JP6278439B2 - Wireless disaster prevention system - Google Patents

Description

The present invention relates to a wireless disaster prevention system that transmits a telegram wirelessly transmitted from a node such as a wireless sensor to another node.

  Conventionally, in a wireless disaster prevention monitoring system that monitors abnormalities such as fires in a warning area, a plurality of wireless sensors as sensor nodes are installed in the warning area such as each floor of a building. When a fire is detected, a telegram signal indicating the fire (hereinafter simply referred to as “telegram”) is wirelessly transmitted to a radio reception repeater as a radio disaster prevention node installed on a floor basis. In addition, a radio wave repeater that is a wireless relay node is installed on the way to relay messages from the wireless sensor.

  The radio reception repeater is connected to the sensor line from the receiver. When a message indicating a fire is received, an alarm current is sent to the sensor line when a relay contact or switching element is turned on to generate a fire alarm signal. Send to receiver. Upon receiving this fire alarm signal, the receiver issues a fire alarm by means such as sound.

  According to such a wireless disaster prevention system, a part of a sensor line generally laid on the ceiling or the like can be eliminated, wiring work is simplified, and the installation location of the sensor is also restricted by wiring. You can decide without. In addition, it can easily cope with system changes such as the addition of sensors.

  The wireless detector, radio wave repeater and wireless reception repeater constituting the wireless disaster prevention system are STD-30 (wireless equipment of a low power security system wireless station known as a standard of a specific low power wireless station in the 426 MHz band) Radio signals are transmitted and received based on (standard).

  STD-30 has an antenna power of 10 mW or less, and when using a radio wave with a frequency of 426.250 MHz or higher and 426.8375 MHz or lower, carrier sense is not obligatory, so by using a radio wave of this frequency, Wireless transmission is performed without performing carrier sense. In addition, carrier sense detects the reception level of radio waves of the same carrier frequency transmitted by other stations when performing wireless transmission, and when this reception level is equal to or higher than a predetermined threshold, wireless transmission is not performed. When the reception level is less than a predetermined threshold, wireless transmission is performed to avoid collision of radio waves having the same carrier frequency.

  In STD-30, since carrier sense is not obligated, the emission of the radio wave is stopped within 3 seconds after the radio wave is emitted, and the subsequent emission is not made after 2 seconds have elapsed. Is not required. Hereinafter, a time within 3 seconds during which radio waves can be emitted is referred to as a transmission allocation time, and a time of 2 seconds during which radio waves are stopped is referred to as a transmission suspension time. For this reason, STD-30 can be said to be a communication method that requires a predetermined transmission suspension time following a predetermined transmission allocation time.

In addition, the wireless sensor used as a sensor node in the wireless disaster prevention system uses a battery power source in order to increase the degree of freedom of installation without the need to secure a power source. Guaranteed battery life is exceeded. In addition, the transmission power of the wireless sensor is fixed to 10 mW, which is the maximum power that can be used in the current STD-30, in order to secure a sufficient communication distance, and the communication distance to the wireless reception repeater Is long, the radio wave repeater is installed in between to perform relay transmission.

JP-A-5-274580 JP 2001-290209 A JP 2011-071598 A

  By the way, in such a wireless disaster prevention monitoring system, when a fire is detected by a wireless sensor, a message indicating a fire is generated, and this message is transmitted with a transmission power of 10 mW within a transmission allocation time and received. When an ACK signal known as an acknowledgment signal (hereinafter referred to as “ACK”) is received from the wireless reception repeater or radio wave repeater on the side, it is determined that the transmission was successful and the transmission operation is terminated. .

  On the other hand, if an ACK from a wireless reception repeater or radio wave repeater on the receiving side is not received even if a message indicating a fire is transmitted from the wireless sensor, a transmission suspension time of 2 seconds is set. After the elapse of time, a retry operation for continuously transmitting a plurality of messages indicating a fire is performed again. If ACK cannot be received, the same transmission operation is repeated with a transmission pause time until the predetermined number of retries is reached.

  For this reason, it takes time for the recovery by the retry operation when the message transmission fails, and there is a case where the time delay from the detection of the fire by the wireless sensor to the output of the fire alarm by the receiver may become large.

