WO2022264680A1 - Monitoring device and activation method - Google Patents

Abstract

The present invention comprises: a power supply circuit that generates electric power from a first induced current obtained through electromagnetic induction coupling with an electric wire; a processor that operates with the electric power supplied from the power supply circuit; a current sensor that operates with the electric power, and measures the current flowing through the electric wire; an activation control circuit that activates the processor in accordance with the magnitude of the electric power generated by the power supply circuit; and a first circuit that is activated by the processor. The processor activates the current sensor in response to being activated by the activation control circuit, and activates the first circuit on the basis of the result of measurement of the current by the current sensor.

Description

Monitoring device and activation method

The present disclosure relates to monitoring devices and activation methods.
This application claims priority based on Japanese Patent Application No. 2021-99182 filed on June 15, 2021, and incorporates all of its disclosure herein.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2020-22217) discloses the following external wireless terminal. That is, the wireless terminal is a wireless terminal supplied with power from a battery, and includes a processor, a sensor module supplied with power from the battery by the processor during operation, and a plurality of constant current sources connected in parallel. and a battery voltage measuring circuit, wherein the processor receives a measurement request from the parent device and switches conduction states of a plurality of constant current sources of the battery voltage measuring circuit, thereby changing the load current of the battery. The battery voltage output from the battery is measured a plurality of times, the processor receives a measurement execution request from the parent device, supplies power to the sensor module to start it, and the measurement execution request is received from the parent device. Issued by the parent device when the sensor module determines that activation is possible based on the internal resistance of the battery calculated from the battery voltage measured multiple times by changing the load current of the battery.

In addition, Patent Document 2 (International Publication No. 2019/239783) discloses the following external power supply device. That is, the power supply device includes a power supply core provided to surround a power line, and a power supply core wound around the power supply core. a power supply current transformer unit having a power supply coil that generates a current; a power supply unit for supplying power, wherein the power supply core is adapted to allow the current to flow through the power line when the current value of the current flowing through the power line is a predetermined current value equal to or less than the allowable current value of the power line. configured to be magnetically saturated with respect to the magnetic field generated by

JP 2020-22217 A International Publication No. 2019/239783

A monitoring device of the present disclosure includes a power circuit that generates power from a first induced current obtained by electromagnetic induction coupling with a wire, a processor that operates on the power supplied from the power circuit, and a processor that operates on the power. , a current sensor that measures the current flowing through the wire, a start control circuit that starts the processor according to the magnitude of the power generated by the power supply circuit, and a first circuit that the processor starts, The processor activates the current sensor when activated by the activation control circuit, and activates the first circuit based on the current measurement result of the current sensor.

The activation method of the present disclosure includes a power supply circuit that generates power from a first induced current obtained by electromagnetic induction coupling with a wire, a processor that operates on the power, and a processor that operates on the power and generates a current flowing through the wire. A start-up method in a monitoring device comprising a current sensor to measure and a first circuit started by the processor, wherein the processor and the current sensor are started according to the magnitude of the power generated by the power supply circuit. and activating the first circuit based on the result of measurement of the current by the current sensor.

One aspect of the present disclosure can be implemented not only as a monitoring device including such a characteristic processing unit, but also as a program for causing a computer to execute steps of such characteristic processing. Further, one aspect of the present disclosure can be implemented as a semiconductor integrated circuit that implements part or all of the monitoring device, or can be implemented as a monitoring system that includes the monitoring device.

FIG. 1 is a diagram illustrating an example configuration of a monitoring device according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a threshold table stored in a storage unit in the monitoring device according to the embodiment of the present disclosure; FIG. 3 is a time chart showing activation timing of each circuit in the monitoring device according to the embodiment of the present disclosure. FIG. 4 is a flow chart defining an example of an operation procedure when activating each circuit in the monitoring device according to the embodiment of the present disclosure. FIG. 5 is a flowchart that defines an example of an operation procedure when the monitoring device according to the embodiment of the present disclosure performs activation determination processing. FIG. 6 is a diagram illustrating an example of a configuration of a monitoring device according to a modification of the embodiment of the present disclosure;

　Conventionally, a monitoring device equipped with various sensors and collecting measured values of the sensors has been developed as a device that constitutes a sensor network in, for example, M2M (Machine-to-Machine) and IoT (Internet of Things).

[Problems to be Solved by the Present Disclosure]
A technology capable of stably operating a monitoring device is desired beyond the technology described in Patent Documents 1 and 2.

The present disclosure has been made to solve the above-described problems, and its purpose is to provide a monitoring device and a startup method that can stably operate the monitoring device.

[Effect of the present disclosure]
According to the present disclosure, it is possible to stably operate the monitoring device.

[Description of Embodiments of the Present Disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.

(1) A monitoring device according to an embodiment of the present disclosure operates with a power supply circuit that generates power from a first induced current obtained by electromagnetic induction coupling with a wire, and the power supplied from the power supply circuit. a processor, a current sensor that operates on the power and measures the current flowing through the wire, a startup control circuit that starts the processor according to the magnitude of the power generated by the power supply circuit, and the processor that starts up. and a first circuit, wherein the processor activates the current sensor when activated by the activation control circuit, and activates the first circuit based on the current measurement result of the current sensor. do.

