Detection device and detection method

Abstract

This detection device comprises: a signal output unit that outputs measurement signals having frequency components to a plurality of bundled target lines; a measurement unit that receives, from each of the plurality of target lines, response signals including signals that are reflections of the measurement signals, and measures at least one among the amplitude and the phase of each of the received response signals; a calculation unit that calculates a plurality of evaluation values respectively corresponding to the plurality of target lines on the basis of the results of measurements by the measurement unit, and calculates feature amounts on the basis of the plurality of calculated evaluation values; and a detection unit that detects bending angles of the target lines on the basis of the feature amounts calculated by the calculation unit.

Description

Detection device and detection method

[0001] This application claims priority from Japanese Patent Application No. 2024-61359, filed April 5, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0002] Patent Document 1 (WO 2023 / 145617) discloses the following detection device: That is, the detection device 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 including a signal resulting from reflection of the measurement signal from the target wire and measures at least one of the amplitude and phase of the received response signal, and a detection unit that calculates an evaluation value based on the measurement result by the measurement unit and detects a change in the degree of curvature of the target wire based on a change over time in the calculated evaluation value.

[0003] International Publication No. 2023 / 145617

[0004] The detection device disclosed herein includes a signal output unit that outputs a measurement signal having frequency components to a plurality of bundled target wires; a measurement unit that receives response signals from each of the plurality of target wires, the response signals including signals reflected from the measurement signal, and measures at least one of the amplitude and phase of each of the received response signals; a calculation unit that calculates a plurality of evaluation values ​​corresponding to each of the plurality of target wires based on the measurement results by the measurement unit, and calculates feature quantities based on the calculated plurality of evaluation values; and a detection unit that detects the bending angle of the target wires based on the feature quantities 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 bent state of the transmission line used in the communication system according to the embodiment of the present disclosure. FIG. 5 is a diagram illustrating a bending radius of the transmission line used in the communication system according to the embodiment of the present disclosure. FIG. 6 is a diagram illustrating a configuration of a communication device according to an embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example of impedance calculated by a processing unit in the communication device according to the embodiment of the present disclosure. FIG. 8 is a diagram illustrating an example of impedance calculated by a processing unit in the communication device according to the embodiment of the present disclosure. FIG. 9 is a diagram illustrating an example of impedance calculated by a processing unit in the communication device according to the embodiment of the present disclosure. FIG. 10 is a diagram illustrating an example of a PLS feature Fv1 calculated by a processing unit in the communication device according to the embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example of a detection result of a bending angle θxy by a processing unit in the communication device according to the embodiment of the present disclosure. Fig. 12 is a diagram illustrating an example of a detection result of a bending angle θxy by a processing unit in a communication device according to an embodiment of the present disclosure. Fig. 13 is a diagram illustrating an example of a detection result of a bending angle θxy by a processing unit in a communication device according to an embodiment of the present disclosure. Fig. 14 is a diagram illustrating an example of a detection result of a bending angle θxy by a processing unit in a communication device according to an embodiment of the present disclosure. Fig. 15 is a diagram illustrating an example of a count result of the number of bends by a processing unit in a communication device according to an embodiment of the present disclosure. Fig. 16 is a flowchart defining an example of an operation procedure when a communication device according to an embodiment of the present disclosure performs detection processing.

[0007] Conventionally, techniques have been proposed for detecting the degree of bending of a transmission line or the like.

[0008] [Problem to be Solved by the Present Disclosure] There is a demand for a technology that can detect the bending angle of a target wire with higher accuracy than the technology described in Patent Document 1.

[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 the bending angle of a target wire with higher accuracy.

[0010] Effect of the Present Disclosure According to the present disclosure, the bending angle of a target line can be detected with higher accuracy.

[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 frequency components to a plurality of bundled target wires, a measurement unit that receives, from each of the plurality of target wires, response signals including signals resulting from reflection of the measurement signal, and measures at least one of the amplitude and the phase of each of the received response signals, a calculation unit that calculates, based on measurement results by the measurement unit, a plurality of evaluation values ​​corresponding to each of the plurality of target wires, and calculates feature amounts based on the calculated plurality of evaluation values, and a detection unit that detects the bending angle of the target wires based on the feature amounts calculated by the calculation unit.

[0012] With this configuration, the feature values ​​are calculated based on multiple evaluation values ​​corresponding to multiple target lines that are subjected to different loads due to bending, and the bending angle can be detected more accurately based on the calculated feature values. Therefore, the bending angle of the target line can be detected with higher accuracy.

[0013] (2) In the above (1), the calculation unit may calculate the feature amount by dimensionally compressing each of the evaluation values.

