JP7239378B2 - Communication device, communication system, communication method, and program - Google Patents

Description

The present disclosure relates to communication devices, communication systems, management devices, and communication methods.

Japanese Patent Laid-Open No. 2002-200002 describes a technique related to tracking of packages transported by vehicle.

Japanese Patent Application Laid-Open No. 2002-029606

Tracking of cargo transported by ship requires reducing the power consumption of equipment attached to the cargo.

SUMMARY OF THE DISCLOSURE It is an object of the present disclosure to reduce the power consumption of cargo-mounted equipment for tracking cargo transported on ships.

A communication device according to an embodiment of the present disclosure,
Used attached to cargo,
a sound detection unit that detects sound;
a positioning unit that measures a position;
a communication unit that communicates with the management device;
determining whether or not the sound detected by the sound detection unit is the whistle of a ship, and determining the position on the ocean measured by the positioning unit according to the result of the determination and the result of positioning by the positioning unit; A control unit that selects one of an offshore mode that performs control for notification from the communication unit to the management device and a low power consumption mode that does not perform the control.

A management device according to an embodiment of the present disclosure,
Each is attached to cargo, detects sound, judges whether the detected sound is a ship's whistle, and processes to notify the measured position on the sea according to the result of the judgment and the result of positioning. a communication unit that selects either an offshore mode to perform the processing or a low power consumption mode that does not perform the processing, and communicates with a plurality of communication devices that transition to the selected mode;
When the plurality of communication devices are in the ocean mode and the difference in position notified from the plurality of communication devices to the communication unit is equal to or less than a specified value, the plurality of communication devices via the communication unit and a control unit that causes at least one second communication device, excluding the first communication device, to transition to the low power consumption mode.

In a communication method according to an embodiment of the present disclosure,
A communication device attached to cargo detects sound, determines whether the detected sound is a ship's whistle, and manages the measured position on the ocean according to the result of the determination and the result of positioning. Either the ocean mode in which the process of notifying the device is performed or the low power consumption mode in which the process is not performed is selected, and the mode is changed to the selected mode.

According to an embodiment of the present disclosure, the power consumption of a cargo-mounted device for tracking cargo transported on a ship may be reduced.

1 is a diagram showing the configuration of a communication system according to an embodiment of the present disclosure; FIG. 1 is a block diagram showing the configuration of a communication device according to an embodiment of the present disclosure; FIG. 3 is a block diagram showing the configuration of a sound detection unit of the communication device according to one embodiment of the present disclosure; FIG. 1 is a block diagram showing the configuration of a management device according to an embodiment of the present disclosure; FIG. 4 is a flow chart showing operation of a communication device according to an embodiment of the present disclosure; 9 is a flowchart showing operations of a communication device according to a modified example of an embodiment of the present disclosure;

An embodiment of the present disclosure will be described below with reference to the drawings.

In each figure, the same reference numerals are given to the same or corresponding parts. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

An overview of the present embodiment will be described with reference to FIG.

In the communication system 10 according to this embodiment, the communication device 20 is attached to the cargo 11 . Communication device 20 detects sound. The communication device 20 determines whether the detected sound is the whistle of the ship 12 . The communication device 20 selects one of the ocean mode and the low power consumption mode according to the determination result and the positioning result. The communication device 20 transitions to the selected mode.

The offshore mode is a mode in which a process of notifying the management device 30 of the offshore position measured by the communication device 20 is performed. The low power consumption mode is a mode in which the communication device 20 does not perform the processing.

Specifically, the ocean mode is a mode in which the communication device 20 intermittently performs positioning while moving on the ocean and transmits the position information to the management device 30 . The low power consumption mode is a mode in which the communication device 20 waits for an acceleration sensor interrupt and a key press. Low power consumption mode is also called PSM. "PSM" is an abbreviation for power saving mode. The low power consumption mode may be eDRX defined in 3GPP LTE Release 13. "3GPP" is an abbreviation for 3rd Generation Partnership Project. "LTE" is an abbreviation for Long Term Evolution. "eDRX" is an abbreviation for Extended Discontinuous Reception.

