Patent Description:
<CIT> describes an electrical wire/cable disconnection detection method for injecting a high-frequency pulse into an electrical wire or a conductor in a cable, measuring a waveform that reflects this injected high-frequency pulse from the electrical wire or the cable as a reflected pulse, and detecting a disconnection of the wire or the conductor in the electrical cable based on this waveform.

<CIT> shows a cable deterioration diagnosis device with the features of the preamble of claim <NUM>.

The present disclosure provides a device effective in detecting cable deterioration with a simpler configuration.

According to the invention a cable deterioration diagnosis device according to claim <NUM> is provided.

A cable deterioration diagnosis method according to claim <NUM> is also provided.

According to the present disclosure, it is possible to provide a device effective in detecting cable deterioration with a simpler configuration.

An embodiment will be described in detail below with reference to the drawings. In the description, elements which are the same or have the same function are given the same reference numbers, and redundant descriptions thereof are omitted.

A machine system <NUM> illustrated in <FIG> includes a first device <NUM>, a second device <NUM>, a cable <NUM> that connects the first device <NUM> and the second device <NUM>, and a cable deterioration diagnosis device <NUM> that diagnoses a deterioration state of the cable <NUM>.

The second device <NUM> is a device having a movable unit <NUM> that operates while bending the cable <NUM>, and the first device <NUM> is a controller that controls the second device <NUM>. An example of the second device <NUM> is a robot. The robot has a plurality of joints as the movable unit <NUM>.

The second device <NUM> illustrated in <FIG> is an industrial vertical articulated robot, and has a base <NUM>, a rotation section <NUM>, a first arm <NUM>, a second arm <NUM>, a wrist <NUM>, a tip <NUM>, joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, and a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, a sensor <NUM>, and a sensor <NUM>.

The base <NUM> is installed on a floor or the like in a work area. The rotation section <NUM> is mounted on the base <NUM> so as to be rotatable around a vertical axis <NUM>. For example, the second device <NUM> has the joint <NUM> that attaches the rotation section <NUM> to the base <NUM> so as to be rotatable around the axis <NUM>. The first arm <NUM> is connected to the rotation section <NUM> so as to be rotatable around an axis <NUM> that intersects (e.g., is orthogonal to) the axis <NUM>. For example, the second device <NUM> has the joint <NUM> that connects the first arm <NUM> to the rotation section <NUM> so as to be rotatable around the axis <NUM>. The term "intersect" includes in its meaning a twisted relationship such as a so-called three-dimensional intersection. The same applies hereinafter. The first arm <NUM> extends from the rotation section <NUM> along one direction that intersects (e.g., is orthogonal to) the axis <NUM>.

The second arm <NUM> is connected to an end of the first arm <NUM> so as to be rotatable around an axis <NUM> parallel to the axis <NUM>. For example, the second device <NUM> has the joint <NUM> that connects the second arm <NUM> to the first arm <NUM> so as to be rotatable around the axis <NUM>. The second arm <NUM> has an arm base <NUM> extending from an end of the first arm <NUM> along one direction that intersects (e.g., is orthogonal to) the axis <NUM>, and an arm end <NUM> further extending from an end of the arm base <NUM> along the same one direction. The arm end <NUM> is rotatable around an axis <NUM> to the arm base <NUM>. The axis <NUM> intersects (e.g., is orthogonal to) the axis <NUM>. For example, the second device <NUM> has the joint <NUM> that connects the arm end <NUM> to the arm base <NUM> so as to be rotatable around the axis <NUM>.

The wrist <NUM> is connected to an end of the arm end <NUM> so as to be rotatable around an axis <NUM> that intersects (e.g., is orthogonal to) the axis <NUM>. For example, the second device <NUM> has the joint <NUM> that connects the wrist <NUM> to the arm end <NUM> so as to be rotatable around the axis <NUM>. The wrist <NUM> extends from the end of the arm end <NUM> along one direction that intersects (e.g., is orthogonal to) the axis <NUM>. The tip <NUM> is connected to an end of the wrist <NUM> so as to be rotatable around an axis <NUM> that intersects (e.g., is orthogonal to) the axis <NUM>. For example, the second device <NUM> has the joint <NUM> that connects the tip <NUM> to the wrist <NUM> so as to be rotatable around the axis <NUM>.

The actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> drive the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, respectively. The actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> include, for example, electric motors and transmission units (e.g., reduction gears) that transmit power of the electric motors to the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, respectively. For example, the actuator <NUM> drives the joint <NUM> so as to rotate the rotation section <NUM> around the axis <NUM>. The actuator <NUM> drives the joint <NUM> so as to rotate the first arm <NUM> around the axis <NUM>. The actuator <NUM> drives the joint <NUM> so as to rotate the second arm <NUM> around the axis <NUM>. The actuator <NUM> drives the joint <NUM> so as to rotate the arm end <NUM> around the axis <NUM>. The actuator <NUM> drives the joint <NUM> so as to rotate the wrist <NUM> around the axis <NUM>. The actuator <NUM> drives the joint <NUM> so as to rotate the tip <NUM> around the axis <NUM>.

The sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM> detect rotation angles of the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> (or the rotation angles of the rotors of the actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>), respectively. For example, the sensor <NUM> detects a rotation angle of the rotation section <NUM> to the base <NUM>, the sensor <NUM> detects a rotation angle of the first arm <NUM> to the rotation section <NUM>, the sensor <NUM> detects a rotation angle of the second arm <NUM> to the first arm <NUM>, the sensor <NUM> detects a rotation angle of the arm end <NUM> to the arm base <NUM>, the sensor <NUM> detects a rotation angle of the wrist <NUM> to the arm end <NUM>, and the sensor <NUM> detects a rotation angle of the tip <NUM> to the wrist <NUM>. For example, each of the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM> is a rotary encoder, which detects an operating angle of the corresponding joint or the rotor of the actuator based on a signal corresponding to the rotation angle of the corresponding joint or the rotor of the actuator. The sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM> transmit digital signals representing the detection results of the operating angles to the first device <NUM> via the cable <NUM>. For example, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM> transmit the digital signals to the first device <NUM> via serial communication.

