Remote monitoring system, wireless communication device, server, and remote monitoring method

Abstract

A wireless communication device (3) comprises an operation information acquisition unit (300) that acquires operation information from an air conditioner, a timestamp assignment unit (301) that assigns timestamps to the acquired operation information, a time synchronization unit (305) that acquires time information indicating the current time from a time server by communication using a cellular communication line, a timestamp correction unit (306) that, when the time information is acquired by the time synchronization unit (305), corrects the timestamps of all operation information acquired from the air conditioner within a period since activation thereof until acquisition of the time information, and a correction completion notification unit (307) that, upon completion of correction of the timestamps of all the relevant operation information by the timestamp correction unit (306), transmits a timestamp correction completion notification to a remote monitoring server by communication using the cellular communication line. The present invention can thereby enhance maintenance services.

Description

Remote monitoring system, wireless communication device, server, and remote monitoring method

[0001] The present disclosure relates to a remote monitoring system, a wireless communication device, a server, and a remote monitoring method.

[0002] A service is known in which a wireless communication device connected to an air conditioner by wire periodically acquires the operation information of the air conditioner, adds a timestamp to the acquired operation information, and uploads the uploaded operation information to a remote monitoring server, where it is used for maintenance of the air conditioner. In addition, technology that employs a cellular system for communication between the wireless communication device and the remote monitoring server in such services is attracting attention.

[0003] Because such services often require intermittent use, service providers may leave wireless communication devices installed and stop providing the service at the request of users (e.g., building owners). In cellular communications, a basic fee (calculated pro rata) based on the validity period of the cellular communication line is typically charged in addition to fees based on the actual usage of the cellular communication line. Therefore, service providers typically disable the cellular communication line in the wireless communication device while the service is stopped.

[0004] On the other hand, the service provider may wish to improve the service by reflecting the operation information of the air conditioners during the suspension period after the service is resumed, thereby recommending maintenance and replacement. In this case, the wireless communication device may periodically acquire operation information from the air conditioners even during the suspension of service, store it in an internal storage device, and then upload the stored operation information to the remote monitoring server when the service is resumed.

[0005] This type of wireless communication device typically receives power from the air conditioner to which it is connected. Therefore, if the power supply to the air conditioner is interrupted due to a planned shutdown of the air conditioner or a power outage, the power supply to the wireless communication device will also be interrupted. When power is subsequently supplied to the air conditioner due to a restart of operation or restoration of power transmission, power is also supplied to the wireless communication device, and the wireless communication device resumes periodically obtaining operating information. At this time, if its own cellular communication line is active, the wireless communication device can immediately obtain time information from a time server and assign an accurate timestamp to the operating information obtained from the air conditioner.

[0006] However, as described above, during service outages, the cellular communication line is disabled, so the wireless communication device cannot obtain time information from the time server and cannot assign an accurate timestamp to the operation information obtained from the air conditioner. As a result, there is a problem in that the operation information obtained during service outages cannot be effectively utilized.

[0007] One possible solution to the above problem is to incorporate a power source such as a large-capacity electrolytic capacitor or secondary battery into the wireless communication device, so that if the external power supply is cut off, the power supplied from the power source can be used to maintain timekeeping using an RTC (Real-Time Clock) (see, for example, Patent Document 1).

[0008] Japanese Patent Application Laid-Open No. 2002-16987

[0009] However, providing a large-capacity power supply poses another problem of increased costs. For this reason, there is a need for a new technology that can provide accurate timestamps to operational information obtained from air conditioners, regardless of whether the remote monitoring service is running.

[0010] The present disclosure has been made in consideration of the above-mentioned situation, and aims to provide a remote monitoring system, wireless communication device, server, and remote monitoring method that are capable of assigning an accurate timestamp to operating information obtained from an air conditioner without incurring an increase in costs.

[0011] In order to achieve the above object, the remote monitoring system according to the present disclosure comprises a server and a wireless communication device, wherein the server comprises: a communication line enabling means for periodically enabling a cellular communication line of the wireless communication device while a remote monitoring service is stopped; and a communication line disabling means for disabling the cellular communication line while the remote monitoring service is stopped, upon receiving a timestamp correction completion notification from the wireless communication device indicating that timestamp correction has been completed; and the wireless communication device comprises: an operating information acquiring means for acquiring operating information from an air conditioner; a timestamp assigning means for assigning a timestamp to the acquired operating information; a time synchronization means for acquiring time information indicating the current time from a time information providing means by communication using the cellular communication line; a timestamp correction means for correcting timestamps of all operating information acquired from the air conditioner from the time of startup until the time information is acquired, when the timestamp correction means has completed correction of timestamps of all operating information.

