Operational status determining apparatus, method, and recording medium

Abstract

To provide a threshold value for a current flowing through a power cable to determine whether or not electrical equipment connected to the power cable is operating.SOLUTION: An operational status determining apparatus 1 includes a current measuring section 11, and an on / off determining section 13. The current measuring section measures a current through a power cable 4 connected to an electrical equipment 2. The on / off determining section determines that the electrical equipment 2 is powered on when the current is higher than a threshold value Ath, while determines that the electrical equipment 2 is powered off when the current is lower than the threshold value Ath. The threshold value Ath is equal to or higher than a current upper limit below which the electrical equipment 2 is definitely powered off, and equal to or lower than a current lower limit above which the electrical equipment 2 is definitely powered on.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to determining the operating status of an electrical device. [Background technology]

[0002] Conventionally, there has been known a technique for determining the operating status of an electrical appliance connected to a power cable by detecting an AC current flowing through the power cable (see, for example,

[0032] to

[0035] of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-109634 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the above-mentioned conventional technology, it is unclear what level of AC current flowing through the power cable is required to determine whether the electrical device connected to the power cable is operating. In other words, it is unclear what the threshold value of the AC current flowing through the power cable is for determining whether the electrical device is operating.

[0005] Therefore, an object of the present invention is to provide a threshold value of a current flowing through a power cable for determining whether an electric device connected to the power cable is operating. [Means for solving the problem]

[0006] The operating status determination device of the present invention comprises a current measuring unit that measures the current in a power cable connected to an electrical device, and an on / off determination unit that determines that the power supply of the electrical device is on when the current exceeds a threshold value, and determines that the power supply of the electrical device is off when the current is less than the threshold value, wherein the threshold value is configured to be equal to or greater than an upper limit of current at which it is certain that the power supply of the electrical device is off, and equal to or less than a lower limit of current at which it is certain that the power supply of the electrical device is on.

[0007] According to the operating state determination device configured as described above, the current measurement unit measures the current of the power cable connected to the electric device. The on / off determination unit determines that the power supply of the electric device is on when the current exceeds a threshold value, and determines that the power supply of the electric device is off when the current is less than the threshold value. The threshold value is equal to or greater than an upper limit of the current at which it is certain that the power supply of the electric device is off, and is equal to or less than a lower limit of the current at which it is certain that the power supply of the electric device is on.

[0008] In the operating state determination device according to the present invention, the current measurement unit may be a non-contact sensor that does not come into contact with the power cable.

[0009] In addition, the operating state determination device of the present invention may include a threshold derivation unit that derives the threshold value, an on current derivation unit that derives the value of an on current, which is the current when the power supply of the electrical equipment is on, and an off current derivation unit that derives the value of an off current, which is the current when the power supply of the electrical equipment is off, and the threshold derivation unit may derive the threshold value by multiplying the value obtained by subtracting the value of the off current from the value of the on current by a predetermined coefficient.

[0010] In the operating state determining device according to the present invention, the on-current deriving unit may derive the value of the on-current as an average value of the measured values ​​of the current.

[0011] In addition, in the operating state determination device of the present invention, the on-current derivation unit may be configured to set the average value of the current measurements as a new on-current value when the average value of the current measurements exceeds the on-current value + (maximum value of the current measurements within a specified period - minimum value of the current measurements within a specified period) / 2.

[0012] In the operating state determining device according to the present invention, the off-current deriving unit may derive the value of the off-current as an average value of the measured values ​​of the current.

[0013] In addition, in the operating state determination device of the present invention, the off-current derivation unit may be configured to set the average value of the current measurements as a new off-current value when the average value of the current measurements becomes less than the off-current value-(maximum value of the current measurements within a specified period-minimum value of the current measurements within a specified period) / 2.

[0014] In addition, in the operating state determination device according to the present invention, the off-current derivation unit may derive the value of the off-current as a mode of the measured current values ​​during a period in which the power supply of the electrical equipment is off.

[0015] In addition, the operating state determination device of the present invention may include an on-current derivation instruction unit that instructs the on-current derivation unit to derive the value of the on-current, and an off-current derivation instruction unit that instructs the off-current derivation unit to derive the value of the off-current, and the on-current derivation instruction unit and the off-current derivation instruction unit may be separate.

