breakage, in the wire rope inspection system 100 of the first embodiment, the first differential interval dt1 is set to an interval approximately equal to the width of the rising portion to the right of the abnormal waveform representing the portion of the wire breakage obtained in advance, and is stored in the storage unit 60 in advance as the processing parameter 62. For example, the first differential interval dt1 in the case where the abnormal portion is a wire breakage is 15 [ms] (15 sampling numbers). Similarly, when determining the abnormal portion of the kink, the first differential interval dt1 is set to an interval approximately equal to the width of the falling portion to the right of the abnormal waveform representing the portion of the kink obtained in advance, and is stored in the storage unit 60 in advance as the processing parameter 62.

[0070] Moreover, in the first embodiment, as Figure 10 shown, before performing the second differential processing, the second differential processing unit 55 (control unit 50) extracts either the positive component or the negative component of the first differential waveform based on the shape of the magnetic flux waveform. Here, when the type of the abnormal portion is a wire breakage, the waveform of the portion corresponding to the abnormal portion rises to the right. Therefore, the portion of the magnetic flux waveform that falls to the right does not represent the waveform of the abnormal portion but represents the waveform of noise. Thus, there is no portion representing the abnormal portion of the wire breakage in the negative component of the first differential waveform. When determining the abnormal portion of the wire breakage based on the shape of the magnetic flux waveform, the second differential processing unit 55 extracts the positive component of the first differential waveform by setting all the negative components of the obtained first differential waveform to 0 (eliminating). In addition, the value of the positive component of the first differential waveform is represented as F′ (+) (t). In addition, when the abnormal portion is a kink, the abnormal waveform falls to the right. Therefore, the second differential processing unit 55 extracts the negative component of the first differential waveform based on the magnetic flux waveform.

[0071] Furthermore, the second differentiation processing unit 55 is configured to perform second differentiation processing on the positive component of the first differentiation waveform extracted based on the first differentiation waveform in sequence along the time axis based on the second differentiation interval dt2. The second differentiation processing is the same as the first differentiation processing. In addition, similar to the first differentiation interval dt1, the second differentiation interval dt2 is preset based on the abnormal waveform representing the abnormal portion of the wire breakage and stored in the storage unit 60. For example, the length of the second differentiation interval dt2 is approximately half (e.g., 7 [ms]) of the length of the first differentiation interval dt1, which is an interval approximately equal to the width of the rising portion to the right of the abnormal waveform of the wire breakage. In this way, by performing the second differentiation processing, the second differentiation processing unit 55 generates a second-order differentiation waveform. In addition, the value of the second-order differentiation waveform is represented as F″(t).

[0072] 〈Addition Processing〉

[0073] As Figure 11 and Figure 12 shown, in the first embodiment, the addition processing unit 56 (control unit 50) is configured to generate an added waveform by adding the positive component of the acquired second-order differentiation waveform and the absolute value of the negative component of the acquired second-order differentiation waveform in a state where they are shifted along the time axis so that the portion representing the abnormal portion of the wire rope W (the portion of the interval t1 in the figure) coincides.

[0074] Specifically, as Figure 11 shown, the addition processing unit 56 acquires the positive component of the second-order differentiation waveform and the negative component of the second-order differentiation waveform respectively. Moreover, the absolute value of the negative component of the second-order differentiation waveform is acquired. In addition, the value of the positive component of the second-order differentiation waveform is represented as F″ (+) (t). In addition, the absolute value of the negative component of the second-order differentiation waveform is represented as |F″ (-) (t)|.

[0075] Then, in the first embodiment, the addition processing unit 56 shifts the absolute value of the negative component of the second-order differentiation waveform along the time axis based on a preset shift amount D so that the portion representing the abnormal portion of the wire rope W (the portion corresponding to the abnormal portion) coincides. Specifically, the addition processing unit 56 shifts the absolute value of the negative component of the second-order differentiation waveform in the negative direction of the time axis (the left direction of the horizontal axis) by the magnitude of the shift amount D preset by the parameter setting unit 53. That is, the absolute value of the shifted negative component of the second-order differentiation waveform is represented as |F″ (-) (t + D)|.

[0076] In addition, in the first embodiment, the shift amount D, like the first differential interval dt1 and the second differential interval dt2, is preset based on the abnormal waveform indicating the abnormal portion and stored in the storage unit 60. The shift amount D is, for example, a value greater than the first differential interval dt1 (e.g., 20 [ms]) of an interval substantially equal to the width of the portion of the abnormal waveform that rises or falls to the right.

[0077] Then, as Figure 12 shown, the addition processing unit 56 generates an added waveform by adding the positive component of the second-order differential waveform and the absolute value of the negative component of the shifted second-order differential waveform. In addition, the value of the generated added waveform is represented as F″ (+) (t)+|F″ (-) (t + D)|. In the added waveform, the difference between the abnormal portion and the noise is greater than that in the magnetic flux waveform.

[0078] 〈Determination Processing〉

[0079] Moreover, the determination processing unit 57 (control unit 50) is configured to: when the value of the generated added waveform (the value represented by F″ (+) (t)+|F″ (-) (t + D)|) is greater than a specified determination threshold S, determine the abnormal portion of the wire rope W. The determination threshold S is, for example, preset by the parameter setting unit 53 in a manner corresponding to the set abnormal portion. Alternatively, the determination threshold S can be set by selecting from multiple candidates based on an input operation performed by the inspection operator. Specifically, when the abnormal portion is a wire break of the wire material, a plurality of determination thresholds S are stored in the storage unit 60 as processing parameters 62 according to the number of wire breaks of the wire material. Then, based on receiving an operation in which the inspection operator selects the number of wire breaks to be determined, the parameter setting unit 53 sets the determination threshold S corresponding to the selected number of wire breaks.

[0080] Then, the determination processing unit 57 generates a determination result in which the portion where the value of the added waveform is greater than the determination threshold S is set as the abnormal portion. The generated determination result includes information capable of identifying the position of the portion determined to be the abnormal portion in the wire rope W. The determination processing unit 57, for example, generates a determination result including position information that represents the position of the abnormal portion in the wire rope W using the distance with the starting inspection position in the wire rope W as 0. In addition, when determining the abnormal portion of a kink, the abnormal portion is determined by the same processing.

[0081] 〈Display of Results〉

[0082] The control unit 50 displays the determination result (analysis result) of the determination processing unit 57 for the abnormal part on the touch panel 70. For example, the control unit 50 causes the position of the wire rope W determined to be the abnormal part to be displayed numerically on the touch panel 70. In addition, the control unit 50 causes the character information capable of identifying the type of the determined abnormal part (wire breakage or kink) to be displayed together. In addition, the control unit 50 may also display the added waveform value in the case where the wire rope W is determined to be an abnormal part in addition to displaying the position of the wire rope W.

[0083] (Wire Rope Inspection Method of the First Embodiment)

[0084] Next, with reference to Figure 13 the wire rope inspection method of the first embodiment will be described. This wire rope inspection method is executed by the wire rope inspection device 101 and the processing device 102 of the wire rope inspection system 100. That is, steps 602 and 603 show the control processing performed by the processing unit 41 of the wire rope inspection device 101. Moreover, steps 601 and 604 to 612 show the control processing performed by the control unit 50 of the processing device 102.