[0012] According to the present disclosure, it is possible to assign an accurate timestamp to operating information obtained from an air conditioner without increasing costs.

[0013] FIG. 1 is a diagram showing the overall configuration of a remote monitoring system in an embodiment; BLOCK DIAGRAM showing the hardware configuration of a wireless communication device in an embodiment; BLOCK DIAGRAM showing the hardware configuration of a remote monitoring server in an embodiment; FIG. 1 is a diagram showing the functional configuration of a wireless communication device in an embodiment; BLOCK DIAGRAM showing the functional configuration of a remote monitoring server in an embodiment; A flowchart showing the operation flow of a remote monitoring server when the remote monitoring service is stopped in an embodiment; A flowchart showing the operation flow of a wireless communication device when the remote monitoring service is stopped in an embodiment; A diagram showing the communication sequence of a remote monitoring system when the remote monitoring service is stopped in an embodiment.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0015] 1 is a diagram showing the overall configuration of a remote monitoring system 1 according to an embodiment. The remote monitoring system 1 is an example of a remote monitoring system according to the present disclosure. The remote monitoring system 1 is a system that monitors the equipment status of air conditioners 2 installed in buildings such as office buildings and commercial buildings, and provides services such as maintenance and replacement recommendations for the air conditioners 2 (hereinafter referred to as "remote monitoring services") to the owners of the buildings, and includes the air conditioners 2, a wireless communication device 3, a remote monitoring server 4, and a time server 5.

[0016] <Air Conditioner 2> The air conditioner 2 is an example of an air conditioner according to the present disclosure. The air conditioner 2 includes an outdoor unit installed outdoors and one or more indoor units installed indoors, and provides air conditioning for the building. The outdoor unit is communicably connected to the wireless communication device 3 via a communication line 6, and transmits operating information relating to its own operation to the wireless communication device 3 in response to a request from the wireless communication device 3. The operating information includes, for example, measurement results from various sensors equipped in the outdoor unit and each indoor unit.

[0017] <Wireless Communication Device 3> The wireless communication device 3 is an example of a wireless communication device according to the present disclosure. The wireless communication device 3 is installed outdoors, is communicatively connected to the outdoor unit of the air conditioner 2 via a communication line 6, and receives power from the outdoor unit via the communication line 6. The wireless communication device 3 periodically acquires operating information from the air conditioner 2, and, when a remote monitoring service is running, transmits a log of the acquired operating information to the remote monitoring server 4.

[0018] 2, the wireless communication device 3 includes, as its hardware configuration, a first communication interface 30, a second communication interface 31, a CPU (Central Processing Unit) 32, a ROM (Read-Only Memory) 33, a RAM (Random-Access Memory) 34, and an auxiliary storage device 35. These components are connected to each other via a bus 36.

[0019] The first communication interface 30 is hardware for communicating with the air conditioner 2 via the communication line 6. The second communication interface 31 is hardware for wireless communication with the remote monitoring server 4 and the time server 5. In this embodiment, the wireless communication device 3 communicates with the remote monitoring server 4 and the time server 5 using a cellular system (e.g., LTE (Long-Term Evolution), LPWA (Low Power Wide Area), etc.). The remote monitoring server 4 switches between enabling and disabling the cellular communication line of the wireless communication device 3.

[0020] The CPU 32 performs overall control of the wireless communication device 3. Details of the functions of the wireless communication device 3 realized by the CPU 32 will be described later. The ROM 33 stores multiple pieces of firmware and data used when these firmware are executed. The RAM 34 is used as a work area for the CPU 32.

[0021] The auxiliary storage device 35 is configured with a readable / writable nonvolatile semiconductor memory, a hard disk drive (HDD), etc. Examples of the readable / writable nonvolatile semiconductor memory include an electrically erasable programmable read-only memory (EEPROM), a flash memory, etc. The auxiliary storage device 35 stores a wireless communication device program, which is a program for realizing each function of the wireless communication device 3 described below, and data used when the wireless communication device program is executed.

[0022] The wireless communication device 3 can acquire a wireless communication device program or an update program for updating the wireless communication device program from the remote monitoring server 4 or another server via communication using a cellular communication line. These programs can also be stored and distributed on a computer-readable recording medium such as a CD-ROM (Compact Disc Read-Only Memory), a DVD (Digital Versatile Disc), a magneto-optical disk, a USB (Universal Serial Bus) memory, a HDD (HDD), a SSD (Solid-State Drive), or a memory card. When such a recording medium is directly or indirectly attached to the wireless communication device 3, the wireless communication device 3 can read the wireless communication device program or update program from the recording medium and install it on itself.