The first device <NUM> controls the second device <NUM> based on a predetermined operation program. The operation program includes a plurality of operation commands in time series. Each of the plurality of operation commands includes at least commands for a position, a posture, and a movement speed of the tip <NUM>. The first device <NUM> repeats a control cycle including at least the following processes in a predetermined cycle.

Process <NUM>) Calculate a target position and a target posture of the tip <NUM> based on the operation command.

Process <NUM>) Calculate target angles of the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> by performing inverse motion operations for the target position and the target posture of the tip <NUM>.

Process <NUM>) Control the actuators <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> so that the operating angles of the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> follow the target angles based on the operating angles of the joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> received from the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM>.

The cable <NUM> has a first end <NUM> connected to the first device <NUM> and a second end <NUM> connected to the second device <NUM>, and transmits one or more signals between the first device <NUM> and the second device <NUM>. As illustrated in <FIG>, the cable <NUM> includes a plurality of electrical wires <NUM>, a shield wire <NUM>, an insulating sheath <NUM>, and a connector <NUM>. The plurality of electrical wires <NUM> include one or more signal wires <NUM>, a test signal transmitting wire <NUM>, and a test signal receiving wire <NUM>. Each of the plurality of electrical wires <NUM> is covered with an insulating individual sheath and is insulated from other electrical wires <NUM>. Thus, the test signal transmitting wire <NUM> is independent of the one or more signal wires <NUM>, and the test signal receiving wire <NUM> is independent of the one or more signal wires <NUM> and the test signal transmitting wire <NUM>.

The one or more signal wires <NUM> transmit the one or more signals between the first device <NUM> and the second device <NUM>, respectively. When transmitting the plurality of signals between the first device <NUM> and the second device <NUM>, the plurality of electrical wires <NUM> have a plurality of signal wires <NUM> each corresponding to the plurality of signals. Examples of the plurality of signals include a plurality of digital signals transmitted by the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, the sensor <NUM>, and the sensor <NUM>, respectively. The plurality of electrical wires <NUM> may have a plurality of pairs of signal wires <NUM> each corresponding to the plurality of signals. Each of the plurality of pairs constitutes, for example, a twisted pair, and transmits the corresponding signal as a differential signal. The test signal transmitting wire <NUM> and the test signal receiving wire <NUM> are electrically connected to the cable deterioration diagnosis device <NUM> at the first end <NUM>. The test signal transmitting wire <NUM> and the test signal receiving wire <NUM> are not connected to the second device <NUM> at the second end <NUM>, and are released in a state of being isolated from the surroundings.

The shield wire <NUM> is a net-like conductive member woven so as to cover the plurality of electrical wires <NUM>. The insulating sheath <NUM> is an insulating tube formed so as to cover the shield wire <NUM>.

The connector <NUM> is provided at the first end <NUM>, and has a plurality of conductive terminals <NUM>. The plurality of terminals <NUM> include one or more signal terminals <NUM>, a test signal transmitting terminal <NUM>, and a test signal receiving terminal <NUM>. The one or more signal terminals <NUM> are connected to the one or more signal wires <NUM>, respectively. The test signal transmitting terminal <NUM> is connected to the test signal transmitting wire <NUM>. The test signal receiving terminal <NUM> is connected to the test signal receiving wire <NUM>. When the plurality of electrical wires <NUM> include the plurality of pairs of signal wires <NUM>, the plurality of terminals <NUM> include a plurality of pairs of signal terminals <NUM>, each corresponding to the plurality of pairs of signal wires <NUM>.

The cable deterioration diagnosis device <NUM> diagnoses the deterioration of the cable <NUM>. The term "deterioration" means occurrence of a change in electrical conductivity, imbalance, or the like in the cable <NUM> due to damage. Examples of changes in electrical properties include changes in the electrical resistance and inductance of the individual electrical wires <NUM> and changes in capacitance between two or more electrical wires <NUM>. The electrical properties do not substantially change even when the undamaged cable <NUM> is subjected to a movement such as bending, stretching and the like. On the other hand, damage to the cable <NUM> causes changes in electrical properties. Further, the electrical properties of the cable <NUM> are further changed by applying a movement such as bending and stretching to the damaged portion. Examples of damage to the cable <NUM> include partial or complete disconnection of a conductive core wire of the electrical wire <NUM>, and thinning of the individual sheath for the electrical wire <NUM> or the like. The disconnection of the core wire and the thinning of the individual sheath may be caused by repetitive stresses such as bending, stretching and the like due to the operation of the second device <NUM>. Further, the disconnection of the core wire and the thinning of the individual sheath may also be caused by a sudden stress, such as pinching of the cable <NUM>.

In order to detect deterioration of the one or more signal wires <NUM>, it is conceivable to apply test signals to the one or more signal wires <NUM> themselves, and check responses. However, according to a method of applying the test signals to the one or more signal wires <NUM> themselves, it is necessary to apply a test signal to each of the plurality of signal wires <NUM> when the cable <NUM> has the plurality of signal wires <NUM>. In contrast, the cable deterioration diagnosis device <NUM> is configured to output a wave-like test signal to the test signal transmitting wire <NUM>, extract the received test signal corresponding to the test signal from the signal propagated in the test signal receiving wire <NUM>, and detect the deterioration of the cable <NUM> based on the test signal and the received test signal.

Thus, the deterioration of the cable <NUM> can be detected based on the test signal output to the single test signal transmitting wire <NUM> and the received test signal propagated in the single test signal receiving wire <NUM> regardless of the number of signal wires <NUM>. Therefore, it is effective in detecting the deterioration of the cable <NUM> with a simpler configuration.