Modes of the communication device 20 include an operation mode and a power off mode in addition to the ocean mode and the low power consumption mode. The active mode is a mode in which the processor of the communication device 20 always operates. The power off mode is a mode in which the communication device 20 is in a battery voltage applied state and waits only for activation factors such as power key depression, USB connection, and external interface connection. "USB" is an abbreviation for Universal Serial Bus.

Modes of the communication device 20 may include modes other than the operating mode, the ocean mode, the low power consumption mode, and the power off mode.

In this embodiment, the communication device 20 transitions from the low power consumption mode to the ocean mode when it detects that the tracked object has started to move, and starts tracking, but does not communicate with the management device 30 until then. Therefore, according to this embodiment, the power consumption of the communication device 20 attached to the cargo 11 for tracking the cargo 11 transported by the ship 12 can be reduced.

The communication device 20 may detect that the tracked object has started to move due to an acceleration sensor interrupt that occurs in the low power consumption mode. However, when the ship 12 leaves the port 13, the change in the measured value of the acceleration sensor is small, so the communication device 20 may not be able to detect that the tracking target has started moving, and may not be able to transition from the low power consumption mode to the ocean mode. There is Therefore, in this embodiment, a whistle sounded when the ship 12 leaves the port 13 is used as a trigger for transitioning from the low power consumption mode to the ocean mode. This makes it easier to detect that the tracking target has started to move.

The configuration of the communication system 10 will be described with reference to FIG.

The communication system 10 includes multiple communication devices 20 and a management device 30 . In this embodiment, the communication system 10 includes four communication devices 20, ie, a communication device A1, a communication device A2, a communication device A3, and a communication device A4, as a plurality of communication devices 20. However, one or more communication devices 20 should be provided.

Each communication device 20 is attached to the cargo 11 and used. Although the cargo 11 is a container in this embodiment, it may be anything that is transported by the ship 12 .

Each communication device 20 can communicate with the management device 30 via a network 40 such as a mobile communication network and the Internet.

The management device 30 is installed at an arbitrary location such as a data center. The management device 30 is configured as a server belonging to a system such as a cloud.

The configuration of the communication device 20 according to the present embodiment will be described with reference to FIG.

The communication device 20 includes a control section 21 , a storage section 22 , a communication section 23 , a positioning section 24 , a sound detection section 25 , an acceleration sensor 26 and a battery 27 .

The control unit 21 is one or more processors. A processor may be a general-purpose processor, such as a CPU, or a dedicated processor specialized for a particular process. "CPU" is an abbreviation for central processing unit. The controller 21 may include one or more dedicated circuits, or one or more processors may be replaced with one or more dedicated circuits in the controller 21 . A dedicated circuit is, for example, an FPGA or an ASIC. "FPGA" is an abbreviation for field-programmable gate array. "ASIC" is an abbreviation for application specific integrated circuit. The control unit 21 executes information processing related to the operation of the communication device 20 while controlling each unit of the communication device 20 .

The storage unit 22 is one or more memories. The memory is for example a semiconductor memory, a magnetic memory or an optical memory. A semiconductor memory is, for example, a RAM or a ROM. "RAM" is an abbreviation for random access memory. "ROM" is an abbreviation for read only memory. RAM is, for example, SRAM or DRAM. "SRAM" is an abbreviation for static random access memory. "DRAM" is an abbreviation for dynamic random access memory. ROM is, for example, EEPROM. "EEPROM" is an abbreviation for electrically erasable programmable read only memory. The memory functions, for example, as main memory, auxiliary memory, or cache memory. Information used for the operation of the communication device 20 and information obtained by the operation of the communication device 20 are stored in the storage unit 22 .