[0023] <Remote monitoring server 4> The remote monitoring server 4 is an example of a server according to the present disclosure. The remote monitoring server 4 is installed in a location different from the building in which the air conditioner 2 is installed, and is a server computer that monitors the device status of the air conditioner 2. As shown in Fig. 3, the remote monitoring server 4 includes, as hardware components, a communication interface 40, a CPU 41, a ROM 42, a RAM 43, and an auxiliary storage device 44. These components are connected to each other via a bus 45.

[0024] The communication interface 40 is hardware for wireless communication with the wireless communication device 3. In this embodiment, the remote monitoring server 4 communicates with the wireless communication device 3 using a cellular system (e.g., LTE, LPWA, etc.). The CPU 41 comprehensively controls the remote monitoring server 4. Details of the functions of the remote monitoring server 4 realized by the CPU 41 will be described later. The ROM 42 stores multiple pieces of firmware and data used when these pieces of firmware are executed. The RAM 43 is used as a work area for the CPU 41.

[0025] The auxiliary storage device 44 is composed of a readable / writable nonvolatile semiconductor memory, a HDD, etc. Examples of the readable / writable nonvolatile semiconductor memory include an EEPROM, a flash memory, etc. The auxiliary storage device 44 stores a remote monitoring program, which is a program for realizing each function of the remote monitoring server 4 described below, and data used when the remote monitoring program is executed.

[0026] The remote monitoring server 4 can acquire the remote monitoring program or an update program for updating the remote monitoring program from another server via communication. These programs can also be stored and distributed on a computer-readable recording medium such as a CD-ROM, DVD, optical magnetic disk, USB memory, HDD, SSD, or memory card. When such a recording medium is directly or indirectly attached to the remote monitoring server 4, the remote monitoring server 4 can read the remote monitoring program or update program from the recording medium and install it on itself.

[0027] <Time Server 5> The time server 5 is an example of a time information providing unit according to the present disclosure. The time server 5 is a server computer that distributes time information indicating the correct time.

[0028] 4 , the wireless communication device 3 includes, as functional components, a driving information acquisition unit 300, a time stamp assignment unit 301, a time management unit 302, a transmission enable / disable switching unit 303, a driving information log transmission unit 304, a time synchronization unit 305, a time stamp correction unit 306, and a correction completion notification unit 307. These functional units are realized by the CPU 32 executing the above-mentioned wireless communication device program stored in the auxiliary storage device 35.

[0029] The operation information acquisition unit 300 is an example of an operation information acquisition means according to the present disclosure. The operation information acquisition unit 300 periodically (for example, every minute) acquires operation information from the air conditioner 2. Specifically, the operation information acquisition unit 300 periodically transmits a command to the air conditioner 2 via the communication line 6, requesting the transmission of operation information. Upon receiving the command, the air conditioner 2 transmits operation information including measurement results of various sensors provided in the outdoor unit and each indoor unit constituting the air conditioner 2 to the wireless communication device 3 via the communication line 6. The operation information acquisition unit 300 receives and acquires the operation information sent from the air conditioner 2, and stores the acquired operation information in the auxiliary storage device 35.

[0030] The timestamp assigning unit 301 is an example of a timestamp assigning means according to the present disclosure. The timestamp assigning unit 301 assigns a timestamp based on the current time (specifically, the current year, month, date, hour, and minute) managed by the time management unit 302 to the driving information acquired by the driving information acquisition unit 300. At this time, the timestamp assigning unit 301 refers to a time synchronization flag, and if the time synchronization flag is OFF, the timestamp assigning unit 301 further assigns information indicating that the timestamp is a provisional time that is not accurate (hereinafter referred to as "provisional time information") to the driving information. The time synchronization flag is a variable that is cleared (i.e., set to OFF) when the wireless communication device 3 is started up and set to ON when time synchronization is completed by the time synchronization unit 305 (described later), and is stored in the RAM 34 or the auxiliary storage device 35.

[0031] The time management unit 302 manages the current time based on the time indicated by the time information acquired from the time server 5 by the time synchronization unit 305 and the timer function of the CPU 32. However, the current time managed by the time management unit 302 is not accurate from the time when power supply to the wireless communication device 3 starts (i.e., from the time when the wireless communication device 3 starts) until time synchronization is completed by the time synchronization unit 305, that is, while the time synchronization flag is OFF.