In this manner, the processor and the current sensor are activated according to the magnitude of the power generated by the power supply circuit, and the first circuit is activated based on the current measurement result of the current sensor. Since the processor can be started only in a state where the energy harvesting in the environment generates the power necessary for stable operation of the processor, it suppresses the restart of the processor due to insufficient power generated by the energy harvesting. be able to. Therefore, the monitoring device can be stably operated.

(2) The current sensor includes a first current transformer attached to the electric wire, and a calculator for calculating a current flowing through the electric wire based on a second induced current obtained by the first current transformer. It may be a configuration including.

With such a configuration, it is possible to more accurately grasp the state of the energy source of the power generated in the power supply circuit, and control activation of the first circuit according to the state.

(3) The monitoring device further includes a second current transformer for obtaining the first induced current, wherein the winding of the second current transformer and the winding of the first current transformer are , may be provided on a common magnetic core.

With this configuration, a single magnetic core can be used to both generate power and measure the current flowing through the wire at low cost.

(4) The monitoring device includes, as the first circuit, a communication unit and a first sensor other than the current sensor, and the processor compares the measurement result with a first threshold value. and activating the communication unit based on a comparison result between the measurement result and a second threshold value that is larger than the first threshold value. It may be configured to

With such a configuration, for example, when the power generated by the power supply circuit is relatively small, only the first sensor out of the communication unit and the first sensor is preferentially activated to activate the first sensor. By accumulating the measurement results by and activating the communication unit when the power generated by the power supply circuit is relatively large, the accumulated measurement results can be transmitted to, for example, an external management device. Missing measurement by one sensor can be reduced.

(5) The monitoring device includes, as the first circuit, a communication unit and a first sensor other than the current sensor, and the processor compares the measurement result with a first threshold value. and activating the communication unit based on a comparison result between the measurement result and a second threshold smaller than the first threshold. It may be configured to

With such a configuration, for example, when the power generated by the power supply circuit is relatively small, by preferentially activating only the communication unit of the communication unit and the first sensor, for example, the power supply circuit Even if the generated power is small, the result of measurement by the current sensor can be transmitted to the external management device via the communication unit.

(6) The monitoring device includes a plurality of the first circuits, the monitoring device further includes a storage unit that stores a plurality of threshold values based on current consumption of each of the first circuits, The processor activates one or more of the first circuits respectively corresponding to the plurality of thresholds based on the result of comparison between the measurement result and the plurality of thresholds. good too.

With such a configuration, it is possible to control activation of each circuit based on, for example, the activation priority of each circuit and the current consumption of each circuit.

(7) A startup method according to an embodiment of the present disclosure includes a power supply circuit that generates power from a first induced current obtained by electromagnetic induction coupling with a wire, a processor that operates on the power, and a processor that operates on the power. and a current sensor that measures the current flowing through the wire; and a first circuit that is activated by the processor. activating the processor and the current sensor; and activating the first circuit based on a measurement result of the current by the current sensor.

Thus, by activating the processor and the current sensor according to the magnitude of the power generated by the power supply circuit and activating the first circuit based on the current measurement result of the current sensor, for example, the power supply circuit Since the processor can be started only in a state where the energy harvesting in the environment generates the power necessary for stable operation of the processor, it suppresses the restart of the processor due to insufficient power generated by the energy harvesting. be able to. Therefore, the monitoring device can be stably operated.

Embodiments of the present disclosure will be described below with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. Moreover, at least part of the embodiments described below may be combined arbitrarily.

[Configuration and basic operation]
FIG. 1 is a diagram illustrating an example configuration of a monitoring device according to an embodiment of the present disclosure. Referring to FIG. 1, monitoring apparatus 101 includes activation control circuit 10, power supply circuit 11, MCU (Micro Controller Unit) 13, storage unit 14, communication unit 21, camera module 22, and external interface unit. 23 , a temperature sensor 24 , a current sensor 25 , and supply switches 31 , 32 , 33 , 34 , 35 . Activation control circuit 10 includes a voltage monitoring circuit 12 , a switch 41 and a load circuit 42 . Each of communication section 21, camera module 22, external interface section 23, and temperature sensor 24 is an example of a first circuit. Temperature sensor 24 is an example of a first sensor.

The storage unit 14 is, for example, a non-volatile memory. MCU 13 is an example of a processor. The communication unit 21 is realized by, for example, a communication IC (Integrated Circuit).

The switch 41 and the load circuit 42 are connected in series in this order between a node N1 between the power supply circuit 11 and the supply switches 31, 32, 33, 34, 35 and the ground. The switch 41 is, for example, a bipolar transistor or FET (Field Effect Transistor).

The monitoring device 101 is provided corresponding to the electric wire 71 . The electric wire 71 may be an overhead transmission line or an underground transmission line. The monitoring device 101 does not have a battery, but operates on power obtained from energy harvesting.

(Power supply circuit)
The power supply circuit 11 generates electric power from an induced current obtained by electromagnetic induction coupling with the electric wire 71 . The induced current is an example of a first induced current. For example, the power supply circuit 11 converts an induced current obtained through a current transformer 50 attached to the electric wire 71 into DC power necessary for operating each circuit in the monitoring device 101 .

More specifically, the current transformer 50 (hereinafter referred to as "CT50") includes a magnetic core 51 that clamps the electric wire 71 and a winding 52 wound around the magnetic core 51. Both ends of the winding 52 are connected to the power supply circuit 11 . CT50 is an example of a second current transformer.