  In addition, communication failure that causes failure in sending messages in the wireless disaster prevention system may be due to temporary noise from equipment installed in the surveillance area, or due to temporary causes such as changes in the radio wave environment due to movement of people or objects. However, it is assumed that the communication failure has been recovered at the timing of the transmission suspension time when ACK cannot be received during message transmission. However, it takes time to communicate normally because the transmission suspension time is required. There is a problem that takes.

It is an object of the present invention to provide a wireless disaster prevention system that can improve the reliability of communication against a communication failure for a communication method that requires a predetermined transmission suspension time following a predetermined transmission allocation time. .

The present invention transmits and receives a radio signal between a child node and a parent node based on a communication scheme that requires a predetermined transmission suspension time following a predetermined transmission allocation time, and wirelessly transmits between the child node and the transmission allocation time. In a disaster prevention radio system that can transmit signals intermittently,
Child nodes within transmission allocation time, the predetermined transmission power after transmitting the radio signal including the transmission power information of the predetermined transmission power, if the radio signal acknowledgment from the parent node is not received, transmission allocation during the remaining time of the time until the radio signal acknowledgment is received, repeating the retransmission of radio signals by gradually increasing the predetermined transmission power, including transmission power information of the transmission power the increased It is characterized by.

The present invention transmits and receives a radio signal between a child node and a parent node based on a communication scheme that requires a predetermined transmission suspension time following a predetermined transmission allocation time, and wirelessly transmits between the child node and the transmission allocation time. In a disaster prevention radio system that can transmit signals intermittently,
When the child node does not receive a confirmation response radio signal from the parent node after transmitting a radio signal including transmission power information of the predetermined transmission power with a predetermined transmission power within the transmission allocation time, Until the acknowledgment radio signal is received during the remaining time, the predetermined transmission power is increased stepwise and the retransmission of the radio signal including the transmission power information of the increased transmission power is repeated. And
The parent node transmits an acknowledgment radio signal by changing transmission power according to transmission power information included in the received radio signal .

  According to the wireless disaster prevention system of the present invention, for example, when a child node is a sensor node and a parent node is a wireless disaster prevention node, a sensor node that functions as a child node transmits a wireless signal to the wireless disaster prevention node that functions as a parent node. In the case of transmitting a radio signal with a predetermined transmission power within the transmission allocation time, and after transmission, if an acknowledgment radio signal (ACK) is not received from the radio disaster prevention node, until an acknowledgment radio signal is received Since the initial transmission power is increased and wireless signal transmission is repeated, even if transmission of a wireless signal indicating a fire fails due to a change in radio wave environment or communication failure, the transmission power is increased while the transmission power is increased. By transmitting, even in the same radio wave environment that failed to transmit first, the S / N ratio at the wireless disaster prevention node on the receiving side is improved, and a wireless signal indicating a fire By reducing the number of retransmissions of wireless signals due to transmission failure, it is possible to suppress the time delay from the detection of a fire at the sensor node to the output of a fire alarm at the wireless transmission destination To do.

  These effects are the same when the child node is a sensor node and the parent node is a radio relay node, or when the child node is a radio relay node and the parent node is a radio disaster prevention node.

In addition, in order to manufacture and sell sensor node and radio relay node equipment whose transmission power can be changed, it is obliged to obtain technical standard conformity certification (technical standard conformity certification). If the transmission power can be changed to multi-stage transmission power within the range of the maximum transmission power, it is possible to apply for each node device as a specified low-power radio station that uses multi-stage transmission power, and the transmission power is set to a predetermined value. It can be put to practical use as it can be certified by the same treatment as when fixed to electric power.

Explanatory drawing which showed embodiment of the wireless disaster prevention system by this invention Block diagram showing an outline of the functional configuration of the wireless sensor Block diagram showing outline of functional configuration of radio repeater The block diagram which showed the outline of the functional structure of the repeater for radio | wireless reception, and a P-type receiver Explanatory drawing showing the message format used in the wireless disaster prevention system Time chart showing fire telegram transmission

[Wireless disaster prevention system]
(Overview of wireless disaster prevention system)
FIG. 1 is an explanatory view showing an embodiment of a wireless disaster prevention system according to the present invention. As shown in FIG. 1, wireless reception repeaters 12-1 to 12-3 functioning as wireless disaster prevention nodes are installed on each floor of a building 11 to be monitored, from a P-type receiver 10 that is a fire receiver. It is connected to sensor lines 18-1 to 18-3 drawn out by floor. In addition, radio reception repeaters 12-1 to 12-3 are connected to the power supply line 15 drawn out from the P-type receiver 10.