[0032] The transmission enable / disable switching unit 303 is an example of a transmission enabling means according to the present disclosure. When the transmission enable / disable switching unit 303 receives a notification from the remote monitoring server 4 instructing to enable transmission using the cellular communication line, the transmission enable / disable switching unit 303 enables transmission using the cellular communication line. Specifically, the transmission enable / disable switching unit 303 sets a transmission enable flag to ON. Furthermore, when the transmission enable / disable switching unit 303 receives a notification from the remote monitoring server 4 instructing to disable transmission using the cellular communication line, the transmission enable / disable switching unit 303 disables transmission using the cellular communication line. Specifically, the transmission enable flag is set to OFF. The transmission enable flag is a variable indicating whether transmission using the cellular communication line of the wireless communication device 3 is enabled or disabled, and is stored in the auxiliary storage device 35. Note that the transmission enable / disable switching unit 303 may autonomously set the transmission enable flag to OFF when time synchronization is completed by the time synchronization unit 305 while the remote monitoring service is stopped.

[0033] When the transmission enable flag is ON and the service enable flag is ON, the operating information log transmission unit 304 periodically (for example, every 10 minutes) transmits the operating information log stored in the auxiliary storage device 35 to the remote monitoring server 4 via communication using a cellular communication line. The service enable flag is a variable that indicates whether the remote monitoring service for the air conditioner 2 is enabled or disabled, and is stored in the auxiliary storage device 35. When the remote monitoring service for the air conditioner 2 is enabled, the service enable flag is set to ON, and when the remote monitoring service for the air conditioner 2 is not enabled, the service enable flag is set to OFF. The service enable flag is switched ON / OFF by a notification from the remote monitoring server 4.

[0034] In addition, when the service enable flag is switched from OFF to ON, the driving information log transmission unit 304 may transmit the driving information logs stored in the auxiliary storage device 35, which were acquired while the remote monitoring service was stopped, all at once to the remote monitoring server 4, or may transmit them together with the driving information logs that are divided and transmitted periodically.

[0035] The time synchronization unit 305 is an example of a time synchronization means according to the present disclosure. After the wireless communication device 3 is started, when the transmission enable flag is turned ON, the time synchronization unit 305 accesses the time server 5 via communication using a cellular communication line and acquires time information indicating the current time. The time synchronization unit 305 updates the current time managed by the time management unit 302 based on the acquired time information. This completes time synchronization. When time synchronization is completed, the time synchronization unit 305 switches the time synchronization flag to ON.

[0036] The timestamp correction unit 306 is an example of a timestamp correction means according to the present disclosure. When the time synchronization flag is switched ON, the timestamp correction unit 306 corrects the timestamps of all driving information stored in the auxiliary storage device 35 that has provisional time information attached thereto, based on the current time managed by the time management unit 302. The timestamp correction unit 306 removes the provisional time information from the driving information for which the timestamp correction has been completed.

[0037] The correction completion notification unit 307 is an example of a correction completion notification means according to the present disclosure. When the timestamp correction unit 306 completes the correction of the timestamps of all the target driving information, the correction completion notification unit 307 transmits a timestamp correction completion notification indicating that the timestamp correction has been completed to the remote monitoring server 4 via communication using a cellular communication line.

[0038] 5, the remote monitoring server 4 has, as its functional configuration, an operation information log acquisition unit 400, a communication line activation unit 401, a communication line deactivation unit 402, a transmission enable / disable switching instruction unit 403, a service start notification unit 404, and a service stop notification unit 405. These functional units are realized by the CPU 41 executing the above-mentioned remote monitoring program stored in the auxiliary storage device 44. In addition to these, the remote monitoring server 4 has a function to analyze the operation information log acquired from the wireless communication device 3, a function to present to the user information regarding maintenance / replacement recommendations for the air conditioner 2 based on the analysis results, and the like, but a description of these functions will be omitted.

[0039] The driving information log acquisition unit 400 receives and acquires the driving information log sent from the wireless communication device 3 and stores the acquired driving information log in the auxiliary storage device 44. The communication line activation unit 401 is an example of a communication line activation means according to the present disclosure. The communication line activation unit 401 activates the cellular communication line of the wireless communication device 3. In detail, when a remote monitoring service for the air conditioner 2 is started (including when it is restarted), the communication line activation unit 401 communicates with a server of a telecommunications carrier (not shown) (hereinafter referred to as the "telecommunications carrier server") and instructs the telecommunications carrier server to activate the cellular communication line of the wireless communication device 3. This activates the cellular communication line of the wireless communication device 3. Furthermore, when the remote monitoring service for the air conditioner 2 is stopped, the communication line activation unit 401 periodically (e.g., every one to two weeks) instructs the telecommunications carrier server to activate the cellular communication line of the wireless communication device 3.