The communication unit 23 is one or more communication ICs. "IC" is an abbreviation for integrated circuit. The communication IC is, for example, a wireless communication IC compatible with a cellular wireless system such as LTE Cat-M1. "LTE Cat-M1" is an abbreviation for Long Term Evolution, category M1. The communication unit 23 receives information used for the operation of the communication device 20 from the management device 30 via the network 40 and transmits information obtained by the operation of the communication device 20 to the management device 30 via the network 40 . That is, the communication unit 23 communicates with the management device 30 .

The positioning unit 24 is one or more positioning ICs. The positioning IC is, for example, a satellite positioning IC compatible with GNSS, or a radio communication IC common to the communication unit 23, compatible with the base station positioning method. "GNSS" is an abbreviation for global navigation satellite system. GNSS includes at least one of GPS, QZSS, GLONASS, and Galileo, for example. "GPS" is an abbreviation for Global Positioning System. "QZSS" is an abbreviation for Quasi-Zenith Satellite System. The QZSS satellites are called quasi-zenith satellites. "GLONASS" is an abbreviation for Global Navigation Satellite System. The positioning unit 24 measures the position of the communication device 20 .

The sound detection unit 25 detects sounds around the communication device 20 . As shown in FIG. 3, the sound detection unit 25 includes a microphone 51, a bandpass filter 52, a comparator 53, and a noise filter . A microphone 51 inputs sound to a bandpass filter 52 . The bandpass filter 52 attenuates sounds other than a specific frequency. The comparator 53 outputs a signal to the noise filter 54 when the loudness of the sound input from the bandpass filter 52 is equal to or greater than a certain threshold value T1. A noise filter 54 removes noise. The sound detection unit 25 is always energized in modes other than the power-off mode, but power is saved by using passive components and ultra-low consumption components.

The acceleration sensor 26 measures acceleration of the communication device 20 .

Battery 27 may be a primary battery or a secondary battery. Battery 27 is used as a power source for communication device 20 .

The functions of the communication device 20 are implemented by executing the communication program according to the present embodiment with a processor included in the control unit 21 . That is, the functions of the communication device 20 are realized by software. The communication program is a program for causing a computer to execute a step process included in the operation of the communication device 20, thereby causing the computer to implement a function corresponding to the step process. That is, the communication program is a program for causing the computer to function as the communication device 20 .

The program can be recorded in a computer-readable recording medium. A computer-readable recording medium is, for example, a magnetic recording device, an optical disk, a magneto-optical recording medium, or a semiconductor memory. Program distribution is performed, for example, by selling, assigning, or lending a portable recording medium such as a DVD or CD-ROM on which the program is recorded. "DVD" is an abbreviation for digital versatile disc. "CD-ROM" is an abbreviation for compact disc read only memory. The program may be distributed by storing the program in the storage of the server and transferring the program from the server to another computer via the network 40 . A program may be provided as a program product.

The computer, for example, once stores in memory a program recorded on a portable recording medium or a program transferred from a server. Then, the computer reads the program stored in the memory with the processor, and executes processing according to the read program with the processor. The computer may read the program directly from the portable recording medium and execute processing according to the program. The computer may execute processing according to the received program every time the program is transferred from the server to the computer. The processing may be executed by a so-called ASP type service that realizes the function only by executing the execution instruction and obtaining the result without transferring the program from the server to the computer. "ASP" is an abbreviation for application service provider. The program includes information that is used for processing by a computer and that conforms to the program. For example, data that is not a direct instruction to a computer but that has the property of prescribing the processing of the computer corresponds to "things equivalent to a program."

A part or all of the functions of the communication device 20 may be implemented by a dedicated circuit included in the control section 21 . That is, part or all of the functions of the communication device 20 may be realized by hardware.

The configuration of the management device 30 according to this embodiment will be described with reference to FIG.

The management device 30 includes a control section 31 , a storage section 32 and a communication section 33 .