[0014] With this configuration, it is possible to calculate a feature amount that is highly correlated with, for example, the bending angle based on a plurality of evaluation values, and therefore it is possible to detect the bending angle with higher accuracy based on the calculated feature amount.

[0015] (3) In the above (1), the calculation unit may calculate the feature amount based on a comparison result of the evaluation values.

[0016] With this configuration, it is possible to calculate, for example, a feature value indicating the difference in the load applied to each target line based on the comparison results of each evaluation value, and therefore it is possible to detect the bending angle with higher accuracy based on the calculated feature value.

[0017] (4) In any one of (1) to (3) above, the detection unit may detect the number of bends of the target line based on the detection result of the bending angle.

[0018] With this configuration, for example, it is possible to estimate the degree of deterioration of the target wire based on the detection result of the number of bends.

[0019] (5) In any of the above (1) to (4), the detection unit may detect the bending angle using a learning model created by machine learning the relationship between the bending angle and the feature amount.

[0020] With this configuration, the bending angle of the target wire can be detected easily and accurately.

[0021] (6) In any of (1) to (5) above, the calculation unit may calculate a plurality of types of the feature amounts, and the detection unit may detect the bending angle based on the plurality of types of the feature amounts.

[0022] With this configuration, the bending angle can be detected with higher accuracy based on the various feature amounts obtained based on the evaluation values.

[0023] (7) In any of (1) to (6) above, the detection unit may create time series data of the bending angle, and calculate an angular velocity of the bending motion of the target line based on the time series data.

[0024] With this configuration, it is possible to detect the bending state of the target line in more detail.

[0025] (8) In any one of (1) to (7) above, the detection unit may further detect a bending direction of the target line based on the feature amount.

[0026] With this configuration, it is possible to distinguish between a state in which the target line is bent in a first direction and a state in which the target line is bent in a second direction opposite to the first direction on the bending plane of the target line. Therefore, for example, even if the normal bending direction of the target line is only the first direction, it is possible to detect bending of the target line in the second direction for an unauthorized purpose. Furthermore, based on the bending direction detection result, it is possible to accurately count the number of times the target line is bent back and forth between the angle in the first direction and the angle in the second direction.

[0027] (9) In any of (1) to (8) above, the calculation unit may calculate three or more evaluation values ​​corresponding to three or more of the target lines, respectively, and calculate the feature amount based on the calculated evaluation values.

[0028] With this configuration, the bending angle of the target wire can be detected with higher accuracy.

[0029] (10) In the above (9), the detection unit may detect the bending angles of the target line in a plurality of bending planes.

[0030] With this configuration, the bending angles of the target line bent in a plurality of bending planes can be detected with higher accuracy.

[0031] (11) In any of (1) to (10) above, the target wire may be bent at a bending radius equal to or greater than the outer diameter of the target wire, and the detection unit may detect the bending angle of the target wire bent at the bending radius.

[0032] In a real environment, the target wire is often bent with a bending radius equal to or greater than the outer diameter, and with this configuration, the bending angle of the target wire in a real environment can be detected with higher accuracy.

[0033] (12) A 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 plurality of bundled target wires; receiving response signals from the plurality of target wires, the response signals including signals reflected from the measurement signal; measuring at least one of the amplitude and the phase of each of the received response signals; calculating a plurality of evaluation values ​​corresponding to the plurality of target wires based on the measurement results of at least one of the amplitude and the phase; calculating a feature value based on the calculated evaluation values; and detecting a bending angle of the target wire based on the calculated feature value.

[0034] This method calculates feature values ​​based on multiple evaluation values ​​corresponding to multiple target lines that are subjected to different loads due to bending, and the bending angle can be detected more accurately based on the calculated feature values. Therefore, the bending angle of the target line can be detected with higher accuracy.

[0035] 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.

[0036] [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.

[0037] 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.

[0038] 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. The communication device 101 transmits a communication signal to the communication device 111. The communication device 111 operates an actuator (not shown) or the like in accordance with the communication signal received from the communication device 101. The communication system 301 may also be used, for example, in a home network.

[0039] 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.

[0040] Referring to FIG. 2 , the transmission line 10 includes a plurality of core wires 1 and a sheath 2. Each core wire 1 is covered with a coating layer (not shown) and is insulated from the other core wires 1. The conductor portion of the core wire 1 may be a single core or a bundle of multiple wires. The multiple core wires 1 are bundled 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 θ. The space between the core wires 1 and the sheath 2 may be filled with an insulator. 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 multiple parallel wires may or may not be parallel to each other.

[0041] 3 and 4 are diagrams 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 longitudinal 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. Fig. 4 illustrates a state in which the transmission line 10 is bent in the negative X direction in the XY plane.