[0040] The communication line disabling unit 402 is an example of a communication line disabling means according to the present disclosure. The communication line disabling unit 402 disables the cellular communication line of the wireless communication device 3. In particular, when the remote monitoring service for the air conditioner 2 is stopped, the communication line disabling unit 402 communicates with the telecommunications carrier server and instructs the telecommunications carrier server to disable the cellular communication line of the wireless communication device 3 after the wireless communication device 3 is notified of the stop of the remote monitoring service and is instructed to disable transmission using the cellular communication line. This disables the cellular communication line of the wireless communication device 3. Furthermore, when the remote monitoring service for the air conditioner 2 is stopped, the communication line disabling unit 402 instructs the telecommunications carrier server to disable the cellular communication line of the wireless communication device 3 after the wireless communication device 3 receives a timestamp correction completion notification and the wireless communication device 3 is instructed to disable transmission using the cellular communication line.

[0041] The transmission enable / disable switching instruction unit 403 is an example of a transmission enable instruction means according to the present disclosure. The transmission enable / disable switching instruction unit 403 instructs the wireless communication device 3 to enable or disable transmission using the cellular communication line. In particular, when the cellular communication line of the wireless communication device 3 is enabled, the transmission enable / disable switching instruction unit 403 transmits a notification to the wireless communication device 3 instructing it to enable transmission using the cellular communication line.

[0042] Furthermore, when a notification indicating the stop of the remote monitoring service is transmitted to the wireless communication device 3 by the service stop notification unit 405 (described later), the transmission enable / disable switching instruction unit 403 transmits a notification instructing the wireless communication device 3 to disable transmission using the cellular communication line. Furthermore, when the remote monitoring service is stopped and a timestamp correction completion notification is received from the wireless communication device 3, the transmission enable / disable switching instruction unit 403 transmits a notification instructing the wireless communication device 3 to disable transmission using the cellular communication line.

[0043] The service start notification unit 404 is an example of a service start notification means according to the present disclosure. When a remote monitoring service for the air conditioner 2 is started, the service start notification unit 404, upon receiving a timestamp correction completion notification from the wireless communication device 3, transmits a service start notification indicating the start of the remote monitoring service to the wireless communication device 3. Upon receiving the service start notification, the wireless communication device 3 turns on a service enable flag.

[0044] The service stop notification unit 405 is an example of a service stop notification means according to the present disclosure. When the remote monitoring service for the air conditioner 2 is stopped, the service stop notification unit 405 transmits a service stop notification indicating the stop of the remote monitoring service to the wireless communication device 3. Upon receiving the service stop notification, the wireless communication device 3 turns off the service enable flag.

[0045] <Operation of Remote Monitoring Server 4> The operation of the remote monitoring server 4 while the remote monitoring service is stopped will be described below with reference to Fig. 6. While the remote monitoring service is stopped, the remote monitoring server 4 performs the following operations periodically (for example, every 1 to 2 weeks).

[0046] (Step S100) The remote monitoring server 4 activates the cellular communication line of the wireless communication device 3. Specifically, the remote monitoring server 4 communicates with a carrier server (not shown) and instructs the carrier server to activate the cellular communication line of the wireless communication device 3. This activates the cellular communication line of the wireless communication device 3. Thereafter, the process of the remote monitoring server 4 proceeds to step S101.

[0047] (Step S101) The remote monitoring server 4 transmits a notification instructing the wireless communication device 3 to enable transmission using a cellular communication line. After that, the process of the remote monitoring server 4 proceeds to step S102.

[0048] (Step S102) The remote monitoring server 4 determines whether or not the timestamp correction by the wireless communication device 3 has been completed. Specifically, the remote monitoring server 4 determines whether or not a timestamp correction completion notice indicating that the timestamp correction has been completed has been received from the wireless communication device 3. If the timestamp correction completion notice has been received from the wireless communication device 3 (step S102; YES), the processing of the remote monitoring server 4 proceeds to step S103. On the other hand, if the timestamp correction completion notice has not been received from the wireless communication device 3 (step S102; NO), the remote monitoring server 4 waits until the notice is received.

[0049] (Step S103) The remote monitoring server 4 transmits a notification instructing the wireless communication device 3 to disable transmission using the cellular communication line. After that, the process of the remote monitoring server 4 proceeds to step S104.

[0050] (Step S104) The remote monitoring server 4 disables the cellular communication line of the wireless communication device 3. In detail, the remote monitoring server 4 communicates with the telecommunications carrier server and instructs the telecommunications carrier server to disable the cellular communication line of the wireless communication device 3. As a result, the cellular communication line of the wireless communication device 3 is disabled.

[0051] <Operation of Wireless Communication Device 3> Hereinafter, with reference to FIG. 7, the operation of the wireless communication device 3 while the remote monitoring service is stopped will be described.