For example, the cable deterioration diagnosis device <NUM> includes a main body <NUM> and an adapter <NUM>. The cable deterioration diagnosis device <NUM> includes a main body <NUM> and an adapter <NUM>. The main body <NUM> has a test signal output unit <NUM>, a test signal extraction unit <NUM>, and a deterioration detection unit <NUM> as functional configurations (hereinafter, referred to as "functional blocks").

The test signal output unit <NUM> outputs a wave-like test signal to the test signal transmitting wire <NUM>. According to the invention, the test signal output unit <NUM> outputs a test signal modulated wave, in which the test signal is superimposed on a carrier wave, to the test signal transmitting wire <NUM>.

For example, the test signal output unit <NUM> has a test signal generation unit <NUM>, a carrier wave generation unit <NUM>, and a modulated wave generation unit <NUM> as functional blocks. The test signal generation unit <NUM> generates a wave-like test signal. The waveform of the test signal is not particularly limited. For example, the test signal generation unit <NUM> may generate a square wave test signal, a sawtooth wave test signal, or a sine wave test signal. The carrier wave generation unit <NUM> generates a carrier wave. The waveform of the carrier wave is also not limited particularly limited. For example, the carrier wave generation unit <NUM> may generate a square wave test signal, a sawtooth wave test signal, or a sine wave test signal. The modulated wave generation unit <NUM> generates a test signal modulated wave in which the test signal generated by the test signal generation unit <NUM> is superimposed on the carrier wave generated by the carrier wave generation unit <NUM>, and outputs the test signal modulated wave to the test signal transmitting wire <NUM>.

For example, the modulated wave generation unit <NUM> generates a frequency modulation (FM) modulated wave in which a frequency of the carrier wave is modulated by the test signal, as a test signal modulated wave. The modulated wave generation unit <NUM> may generate an amplitude modulation (AM) modulated wave in which an amplitude of the carrier wave is modulated by the test signal, as a test signal modulated wave. The modulated wave generation unit <NUM> may generate a phase modulation (PM) modulated wave in which a phase of the carrier wave is modulated by the test signal, as a test signal modulated wave.

The test signal extraction unit <NUM> extracts the received test signal corresponding to the test signal from the signal propagated in the test signal receiving wire <NUM>. For example, the test signal extraction unit <NUM> extracts a test signal received wave corresponding to the test signal modulated wave from the signal propagated in the test signal receiving wire <NUM>, and extracts the received test signal from the test signal received wave.

For example, the test signal extraction unit <NUM> has a modulated wave extraction unit <NUM> and a demodulation unit <NUM> as functional blocks. The modulated wave extraction unit <NUM> extracts the test signal received wave corresponding to the test signal modulated wave from the signal propagated in the test signal receiving wire <NUM>. For example, the modulated wave extraction unit <NUM> extracts the test signal received wave by a bandpass filter corresponding to a frequency band of the test signal modulated wave. The demodulation unit <NUM> applies demodulation processing corresponding to the modulation processing for generating the test signal modulated wave to the test signal received wave to extract the received test signal.

The deterioration detection unit <NUM> detects the deterioration of the cable <NUM> based on the test signal and the received test signal. For example, the deterioration detection unit <NUM> detects the deterioration of the cable <NUM> based on a fluctuation in the difference between intensity (e.g., amplitude) of the test signal and intensity (e.g., amplitude) of the received test signal.

The deterioration detection unit <NUM> detects the deterioration of the cable <NUM> when the amount of fluctuation in the difference between the intensity (e.g., amplitude) of the test signal and the intensity (e.g., amplitude) of the received test signal exceeds a predetermined deterioration detection level. When the amount of fluctuation does not reach the deterioration detection level, the deterioration detection unit <NUM> does not detect deterioration of the cable <NUM> (detects no deterioration in the cable <NUM>).

The test signal output unit <NUM> outputs a test signal modulated wave to the test signal transmitting wire <NUM>, in which the test signal is superimposed on a carrier wave having a frequency different from a frequency of the signals transmitted by the one or more signal wires <NUM>. For example, the carrier wave generation unit <NUM> generates the carrier wave having the frequency different from the frequency of the signal transmitted by each of the plurality of signal wires <NUM>.

In this case, the magnitude of the frequency of the carrier wave depends on a diameter of the cable and the frequency of the signal transmitted by each of the plurality of signal wires <NUM>. Thus, the cable deterioration diagnosis device <NUM> may be configured so that the frequency of the carrier wave can be changed. For example, the main body <NUM> further has a frequency setting unit <NUM> as a functional block. The frequency setting unit <NUM> sets the frequency of the carrier wave based on an operation input by an operator (e.g., an input to an input device <NUM> described later). The carrier wave generation unit <NUM> generates a carrier wave with the frequency set by the frequency setting unit <NUM>. According to this configuration, the frequency of the carrier wave can be changed by the operation input.

To electrically connect the test signal transmitting wire <NUM> and the test signal receiving wire <NUM>, the main body <NUM> further has a connector <NUM>. The connector <NUM> has a conductive test signal transmitting terminal <NUM> and a conductive test signal receiving terminal <NUM>. The test signal transmitting terminal <NUM> is electrically connected to the test signal transmitting wire <NUM>, and the test signal receiving terminal <NUM> is electrically connected to the test signal receiving wire <NUM>. The modulated wave generation unit <NUM> outputs the test signal modulated wave to the test signal transmitting terminal <NUM>, and the modulated wave extraction unit <NUM> acquires the signal propagated in the test signal receiving wire <NUM> from the test signal receiving terminal <NUM>.

The adapter <NUM> connects the one or more signal wires <NUM> to the first device <NUM> and connects the test signal transmitting wire <NUM> and the test signal receiving wire <NUM> to the main body <NUM>. The adapter <NUM> has a first connector <NUM>, a main cable <NUM>, a second connector <NUM>, a branch cable <NUM>, and a third connector <NUM>.