[0042] 3 and 4 , for example, the transmission line 10 and the core wire 1 are 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 is taken to be 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 is taken to be a negative value.

[0043] FIG. 5 is a diagram illustrating the bending radius of a transmission line used in a communication system according to an embodiment of the present disclosure. Referring to FIG. 5 , the outer diameter Dm of the transmission line 10 is, for example, 7.5 mm. For example, the transmission line 10 is bent in a real environment with a bending radius Rad that is equal to or greater than the outer diameter Dm. The upper limit of the bending radius Rad of the transmission line 10 in a real environment may be 20 times the outer diameter Dm, 15 times the outer diameter Dm, 10 times the outer diameter Dm, 6 times the outer diameter Dm, or 5 times the outer diameter Dm. Note that the bending radius Rad in a real environment may be 5 mm or more and 15 mm or less, regardless of the outer diameter Dm. Here, the bending radius Rad is the inner radius of the bend of the transmission line 10, i.e., the radius of a circle Cp that is tangent to the transmission line 10 at the bending position Bp.

[0044] The transmission line 10 may include a spiral restraining material instead of the sheath 2 as a member for bundling the core wires 1, or may include a plurality of binding bands provided at intervals along the length of the transmission line 10. Any one of the plurality of binding bands bundles the core wires 1 at the bending position Bp.

[0045] The communication device 101 functions as a detection device and performs a detection process to detect the bending angle θxy of the transmission line 10, that is, the bending angle θxy of the core wire 1.

[0046] [Problem] A technology capable of detecting the bending angle θ of the transmission line 10 with higher accuracy is desired. More specifically, fatigue deterioration of the transmission line 10 progresses depending on the bending angle θ and the number of bending times, and the line may break. Furthermore, the transmission line 10 may be bent at a bending angle that exceeds the bending resistance of the transmission line 10 or may be bent for an improper purpose. A technology capable of checking the state of the transmission line 10 is desired in order to accurately estimate the degree of progression of fatigue deterioration of the transmission line 10 and to take appropriate measures, such as issuing a warning to a user, when the transmission line 10 is not being used normally and safely.

[0047] However, the conventional technique of detecting the bending angle θ based on the electrical characteristics such as the impedance of the transmission line 10 may not be able to detect the bending angle θ with high accuracy.

[0048] Furthermore, for example, the change in the electrical characteristics of the core wire 1 caused by bending the transmission line 10 90 degrees in the positive X direction is roughly equal to the change in the electrical characteristics of the core wire 1 caused by bending the transmission line 10 90 degrees in the negative X direction. Therefore, it is difficult to distinguish between a state in which the transmission line 10 is bent in the positive X direction and a state in which the transmission line 10 is bent in the negative X direction based on the electrical characteristics of the core wire 1. For this reason, with conventional technology, it may be difficult to accurately check the state of the transmission line 10.

[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. 6 is a diagram illustrating the configuration of a communication device according to an embodiment of the present disclosure. Referring to FIG. 6, 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 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] 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.

[0052] (Communication Unit) The communication unit 11 periodically or irregularly generates a communication signal addressed to the communication device 111 and transmits the generated communication signal to the communication device 111 via the communication port 30 and the transmission line 10. The communication unit 11 also receives a communication signal from the communication device 111 via the communication port 30 and the transmission line 10.

[0053] (Signal Output Unit) The signal output unit 12 outputs a measurement signal having a frequency component to multiple core wires 1 in the transmission line 10. For example, the signal output unit 12 outputs an AC signal, a pulse signal, or a frequency sweep signal as the measurement signal to core wires 1A, 1B, and 1C, which are three predetermined core wires 1 in the transmission line 10. 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 from the communication unit 11 to the communication device 111, or may be core wires 1 used to transmit a communication signal from the communication device 111 to the communication unit 11. For example, any two of the core wires 1A, 1B, and 1C are core wires 1 located diagonally along the X direction in the cross section of the transmission line 10. Note that the signal output unit 12 may be configured to output a measurement signal to four or more core wires 1.

[0054] The signal output unit 12 outputs a measurement signal having a frequency band different from the frequency band of the communication signal transmitted by the communication unit 11 via the transmission line 10 to the core wires 1A, 1B, and 1C via the communication port 30. In other words, the communication device 101 frequency-division multiplexes the communication signal and the measurement signal.

[0055] More specifically, during a detection period T1, which is a period during which the communication device 101 is powered on, the signal output unit 12 outputs measurement signals in parallel to the core wires 1A, 1B, and 1C via the communication port 30. Note that the signal output unit 12 may be configured to output the measurement signals to the core wires 1A, 1B, and 1C via the communication port 30 in a time-division manner during the detection period T1.

[0056] 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 of 2 or greater.