[0052] (Step S200) The wireless communication device 3 determines whether or not it has received a notification instructing it to enable transmission using a cellular communication line from the remote monitoring server 4. If it has received the notification from the remote monitoring server 4 (step S200; YES), the processing of the wireless communication device 3 proceeds to step S201. On the other hand, if it has not received the notification from the remote monitoring server 4 (step S200; NO), the processing of the wireless communication device 3 proceeds to step S205.

[0053] (Step S201) The wireless communication device 3 enables transmission using the cellular communication line. Specifically, the wireless communication device 3 turns on a transmission enable flag. Thereafter, the process of the wireless communication device 3 proceeds to step S202.

[0054] (Step S202) The wireless communication device 3 executes time synchronization. That is, the wireless communication device 3 accesses the time server 5 by communication using a cellular communication line and acquires time information indicating the current time. The wireless communication device 3 then updates the current time managed by itself based on the acquired time information and switches the time synchronization flag to ON. Thereafter, the processing of the wireless communication device 3 proceeds to step S203.

[0055] (Step S203) The wireless communication device 3 corrects, based on the current time, the timestamps of all driving information to which tentative time information has been assigned among the driving information stored in the auxiliary storage device 35. After that, the process of the wireless communication device 3 proceeds to step S204.

[0056] (Step S204) The wireless communication device 3 transmits a timestamp correction completion notification to the remote monitoring server 4 by communication using the cellular communication line. After that, the processing of the wireless communication device 3 returns to step S200.

[0057] (Step S205) The wireless communication device 3 determines whether or not it has received a notification instructing it to disable transmission using the cellular communication line from the remote monitoring server 4. If it has received the notification from the remote monitoring server 4 (step S205; YES), the processing of the wireless communication device 3 proceeds to step S206. On the other hand, if it has not received the notification from the remote monitoring server 4 (step S205; NO), the processing of the wireless communication device 3 proceeds to step S207.

[0058] (Step S206) The wireless communication device 3 disables transmission using the cellular communication line. Specifically, the wireless communication device 3 turns off the transmission enable flag. Thereafter, the processing of the wireless communication device 3 returns to step S200.

[0059] (Step S207) The wireless communication device 3 determines whether or not the timing has arrived to acquire operation information from the air conditioner 2. As described above, in this embodiment, the wireless communication device 3 periodically (e.g., every minute) acquires operation information from the air conditioner 2. If the timing has arrived (step S207; YES), the processing of the wireless communication device 3 proceeds to step S208. On the other hand, if the timing has not arrived (step S207; NO), the processing of the wireless communication device 3 returns to step S200.

[0060] (Step S208) The wireless communication device 3 acquires operating information from the air conditioner 2. Specifically, the wireless communication device 3 transmits a command via the communication line 6 to the air conditioner 2 requesting that it transmit operating information, and receives and acquires the operating information transmitted from the air conditioner 2 in response to the command. After that, the processing of the wireless communication device 3 proceeds to step S209.

[0061] (Step S209) The wireless communication device 3 assigns a timestamp to the acquired driving information. After that, the process of the wireless communication device 3 proceeds to step S210.

[0062] (Step S210) The wireless communication device 3 determines whether the time synchronization flag is OFF. If the time synchronization flag is OFF (step S210; YES), the process of the wireless communication device 3 proceeds to step S211. On the other hand, if the time synchronization flag is not OFF, i.e., is ON (step S210; NO), the process of the wireless communication device 3 returns to step S200.

[0063] (Step S211) The wireless communication device 3 further adds provisional time information to the time information to which the time stamp was added in step S209, indicating that the time stamp is an inaccurate provisional time. After that, the process of the wireless communication device 3 returns to step S200.

[0064] <Processing of the Remote Monitoring System 1 While the Remote Monitoring Service is Stopped> FIG. 8 is a communication sequence diagram showing the flow of processing of the remote monitoring system 1 while the remote monitoring service is stopped.

[0065] (Step S300) The remote monitor server 4 enables the cellular communication line of the wireless communication device 3.

[0066] (Step S301) The remote monitoring server 4 transmits to the wireless communication device 3 a notification instructing the wireless communication device 3 to enable transmission using a cellular communication line.

[0067] (Step S302) When receiving a notification from the remote monitor server 4 instructing to enable transmission using the cellular communication line, the wireless communication device 3 enables transmission using the cellular communication line.

[0068] (Step S303) The wireless communication device 3 executes time synchronization.

[0069] (Step S304) The wireless communication device 3 corrects the timestamps of all pieces of driving information to which tentative time information has been added.

[0070] (Step S305) The wireless communication device 3 transmits a timestamp correction completion notice indicating that the timestamp correction has been completed to the remote monitoring server 4 via communication using the cellular communication line.