[0016] The operating state determination device according to the present invention may further include an on / off current derivation instruction unit that instructs the on current derivation unit and the off current derivation unit to perform derivation, and when the on / off current derivation instruction unit receives a first operation, it may instruct the on current derivation unit to perform derivation, and when it receives a second operation, it may instruct the off current derivation unit to perform derivation.

[0017] The operating state determination device according to the present invention is an operating state determination device including a notification unit that notifies that the on / off current derivation instruction unit has received the first operation and that the second operation has been received.

[0018] The present invention is an operating state determination method for determining the operating state of an electrical device using a current measuring unit that measures the current in a power cable connected to the electrical device, and includes an on / off determination process for determining that the power supply of the electrical device is on if the current exceeds a threshold value, and determining that the power supply of the electrical device is off if the current is less than the threshold value, wherein the threshold value is equal to or greater than an upper limit of current at which it is certain that the power supply of the electrical device is off, and equal to or less than a lower limit of current at which it is certain that the power supply of the electrical device is on.

[0019] The present invention is a computer-readable recording medium having recorded thereon a program for causing a computer to execute an operating state determination process for determining the operating state of an electrical appliance using a current measuring unit that measures the current in a power cable connected to the electrical appliance, the operating state determination process including an on / off determination step for determining that the power supply of the electrical appliance is on if the current exceeds a threshold value, and for determining that the power supply of the electrical appliance is off if the current is less than the threshold value, the threshold value being equal to or greater than an upper limit of current at which it is certain that the power supply of the electrical appliance is off, and equal to or less than a lower limit of current at which it is certain that the power supply of the electrical appliance is on. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram for explaining an environment in which a sensor tag (operating state determination device) 1 according to an embodiment of the present invention is used. [Diagram 2] FIG. 1 is a functional block diagram showing a configuration of a sensor tag (operating state determining device) 1 according to a first embodiment. [Diagram 3] FIG. 13 is a diagram for explaining a threshold value Ath. [Figure 4]FIG. 1 is a functional block diagram showing a configuration of a sensor tag (operating state determining device) 1 according to a second embodiment. [Diagram 5] FIG. 11 is a functional block diagram showing a configuration of an on-current derivation unit 14 according to a third embodiment. [Figure 6] FIG. 11 is a functional block diagram showing a configuration of an off-current derivation section 16 according to a third embodiment. [Figure 7] FIG. 13 is a functional block diagram showing a configuration of a sensor tag (operating state determining device) 1 according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a diagram for explaining an environment in which a sensor tag (operating state determining device) 1 according to an embodiment of the present invention is used.

[0023] The electric device 2 is, for example, a home appliance such as a display or a small electric fan. A power cable 4 is connected to the electric device 2. The electric device 2 is connected to a power source (not shown) via the power cable 4. When the electric device 2 is turned on, an alternating current flows through the power cable 4.

[0024] A sensor tag (operating state determination device) 1 is connected to a battery 6 and receives power from the battery 6. The sensor tag 1 receives electromagnetic waves generated by a current flowing through a power cable 4 and determines the operating state (on or off) of an electric device 2.

[0025] The environment in which the sensor tag 1 is used is common to the following embodiments.

[0026] First embodiment Fig. 2 is a functional block diagram showing the configuration of the sensor tag (operating state determination device) 1 according to the first embodiment. Fig. 3 is a diagram for explaining the threshold value Ath.

[0027] The sensor tag (operating state determining device) 1 according to the first embodiment includes a current measuring unit 11, a threshold recording unit 12, an on / off determining unit 13, an on current derivation unit 14, an off current derivation unit 16, and a threshold derivation unit 18.

[0028] The current measuring unit 11 measures the current of the power cable 4 connected to the electric device 2. The current measuring unit 11 is a non-contact sensor that does not come into contact with the power cable 4.

[0029] The threshold recording unit 12 records the threshold Ath.

[0030] The on / off determination unit 13 determines that the power supply of the electric device 2 is on when the current exceeds the threshold Ath, and determines that the power supply of the electric device 2 is off when the current is less than the threshold Ath. Note that, when the current is equal to the threshold Ath, the on / off determination unit 13 determines that the power supply of the electric device 2 is off (or may determine that the power supply is on).