The controller 31 is one or more processors. A processor may be a general-purpose processor, such as a CPU, or a dedicated processor specialized for a particular process. The controller 31 may include one or more dedicated circuits, or one or more processors may be replaced with one or more dedicated circuits in the controller 31 . A dedicated circuit is, for example, an FPGA or an ASIC. The control unit 31 executes information processing related to the operation of the management device 30 while controlling each unit of the management device 30 .

The storage unit 32 is one or more memories. The memory is for example a semiconductor memory, a magnetic memory or an optical memory. A semiconductor memory is, for example, a RAM or a ROM. RAM is, for example, SRAM or DRAM. ROM is, for example, EEPROM. The memory functions, for example, as main memory, auxiliary memory, or cache memory. The storage unit 32 stores information used for the operation of the management device 30 and information obtained by the operation of the management device 30 .

The communication unit 33 is one or more communication ICs. The communication IC is, for example, a LAN communication IC. "LAN" is an abbreviation for local area network. The communication unit 33 receives information used for the operation of the management device 30 from the communication device 20 via the network 40 and transmits information obtained by the operation of the management device 30 to the communication device 20 via the network 40 . That is, the communication unit 33 communicates with multiple communication devices 20 .

The functions of the management device 30 are realized by executing the management program according to the present embodiment with a processor included in the control unit 31 . That is, the functions of the management device 30 are realized by software. The management program is a program for causing a computer to execute a step process included in the operation of the management device 30, thereby causing the computer to implement a function corresponding to the step process. That is, the management program is a program for causing the computer to function as the management device 30. FIG.

A part or all of the functions of the management device 30 may be realized by a dedicated circuit included in the control section 31 . That is, part or all of the functions of the management device 30 may be implemented by hardware.

The operation of the communication device 20 according to this embodiment will be described with reference to FIG. The operation of the communication device 20 or the operation of the communication system 10 including the associated operation of the management device 30 corresponds to the communication method according to this embodiment.

In step S101, the communication device 20 transitions from the power off mode to the low power consumption mode by a power-on operation such as pressing a power key. The power-on operation is performed before or immediately after the cargo 11 to which the communication device 20 is attached is loaded onto the vessel 12 .

In step S102, the sound detection unit 25 detects sound. When the sound detecting unit 25 detects a sound that satisfies at least part of the requirements for the whistle, the control unit 21 is activated in step S103. When the control unit 21 is activated, the communication device 20 transitions from the low power consumption mode to the operating mode. Then, the flow proceeds to step S104.

Specifically, the microphone 51 picks up sound, the sound of a specific frequency passes through the bandpass filter 52, and the comparator 53 outputs a signal when the sound pressure is equal to or greater than the threshold value T1. Since noise having the same or similar frequency and sound pressure as the whistle may occur momentarily, the noise filter 54 ANDs the output of the delay circuit to remove the noise. A processor such as a CPU included in the control unit 21 is activated by the noise-removed signal.

In step S<b>104 , the control unit 21 determines whether the sound detected by the sound detection unit 25 in step S<b>102 is the whistle of the ship 12 . When the control unit 21 determines that the sound detected by the sound detection unit 25 is a whistle, the positioning unit 24 measures the position in step S105. Then, the flow proceeds to step S106. On the other hand, when the control unit 21 determines that the sound detected by the sound detection unit 25 is not the whistle, the control unit 21 stops again. When the control unit 21 stops, the communication device 20 transitions from the operating mode to the low power consumption mode. The flow then returns to step S102.

