Detecting device, and detecting method

Abstract

This detecting device comprises: a signal output unit for outputting a measurement signal having a frequency component to a target line having an orientation that changes; a measuring unit for receiving from the target line a response signal including a signal obtained through reflection of the measurement signal, and measuring at least either of an amplitude and a phase of the received response signal; a calculating unit for calculating a plurality of evaluation values corresponding to each of a plurality of the orientations on the basis of measurement results obtained by the measuring unit; and a detecting unit for detecting damage to a portion of the target line on the basis of the plurality of evaluation values calculated by the calculating unit.

Description

Detection device and detection method

[0001] This application claims priority from Japanese Patent Application No. 2024-61369, filed April 5, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0002] Patent Document 1 (JP 2023-44388 A) discloses the following method for estimating the progression of a wire breakage. That is, the method for estimating the progression of a wire breakage in a cable having a conductor made of a stranded conductor formed by twisting together a plurality of wires, measures the resistance of the conductor, which changes over time due to a predetermined operation when the cable is repeatedly subjected to the operation, calculates the maximum, minimum, and average values ​​of the resistance values ​​in the time-series change of the conductor's resistance for each measurement section separated by a time interval equal to or longer than the time required for the operation, and estimates the progression of the wire breakage in the conductor based on the normalized resistance fluctuation range obtained by "normalized resistance fluctuation range = (maximum value - minimum value) / average value."

[0003] JP 2023-44388 A

[0004] The detection device of the present disclosure includes a signal output unit that outputs a measurement signal having a frequency component to a target line; a measurement unit that receives a response signal from the target line that includes a signal reflected from the measurement signal and measures at least one of the amplitude and phase of the received response signal; a calculation unit that calculates a plurality of evaluation values ​​corresponding to a plurality of postures of the target line whose posture changes based on the measurement results by the measurement unit; and a detection unit that detects damage to a portion of the target line based on the plurality of evaluation values ​​calculated by the calculation unit.

[0005] One aspect of the present disclosure may be realized not only as a detection device including such a characteristic processing unit, but also as a program for causing a computer to execute the steps of such characteristic processing. Furthermore, one aspect of the present disclosure may be realized as a semiconductor integrated circuit that realizes part or all of the detection device, or as a system including the detection device.

[0006] FIG. 1 is a diagram illustrating a configuration of a communication system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a transmission line used in the communication system according to the embodiment of the present disclosure. FIG. 3 is a diagram illustrating a bent state of the transmission line used in the communication system according to the embodiment of the present disclosure. FIG. 4 is a diagram illustrating a configuration of a communication device according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of absolute values ​​of reflection coefficients calculated by a processing unit in the communication device according to the embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of change over time in the average value of the absolute values ​​of the reflection coefficients of a core wire. FIG. 7 is a diagram illustrating an example of change over time in the average value of the absolute values ​​of the reflection coefficients of a core wire. FIG. 8 is a diagram illustrating an example of change over time in the average value of the absolute values ​​of the reflection coefficients of a core wire. FIG. 9 is a diagram illustrating an example of change over time in the variance of the absolute values ​​of the reflection coefficients of a core wire. FIG. 10 is a diagram illustrating an example of change over time in the variance of the absolute values ​​of the reflection coefficients of a core wire. FIG. 11 is a diagram illustrating an example of change over time in the average value of the phase difference between a reflected signal and a measurement signal at a core wire. FIG. 12 is a diagram illustrating an example of change over time in the average value of the phase difference between a reflected signal and a measurement signal at a core wire. FIG. 13 is a diagram illustrating an example of a change over time in the variance of the phase difference between a reflected signal and a measurement signal at a core wire. FIG. 14 is a diagram illustrating an example of a change over time in the variance of the phase difference between a reflected signal and a measurement signal at a core wire. FIG. 15 is a diagram illustrating an example of a scatter plot of the impedances of two core wires in a test transmission line. FIG. 16 is a diagram illustrating an example of a scatter plot of the impedances of two core wires in a test transmission line. FIG. 17 is a diagram illustrating an example of a change over time in the regression residuals of the impedances of two core wires in a test transmission line. FIG. 18 is a diagram illustrating an example of a change over time in the regression residuals of the impedances of two core wires in a test transmission line. FIG. 19 is a diagram illustrating an example of a scatter plot of feature quantities of the impedances of core wires in a test transmission line. FIG. 20 is a diagram illustrating an example of a scatter plot of feature quantities of the impedances of core wires in a test transmission line. FIG. 21 is a flowchart defining an example of an operational procedure when a communication device according to an embodiment of the present disclosure performs detection processing.

[0007] Conventionally, techniques for detecting breaks in transmission lines and the like have been proposed.

[0008] [Problem to be Solved by the Present Disclosure] There is a need for a technology that goes beyond the technology described in Patent Document 1 and that is capable of detecting damage to a portion of a target wire with a simple configuration.

[0009] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a detection device and a detection method that are capable of detecting damage to a portion of a target wire with a simple configuration.

[0010] Effect of the Present Disclosure According to the present disclosure, damage to a portion of a target line can be detected with a simple configuration.

[0011] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be listed and described. (1) A detection device according to an embodiment of the present disclosure includes a signal output unit that outputs a measurement signal having a frequency component to a target wire, a measurement unit that receives a response signal from the target wire including a signal reflected from the measurement signal and measures at least one of the amplitude and the phase of the received response signal, a calculation unit that calculates a plurality of evaluation values ​​corresponding to a plurality of postures of the target wire whose posture changes based on the measurement results by the measurement unit, and a detection unit that detects damage to a portion of the target wire based on the plurality of evaluation values ​​calculated by the calculation unit.

[0012] In this way, by outputting a measurement signal to the target line and detecting damage to the target line using multiple evaluation values ​​corresponding to the multiple postures of the target line, which changes in posture, it is possible to accurately detect damage to a portion of the target line by taking into account changes in the electrical characteristics of the target line due to changes in posture of the target line. Furthermore, by outputting a measurement signal to the target line and receiving a response signal including a reflected signal from the target line, it is possible to detect damage to a portion of the target line without requiring a dedicated line separate from the target line. Therefore, it is possible to predict breaks in a transmission line with a simple configuration.

[0013] (2) In the above (1), the detection unit may detect damage to a portion of the target line based on a statistical value of the plurality of evaluation values.

[0014] With this configuration, damage to a portion of the target line can be determined by comprehensively using multiple evaluation values ​​according to the posture of the target line, thereby making it possible to more accurately detect damage to a portion of the target line.

[0015] (3) In the above (2), the detection unit may detect damage to a portion of the target line based on a result of comparing the statistical value with a predetermined threshold value.

[0016] With this configuration, it is possible to detect whether or not a part of the target line is damaged through simple processing.

[0017] (4) In the above (2), the detection unit may detect damage to a portion of the target line based on a change over time in the statistical value.

[0018] With this configuration, damage to the target line can be detected based on changes in the statistical value of the evaluation value of the target line, thereby absorbing individual differences in the electrical characteristics of the target line and more accurately detecting damage to part of the target line.

[0019] (5) In the above (1) to (4), the signal output unit may output the measurement signal to a plurality of the target lines, the measurement unit may receive the response signal from each of the plurality of target lines and measure at least one of the amplitude and phase of each of the received response signals, the calculation unit may calculate the plurality of evaluation values ​​for each of the target lines, and the detection unit may detect damage to a portion of the target line based on the plurality of evaluation values ​​for each of the target lines.

[0020] With this configuration, damage detection can be performed on multiple target lines in parallel.

[0021] (6) In the above (5), the detection unit may detect damage to a part of the target line based on a relationship between the plurality of evaluation values ​​for each of the target lines.

[0022] With this configuration, damage to a portion of the target line can be detected more accurately, for example, based on a change in the evaluation value of a portion of the target lines among a plurality of target lines.

[0023] (7) In the above (6), the detection unit may calculate a feature value indicating the relationship between the evaluation values ​​for each target line based on the multiple evaluation values ​​for each target line, and detect damage to a portion of the target line based on the feature value.

[0024] With this configuration, for example, by noting that the electrical characteristics of multiple bundled normal target lines are highly correlated, damage to part of the target line can be more accurately detected based on the magnitude of correlation between the evaluation values ​​of each target line.

[0025] (8) In the above (7), the detection unit may calculate, as the feature amount, a regression residual of the plurality of evaluation values ​​for each of the target lines.

[0026] With this configuration, damage to a portion of the target line can be detected more accurately based on the magnitude of the feature amount that indicates the deviation of the calculated evaluation value from the predicted evaluation value, for example.

[0027] (9) In the above (7), the detection unit may calculate the feature amount by dimensionally compressing the plurality of evaluation values ​​for each of the target lines.

[0028] This configuration allows for more accurate detection of damage to a portion of the target line, for example, based on deviation of the feature value from a normal numerical range.

[0029] (10) In (6) above, the detection unit may calculate a statistical value of the plurality of evaluation values ​​for each of the target lines, and based on a comparison result of each of the statistical values, identify a target line among the plurality of target lines that is partially damaged.

[0030] This configuration allows for more accurate detection of partial damage to a target line by taking into account the effect of damage to the target line on the electrical characteristics of other target lines. Furthermore, by identifying a target line that is partially damaged, maintenance of the target line can be easily performed.

[0031] (11) In any of (1) to (10) above, the detection device may further include a control unit that controls the attitude of the target line, and may be capable of setting a control pattern for the attitude by the control unit.

[0032] With this configuration, it is possible to set a control pattern depending on the operation of the drive unit of, for example, a robot on which the target wire is mounted, so that damage to part of the target wire can be detected more accurately, for example, in a posture in which the occurrence of damage is likely to be reflected in the evaluation value.

[0033] (12) In any one of (1) to (11) above, the detection unit may further detect a degree of progress of damage to the target line.

[0034] With this configuration, maintenance and replacement of the target line can be carried out in a planned manner based on the degree of progress of damage to the target line.

[0035] (13) The detection method disclosed herein is a detection method in a detection device, and includes the steps of outputting a measurement signal having frequency components to a target line, receiving a response signal from the target line including a signal reflected from the measurement signal, and measuring at least one of the amplitude and phase of the received response signal, calculating a plurality of evaluation values ​​corresponding to a plurality of postures of the target line whose posture changes based on the measurement results of at least one of the amplitude and the phase, and detecting damage to a portion of the target line based on the calculated plurality of evaluation values.