[0031] The threshold Ath is equal to or greater than the upper limit (e.g., 0.05 Amax) of the current at which the power supply of the electric device 2 is reliably turned off, and equal to or less than the lower limit (e.g., 0.65 Amax) of the current at which the power supply of the electric device 2 is reliably turned on. This will be described later with reference to FIG. 3.

[0032] The on-current derivation unit 14 derives the value of the on-current, which is the current when the power supply of the electric device 2 is on. The off-current derivation unit 16 derives the value of the off-current, which is the current when the power supply of the electric device 2 is off. The threshold derivation unit 18 derives the threshold Ath. The threshold derivation unit 18 derives the threshold Ath by multiplying the value obtained by subtracting the value of the off-current (e.g., 0) from the value of the on-current (e.g., Amax) by a predetermined coefficient (e.g., a value not less than 0.05 and not more than 0.65) (see FIG. 3).

[0033] 3, it is assumed that the power supply of the electric device 2 is on from time 0 to t0 and is off after time t0. However, the vertical axis of Fig. 3 indicates the measurement result by the current measuring unit 11, and the horizontal axis of Fig. 3 indicates time.

[0034] Then, from time 0 to t0, the measurement result of current measurement unit 11 is the on-current. However, in Fig. 3, for convenience of explanation, it is assumed that the on-current is an ideal state in which it is constant at a predetermined value Amax. On the other hand, after time t0, the measurement result of current measurement unit 11 is the off-current. However, in Fig. 3, for convenience of explanation, it is assumed that the off-current is an ideal state in which it is constant at 0.

[0035] Incidentally, when the power supply of the electric device 2 is on, the circuitry within the electric device 2 consumes or does not consume current as necessary. This results in large fluctuations in the value of the on-current. Therefore, even if the measurement result of the current measurement unit 11 is significantly smaller than Amax, it is possible to be certain that the power supply of the electric device 2 is on. For example, if the measurement result of the current measurement unit 11 is 0.65Amax (=0.65×(Amax−0)) or more, it is possible to be certain that the power supply of the electric device 2 is on. This 0.65Amax is the lower limit of the current at which it is certain that the power supply of the electric device 2 is on. In addition, in FIG. 3, the region where it is certain that the power supply of the electric device 2 is on is illustrated as Ar-on.

[0036] On the other hand, when the power supply of the electric device 2 is off, the circuit in the electric device 2 is almost stopped and waits with minimum power until the power supply is turned on. This reduces fluctuations in the value of the off current. Therefore, even if the measurement result of the current measurement unit 11 is slightly higher than 0, it is possible to be certain that the power supply of the electric device 2 is off. For example, if the measurement result of the current measurement unit 11 is 0.05 Amax (= 0.05 × (Amax - 0)) or less, it is possible to be certain that the power supply of the electric device 2 is off. This 0.05 Amax is the upper limit of the current at which it is certain that the power supply of the electric device 2 is off. In addition, in FIG. 3, the region where it is certain that the power supply of the electric device 2 is off is illustrated as Ar-off.

[0037] Here, the threshold value Ath is equal to or greater than 0.05 Amax and equal to or less than 0.65 Amax. For example, the threshold value Ath is 0.5 Amax.

[0038] 3, the explanation has been given on the assumption that the on-current and the off-current are constant. However, in reality, the on-current and the off-current fluctuate. Therefore, the average value of the current measured by the current measuring unit 11 is set as the on-current or the off-current.

[0039] The on-current derivation section 14 derives the value of the on-current as the average value of the current measured by the current measurement section 11. The on-current derivation section 14 has an on-current derivation instruction section 14a and an on-current average derivation section 14b.

[0040] On-current derivation instruction unit 14a instructs on-current average derivation unit 14b of on-current derivation unit 14 to derive the on-current value. On-current average derivation unit 14b derives the average value of the current measured by current measurement unit 11 as the on-current, and provides it to threshold derivation unit 18.

[0041] The on-current derivation instruction unit 14a is, for example, a button that is pressed by a user. When the user confirms that the power supply of the electric device 2 is on and then presses this button, an instruction to derive the value of the on-current is issued.

[0042] Off-state current derivation section 16 derives the value of the off-state current as the average value of the current measured by current measurement section 11. Off-state current derivation section 16 has off-state current derivation instruction section 16a and off-state current average derivation section 16b.