[0057] 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 continuously output measurement signals to the core wires 1A, 1B, and 1C. More specifically, the signal output unit 12 includes a DA (Digital to Analog) conversion unit. 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 conversion unit, converts the digital signal D1 to analog using the DA conversion unit, and outputs the generated measurement signal 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.

[0058] 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.

[0059] (Measurement Unit) The measurement unit 13 receives, from each of the core wires 1A, 1B, and 1C, a response signal including a signal resulting from reflection of the measurement signal, and measures the amplitude and phase of each of the received response signals. For example, the measurement unit 13 receives, from each of the core wires 1A, 1B, and 1C via the communication port 30, a response signal including the measurement signal output by the signal output unit 12 and a reflected signal resulting from reflection of the measurement signal.

[0060] More specifically, during the detection period T1, the measurement unit 13 receives the response signals from the core wires 1A, 1B, and 1C via the communication port 30. For example, the measurement unit 13 performs preprocessing using a low-pass filter or the like to remove noise contained in the response signals.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] (Processing Unit) The processing unit 14 calculates evaluation values ​​EvA, EvB, and EvC corresponding to the core wires 1A, 1B, and 1C, respectively, based on the measurement results by the measurement unit 13, and calculates a feature amount Fv based on the calculated evaluation values ​​EvA, EvB, and EvC. The processing unit 14 detects the bending angle θxy based on the calculated feature amount Fv. Hereinafter, each of the evaluation values ​​EvA, EvB, and EvC will also be referred to as an evaluation value Ev.

[0067] For example, the processing unit 14 further detects the bending directions of the core wires 1A, 1B, and 1C based on the feature quantity Fv. More specifically, the processing unit 14 detects whether the bending direction of the transmission line 10 is the positive X direction or the negative X direction. That is, the processing unit 14 detects the bending angle θxy in the angle range from −180° to +180°.

[0068] (1) Calculation of Evaluation Value Ev For example, the processing unit 14 calculates the impedances ZA, ZB, and ZC of the core wires 1A, 1B, and 1C as evaluation values ​​EvA, EvB, and EvC, respectively.

[0069] More specifically, the 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 the signal output unit 12.

[0070] The processing unit 14 calculates a value VA by dividing the amplitude data D3aA received from the measurement unit 13 by the amplitude data D1a, for example, for each period of the measurement signal, i.e., for every N samples. More specifically, the processing unit 14 calculates a value VA by dividing the average value of the N sample values ​​of the amplitude data D3aA by the average value of the N sample values ​​of the amplitude data D1a. The processing unit 14 calculates a reflection coefficient rcA based on the calculated value VA. The processing unit 14 then calculates an impedance ZA according to the following equation (1):

[0071] 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.

[0072] Furthermore, the processing unit 14 calculates a value VB 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 every N samples. More specifically, the processing unit 14 calculates a value VB by dividing the average value of the N sample values ​​of the amplitude data D3aB by the average value of the N sample values ​​of the amplitude data D1a. The processing unit 14 calculates a reflection coefficient rcB based on the calculated value VB. The processing unit 14 then calculates an impedance ZB according to the following equation (2):

[0073] Furthermore, the processing unit 14 calculates a value VC 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 samples. More specifically, the processing unit 14 calculates a value VC by dividing the average value of the N sample values ​​of the amplitude data D3aC by the average value of the N sample values ​​of the amplitude data D1a. The processing unit 14 calculates a reflection coefficient rcC based on the calculated value VC. The processing unit 14 then calculates the impedance ZC according to the following equation (3):

[0074] 7 to 9 are diagrams illustrating an example of impedance calculated by a processing unit in a communication device according to an embodiment of the present disclosure. In each of the diagrams, the horizontal axis represents time (seconds) and the vertical axis represents impedance (Ω). Each of the diagrams illustrates the time variations of impedances ZA, ZB, and ZC when a bending test BT is performed in which the transmission line 10 is repeatedly bent alternately from +90° to −90° along the X direction in an XY plane.

[0075] 7 to 9, the processing unit 14 calculates the impedances ZA, ZB, and ZC at calculation timings according to a predetermined calculation period Cm. The calculation period Cm is set to a value shorter than the period of bending expected in the transmission line 10, for example, a value corresponding to the period of the measurement signal.

[0076] (2) Calculation of Feature Value Fv The processing unit 14 calculates the feature value Fv by dimensionally compressing the evaluation values ​​EvA, EvB, and EvC.

[0077] 10 is a diagram illustrating an example of a PLS feature Fv1 calculated by a processing unit in a communication device according to an embodiment of the present disclosure. In FIG. 10, the horizontal axis represents time [seconds], and the vertical axis represents a PLS (Partial Least Squares Regression) feature. FIG. 10 illustrates a change over time in the PLS feature Fv1 calculated based on the impedances ZA, ZB, and ZC shown in FIGS. 7 to 9.