[0085] First, in step 601, an input operation for starting the inspection of the wire rope W is received. Specifically, based on the input operation on the touch panel 70, the inspection of the wire rope W is started. Then, a signal indicating the start of the inspection is sent to the control device 103d of the elevator 103 and the processing unit 41 of the wire rope inspection device 101.

[0086] Next, in step 602, a magnetic field is applied to the wire rope W. Then, in step 603, while relatively moving the detection unit 30 with respect to the wire rope W, the change in the magnetic flux of the wire rope W to which the magnetic field is applied is detected by the detection unit 30 to obtain a detection signal.

[0087] Next, in step 604, a magnetic flux waveform is generated based on the obtained detection signal.

[0088] Next, in step 605, the type of the abnormal part included in the magnetic flux waveform is determined based on the shape of the generated magnetic flux waveform. Specifically, the part of the abnormal part presumed to be a wire break and the part of the abnormal part presumed to be a kink are separately extracted from the magnetic flux waveform.

[0089] Next, in step 606, the processing parameter 62 corresponding to the type of the abnormal part to be determined is set. Specifically, before the determination processing, the first differential interval dt1, the second differential interval dt2, the shift amount D, and the determination threshold S for performing the determination processing are preset in a manner corresponding to each type of the type of the abnormal part (wire break and kink).

[0090] Next, in step 607, first-order differentiation processing based on a prescribed first differentiation interval dt1 is sequentially performed on the magnetic flux waveform along the time axis. Additionally, by performing the first-order differentiation processing, a first-order differential waveform is obtained. Then, in step 608, the positive or negative component of the first-order differential waveform is extracted based on the shape of the magnetic flux waveform. Then, in step 609, differentiation processing based on a prescribed second differentiation interval dt2 is sequentially performed on the positive or negative component of the first-order differential waveform along the time axis. Additionally, a second-order differential waveform is generated by performing the second-order differentiation processing.

[0091] Next, in step 610, an addition waveform is generated by adding the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal part of the wire rope W overlap. Specifically, the addition waveform is generated by adding the absolute value of the negative component of the second-order differential waveform to the positive component of the second-order differential waveform in a state where it is shifted along the time axis based on a preset shift amount D.

[0092] Next, in step 611, when the value of the generated addition waveform (the value represented by F″ (+) (t)+|F″ (-) (t + D)|) is greater than a prescribed determination threshold S, the abnormal part of the wire rope W is determined. Then, in step 612, the determination result is displayed on the touch panel 70.

[0093] In addition, the processing of steps 607 to 611 is performed separately for each type of abnormal part (wire breakage and kink). Additionally, regarding the generation of the magnetic flux waveform in step 604, the determination of the type of abnormal part in step 605, and the setting of the processing parameter 62 in step 606, any of these steps can be executed first.

[0094] (Effect of the First Embodiment)

[0095] In the wire rope inspection method of the first embodiment, the following effects can be obtained.

[0096] In the wire rope inspection method of the first embodiment, as described above, a first-order differential waveform is obtained by performing a first differentiation process on a magnetic flux waveform that is a signal waveform based on the acquired detection signal. Then, a second-order differential waveform is obtained by performing a second differentiation process on the positive component or the negative component of the acquired first-order differential waveform. Here, the shape of the portion corresponding to the abnormal portion in the shape of the magnetic flux waveform has one of the shapes of rising to the right and falling to the right according to the type of the abnormal portion (such as wire breakage, kinking, rusting, attachment of foreign matter, etc.). Therefore, the waveform corresponding to the abnormal portion in the first-order differential waveform is included in either the positive component or the negative component according to the type of the abnormal portion. For example, when the abnormal portion is a wire break, the shape of the waveform corresponding to the abnormal portion is rising to the right. Thus, when the abnormal portion is a wire break, the waveform of the portion corresponding to the abnormal portion in the first-order differential waveform is only included in the positive component of the first-order differential waveform. In contrast, in the first embodiment, a second-order differential waveform is obtained by performing a second differentiation process on the positive component or the negative component of the acquired first-order differential waveform. Therefore, it is possible to perform the second differentiation process only on the positive component or the negative component extracted in a manner corresponding to the type of the abnormal portion. Therefore, it is possible to perform the second differentiation process in a state where the waveform of the component that does not include the abnormal portion but only includes noise is eliminated. Moreover, in the first embodiment, as described above, an added waveform is generated by adding the absolute value of the negative component of the acquired second-order differential waveform to the positive component of the acquired second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal portion of the wire rope W coincide. Thus, based on the second-order differential waveform obtained in a state where the waveform of the component that does not include the abnormal portion but only includes noise is eliminated, the absolute value of the negative component of the second-order differential waveform is added to the positive component of the second-order differential waveform in a manner such that the portions representing the abnormal portion of the wire rope W coincide, thereby generating an added waveform. Therefore, it is possible to generate an added waveform in such a way that the portion corresponding to the abnormal portion has a large peak and is more prominent than the noise other than the abnormal portion. As a result, it is possible to distinguish between the noise inherent in the wire rope W and the abnormal portion of the wire rope W by determining the peak of the added waveform. As a result, it is possible to accurately determine the abnormal portion of the wire rope W by distinguishing between the noise inherent in the wire rope W and the abnormal portion of the wire rope W.

[0097] In addition, in the first embodiment, by being configured as follows, further effects as described below can be obtained.

[0098] That is, in the first embodiment, it includes step 607 of performing first differentiation processing on the magnetic flux waveform successively along the time axis based on a prescribed first differentiation interval dt1, and includes step 609 of performing second differentiation processing on the positive component or negative component of the first-order differentiation waveform obtained by successively performing the first differentiation processing along the time axis based on a prescribed second differentiation interval dt2. According to such a structure, by successively performing the first differentiation processing based on the prescribed first differentiation interval dt1 and successively performing the second differentiation processing based on the prescribed second differentiation interval dt2, it is possible to easily obtain a second-order differentiation waveform in a wide range. Therefore, it is possible to easily generate an addition waveform in a wide range based on the obtained second-order differentiation waveform. Thus, by determining the peaks of the addition waveform, it is possible to easily and highly accurately determine the abnormal portion of the wire rope W in a wide range.

[0099] In addition, in the first embodiment, it includes step 607 of successively performing first differentiation processing along the time axis based on a first differentiation interval dt1 set according to the abnormal waveform, and includes step 609 of successively performing second differentiation processing along the time axis based on a second differentiation interval dt2 set according to the abnormal waveform, where the abnormal waveform is a signal waveform representing the abnormal portion of the wire rope W obtained in advance. According to such a structure, the first differentiation interval dt1 and the second differentiation interval dt2 are respectively set based on the abnormal waveform obtained in advance. Therefore, it is possible to obtain a more appropriate second-order differentiation waveform for determining the abnormal portion by performing the first differentiation processing based on the first differentiation interval dt1 and the second differentiation processing based on the second differentiation interval dt2. Thus, the peaks of the abnormal portion in the addition waveform generated based on the second-order differentiation waveform can be made more prominent, and therefore the abnormal portion of the wire rope W can be determined with higher accuracy.