[0036] In this way, by outputting a measurement signal to the target line and detecting damage to the target line using multiple evaluation values ​​corresponding to the multiple postures of the target line, which changes in posture, it is possible to accurately detect damage to a portion of the target line by taking into account changes in the electrical characteristics of the target line due to changes in posture of the target line. Furthermore, by outputting a measurement signal to the target line and receiving a response signal including a reflected signal from the target line, it is possible to detect damage to a portion of the target line without requiring a dedicated line separate from the target line. Therefore, it is possible to predict breaks in a transmission line with a simple configuration.

[0037] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and their description will not be repeated. Furthermore, at least some of the embodiments described below may be combined in any manner.

[0038] [Configuration and Basic Operation] Fig. 1 is a diagram showing the configuration of a communication system according to an embodiment of the present disclosure. Referring to Fig. 1, communication system 301 includes communication devices 101 and 111. Note that communication system 301 may include multiple communication devices 111.

[0039] The communication devices 101 and 111 are connected to each other via a communication transmission line 10. More specifically, the transmission line 10 includes a cable portion and connector portions provided at a first end and a second end of the cable portion, respectively. The connector portion provided at the first end of the cable portion is connected to the communication device 101. The connector portion provided at the second end of the cable portion is connected to the communication device 111. The transmission line 10 is, for example, an Ethernet (registered trademark) cable.

[0040] The communication system 301 is used, for example, in factory automation. More specifically, the communication devices 101 and 111 are mounted on the robot arm of an industrial robot. Note that the communication system 301 may also be used, for example, in robots other than industrial robots, hoist cranes, or machine tools.

[0041] 2 is a diagram illustrating an example of a transmission line used in a communication system according to an embodiment of the present disclosure, showing a cross-sectional view of the transmission line 10 when the transmission line 10 is cut along a plane perpendicular to the longitudinal direction of the transmission line 10.

[0042] Referring to FIG. 2 , the transmission line 10 includes core wires 1A, 1B, 1C, 1D, 1E, and 1F and a sheath 2. Hereinafter, each of the core wires 1A, 1B, 1C, 1D, 1E, and 1F will also be referred to as a core wire 1. The core wire 1 includes a plurality of strands 3 and an insulating layer 4 covering the plurality of strands 3. The plurality of core wires 1 are bundled together by the sheath 2. Therefore, when a load is applied to the transmission line 10, all of the core wires 1 are bent at the same bending angle. An insulator may be filled between the core wires 1 and the sheath 2. For example, the transmission line 10 is a cable including a plurality of twisted pairs in which two core wires 1 are twisted together. Note that the transmission line 10 may also be a cable including a plurality of parallel wires in which two core wires 1 are arranged parallel to each other. The parallel wires may or may not be parallel to each other. The communication devices 101 and 111 are electrically connected via the core wire 1.

[0043] The communication device 101 transmits a communication signal Sc for controlling the robot arm to the communication device 111 via a predetermined core wire 1 in the transmission line 10. The communication device 111 operates the robot arm using an actuator or the like (not shown) in accordance with the communication signal Sc received from the communication device 101. The communication device 111 also transmits a response signal Sr in response to the communication signal Sc and sensor information attached to the robot arm to the communication device 101 via a predetermined core wire 1 in the transmission line 10 that is different from the core wire 1 used to transmit the communication signal Sc. When the communication system 301 includes a plurality of communication devices 111, the core wires 1 in the transmission line 10 may be divided to connect the communication device 101 to the plurality of communication devices 111.

[0044] 3 is a diagram illustrating a state in which a transmission line used in a communication system according to an embodiment of the present disclosure is bent. Hereinafter, the length direction of the transmission line 10 is referred to as the Y direction. FIG. 3 illustrates a state in which the transmission line 10 is bent in the positive X direction in the XY plane.

[0045] 3 , for example, the transmission line 10 is bent in the XY plane at a predetermined bending position Bp in accordance with the operation of a robot arm on which the communication devices 101, 111 are mounted. Hereinafter, the bending angle θ of the transmission line 10 and the core wire 1 in the XY plane will also be referred to as the bending angle θxy. Furthermore, the bending angle θxy when the transmission line 10 and the core wire 1 are bent in the positive X direction will be taken as a positive value, and the bending angle θxy when the transmission line 10 and the core wire 1 are bent in the negative X direction will be taken as a negative value.

[0046] The wires 3 in the core wire 1 may be damaged and broken due to repeated bending of the transmission line 10. Even if some of the wires 3 in the core wire 1 are broken, the electrical connection between the communication devices 101 and 111 is maintained by the remaining unbroken wires 3 in the core wire 1. However, if the damage to the core wire 1 progresses and all of the wires 3 in the core wire 1 are broken, the electrical connection between the communication devices 101 and 111 through the core wire 1 will be lost.

[0047] [Problem] A technology that can detect partial damage to a target wire with a simple configuration is desired. More specifically, if all of the strands 3 in a core wire 1 are broken and electrical connections between communication devices 101 and 111 are lost, downtime occurs in the communication system 301. From the perspective of predictive maintenance to prevent downtime, a technology that can detect deterioration of the core wire 1 before all of the strands 3 in the core wire 1 are broken is desired.

[0048] The measuring device described in Patent Document 1 is configured to apply a modulated signal to one end of a cable and receive a signal output from the other end of the cable. This configuration requires dedicated lines to connect the measuring device to both ends of the cable, which makes the wiring complicated and may make it difficult to accurately detect cable damage due to the effects of the dedicated lines.

[0049] Therefore, the communication device 101 according to the embodiment of the present disclosure solves the above problem by having the following configuration.

[0050] (Communication Device) FIG. 4 is a diagram illustrating the configuration of a communication device according to an embodiment of the present disclosure. Referring to FIG. 4, the communication device 101 includes a communication unit 11, a detection processing unit 20, and a communication port 30. The detection processing unit 20 includes a signal output unit 12, a measurement unit 13, a processing unit 14, and a storage unit 15. The communication unit 11 is an example of a control unit. The processing unit 14 is an example of a calculation unit and an example of a detection unit. Some or all of the communication unit 11, the signal output unit 12, the measurement unit 13, and the processing unit 14 are implemented, for example, by a processing circuit including one or more processors. The storage unit 15 is, for example, a non-volatile memory included in the processing circuit. The communication port 30 is, for example, a connector or a terminal. A connector portion of the transmission line 10 is connected to the communication port 30.

[0051] The communication device 101 functions as a detection device. For example, the communication device 101 is activated in synchronization with the start of operations of the communication system 301. The detection processing unit 20 in the communication device 101 performs detection processing to detect partial damage to the core wire 1 once a day as a pre-operational inspection. For example, the detection processing unit 20 detects breaks in some of the multiple strands 3 in the core wire 1 as partial damage to the core wire 1. Hereinafter, breaks in some of the multiple strands 3 in the core wire 1 will also be referred to as partial breaks. Note that the detection processing unit 20 may be configured to detect thinning of the strands 3 in the core wire 1 as partial damage to the core wire 1.

[0052] For example, the end of the transmission line 10 on the communication device 111 side is impedance-matched. More specifically, the end of the transmission line 10 on the communication device 111 side is connected to a termination circuit (not shown). The termination circuit is a 50 Ω resistor that is equal to the characteristic impedance of the transmission line 10, and is used to match the termination of the transmission line 10. Note that the termination circuit may be a load other than a 50 Ω resistor, and may not accurately match the termination of the transmission line 10. In other words, the end of the transmission line 10 does not need to be accurately impedance-matched.

[0053] The communication unit 11 generates a communication signal Sc addressed to the communication device 111 periodically or irregularly during a period other than the detection period T1 during which the detection processing unit 20 performs detection processing, and transmits the generated communication signal Sc to the communication device 111 via the communication port 30 and the transmission line 10. The communication unit 11 also receives a response signal Sr in response to the communication signal Sc and sensor information from the communication device 111 via the communication port 30 and the transmission line 10.

[0054] When the communication device 101 is started up, the processing unit 14 outputs a detection instruction indicating a predetermined length of detection period T1 to the communication unit 11, the signal output unit 12, and the measurement unit 13.

[0055] (Control of Attitude in Detection Period T1) The communication unit 11 controls the attitude of the core wire 1 in the detection period T1. For example, a control pattern Pt of the attitude of the core wire 1 by the communication unit 11 can be set. More specifically, the administrator of the communication system 301 determines the control pattern Pt in advance and provides the determined control pattern Pt to the communication device 101.

[0056] The communication unit 11 receives a detection instruction from the processing unit 14 and generates a communication signal Sc1 for controlling the attitude of the transmission line 10 during the detection period T1 in accordance with the control pattern Pt received from the administrator.

[0057] For example, the communication unit 11 generates a communication signal Sc1 for applying a predetermined bending operation to the transmission line 10 during the detection period T1. As an example, the communication unit 11 generates a communication signal Sc1 for applying a bending operation BM that causes the bending angle θxy of the transmission line 10 to go back and forth between +90° and −90° during the detection period T1. The communication unit 11 transmits the generated communication signal Sc1 to the communication device 111 via the transmission line 10.

[0058] The communication device 111 operates the robot arm in accordance with the communication signal Sc1 received from the communication device 101 during the detection period T1, thereby applying a bending motion BM to the transmission line 10.

[0059] (Transmission of Measurement Signal) The signal output unit 12 outputs a measurement signal having frequency components to multiple core wires 1 whose posture changes. For example, the signal output unit 12 outputs an AC signal, a pulse signal, or a frequency sweep signal as the measurement signal to three predetermined core wires 1 in the transmission line 10. As an example, the signal output unit 12 outputs the measurement signal to core wires 1A, 1B, and 1C. The core wires 1A, 1B, and 1C are examples of target wires. Some or all of the core wires 1A, 1B, and 1C may be core wires 1 used to transmit a communication signal Sc from the communication unit 11 to the communication device 111, or may be core wires 1 used to transmit a response signal Sr and sensor information from the communication device 111 to the communication unit 11. Here, the period of the measurement signal is sufficiently smaller than the detection period T1. The signal output unit 12 may be configured to output the measurement signal to one, two, four, or more core wires 1.