The power supply circuit 11 receives from the CT 50 an induced current based on the magnetic field generated by the alternating current Iew flowing through the electric wire 71 . The power supply circuit 11 converts the induced current received from the CT 50 into DC power and outputs the obtained DC power.

The voltage monitoring circuit 12 , MCU 13 , communication unit 21 , camera module 22 , external interface unit 23 , temperature sensor 24 and current sensor 25 operate with power supplied from power supply circuit 11 .

(The camera module)
The camera module 22 receives power from the power supply circuit 11 via the supply switch 32 . Camera module 22 , for example, periodically captures an area around monitoring device 101 in an activated state, and outputs camera information indicating the obtained image to MCU 13 . Note that the camera module 22 may be configured to perform imaging in response to an imaging request received from the MCU 13 and output camera information to the MCU 13 .

(temperature sensor)
Temperature sensor 24 receives power from power supply circuit 11 via supply switch 34 . The temperature sensor 24 periodically measures the temperature around the monitoring device 101 and outputs temperature information indicating the temperature measurement value to the MCU 13 in the activated state. For example, the temperature sensor 24 measures the temperature of the wire 71 as the ambient temperature of the monitoring device 101 . The temperature sensor 24 may be configured to receive a measurement request from the MCU 13 and output temperature information to the MCU 13 as a response to the received measurement request.

(current sensor)
For example, current sensor 25 includes a current transformer 60 attached to electric wire 71 and a calculator 63 that calculates the current flowing through electric wire 71 , that is, alternating current Iew, based on the induced current obtained by current transformer 60 . The induced current is an example of a second induced current. Calculation unit 63 is implemented by a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor), for example.

More specifically, the current transformer 60 (hereinafter referred to as "CT60") includes a magnetic core 61 that clamps the electric wire 71 and a winding 62 wound around the magnetic core 61. Both ends of the winding 62 are connected to the calculator 63 . CT60 is an example of a first current transformer.

The calculator 63 receives from the CT 60 an induced current based on the magnetic field generated by the alternating current Iew flowing through the electric wire 71 . The calculator 63 calculates the effective value of the alternating current Iew as the measured current value Im based on the magnitude of the induced current received from the CT 60 , and outputs current information indicating the measured current value Im to the MCU 13 .

The calculator 63 receives power from the power supply circuit 11 via the supply switch 35 . Calculation unit 63 , for example, periodically calculates alternating current Iew in the activated state, and outputs current information indicating current measurement value Im to MCU 13 . The calculation unit 63 may be configured to receive a measurement request from the MCU 13 and output current information to the MCU 13 as a response to the received measurement request.

(communication department)
The communication unit 21 receives power from the power supply circuit 11 via the supply switch 31 . The communication unit 21 transmits temperature information, camera information, and current information to a management device (not shown) outside the monitoring device 101 in the activated state.

More specifically, when the MCU 13 receives an information transmission request from the management device, the MCU 13 outputs the temperature information received from the temperature sensor 24, the camera information received from the camera module 22, and the current information received from the current sensor 25 to the communication unit 21. do. Note that the MCU 13 may be configured to periodically output temperature information, camera information, and current information to the communication section 21 .

The communication unit 21 receives temperature information, camera information and current information from the MCU 13, and wirelessly transmits a wireless signal including a sensor packet storing the received temperature information, camera information and current information to the management device. The communication unit 21 and the management device are, for example, wireless LAN (Local Area Network), LTE (Long Term Evolution), 5G, 920 MHz band ZigBee (registered trademark), Bluetooth (registered trademark), UWB (Ultra Wide Band), etc. Performs wireless communication using a communication protocol. A communication protocol other than the above may be used between the communication unit 21 and the management device. In addition, the communication unit 21 may be configured to transmit the temperature information to the management device by wired communication using a wired transmission line such as an Ethernet (registered trademark) cable and a USB (Universal Serial Bus) cable. The temperature information may be transmitted to the management device by PLC (Power Line Communications) communication used. Further, the communication unit 21 may be configured not to transmit part of the temperature information, the camera information, and the current information to the management device.

(external interface)
The external interface section 23 receives power from the power supply circuit 11 via the supply switch 33 . The external interface unit 23 is connected to an external device (not shown). The external interface unit 23 transmits a control signal for controlling the external device to the external device in the activated state.

More specifically, the external interface unit 23 transmits a control signal for opening and closing an electronic lock, which is an example of an external device, to an electronic lock, and controls an air conditioner, which is an example of an external device, according to instructions from the MCU 13. For example, a control signal is sent to the air conditioner.

(Startup control circuit)
The activation control circuit 10 switches the MCU 13 between an activation state and a reset state. More specifically, voltage monitoring circuit 12 outputs to MCU 13 a reset control signal for switching the state of MCU 13 . As an example, the voltage monitoring circuit 12 switches the MCU 13 to the active state by switching the reset control signal output to the MCU 13 from low level to high level, and switches the reset control signal output to the MCU 13 from high level to low level. The MCU 13 is switched from the activation state to the reset state.

Also, the voltage monitoring circuit 12 switches the ON state and OFF state of the switch 41 by outputting a switch control signal to the switch 41 .

The voltage monitoring circuit 12 synchronizes the reset signal and the switch control signal so that the MCU 13 is reset when the switch 41 is on and the MCU 13 is activated when the switch 41 is off.