[0043] Off-current derivation instruction unit 16a instructs off-current average derivation unit 16b of off-current derivation unit 16 to derive the value of the off-current. Off-current average derivation unit 16b derives the average value of the current measured by current measurement unit 11 as the off-current, and provides it to threshold derivation unit 18.

[0044] The off-current derivation instruction unit 16a is, for example, a button that is pressed by a user. When the user confirms that the power supply of the electric device 2 is off and then presses this button, an instruction to derive the value of the off-current is issued.

[0045] Moreover, the ON current derivation instruction section 14a and the OFF current derivation instruction section 14b are separate (for example, separate buttons).

[0046] Next, the operation of the first embodiment will be described.

[0047] First, the electric device 2 is powered on. After the user confirms that the electric device 2 is powered on, the user operates the on-current derivation instruction unit 14a (presses a button), which instructs the on-current average derivation unit 14b to derive an on-current value. The average value of the current measured by the current measurement unit 11 is derived as the on-current by the on-current average derivation unit 14b and provided to the threshold derivation unit 18.

[0048] Next, the power supply of the electric device 2 is turned off. Here, when the user confirms that the power supply of the electric device 2 is turned off and operates the off-current derivation instruction unit 16a (presses a button), an instruction is given to the off-current average derivation unit 16b to derive the value of the off-current. The average value of the current measured by the current measurement unit 11 is derived as the off-current by the off-current average derivation unit 16b and provided to the threshold derivation unit 18.

[0049] The threshold derivation unit 18 derives the threshold Ath by multiplying the value obtained by subtracting the off current value (e.g., 0) from the on current value (e.g., Amax) by a predetermined coefficient (e.g., a value greater than or equal to 0.05 and less than or equal to 0.65) and provides the threshold Ath to the threshold recording unit 12.

[0050] Here, the current is measured by the current measuring unit 11 while the operating state (on or off) of the electric device 2 is unknown. The current measurement result is provided to the on / off determination unit 13. When the current exceeds the threshold Ath, the on / off determination unit 13 determines that the power supply of the electric device 2 is on. When the current is less than the threshold Ath, the on / off determination unit 13 determines that the power supply of the electric device 2 is off.

[0051] According to the sensor tag 1 of the first embodiment, the threshold Ath of the current flowing through the power cable 4 for determining whether the electrical device 2 connected to the power cable 4 is operating or not is derived by the threshold derivation unit 18 as being equal to or greater than the upper limit of the current at which the power supply of the electrical device 2 is reliably off and equal to or less than the lower limit of the current at which the power supply of the electrical device 2 is reliably on.

[0052] Second embodiment The sensor tag (operating state determining device) 1 according to the second embodiment differs from the first embodiment in that an ON / OFF current derivation instruction unit 15 is provided instead of the ON current derivation instruction unit 14a and the OFF current derivation instruction unit 14b.

[0053] 4 is a functional block diagram showing the configuration of a sensor tag (operating state determination device) 1 according to the second embodiment. The sensor tag 1 according to the second embodiment includes a current measurement unit 11, a threshold recording unit 12, an on / off determination unit 13, an on current derivation unit 14, an on / off current derivation instruction unit 15, an off current derivation unit 16, a notification unit 17, and a threshold derivation unit 18. Hereinafter, parts similar to those in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0054] The current measuring section 11, the threshold recording section 12, the on / off determining section 13 and the threshold derivation section 18 are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0055] The on-current derivation section 14 has an on-current average derivation section 14b but does not have an on-current derivation instruction section 14a.

[0056] The off-current derivation section 16 includes an off-current average derivation section 16b but does not include an off-current derivation instruction section 16a.

[0057] On / off current derivation instruction section 15 instructs on-current average derivation section 14b of on-current derivation section 14 and off-current average derivation section 16b of off-current derivation section 16 to perform derivation.

[0058] However, when the on / off current derivation instruction unit 15 receives a first operation, it instructs the on current derivation unit 14 to perform derivation, and when it receives a second operation, it instructs the off current derivation unit 16 to perform derivation.

[0059] Here, the on / off current derivation instruction unit 15 is, for example, a button pressed by a user. The first operation is, for example, the second (and fourth, sixth, ...) pressing of this button, and the second operation is, for example, the first (and third, fifth, ...) pressing of this button.