[0060] More specifically, upon receiving a detection instruction from the processing unit 14, the signal output unit 12 outputs measurement signals in parallel to the core wires 1A, 1B, and 1C of the transmission line 10 undergoing the bending operation BM during the detection period T1 via the communication port 30. Note that the signal output unit 12 may be configured to output measurement signals in a time-division manner to the core wires 1A, 1B, and 1C of the transmission line 10 undergoing the bending operation BM during the detection period T1 via the communication port 30.

[0061] For example, the storage unit 15 stores a digital signal D1 having N samples obtained by digitally converting one cycle of a sine wave, where N is an integer equal to or greater than 2.

[0062] During the detection period T1, the signal output unit 12 repeatedly uses N digital signals D1 corresponding to one cycle of a sine wave stored in the storage unit 15 to output M cycles of measurement signals to the core wires 1A, 1B, and 1C. M is an integer equal to or greater than 2. More specifically, the signal output unit 12 includes a DA (Digital-to-Analog) converter. The signal output unit 12 acquires the digital signal D1 from the storage unit 15 at an output timing that corresponds to a cycle C1 of an operating clock of the DA converter, and outputs M cycles of measurement signals generated by converting the digital signal D1 to analog using the DA converter to the core wires 1A, 1B, and 1C via the communication port 30. The signal output unit 12 also outputs the digital signal D1 acquired from the storage unit 15 at the output timing to the measurement unit 13 and the processing unit 14.

[0063] The signal output unit 12 may include a signal generating unit such as a DDS (Direct Digital Synthesizer) and output a signal generated by the signal generating unit to the core wires 1A, 1B, and 1C via the communication port 30.

[0064] (Receiving Response Signals) The measuring unit 13 receives response signals, each including a reflected measurement signal, from each of the core wires 1A, 1B, and 1C, and measures the amplitude and phase of each of the received response signals. For example, the measuring unit 13 receives, via the communication port 30, from each of the core wires 1A, 1B, and 1C, a response signal including the measurement signal output by the signal output unit 12 and a reflected signal, which is a signal obtained by reflecting the measurement signal.

[0065] More specifically, upon receiving a detection instruction from the processing unit 14, the measuring unit 13 receives, during the detection period T1, response signals from the core wires 1A, 1B, and 1C via the communication port 30. For example, the measuring unit 13 performs preprocessing to remove noise contained in the response signals using a low-pass filter or the like.

[0066] The measurement unit 13 includes an AD (Analog to Digital) converter that samples the response signal at sampling timings according to the period C1. The measurement unit 13 generates a digital signal D2A, which is time-series data made up of a plurality of sample values, by using the AD converter to sample the response signal received from core wire 1A and subjected to preprocessing. The measurement unit 13 also generates a digital signal D2B, which is time-series data made up of a plurality of sample values, by using the AD converter to sample the response signal received from core wire 1B and subjected to preprocessing. The measurement unit 13 also generates a digital signal D2C, which is time-series data made up of a plurality of sample values, by using the AD converter to sample the response signal received from core wire 1C and subjected to preprocessing.

[0067] For example, when the measurement unit 13 generates the digital signal D2A, it subtracts the digital signal D1 received from the signal output unit 12 for each sample from the generated digital signal D2A to generate a digital signal D3A that is time-series data indicating the reflected signal. Based on the generated digital signal D3A, the measurement unit 13 generates amplitude data D3aA that is time-series data on the amplitude of the reflected signal and phase data D3pA that is time-series data on the phase of the reflected signal, and outputs the generated amplitude data D3aA and phase data D3pA to the processing unit 14.

[0068] Furthermore, for example, when the measurement unit 13 generates the digital signal D2B, it generates a digital signal D3B that is time-series data indicating the reflected signal by subtracting the digital signal D1 received from the signal output unit 12 for each sample from the generated digital signal D2B. The measurement unit 13 generates amplitude data D3aB that is time-series data on the amplitude of the reflected signal and phase data D3pB that is time-series data on the phase of the reflected signal based on the generated digital signal D3A, and outputs the generated amplitude data D3aB and phase data D3pB to the processing unit 14.

[0069] Furthermore, for example, when the measurement unit 13 generates the digital signal D2C, it generates a digital signal D3C that is time-series data indicative of the reflected signal by subtracting the digital signal D1 received from the signal output unit 12 for each sample from the generated digital signal D2C. The measurement unit 13 generates amplitude data D3aC that is time-series data on the amplitude of the reflected signal and phase data D3pC that is time-series data on the phase of the reflected signal based on the generated digital signal D3C, and outputs the generated amplitude data D3aC and phase data D3pC to the processing unit 14.

[0070] Hereinafter, each of the amplitude data D3aA, D3aB, and D3aC will also be referred to as amplitude data D3a, and each of the phase data D3pA, D3pB, and D3pC will also be referred to as phase data D3p.

[0071] (Detection of partial disconnection) Based on the measurement results by the measurement unit 13, the processing unit 14 calculates, for each core wire 1, a plurality of evaluation values ​​Ev corresponding to a plurality of attitudes of the core wire 1. The processing unit 14 detects a partial disconnection of the core wire 1 based on the calculated plurality of evaluation values ​​Ev for each core wire 1.

[0072] (Detection Example 1) The processing unit 14 calculates, as the evaluation value Ev, the absolute value of the reflection coefficient, which is the ratio of the amplitude of the measurement signal to the amplitude of the reflected signal.

[0073] More specifically, processing unit 14 generates amplitude data D1a, which is time-series data of the amplitude of the measurement signal, based on the digital signal D1 received from signal output unit 12. Processing unit 14 calculates value VLA by dividing amplitude data D3aA received from measurement unit 13 by amplitude data D1a, for example, for each period of the measurement signal, i.e., for each N number of samples. Specifically, processing unit 14 calculates value VLA by dividing the average value of N sample values ​​of amplitude data D3aA by the average value of N sample values ​​of amplitude data D1a.

[0074] 5 is a diagram illustrating an example of absolute values ​​of reflection coefficients calculated by a processing unit in a communication device according to an embodiment of the present disclosure. In FIG. 5, the horizontal axis represents time (seconds) and the vertical axis represents absolute values ​​of the reflection coefficients. FIG. 5 shows absolute values ​​abA of M reflection coefficients rcA during a detection period T1.

[0075] Referring to FIG. 5, the processing unit 14 calculates absolute values ​​abA of M reflection coefficients rcA in the detection period T1 based on M values ​​VLA calculated for each period of the measurement signal.

[0076] Similarly, the processing unit 14 calculates a value VLB by dividing the amplitude data D3aB received from the measurement unit 13 by the amplitude data D1a, for example, for each period of the measurement signal, i.e., for each N number of samples. The processing unit 14 calculates absolute values ​​abB of the M number of reflection coefficients rcB based on the M values ​​VLB calculated for each period of the measurement signal.

[0077] Similarly, the processing unit 14 calculates a value VLC by dividing the amplitude data D3aC received from the measurement unit 13 by the amplitude data D1a, for example, for each period of the measurement signal, i.e., for each N number of samples. The processing unit 14 calculates absolute values ​​abC of the M number of reflection coefficients rcC based on the M values ​​VLC calculated for each period of the measurement signal.

[0078] Then, the processing unit 14 calculates an average value av1A, which is the average value av1 of the M absolute values ​​abA, an average value av1B, which is the average value av1 of the M absolute values ​​abB, and an average value av1C, which is the average value av1 of the M absolute values ​​abC. Hereinafter, each of the reflection coefficients rcA, rcB, and rcC will also be referred to as a reflection coefficient rc, and each of the absolute values ​​abA, abB, and abC will also be referred to as an absolute value ab. The average value av1 is an example of a statistical value.

[0079] Fig. 6 is a diagram showing an example of a change over time in the average value of the absolute values ​​of the reflection coefficients of a core wire. In Fig. 6, the horizontal axis represents the date, and the vertical axis represents the average value of the absolute values ​​of the reflection coefficients. Fig. 6 shows the average value av1X, which is the average value av1 for the core wire 1X, which is the core wire 1, when a bending test is performed on the transmission line 10 by applying a predetermined number of bending operations BM once a day, and the average value av1 is detected once a day. The detection date t0 in Fig. 6 is the first detection date after the start of the bending test. The detection date td in Fig. 6 is the detection date immediately after all of the strands 3 in the core wire 1X are broken.

[0080] Referring to FIG. 6, the average value av1X increases suddenly on the detection date td due to breakage of all the wires 3 in the core wire 1X.

[0081] Fig. 7 is a diagram showing an example of the change over time in the average absolute value of the reflection coefficient of the core wire. In Fig. 7, the horizontal axis represents the date, and the vertical axis represents the average absolute value of the reflection coefficient. Fig. 7 is an enlarged view in the vertical axis direction of the period from detection date t0 to detection date td in Fig. 6.

[0082] Referring to FIG. 7, the average value av1X gradually increases as some of the wires 3 break during a period before the timing at which all of the wires 3 in the core wire 1X break.

[0083] Based on the average value av1, the processing unit 14 detects a partial disconnection of the core wire 1. For example, the processing unit 14 detects a partial disconnection of the core wire 1 based on a result of comparing the average value av1 with a predetermined threshold value Th1.

[0084] More specifically, after calculating the average value av1A, the processing unit 14 compares the calculated average value av1A with a threshold value Th1. If the average value av1A is less than the threshold value Th1, the processing unit 14 determines that the core wire 1A is not partially broken. On the other hand, if the average value av1A is equal to or greater than the threshold value Th1, the processing unit 14 determines that the core wire 1A is partially broken.

[0085] Furthermore, after calculating the average value av1B, the processing unit 14 compares the calculated average value av1B with a threshold value Th1. If the average value av1B is less than the threshold value Th1, the processing unit 14 determines that the core wire 1B is not partially broken. On the other hand, if the average value av1B is equal to or greater than the threshold value Th1, the processing unit 14 determines that the core wire 1B is partially broken.