[0071] (Step S306) When the remote monitor server 4 receives the timestamp correction completion notification from the wireless communication device 3, the remote monitor server 4 transmits a notification to the wireless communication device 3 instructing it to disable transmission using the cellular communication line.

[0072] (Step S307) When the wireless communication device 3 receives the notification from the remote monitor server 4 instructing to disable transmission using the cellular communication line, the wireless communication device 3 disables transmission using the cellular communication line.

[0073] (Step S308) The remote monitor server 4 disables the cellular communication line of the wireless communication device 3.

[0074] As described above, according to the remote monitoring system 1 of this embodiment, while the remote monitoring service is stopped, the remote monitoring server 4 periodically activates the cellular communication line of the wireless communication device 3, and the wireless communication device 3 performs time synchronization. After the time synchronization is completed, the timestamp of the driving information, which has been assigned a timestamp based on an inaccurate temporary time, is corrected based on the accurate current time. This makes it possible to effectively utilize the driving information log during the period when the remote monitoring service is stopped.

[0075] Furthermore, during the period when the remote monitoring service is stopped, the remote monitoring server 4 only needs to activate the cellular communication line of the wireless communication device 3 at regular intervals (for example, every 1 to 2 weeks), and since it does not take a long time to perform time synchronization and correct the timestamp, communication costs can be kept low.

[0076] Furthermore, there is no need to install a power source such as a large-capacity electrolytic capacitor or secondary battery to ensure power to the RTC, and the wireless communication device 3 can be manufactured and maintained at low cost.

[0077] (Variation 1) The remote monitoring server 4 may be an example of a time information providing means according to the present disclosure. That is, the remote monitoring server 4 may be configured to have a function for distributing time information indicating the accurate current time. In this case, when transmission using a cellular communication line is enabled, the wireless communication device 3 accesses the remote monitoring server 4 via communication using the cellular communication line to obtain the time information.

[0078] (Modification 2) The wireless communication device 3 may be configured to communicate with a plurality of air conditioners via wired communication and acquire operation information from each air conditioner. In this case, the operation information includes information for identifying the corresponding air conditioner.

[0079] (Modification 3) The wireless communication device 3 may be configured to include an RTC. In this case, the power source for the RTC is configured from a small-capacity capacitor that does not undergo chemical change.

[0080] (Variation 4) The wireless communication device 3 may receive a notification from the remote monitoring server 4 instructing to disable transmission using the cellular communication line, disable transmission using the cellular communication line, and then transmit a transmission disablement completion notification indicating that disabling of transmission using the cellular communication line has been completed to the remote monitoring server 4. In this case, upon receiving the transmission disablement completion notification, the remote monitoring server 4 disables the cellular communication line of the wireless communication device 3.

[0081] (Variation 5) While the remote monitoring service is stopped, the remote monitoring server 4 may transmit a notification to the wireless communication device 3 instructing it to enable transmission using a cellular communication line, and then periodically inquire about the progress of the operation from the wireless communication device 3. In this case, the wireless communication device 3 does not need to transmit a timestamp correction completion notification to the remote monitoring server 4, and does not need to transmit the transmission disable completion notification in Variation 4 to the remote monitoring server 4.

[0082] (Variation 6) When the remote monitoring service is stopped, once the timestamp correction is completed, the wireless communication device 3 may transmit the log of driving information with the corrected timestamp stored in the auxiliary storage device 35 to the remote monitoring server 4 via communication using a cellular communication line.

[0083] (Variation 7) While the remote monitoring service is stopped, the wireless communication device 3 may lengthen the interval at which it acquires operation information from the air conditioner 2 compared to when the remote monitoring service is running, or may reduce the size of the acquired operation information. For example, the size of the acquired operation information can be reduced by reducing the types of sensors that are the target of the operation information or by lowering the resolution of the measurement results of each sensor. Furthermore, the wireless communication device 3 may compress the log of operation information acquired while the remote monitoring service is stopped and save it in the auxiliary storage device 35.

[0084] (Variation 8) All or part of the functional units (see FIG. 4) of the wireless transmission device 3 may be implemented by dedicated hardware. Also, all or part of the functional units (see FIG. 5) of the remote monitoring server 4 may be implemented by dedicated hardware. The dedicated hardware may be, for example, a single circuit, a composite circuit, a programmed processor, an ASIC (Application-Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof.

[0085] The technical ideas according to the above-described modifications may be realized independently or in appropriate combination.