[0060] However, the user performs the second operation after confirming that the power supply of the electric appliance 2 is turned off, and performs the first operation after confirming that the power supply of the electric appliance 2 is turned on.

[0061] Notification unit 17 notifies the user that the first operation and the second operation have been received by ON / OFF current derivation instruction unit 15. For example, notification unit 17 is a display, and displays to the user that the first operation has been received (i.e., that the ON current has been derived) and that the second operation has been received (i.e., that the OFF current has been derived).

[0062] Next, the operation of the second embodiment will be described.

[0063] First, the power supply of the electric device 2 is turned off. Here, when the user confirms that the power supply of the electric device 2 is turned off and operates the on / off current derivation instruction unit 15 (first press of the button), the derivation of the off current value is instructed to the off current average derivation unit 16b. Furthermore, the notification unit 17 notifies the user that the second operation has been received (i.e., that the off current has been derived). Furthermore, the average value of the current measured by the current measurement unit 11 is derived as the off current by the off current average derivation unit 16b and provided to the threshold derivation unit 18.

[0064] Next, the power supply of the electric device 2 is turned on. Here, when the user confirms that the power supply of the electric device 2 is on and operates the on / off current derivation instruction unit 15 (presses the button a second time), the on-current average derivation unit 14b is instructed to derive the on-current value. Furthermore, the notification unit 17 notifies the user that the first operation has been received (i.e., that the on-current has been derived). Furthermore, the average value of the current measured by the current measurement unit 11 is derived as the on-current by the on-current average derivation unit 14b and provided to the threshold derivation unit 18.

[0065] The threshold derivation unit 18 derives the threshold Ath by multiplying the value obtained by subtracting the off current value (e.g., 0) from the on current value (e.g., Amax) by a predetermined coefficient (e.g., a value greater than or equal to 0.05 and less than or equal to 0.65) and provides the threshold Ath to the threshold recording unit 12.

[0066] The subsequent operations (that is, the determination of the operating state (on or off) of the electric device 2) are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0067] According to the sensor tag 1 of the second embodiment, the same effect as that of the first embodiment can be achieved by using an on / off current derivation instruction unit 15 (e.g., one button) instead of the on current derivation instruction unit 14a and the off current derivation instruction unit 14b (e.g., two buttons in total).

[0068] Third embodiment The sensor tag (operating state determination device) 1 according to the third embodiment differs from the first embodiment in that the ON current derivation section 14 and the OFF current derivation section 16 automatically update the values ​​of the ON current and the OFF current.

[0069] The sensor tag (operating state determination device) 1 according to the third embodiment includes a current measuring unit 11, a threshold recording unit 12, an on / off determination unit 13, an on current derivation unit 14, an off current derivation unit 16, and a threshold derivation unit 18. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0070] The current measuring section 11, the threshold recording section 12, the on / off determining section 13 and the threshold derivation section 18 are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0071] 5 is a functional block diagram showing a configuration of an on-current derivation unit 14 according to the third embodiment. The on-current derivation unit 14 has an on-current average derivation unit 14b, an on-current range derivation unit 14c, an on-current average recording unit 14d, an on-current range recording unit 14e, and an update determination unit 14f.

[0072] On-current average derivation unit 14b derives as the on-current the average value of the current measured by current measurement unit 11 within a predetermined period (e.g., 5 seconds). The initially derived on-current is provided to threshold derivation unit 18 and on-current average recording unit 14d.

[0073] In addition, on-current average derivation unit 14b repeatedly derives the average value (for example, deriving the average value of the measured values ​​from time t=0 to 5 seconds, deriving the average value of the measured values ​​from time t=5 to 10 seconds, and deriving the average value of the measured values ​​from time t=10 to 15 seconds), and even when an update instruction is received from update determination unit 14f, the derived on-current is provided to threshold derivation unit 18 and on-current average recording unit 14d.

[0074] On-current range deriving unit 14c derives a value (i.e., a range of measured values) obtained by subtracting the minimum value from the maximum value of the current measured by current measuring unit 11 within a predetermined period (e.g., 5 seconds). The initially derived range of measured values ​​is provided to on-current range recording unit 14e.

