JP5193143B2 - Fire alarm system - Google Patents

Description

  The present invention comprises a plurality of fire alarms that perform wireless communication using radio waves as a medium, and not only each fire alarm issues a warning itself, but also a fire alarm in which all the fire alarms issue a warning in conjunction with each other. It is about the system.

  Conventionally, when a fire is detected, an alarm is issued, and a message notifying other fire alarms of fire detection is notified by radio communication using radio waves as a medium, and other fire alarms that receive the message also issue an alarm. Thus, various fire alarm systems are provided in which all fire alarms issue an alarm in conjunction with each other (see, for example, Patent Documents 1 and 2).

  In the conventional example described in Patent Document 1, each fire alarm relays a message received by wireless communication from another fire alarm to another fire alarm, so-called multi-hop communication, Fire alarms that do not receive radio waves can be linked together. However, each fire alarm needs to be in a state in which wireless communication with at least one of the other fire alarms is possible.

JP 2008-9480 A JP 2008-271374 A

  By the way, in recent years, with the spread of the Internet, the number of homes where wireless LAN is introduced is increasing, and radio waves in the frequency band used in the wireless LAN interfere with radio waves in the frequency band used in the fire alarm system. There is a possibility that wireless communication is hindered. In addition to the wireless LAN, there are many electrical devices that emit electromagnetic noise, such as household electrical devices that use radio waves (such as radio remote controls) and microwave ovens. Furthermore, radio wave propagation characteristics may change and communication may be hindered by the installation of metallic fixtures or the installation of new walls in a house. Therefore, even if wireless communication is possible at the time of installation of the fire alarm, if a new wireless LAN or electrical equipment is introduced after installation or there is an environmental change that affects radio wave propagation, In some cases, the usage status of fire alarms changed, making it difficult to communicate wirelessly between fire alarms. When a fire occurs with such a situation left unattended, there is a possibility that message transmission by wireless communication becomes impossible and alarms cannot be linked with all fire alarms.

  Therefore, in order to prevent the emergence of fire alarms that do not emit alarms in conjunction with the occurrence of a fire, periodically make sure that all fire alarms can communicate wirelessly with at least one other fire alarm. If there is a fire alarm device that cannot be wirelessly communicated, it is necessary to take measures to enable wireless communication immediately, for example, removal of obstruction factors for wireless communication or change of the location of the fire alarm device.

  However, when periodically checking whether wireless communication is possible as described above, which fire alarm each other fire alarm checks whether wireless communication is possible, and the mutual wireless communication There is also a problem that radio signals collide between fire alarms that do not overlap areas, and the algorithm for checking the availability of wireless communication becomes very complicated. In addition, wireless communication may be possible only in one direction depending on the position of the noise source, and wireless communication may not be possible in the opposite direction. Therefore, it is desirable to check the availability of wireless communication in both directions for each fire alarm, but doing so further complicates the algorithm for checking the availability of wireless communication.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fire alarm system capable of relatively easily checking whether wireless communication is possible in all fire alarm devices.

In order to achieve the above object, the invention of claim 1 includes a plurality of fire alarms for transmitting and receiving radio signals using radio waves as media, and each fire alarm includes a fire detection means for detecting a fire, and a fire alarm. Alarm means, a transmitting means for transmitting a radio signal, a receiving means for receiving a radio signal, and when a fire is detected by the fire detecting means, the alarm means is notified of a fire alarm and other fire alarms A radio signal including a fire alarm message for informing a fire alarm is transmitted from a transmission means, and a radio signal transmitted from another fire alarm device is received by a reception means to receive an alarm when the fire alarm message is received. Control means for notifying a fire alarm to the means, and the control means receives a radio signal including a fire alarm message transmitted from any of the fire alarms by the receiving means. The fire alarm system relays the fire alarm message by transmitting a wireless signal including the fire alarm message from the transmission means, and the control means of any one of the fire alarms is for checking whether wireless communication is possible or not. A wireless signal including a check message is transmitted from a transmission unit at a constant cycle, and all the fire alarm control units other than the one fire alarm device receive a wireless signal including the check message by a reception unit. When receiving, when the wireless signal including the check message is transmitted from the transmission means to relay the check message, and the period in which the wireless signal including the check message is not received exceeds a predetermined period that is not shorter than the period determines that the wireless communication is impossible, the one fire alarm is being determined by the initial setting To.