[0086] Furthermore, after calculating the average value av1C, the processing unit 14 compares the calculated average value av1C with a threshold value Th1. If the average value av1C is less than the threshold value Th1, the processing unit 14 determines that the core wire 1C is not partially broken. On the other hand, if the average value av1C is equal to or greater than the threshold value Th1, the processing unit 14 determines that the core wire 1C is partially broken.

[0087] The processing unit 14 further detects the degree of progression of damage to the core wire 1. For example, the processing unit 14 detects a proportion R1 of broken wires 3 among the multiple wires 3 in the core wire 1 as the degree of progression of damage to the core wire 1. More specifically, when the average value av1 is equal to or greater than the threshold value Th1, the processing unit 14 calculates a difference dth between the average value av1 and the threshold value Th1. For example, the storage unit 15 stores a correspondence table Tb indicating the correspondence relationship between the difference dth and the proportion R1. The processing unit 14 obtains the proportion R1 corresponding to the calculated difference dth from the correspondence table Tb1 in the storage unit 15.

[0088] The processing unit 14 stores the detection result of the partial disconnection of the core wire 1 in the storage unit 15. The processing unit 14 also performs a notification process of notifying the administrator of the communication system 301 of the detection result.

[0089] The processing unit 14 may be configured to detect a partial disconnection of the core wire 1 based on a change in the average value av1 over time, instead of the result of comparing the average value av1 with the threshold value Th1.

[0090] More specifically, after calculating the average value av1A, the processing unit 14 calculates the amount of change in the average value av1A per unit time based on the average value av1A during the past detection period T1. If the calculated amount of change is less than a predetermined value, the processing unit 14 determines that the core wire 1A does not have a partial break. On the other hand, if the calculated amount of change is equal to or greater than a predetermined value, the processing unit 14 determines that the core wire 1A has a partial break. The processing unit 14 similarly determines whether or not the core wires 1B and 1C have a partial break based on the amount of change in the average values ​​av1B and av1C per unit time.

[0091] (Detection Example 2) The processing unit 14 calculates the absolute value ab of the reflection coefficient rc as the evaluation value Ev, similarly to Detection Example 1. The processing unit 14 detects a partial disconnection of the core wire 1 based on the relationship between the multiple absolute values ​​ab for each core wire 1.

[0092] Fig. 8 is a diagram showing an example of a change over time in the average value of the absolute values ​​of the reflection coefficients of core wires. In Fig. 8, the horizontal axis represents the date, and the vertical axis represents the average value of the absolute values ​​of the reflection coefficients. Fig. 8 shows average values ​​av1Y and av1Z, which are the average values ​​av1 for core wires 1Y and 1Z that are different from the broken core wire 1X, when a bending test is performed on the transmission line 10 in which the transmission line 10 is subjected to a predetermined number of bending operations BM once a day and the average value av1 is detected once a day.

[0093] 8 , the average values ​​av1Y and av1Z of the absolute values ​​of the reflection coefficients of the core wires 1Y and 1Z fluctuate on the detection date td due to the influence of a break in the strands 3 in the core wire 1X. Therefore, in a configuration in which a partial break in a core wire 1 is detected based on the average value av1 of the absolute values ​​ab of the core wire 1, the influence that the break in one core wire 1 has on the electrical characteristics of the other core wires 1 may result in erroneous detection of a partial break.

[0094] Therefore, the processing unit 14 calculates the average value av1 for each core wire 1, and identifies the core wire 1 that is partially broken among the core wires 1A, 1B, and 1C based on the comparison result of each average value av1.

[0095] More specifically, the processing unit 14 calculates the average values ​​av1A, av1B, and av1C in the same manner as in Detection Example 1. Furthermore, the processing unit 14 calculates the difference between the average values ​​av1 in each combination of the average values ​​av1 for all combinations of the average values ​​av1. That is, the processing unit 14 calculates an absolute value V1ab, which is the absolute value V1 of the difference between the average values ​​av1A and av1B, an absolute value V1bc, which is the absolute value V1 of the difference between the average values ​​av1B and av1C, and an absolute value V1ca, which is the absolute value V1 of the difference between the average values ​​av1C and av1A.

[0096] The processing unit 14 compares the absolute value V1 with a predetermined threshold value Th2. If all of the calculated absolute values ​​V1 are less than the threshold value Th2, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken.

[0097] On the other hand, if all the absolute values ​​V1 calculated using the average value av1A are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1A is partially broken. That is, if both of the absolute values ​​V1ab and V1ca are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1A is partially broken.

[0098] On the other hand, if all the absolute values ​​V1 calculated using the average value av1B are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1B is partially broken. That is, if both of the absolute values ​​V1ab and V1bc are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1B is partially broken.

[0099] On the other hand, if all the absolute values ​​V1 calculated using the average value av1C are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1C is partially broken. That is, if both of the absolute values ​​V1bc and V1ca are equal to or greater than the threshold value Th2, the processing unit 14 determines that the core wire 1C is partially broken.

[0100] (Detection Example 3) The processing unit 14 calculates the absolute values ​​abA, abB, and abC in the same manner as in Detection Example 1. Then, the processing unit 14 calculates a variance va1A that is the variance va1 of the M absolute values ​​abA, a variance va1B that is the variance va1 of the M absolute values ​​abB, and a variance va1C that is the variance va1 of the M absolute values ​​abC. The variance va1 is an example of a statistical value.

[0101] Fig. 9 is a diagram showing an example of the change over time in the dispersion of the absolute value of the reflection coefficient of a core wire. In Fig. 9, the horizontal axis represents the date, and the vertical axis represents the dispersion of the absolute value of the reflection coefficient. Fig. 9 shows dispersion va1X, which is the dispersion va1 of core wire 1X, when a bending test is performed on transmission line 10, in which the transmission line 10 is subjected to a predetermined number of bending operations BM once a day, and the dispersion va1 is detected once a day.

[0102] Referring to FIG. 9, the variance va1X increases suddenly on the detection date td due to the breakage of all the strands 3 in the core wire 1X.

[0103] Fig. 10 is a diagram showing an example of the change over time in the variance of the absolute value of the reflection coefficient of the core wire. In Fig. 10, the horizontal axis represents the date, and the vertical axis represents the variance of the absolute value of the reflection coefficient. Fig. 10 is an enlarged view in the vertical axis direction of the period from detection date t0 to detection date td in Fig. 9.

[0104] Referring to FIG. 10, the variance va1X gradually increases as some of the wires 3 break during a period before the timing at which all of the wires 3 in the core wire 1X break.

[0105] Based on the variance va1, the processing unit 14 detects a partial disconnection of the core wire 1. For example, the processing unit 14 detects a partial disconnection of the core wire 1 based on a result of comparing the variance va1 with a predetermined threshold value Th3.

[0106] More specifically, after calculating the variance va1A, the processing unit 14 compares the calculated variance va1A with a threshold value Th3. If the variance va1A is less than the threshold value Th3, the processing unit 14 determines that the core wire 1A is not partially broken. On the other hand, if the variance va1A is equal to or greater than the threshold value Th3, the processing unit 14 determines that the core wire 1A is partially broken.

[0107] Furthermore, after calculating the variance va1B, the processing unit 14 compares the calculated variance va1B with a threshold value Th3. If the variance va1B is less than the threshold value Th3, the processing unit 14 determines that the core wire 1B is not partially broken. On the other hand, if the variance va1B is equal to or greater than the threshold value Th3, the processing unit 14 determines that the core wire 1B is partially broken.

[0108] Furthermore, after calculating the variance va1C, the processing unit 14 compares the calculated variance va1C with a threshold value Th3. If the variance va1C is less than the threshold value Th3, the processing unit 14 determines that the core wire 1C is not partially broken. On the other hand, if the variance va1C is equal to or greater than the threshold value Th3, the processing unit 14 determines that the core wire 1C is partially broken.

[0109] The processing unit 14 may be configured to detect a partial disconnection of the core wire 1 based on a change in the variance va1 over time, instead of the result of comparing the variance va1 with the threshold value Th3.

[0110] More specifically, after calculating the variance va1A, the processing unit 14 calculates the amount of change in variance va1A per unit time based on the variance va1A during the past detection period T1. If the calculated amount of change is less than a predetermined value, the processing unit 14 determines that core wire 1A is not partially broken. On the other hand, if the calculated amount of change is equal to or greater than a predetermined value, the processing unit 14 determines that core wire 1A is partially broken. The processing unit 14 similarly determines whether core wires 1B and 1C are partially broken based on the amount of change in variances va1B and va1C per unit time.

[0111] (Detection Example 4) The processing unit 14 detects a partial break in a core wire 1 based on the relationship between the multiple absolute values ​​ab for each core wire 1. More specifically, the processing unit 14 calculates a variance va1 of the M absolute values ​​ab for each core wire 1, and identifies a core wire 1 that is partially broken among the core wires 1A, 1B, and 1C based on a comparison result of each variance va1.

[0112] More specifically, the processing unit 14 calculates the variances va1A, va1B, and va1C in the same manner as in Detection Example 3. Furthermore, the processing unit 14 calculates the difference between the variances va1 and va1 in each combination of variances va1. That is, the processing unit 14 calculates an absolute value V2ab, which is the absolute value V2 of the difference between variances va1A and va1B, an absolute value V2bc, which is the absolute value V2 of the difference between variances va1B and va1C, and an absolute value V2ca, which is the absolute value V2 of the difference between variances va1C and va1A.

[0113] The processing unit 14 compares the absolute value V2 with a predetermined threshold value Th4. If all of the calculated absolute values ​​V2 are less than the threshold value Th4, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken.

[0114] On the other hand, if all the absolute values ​​V2 calculated using the variance va1A are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1A is partially broken. That is, if both the absolute values ​​V2ab and V2ca are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1A is partially broken.

[0115] Furthermore, if all the absolute values ​​V2 calculated using the variance va1B are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1B is partially broken. That is, if both the absolute values ​​V2ab and V2bc are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1B is partially broken.

[0116] Furthermore, if all the absolute values ​​V2 calculated using the variance va1C are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1C is partially broken. That is, if both the absolute values ​​V2bc and V2ca are equal to or greater than the threshold value Th4, the processing unit 14 determines that the core wire 1C is partially broken.