[0075] In addition, the on-current range derivation unit 14c repeatedly derives the range of measurement values ​​(for example, deriving the range of measurement values ​​from time t = 0 to 5 seconds, deriving the range of measurement values ​​from time t = 5 to 10 seconds, and deriving the range of measurement values ​​from time t = 10 to 15 seconds), and even when an update instruction is received from the update determination unit 14f, the derived range (the value obtained by subtracting the minimum value from the maximum value) is provided to the on-current range recording unit 14e.

[0076] The on-current average recording unit 14d records the output of the on-current average deriving unit 14b, and the on-current range recording unit 14e records the output of the on-current range deriving unit 14c.

[0077] When the output (average value of the measured current) of the ON current average derivation unit 14b exceeds the recorded content (the ON current value) of the ON current average recording unit 14d+(the recorded content of the ON current range recording unit 14e) / 2, the update determination unit 14f gives an update instruction to the ON current average derivation unit 14b and the ON current range derivation unit 14c. As a result, the average value of the measured current values ​​derived by the ON current average derivation unit 14b is given to the threshold derivation unit 18 as a new ON current value.

[0078] 6 is a functional block diagram showing a configuration of an off-current derivation unit 16 according to the third embodiment. The off-current derivation unit 16 has an off-current average derivation unit 16b, an off-current range derivation unit 16c, an off-current average recording unit 16d, an off-current range recording unit 16e, and an update determination unit 16f.

[0079] Off-current average derivation unit 16b derives as the off-current the average value of the current measured by current measurement unit 11 within a predetermined period (e.g., 5 seconds). The initially derived off-current is provided to threshold derivation unit 18 and off-current average recording unit 16d.

[0080] In addition, off-current average derivation unit 16b repeatedly derives the average value (for example, deriving the average value of measured values ​​from time t=0 to 5 seconds, deriving the average value of measured values ​​from time t=5 to 10 seconds, and deriving the average value of measured values ​​from time t=10 to 15 seconds), and even when an update instruction is received from update determination unit 16f, the derived off-current is provided to threshold derivation unit 18 and off-current average recording unit 16d.

[0081] Off-current range deriving unit 16c derives a value (i.e., a range of measured values) obtained by subtracting the minimum value from the maximum value of the current measured by current measuring unit 11 within a predetermined period (e.g., 5 seconds). The initially derived range of measured values ​​is provided to off-current range recording unit 16e.

[0082] In addition, off-current range derivation unit 16c repeatedly derives the range of measurement values ​​(for example, deriving the range of measurement values ​​from time t=0 to 5 seconds, deriving the range of measurement values ​​from time t=5 to 10 seconds, and deriving the range of measurement values ​​from time t=10 to 15 seconds), and even when an update instruction is received from update determination unit 16f, the derived range (the value obtained by subtracting the minimum value from the maximum value) is provided to off-current range recording unit 16e.

[0083] The off-current average recording unit 16d records the output of the off-current average deriving unit 16b, and the off-current range recording unit 16e records the output of the off-current range deriving unit 16c.

[0084] When the output (average value of the measured current) of the off-current average derivation unit 16b becomes less than the recorded content of the off-current average recording unit 16d (the value of the off-current)-(the recorded content of the off-current range recording unit 16e) / 2, the update determination unit 16f gives an update instruction to the off-current average derivation unit 16b and the off-current range derivation unit 16c. As a result, the average value of the measured current derived by the off-current average derivation unit 16b is given to the threshold derivation unit 18 as a new off-current value.

[0085] Next, the operation of the third embodiment will be described.

[0086] (1) When the power of electrical device 2 goes from off to on In this case, the average value of the measurements derived by the on-current average recording unit 14d continues to rise significantly. Therefore, the output (average value of the current measurements) of the on-current average derivation unit 14b continues to exceed the recorded contents of the on-current average recording unit 14d (the on-current value) + (the recorded contents of the on-current range recording unit 14e) / 2. Therefore, the on-current value provided to the threshold derivation unit 18 continues to be updated.

[0087] However, after a while after the power supply of the electric device 2 is turned on, the current becomes almost constant. Then, the output (average value of the measured current) of the on-current average derivation unit 14b does not exceed the recorded content of the on-current average recording unit 14d (the on-current value) + (the recorded content of the on-current range recording unit 14e) / 2. Then, the value of the on-current provided to the threshold derivation unit 18 does not fluctuate.