[0100] In addition, in the first embodiment, before step 610 of generating the addition waveform, it includes step 606 of presetting a shift amount D for generating the addition waveform based on the abnormal waveform which is a signal waveform representing the abnormal portion of the wire rope W obtained in advance. In step 610 of generating the addition waveform, the addition waveform is generated by adding the absolute value of the negative component of the second-order differentiation waveform, which is one of the absolute values of the positive component and the negative component of the second-order differentiation waveform, to the positive component of the second-order differentiation waveform in a state where it is shifted along the time axis based on the preset shift amount D. According to such a structure, the shift amount D for generating the addition waveform is preset based on the abnormal waveform which is a signal waveform representing the abnormal portion obtained in advance. Therefore, compared with the case of calculating an appropriate shift amount D based on the generated addition waveform, it is possible to easily generate an addition waveform for determining the abnormal portion.

[0101] In addition, in the first embodiment, before the step 609 of obtaining the second-order differential waveform, there is a step 608 of extracting either the positive component or the negative component of the first-order differential waveform based on the shape of the magnetic flux waveform. According to such a structure, the shape of the abnormal waveform indicating the abnormal part is one of rising to the right and falling to the right according to the type of the abnormal part. Therefore, by distinguishing between the part where the shape of the magnetic flux waveform rises to the right and the part where it falls to the right, it is possible to easily extract from the magnetic flux waveform the part corresponding to each type of abnormal part. Therefore, it is possible to easily extract the positive component or the negative component of the first-order differential waveform corresponding to the type of the abnormal part. Thus, it is possible to easily obtain the second-order differential waveform in a state where the component of the waveform that does not include the abnormal part but only includes noise has been eliminated. As a result, it is possible to easily obtain the addition waveform for determining the abnormality of the wire rope W, and thus it is possible to accurately and easily determine the abnormal part of the wire rope W.

[0102] [Second Embodiment]

[0103] Refer to Figure 14 and Figure 15 to describe the structure of the wire rope inspection system 200 according to the second embodiment. Different from the first embodiment in which the addition waveform is generated based on the preset shift amount D, in this second embodiment, an appropriate shift amount D200 is set (calculated) from a specified shift amount change range (Dmin to Dmax). In addition, in the figure, parts having the same structure as those of the above first embodiment are denoted by the same reference numerals for illustration, and the description thereof is omitted.

[0104] (Structure of the Wire Rope Inspection System According to the Second Embodiment)

[0105] As Figure 14 shown, the wire rope inspection system 200 according to the second embodiment includes a wire rope inspection device 101 and a processing device 202. The detection of the change in the magnetic flux of the wire rope W performed by the wire rope inspection device 101 is the same as that in the first embodiment.

[0106] The processing device 202 includes a control unit 250, a storage unit 260, a touch panel 70, and a communication unit 80. Similar to the processing device 102 in the first embodiment, the processing device 202 executes the process of determining the abnormal part of the wire rope W based on the measurement result of the wire rope W by the wire rope inspection device 101. In addition, similar to the storage unit 60 in the first embodiment, the storage unit 260 stores (saves) information such as the measurement result of the wire rope W and the determination result of the abnormal part. Moreover, in the second embodiment, the storage unit 260 stores a program 261 for determining the abnormal part of the wire rope W and a processing parameter 262.

[0107] (Determination process for abnormal part performed by processing device)

[0108] The control unit 250 includes an addition processing unit 256. Specifically, the control unit 250 as hardware is configured to include the addition processing unit 256 as a functional block of software (program 261). The control unit 250 is configured to execute a process of determining an abnormal part of the wire rope W based on the acquired detection signal by executing the program 261. Other configurations of the control unit 250 are the same as those in the first embodiment.

[0109] That is, the control unit 250 performs a second-order differential process on the magnetic flux waveform, which is a signal waveform based on the acquired detection signal, twice by executing the same control process as in the first embodiment, thereby obtaining a second-order differential waveform. The first differential interval dt1 and the second differential interval dt2, which are the same as those in the first embodiment, are stored in the storage unit 260 as processing parameters 262. On the other hand, in the second embodiment, different from the first embodiment, the processing parameter 262 stored in advance does not include a shift amount.

[0110] As Figure 15 shown, in the second embodiment, the addition processing unit 256 (control unit 250) is configured to set (calculate) a shift amount D200 for generating an addition waveform from a specified shift amount change range (Dmin to Dmax), where the addition waveform is used for the determination process. Specifically, the addition processing unit 256 adds the absolute value of the negative component of the acquired second-order differential waveform to the positive component of the acquired second-order differential waveform in a state where the absolute value is shifted along the time axis while changing the shift amount within the specified shift amount change range (Dmin to Dmax), thereby generating a plurality of pre-addition waveforms. The specified shift amount change range is, for example, 0 [ms] or more and 30 [ms] or less. That is, Dmin is 0 [ms] and Dmax is 30 [ms]. The addition processing unit 256 generates a plurality of (31) pre-addition waveforms while changing the shift amount by 1 [ms] each time within the range of 0 [ms] to 30 [ms]. The process of generating the pre-addition waveforms is the same as the addition process performed by the addition processing unit 56 in the first embodiment. In addition, Figure 15 five pre-addition waveforms among the plurality of pre-addition waveforms are illustrated.

[0111] Then, the addition processing unit 256 obtains the maximum value of the generated multiple pre-added waveforms. Then, the addition processing unit 256 selects, from the multiple pre-added waveforms, the pre-added waveform with the maximum value obtained being the largest. In addition, the addition processing unit 256 sets, from the shift amount change range (Dmin to Dmax), the shift amount that generated the pre-added waveform with the largest maximum value as the shift amount D200 for determining the abnormal portion. Moreover, in the second embodiment, the addition processing unit 256 is configured to: generate an added waveform by adding the absolute value of the negative component of the obtained second-order differential waveform to the positive component of the second-order differential waveform in a state where the negative component is shifted along the time axis based on the set shift amount D200 such that the portion representing the abnormal portion of the wire rope W coincides.

[0112] That is, the addition processing unit 256 is configured to: select, from the shift amount change range (Dmin to Dmax), the shift amount D200 for determining the abnormal portion in such a way that the portion representing the abnormal portion of the wire rope W in the added waveform coincides. In addition, the addition processing unit 256 performs the process of setting the shift amount D200 from the shift amount change range (Dmin to Dmax) for each prescribed interval (for example, every 1 [m]) of the length of the wire rope W.

[0113] Furthermore, the determination process for the abnormal portion of the added waveform generated based on the set shift amount D200 is the same as the determination process of the first embodiment. In addition, the other structure of the second embodiment is the same as the above first embodiment.

[0114] (Effect of the second embodiment)

[0115] In the second embodiment, the following effects can be obtained.