[0078] Referring to FIG. 10, for example, each time the processing unit 14 calculates the impedances ZA, ZB, and ZC, it calculates a PLS feature Fv1, which is a feature Fv obtained by dimensionally compressing the impedances ZA, ZB, and ZC according to PLS.

[0079] More specifically, the processing unit 14 extracts the PLS feature Fv1 from the impedances ZA, ZB, and ZC so that the covariance between the bending angle θxy, which is the objective variable, and the PLS feature Fv1 is maximized.

[0080] (3) Detection of bending angle θxy For example, the storage unit 15 stores a learning model Md1. The learning model Md1 is created in advance by machine learning the relationship between the bending angle θxy and the PLS feature Fv1 extracted from the mutually synchronized impedances ZA, ZB, and ZC using a machine learning method such as linear regression and deep learning. The learning model Md1 may be created by the processing unit 14 or by a device external to the communication device 101.

[0081] Each time the processing unit 14 extracts the PLS feature Fv1, the processing unit 14 provides the extracted PLS feature Fv1 to the learning model Md1 in the storage unit 15, thereby obtaining the bending angle θxy.

[0082] Fig. 11 is a diagram showing an example of the detection result of the bending angle θxy by the processing unit in the communication device according to the embodiment of the present disclosure. In Fig. 11, the horizontal axis represents time [seconds], and the vertical axis represents the bending angle θxy [degrees]. The solid line in Fig. 11 represents the time-series data Dt of the bending angle θxy detected by the processing unit 14. The dashed line in Fig. 11 represents the actual bending angle θxy in the bending test BT described above.

[0083] 11 , the processing unit 14 generates time-series data Dt of the bending angle θxy. More specifically, every time the processing unit 14 acquires a bending angle θxy, the processing unit 14 updates the time-series data Dt by storing the acquired bending angle θxy in the storage unit 15. The detection result of the bending angle θxy by the processing unit 14 is approximately equal to the actual bending angle θxy of the transmission line 10, and can distinguish between bending angles θxy in the positive X direction and bending angles θxy in the negative X direction.

[0084] 12 to 14 are diagrams illustrating an example of the detection results of the bending angle θxy by the processing unit in the communication device according to the embodiment of the present disclosure. The interpretation of FIGS. 12 to 14 is the same as that of FIG. 11 . FIG. 12 illustrates the detection results of the bending angle θxy in the bending test BT when the bending radius Rad is set to 15 mm, which is twice the outer diameter Dm. FIG. 13 illustrates the detection results of the bending angle θxy in the bending test BT when the bending radius Rad is set to 10 mm, which is approximately 1.3 times the outer diameter Dm. FIG. 14 illustrates the detection results of the bending angle θxy in the bending test BT when the bending radius Rad is set to 5 mm, which is approximately 0.67 times the outer diameter Dm.

[0085] 12 to 14, the detection result of the bending angle θxy by the processing unit 14 is approximately equal to the actual bending angle θxy of the transmission line 10, regardless of the bending radius Rad, and it is possible to distinguish between the bending angle θxy in the positive X direction and the bending angle θxy in the negative X direction.

[0086] For example, the processing unit 14 calculates the angular velocity Bv of the core wires 1A, 1B, and 1C in the bending motion based on the time-series data Dt. More specifically, the processing unit 14 calculates the angular velocity Bv by differentiating the time-series data Dt.

[0087] 15 is a diagram illustrating an example of the results of counting the number of bending operations by a processing unit in a communication device according to an embodiment of the present disclosure. In FIG. 15, the horizontal axis represents time (seconds), and the vertical axis represents the angle difference (degrees) and the number of bending operations. FIG. 15 illustrates the angle difference Dd of the bending angle θxy and the count value Cv of the number of bending operations.

[0088] Referring to Figure 15, each time the processing unit 14 provides the PLS feature Fv1 to the learning model Md1 to obtain a bending angle θxy, it calculates the angle difference Dd, which is the difference between the bending angle θxy and the bending angle θxy obtained immediately before.

[0089] When the angular difference Dd transitions from a negative value to a positive value and then from a positive value to a negative value, the processing unit 14 determines that the bending angle θxy of the transmission line 10 in the XY plane has made one round trip between +90° and −90°, and counts up the count value Cv of the number of bends. For example, when the count value Cv exceeds a predetermined value, the processing unit 14 performs notification processing to notify the user of a predetermined warning, for example.

[0090] [Operation Flow] FIG. 16 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.