  According to the invention of claim 1, it can be determined that wireless communication is possible with all fire alarms if wireless signals including a check message can be received within a predetermined period in all fire alarms. If a period during which an alarm device cannot receive a wireless signal including a check message exceeds a predetermined period, it can be determined that wireless communication is not possible with any fire alarm device. As a result, the availability of wireless communication can be checked relatively easily in all fire alarms.

The invention of claim 2 is characterized in that, in the invention of claim 1 , the one fire alarm is periodically replaced from among a plurality of fire alarms.

According to the invention of claim 2 , since the transmission path of the check message changes, it is possible to determine whether or not wireless communication is possible in both directions.

The invention according to claim 3 is the invention according to claim 2 , wherein the one fire alarm is periodically changed in an order determined based on a serial number unique to each fire alarm. .

According to a fourth aspect of the present invention, in the second aspect of the present invention, the one fire alarm is periodically changed in an order determined by an initial setting.

  According to the present invention, it is possible to relatively easily check whether wireless communication is possible in all fire alarms.

1 shows an embodiment of the present invention, where (a) is a block diagram of a fire alarm device, and (b) is a system configuration diagram of a fire alarm system. It is a frame format of the radio signal in the same as above. (A), (b) is explanatory drawing of the multihop communication in the same as the above. It is a flowchart for demonstrating the periodic confirmation process in the same as the above.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1B, the fire alarm system of the present embodiment includes a plurality (9 in the illustrated example) of fire alarms TR. In the following description, when the fire alarm devices TR are individually shown, they are expressed as fire alarm devices TR1, TR2,..., TR9, and when collectively shown, they are expressed as fire alarm devices TR.

  As shown in FIG. 1A, the fire alarm device TR transmits a radio signal using radio waves as a medium from the antenna 3 and receives a radio signal transmitted from another fire alarm device TR by the antenna 3. And an alarm unit 5 for reporting a fire alarm (hereinafter referred to as “alarm sound”) by sound (buzzer sound, voice message, etc.), a microcomputer, a rewritable nonvolatile semiconductor memory, etc. A fire alarm message for causing the alarm unit 5 to sound an alarm sound and to notify the other fire alarm device TR when a fire is detected by the fire detection unit 4 with the memory unit 1a as a main component. A control unit 1 that transmits a wireless signal including the wireless signal from the wireless transmission / reception unit 2 and a battery power supply unit 6 that supplies a battery such as a dry battery as a power source and supplies operating power to each unit are provided. Each of the fire alarm devices TR1, TR2,..., TR9 is assigned a unique identification code and stored in the memory unit 1a, and a radio signal destination (transmission destination) and a source fire alarm are identified by the identification code. The devices TR1, TR2,..., TR9 can be specified.

  The radio transmission / reception unit 2 transmits / receives a radio signal using radio waves as a medium in accordance with “radio station of low power security system” defined in Article 6, Paragraph 4, Item 3 of the Radio Law Enforcement Regulations. In addition, the fire detection unit 4 detects fire by detecting smoke, heat, flames, and the like generated with the fire, for example. However, detailed configurations of the wireless transmission / reception unit 2 and the fire detection unit 4 are well known in the art and will not be described in detail.

  The control unit 1 realizes various functions to be described later by executing a program stored in a memory (ROM or EEPROM) (not shown) by a microcomputer. When the fire detection unit 4 detects the occurrence of a fire, the control unit 1 drives a buzzer included in the alarm unit 5 to sound an alarm sound, or an alarm stored in the memory (or the memory unit 1a) in advance. In order to notify a fire alarm by sounding a voice message (for example, “This is a fire”) on the speaker, and to notify the fire alarm also in other fire alarm devices TR, a radio signal including a fire alarm message is transmitted. The wireless transmission / reception unit 2 transmits the data. Also, when the wireless transmission / reception unit 2 receives a wireless signal transmitted from another fire alarm device TR, the control unit 1 controls the alarm unit 5 to sound an alarm sound. That is, in the control unit 1, when the fire detection unit 4 detects a fire, the alarm unit 5 sounds an alarm sound to notify the fire alarm, and the wireless transmission / reception unit 2 transmits a radio signal including the fire alarm message. Have.