The first connector <NUM> is connected to the connector <NUM>. The first connector <NUM> has a plurality of conductive terminals <NUM>. The plurality of terminals <NUM> each come into contact with the plurality of terminals <NUM> of the connector <NUM>. The plurality of terminals <NUM> includes one or more signal terminals <NUM> that each come into contact with the one or more signal terminals <NUM>, a test signal transmitting terminal <NUM> that comes into contact with the test signal transmitting terminal <NUM>, and a test signal receiving terminal <NUM> that comes into contact with the test signal receiving terminal <NUM>.

The main cable <NUM> has a first end <NUM> connected to the first device <NUM> and a second end <NUM> connected to the cable <NUM>. The main cable <NUM> has one or more signal wires <NUM>, a shield wire <NUM>, and a cable sheath <NUM>. Each of the one or more signal wires <NUM>, the shield wire <NUM>, and the cable sheath <NUM> is covered with an insulating individual sheath and is insulated from other electrical wires. The shield wire <NUM> is a net-like conductive member woven so as to cover the one or more signal wires <NUM>. The cable sheath <NUM> is an insulating tube formed so as to cover the shield wire <NUM>.

The second end <NUM> is connected to the first connector <NUM>. In the first connector <NUM>, the one or more signal wires <NUM> are connected to the one or more signal terminals <NUM>, respectively. The second connector <NUM> is provided at the first end <NUM>. The second connector <NUM> has one or more conductive signal terminals <NUM>. In the second connector <NUM>, the one or more signal wires <NUM> are connected to the one or more signal terminals <NUM>, respectively. The second connector <NUM> is connected to the first device <NUM>. Each of the one or more signal terminals <NUM> is electrically connected to a control circuit of the first device <NUM>. In this way, the one or more signal wires <NUM> are connected to the first device <NUM> via the one or more signal wires <NUM> of the main cable <NUM>.

The branch cable <NUM> has a first end <NUM> connected to the main body <NUM> and a second end <NUM> connected to the cable <NUM>. The branch cable <NUM> has a test signal transmitting wire <NUM>, a test signal receiving wire <NUM>, a shield wire <NUM>, and a cable sheath <NUM>. The test signal transmitting wire <NUM> and the test signal receiving wire <NUM> are each covered with insulating individual sheaths and are insulated from each other. The shield wire <NUM> is a net-like conductive member woven so as to cover the test signal transmitting wire <NUM> and the test signal receiving wire <NUM>. The cable sheath <NUM> is an insulating tube formed so as to cover the shield wire <NUM>. The second end <NUM> is connected to the first connector <NUM>. In the first connector <NUM>, the test signal transmitting wire <NUM> is connected to the test signal transmitting terminal <NUM>, and the test signal receiving wire <NUM> is connected to the test signal receiving terminal <NUM>.

The third connector <NUM> is provided at the first end <NUM>. The third connector <NUM> has a conductive test signal transmitting terminal <NUM> and a conductive test signal receiving terminal <NUM>. In the third connector <NUM>, the test signal transmitting wire <NUM> is connected to the test signal transmitting terminal <NUM>, and the test signal receiving wire <NUM> is connected to the test signal receiving terminal <NUM>. The third connector <NUM> is connected to the connector <NUM> of the main body <NUM>. The test signal transmitting terminal <NUM> comes into contact with the test signal transmitting terminal <NUM>, and the test signal receiving terminal <NUM> comes into contact with the test signal receiving terminal <NUM>. Thus, the test signal transmitting wire <NUM> and the test signal receiving wire <NUM> are connected to the main body <NUM> via the test signal transmitting wire <NUM> and the test signal receiving wire <NUM> of the branch cable <NUM>.

The cable deterioration diagnosis device <NUM> may be configured to calculate an estimated value of a residual life representing a length of a period of time until the deterioration level of the cable <NUM> exceeds an acceptable level, based on a frequency at which the amount of fluctuation exceeds the deterioration detection level. The term "frequency" is, for example, the number of occurrences per unit time.

For example, as illustrated in <FIG>, the main body <NUM> further has a data accumulation unit <NUM>, a database <NUM>, a model holding unit <NUM>, and a residual life estimation unit <NUM> as functional blocks. Each time the amount of fluctuation exceeds the deterioration detection level, the data accumulation unit <NUM> accumulates, in the database <NUM>, a fluctuation record in which a value of the amount of fluctuation is associated with a time. The model holding unit <NUM> stores a life prediction model. The life prediction model outputs the estimated value of the residual life in response to the input of the data including the frequency.

<FIG> is a graph illustrating the life prediction model. In <FIG>, the horizontal axis represents the frequency, and the vertical axis represents the estimated value of the residual life. The life prediction model <NUM>, which is indicated by a solid line in <FIG>, is defined by, for example, a single variable function or the like so as to output the estimated value of the residual life in response to the input of the frequency.

Returning to <FIG>, the residual life estimation unit <NUM> calculates the estimated value of the residual life based on the frequency at which the amount of fluctuation exceeds the deterioration detection level. For example, the residual life estimation unit <NUM> calculates the frequency at which the amount of fluctuation exceeds the deterioration detection level based on the fluctuation records accumulated in the database <NUM>. The residual life estimation unit <NUM> inputs the calculated frequency to the life prediction model <NUM> to calculate the estimated value of the residual life.

The cable deterioration diagnosis device <NUM> may be configured to calculate the estimated value of the residual life based on the amount of fluctuation. For example, the life prediction model <NUM> stored in the model holding unit <NUM> may be configured to output the estimated value of the residual life in response to an input of data including the amount of fluctuation. For example, the life prediction model <NUM> may be defined by, for example, a single variable function so as to output the estimated value of the residual life in response to an input of the amount of fluctuation. The residual life estimation unit <NUM> inputs the amount of fluctuation included in the latest fluctuation record into the life prediction model <NUM> to calculate the estimated value of the residual life.