(MCU)
The MCU 13 controls power supply from the power supply circuit 11 to the communication unit 21, the camera module 22, the external interface unit 23, the temperature sensor 24, and the current sensor 25 in the activated state. More specifically, the MCU 13 outputs supply control signals to the supply switches 31, 32, 33, 34, and 35 to turn the supply switches 31, 32, 33, 34, and 35 on and off, respectively. switch.

(Activation of MCU and current sensor)
The activation control circuit 10 activates the MCU 13 according to the amount of power generated by the power supply circuit 11 . As an example, the voltage monitoring circuit 12 monitors the output voltage of the power supply circuit 11 and activates the MCU 13 based on the monitoring result.

More specifically, the voltage monitoring circuit 12 monitors the voltage Vout of the node N2 when the switch 41 is in the ON state and the MCU 13 is in the reset state. When the predetermined time T1 continues, the MCU 13 is switched from the reset state to the activated state by switching the switch 41 to the OFF state and switching the reset control signal from the low level to the high level. Predetermined time T1 is set, for example, based on the cycle of alternating current Iew flowing through electric wire 71 .

The MCU 13 activates the current sensor 25 as it is activated by the activation control circuit 10 . More specifically, when the MCU 13 is activated by the voltage monitoring circuit 12, the MCU 13 outputs a supply control signal to the supply switch 35, thereby switching the supply switch 35 from the supply OFF state to the supply ON state.

The current sensor 25 is activated by receiving power from the power supply circuit 11 via the supply switch 35 when the supply switch 35 transitions from the supply OFF state to the supply ON state. After being activated, the current sensor 25 starts measuring the alternating current Iew and periodically outputs current information to the MCU 13 .

Here, threshold Th1 is set based on the total current consumption of MCU 13 and current sensor 25 and the resistance value of load circuit 42 . More specifically, the amount of power generated by power supply circuit 11 depends on the effective value of alternating current Iew flowing through wire 71 . Threshold value Th1, for example, when the effective value of alternating current Iew flowing through electric wire 71 is X1 amperes, power supply circuit 11 outputs power obtained by adding power E to the power necessary for the operation of MCU 13 and current sensor 25. , and the voltage of the node N2 when the switch 41 is on. The electric power E is a margin for stably operating the MCU 13 and the current sensor 25, and is set in advance according to the time variation of the effective value of the alternating current Iew. Specifically, the magnitude of the time variation of the effective value of the alternating current Iew depends on the environment of the installation location of the CT50. The power E is appropriately set according to the environment of the installation location of the CT 50. For example, when the CT 50 is installed in a location where the effective value of the alternating current Iew varies with time, it is set to a large value. When the CT 50 is installed in a place where the time variation of the effective value of the current Iew is small, it is set to a small value. Power E may be zero.

(activation of other circuits)
The MCU 13 activates other circuits in the monitoring device 101 , that is, the communication section 21 , the camera module 22 , the external interface section 23 and the temperature sensor 24 based on the result of measurement of the alternating current Iew by the current sensor 25 .

More specifically, the MCU 13 receives the current information from the current sensor 25, and based on the current measurement value Im indicated by the received current information, determines whether the communication unit 21 can be activated, whether the camera module 22 can be activated, and whether the external interface can be activated. Activation determination processing for determining whether the unit 23 can be activated and whether the temperature sensor 24 can be activated is performed. That is, the MCU 13 performs activation determination processing based on the energy harvesting capacity of the power supply circuit 11 estimated from the current measurement value Im.

FIG. 2 is a diagram showing an example of a threshold table stored in the storage unit of the monitoring device according to the embodiment of the present disclosure. Referring to FIG. 2, storage unit 14 stores a threshold table TBL showing a plurality of thresholds based on current consumption of communication unit 21, camera module 22, external interface unit 23 and temperature sensor 24. .

The threshold table TBL shows the correspondence between one or more circuits to be activated and the thresholds set for the current measurement value Im. Specifically, the threshold value table TBL should activate the temperature sensor 24 when the measured current value Im is equal to or greater than the threshold value Tha, and should activate the temperature sensor 24 when the measured current value Im is equal to or greater than the threshold value Thb. The temperature sensor 24 and the communication unit 21 should be activated, and the temperature sensor 24, the communication unit 21 and the camera module 22 should be activated when the current measurement value Im is equal to or greater than the threshold value Thc, and the current measurement value Im is equal to or greater than the threshold Thd, the temperature sensor 24, communication unit 21, camera module 22, and external interface unit 23 should be activated.

Threshold values Tha, Thb, Thc, and Thd in the threshold value table TBL are values of the AC current Iew when the power supply circuit 11 generates power necessary for stably operating one or more corresponding circuits. Set based on actual value.

More specifically, for example, the current consumption of temperature sensor 24 is 100 milliamperes, the total current consumption of temperature sensor 24 and communication unit 21 is 125 milliamperes, and the consumption of temperature sensor 24, communication unit 21 and camera module 22 is 125 milliamperes. The total current is 200 milliamperes, and the total current consumption of the temperature sensor 24, communication section 21, camera module 22 and external interface section 23 is 250 milliamperes.

It is assumed that the power supply circuit 11 can generate power necessary for operating the temperature sensor 24 when the effective value of the alternating current Iew is 80 amperes or more. In this case, the threshold Tha is set to 90 amperes, for example. That is, the threshold value Tha is set to a value obtained by adding 10 amperes as a margin Ma to 80 amperes, which is the effective value of the alternating current Iew when the power supply circuit 11 generates the power necessary for operating the temperature sensor 24. be done.