[0117] (Detection Example 5) The processing unit 14 calculates the phase difference between the reflected signal and the measurement signal as the evaluation value E. More specifically, the processing unit 14 generates phase data D1p, which is time-series data of the phase of the measurement signal, based on the digital signal D1 received from the signal output unit 12.

[0118] The processing unit 14 calculates the difference PLA between the phase data D3pA and D1p received from the measurement unit 13, for example, for each period of the measurement signal, i.e., for each N samples. Specifically, the processing unit 14 calculates the difference PLA between the average value of the N sample values ​​of the phase data D3pA and the average value of the N sample values ​​of the phase data D1p. The processing unit 14 calculates M phase differences pdA during the detection period T1 based on the M differences PLA calculated for each period of the measurement signal.

[0119] Similarly, the processing unit 14 calculates a difference PLB between the phase data D3pB and the phase data D1p received from the measurement unit 13, for example, for each period of the measurement signal, i.e., for each N number of samples. The processing unit 14 calculates M phase differences pdB based on the M differences PLB calculated for each period of the measurement signal.

[0120] Similarly, the processing unit 14 calculates the difference PLC between the phase data D3pC and D1p received from the measurement unit 13, for example, for each period of the measurement signal, i.e., for each N number of samples. The processing unit 14 calculates M number of phase differences pdC based on the M number of differences PLC calculated for each period of the measurement signal.

[0121] The processing unit 14 then calculates an average value av2A, which is the average value av2 of the M phase differences pdA, an average value av2B, which is the average value av2 of the M phase differences pdB, and an average value av2C, which is the average value av2 of the M phase differences pdC. Hereinafter, each of the phase differences pdA, pdB, and pdC will also be referred to as a phase difference pd. The average value av2 is an example of a statistical value.

[0122] Fig. 11 is a diagram showing an example of a change over time in the average value of the phase difference between the reflected signal and the measurement signal in the core wire. In Fig. 11, the horizontal axis represents the date, and the vertical axis represents the average value of the phase difference [degree]. Fig. 11 shows the average value av2X, which is the average value av2 for the core wire 1X, when a bending test is performed in which the transmission line 10 is subjected to a predetermined number of bending operations BM once a day, and the average value av2 is detected once a day.

[0123] 11 , the average value av2X increases sharply on the detection date td when all of the wires 3 in the core wire 1X are broken. Note that the average value av2X may increase or decrease when all of the wires 3 in the core wire 1X are broken, depending on the position of the break in the longitudinal direction of the core wire 1X and the length of the core wire 1X.

[0124] Fig. 12 is a diagram showing an example of a change over time in the average value of the phase difference between the reflected signal and the measurement signal in the core wire. In Fig. 12, the horizontal axis represents the date, and the vertical axis represents the average value of the phase difference [degree]. Fig. 12 is an enlarged view in the vertical axis direction of the period from detection date t0 to detection date td in Fig. 11.

[0125] 12 , the average value av2X gradually increases as some of the wires 3 break during a period before all of the wires 3 in the core wire 1X break. Note that when the average value av2X decreases as all of the wires 3 in the core wire 1X break, the average value av2X also gradually decreases as some of the wires 3 break.

[0126] Based on the change over time in the average value av2, the processing unit 14 detects a partial disconnection of the core wire 1. For example, based on the result of comparing the absolute value of the amount of change in the average value av2 with a predetermined threshold value Th5, the processing unit 14 detects a partial disconnection of the core wire 1.

[0127] More specifically, after calculating the average value av2A, the processing unit 14 calculates an absolute value vr2A, which is the absolute value vr2 of the amount of change in the average value av2A per unit time, based on the average value av2A over the past detection period T1. The processing unit 14 compares the calculated absolute value vr2A with a threshold value Th5. If the absolute value vr2A is less than the threshold value Th5, the processing unit 14 determines that the core wire 1A is not partially broken. On the other hand, if the absolute value vr2A is equal to or greater than the threshold value Th5, the processing unit 14 determines that the core wire 1A is partially broken.

[0128] After calculating the average value av2B, the processing unit 14 calculates an absolute value vr2B, which is the absolute value vr2 of the amount of change in the average value av2B per unit time, based on the average value av2B during the past detection period T1. The processing unit 14 compares the calculated absolute value vr2B with a threshold value Th5. If the absolute value vr2B is less than the threshold value Th5, the processing unit 14 determines that the core wire 1B is not partially broken. On the other hand, if the absolute value vr2B is equal to or greater than the threshold value Th5, the processing unit 14 determines that the core wire 1B is partially broken.

[0129] After calculating the average value av2C, the processing unit 14 calculates an absolute value vr2C, which is the absolute value vr2 of the amount of change in the average value av2C per unit time, based on the average value av2C in the past detection period T1. The processing unit 14 compares the calculated absolute value vr2C with a threshold value Th5. If the absolute value vr2C is less than the threshold value Th5, the processing unit 14 determines that the core wire 1C is not partially broken. On the other hand, if the absolute value vr2C is equal to or greater than the threshold value Th5, the processing unit 14 determines that the core wire 1C is partially broken.

[0130] (Detection Example 6) The processing unit 14 detects a partial break in a core wire 1 based on the relationship between the multiple phase differences pd for each core wire 1. More specifically, the processing unit 14 calculates the absolute value vr2 for each core wire 1, and identifies the core wire 1 that is partially broken among the core wires 1A, 1B, and 1C based on a comparison result of each absolute value vr2.

[0131] More specifically, the processing unit 14 calculates the absolute values ​​vr2A, vr2B, and vr2C in the same manner as in Detection Example 5. Furthermore, for all combinations of the absolute values ​​vr2, the processing unit 14 calculates the difference between the absolute values ​​vr2 in each combination. That is, the processing unit 14 calculates an absolute value V3ab, which is the absolute value V3 of the difference between the absolute values ​​vr2A and vr2B, an absolute value V3bc, which is the absolute value V3 of the difference between the absolute values ​​vr2B and vr2C, and an absolute value V3ca, which is the absolute value V3 of the difference between the absolute values ​​vr2C and vr2A.

[0132] The processing unit 14 compares the absolute value V3 with a predetermined threshold value Th6. If all of the calculated absolute values ​​V3 are less than the threshold value Th6, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken.

[0133] On the other hand, if all the absolute values ​​V3 calculated using the absolute value vr2A are equal to or greater than the threshold value Th6, the processing unit 14 determines that the core wire 1A is partially broken. That is, if both the absolute values ​​V3ab and V3ca are equal to or greater than the threshold value Th6, the processing unit 14 determines that the core wire 1A is partially broken.

[0134] Furthermore, if all absolute values ​​V3 calculated using absolute value vr2B are equal to or greater than threshold value Th6, the processing unit 14 determines that the core wire 1B is partially broken. That is, if both absolute values ​​V3ab and V3bc are equal to or greater than threshold value Th6, the processing unit 14 determines that the core wire 1B is partially broken.

[0135] Furthermore, if all absolute values ​​V3 calculated using absolute value vr2C are equal to or greater than threshold value Th6, the processing unit 14 determines that the core wire 1C is partially broken. That is, if both absolute values ​​V3bc and V3ca are equal to or greater than threshold value Th6, the processing unit 14 determines that the core wire 1C is partially broken.

[0136] (Detection Example 7) The processing unit 14 calculates the phase differences pdA, pdB, and pdC in the same manner as in Detection Example 5. Then, the processing unit 14 calculates a variance va2A that is the variance va2 of the M phase differences pdA, a variance va2B that is the variance va2 of the M phase differences pdB, and a variance va2C that is the variance va2 of the M phase differences pdC. The variance va2 is an example of a statistical value.

[0137] Fig. 13 is a diagram showing an example of a change over time in the dispersion of the phase difference between a reflected signal and a measurement signal in a core wire. In Fig. 13, the horizontal axis represents the date, and the vertical axis represents the dispersion of the phase difference. Fig. 13 shows dispersion va2X, which is the dispersion va2 for core wire 1X, when a bending test is performed in which transmission line 10 is subjected to a predetermined number of bending operations BM once a day, and dispersion va2 is detected once a day.

[0138] Referring to FIG. 13, the variance va2X increases suddenly on the detection date td due to the breakage of all the strands 3 in the core wire 1X.

[0139] Fig. 14 is a diagram showing an example of a change over time in the variance of the phase difference between the reflected signal and the measurement signal in the core wire. In Fig. 14, the horizontal axis represents the date, and the vertical axis represents the variance of the phase difference. Fig. 14 is an enlarged view in the vertical axis direction of the period from detection date t0 to detection date td in Fig. 13.

[0140] Referring to FIG. 14, the variance va2X gradually increases as some of the wires 3 break during a period before the timing at which all of the wires 3 in the core wire 1X break.

[0141] Based on the variance va2, the processing unit 14 detects a partial disconnection of the core wire 1. For example, the processing unit 14 detects a partial disconnection of the core wire 1 based on a result of comparing the variance va2 with a predetermined threshold value Th7.

[0142] More specifically, after calculating the variance va2A, the processing unit 14 compares the calculated variance va2A with a threshold value Th7. If the variance va2A is less than the threshold value Th7, the processing unit 14 determines that the core wire 1A is not partially broken. On the other hand, if the variance va2A is equal to or greater than the threshold value Th7, the processing unit 14 determines that the core wire 1A is partially broken.

[0143] Furthermore, after calculating the variance va2B, the processing unit 14 compares the calculated variance va2B with a threshold value Th7. If the variance va2B is less than the threshold value Th7, the processing unit 14 determines that the core wire 1B is not partially broken. On the other hand, if the variance va2B is equal to or greater than the threshold value Th7, the processing unit 14 determines that the core wire 1B is partially broken.

[0144] Furthermore, after calculating the variance va2C, the processing unit 14 compares the calculated variance va2C with a threshold value Th7. If the variance va2C is less than the threshold value Th7, the processing unit 14 determines that the core wire 1C is not partially broken. On the other hand, if the variance va2C is equal to or greater than the threshold value Th7, the processing unit 14 determines that the core wire 1C is partially broken.

[0145] The processing unit 14 may be configured to detect a partial disconnection of the core wire 1 based on a change in the variance va2 over time, instead of the result of comparing the variance va2 with the threshold value Th7.