[0086] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope. Furthermore, the above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. In other words, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0087] 1 Remote monitoring system, 2 Air conditioner, 3 Wireless communication device, 4 Remote monitoring server, 5 Time server, 6 Communication line, 30 First communication interface, 31 Second communication interface, 32, 41 CPU, 33, 42 ROM, 34, 43 RAM, 35, 44 Auxiliary storage device, 36, 45 Bus, 40 Communication interface, 300 Operation information acquisition unit, 301 Timestamp assignment unit, 302 Time management unit, 303 Transmission enable / disable switching unit, 304 Operation information log transmission unit, 305 Time synchronization unit, 306 Timestamp correction unit, 307 Correction completion notification unit, 400 Operation information log acquisition unit, 401 Communication line activation unit, 402 Communication line disable unit, 403 Transmission enable / disable switching instruction unit, 404 Service start notification unit, 405 Service stop notification unit

Claims

1. A server and a wireless communication device, The server, a communication line enabling means for periodically enabling a cellular communication line of the wireless communication device while the remote monitoring service is stopped; a communication line invalidation means for invalidating the cellular communication line when a time stamp correction completion notice indicating that correction of the time stamp has been completed is received from the wireless communication device while the remote monitoring service is stopped, The wireless communication device includes: An operation information acquisition means for acquiring operation information from an air conditioner; a time stamp giving means for giving a time stamp to the acquired driving information; a time synchronization means for acquiring time information indicating a current time from a time information providing means by communication using the cellular communication line; a time stamp correction means for correcting time stamps of all operation information acquired from the air conditioner during the period from when the air conditioner is started until when the time information is acquired by the time synchronization means; and a correction completion notification means for transmitting a timestamp correction completion notification to the server via communication using the cellular communication line when the timestamp correction means completes correction of the timestamps of all of the driving information.

2. The communication line activation means instructs a communication carrier server to activate a cellular communication line of the wireless communication device; 2. The remote monitoring system according to claim 1, wherein the communication line invalidation means instructs the communication carrier server to invalidate the cellular communication line of the wireless communication device.

3. the server further comprises a transmission activation instruction means for instructing the wireless communication device to activate transmission using the cellular communication line after the cellular communication line of the wireless communication device is activated by the communication line activation means, The wireless communication device includes: a transmission validation means for validating the transmission when receiving an instruction to validate the transmission from the server; 3. The remote monitoring system according to claim 1, wherein the time synchronization means acquires the time information from the time information providing means when the transmission becomes effective.

4. The server, a service start notification means for transmitting a service start notification indicating the start of the remote monitoring service to the wireless communication device when the remote monitoring service is started; a service stop notification means for transmitting a service stop notification indicating the stop of the remote monitoring service to the wireless communication device when the remote monitoring service is stopped, The remote monitoring system of claim 1 or 2, wherein the wireless communication device determines that the remote monitoring service is enabled when it receives the service start notification from the server, and determines that the remote monitoring service is disabled when it receives the service stop notification from the server.

5. An operation information acquisition means for acquiring operation information from an air conditioner; a time stamp giving means for giving a time stamp to the acquired driving information; a time synchronization means for acquiring time information indicating a current time from a time information providing means by communication using a cellular communication line; a time stamp correction means for correcting time stamps of all operation information acquired from the air conditioner during the period from when the air conditioner is started until when the time information is acquired by the time synchronization means; and a correction completion notification means for transmitting a timestamp correction completion notification indicating that the timestamp correction has been completed to a server via communication using the cellular communication line when the timestamp correction means has completed the correction of the timestamps of all of the driving information.

6. a communication line enabling means for periodically enabling a cellular communication line of the wireless communication device while the remote monitoring service is stopped; a communication line disabling means for disabling the cellular communication line when a timestamp correction completion notification indicating that timestamp correction has been completed is received from the wireless communication device while the remote monitoring service is stopped.

7. The communication line activation means instructs a communication carrier server to activate a cellular communication line of the wireless communication device; The server according to claim 6 , wherein the communication line invalidation means instructs the communication carrier server to invalidate the cellular communication line of the wireless communication device.

8. The server While the remote monitoring service is stopped, periodically activate the cellular communication line of the wireless communication device, When a time stamp correction completion notification indicating that the time stamp correction has been completed is received from the wireless communication device while the remote monitoring service is stopped, the cellular communication line is disabled; The wireless communication device, Acquires operating information from air conditioners, A timestamp is added to the acquired driving information, acquiring time information indicating the current time from a time information providing means by communication using the cellular communication line; When the time information is acquired, the time stamps of all operation information acquired from the air conditioner from start-up to acquisition of the time information are corrected; When correction of the timestamps of all the driving information is completed, a notification of completion of the timestamp correction is transmitted to the server by communication using the cellular communication line.

9. The remote monitoring method according to claim 8 , wherein the server instructs a communication carrier server to enable or disable a cellular communication line of the wireless communication device.