Also, it is assumed that the power supply circuit 11 can generate power necessary for operating the temperature sensor 24 and the communication unit 21 when the effective value of the alternating current Iew is 100 amperes or more. In this case, the threshold Thb is set to 110 amperes, for example. That is, the threshold value Thb is obtained by adding 10 amperes as a margin Mb to 100 amperes, which is the effective value of the alternating current Iew when the power supply circuit 11 generates the power necessary for operating the temperature sensor 24 and the communication unit 21. set to the value

Also, it is assumed that the power supply circuit 11 can generate power necessary for operating the temperature sensor 24, the communication unit 21, and the camera module 22 when the effective value of the alternating current Iew is 160 amperes or more. In this case, threshold Thc is set to 170 amperes, for example. That is, the threshold Thc is set to 160 amperes, which is the effective value of the AC current Iew when the power supply circuit 11 generates the power necessary for operating the temperature sensor 24, the communication unit 21, and the camera module 22, and the margin Mc It is set to add 10 amps.

Moreover, the power supply circuit 11 can generate power necessary for operating the temperature sensor 24, the communication unit 21, the camera module 22, and the external interface unit 23 when the effective value of the alternating current Iew is 200 amperes or more. do. In this case, the threshold Thd is set to 210 amperes, for example. That is, the threshold Thd is 200 amperes, which is the effective value of the alternating current Iew when the power supply circuit 11 generates the power necessary for operating the temperature sensor 24, the communication unit 21, the camera module 22, and the external interface unit 23. , plus a margin Md of 10 amperes.

Note that the margins Ma, Mb, Mc, and Md are not limited to 10 amperes. Also, some or all of the margins Ma, Mb, Mc, and Md may have different values.

For example, when the MCU 13 receives an update request from a management device (not shown) outside the monitoring device 101, the MCU 13 updates the thresholds Tha, Thb, Thc, and Thd in the threshold table TBL according to the received update request.

Based on the result of comparison between the result of measurement by the current sensor 25 and the plurality of threshold values in the threshold value table TBL, the MCU 13 selects the One or a plurality of circuits corresponding to threshold values Tha, Thb, Thc, and Thd are activated.

For example, the MCU 13 activates the temperature sensor 24 based on the result of comparison between the measurement result of the current sensor 25 and the threshold value Tha, and the measurement result of the current sensor 25 and the threshold value Thb larger than the threshold value Tha. The communication unit 21 is activated based on the comparison result. Threshold Tha is an example of a first threshold. Threshold Thb is an example of a second threshold.

More specifically, the MCU 13 activates the temperature sensor 24 when the current measurement value Im indicated by the current information received from the current sensor 25 is greater than or equal to the threshold value Tha. Further, the MCU 13 activates the temperature sensor 24 and the communication unit 21 when the current measurement value Im indicated by the current information received from the current sensor 25 is equal to or greater than the threshold value Thb.

FIG. 3 is a time chart showing activation timing of each circuit in the monitoring device according to the embodiment of the present disclosure. In FIG. 3, the horizontal axis is time, and the vertical axis is the effective value [A] of the alternating current Iew. For example, at time t0, switch 41 is on and MCU 13 is reset.

Referring to FIG. 3, voltage monitoring circuit 12 detects that voltage Vout at node N2 has become equal to or greater than threshold Th1 when the effective value of alternating current Iew flowing through electric wire 71 becomes equal to or greater than X1 amperes at time t1. This is detected and the MCU 13 is switched from the reset state to the active state. When activated by the voltage monitoring circuit 12, the MCU 13 activates the current sensor 25 by switching the supply switch 35 from the supply OFF state to the supply ON state.

Next, at time t2, when the measured current value Im indicated by the current information received from the current sensor 25 becomes equal to or greater than the threshold value Tha, the MCU 13 switches the supply switch 34 from the supply off state to the supply on state to turn on the temperature sensor. 24 is further activated.

Next, at time t3, when the current measurement value Im indicated by the current information received from the current sensor 25 becomes equal to or greater than the threshold value Thb, the MCU 13 switches the supply switch 31 from the supply OFF state to the supply ON state, thereby 21 is further activated.

Next, at time t4, when the measured current value Im indicated by the current information received from the current sensor 25 becomes equal to or greater than the threshold value Thc, the MCU 13 switches the supply switch 32 from the supply OFF state to the supply ON state, thereby turning the camera module on. 22 is further activated.

Next, at time t5, when the measured current value Im indicated by the current information received from the current sensor 25 becomes equal to or greater than the threshold value Thd, the MCU 13 switches the supply switch 33 from the supply OFF state to the supply ON state, thereby Activating the unit 23 further.

Next, for example, when the power supplied from the power supply circuit 11 drops, the MCU 13 switches the supply switches 31, 32, 33, 34, and 35 in stages as the power supplied from the power supply circuit 11 drops. By switching to the supply off state, the active circuit is brought to a halt state.