Specifically, a processor such as a CPU included in the control unit 21 analyzes whether or not the frequency and ringing interval of the emitted sound are as stipulated by laws such as Japan's Maritime Collision Prevention Law Enforcement Regulations. If all of the whistle's requirements, such as frequency and ring interval, are met, the positioning component 24 uses satellite or base station information to perform positioning. It should be noted that "all the requirements for the whistle are satisfied" does not necessarily mean that all the physical quantities to be analyzed meet the conditions. If more types of physical quantities than "at least part of the requirements for the whistle" in step S102 among the physical quantities to be analyzed match the conditions, the control unit 21 determines that "all the requirements for the whistle are satisfied." It may be determined that

In step S106, the control unit 21 determines whether the ship 12 is moving on the ocean based on the positioning result of the positioning unit 24 in step S105. That is, the control unit 21 determines whether the ship 12 has left the port 13 or not. When the control unit 21 determines that the vessel 12 is moving on the ocean, the control unit 21 selects the ocean mode in step S107. When the controller 21 selects the ocean mode, the communication device 20 transitions from the operating mode to the ocean mode. Then, the flow proceeds to step S108. On the other hand, when the control unit 21 determines that the vessel 12 is not moving on the ocean, the control unit 21 stops again. When the control unit 21 stops, the communication device 20 transitions from the operating mode to the low power consumption mode. The flow then returns to step S102.

Specifically, a processor such as a CPU included in the control unit 21 determines whether the coordinates of the position measured by the positioning unit 24 are included in the coordinate range of the sea area excluding the harbor 13, which is stored in the storage unit 22 in advance. It is determined whether the vessel 12 is away from the port 13 by determining whether. It may be determined whether the ship 12 is away from the port 13 not only from the coordinates of one point but also from the trajectory of the coordinates of a plurality of points. If vessel 12 is away from port 13, processor initiates intermittent operation in marine mode. If vessel 12 has not left port 13, either vessel 12 has blown the whistle but has not left port 13, or another vessel has blown the whistle.

In the ocean mode, the control unit 21 may perform control to suppress consumption of the battery 27, such as not performing transmission in a place clearly out of the communication range away from land. For example, the control unit 21 determines whether the coordinates of the position measured by the positioning unit 24 are included in the coordinate range of the communication area, which is stored in advance in the storage unit 22, so that the current position is out of the communication area. determine whether there is In the case of international transport, the control unit 21 may perform roaming settings for the expected arrival point when approaching land to prevent unnecessary radio wave searches.

In step S108, the control unit 21 controls the communication unit 23 to notify the management device 30 of the position on the sea measured by the positioning unit 24 as control in the ocean mode until a completion factor occurs. Each time this control is performed, the communication unit 23 notifies the management device 30 of the position on the ocean measured by the positioning unit 24 . A completion factor occurs, for example, when the vessel 12 arrives at a predesignated position or when the management device 30 instructs completion. When a completion factor occurs, the communication device 20 transitions from the ocean mode to the low power consumption mode or the power off mode.

In order to cope with the case where the ship 12 leaves the port 13 without sounding the whistle, a processor such as a CPU included in the control unit 21 is activated by an interrupt from the acceleration sensor 26 separately from the processing of steps S102 to S104. It may operate and the processing after step S105 may be performed.

As described above, in the present embodiment, the control unit 21 of the communication device 20 determines whether the sound detected by the sound detection unit 25 is the whistle of the ship 12 . The control unit 21 selects one of the ocean mode and the low power consumption mode according to the determination result and the positioning result of the positioning unit 24 . The offshore mode is a mode in which the control unit 21 performs control to notify the management device 30 of the offshore position measured by the positioning unit 24 from the communication unit 23 . The low power consumption mode is a mode in which the control unit 21 does not perform the control. That is, the offshore mode is a mode in which processing for notifying the management device 30 of the position on the ocean measured by the communication device 20 is performed. The low power consumption mode is a mode in which the communication device 20 does not perform the processing. The communication device 20 transitions to the mode selected by the control unit 21 . Therefore, according to this embodiment, the power consumption of the communication device 20 attached to the cargo 11 for tracking the cargo 11 transported by the ship 12 can be reduced. Further, according to the present embodiment, slow motion of the ship 12 that cannot be detected by the acceleration sensor 26 can be detected by sound.