[0146] More specifically, after calculating the variance va2A, the processing unit 14 calculates the amount of change in variance va2A per unit time based on the variance va2A during the past detection period T1. If the calculated amount of change is less than a predetermined value, the processing unit 14 determines that core wire 1A is not partially broken. On the other hand, if the calculated amount of change is equal to or greater than a predetermined value, the processing unit 14 determines that core wire 1A is partially broken. The processing unit 14 similarly determines whether core wires 1B and 1C are partially broken based on the amount of change in variances va2B and va2C per unit time.

[0147] (Detection Example 8) The processing unit 14 detects a partial break in a core wire 1 based on the relationship between the multiple phase differences pd for each core wire 1. More specifically, the processing unit 14 calculates the variance va2 of the M phase differences pd for each core wire 1, and identifies the core wire 1 that is partially broken among the core wires 1A, 1B, and 1C based on the comparison result of each variance va2.

[0148] More specifically, the processing unit 14 calculates the variances va2A, va2B, and va2C in the same manner as in Detection Example 7. Furthermore, the processing unit 14 calculates the difference between the variances va2 and va2 in each combination of variances va2. That is, the processing unit 14 calculates an absolute value V4ab, which is the absolute value V4 of the difference between the variances va2A and va2B, an absolute value V4bc, which is the absolute value V4 of the difference between the variances va2B and va2C, and an absolute value V4ca, which is the absolute value V4 of the difference between the variances va2C and va2A.

[0149] The processing unit 14 compares the absolute value V4 with a predetermined threshold value Th8. If all of the calculated absolute values ​​V4 are less than the threshold value Th8, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken.

[0150] On the other hand, if all the absolute values ​​V4 calculated using the variance va2A are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1A is partially broken. That is, if both the absolute values ​​V4ab and V4ca are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1A is partially broken.

[0151] Furthermore, if all absolute values ​​V4 calculated using the variance va2B are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1B is partially broken. That is, if both absolute values ​​V4ab and V4bc are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1B is partially broken.

[0152] Furthermore, if all the absolute values ​​V4 calculated using the variance va2C are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1C is partially broken. That is, if both the absolute values ​​V4bc and V4ca are equal to or greater than the threshold value Th8, the processing unit 14 determines that the core wire 1C is partially broken.

[0153] (Detection Example 9) The processing unit 14 calculates the impedances ZA, ZB, and ZC, which are the impedances Z of the core wires 1A, 1B, and 1C, respectively, as the evaluation value Ev. The processing unit 14 detects a partial disconnection of the core wire 1 based on the relationship between the multiple impedances Z for each core wire 1.

[0154] For example, the processing unit 14 calculates a feature amount Fv indicating a relationship between the impedances Z for each core wire 1 based on the M impedances Z for each core wire 1. As an example, the processing unit 14 calculates, as the feature amount Fv, a regression residual Re of the multiple impedances Z for each core wire 1. The processing unit 14 detects a partial disconnection of the core wire 1 based on the calculated regression residual Re.

[0155] More specifically, the processing unit 14 calculates a value VLA by dividing the average value of N sample values ​​of the amplitude data D3aA by the average value of N sample values ​​of the amplitude data D1a, as in Detection Example 1, and calculates M reflection coefficients rcA for the detection period T1 based on this value VLA. Then, the processing unit 14 calculates M impedances ZA for the detection period T1 according to the following equation (1):

[0156] Here, Zout is the output impedance of the communication device 101. For example, the output impedance Zout is stored in the storage unit 15 in advance.

[0157] Furthermore, similarly to detection example 1, the processing unit 14 calculates a value VLB by dividing the average value of N sample values ​​of the amplitude data D3aB by the average value of N sample values ​​of the amplitude data D1a, and calculates M reflection coefficients rcB for the detection period T1 based on this value VLB. Then, the processing unit 14 calculates M impedances ZB for the detection period T1 according to the following equation (2).

[0158] Furthermore, similarly to Detection Example 1, the processing unit 14 calculates a value VLC by dividing the average value of N sample values ​​of the amplitude data D3aC by the average value of N sample values ​​of the amplitude data D1a, and calculates M reflection coefficients rcC for the detection period T1 based on this value VLC. Then, the processing unit 14 calculates M impedances ZC for the detection period T1 according to the following equation (3).

[0159] Then, the processing unit 14 calculates an average impedance Zave, which is the average value of the M impedances Z in the detection period T1. More specifically, the processing unit 14 calculates, as the average impedance Zave, an average impedance ZaveA, which is the average value of the M impedances ZA in the detection period T1, an average impedance ZaveB, which is the average value of the M impedances ZB in the detection period T1, and an average impedance ZaveC, which is the average value of the M impedances ZC in the detection period T1.

[0160] For example, the storage unit 15 stores regression lines L1AB, L1BC, and L1CA, which are the regression equation L1. The regression line L1AB is generated by linear regression analysis of the impedances ZA and ZB of the undamaged core wires 1A and 1B before the start of operation of the communication system 301. The regression line L1BC is generated by linear regression analysis of the impedances ZB and ZC of the undamaged core wires 1B and 1C before the start of operation of the communication system 301. The regression line L1CA is generated by linear regression analysis of the impedances ZC and ZA of the undamaged core wires 1C and 1A before the start of operation of the communication system 301. Note that the regression lines L1AB, L1BC, and L1CA may also be generated by linear regression analysis of the impedances of multiple core wires 1 in a transmission line 10A that is a test transmission line 10, which is different from the transmission line 10 in the communication system 301.

[0161] After calculating the average impedances ZaveA, ZaveB, and ZaveC, the processing unit 14 calculates a regression residual Re based on the calculated average impedances ZaveA, ZaveB, and ZaveC and the regression lines L1AB, L1BC, and L1CA. More specifically, the processing unit 14 calculates, as the regression residual Re, a regression residual ReAB that is the difference between the average impedances ZaveA and ZaveB and the regression line L1AB, a regression residual ReBC that is the difference between the average impedances ZaveB and ZaveC and the regression line L1BC, and a regression residual ReCA that is the difference between the average impedances ZaveC and ZaveA and the regression line L1CA.

[0162] Fig. 15 is a diagram showing an example of a scatter diagram of the impedances of two core wires in a test transmission line. In Fig. 15, the horizontal axis represents impedance ZA, and the vertical axis represents impedance ZB. Fig. 15 shows a scatter diagram of impedances ZA and ZB obtained by measuring the impedances ZA and ZB of the core wires 1A and 1B in the transmission line 10A multiple times at a predetermined cycle while repeatedly applying bending motions BM to the test transmission line 10A during a test period Tt1. It is assumed that no damage occurred to the core wires 1A and 1B in the transmission line 10A during the test period Tt1. The dashed line in Fig. 15 represents a regression line Lr1 obtained by linear regression analysis of the impedances ZA and ZB.

[0163] FIG. 16 is a diagram showing an example of a scatter diagram of the impedances of two core wires in a test transmission line. In FIG. 16, the horizontal axis represents impedance ZC, and the vertical axis represents impedance ZD. FIG. 16 shows a scatter diagram of impedances ZC and ZD obtained by measuring the impedances ZC and ZD of core wires 1C and 1D in transmission line 10A multiple times at predetermined intervals while repeatedly applying bending motions BM to transmission line 10A during test period Tt1. During test period Tt1, core wire 1C in transmission line 10A was not damaged, while core wire 1D in transmission line 10A was partially broken. The dashed line in FIG. 16 represents a regression line Lr2 obtained by linear regression analysis of the impedances ZC and ZD of core wire 1D before damage occurred.

[0164] 17 and 18 are diagrams showing an example of changes over time in the regression residuals of the impedances of two core wires in a test transmission line. In FIGS. 17 and 18, the horizontal axis represents time, and the vertical axis represents the regression residuals. FIG. 17 shows changes over time in the regression residual Re1, which is the difference between the regression line Lr1 and the impedances ZC and ZD, during the test period Tt1. FIG. 18 shows changes over time in the regression residual Re2, which is the difference between the regression line Lr2 and the impedances ZC and ZD, during the test period Tt1.

[0165] 15 to 18, the impedances ZA and ZB of the core wires 1A and 1B are more highly correlated than the impedances ZC and ZD of the core wires 1C and 1D. The regression residual Re1 is stably low compared to the regression residual Re2. This is because the changes in the impedances ZA and ZB due to the influence of changes in the environment of the transmission line 10A and changes in the posture of the transmission line 10A are highly correlated.

[0166] On the other hand, the impedances ZC and ZD of the core wires 1C and 1D have a lower correlation than the impedances ZA and ZB of the core wires 1A and 1B. The regression residual Re2 gradually increases during the test period Tt1. This is because the partial disconnection of the core wire 1D causes only the impedance ZD of the impedances ZC and ZD to change.

[0167] After calculating the regression residual Re, the processing unit 14 compares the calculated regression residual Re with a predetermined threshold Th9. The threshold Th9 may be set based on the calculation results of the impedances ZA, ZB, and ZC of the core wires 1A, 1B, and 1C before the start of operation of the communication system 301, or may be set based on the measurement results of the impedances of the multiple core wires 1 in the test transmission line 10A.

[0168] If all the calculated regression residuals Re are less than the threshold value Th9, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken.

[0169] On the other hand, if at least one of the regression residuals Re is equal to or greater than the threshold value Th9, the processing unit 14 determines that at least one of the core wires 1A, 1B, and 1C is partially broken.

[0170] More specifically, when the regression residual Re is equal to or greater than the threshold value Th9, the processing unit 14 determines that at least one of the core wires 1A, 1B, and 1C has a partial break. In this case, the processing unit 14 identifies the core wire 1 that has a partial break based on the comparison result between the multiple regression residuals Re and the threshold value Th9.

[0171] Specifically, the processing unit 14 determines that the core wire 1A is partially broken when all the regression residuals Re calculated using the impedance ZA are equal to or greater than the threshold value Th9. That is, the processing unit 14 determines that the core wire 1A is partially broken when both of the regression residuals ReAB and ReCA are equal to or greater than the threshold value Th9.

[0172] On the other hand, when all the regression residuals Re calculated using the impedance ZB are equal to or greater than the threshold value Th9, the processing unit 14 determines that the core wire 1B is partially open. That is, when both of the regression residuals ReAB and ReBC are equal to or greater than the threshold value Th9, the processing unit 14 determines that the core wire 1B is partially open.