More specifically, when the current measurement value Im indicated by the current information received from the current sensor 25 becomes equal to or less than the threshold Thdx, the MCU 13 switches the supply switch 33 from the supply-on state to the supply-off state so that the external interface unit 23 to stop. Further, when the current measurement value Im indicated by the current information received from the current sensor 25 becomes equal to or less than the threshold value Thcx, the MCU 13 switches the supply switch 32 from the supply ON state to the supply OFF state, thereby further stopping the camera module 22. to Further, when the current measurement value Im indicated by the current information received from the current sensor 25 becomes equal to or less than the threshold value Thbx, the MCU 13 switches the supply switch 31 from the supply ON state to the supply OFF state, thereby further stopping the communication unit 21. to Further, when the current measurement value Im indicated by the current information received from the current sensor 25 becomes equal to or less than the threshold value Thax, the MCU 13 switches the supply switch 34 from the supply ON state to the supply OFF state, thereby further stopping the temperature sensor 24. to

For example, the threshold Thdx is greater than or equal to the threshold Thc and less than the threshold Thd. Also, for example, threshold Thcx is equal to or greater than threshold Thb and less than threshold Thc. Also, for example, the threshold Thbx is equal to or greater than the threshold Tha and less than the threshold Thb. Also, for example, the threshold Thax is greater than or equal to X1 and less than the threshold Tha.

The voltage monitoring circuit 12 monitors the power supplied from the power supply circuit 11 to the MCU 13. When the power supplied from the power supply circuit 11 to the MCU 13 becomes less than a predetermined value, the voltage monitoring circuit 12 turns on the switch 41 and outputs a reset control signal. By switching from the high level to the low level, the MCU 13 is switched from the activation state to the reset state.

At least one of the thresholds Tha, Thb, Thc, and Thd may be smaller than the value of X1. More specifically, the value of X1 may be greater than at least one of thresholds Tha, Thb, Thc, and Thd depending on the set value of power E1 described above.

For example, the value of X1 is greater than threshold Tha and less than threshold Thb. In this case, the MCU 13 is switched from the reset state to the activated state by the voltage monitoring circuit 12 at time t1, and activates the current sensor 25 . The MCU 13 further activates the temperature sensor 24 because the current measurement value Im indicated by the current information first received from the current sensor 25 after activation of the current sensor 25 is greater than or equal to the threshold value Tha.

[Flow of operation]
A monitoring device according to an embodiment of the present disclosure includes a computer including a memory, and an arithmetic processing unit such as an MCU in the computer reads a program including part or all of the steps of the following flowcharts and sequences from the memory. Read and execute. Programs for these multiple devices can each be installed from the outside. Programs for these devices are distributed in a state stored in recording media or via communication lines.

FIG. 4 is a flow chart defining an example of an operation procedure when activating each circuit in the monitoring device according to the embodiment of the present disclosure.

Referring to FIG. 4, first, voltage monitoring circuit 12 in monitoring device 101 starts monitoring voltage Vout of node N2 when switch 41 is in the ON state and MCU 13 is in the reset state (step S102).

Next, voltage monitoring circuit 12 waits for the state in which voltage Vout of node N2 is equal to or higher than threshold Th1 to continue for a predetermined time T1 (NO in step S104), and voltage Vout of node N2 is equal to or higher than threshold Th1. If this state continues for a predetermined time T1 (YES in step S104), the MCU 13 is switched from the reset state to the activated state (step S106).

Next, when activated by the voltage monitoring circuit 12, the MCU 13 activates the current sensor 25 by switching the supply switch 35 from the supply OFF state to the supply ON state (step S108).

Next, the MCU 13 performs activation determination processing based on the current measurement value Im indicated by the current information received from the current sensor 25 .

Next, when the power supplied from the power supply circuit 11 to the MCU 13 becomes less than the predetermined value (YES in step S112), the voltage monitoring circuit 12 switches the switch 41 to the ON state and changes the reset control signal from high level to low level. , the MCU 13 is switched from the activation state to the reset state (step S114).

Next, the voltage monitoring circuit 12 starts monitoring the voltage Vout of the node N2 again (step S102).

FIG. 5 is a flowchart that defines an example of an operation procedure when the monitoring device according to the embodiment of the present disclosure performs activation determination processing. FIG. 5 shows details of step S110 in FIG.

Referring to FIG. 5, first, MCU 13 waits for current measured value Im to exceed threshold value Tha (NO in step S202), and when current measured value Im exceeds threshold value Tha (step YES in S202), the temperature sensor 24 is activated (step S204).

Next, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold value Thb or the measured current value Im to become equal to or less than the threshold value Thax (NO in step S206 and NO in step S208).

Next, when the measured current value Im is equal to or less than the threshold value Thax (YES in step S208), the MCU 13 stops the temperature sensor 24 (step S210). Then, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold value Tha again (NO in step S202).

On the other hand, the MCU 13 activates the communication unit 21 when the measured current value Im is equal to or greater than the threshold value Thb (YES in step S206) (step S212).

Next, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold value Thc or the measured current value Im to become equal to or less than the threshold value Thbx (NO in step S214 and NO in step S216).

Next, when the measured current value Im becomes equal to or less than the threshold value Thbx (YES in step S216), the MCU 13 stops the communication unit 21 (step S218). Then, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold value Thb again, or for the measured current value Im to become equal to or less than the threshold value Thax (NO in step S206 and NO in step S208).

On the other hand, the MCU 13 activates the camera module 22 when the current measurement value Im is equal to or greater than the threshold value Thc (YES in step S214) (step S220).