[0088] (2) When the power of electrical device 2 changes from on to off In this case, the average value of the measurements derived by the off-current average recording unit 16d continues to drop significantly. Therefore, the output (average value of the measured current) of the off-current average derivation unit 16b continues to be less than the recorded content of the off-current average recording unit 16d (the value of the off-current)-(the recorded content of the off-current range recording unit 16e) / 2. Therefore, the value of the off-current provided to the threshold derivation unit 18 continues to be updated.

[0089] However, after a while after the power supply of the electric device 2 is turned off, the current becomes almost constant. Then, the output (average value of the measured current) of the off-current average derivation unit 16b will not be less than the recorded content of the off-current average recording unit 16d (the value of the off-current)-(the recorded content of the off-current range recording unit 16e) / 2. Then, the value of the off-current provided to the threshold derivation unit 18 will not fluctuate.

[0090] In this way, after the on-current value and off-current value provided to the threshold derivation unit 18 become constant, the threshold derivation unit 18 multiplies the value obtained by subtracting the off-current value (e.g., 0) from the on-current value (e.g., Amax) by a predetermined coefficient (e.g., a value greater than or equal to 0.05 and less than or equal to 0.65) to derive the threshold Ath and provides it to the threshold recording unit 12.

[0091] The subsequent operations (that is, the determination of the operating state (on or off) of the electric device 2) are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0092] According to the sensor tag 1 of the third embodiment, the same effect as that of the first embodiment can be automatically achieved without using the on-current derivation instruction unit 14a and the off-current derivation instruction unit 14b (e.g., two buttons in total).

[0093] Fourth embodiment The sensor tag (operating state determination device) 1 in the fourth embodiment differs from the third embodiment in that the off-current derivation unit 16 derives the value of the off-current as the most frequent value of the measured current during the period when the power supply of the electrical device 2 is off.

[0094] 7 is a functional block diagram showing the configuration of a sensor tag (operating state determination device) 1 according to the fourth embodiment. The sensor tag 1 according to the fourth embodiment includes a current measuring unit 11, a threshold recording unit 12, an on / off determination unit 13, an on current derivation unit 14, an off current derivation unit 16, and a threshold derivation unit 18. Hereinafter, parts similar to those in the third embodiment are given the same reference numerals and description thereof will be omitted.

[0095] The current measuring unit 11, the threshold recording unit 12, the on / off determining unit 13, and the threshold derivation unit 18 are the same as those in the first and third embodiments, and therefore their explanations are omitted. The on-current derivation unit 14 is the same as that in the third embodiment (see FIG. 5), and therefore its explanation is omitted.

[0096] The off-current derivation unit 16 derives the value of the off-current as the most frequent value of the measured current during a period when the power supply of the electric device 2 is off. The off-current derivation unit 16 has a mode derivation unit 16g. The mode derivation unit 16g derives the most frequent value of the measured current by the current measurement unit 11 as the off-current, and provides the off-current to the threshold derivation unit 18. However, the mode derivation unit 16g operates during a period when the power supply of the electric device 2 is off.

[0097] Next, the operation of the fourth embodiment will be described.

[0098] First, the power supply of the electric device 2 is turned off. Here, when the user confirms that the power supply of the electric device 2 is turned off and operates the mode derivation unit 16g, the mode of the current measured by the current measurement unit 11 is derived as an off current by the mode derivation unit 16g and provided to the threshold derivation unit 18.

[0099] The next operation is similar to "(1) When the power supply of the electric device 2 is changed from OFF to ON" in the third embodiment, and therefore a description thereof will be omitted.

[0100] Furthermore, the subsequent operations (that is, the determination of the operating state (on or off) of the electric device 2) are similar to those in the first embodiment, and therefore the description thereof will be omitted.

[0101] The sensor tag 1 according to the fourth embodiment provides the same effects as those of the third embodiment.