The cable deterioration diagnosis device <NUM> may be configured to calculate the estimated value of the residual life based on the amount of fluctuation and the frequency. For example, the life prediction model <NUM> stored in the model holding unit <NUM> may be configured to output the estimated value of the residual life in response to an input of data including the amount of fluctuation and the frequency. For example, the life prediction model <NUM> may be defined by, for example, a two-variable function so as to output the estimated value of the residual life in response to inputs of the amount of fluctuation and the frequency. The residual life estimation unit <NUM> calculates the frequency at which the amount of fluctuation exceeds the deterioration detection level based on the fluctuation records accumulated in the database <NUM>. The residual life estimation unit <NUM> inputs the calculated frequency and the amount of fluctuation included in the latest fluctuation record into the life prediction model <NUM> to calculate the estimated value of the residual life.

The cable deterioration diagnosis device <NUM> may be configured to calculate the estimated value of the residual life based on frequency distribution data representing the frequency of the amount of fluctuation for each of a plurality of bands. For example, the main body <NUM> further has a distribution data generation unit <NUM> as a functional block. The distribution data generation unit <NUM> generates frequency distribution data representing the frequency for each of the plurality of bands based on the fluctuation records accumulated in the database <NUM>.

For example, the distribution data generation unit <NUM> generates frequency distribution data (e.g., a frequency distribution table) that represents the frequency for each of the plurality of bands obtained by dividing the magnitude of the amount of fluctuation by a plurality of boundary values arranged at equal distances. The life prediction model <NUM> stored in the model holding unit <NUM> may be configured to output the estimated value of the residual life in response to an input of the frequency distribution data. Examples of the life prediction model <NUM> include neural networks, self-organizing maps and the like constructed by machine learning. The residual life estimation unit <NUM> calculates the estimated value of the residual life based on the frequency distribution data generated by the distribution data generation unit <NUM> and the life prediction model <NUM>. For example, the residual life estimation unit <NUM> inputs the frequency distribution data generated by the distribution data generation unit <NUM> into the life prediction model <NUM> to calculate the estimated value of the residual life.

The cable deterioration diagnosis device <NUM> may be configured to calculate the estimated value of the residual life based on two or more frequency distribution data in time series. For example, the distribution data generation unit <NUM> repeatedly generates frequency distribution data each time a predetermined number of fluctuation records are added to the database <NUM>. The predetermined number may be one or two or more. The data accumulation unit <NUM> accumulates the frequency distribution data generated repeatedly by the distribution data generation unit <NUM> in the database <NUM> in time series. For example, the data accumulation unit <NUM> accumulates frequency distribution data in the database <NUM> in association with a time (e.g., the time of generation of the frequency distribution data).

The life prediction model <NUM> stored in the model holding unit <NUM> may be configured to output the estimated value of the residual life in response to inputs of two or more frequency distribution data in time series. The residual life estimation unit <NUM> calculates the estimated value of the residual life based on the two or more frequency distribution data in time series accumulated in the database <NUM> and the life prediction model <NUM>. For example, the residual life estimation unit <NUM> inputs the two or more frequency distribution data in time series accumulated in the database <NUM> into the life prediction model <NUM> to calculate the estimated value of the residual life. <FIG> is a graph illustrating two or more frequency distribution data input to the life prediction model <NUM>. In <FIG>, the horizontal axis represents the amount of fluctuation, and the vertical axis represents the elapsed time. A plurality of circles aligned in the horizontal row are one set of frequency distribution data. The size of each of the plurality of circles represents the frequency. The graph in <FIG> contains six sets of frequency distribution data in time series.

Returning to <FIG>, the cable deterioration diagnosis device <NUM> may be configured to notify that the estimated value of the residual life has reached a predetermined notification level. For example, the main body <NUM> further has a notification unit <NUM> as a functional block. The notification unit <NUM> displays a warning indication on a display device <NUM> or the like described later, for notifying that the estimated value of the residual life calculated by the residual life estimation unit <NUM> drops until the estimated value of the residual life reaches a predetermined notification level. For example, the notification unit <NUM> compares the estimated value of the residual life calculated by the residual life estimation unit <NUM> with the notification level, and displays the warning indication on the display device <NUM> or the like when the estimated value of the residual life is below the notification level.

The cable deterioration diagnosis device <NUM> may be configured to update the life prediction model <NUM> based on data accumulated in the database <NUM> when the deterioration level exceeds an acceptable level. For example, the main body <NUM> further has a life detection unit <NUM>, a teacher data generation unit <NUM>, and a model update unit <NUM> as functional blocks.

The life detection unit <NUM> detects that the deterioration level exceeds the acceptable level. Hereinafter, the deterioration level exceeding the acceptable level is referred to as an "end of life of the cable <NUM>". An example of the acceptable level is a level at which a communication failure due to the cable <NUM> is detected in the first device <NUM>. In this case, the life detection unit <NUM> detects the end of life of the cable <NUM> when a signal indicating the occurrence of communication failure due to the cable <NUM> is acquired from the first device <NUM>. The acceptable level may be a level at which the frequency at which the amount of fluctuation exceeds the deterioration detection level exceeds a predetermined upper limit value. In this case, the life detection unit <NUM> calculates the frequency based on the fluctuation records accumulated in the database <NUM>, and detects the end of life of the cable <NUM> when the frequency exceeds the upper limit value. The acceptable level may be a level at which the amount of fluctuation exceeds a predetermined upper limit value. In this case, the life detection unit <NUM> detects the end of life of the cable <NUM> when the amount of fluctuation included in the latest fluctuation record exceeds the upper limit value. The life detection unit <NUM> may detect the end of life of the cable <NUM> based on the input to the input device <NUM> described later.

When the deterioration level exceeds the acceptable level, the teacher data generation unit <NUM> generates teacher data representing a relationship between the two or more frequency distribution data and the estimated value of the residual life based on the data accumulated in the database <NUM>. For example, the teacher data generation unit <NUM> generates the teacher data based on the data accumulated in the database <NUM> when the end of life of the cable <NUM> is detected by the life detection unit <NUM>. Hereinafter, the two or more frequency distribution data required for generating the teacher data are referred to as map data.