  Here, in the radio equipment regulation Article 49-17 “Radio equipment of radio stations of the low power security system” of the Radio Law Enforcement Regulation, the period during which radio signals may be continuously transmitted (transmission period) is 3 seconds or less. It is stipulated that the period (pause period) provided between the transmission period and the transmission period in which the radio signal should not be transmitted is 2 seconds or more (see No. 5 of the same article). For this reason, in the control unit 1 in the present embodiment, the wireless signal is transmitted during the transmission period that complies with the wireless facility rules, and the transmission is stopped and received during the suspension period.

  In order to extend the battery life of the battery power supply unit 6 as much as possible, the control unit 1 repeatedly counts a predetermined intermittent reception interval (however, the intermittent reception interval is longer than the transmission period) by a timer built in the microcomputer. In addition, every time the intermittent reception interval is counted, the wireless transmission / reception unit 2 is activated to check whether a desired radio wave (radio signal transmitted by another fire alarm device TR) can be received, and the radio wave is captured. If not, the average power consumption is greatly reduced by immediately stopping the wireless transmission / reception unit 2 and shifting to the standby state. The radio wave reception check is performed based on the received signal strength indication signal (Receiving Signal Strength Indication: RSSI signal) output from the wireless transmission / reception unit 2 and is a DC voltage signal proportional to the magnitude of the received signal strength. The details are well known in the art and will be omitted.

  FIG. 2 shows a frame format of a radio signal transmitted and received by the fire alarm device TR. A synchronization bit (preamble: PA), a frame synchronization pattern (unique word: UW), a destination address DA, a source address SA, a message M, One frame is composed of a CRC code. Here, if the identification code of each fire alarm device TR is set as the destination address DA, only the fire alarm device TR of the identification code receives a radio signal and acquires a message. By setting a special bit string that is not assigned to the fire alarm TR (for example, a bit string with all bits set to 1), a wireless signal is broadcast (multicast) to obtain a message for all the fire alarm TRs. Can be made. For example, a radio signal including a fire warning message is broadcast from the fire alarm device TR of the fire source.

  Here, in the fire alarm system of the present embodiment, similarly to the conventional example of Patent Document 1, multi-hop communication is performed by relaying a radio signal transmitted from one fire alarm TR to another fire alarm TR. ing. For example, in FIG. 1B, an arrow is written between two fire alarms TR that can wirelessly communicate with each other, and wireless communication is not performed between fire alarms TR that are not filled with arrows. Indicates that it is not possible. That is, only four fire alarm devices TR1, TR3, TR4, and TR5 can directly communicate with the fire alarm device TR2, and only the fire alarm devices TR6, TR8, and TR9 can communicate with the fire alarm device TR5 directly. There are only three units, and only one unit of the fire alarm device TR3 can directly communicate with the fire alarm device TR7.

  For example, as shown in FIG. 3A, when the fire alarm device TR1 first detects a fire, a radio signal including a fire alarm message is transmitted from the fire source fire alarm device TR1 (multicast), and the fire alarm device is transmitted. Only the fire alarm device TR2 capable of wireless communication with the device TR1 can receive the wireless signal. Then, the fire alarm device TR2 broadcasts (relays) a radio signal including the fire alarm message, so that the three fire alarm devices TR3 to TR5 can receive the radio signal. Further, the fire alarm devices TR3 and TR5 respectively transmit (relay) radio signals including a fire alarm message, so that the remaining four fire alarm devices TR6 to TR9 can receive the radio signals. And if a fire alarm message is delivered to all the fire alarm devices TR1 to TR9, not only the fire alarm device TR1 that detected the fire but also all the fire alarms including the fire alarm devices TR2 to TR9 other than the fire source device The devices TR1 to TR9 can notify the fire alarm in conjunction with each other.