[0102] The above embodiment can be realized as follows: A computer equipped with a CPU, a hard disk, and a media (USB memory, CD-ROM, etc.) reader reads a medium on which a program for implementing each of the above-mentioned parts, such as the threshold recording unit 12, the on / off determination unit 13, and the threshold derivation unit 18 of the sensor tag 1, is installed on the hard disk. The above-mentioned functions can also be realized in this manner. [Explanation of symbols]

[0103] 1. Sensor tag (operation status determination device) 2. Electrical Equipment 4 Power cable 6 batteries 11 Current measurement section 12 Threshold Recording Unit 13 On / off judgment section 14 On-current lead-out section 15 On / off current derivation indicator 16 Off-state current lead-out section 17. Notification Department 18 Threshold Derivation Part Ath Threshold

Claims

1. a current measuring unit for measuring a current of a power cable connected to an electrical device; an on / off determination unit that determines that the power supply of the electrical device is on when the current exceeds a threshold value, and that the power supply of the electrical device is off when the current is less than the threshold value; Equipped with The threshold value is The current is equal to or exceeds the upper limit for which the electrical device is sure to be turned off, and The electrical device is powered on at or below a lower limit of current. Operation status determination device.

2. The operating state determination device according to claim 1 , The current measuring unit is a non-contact sensor that does not come into contact with the power cable. Operation status determination device.

3. The operating state determination device according to claim 1 , A threshold derivation unit that derives the threshold; an on-current derivation unit that derives a value of an on-current that is a current when the power supply of the electrical device is on; an off-current derivation unit that derives a value of an off-current that is a current when a power source of the electrical device is off; Equipped with The threshold derivation unit, The operating state determination device derives the threshold value by multiplying a value obtained by subtracting the value of the off current from the value of the on current by a predetermined coefficient.

4. The operating state determination device according to claim 3, The on-current derivation unit derives the value of the on-current as an average value of the measured current values.

5. The operating state determination device according to claim 4, An operating state determination device in which, when the average value of the measured current exceeds the value of the on-current + (the maximum value of the measured current within a specified period - the minimum value of the measured current within a specified period) / 2, the average value of the measured current is set to the new value of the on-current.

6. The operating state determination device according to claim 3, The off-current derivation unit derives the value of the off-current as an average value of the measured current values.

7. The operating state determination device according to claim 4, An operating state determination device in which, when the average value of the measured current becomes less than the value of the off-current - (the maximum value of the measured current within a specified period - the minimum value of the measured current within a specified period) / 2, the average value of the measured current is set to the new value of the off-current.

8. The operating state determination device according to claim 3, The off-current derivation unit derives the value of the off-current as a mode of the measured current values ​​during a period in which the electrical equipment is powered off.

9. The operating state determination device according to claim 3, an on-current derivation instruction unit that instructs the on-current derivation unit to derive a value of the on-current; an off-current derivation instruction unit that instructs the off-current derivation unit to derive a value of the off-current; Equipped with The on-current derivation instruction unit and the off-current derivation instruction unit are separate from each other.

10. The operating state determination device according to claim 3, an on / off current derivation instruction unit that instructs the on current derivation unit and the off current derivation unit to perform derivation; The on / off current derivation instruction unit, When a first operation is received, an instruction is given to the on-current derivation unit to derive the on-current, When a second operation is received, the off-current derivation unit is instructed to perform derivation. Operation status determination device.

11. The operating state determination device according to claim 10, an operating state determination device including a notification unit that notifies that the on / off current derivation instruction unit has received the first operation and that the second operation has been received;

12. 1. An operating state determination method for determining an operating state of an electrical device by using a current measurement unit that measures a current in a power cable connected to the electrical device, comprising: an on / off determination step of determining that the power supply of the electrical device is on when the current exceeds a threshold value, and determining that the power supply of the electrical device is off when the current is less than the threshold value; The threshold value is The current is equal to or exceeds the upper limit for which the electrical device is sure to be turned off, and The electrical device is powered on at or below a lower limit of current. Method for determining operating status.

13. A computer-readable recording medium having recorded thereon a program for causing a computer to execute an operation state determination process for determining an operation state of an electrical device by using a current measurement unit that measures a current in a power cable connected to the electrical device, The operating state determination process includes: an on / off determination step of determining that the power supply of the electrical device is on when the current exceeds a threshold value, and determining that the power supply of the electrical device is off when the current is less than the threshold value; The threshold value is The current is equal to or exceeds the upper limit for which the electrical device is sure to be turned off, and The electrical device is powered on at or below a lower limit of current. Recording medium.

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