In this embodiment, the control unit 21 is stopped in the low power consumption mode. Therefore, according to this embodiment, the power consumption before starting tracking can be significantly reduced.

In this embodiment, the control unit 21 selects the offshore mode when determining that the sound detected by the sound detection unit 25 is a whistle and the ship 12 is moving on the offshore. Therefore, according to the present embodiment, if the ship 12 has sounded the whistle but has not left the port 13, or if another ship has sounded the whistle, it is erroneously determined that the ship 12 has left the port 13. easier to avoid. Further, according to this embodiment, the consumption of the battery 27 can be suppressed by keeping the communication device 20 in the low power consumption mode until the ship 12 leaves the port 13 .

In this embodiment, the communication device 20 does not have to include the acceleration sensor 26 .

A first modified example, which is a modified example of the present embodiment, will be described below.

In this modified example, modes of the communication device 20 include an operation mode, an ocean mode, a low power consumption mode, and a power off mode, as well as a land mode. The land mode is a mode in which the communication device 20 intermittently performs positioning while moving on land and transmits position information to the management device 30 .

In the ocean mode, at least one of the positioning interval and the number of retransmissions when out of service area may be changed from those in the land mode. For example, in ocean mode, the positioning interval may be longer than in land mode. For example, in ocean mode, the number of retransmissions when out of service may be less than in land mode.

In this modification, when there is an interruption by the acceleration sensor 26 during the ocean mode, the communication device 20 recognizes that the cargo 11 has been landed, and transitions to the land mode. Then, it is assumed that an erroneous recognition has occurred, and the mode is changed again to the ocean mode. For example, when a sudden wave change occurs on the ocean, an interruption by the acceleration sensor 26 may occur.

The operation of the communication device 20 according to this modification will be described with reference to FIG.

Since the processing from step S201 to step S207 is the same as the processing from step S101 to step S107, description thereof is omitted.

In step S208, the acceleration sensor 26 measures acceleration. If the acceleration sensor 26 measures the acceleration exceeding the threshold T2, the controller 21 selects the land mode in step S209. When the control unit 21 selects the land mode, the communication device 20 transitions from the ocean mode to the land mode. Flow then proceeds to step S210.

Specifically, when the acceleration sensor 26 measures acceleration exceeding the threshold value T2, a processor such as a CPU included in the control unit 21 operates due to an interrupt from the acceleration sensor 26, and determines whether the cargo 11 has actually been landed. Perform processing for confirmation.

In step S210, the positioning unit 24 measures the position. The control unit 21 determines whether the ship 12 is moving on the ocean based on the positioning result obtained by the positioning unit 24 . That is, the control unit 21 determines whether the cargo 11 has actually been landed. When the control unit 21 determines that the ship 12 is moving on the ocean, the control unit 21 selects the ocean mode in step S207. When the controller 21 selects the ocean mode, the communication device 20 transitions from the land mode to the ocean mode again.

Specifically, a processor such as a CPU included in the control unit 21 determines whether or not the coordinates of the position measured by the positioning unit 24 are included in the coordinate range of the sea area pre-stored in the storage unit 22. , it is determined whether the vessel 12 is still moving over the ocean. If the vessel 12 is moving over the ocean, the processor resumes the ocean mode intermittent operation. If the vessel 12 is not moving over the ocean, the processor initiates land mode intermittent operation.

In step S<b>211 , the control unit 21 performs control for notifying the management device 30 of the position on land measured by the positioning unit 24 from the communication unit 23 as control in the land mode until the vehicle stops on land. Each time this control is performed, the communication unit 23 notifies the management device 30 of the position on land measured by the positioning unit 24 . It is determined from the result of positioning by the positioning unit 24 whether the cargo 11 is placed on a mobile object such as a vehicle and is moving on land. When the control unit 21 determines that the moving body carrying the cargo 11 is not moving on land, the control unit 21 stops in step S212. When the control unit 21 stops, the communication device 20 transitions from the land mode to the low power consumption mode.