  Similarly, as shown in FIG. 3B, when the fire alarm device TR2 first detects a fire, a radio signal including a fire alarm message is broadcast from the fire source fire alarm device TR2, and the fire alarm device TR2 The four fire alarm devices TR1, TR3 to TR5 that can wirelessly communicate with each other can receive the wireless signal. The fire alarm devices TR3 and TR5 respectively transmit (relay) radio signals including a fire alarm message, so that the remaining four fire alarm devices TR6 to TR9 can receive the radio signals. And if a fire alarm message is delivered to all the fire alarm devices TR1 to TR9, not only the fire alarm device TR2 that detects the fire but also all the fire alarm devices TR1, TR3 to TR9 other than the fire source device The fire alarm devices TR1 to TR9 can notify the fire alarm in conjunction with each other.

  By the way, the communication path described above (the arrow in FIG. 1B) is not permanent, and may disappear due to a change in the use state of radio waves as described in the related art. Therefore, in the fire alarm system of the present embodiment, a process (periodic confirmation process) for periodically confirming (checking) the normality of the communication path is executed by each fire alarm device TR. Hereinafter, the periodic confirmation process which is the gist of the present invention will be described in detail with reference to the flowchart shown in FIG.

  First, when all the fire alarm devices TR1 to TR9 are turned on at approximately the same time and the power supply from the battery power supply unit 6 to the control unit 1 is started, the control unit 1 activates the wireless transmission / reception 2 to each other. A wireless signal is transmitted and received, and the self-identification code stored in the memory unit 1a is notified to the other fire alarm device TR (step S1). Moreover, the control part 1 memorize | stores the identification code notified from other fire alarm devices TR in the memory part 1a, and determines own terminal number N based on these identification codes (step S2). Specifically, all the identification codes including the self identification code are arranged in ascending order, and the rank (integer of 1 to 9) of the self identification code at that time is the terminal number N (= 1, 2,..., 9). And Therefore, any terminal number N of 1 to 9 is assigned to all the fire alarm devices TR1 to TR9 without duplication. When the terminal number N is determined, the control unit 1 starts a timer and starts counting a confirmation cycle T (for example, 24 hours).

  The control unit 1 assigns 1 to the variable K and initializes it (step S3), and determines whether or not the variable K matches its own terminal number N (step S4). For example, when the terminal number N of the fire alarm device TR1 is 1 and matches the initial value (= 1) of the variable K, the control unit 1 of the fire alarm device TR1 until the timer completes the counting of the confirmation cycle T It waits (step S5), and when the confirmation cycle T elapses, a wireless signal including a periodic confirmation (for check) message is broadcast (multicast) from the wireless transmission / reception unit 2 (step S6). Thereafter, the control unit 1 of the fire alarm device TR1 substitutes K + 1 for the variable K (step S7) and returns to step S4.

  On the other hand, if the terminal number N does not match the variable K, the control unit 1 of the fire alarm device TR (in this case, TR2 to TR9) has a predetermined period with a check period T + α (for example, α = 10 minutes). (Step S8), it is determined whether or not a radio signal including a periodic confirmation message has been received in the intermittent reception until the predetermined period (= T + α) elapses (step S9). . Here, in the control unit 1 of each of the fire alarm devices TR2 to TR9, when a periodic confirmation message is received, it is relayed by multi-hop communication in the same manner as when the fire alarm message is received. Therefore, as long as all communication paths are normal, the wireless signal including the periodic confirmation message transmitted from the fire alarm device TR1 is transmitted to all other fires by the same multi-hop communication as the wireless signal including the fire notification message described above. It should be received by the alarm devices TR2 to TR9. Therefore, when the control unit 1 does not receive the periodic confirmation message within the predetermined period, in other words, when the period during which the wireless signal including the periodic confirmation message is not received by the wireless transmission / reception unit 2 exceeds the predetermined period, another fire alarm is issued. It is determined that a communication path abnormality (inability to wireless communication) has occurred with the device TR, and the alarm unit 5 is controlled to notify a periodic confirmation error (step S11).