When the number of frequency distribution data accumulated in the database <NUM> is greater than the number of frequency distribution data in the map data, the teacher data generation unit <NUM> may generate two or more teacher data. When the number of frequency distribution data accumulated in the database <NUM> is greater than the number of frequency distribution data in the map data, the database <NUM> will contain two or more map data, including the latest frequency distribution data and the oldest frequency distribution data separately. The teacher data generation unit <NUM> generates a period up to the detection timing of the end of life of the cable <NUM> for each of the two or more map data by the generation timing of the latest frequency distribution data. Hereinafter, the period generated here is referred to as a "measured life period". The teacher data generation unit <NUM> generates two or more teacher data by mapping the measured life period to each of the two or more map data.

The data accumulation unit <NUM> accumulates the teacher data generated by the teacher data generation unit <NUM> in the database <NUM>. The model update unit <NUM> updates the life prediction model <NUM> by machine learning based on the teacher data accumulated in the database <NUM>, and stores the updated life prediction model <NUM> in the model holding unit <NUM>.

<FIG> is a block diagram illustrating a hardware configuration of the main body <NUM>. As illustrated in <FIG>, the main body <NUM> includes a circuit <NUM> and the connector <NUM>. The circuit <NUM> has one or more processors <NUM>, a memory <NUM>, a storage <NUM>, a carrier wave generation circuit <NUM>, a baseband generation circuit <NUM>, a modulation circuit <NUM>, an AD conversion circuit <NUM>, the display device <NUM>, and the input device <NUM>. The storage <NUM> stores a program for causing a device to execute a cable deterioration diagnosis method that includes outputting a wave-like test signal to the test signal transmitting wire <NUM>, extracting a received test signal corresponding to the test signal from the signal propagated in the test signal receiving wire <NUM>, and detecting deterioration of the cable <NUM> based on the test signal and the received test signal. For example, the storage <NUM> stores a program for configuring each of the above functional blocks in the cable deterioration diagnosis device <NUM>.

The storage <NUM> includes a storage medium that stores the program. Examples of the storage medium include stationary media such as a hard disk, a non-volatile memory and the like, and portable media such as a USB memory, an optical disk, a magnetic disk and the like.

The memory <NUM> temporarily stores a program loaded from the storage <NUM>. The one or more processors <NUM> configure each of the above functional blocks in the main body <NUM> by executing the program loaded into the memory <NUM>. The data generated by the one or more processors <NUM> in the process of executing the program is stored in the memory <NUM> as appropriate.

The carrier wave generation circuit <NUM> generates the carrier wave at a frequency determined by the one or more processors <NUM>. The baseband generation circuit <NUM> generates the test signal defined by the one or more processors <NUM>. The modulation circuit <NUM> modulates the carrier wave generated by the carrier wave generation circuit <NUM> with the test signal generated by the baseband generation circuit <NUM> to generate the test signal modulated wave, and outputs the generated test signal modulated wave via the test signal transmitting terminal <NUM> of the connector <NUM> to the test signal transmitting wire <NUM>.

The AD conversion circuit <NUM> acquires an analog signal from the test signal receiving wire <NUM> via the test signal receiving terminal <NUM> of the connector <NUM> and converts the acquired analog signal into a digital signal. By applying digital signal processing to the digital signal generated by the AD conversion circuit <NUM> with this conversion, the test signal received wave is extracted and the received test signal is extracted.

The display device <NUM> displays an image in response to a request from the one or more processors <NUM>. Examples of the display device <NUM> include a liquid crystal monitor and the like. The input device <NUM> acquires an operation input by the operator and notifies one or more processors <NUM> of the content of the operation input. Examples of the input device <NUM> include a keyboard, a mouse and the like. The input device <NUM> may be integrated into the display device <NUM> as a so-called touch panel.

The hardware configuration described above is merely an example, and can be modified as appropriate. For example, at least any one of the functional blocks may be configured by dedicated circuitry such as an application specific integrated circuit (ASIC) instead of the general-purpose processor <NUM>.

Next, as an example of a cable deterioration diagnosis method, a cable deterioration diagnosis procedure executed by the cable deterioration diagnosis device <NUM> will be illustrated. The procedure includes outputting a wave-like test signal to the test signal transmitting wire <NUM>, extracting a received test signal corresponding to the test signal from the signal propagated in the test signal receiving wire <NUM>, and detecting deterioration of the cable <NUM> based on the test signal and the received test signal.

For example, as illustrated in <FIG>, the cable deterioration diagnosis device <NUM> first executes steps S01 and S02. In step S01, the frequency setting unit <NUM> sets the frequency of the carrier wave based on the operation input by the operator.

In step S02, the test signal output unit <NUM> starts outputting the test signal. For example, the test signal generation unit <NUM> starts generating the test signal, the carrier wave generation unit <NUM> starts generating the carrier wave, and the modulated wave generation unit <NUM> starts generating the test signal modulated wave and outputting the generated test signal modulated wave to the test signal transmitting wire <NUM>.

Subsequently, the cable deterioration diagnosis device <NUM> executes steps S03 and S04. In step S03, the modulated wave extraction unit <NUM> extracts the test signal received wave corresponding to the test signal modulated wave from the signal propagated in the test signal receiving wire <NUM>. In step S04, the demodulation unit <NUM> applies demodulation processing corresponding to modulation processing for generating the test signal modulated wave to the test signal received wave to extract the received test signal.

Subsequently, the cable deterioration diagnosis device <NUM> executes steps S05 and <NUM>. In step S05, the deterioration detection unit <NUM> calculates the amount of fluctuation in the difference between the intensity of the test signal and the intensity of the received test signal. In step S06, the deterioration detection unit <NUM> checks whether the amount of fluctuation exceeds the deterioration detection level.