[0116] In the second embodiment, before generating the addition waveform, by adding the absolute value of the negative component of the obtained second-order differential waveform to the positive component of the obtained second-order differential waveform, with the absolute value of the negative component of the second-order differential waveform being shifted along the time axis while varying the shift amount within a specified shift amount change range (Dmin to Dmax), multiple pre-addition waveforms are generated. Then, the addition waveform is generated by adding the absolute value of the negative component of the second-order differential waveform, which is one of the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform, to the positive component of the second-order differential waveform in a state where the absolute value is shifted along the time axis based on the shift amount D200 of the pre-addition waveform with the maximum value being the largest such that the portion representing the abnormal portion of the wire rope W coincides. Here, the pre-addition waveform with the largest maximum value is the pre-addition waveform with the largest maximum value obtained based on each of the multiple generated pre-addition waveforms. According to such a configuration, the addition waveform is generated based on the shift amount D200 of the pre-addition waveform with the largest maximum value obtained based on each of the multiple pre-addition waveforms. Therefore, when adding the positive component of the second-order differential waveform to the absolute value of the negative component to determine the abnormality of the wire rope W, the shift amount D200 for generating the addition waveform can be set more appropriately such that the portion corresponding to the abnormal portion (the portion representing the abnormal portion) has a larger peak. Thus, compared to the case of generating the addition waveform based on a single pre-set shift amount, the inherent noise of the wire rope W can be distinguished from the abnormal portion of the wire rope W with higher accuracy. As a result, the abnormal portion of the wire rope W can be determined with higher accuracy.

[0117] In addition, other effects of the second embodiment are the same as those of the first embodiment described above.

[0118] [Third Embodiment]

[0119] Refer to Figure 16 and Figure 17 to describe the structure of the wire rope inspection system 300 of the third embodiment. Different from the first and second embodiments that directly obtain the magnetic flux waveform by (performing a moving average process) on the detection signal detected by the detection unit 30, this third embodiment generates the magnetic flux waveform based on the difference between the detection signal F1(t) and a previously obtained reference detection signal F0(t). In addition, in the figure, parts having the same structure as those of the first and second embodiments are denoted by the same reference numerals and illustrated, and the description thereof is omitted.

[0120] (Structure of the Wire Rope Inspection System of the Third Embodiment)

[0121] As Figure 16As shown, the wire rope inspection system 300 of the third embodiment includes a wire rope inspection device 101 and a processing device 302. The detection of the change in the magnetic flux of the wire rope W performed by the wire rope inspection device 101 is the same as that in the first embodiment.

[0122] The processing device 302 includes a control unit 350, a storage unit 360, a touch panel 70, and a communication unit 80. Similar to the processing device 102 of the first embodiment, the processing device 302 executes a process of determining an abnormal portion of the wire rope W based on the measurement result of the wire rope W by the wire rope inspection device 101. In addition, similar to the storage unit 60 of the first embodiment, the storage unit 360 stores (saves) information such as the measurement result of the wire rope W and the determination result of the abnormal portion. Moreover, in the third embodiment, the storage unit 360 stores a program 361 for determining an abnormal portion of the wire rope W and a reference detection signal F0(t).

[0123] The reference detection signal F0(t) is a reference detection signal obtained by previously detecting the change in the magnetic flux of the wire rope W to be inspected. For example, the reference detection signal F0(t) is detected by the wire rope inspection device 101 before an abnormal portion is generated (in a state where there are few abnormal portions), such as when the wire rope W is installed. In addition, in the case where multiple (4) wire ropes W are installed as in the elevator 103, the reference detection signal F0(t) of each wire rope among the multiple wire ropes W is stored in the storage unit 360 in advance. Further, the reference detection signal F0(t) is stored in association with the position information of the wire rope W.

[0124] (Determination process of abnormal portion performed by the processing device)

[0125] The control unit 350 includes a waveform generation unit 351. Specifically, the control unit 350 as hardware is configured to include the waveform generation unit 351 as a functional block of software (program 361). The control unit 350 is configured to execute a process of determining an abnormal portion of the wire rope W based on the acquired detection signal by executing the program 361. The other structure of the control unit 350 is the same as that of the first embodiment.

[0126] As Figure 17As shown, the detection signal detected for determining an abnormal portion is represented as F1(t) with respect to the reference detection signal F0(t) pre-stored in the storage unit 60. In the third embodiment, the waveform generation unit 351 (control unit 350) generates a magnetic flux waveform (differential waveform) based on the difference (F1(t) - F0(t)) between the reference detection signal F0(t) and the acquired detection signal F1(t) to cancel out the noise inherent in the wire rope W (change in inherent magnetic characteristics). In the generated magnetic flux waveform, the abnormal portion of the wire rope W is the extracted waveform. Further, the waveform generation unit 351 is configured to: acquire the difference at substantially the same position of the reference detection signal F0(t) and the detection signal F1(t) based on the position information of the wire rope W, thereby generating a magnetic flux waveform. Additionally, similar to the first embodiment, the waveform generation unit 351 generates a magnetic flux waveform by acquiring the difference between the reference detection signal F0(t) and the detection signal F1(t) in a state where a moving average process has been performed.

[0127] Further, the two differential processes, the addition process for generating an addition waveform, and the determination process for the abnormal portion performed on the generated magnetic flux waveform (differential waveform) are the same as those in the first embodiment. Additionally, the other configurations of the third embodiment are the same as those of the first embodiment described above.

[0128] (Effect of the Third Embodiment)

[0129] In the third embodiment, the following effects can be obtained.

[0130] In the third embodiment, before obtaining the first-order differential waveform, a magnetic flux waveform is generated based on the difference between the reference detection signal F0(t) and the acquired detection signal F1(t), where the reference detection signal F0(t) is a reference detection signal obtained by previously detecting the change in the magnetic flux of the wire rope W to be inspected. According to such a configuration, in the previously acquired reference detection signal F0(t) and the detection signal F1(t) detected for determining an abnormal portion, the noise inherent in the wire rope W is common. Therefore, it is possible to generate a magnetic flux waveform in a state where the noise inherent in the detection signal F1(t) is canceled and suppressed (eliminated) by acquiring the difference between the reference detection signal F0(t) and the detection signal F1(t). Thus, it is possible to generate an addition waveform by performing two differential processes on the magnetic flux waveform in a state where the noise is suppressed, and thus it is possible to further suppress the noise in the addition waveform. As a result, it is possible to determine the abnormal portion of the wire rope W with higher accuracy.

[0131] Further, the other effects of the third embodiment are the same as those of the first embodiment and the second embodiment described above.

[0132] [Fourth Embodiment]

[0133] Refer to Figure 18 and Figure 19 to describe the structure of the wire rope inspection system 400 according to the fourth embodiment. Different from the first embodiment configured to extract either the positive component or the negative component of the first-order differential waveform based on the shape of the magnetic flux waveform, the fourth embodiment is configured to extract the positive component or the negative component of the first-order differential waveform by determining whether the value based on the first-order differential waveform is greater than a specified extraction determination threshold S400. In addition, in the figures, parts having the same structure as those in the above first to third embodiments are denoted by the same reference numerals and illustrated, and the description thereof is omitted.