[0173] On the other hand, when all the regression residuals Re calculated using the impedance ZC are equal to or greater than the threshold value Th9, the processing unit 14 determines that the core wire 1C is partially open. That is, when both of the regression residuals ReBC and ReCA are equal to or greater than the threshold value Th9, the processing unit 14 determines that the core wire 1C is partially open.

[0174] The processing unit 14 may calculate the regression residual Re based on the average impedance Zave of three or more core wires 1 and the regression equation L1 generated by performing regression analysis on the impedances Z of the three or more core wires 1. More specifically, the processing unit 14 calculates the regression residual Re, which is the difference between the average impedance Zave of K core wires 1 and the regression equation L1 generated by performing regression analysis on the impedances Z of the K core wires 1, where K is an integer equal to or greater than 3. The processing unit 14 detects a partial disconnection of a core wire 1 based on the result of comparing the calculated regression residual Re with a predetermined threshold.

[0175] (Detection Example 10) The processing unit 14 calculates the impedances ZA, ZB, and ZC, which are the impedances Z of the core wires 1A, 1B, and 1C, respectively, as the evaluation value Ev. The processing unit 14 detects a partial disconnection of the core wire 1 based on the relationship between the multiple impedances Z for each core wire 1.

[0176] For example, the processing unit 14 calculates a feature quantity Fv indicating the relationship between the impedances Z for each core wire 1, based on the M impedances Z for each core wire 1. As an example, the processing unit 14 calculates feature quantities PC1 and PC2 as the feature quantity Fv by dimensionally compressing the multiple impedances Z for each core wire 1. The processing unit 14 detects a partial disconnection of the core wire 1 based on the calculated feature quantities PC1 and PC2.

[0177] More specifically, the processing unit 14 calculates the impedances ZA, ZB, and ZC and the average impedances ZaveA, ZaveB, and ZaveC in the same manner as in Detection Example 9. The processing unit 14 calculates feature quantities PC1 and PC2 of the average impedances ZaveA, ZaveB, and ZaveC by dimensionally compressing the calculated average impedances ZaveA, ZaveB, and ZaveC according to a principal component analysis (PCA) technique. For example, the processing unit 14 obtains, as feature quantities PC1 and PC2, coordinates on two mutually perpendicular axes in a plane perpendicular to the principal component axes of the average impedances ZaveA, ZaveB, and ZaveC according to the principal component analysis technique.

[0178] Note that the processing unit 14 may calculate the feature quantities PC1 and PC2 of the average impedances ZaveA, ZaveB, and ZaveC using other methods such as independent component analysis (ICA), non-negative matrix factorization (NMF), and partial least squares regression (PLS) instead of principal component analysis.

[0179] 19 and 20 are diagrams showing examples of scatter plots of feature quantities of the impedance of core wires in a test transmission line. In FIGS. 19 and 20, the horizontal axis represents feature quantity PC1, and the vertical axis represents feature quantity PC2. FIG. 19 shows a scatter plot of feature quantities PC1 and PC2 of impedance ZA, ZB, ZC, and ZD obtained when the impedances ZA, ZB, ZC, and ZD of core wires 1A, 1B, 1C, and 1D of transmission line 10A are detected multiple times at a predetermined cycle while repeatedly applying bending motions BM to transmission line 10A during test period Tt2. FIG. 20 shows a scatter plot of feature quantities PC1 and PC2 of impedance ZA, ZB, ZC, and ZD obtained when the impedances ZA, ZB, ZC, and ZD of core wires 1A, 1B, 1C, and 1D of transmission line 10A are detected multiple times at a predetermined cycle while repeatedly applying bending motions BM to transmission line 10A during test period Tt3. During test period Tt2, core wires 1A, 1B, 1C, and 1D were not damaged, while during test period Tt3, core wire 1A of core wires 1A, 1B, 1C, and 1D was partially broken. The dashed lines in Figures 19 and 20 indicate the numerical range Rg, which is the threshold value used in the detection process.

[0180] 19 and 20 , the feature quantities PC1 and PC2 of the impedances ZA, ZB, ZC, and ZD during the test period Tt2 converge to a narrower range than the feature quantities PC1 and PC2 of the impedances ZA, ZB, ZC, and ZD during the test period Tt3. The feature quantities PC1 and PC2 of the impedances ZA, ZB, ZC, and ZD during the test period Tt2 are values ​​within the numerical range Rg. This is because there is a high correlation between changes in the impedances ZA, ZB, ZC, and ZD due to the influence of changes in the environment of the transmission line 10A and changes in the posture of the transmission line 10A.

[0181] On the other hand, some of the feature quantities PC1 and PC2 of the impedances ZA, ZB, ZC, and ZD during the test period Tt3 are values ​​outside the numerical range Rg. This is because the partial disconnection of the core wire 1A causes only the impedance ZA to change among the impedances ZA, ZB, ZC, and ZD.

[0182] After calculating the feature quantities PC1 and PC2 of the average impedances ZaveA, ZaveB, and ZaveC, the processing unit 14 compares the calculated feature quantities PC1 and PC2 with a numerical range Rg. The numerical range Rg may be set based on the calculation results of the impedances Z of the multiple core wires 1 before the start of operation of the communication system 301, or may be set based on the measurement results of the impedances Z of the multiple core wires 1 in the test transmission line 10A.

[0183] If the calculated feature quantities PC1 and PC2 are values ​​within the numerical range Rg, the processing unit 14 determines that the core wires 1A, 1B, and 1C are not partially broken. On the other hand, if the calculated feature quantities PC1 and PC2 are values ​​outside the numerical range Rg, the processing unit 14 determines that at least one of the core wires 1A, 1B, and 1C is partially broken.

[0184] In addition, the processing unit 14 may identify the core wire 1 that is partially broken among the core wires 1A, 1B, and 1C based on the comparison results of the feature quantities PC1 and PC2 of the average impedances ZaveA and ZaveB, the feature quantities PC1 and PC2 of the average impedances ZaveB and ZaveC, and the feature quantities PC1 and PC2 of the average impedances ZaveC and ZaveA with the numerical range Rg.

[0185] Specifically, the processing unit 14 determines that the core wire 1A is partially broken when all pairs of feature quantities PC1 and PC2 calculated using the impedance ZA are outside the numerical range Rg. That is, the processing unit 14 determines that the core wire 1A is partially broken when the feature quantities PC1 and PC2 of the average impedances ZaveA and ZaveB and the feature quantities PC1 and PC2 of the average impedances ZaveC and ZaveA are outside the numerical range Rg.

[0186] On the other hand, if all pairs of feature quantities PC1 and PC2 calculated using impedance ZB have values ​​outside the numerical range Rg, the processing unit 14 determines that core wire 1B has a partial open circuit. That is, if the feature quantities PC1 and PC2 of average impedances ZaveA and ZaveB and the feature quantities PC1 and PC2 of average impedances ZaveB and ZaveC have values ​​outside the numerical range Rg, the processing unit 14 determines that core wire 1B has a partial open circuit.

[0187] On the other hand, if all pairs of feature quantities PC1 and PC2 calculated using impedance ZC have values ​​outside the numerical range Rg, the processing unit 14 determines that the core wire 1C has a partial open circuit. That is, if the feature quantities PC1 and PC2 of the average impedances ZaveB and ZaveC and the feature quantities PC1 and PC2 of the average impedances ZaveC and ZaveA have values ​​outside the numerical range Rg, the processing unit 14 determines that the core wire 1C has a partial open circuit.

[0188] In addition, the processing unit 14 may be configured not to perform some of the above-mentioned detection examples 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0189] [Operation Flow] Fig. 21 is a flowchart defining an example of an operation procedure when a communication device according to an embodiment of the present disclosure performs a detection process. Fig. 21 is a flowchart of the above-described detection example 1. For example, the communication device 101 executes the process of Fig. 21 every time the communication device 101 is started up.

[0190] 21, first, the communication device 101 generates a communication signal Sc1 for applying a bending motion BM to the transmission line 10 in the detection period T1, and transmits the communication signal Sc1 to the communication device 111 (step S11).

[0191] Next, during the detection period T1, the communication device 101 outputs measurement signals for M periods to the core wires 1A, 1B, and 1C and receives response signals from the core wires 1A, 1B, and 1C (step S12).

[0192] Next, the communication device 101 measures the amplitude and phase of the response signal. More specifically, the communication device 101 generates amplitude data D3a, which is time-series data on the amplitude of the reflected signal included in the response signal, and phase data D3p, which is time-series data on the phase of the reflected signal (step S13).

[0193] Next, the communication device 101 calculates, as an evaluation value Ev, absolute values ​​ab of the M reflection coefficients rc in the detection period T1 for each core wire 1 (step S14).

[0194] Next, the communication device 101 calculates the statistical value of the evaluation value Ev for each core wire 1. More specifically, the communication device 101 calculates the average value av1 of the M absolute values ​​ab (step S15).

[0195] Next, the communication device 101 compares the corresponding average value av1 with the threshold value Th1 for each core wire 1 (step S16).

[0196] Next, if the average value av1 is less than the threshold value Th1 (YES in step S17), the communication device 101 determines that the corresponding core wire 1 is not partially broken (step S18).

[0197] On the other hand, if the average value av1 is equal to or greater than the threshold value Th1 (NO in step S17), the communication device 101 determines that the corresponding core wire 1 is partially broken (step S19).

[0198] Next, the communication device 101 performs a notification process to notify the administrator of the communication system 301 of the detection result (step S20).

[0199] In Detection Example 5, Detection Example 6, Detection Example 7, and Detection Example 8, a phase difference pd is calculated as the evaluation value Ev in step S14. In Detection Example 2, Detection Example 4, Detection Example 6, and Detection Example 8, instead of step S16, a process is performed in which the absolute value of the difference between the statistical values ​​of the evaluation values ​​Ev for each set of core wires 1 is calculated and the calculated absolute value is compared with a threshold value. In Detection Example 9 and Detection Example 10, an impedance Z is calculated as the evaluation value Ev in step S14. In Detection Example 9, instead of step S16, a process is performed in which regression residuals ReAB, ReBC, and ReCA are calculated and the calculated regression residuals ReAB, ReBC, and ReCA are compared with a threshold value Th9. Furthermore, in detection example 10, instead of step S16, the feature quantities PC1 and PC2 of the average impedances ZaveA, ZaveB, and ZaveC are calculated, and the calculated feature quantities PC1 and PC2 are compared with the numerical range Rg.