In step S06, when the amount of fluctuation is determined not to reach the deterioration detection level, the cable deterioration diagnosis device <NUM> returns the processing to step S03. In step S06, when the amount of fluctuation is determined to exceed the deterioration detection level, the cable deterioration diagnosis device <NUM> executes steps S07 and S08. In step S07, the data accumulation unit <NUM> accumulates, in the database <NUM>, a fluctuation record in which a value of the amount of fluctuation is associated with a time. In step S08, the distribution data generation unit <NUM> generates the frequency distribution data representing the frequency for each of the plurality of bands based on the fluctuation records accumulated in the database <NUM>. The generated frequency distribution data is accumulated in the database <NUM> by the data accumulation unit <NUM>.

Subsequently, the cable deterioration diagnosis device <NUM> executes steps S09 and S11. In step S09, the residual life estimation unit <NUM> inputs the frequency distribution data into the life prediction model <NUM> to calculate the estimated value of the residual life. The residual life estimation unit <NUM> may input two or more frequency distribution data in time series into the life prediction model <NUM> to calculate the estimated value of the residual life. In step S11, the notification unit <NUM> checks whether the estimated value of the residual life is below the notification level.

In step S11, when the estimated value of the residual life is determined to be above the notification level, the cable deterioration diagnosis device <NUM> returns the processing to step S03. In step S <NUM>, when the estimated value of the residual life is determined to be below the notification level, the cable deterioration diagnosis device <NUM> executes step S12. In step S12, the notification unit <NUM> displays the warning indication on the display device <NUM>. The cable deterioration diagnosis device <NUM> then returns the processing to step S03. The cable deterioration diagnosis device <NUM> repeats steps S03 to S12.

As described above, the cable deterioration diagnosis device <NUM> may be configured to update the life prediction model <NUM> based on the data accumulated in the database <NUM> when the deterioration level exceeds the acceptable level. <FIG> is a flowchart illustrating a procedure for updating the life prediction model <NUM>. This procedure is executed simultaneously with the cable deterioration diagnosis procedure described above.

As illustrated in <FIG>, the cable deterioration diagnosis device <NUM> executes steps S21 and S22. In step S21, the life detection unit <NUM> waits for the deterioration level of the cable <NUM> to exceed the acceptable level. In step S22, the teacher data generation unit <NUM> generates the teacher data representing the relationship between the two or more frequency distribution data and the estimated value of the residual life. The generated teacher data is accumulated in the database <NUM> by the data accumulation unit <NUM>.

Subsequently, the cable deterioration diagnosis device <NUM> executes step S23. In step S23, the model update unit <NUM> checks whether the number of untrained teacher data accumulated in the database <NUM> exceeds a predetermined update threshold value. The term "untrained teacher data" means teacher data that has not yet been used for updating the life prediction model <NUM>.

In step S23, when the number of untrained teacher data is determined not to reach the update threshold value, the cable deterioration diagnosis device <NUM> returns the processing to step S21. In step S23, the number of untrained teacher data is determined to exceed the update threshold value, the cable deterioration diagnosis device <NUM> executes step S24. In step S24, the model update unit <NUM> updates the life prediction model <NUM> by machine learning based on the teacher data accumulated in the database <NUM>, and stores the updated life prediction model <NUM> in the model holding unit <NUM>. The cable deterioration diagnosis device <NUM> then returns the processing to step S21. The cable deterioration diagnosis device <NUM> repeats the above processing.

As described above, the cable deterioration diagnosis device <NUM> is a device for diagnosing the deterioration of the cable <NUM> having the plurality of electrical wires including the one or more signal wires <NUM> that transmit signals between the first device <NUM> and the second device <NUM>, and includes the test signal output unit <NUM> that outputs the wave-like test signal to the test signal transmitting wire <NUM> independent of the one or more signal wires <NUM> among the plurality of electrical wires, the test signal extraction unit <NUM> that extracts the received test signal corresponding to the test signal from the signal propagated in the test signal receiving wire <NUM> independent of the one or more signal wires <NUM> and the test signal transmitting wire <NUM> among the plurality of electrical wires, and the deterioration detection unit <NUM> that detects the deterioration of the cable <NUM> based on the test signal and the received test signal.

According to the method of adding the high-frequency pulse to the signal wires <NUM> themselves, which are the targets of deterioration detection, it is necessary to inject the high-frequency pulse into each of the plurality of signal wires <NUM> in order to detect the deterioration in the plurality of signal wires <NUM>. In contrast, according to the cable deterioration diagnosis device <NUM>, the deterioration of the cable <NUM> can be detected based on the test signal output to the single test signal transmitting wire <NUM> and the received test signal propagated in the single test signal receiving wire <NUM>, regardless of the number of signal wires <NUM>. Therefore, it is effective in detecting the deterioration of the cable <NUM> with a simpler configuration.

The deterioration detection unit <NUM> may detect the deterioration of the cable <NUM> when the amount of fluctuation in the difference between the intensity of the test signal and the intensity of the received test signal exceeds the predetermined deterioration detection level. In this case, the deterioration of the cable <NUM> can be detected with high reliability by appropriately setting the deterioration detection level.

The test signal output unit <NUM> may output the test signal modulated wave, in which the test signal is superimposed on the carrier wave, to the test signal transmitting wire <NUM>, and the test signal extraction unit <NUM> may extract the test signal received wave corresponding to the test signal modulated wave from the signal propagated in the test signal receiving wire <NUM>, and may extract the received test signal from the test signal received wave. In this case, the received test signal can be extracted with higher reliability by superimposing the test signal on the carrier wave.

The test signal output unit <NUM> outputs the test signal modulated wave to the test signal transmitting wire <NUM> in which the test signal is superimposed on the carrier wave having the frequency different from the frequency of the signals transmitted by the one or more signal wires <NUM>. In this case, the received test signal can be extracted with higher reliability by appropriately setting the frequency of the carrier wave.