  If the periodic confirmation message is received within the predetermined period, the control unit 1 determines that there is no abnormality in the communication path by the periodic confirmation, and adds 1 to the terminal number N of the fire alarm device TR1 that is the current periodic confirmation source. The obtained value is substituted for the variable K (step S10), and then the process returns to step S4. At this time, since the variable K is 2, the control unit 1 of the fire alarm device TR (for example, TR2) to which “2” is assigned to the terminal number N next time performs the processing of steps S4 to S7 described above. , And the control unit 1 of the other fire alarm devices TR1, TR3 to TR9 executes the processes of steps S8 to S11.

  As described above, in the fire alarm system of the present embodiment, if the periodic confirmation message transmitted from one of the fire alarm devices TR cannot be received by another fire alarm device TR, there is an abnormality in the communication path (wireless communication is not possible). Therefore, the control unit 1 of each fire alarm device TR only needs to determine whether or not a periodic confirmation message is received every predetermined period counted by the timer, and whether or not wireless communication is possible in all the fire alarm devices TR. It can be checked (checked) relatively easily. Here, it is possible to fix the fire alarm device TR that periodically transmits the periodic confirmation message to any of the fire alarm devices TR (for example, TR1), but the transmission of the periodic confirmation message as in the present embodiment. If the original fire alarm TR is changed in turn, the transmission path of the periodic confirmation message will change, so if any fire alarm TR fires, all fire alarms TR will be informed of the fire. It is possible to determine bidirectionally whether communication is possible in all the wireless communication paths required for the communication. In addition, when fixing the transmission source of the periodic confirmation message to any of the fire alarm devices TR, or when changing in turn, it may be determined based on the manufacturing number unique to each fire alarm device TR. However, it may be determined by the initial setting as in the present embodiment.

  In this embodiment, if the periodic confirmation message cannot be received even once in the confirmation (check) every confirmation cycle T, the control unit 1 notifies the regular confirmation error, but in the confirmation every confirmation cycle T, If the periodic confirmation message cannot be received continuously for a predetermined number of times of two or more, a periodic confirmation error may be notified.

TR Fire alarm 1 Control unit (control means)
2 Wireless transceiver (transmitting means, receiving means)
3 Antenna (transmitting means, receiving means)
4 Fire detection part (fire detection means)
5 Alarm section (alarm means)

Claims (4)

A plurality of fire alarms that transmit and receive radio signals using radio waves as a medium are provided, each fire alarm is a fire detection means that detects a fire, an alarm means that notifies a fire alarm, and a transmission means that transmits a radio signal A radio signal including a fire alarm message for notifying a fire alarm to the alarm means and receiving a fire alarm when the fire detecting means detects a fire with a receiving means for receiving a radio signal; A control unit that transmits from the transmission unit and receives a wireless signal transmitted from another fire alarm device by the reception unit and receives the fire alarm message, and causes the alarm unit to notify the fire alarm, and When the receiving means receives a radio signal including a fire alarm message transmitted from any of the fire alarm devices, the control means transmits a radio signal including the fire alarm message. By transmitting from the means A fire alarm system for relaying fire alarm messages,
The control means of any one of the fire alarm devices transmits a wireless signal including a check message for checking whether wireless communication is possible or not from the transmission means at a constant cycle,
The control means of all the other fire alarms except the one fire alarm, when the radio signal including the check message is received by the reception means, the radio signal including the check message is transmitted from the transmission means and checked. Determining that wireless communication is impossible when a period of not receiving a wireless signal including a check message exceeds a predetermined period not shorter than the period ,
The fire alarm system is characterized in that the one fire alarm is determined by an initial setting . The fire alarm system according to claim 1, wherein the one fire alarm is periodically replaced from among a plurality of fire alarms . The fire alarm system according to claim 2, wherein the one fire alarm device is periodically replaced in an order determined based on a serial number unique to each fire alarm device . The fire alarm system according to claim 2, wherein the one fire alarm is periodically changed in an order determined by initial setting .

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