[0091] Referring to Figure 16, first, when the power of the communication device 101 is turned on, for example, the communication device 101 starts outputting measurement signals to the core wires 1A, 1B, and 1C and receiving response signals from the core wires 1A, 1B, and 1C (step S11).

[0092] Next, the communication device 101 waits for the timing to calculate the impedances ZA, ZB, and ZC (NO in step S12), and when the calculation timing arrives (YES in step S12), it 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).

[0093] Next, the communication device 101 calculates the impedances ZA, ZB, and ZC based on the amplitude data D1a, which is time-series data on the amplitude of the measurement signal, the phase data D1p, which is time-series data on the phase of the measurement signal, the amplitude data D3a, and the phase data D3p (step S14).

[0094] Next, the communication device 101 calculates a PLS feature Fv1, which is a feature Fv obtained by dimensionally compressing the calculated impedances ZA, ZB, and ZC (step S15).

[0095] Next, the communication device 101 obtains the bending angle θxy by providing the PLS feature Fv1 to the learning model Md1 (step S16).

[0096] Next, the communication device 101 calculates an angle difference Dd, which is the difference between the bending angle θxy and the bending angle θxy acquired immediately before (step S17).

[0097] Next, if the angular difference Dd transitions from a positive value to a negative value (YES in step S18), the communication device 101 counts up the bend count value Cv (step S19) and waits for a new timing to calculate the impedances ZA, ZB, and ZC (NO in step S12).

[0098] On the other hand, if the angular difference Dd does not transition from a positive value to a negative value (NO in step S18), the communication device 101 waits for a new timing for calculating the impedances ZA, ZB, and ZC without counting up the count value Cv (NO in step S12).

[0099] In the communication device 101 according to the embodiment of the present disclosure, the signal output unit 12 is configured to output to the core wires 1A, 1B, and 1C, during the detection period T1, which is the period during which the communication device 101 is powered on, a measurement signal in a frequency band different from the frequency band of the communication signal transmitted by the communication unit 11 via the transmission line 10, but this is not limited to this. The signal output unit 12 may be configured to output to the core wires 1A, 1B, and 1C, a measurement signal in a frequency band that includes part or all of the frequency band of the communication signal, during the period during which the communication device 101 is powered on and the communication unit 11 does not transmit the communication signal.

[0100] 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.

[0101] In addition, in the communication device 101 according to the embodiment of the present disclosure, the measurement unit 13 is configured to generate the digital signals D3A, D3B, and D3C representing the reflected signals by subtracting 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 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.

[0102] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the signal output unit 12 is configured to output measurement signals to the core wires 1A, 1B, and 1C, but this is not limiting. The signal output unit 12 may be configured to output measurement signals to two core wires 1. In this case, the measurement unit 13 receives response signals, including signals resulting from reflection of the measurement signals, from each of the two core wires 1 and measures the amplitude and phase of each of the received response signals. The processing unit 14 calculates two evaluation values ​​corresponding to the two core wires 1, respectively, based on the measurement results by the measurement unit 13, and calculates feature quantities based on the calculated evaluation values. The processing unit 14 detects the bending angle θ of the two core wires 1 based on the calculated feature quantities.

[0103] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, any two of the core wires 1A, 1B, and 1C to which measurement signals are output are core wires 1 located diagonally in the X direction in the cross section of the transmission line 10. However, this is not limited to this. The core wires 1A, 1B, and 1C do not have to be core wires 1 located diagonally in the X direction in the cross section of the transmission line 10. Here, the amount of change in the evaluation value Ev corresponding to that core wire 1 caused by bending the transmission line 10 varies depending on the position of the core wire 1 in the transmission line 10. By selecting a core wire 1 that has a large amount of change in the evaluation value Ev caused by bending the transmission line 10 as the core wire 1 to which measurement signals are output, the detection accuracy of the bending angle θ can be improved. Furthermore, by selecting a larger number of core wires 1 as the core wires 1 to which measurement signals are output, it is possible to select core wires 1 that have a large amount of change in the evaluation value Ev caused by bending the transmission line 10, thereby improving the detection accuracy of the bending angle θ.

[0104] Furthermore, although the communication device 101 according to the embodiment of the present disclosure is configured to detect the bend angle θ of the core wires 1A, 1B, and 1C, this is not limiting. The communication device 101 may also be configured to detect the bend angle θ of multiple bundled single wires. More specifically, the signal output unit 12 outputs a measurement signal to the multiple single wires. The measurement unit 13 receives response signals, including signals resulting from reflection of the measurement signal, from each of the multiple single wires and measures the amplitude and phase of each received response signal. The processing unit 14 calculates multiple evaluation values ​​corresponding to the multiple single wires based on the measurement results by the measurement unit 13 and calculates feature quantities based on the calculated evaluation values. The processing unit 14 detects the bend angle θ of the multiple single wires based on the calculated feature quantities. At least one of the multiple single wires may be a dedicated line not used for communication by the communication unit 11.