Specifically, a processor such as a CPU included in the control unit 21 determines whether or not the coordinates of the position measured by the positioning unit 24 change over time, thereby determining whether the moving body carrying the cargo 11 is moving on land. If the mobile object carrying cargo 11 is moving on land, the processor continues intermittent operation in the land mode. If the vehicle carrying cargo 11 is not moving over land, the processor terminates the land mode intermittent operation.

In step S213, the acceleration sensor 26 measures acceleration. When the acceleration sensor 26 measures the acceleration exceeding the threshold T3, the controller 21 selects the land mode in step S214. The threshold T3 may be the same value as the threshold T2. When the control unit 21 selects the land mode, the communication device 20 transitions from the ocean mode to the land mode. The flow then proceeds to step S215.

Specifically, when the acceleration sensor 26 measures acceleration exceeding the threshold value T3, a processor such as a CPU included in the control unit 21 resumes intermittent operation in the land mode due to an interrupt from the acceleration sensor 26 .

In step S<b>215 , the control unit 21 performs control for notifying the management device 30 of the land position measured by the positioning unit 24 from the communication unit 23 as control in the land mode until a completion factor occurs. Each time this control is performed, the communication unit 23 notifies the management device 30 of the position on land measured by the positioning unit 24 . The flow then returns to step S211. The completion factor occurs, for example, when the moving body carrying the cargo 11 arrives at a predesignated position, or when the management device 30 instructs completion. The communication device 20 transitions from the land mode to the low power consumption mode or the power off mode when a completion factor occurs.

The processing from step S202 to step S211 may be set to be valid only when the transportation method of the cargo 11 is by sea, by an operation such as switching of a slide switch. When the processing from step S202 to step S211 is disabled, the sound detection unit 25 is turned off.

According to this modification, the consumption of the battery 27 can be suppressed by setting an operation mode specific to marine transportation in addition to the operation mode for land transportation.

A second modified example, which is a further modified example of the first modified example, will be described below.

If a plurality of communication devices 20 are in approximately the same position and are in ocean mode, it can be assumed that they are all moving on the same vessel 12 . Therefore, in this modification, the management device 30 selects the representative communication device 20 and causes the other communication devices 20 to transition to the low power consumption mode, thereby preventing unnecessary consumption of the battery 27 . The management device 30 may select one of the representative communication devices 20 with the highest remaining battery 27 , or may select several of them.

Specifically, in the management device 30, the control unit 31 determines that the plurality of communication devices 20 are in the ocean mode, and that the communication unit 33 is notified immediately after the transition from the plurality of communication devices 20 to the ocean mode in step S207. When the difference between the positions is equal to or less than a specified value, the second communication device other than the first communication device, which is at least one of the plurality of communication devices 20, of the plurality of communication devices 20 is reduced in consumption via the communication unit 33. Transition to power mode. As an example, if the communication device A1 shown in FIG. 1 is selected as the representative communication device 20, the communication device A1 corresponds to the first communication device, and the communication devices A2, A3, and A4 are the second communication devices. Corresponds to a communication device. The “specified value” is predetermined according to the size of the ship 12 .

In this modification, the management device 30 makes it possible for the representative communication device 20 to return to land even if the communication device 20 that has been forcibly transitioned to the low power consumption mode is restarted due to the interruption of the whistle or the acceleration sensor 26. Until it approaches, the rest of the communication devices 20 are repeatedly switched to the low power consumption mode.

Specifically, in the management device 30, the control unit 31 controls the second communication device when any one of the communication device A2, the communication device A3, and the communication device A4 transitions to the ocean mode in step S207. Transition the device to a low power consumption mode.

In this modification, when a non-representative communication device 20 transitions to the land mode due to landing, the management device 30 substitutes the tracking information of the representative communication device 20 for the tracking information in the low power consumption mode.