[0200] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the measurement unit 13 is configured to receive, from each of the core wires 1A, 1B, and 1C, a response signal including a measurement signal output by the signal output unit 12 and a reflected signal that is a signal obtained by reflecting the measurement signal. However, this is not limited to this. The measurement unit 13 may also be configured to receive a response signal that does not include a measurement signal. In other words, the measurement unit 13 may be configured to receive a reflected signal as a response signal. More specifically, for example, the signal output unit 12 outputs a measurement signal to the core wires 1A, 1B, and 1C via a directional coupler and a communication port 30. The measurement unit 13 receives a response signal that does not include a measurement signal from each of the core wires 1A, 1B, and 1C via the communication port 30 and the directional coupler.

[0201] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the measurement unit 13 is configured to generate digital signals D3A, D3B, and D3C representing the reflected signals by subtracting the components of the digital signal D1 from the digital signals D2A, D2B, and D2C, but this is not limited to this. The measurement unit 13 may also be configured to receive a measurement signal from the signal output unit 12, subtract the components of the measurement signal from the received response signal to generate an analog signal representing the reflected signal, and digitally convert the generated analog signal to generate the digital signals D3A, D3B, and D3C.

[0202] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to calculate, as the evaluation value Ev, the absolute value ab of the reflection coefficient rc and the phase difference pd between the reflected signal and the measurement signal, but this is not limited to this. Instead of the absolute value ab and the phase difference pd, the processing unit 14 may be configured to calculate, as the evaluation value Ev, the reactances XA, XB, and XC of the core wires 1A, 1B, and 1C, the resistances RA, RB, and RC of the core wires 1A, 1B, and 1C, or the impedances ZA, ZB, and ZC of the core wires 1A, 1B, and 1C.

[0203] In addition, the processing unit 14 may be configured to calculate the capacitances CA, CB, and CC of the core wires 1A, 1B, and 1C as the evaluation value Ev when the end of the transmission line 10 on the communication device 111 side is open.

[0204] In addition, the processing unit 14 may be configured to calculate the inductances LA, LB, and LC of the core wires 1A, 1B, and 1C as the evaluation value Ev when the end of the transmission line 10 on the communication device 111 side is connected to a ground node.

[0205] The communication system 301 according to the embodiment of the present disclosure may also include a switching device that switches the state of the end of the transmission line 10 on the communication device 111 side between a first state in which the end is open, a second state in which the end is connected to a ground node, and a third state in which the end is connected to a termination circuit. In this case, the processing unit 14 calculates multiple types of evaluation values ​​Ev by transmitting a control signal to the switching device and switching the state of the end of the transmission line 10 on the communication device 111 side.

[0206] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the communication unit 11 is configured to generate a communication signal Sc1 for applying a bending motion BM in which the bending angle θxy of the transmission line 10 reciprocates between +90° and −90° once during the detection period T1. However, this is not limited to this. The communication unit 11 may be configured to generate a communication signal Sc1 for applying a bending motion or twisting motion other than the bending motion BM. Furthermore, the communication unit 11 may be configured to generate a communication signal Sc1 for applying a bending motion in which the bending angle θxy of the transmission line 10 reciprocates between +90° and −90° multiple times during the detection period T1. Furthermore, the communication unit 11 may be configured to generate a communication signal Sc1 for applying multiple types of bending motions during the detection period T1.

[0207] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to calculate the average values ​​av1 and av2 and the variances va1 and va2 and detect a partial disconnection of the core wire 1 based on the calculated average values ​​av1 and av2 and variances va1 and va2, but this is not limiting. The processing unit 14 may also be configured to detect a partial disconnection of the core wire 1 based on the absolute values ​​ab of M reflection coefficients rc and M phase differences pd during the detection period T1, without calculating the average values ​​av1 and av2 and the variances va1 and va2.

[0208] In addition, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to further detect the degree of progression of damage to the core wire 1, but this is not limitative. The processing unit 14 may be configured not to detect the degree of progression of damage to the core wire 1.

[0209] In addition, in the communication device 101 according to the embodiment of the present disclosure, the communication unit 11 is configured to generate the communication signal Sc1 in accordance with the control pattern Pt received from the administrator, but this is not limited to this. The communication unit 11 may be configured to generate the communication signal Sc1 for applying a predetermined bending operation to the transmission line 10 without receiving the control pattern Pt.

[0210] The above-described embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0211] Each process (each function) in the above-described embodiments is realized by a processing circuit (circuitry) including one or more processors. The processing circuit may be configured as an integrated circuit or the like that combines one or more memories, various analog circuits, and various digital circuits in addition to the one or more processors. The one or more memories store programs (instructions) that cause the one or more processors to execute each of the processes. The one or more processors may execute each of the processes according to the program read from the one or more memories, or may execute each of the processes according to a logic circuit designed in advance to execute each of the processes. The processor may be any of various processors suitable for computer control, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit). Note that the physically separated processors may cooperate with each other to execute the processes. For example, the processors installed in the physically separated computers may cooperate with each other via a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet to execute the processes. The program may be installed into the memory from an external server device or the like via the network, or may be distributed in a state stored on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a semiconductor memory, and then installed into the memory from the recording medium.

[0212] The above description includes the following additional features: [Supplementary Note 1] A detection device comprising: a signal output unit that outputs a measurement signal having a frequency component to a target wire; a measurement unit that receives a response signal from the target wire, the response signal including a signal resulting from reflection of the measurement signal, and measures at least one of the amplitude and phase of the received response signal; a calculation unit that calculates a plurality of evaluation values ​​corresponding to a plurality of postures of the target wire whose posture changes based on the measurement results by the measurement unit; a detection unit that detects damage to a portion of the target wire based on the plurality of evaluation values ​​calculated by the calculation unit; and a control unit that applies a predetermined bending motion to the target wire, wherein the signal output unit outputs the measurement signal to the target wire during the bending motion.

[0213] [Supplementary Note 2] A detection device comprising a processing circuit, wherein the processing circuit outputs a measurement signal having frequency components to a target wire, receives a response signal from the target wire including a signal reflected from the measurement signal, and measures at least one of the amplitude and phase of the received response signal, calculates a plurality of evaluation values ​​corresponding to a plurality of postures of the target wire whose posture changes based on the measurement results of at least one of the amplitude and the phase, and detects damage to a portion of the target wire based on the calculated plurality of evaluation values.

[0214] 1, 1A, 1B, 1C, 1D, 1E, 1F Core wire (target wire) 2 Sheath 3 Wire 4 Insulation layer 10 Transmission line 11 Communication unit 12 Signal output unit 13 Measurement unit 14 Processing unit (calculation unit, detection unit) 15 Storage unit 20 Detection processing unit 30 Communication port 101 Communication device (detection device) 111 Communication device 301 Communication system Bp Bending position t0, td Detection date abA Absolute value av1X, av1Y, av1Z, av2X Average value va1X, va2X Variance Lr1, Lr2 Regression line Re1, Re2 Regression residual Rg Numerical range

Claims

1. A detection device comprising: a signal output unit that outputs a measurement signal having frequency components to a target wire; a measurement unit that receives a response signal from the target wire, the response signal including a signal that is a reflection of the measurement signal, and measures at least one of the amplitude and phase of the received response signal; a calculation unit that calculates, based on the measurement results by the measurement unit, a plurality of evaluation values ​​corresponding to a plurality of postures of the target wire whose posture changes; and a detection unit that detects damage to a portion of the target wire based on the plurality of evaluation values ​​calculated by the calculation unit.

2. The detection device according to claim 1, wherein the detection unit detects damage to a portion of the target line based on a statistical value of the plurality of evaluation values.

3. The detection device according to claim 2, wherein the detection unit detects damage to a portion of the target line based on a comparison result between the statistical value and a predetermined threshold value.

4. The detection device according to claim 2, wherein the detection unit detects damage to a portion of the target line based on changes over time in the statistical value.

5. A detection device as described in any one of claims 1 to 4, wherein the signal output unit outputs the measurement signal to a plurality of the target lines; the measurement unit receives the response signal from each of the plurality of target lines and measures at least one of the amplitude and phase of each of the received response signals; the calculation unit calculates the plurality of evaluation values ​​for each of the target lines; and the detection unit detects damage to a portion of the target line based on the plurality of evaluation values ​​for each of the target lines.

6. The detection device according to claim 5, wherein the detection unit detects damage to a portion of the target line based on the relationship between the plurality of evaluation values ​​for each target line.

7. The detection device described in claim 6, wherein the detection unit calculates a feature value indicating the relationship between the evaluation values ​​for each of the target lines based on the multiple evaluation values ​​for each of the target lines, and detects damage to a portion of the target line based on the feature value.

8. The detection device according to claim 7, wherein the detection unit calculates, as the feature, a regression residual of the plurality of evaluation values ​​for each of the target lines.

9. The detection device according to claim 7, wherein the detection unit calculates the feature amount by dimensionally compressing the plurality of evaluation values ​​for each of the target lines.

10. The detection device described in claim 6, wherein the detection unit calculates a statistical value of the plurality of evaluation values ​​for each of the target lines, and identifies the target lines among the plurality of target lines that are partially damaged based on the comparison results of each of the statistical values.

11. The detection device according to any one of claims 1 to 10, further comprising a control unit for controlling the attitude of the target line, and capable of setting a control pattern for the attitude by the control unit.

12. A detection device according to any one of claims 1 to 11, wherein the detection unit further detects the degree of progress of damage to the target wire.

13. A detection method for a detection device, comprising the steps of: outputting a measurement signal having frequency components to a target wire; receiving a response signal from the target wire, the response signal including a signal reflected from the measurement signal, and measuring at least one of the amplitude and phase of the received response signal; calculating a plurality of evaluation values ​​corresponding to a plurality of postures of the target wire, whose posture changes, based on the measurement results of at least one of the amplitude and the phase; and detecting damage to a portion of the target wire based on the calculated plurality of evaluation values.

Images