Next, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold Thd or to become equal to or less than the threshold Thcx (NO in step S222 and NO in step S224).

Next, when the current measurement value Im is equal to or less than the threshold value Thcx (YES in step S224), the MCU 13 stops the camera module 22 (step S226). Then, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold value Thc again, or the measured current value Im to become equal to or less than the threshold value Thbx (NO in step S214 and NO in step S216).

On the other hand, when the current measurement value Im is equal to or greater than the threshold value Thd (YES in step S222), the MCU 13 activates the external interface unit 23 (step S228).

Next, the MCU 13 waits for the measured current value Im to become equal to or less than the threshold Thdx (NO in step S230), and when the measured current value Im becomes equal to or less than the threshold Thdx (YES in step S230), the external The interface unit 23 is brought into a stopped state (step S232). Then, the MCU 13 waits for the measured current value Im to become equal to or greater than the threshold Thd again, or the measured current value Im to become equal to or less than the threshold Thcx (NO in step S222 and NO in step S224).

Although the monitoring device 101 according to the embodiment of the present disclosure is configured to include the temperature sensor 24, it is not limited to this. Monitoring device 101 may be configured to include other sensors instead of temperature sensor 24 or in addition to temperature sensor 24 . In this case, the MCU 13 activates the other sensor based on the measurement result of the alternating current Iew by the current sensor 25 .

Also, although the monitoring device 101 according to the embodiment of the present disclosure is configured to include the communication unit 21, the camera module 22, the external interface unit 23, and the temperature sensor 24, it is not limited to this. The monitoring device 101 may be configured without some or all of the communication unit 21 , the camera module 22 , the external interface unit 23 and the temperature sensor 24 . Also, the MCU 13 activates the communication unit 21, the camera module 22, the external interface unit 23, and the temperature sensor 24 based on the result of the measurement of the alternating current Iew by the current sensor 25 and the result of comparison with one threshold value. may be

Further, in the monitoring device 101 according to the embodiment of the present disclosure, in the threshold table TBL in the storage unit 14, the threshold Thd, the threshold Thc, the threshold Thb, and the threshold Tha are larger in this order. value, but is not limited to this. The magnitude relationships among the thresholds Tha, Thb, Thc, and Thd may be interchanged according to the activation priority of the corresponding circuits. For example, when current information among temperature information, camera information, and current information should be preferentially transmitted to a management device (not shown) outside the monitoring device 101, the communication unit 21 is preferentially activated over the temperature sensor 24. Therefore, the threshold Thb is set to a value smaller than the threshold Tha.

Also, in the monitoring device 101 according to the embodiment of the present disclosure, the current sensor 25 is configured to measure the alternating current Iew via the CT 60, but the configuration is not limited to this. The current sensor 25 may be configured to measure the alternating current Iew flowing through the wire 71 based on the output voltage of the power supply circuit 11 . Also, the current sensor 25 may be configured to measure the alternating current Iew via a magnetic sensor attached to the electric wire 71 .

Further, in the monitoring device 101 according to the embodiment of the present disclosure, the MCU 13 is configured to perform activation determination processing based on the current measurement value Im indicated by the current information received from the current sensor 25. It is not limited. The MCU 13 may be configured to perform a process of switching the operation mode of the circuit being activated to, for example, a low power consumption operation mode, in addition to the activation determination process, based on the current measurement value Im.

Also, although the monitoring device 101 according to the embodiment of the present disclosure is configured to include the voltage monitoring circuit 12, it is not limited to this. The monitoring device 101 may be configured to include a current monitoring circuit instead of the voltage monitoring circuit 12 . The current monitoring circuit monitors the current that is output from the power supply circuit 11 and flows through the load circuit 42, and activates the MCU 13 based on the monitoring result.

<Modification>
FIG. 6 is a diagram illustrating an example of a configuration of a monitoring device according to a modification of the embodiment of the present disclosure; Referring to FIG. 6, monitoring device 102 includes power supply circuit 11A instead of power supply circuit 11 and current sensor 25A instead of current sensor 25, as compared with monitoring device 101 . Current sensor 25A includes a current transformer 80 attached to electric wire 71 and a calculator 63A that calculates alternating current Iew based on the induced current obtained by current transformer 80 .

A current transformer 80 (hereinafter referred to as "CT80") includes a magnetic core 81 that clamps an electric wire 71, and windings 82 and 83 wound around the magnetic core 81. A winding 82 of CT 80 and a winding 83 of CT 80 are provided on a common magnetic core 81 . CT80 is an example of a first current transformer and an example of a second current transformer.

Both ends of the winding 82 are connected to the power supply circuit 11A. Both ends of the winding 83 are connected to the calculator 63A.

The power supply circuit 11A converts the induced current obtained through the CT 80 attached to the electric wire 71 into DC power necessary for the operation of each circuit in the monitoring device 101.

By the way, a technology that can stably operate a monitoring device is desired. More specifically, a monitoring device equipped with a battery can stably operate for a certain period of time with power supplied from the battery. Battery needs to be replaced. In addition, rechargeable secondary batteries have the problem of deterioration due to repeated charging.

In order to solve these problems caused by using a battery as a power source, technology has been developed to operate a monitoring device using power obtained from energy harvesting.

However, since the amount of power obtained from energy harvesting fluctuates according to the state of the energy source, the monitoring device may be restarted repeatedly and the monitoring device may not operate stably.