Specifically, in the management device 30, the control unit 31 stores the history of the position notified from the communication device A1 in the storage unit 32. FIG. When any of the second communication devices of the communication device A2, the communication device A3, and the communication device A4 transitions to the land mode, the control unit 31 stores the history stored in the storage unit 32 in the offshore communication device of the second communication device. Use as location history.

According to this modification, when a plurality of communication devices 20 are on the same ship 12, it is possible to suppress the consumption of the battery 27 by switching the communication devices 20 other than the representative to the low power consumption mode.

The disclosure is not limited to the embodiments described above. For example, multiple blocks depicted in the block diagrams may be integrated or one block may be divided. Instead of executing the steps described in the flowchart in chronological order according to the description, the steps may be executed in parallel or in a different order depending on the processing power of the device executing each step or as required. Other modifications are possible without departing from the scope of the present disclosure.

10 communication system 11 cargo 12 ship 13 port 20 communication device 21 control unit 22 storage unit 23 communication unit 24 positioning unit 25 sound detection unit 26 acceleration sensor 27 battery 30 management device 31 control unit 32 storage unit 33 communication unit 40 network 51 microphone 52 Bandpass filter 53 Comparator 54 Noise filter

Claims (10)

In communication equipment used attached to cargo,
a sound detection unit that detects sound;
a positioning unit that measures a position;
a communication unit that communicates with the management device;
determining whether or not the sound detected by the sound detection unit is the whistle of a ship, and determining the position on the ocean measured by the positioning unit according to the result of the determination and the result of positioning by the positioning unit; A communication device comprising a control unit that selects one of an offshore mode that performs control for notification from the communication unit to the management device and a low power consumption mode that does not perform the control. 2. The communication device according to claim 1, wherein the control unit is activated when a sound that satisfies at least part of the requirements of the whistle is detected by the sound detection unit. 3. The communication device according to claim 1, wherein said control unit is stopped in said low power consumption mode. The control unit determines whether the ship is moving on the sea based on the positioning result, the sound detected by the sound detection unit is the whistle, and the ship is moving on the sea. 4. The communication device according to any one of claims 1 to 3, wherein the ocean mode is selected when it is determined that. It also has an acceleration sensor that measures acceleration,
In the offshore mode, when the acceleration sensor measures an acceleration exceeding a threshold value, the control unit performs control to notify the management device of the position on land measured by the positioning unit from the communication unit. 5. A communication device as claimed in any one of claims 1 to 4 for selecting modes. a plurality of communication devices each being a communication device according to any one of claims 1 to 4;
When the plurality of communication devices are in the ocean mode and the difference in position notified from the plurality of communication devices is equal to or less than a specified value, at least one communication device among the plurality of communication devices and a management device that causes second communication devices other than the first communication device to transition to the low power consumption mode. The communication system according to claim 6, wherein the management device causes the second communication device to transition to the low power consumption mode when the second communication device transitions to the ocean mode. When the second communication device measures an acceleration exceeding a threshold value in the low power consumption mode, the second communication device transitions to a land mode for notifying the management device of the measured position on land,
The management device stores the history of the position notified from the first communication device, and stores the stored history of the position on the ocean of the second communication device when the second communication device transitions to the land mode. 8. The communication system according to claim 6 or 7, which is used as a history. A communication device attached to cargo detects sound, determines whether the detected sound is a ship's whistle, and manages the measured position on the ocean according to the result of the determination and the result of positioning. A communication method that selects one of an ocean mode in which processing to notify a device and a low power consumption mode in which the processing is not performed, and transitions to the selected mode. A communication device attached to cargo detects sound, determines whether the detected sound is a ship's whistle, and manages the measured position on the sea according to the result of the determination and the result of positioning. A program for selecting one of a marine mode in which processing to notify the apparatus and a low power consumption mode in which the processing is not performed, and transitioning to the selected mode.

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