[0105] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to calculate the angular velocity Bv, but this is not limiting. The processing unit 14 may be configured not to calculate the angular velocity Bv.

[0106] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the storage unit 15 is configured to store the learning model Md1, but this is not limited to this. Instead of the learning model Md1, the storage unit 15 may be configured to store a learning model Md2 created by machine learning the relationship between the bending angle θxy and the impedances ZA, ZB, and ZC. In this case, the processing unit 14 obtains the bending angle θxy by providing the impedances ZA, ZB, and ZC to the learning model Md2.

[0107] In addition, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to detect the bending directions of the core wires 1A, 1B, and 1C, but this is not limitative. The processing unit 14 may be configured not to detect the bending directions of the core wires 1A, 1B, and 1C.

[0108] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to detect the bending angle θxy, but this is not limited thereto. The processing unit 14 may be configured to detect the bending angle θyz, which is the bending angle θ of the transmission line 10 in the YZ plane, instead of the bending angle θxy. More specifically, the processing unit 14 extracts the PLS feature Fv2 from the impedances ZA, ZB, and ZC so that the covariance between the bending angle θzy and the PLS feature Fv2 is maximized. The storage unit 15 stores a learning model Md3 created by machine learning the relationship between the bending angle θyz and the PLS feature Fv2. The processing unit 14 obtains the bending angle θyz by providing the PLS feature Fv2 to the learning model Md3.

[0109] The processing unit 14 may also be configured to detect the bending angles θ of the core wires 1A, 1B, and 1C on multiple bending planes. That is, the processing unit 14 may be configured to detect the bending angle θyz in addition to the bending angle θxy. More specifically, the processing unit 14 extracts the PLS feature Fv3 from the impedances ZA, ZB, and ZC so that the covariance between the bending angles θxy and θzy and the PLS feature Fv3 is maximized. The storage unit 15 stores a learning model Md4 created by machine learning the relationship between the bending angles θxy and θyz and the PLS feature Fv3. The processing unit 14 acquires the bending angles θxy and θyz by providing the PLS feature Fv3 to the learning model Md4.

[0110] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to calculate the PLS feature Fv1 by dimensionally compressing the evaluation values ​​EvA, EvB, and EvC, but this is not limited to this. The processing unit 14 may be configured to calculate the feature Fv based on the comparison result of the evaluation values ​​EvA, EvB, and EvC, instead of the PLS feature Fv1. More specifically, the processing unit 14 calculates, as the feature Fv, a difference Dab between the evaluation values ​​EvA and EvB, a difference Dbc between the evaluation values ​​EvB and EvC, and a difference Dca between the evaluation values ​​EvC and EvA, and detects the bending angle θ based on the calculated differences Dab, Dbc, and Dca. Alternatively, the processing unit 14 calculates, as the feature Fv, the ratio Rab between the evaluation value EvA and the evaluation value EvB, the ratio Rbc between the evaluation value EvB and the evaluation value EvC, and the ratio Rca between the evaluation value EvC and the evaluation value EvA, and detects the bending angle θ based on the calculated ratios Rab, Rbc, and Rca.

[0111] Furthermore, the processing unit 14 may be configured to calculate a plurality of types of feature quantities Fv and detect the bending angle θ based on the plurality of types of feature quantities Fv. More specifically, the processing unit 14 calculates the PLS feature quantity Fv1, the differences Dab, Dbc, Dca, and the ratios Rab, Rbc, and Rca as the feature quantities Fv, and detects the bending angle θ based on the PLS feature quantity Fv1, the differences Dab, Dbc, Dca, and the ratios Rab, Rbc, and Rca.

[0112] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to calculate the impedances ZA, ZB, and ZC as the evaluation values ​​EvA, EvB, and EvC, respectively, but this is not limited thereto. The processing unit 14 may be configured to calculate the reactances XA, XB, and XC of the core wires 1A, 1B, and 1C instead of the impedances ZA, ZB, and ZC as the evaluation values ​​EvA, EvB, and EvC, or may be configured to calculate the resistances RA, RB, and RC of the core wires 1A, 1B, and 1C, or may be configured to calculate the phase differences pdA, pdB, and pdC between the measurement signal and the reflected signal in the core wires 1A, 1B, and 1C, or may be configured to calculate the absolute values ​​ArcA, ArcB, and ArcC of the reflection coefficients rc of the core wires 1A, 1B, and 1C.

[0113] 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 values ​​EvA, EvB, and EvC when the end of the transmission line 10 on the communication device 111 side is open.