On the other hand, in the monitoring devices 101 and 102 according to the embodiment of the present disclosure, the power supply circuit 11 generates electric power from the induced current obtained by electromagnetic induction coupling with the electric wire 71 . The MCU 13 operates with power supplied from the power supply circuit 11 . The current sensor 25 operates with power supplied from the power supply circuit 11 and measures the current flowing through the wire 71 . The activation control circuit 10 activates the MCU 13 according to the amount of power generated by the power supply circuit 11 . The MCU 13 activates the current sensor 25 when activated by the activation control circuit 10, and based on the current measurement result of the current sensor 25, the communication unit 21, the camera module 22, the external interface unit 23, and the temperature sensor 24. to start.

In this way, the processor and the current sensor are activated according to the magnitude of the power generated by the power supply circuit, and the communication unit 21, the camera module 22, the external interface unit 23, and the temperature sensor are activated based on the current measurement result of the current sensor. The configuration for activating the sensor 24 allows the processor to be activated only in conditions where, for example, the energy harvesting in the power supply circuit generates the power necessary for stable operation of the processor, so that the power generated by the energy harvesting is unnecessary. A restart of the processor due to being sufficient can be suppressed. Therefore, in the embodiment of the present disclosure, it is possible to stably operate the monitoring devices 101 and 102 .

Further, in the monitoring devices 101 and 102 according to the embodiment of the present disclosure, activation processing of the MCU 13 and the current sensor 25, and activation processing of the communication unit 21, the camera module 22, the external interface unit 23, and the temperature sensor 24 are performed by external It can be performed in the monitoring devices 101 and 102 regardless of the device.

The above embodiments should be considered as examples in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims.

The above description includes the features appended below.
[Appendix 1]
A monitoring device,
a power supply circuit that generates power from a first induced current obtained by electromagnetic inductive coupling with a wire;
a processor that operates on the power supplied from the power supply circuit;
a current sensor that operates on the power and measures the current flowing through the wire;
an activation control circuit that activates the processor according to the magnitude of power generated by the power supply circuit;
a first circuit initiated by the processor;
The processor activates the current sensor when activated by the activation control circuit, activates the first circuit based on the current measurement result of the current sensor,
The monitoring device includes, as the first circuit, a communication unit and a first sensor other than the current sensor,
The monitoring device, wherein the communication unit is realized by a communication IC and transmits the measurement result of the first sensor to a management device outside the monitoring device.

REFERENCE SIGNS LIST 10 startup control circuit 11, 11A power supply circuit 12 voltage monitoring circuit 13 MCU
14 storage unit 21 communication unit 22 camera module 23 external interface unit 24 temperature sensor 25, 25A current sensor 31, 32, 33, 34, 35 supply switch 41 switch 42 load circuit 51, 61, 81 magnetic core 52, 62, 82, 83 Winding 50, 60, 80 CT
63, 63A calculator 71 electric wire 101, 102 monitoring device N1, N2 node TBL threshold table

Claims (7)

1. A monitoring device,
   a power supply circuit that generates power from a first induced current obtained by electromagnetic inductive coupling with a wire;
   a processor that operates on the power supplied from the power supply circuit;
   a current sensor that operates on the power and measures the current flowing through the wire;
   an activation control circuit that activates the processor according to the magnitude of power generated by the power supply circuit;
   a first circuit initiated by the processor;
   The monitoring device, wherein the processor activates the current sensor when activated by the activation control circuit, and activates the first circuit based on a measurement result of the current by the current sensor.
2. The current sensor is
   a first current transformer attached to the electric wire;
   2. The monitoring device according to claim 1, further comprising a calculator that calculates the current flowing through the wire based on the second induced current obtained by the first current transformer.
3. The monitoring device further
   A second current transformer for obtaining the first induced current,
   3. The monitoring device according to claim 2, wherein windings of said second current transformer and windings of said first current transformer are provided on a common magnetic core.
4. The monitoring device includes, as the first circuit, a communication unit and a first sensor other than the current sensor,
   The processor activates the first sensor based on a comparison result between the measurement result and a first threshold, and outputs the measurement result and a second sensor larger than the first threshold. The monitoring device according to any one of claims 1 to 3, wherein the communication unit is activated based on the result of comparison with a threshold value.
5. The monitoring device includes, as the first circuit, a communication unit and a first sensor other than the current sensor,
   The processor activates the first sensor based on a result of comparison between the measurement result and a first threshold, and outputs the measurement result and a second sensor smaller than the first threshold. The monitoring device according to any one of claims 1 to 3, wherein the communication unit is activated based on the result of comparison with a threshold value.
6. The monitoring device comprises a plurality of the first circuits,
   The monitoring device further
   A storage unit that stores a plurality of threshold values based on current consumption of each of the first circuits,
   3. The processor activates one or more of the first circuits respectively corresponding to the plurality of thresholds based on the result of comparison between the measurement result and the plurality of thresholds. A monitoring device according to any one of claims 1 to 3.
7. a power supply circuit that generates power from a first induced current obtained by electromagnetic induction coupling with a wire; a processor that operates on the power; a current sensor that operates on the power and measures the current flowing through the wire; A start-up method in a monitoring device comprising a first circuit that a processor starts,
   activating the processor and the current sensor according to the amount of power generated by the power supply circuit;
   and activating the first circuit based on the measurement result of the current by the current sensor.

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