[0134] (Structure of the Wire Rope Inspection System According to the Fourth Embodiment)

[0135] As Figure 18 shown, the wire rope inspection system 400 according to the fourth embodiment includes a wire rope inspection device 101 and a processing device 402. The detection of the change in the magnetic flux of the wire rope W performed by the wire rope inspection device 101 is the same as that in the first embodiment.

[0136] The processing device 402 includes a control unit 450, a storage unit 460, a touch panel 70, and a communication unit 80. Similar to the processing device 102 in the first embodiment, the processing device 402 executes a process of determining an abnormal portion of the wire rope W based on the measurement result of the wire rope W by the wire rope inspection device 101. In addition, similar to the storage unit 60 in the first embodiment, the storage unit 460 stores (saves) information such as the measurement result of the wire rope W and the determination result of the abnormal portion. Moreover, in the fourth embodiment, the storage unit 460 stores a program 461 for determining an abnormal portion of the wire rope W and a processing parameter 462.

[0137] (Determination Process of Abnormal Portion Performed by the Processing Device)

[0138] The control unit 450 includes an extraction processing unit 452. Specifically, the control unit 450 as hardware is configured to include the extraction processing unit 452 as a functional block of software (program 461). The control unit 450 is configured to execute a process of determining an abnormal portion of the wire rope W based on the acquired detection signal by executing the program 461. The other structure of the control unit 450 is the same as that in the first embodiment.

[0139] The control unit 450 generates a magnetic flux waveform through the same control process as in the first embodiment. Moreover, in the fourth embodiment, the control unit 450 is configured to perform a first differentiation process on the generated magnetic flux waveform before determining the type of the abnormal portion. In the fourth embodiment, the processing parameter 462 stored in the storage unit 460 includes a first differentiation interval dt401, a second differentiation interval dt2, and a shift amount D. In the fourth embodiment, the first differentiation interval dt401 is a value shared regardless of the type of the abnormal portion (for example, 20 [ms]). Regarding the second differentiation interval dt2 and the shift amount D, similarly to the first embodiment, they are set based on the abnormal waveforms representing the abnormal portions obtained in advance for each type of the abnormal portion (wire breakage and kink), and are stored in the storage unit 460.

[0140] The first differentiation processing unit 54 of the control unit 450 performs the same process as in the first embodiment to sequentially perform the first differentiation process based on the prescribed first differentiation interval dt401 on the whole of the generated magnetic waveform along the time axis, thereby obtaining a first-order differential waveform.

[0141] Moreover, as Figure 19 shown, in the fourth embodiment, the extraction processing unit 452 (control unit 450) is configured to extract either the positive component or the negative component of the first-order differential waveform based on the comparison between the value of the first-order differential waveform and the prescribed extraction determination threshold S400 before obtaining the second-order differential waveform. That is, the extraction processing unit 452 is configured to separately extract, based on the comparison with the prescribed extraction determination threshold S400, the portion of the first-order differential waveform that is presumed to be the abnormal portion of wire breakage and the portion that is presumed to be the abnormal portion of kink.

[0142] For example, the extraction processing unit 452 extracts a portion where the value of the first-order differential waveform is greater than a specified extraction determination threshold S400 as an abnormal portion presumably indicating a wire break. Further, the second-order differential processing unit 55 of the control unit 450 is configured to obtain a second-order differential waveform for determining an abnormal portion of the wire break by performing a process of extracting a positive component on a portion of the first-order differential waveform presumably indicating an abnormal portion of the wire break and then performing a second-order differential process. Additionally, the extraction processing unit 452 extracts a portion where the value of the first-order differential waveform is less than the specified extraction determination threshold S400 as an abnormal portion presumably indicating a kink. Moreover, the second-order differential processing unit 55 of the control unit 450 is configured to obtain a second-order differential waveform for determining an abnormal portion of the kink by performing a process of extracting a negative component on a portion of the first-order differential waveform presumably indicating an abnormal portion of the kink and then performing a second-order differential process. Furthermore, the process of obtaining a sum waveform from each of the obtained second-order differential waveforms and the process of determining an abnormal portion are the same as those in the first embodiment. Additionally, other configurations of the fourth embodiment are the same as those of the above-described first embodiment.

[0143] (Effects of the Fourth Embodiment)

[0144] In the fourth embodiment, the following effects can be obtained.

[0145] In the fourth embodiment, before obtaining the second-order differential waveform, based on the comparison between the value of the first-order differential waveform and the specified extraction determination threshold S400, one of the positive and negative components of the first-order differential waveform is extracted. With such a configuration, by using the specified extraction determination threshold S400, it is possible to easily distinguish a portion corresponding to an abnormal portion from the first-order differential waveform. Therefore, by using the extraction determination threshold S400, it is possible to easily extract the positive or negative component of the first-order differential waveform in a manner corresponding to the type of abnormal portion. As a result, it is possible to easily obtain the second-order differential waveform in a state where the waveform that does not contain an abnormal portion but only contains noise components has been eliminated. Consequently, it is possible to easily obtain a sum waveform for determining an abnormality of the wire rope W, and thus it is possible to determine an abnormal portion of the wire rope W with high accuracy and easily.

[0146] In addition, other effects of the fourth embodiment are the same as those of the first to third embodiments described above.

[0147] [Modification Example]

[0148] Furthermore, it should be considered that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is shown by the claims rather than by the description of the above embodiments, and also includes all changes (modification examples) within the meaning and scope equivalent to the claims.

[0149] For example, in the first to fourth embodiments described above, an example is shown in which the wire rope inspection device 101 for detecting changes in the magnetic flux of the wire rope W and the processing device 102 (202, 302, 402) for performing the process of determining the abnormal part are configured separately, but the present invention is not limited to this. In the present invention, it may also be configured as in the Figure 20 wire rope inspection device 500 of the modified example shown: the detection of changes in the magnetic flux of the wire rope W and the process of determining the abnormal part are performed using one (shared) wire rope inspection device 500. Specifically, the wire rope inspection device 500 includes a magnetic field shaping unit 10, an exciting unit 20, and a detection unit 30 in the same manner as the wire rope inspection device 101 of the first embodiment. In addition, the wire rope inspection device 500 includes a processing unit 550. The processing unit 550 includes a waveform generation unit 551, an extraction processing unit 552, a parameter setting unit 553, a first differential processing unit 554, a second differential processing unit 555, an addition processing unit 556, and a determination processing unit 557. The waveform generation unit 551, the extraction processing unit 552, the parameter setting unit 553, the first differential processing unit 554, the second differential processing unit 555, the addition processing unit 556, and the determination processing unit 557 are the same as the waveform generation unit 51, the extraction processing unit 52, the parameter setting unit 53, the first differential processing unit 54, the second differential processing unit 55, the addition processing unit 56, and the determination processing unit 57 of the control unit 50 of the first embodiment, respectively. That is, the wire rope inspection device 500 is configured to perform the process of determining the abnormal part of the wire rope W based on the detection signal obtained by the detection unit 30 in the same manner as the control unit 50 of the processing device 102 of the first embodiment. In addition, in the wire rope inspection device 500 of the modified example, similar to the wire rope inspection systems 100 (200, 300, 400) of the first to fourth embodiments, the abnormal part of the wire rope W can be determined with high accuracy by distinguishing the inherent noise of the wire rope W from the abnormal part of the wire rope W.