[0114] In addition, when the end of the transmission line 10 on the communication device 111 side is connected to a ground node, 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 values ​​EvA, EvB, and EvC.

[0115] Furthermore, the communication system 301 according to the embodiment of the present disclosure may 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 ​​EvA, EvB, and EvC 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.

[0116] Furthermore, in the communication device 101 according to the embodiment of the present disclosure, the processing unit 14 is configured to determine that the bending angle θxy of the transmission line 10 in the XY plane has made one round trip between +90° and −90° when the angular difference Dd transitions from a negative value to a positive value and then from a positive value to a negative value, but this is not limited to this. The processing unit 14 may be configured to use a value obtained by differentiating the bending angle θxy instead of the angular difference Dd.

[0117] Furthermore, the processing unit 14 may be configured to count up the count value Cv when the value of the cross-correlation between the time-series data Dt of the actual bending angle θxy when a predetermined bending test is performed on the transmission line 10 and the generated time-series data Dt becomes equal to or greater than a predetermined value.

[0118] 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.

[0119] 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.

[0120] The above description includes the following additional features: [Supplementary Note 1] A detection device comprising a processing circuit, wherein the processing circuit outputs a measurement signal having a frequency component to a plurality of bundled target wires, receives response signals from each of the plurality of target wires, the response signals including signals resulting from reflection of the measurement signal, and measures at least one of an amplitude and a phase of each of the received response signals, calculates a plurality of evaluation values ​​corresponding to each of the plurality of target wires based on the measurement results of at least one of the amplitude and the phase, calculates a feature amount based on each of the calculated evaluation values, and detects a bending angle of the target wire based on the calculated feature amount.

[0121] REFERENCE SIGNS LIST 1, 1A, 1B, 1C Core wire (target wire) 2 Sheath 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 θxy Bending angle ZA, ZB, ZC Impedance (evaluation value) Ev1 PLS feature (feature) Dt Time series data Dd Angle difference Cv Count value

Claims

1. A detection device comprising: a signal output unit that outputs a measurement signal having frequency components to a plurality of bundled target wires; a measurement unit that receives response signals from each of the plurality of target wires, the response signals including signals resulting from reflection of the measurement signal, and measures at least one of the amplitude and phase of each of the received response signals; a calculation unit that calculates a plurality of evaluation values ​​corresponding to each of the plurality of target wires based on the measurement results by the measurement unit, and calculates feature quantities based on the calculated plurality of evaluation values; and a detection unit that detects the bending angle of the target wires based on the feature quantities calculated by the calculation unit.

2. The detection device according to claim 1, wherein the calculation unit calculates the feature quantity by dimensionally compressing each evaluation value.

3. The detection device according to claim 1, wherein the calculation unit calculates the feature amount based on a comparison result of each of the evaluation values.

4. A detection device according to any one of claims 1 to 3, wherein the detection unit detects the number of bends of the target wire based on the detection result of the bending angle.

5. A detection device according to any one of claims 1 to 4, wherein the detection unit detects the bending angle using a learning model created by machine learning the relationship between the bending angle and the feature amount.

6. A detection device according to any one of claims 1 to 5, wherein the calculation unit calculates a plurality of types of feature amounts, and the detection unit detects the bending angle based on the plurality of types of feature amounts.

7. A detection device according to any one of claims 1 to 6, wherein the detection unit creates time series data of the bending angle and calculates the angular velocity of the bending motion of the target line based on the time series data.

8. A detection device according to any one of claims 1 to 7, wherein the detection unit further detects the bending direction of the target line based on the feature amount.

9. A detection device according to any one of claims 1 to 8, wherein the calculation unit calculates three or more evaluation values ​​corresponding to three or more target lines, respectively, and calculates the feature amount based on the calculated evaluation values.

10. The detection device according to claim 9, wherein the detection unit detects the bending angles of the target line in a plurality of bending planes.

11. A detection device according to any one of claims 1 to 10, wherein the target wire is bent at a bending radius equal to or greater than the outer diameter of the target wire, and the detection unit detects the bending angle of the target wire bent at the bending radius.

12. A detection method for a detection device, comprising: a step of outputting a measurement signal having frequency components to a plurality of bundled target wires; a step of receiving, from each of the plurality of target wires, a response signal including a signal resulting from reflection of the measurement signal, and measuring at least one of the amplitude and phase of each of the received response signals; a step of calculating, based on the measurement results of at least one of the amplitude and the phase, a plurality of evaluation values ​​corresponding to each of the plurality of target wires, and calculating a feature amount based on the calculated plurality of evaluation values; and a step of detecting the bending angle of the target wire based on the calculated feature amount.

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