The cable deterioration diagnosis device <NUM> may further include the residual life estimation unit <NUM> that calculates the estimated value of the residual life representing the length of the period of time until the deterioration level of the cable <NUM> exceeds the acceptable level, based on the frequency at which the amount of fluctuation exceeds the deterioration detection level. There is a correlation between the frequency and the estimated value of the residual life. Therefore, the estimated value of the residual life can be calculated with high reliability based on the frequency.

The cable deterioration diagnosis device <NUM> may further include the residual life estimation unit <NUM> that calculates the estimated value of the residual life representing the length of the period of time until the deterioration level of the cable <NUM> exceeds the acceptable level, based on the amount of fluctuation. There is a correlation between the amount of fluctuation and the estimated value of the residual life. Therefore, the estimated value of the residual life can be calculated with high reliability based on the amount of fluctuation.

The cable deterioration diagnosis device <NUM> may further include the distribution data generation unit <NUM> that generates the frequency distribution data representing the frequency of the amount of fluctuation for each of the plurality of bands, and the residual life estimation unit <NUM> that calculates the estimated value of the residual life representing the length of the period of time until the deterioration level of the cable <NUM> exceeds the acceptable level based on the frequency distribution data. Based on the frequency of the amount of fluctuation for each band, the estimated value of the residual life can be calculated with higher reliability.

The residual life estimation unit <NUM> may calculate the estimated value of the residual life based on the two or more frequency distribution data in time series. Further based on the temporal change of the frequency distribution data, the estimated value of the residual life can be calculated with higher reliability.

The residual life estimation unit <NUM> may calculate the estimated value of the residual life based on the two or more frequency distribution data in time series and the life prediction model that outputs the estimated value of the residual life in response to the two or more frequency distribution data inputs in time series. Further based on the temporal change of the frequency distribution data, the estimated value of the residual life can be calculated with higher reliability.

The cable deterioration diagnosis device <NUM> may further include the data accumulation unit <NUM> that accumulates the frequency distribution data in the database <NUM> in time series, the teacher data generation unit <NUM> that generates the teacher data representing the relationship between the two or more frequency distribution data and the estimated value of the residual life based on data accumulated in the database <NUM> when the deterioration level exceeds the acceptable level, and the model update unit <NUM> that updates the life prediction model by machine learning based on the teacher data. In this case, by updating the life estimation model based on the measured value of the residual life, the reliability of the estimated value of the residual life calculated based on the life prediction model can be further improved.

The cable deterioration diagnosis device <NUM> may further include the notification unit <NUM> that notifies that the estimated value of the residual life has reached the predetermined notification level. In this case, the deterioration of the cable <NUM> can be notified at a more appropriate timing.

The cable deterioration diagnosis device <NUM> may include the main body <NUM> having the test signal output unit <NUM>, the test signal extraction unit <NUM>, and the deterioration detection unit <NUM>, and the adapter <NUM> that connects the signal wire <NUM> to the first device <NUM> and connects the test signal transmitting wire <NUM> and the test signal receiving wire <NUM> to the main body <NUM>. In this case, the cable deterioration diagnosis device <NUM> can be easily inserted between the first device <NUM> and the cable <NUM>.

The machine system <NUM> includes the cable deterioration diagnosis device <NUM>, the first device <NUM>, the second device <NUM>, and the cable <NUM>, and the second device <NUM> has the movable unit <NUM> that operates while bending the cable <NUM>. Since the cable deterioration diagnosis device <NUM> is applied to the machine system <NUM> in which the cable <NUM> is bent, it is more beneficial to be able to detect the deterioration of the cable <NUM> with a simpler configuration. Note that, according to the cable deterioration diagnosis device <NUM>, the cable deterioration caused by, for example, an object external to the machine system <NUM> coming into contact with the cable <NUM> can also be detected. Therefore, it is also applicable to a system that does not include the movable unit <NUM> that operates while bending the cable <NUM>.

The second device <NUM> may be a robot having the plurality of joints <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> as the movable unit <NUM>. Since the cable deterioration diagnosis device <NUM> is applied to the robot in which the cable <NUM> is bent more frequently, it is more beneficial to be able to detect the deterioration of the cable <NUM> with a simpler configuration.

Claim 1:
A cable deterioration diagnosis device (<NUM>) configured to diagnose deterioration of a cable (<NUM>) having a plurality of electrical wires (<NUM>) including one or more signal wires (<NUM>) configured to transmit signals between a first device (<NUM>) and a second device (<NUM>), the cable deterioration diagnosis device (<NUM>) comprising:
a test signal output unit (<NUM>) configured to output a test signal having a wavelike shape to a test signal transmitting wire (<NUM>), the test signal transmitting wire (<NUM>) being independent of the one or more signal wires (<NUM>) among the plurality of electrical wires (<NUM>);
a test signal extraction unit (<NUM>) configured to extract a received test signal corresponding to the test signal from a signal propagated in a test signal receiving wire (<NUM>), the test signal receiving wire (<NUM>) being independent of the one or more signal wires (<NUM>) and the test signal transmitting wire (<NUM>) among the plurality of electrical wires (<NUM>); and
a deterioration detection unit (<NUM>) configured to detect deterioration of the cable (<NUM>) based on the test signal and the received test signal
wherein the deterioration detection unit (<NUM>) detects the deterioration of the cable (<NUM>) when an amount of fluctuation in a difference between intensity of the test signal and intensity of the received test signal exceeds a predetermined deterioration detection level,
characterized in that
the test signal output unit (<NUM>) outputs a test signal modulated wave, in which the test signal is superimposed on a carrier wave, to the test signal transmitting wire (<NUM>), and
the test signal extraction unit (<NUM>) extracts a test signal received wave corresponding to the test signal modulated wave from the signal propagated in the test signal receiving wire (<NUM>), and extracts the received test signal from the test signal received wave.