[0150] In addition, in the first to fourth embodiments described above, an example is shown in which the processing device 102 (202, 302, 402) is a tablet PC used by an inspection operator, but the present invention is not limited to this. For example, the processing device that performs the determination process of the abnormal part may also be a remotely installed device such as a server device. That is, it may also be configured to obtain the measurement result of the wire rope inspection device 101 using the remotely installed processing device and perform the determination of the abnormal part at a position far from the elevator 103 (wire rope W).

[0151] In addition, in the above-described first to third embodiments, an example is shown in which the first differential interval dt1 is set to 15 [ms] and the second differential interval dt2 is set to 7 [ms] based on an abnormal waveform that is a signal waveform representing an abnormal portion of the wire rope W obtained in advance. However, the present invention is not limited thereto. For example, the first differential interval dt1 and the second differential interval dt2 may also be set based on an input operation performed by an inspection operator. In addition, the first differential interval dt1 set based on the abnormal waveform is not limited to 15 [ms], and the second differential interval dt2 set based on the abnormal waveform is not limited to 7 [ms].

[0152] In addition, in the above-described first to third embodiments, an example is shown in which the length of the second differential interval dt2 is approximately half the length of the first differential interval dt1. However, the present invention is not limited thereto. For example, the length of the second differential interval dt2 may also be set to be substantially equal to the length of the first differential interval dt1.

[0153] In addition, in the above-described first, third, and fourth embodiments, an example is shown in which the shift amount D is set to 20 [ms] based on an abnormal waveform that is a signal waveform representing an abnormal portion of the wire rope W obtained in advance. However, the present invention is not limited thereto. For example, the shift amount D may also be set based on an input operation performed by an inspection operator. In addition, the shift amount D set based on the abnormal waveform is not limited to 20 [ms].

[0154] In addition, in the above-described first and third embodiments, an example is shown in which the shift amount D is a value greater than the first differential interval dt1. However, the present invention is not limited thereto. For example, the shift amount D may also be set to a value smaller than the first differential interval dt1.

[0155] In addition, in the above-described second embodiment, an example is shown in which the specified shift amount change range (Dmin to Dmax) is 0 [ms] or more and 30 [ms] or less. However, the present invention is not limited thereto. For example, the minimum value Dmin of the shift amount change range may also be a value other than 0 [ms], and the maximum value Dmax may also be a value other than 30 [ms].

[0156] In addition, in the above-described first to third embodiments, an example is shown in which the type of the abnormal portion is determined by distinguishing based on the shape of the generated magnetic waveform. In the above-described fourth embodiment, an example is shown in which the type of the abnormal portion is determined by distinguishing based on the comparison between the value of the first-order differential waveform and a specified extraction determination threshold S400. However, the present invention is not limited thereto. For example, control for determining the type of the abnormal portion may not be performed on the magnetic flux waveform or the first-order differential waveform. Specifically, it may be configured to preset the type of the abnormal portion to be determined based on an input operation performed by an inspection operator, and extract either the positive component or the negative component of the first-order differential waveform based on the preset type of the abnormal portion.

[0157] In addition, in the above-described fourth embodiment, an example is shown in which it is determined which of the positive component and the negative component of the first-order differential waveform is to be extracted by determining whether it is greater than one extraction determination threshold S400. However, the present invention is not limited thereto. For example, a plurality of specified extraction determination thresholds may be set in a manner corresponding to the type of the abnormal portion. Specifically, it may be to obtain a portion where the value of the first-order differential waveform is greater than a first threshold as a portion of the abnormal portion presumed to be a wire break, and obtain a portion where the value of the first-order differential waveform is less than a second threshold different from the first threshold as a portion of the abnormal portion presumed to be a kink. In addition, the specified extraction determination threshold S400 may be 0, for example. That is, it may be to set a portion where the value of the first-order differential waveform is positive as a portion of the abnormal portion for determining a wire break, and set a portion where the first-order differential waveform is negative as a portion of the abnormal portion for determining a kink.

[0158] In addition, in the above-described first to fourth embodiments, an example is shown in which the types of the abnormal portions to be determined are two types, namely, wire break and kink. However, the present invention is not limited thereto. For example, attachment of foreign matters such as iron powder or rust may be determined as an abnormal portion instead of a kink. In addition, it may be configured to determine abnormal portions of more than two types. In addition, determination of only one type of abnormal portion may be performed.

[0159] In addition, in the above-described first to fourth embodiments, an example is shown in which a moving average process is performed within a range of 10 sampling points (20 [ms]) before and after each sampling for the magnetic flux waveform which is a signal waveform based on the acquired detection signal. However, the present invention is not limited thereto. The range of the moving average process may also be a range other than 20 [ms]. In addition, the moving average process may not be performed when generating the magnetic flux waveform. In addition, noise removal processing other than the moving average process, such as low-pass filtering processing, may be performed to generate the magnetic flux waveform.

[0160] In addition, in the above-described first to fourth embodiments, an example of inspecting the wire rope W of the elevator 103 is shown, but the present invention is not limited thereto. For example, it may be configured to inspect the wire ropes of equipment other than elevators, such as cranes and cableways.

[0161] In addition, in the above-described first to fourth embodiments, an example is shown in which the two detection coils 31a and 31b of the detection unit 30 are independent saddle-shaped coils (saddle type coils), but the present invention is not limited thereto. For example, the detection unit 30 may also be a set of solenoid coils that are arranged to wind around the wire rope W and are differentially connected.

[0162] In addition, in the above-described first to fourth embodiments, an example is shown in which the excitation coil 21 is wound outside the detection coils 31a and 31b with respect to the wire rope W, but the present invention is not limited thereto. For example, the excitation unit 20 and the detection unit 30 may also be arranged side by side along the extending direction of the wire rope W.

[0163] In addition, in the above-described first to fourth embodiments, an example is shown in which the magnetic flux adjusting portions 10a and 10b that are arranged to face each other with the wire rope W interposed therebetween are respectively configured such that the N poles face the wire rope W side, but the present invention is not limited thereto. For example, the two magnetic flux adjusting portions may be configured such that the N pole and the S pole face the wire rope W, respectively. Alternatively, the two magnetic flux adjusting portions may be configured such that the N pole and the S pole are arranged not in the direction of facing each other but in the extending direction of the wire rope W. In this case, the two magnetic flux adjusting portions may have the same orientation or different orientations. Alternatively, the magnetic flux adjusting portion may be configured to apply a magnetic field in an orientation that is inclined and offset with respect to the orientation parallel to the extending direction of the wire rope W. Alternatively, one magnetic flux adjusting portion may be arranged on one side in a direction intersecting the extending direction of the wire rope W. Alternatively, the magnetic flux adjusting portion may not be provided and the magnetic flux may be detected without adjusting the magnetic field.

[0164] In addition, in the above-described first to fourth embodiments, an example is shown in which the magnetic flux adjusting portion 10 is constituted by a permanent magnet, but the present invention is not limited thereto. For example, the magnetic flux adjusting portion may also be constituted by an electromagnet.

[0165] In addition, in the above-described first to fourth embodiments, an example is shown in which the detection coils 31a and 31b are provided for each of the four wire ropes W, but the present invention is not limited thereto. For example, the detection coil may be configured to detect the magnetic flux of one or more and three or fewer wire ropes W, or may be configured to detect the magnetic flux of five or more wire ropes W. Alternatively, it may be configured to detect the magnetic flux of multiple wire ropes W using one detection coil.

[0166] [Mode]

[0167] Those skilled in the art can understand that the above exemplary embodiments are specific examples of the following methods.

[0168] (Item 1)

[0169] A wire rope inspection method, comprising the following steps:

[0170] Apply a magnetic field to the wire rope to be inspected;

[0171] Obtain a detection signal by detecting a change in the magnetic flux of the wire rope to which the magnetic field is applied while relatively moving the detection unit with respect to the wire rope;

[0172] Obtain a first-order differential waveform by performing a first differential process on the magnetic flux waveform, where the magnetic flux waveform is based on the signal waveform of the obtained detection signal;

[0173] Obtain a second-order differential waveform by performing a second differential process on the positive component or the negative component of the obtained first-order differential waveform;

[0174] Generate an added waveform by adding the positive component of the obtained second-order differential waveform and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the parts representing the abnormal part of the wire rope overlap; and

[0175] When the value based on the generated added waveform is greater than a specified determination threshold, determine the abnormal part of the wire rope.

[0176] (Item 2)

[0177] According to the wire rope inspection method described in Item 1, wherein,

[0178] The step of obtaining the first-order differential waveform includes the following steps: performing the first differential process on the magnetic flux waveform along the time axis in sequence based on a specified first differential interval,

[0179] The step of obtaining the second-order differential waveform includes the following steps: performing the second differential process on the positive component or the negative component of the first-order differential waveform obtained by sequentially performing the first differential process along the time axis in sequence based on a specified second differential interval.

[0180] (Item 3)

[0181] According to the wire rope inspection method described in Item 2, wherein,

[0182] The steps of sequentially performing the first differentiation processing along the time axis include the following steps: sequentially performing the first differentiation processing based on the first differentiation interval set according to the abnormal waveform along the time axis, where the abnormal waveform is a signal waveform obtained in advance representing the abnormal part of the wire rope.

[0183] The steps of sequentially performing the second differentiation processing along the time axis include the following steps: sequentially performing the second differentiation processing based on the second differentiation interval set according to the abnormal waveform along the time axis.

[0184] (Item 4)

[0185] According to the wire rope inspection method described in any one of Items 1 to 3, where

[0186] Before the step of generating the added waveform, the following steps are further included: based on the abnormal waveform which is a signal waveform obtained in advance representing the abnormal part of the wire rope, preset the shift amount for generating the added waveform.

[0187] The step of generating the added waveform includes the following steps: generate the added waveform by adding one of the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform to the other in a state where one of them is shifted along the time axis based on the preset shift amount.

[0188] (Item 5)

[0189] According to the wire rope inspection method described in any one of Items 1 to 3, where

[0190] Before the step of generating the added waveform, the following steps are included: generate a plurality of pre-added waveforms by adding one of the positive component of the obtained second-order differential waveform and the absolute value of the negative component of the obtained second-order differential waveform to the other in a state where the shift amount is changed within a specified shift amount change range while one of them is shifted along the time axis.

[0191] The step of generating the added waveform includes the following steps: add one of the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform to the other in a state where one of them is shifted along the time axis based on the shift amount of the pre-added waveform with the largest maximum value such that the part representing the abnormal part of the wire rope overlaps, to generate the added waveform, where the pre-added waveform with the largest maximum value is the pre-added waveform based on the maximum value of each of the plurality of generated pre-added waveforms being the largest.

[0192] (Item 6)

[0193] The wire rope inspection method according to any one of Items 1 to 5, wherein,

[0194] Before the step of obtaining the first-order differential waveform, the following steps are further included: generating the magnetic flux waveform based on the difference between the reference detection signal and the obtained detection signal, wherein the reference detection signal is a reference detection signal obtained by pre-detecting the change in the magnetic flux of the wire rope to be inspected.

[0195] (Item 7)

[0196] The wire rope inspection method according to any one of Items 1 to 6, wherein,

[0197] Before the step of obtaining the second-order differential waveform, the following steps are further included: extracting one of the positive component and the negative component of the first-order differential waveform based on the shape of the magnetic flux waveform.

[0198] (Item 8)

[0199] The wire rope inspection method according to any one of Items 1 to 6, wherein,

[0200] Before the step of obtaining the second-order differential waveform, the following steps are further included: extracting one of the positive component and the negative component of the first-order differential waveform according to the comparison between the value of the first-order differential waveform and a specified extraction determination threshold.

[0201] (Item 9)

[0202] A wire rope inspection system, comprising:

[0203] A wire rope inspection device that detects the change in the magnetic flux of the wire rope to be inspected; and

[0204] A processing device that performs processing for determining an abnormal part of the wire rope based on the measurement result of the wire rope by the wire rope inspection device,

[0205] wherein the wire rope inspection device includes: an excitation part that applies a magnetic field to the wire rope; and a detection part that obtains a detection signal by detecting the change in the magnetic flux of the wire rope to which the magnetic field is applied by the excitation part while relatively moving with the wire rope,

[0206] The processing device includes:

[0207] A first-order differential processing part that obtains a first-order differential waveform by performing a first-order differential processing on the magnetic flux waveform, and the magnetic flux waveform is based on the signal waveform of the detection signal obtained by the detection part;

[0208] A second differential processing unit that obtains a second differential waveform by performing a second differential process on a positive component or a negative component of the first differential waveform obtained by using the first differential processing unit;

[0209] An addition processing unit that generates an addition waveform by adding, in a state where the positive component of the second differential waveform obtained by using the second differential processing unit and the absolute value of the negative component of the obtained second differential waveform are shifted along the time axis so that portions representing the abnormal portion of the wire rope overlap; and

[0210] A determination processing unit that determines the abnormal portion of the wire rope when the value of the addition waveform generated by using the addition processing unit is greater than a prescribed determination threshold value.

[0211] (Item 10)

[0212] A wire rope inspection device, comprising:

[0213] An exciting unit that applies a magnetic field to a wire rope as an inspection object;

[0214] A detection unit that obtains a detection signal by detecting a change in magnetic flux of the wire rope to which the magnetic field is applied by the exciting unit while relatively moving with respect to the wire rope; and

[0215] A processing unit that performs a process of determining an abnormal portion of the wire rope based on the detection signal obtained by using the detection unit,

[0216] wherein the processing unit includes:

[0217] A first differential processing unit that obtains a first differential waveform by performing a first differential process on a magnetic flux waveform, the magnetic flux waveform being a signal waveform based on the detection signal obtained by using the detection unit;

[0218] A second differential processing unit that obtains a second differential waveform by performing a second differential process on a positive component or a negative component of the first differential waveform obtained by using the first differential processing unit;

[0219] An addition processing unit that generates an addition waveform by adding, in a state where the positive component of the second differential waveform obtained by using the second differential processing unit and the absolute value of the negative component of the obtained second differential waveform are shifted along the time axis so that portions representing the abnormal portion of the wire rope overlap; and

[0220] A determination processing unit that determines the abnormal portion of the wire rope when the value of the added waveform generated by the addition processing unit is greater than a specified determination threshold.

Claims

1. A wire rope inspection method, comprising the following steps: Applying a magnetic field to the wire rope to be inspected; Obtaining a detection signal by detecting a change in the magnetic flux of the wire rope to which the magnetic field is applied while relatively moving a detection unit with respect to the wire rope; Obtaining a first-order differential waveform by performing a first differential process on the magnetic flux waveform, where the magnetic flux waveform is based on the signal waveform of the obtained detection signal; Obtaining a second-order differential waveform by performing a second differential process on the positive component or the negative component of the obtained first-order differential waveform; Generating an addition waveform by adding the absolute value of the positive component of the obtained second-order differential waveform and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal part of the wire rope overlap; And Determining the abnormal part of the wire rope when the value of the generated addition waveform is greater than a specified determination threshold.

2. The wire rope inspection method according to claim 1, wherein The step of obtaining the first-order differential waveform includes the following steps: performing the first differential process on the magnetic flux waveform along the time axis in sequence based on a specified first differential interval; The step of obtaining the second-order differential waveform includes the following steps: performing the second differential process on the positive component or the negative component of the first-order differential waveform obtained by performing the first differential process along the time axis in sequence based on a specified second differential interval.

3. The wire rope inspection method according to claim 2, wherein The step of performing the first differential process along the time axis in sequence includes the following steps: performing the first differential process along the time axis in sequence based on the first differential interval set according to an abnormal waveform, where the abnormal waveform is a signal waveform representing the abnormal part of the wire rope obtained in advance; The step of performing the second differential process along the time axis in sequence includes the following steps: performing the second differential process along the time axis in sequence based on the second differential interval set according to the abnormal waveform.

4. The wire rope inspection method according to any one of claims 1 to 3, wherein Before the step of generating the addition waveform, the method further includes the following steps: presetting a shift amount for generating the addition waveform based on an abnormal waveform which is a signal waveform representing the abnormal part of the wire rope obtained in advance; The step of generating the addition waveform includes the following steps: generating the addition waveform by adding one of the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform to the other in a state where the one is shifted along the time axis based on the preset shift amount.

5. The wire rope inspection method according to any one of claims 1 to 3, wherein Before the step of generating the added waveform, the following steps are included: By adding one of the positive component of the obtained second-order differential waveform and the absolute value of the negative component of the obtained second-order differential waveform while changing the shift amount within a specified shift amount change range on one side and shifting the one along the time axis, a plurality of pre-added waveforms are generated. The step of generating the added waveform includes the following steps: Adding one of the positive component of the second-order differential waveform and the absolute value of the negative component of the second-order differential waveform while shifting the one along the time axis based on the shift amount of the pre-added waveform with the maximum value being the largest so that the part representing the abnormal part of the steel wire rope partially overlaps, to generate the added waveform, where the pre-added waveform with the maximum value being the largest is the pre-added waveform based on the maximum value of each of the plurality of generated pre-added waveforms being the largest.

6. The steel wire rope inspection method according to any one of claims 1 to 3, wherein Before the step of obtaining the first-order differential waveform, the following steps are further included: Generating the magnetic flux waveform based on the difference between the reference detection signal and the obtained detection signal, where the reference detection signal is a detection signal obtained by previously detecting the change in the magnetic flux of the steel wire rope to be inspected and serving as a reference.

7. The steel wire rope inspection method according to any one of claims 1 to 3, wherein Before the step of obtaining the second-order differential waveform, the following steps are further included: Extracting one of the positive component and the negative component of the first-order differential waveform based on the shape of the magnetic flux waveform.

8. The steel wire rope inspection method according to any one of claims 1 to 3, wherein Before the step of obtaining the second-order differential waveform, the following steps are further included: Extracting one of the positive component and the negative component of the first-order differential waveform according to the comparison between the value of the first-order differential waveform and a specified extraction determination threshold.

9. A steel wire rope inspection system, comprising: A steel wire rope inspection device that detects the change in the magnetic flux of the steel wire rope to be inspected; and A processing device that executes a process of determining the abnormal part of the steel wire rope based on the measurement result of the steel wire rope by the steel wire rope inspection device. Among them, The steel wire rope inspection device includes: An exciting part that applies a magnetic field to the steel wire rope; and a detection part that obtains a detection signal by detecting the change in the magnetic flux of the steel wire rope to which the magnetic field is applied by the exciting part while relatively moving with the steel wire rope. The processing device includes: A first-order differential processing part that obtains a first-order differential waveform by performing a first-order differential process on the magnetic flux waveform, where the magnetic flux waveform is based on the signal waveform of the detection signal obtained by the detection part. A second-order differential processing part that obtains a second-order differential waveform by performing a second-order differential process on the positive component or the negative component of the first-order differential waveform obtained by the first-order differential processing part. An addition processing unit that generates an addition waveform by adding the positive component of the second-order differential waveform obtained by the second differential processing unit and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal portion of the wire rope overlap; and A determination processing unit that determines the abnormal portion of the wire rope when the value of the addition waveform generated by the addition processing unit is greater than a predetermined determination threshold value.

10. A wire rope inspection device, comprising: An excitation unit that applies a magnetic field to a wire rope to be inspected; A detection unit that obtains a detection signal by detecting a change in the magnetic flux of the wire rope to which a magnetic field is applied by the excitation unit while relatively moving with respect to the wire rope; And A processing unit that performs a process of determining an abnormal portion of the wire rope based on the detection signal obtained by the detection unit, Wherein The processing unit includes: A first differential processing unit that obtains a first-order differential waveform by performing a first differential process on a magnetic flux waveform, the magnetic flux waveform being a signal waveform based on the detection signal obtained by the detection unit; A second differential processing unit that obtains a second-order differential waveform by performing a second differential process on the positive component or the negative component of the first-order differential waveform obtained by the first differential processing unit; An addition processing unit that generates an addition waveform by adding the positive component of the second-order differential waveform obtained by the second differential processing unit and the absolute value of the negative component of the obtained second-order differential waveform in a state where they are shifted along the time axis so that the portions representing the abnormal portion of the wire rope overlap; and A determination processing unit that determines the abnormal portion of the wire rope when the value of the addition waveform generated by the addition processing unit is greater than a predetermined determination threshold value.

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