  Wireless sensors 16-11 to 16-14, 16-21 to 16-24, and 16-31 to 16-34 functioning as sensor nodes are installed on the floors 1F to 3F. In the present embodiment, the radio reception repeaters 12-1 to 12-3 function as radio wave relay nodes in order to prevent signal loss due to radio wave attenuation from radio sensors that are far away from each other. Radio wave repeaters 14-1 to 14-3 are installed.

  In the case where the wireless sensors 16-11 to 16-34, the radio wave repeaters 14-1 to 14-3, and the radio reception repeaters 12-1 to 12-3 are not distinguished, the wireless sensor 16 and the radio wave These are called the repeater 14 and the radio reception repeater 12.

  Here, regarding the parent-child relationship, the wireless sensor 16 and the wireless reception repeater 12 are in a parent-child relationship, the wireless sensor 16 is a child node, and the wireless reception relay 12 is a parent node. Further, the wireless sensor 16 and the radio relay 14 are also in a parent-child relationship, the wireless sensor 16 is a child node, and the radio relay 14 is a parent node. Furthermore, the radio wave repeater 14 and the radio reception repeater 12 are also in a parent-child relationship, the radio wave repeater 14 is a child node, and the radio reception repeater 12 is a parent node.

  The wireless sensor 16, the radio wave repeater 14, and the radio reception repeater 12 are radio waves having a frequency of 426.250 MHz or more and 426.8375 MHz or less in accordance with STD-30 which is a standard for a specific low power radio station for security. By using, wireless transmission is performed without performing carrier sense.

  In STD-30, since carrier sense is not obligated, the emission of the radio wave is stopped within 3 seconds after the radio wave is emitted, and the subsequent emission is not made after 2 seconds have elapsed. This is a communication system that requires a predetermined transmission allocation time, for example, T2 = 2 seconds, followed by a predetermined transmission suspension time T2 = 2 seconds.

  Furthermore, in STD-30, it is considered that re-transmission can be performed without providing a transmission suspension time of 2 seconds or more after stopping the emission only within 3 seconds after the radio wave is emitted. ing. Therefore, if the transmission allocation time T1 is within 3 seconds, retransmission can be repeated as necessary.

  In each of the wireless sensor 16 and the radio wave repeater 14, a unique node ID using a device ID is registered in advance.

  Since the wireless reception repeater 12, the radio wave repeater 14, and the wireless sensor 16 are constructed with a wireless network by floor, different network addresses (hereinafter simply referred to as “addresses”) are set for each floor. doing.

  In each of the radio wave repeater 14-1 and the radio reception repeater 12-1, a node ID for specifying a transmission source as a child node that receives a message based on the parent-child relationship is registered in advance. That is, node IDs of the wireless sensors 16-13 and 16-14 and the radio relay 14-1 that are child nodes are registered in advance in the wireless reception repeater 12-1. Also, node IDs of the wireless sensors 16-11 and 16-12 that are child nodes are registered in advance in the radio wave repeater 14-1.

  In the radio reception repeater 12-1, in the situation where various radio signals from the radio sensors 16-11 and 16-12 are normally received via the radio repeater 14-1, the radio repeater 14 is provided. Even when a message transmitted from the wireless sensors 16-11 and 16-12 is directly received without passing through -1, the wireless reception repeater 12- The node IDs of the wireless sensors 16-11 and 16-12 installed on the same floor (group) are also registered in one storage unit. The registration of the node ID of each device in the storage unit of the wireless reception repeater 12 may register the ID of each child node by communicating the wireless reception repeater 12 and other child nodes with each other. The node ID of the wireless sensor 16 previously registered in the radio repeater 14 is additionally registered in the storage unit of the radio reception repeater 12 by wireless transfer from the radio repeater 14 to the radio reception repeater 12. It may be configured.

  The 2F and 3F wireless reception repeaters 12-2 and 12-3 and the radio wave repeaters 14-2 and 14-3 have the same configuration.

  The wireless sensor 16 transmits, as wireless signals, a fire message indicating a fire, a fire recovery message indicating a fire recovery, a message used for system management such as a failure, a test, and a start-up.

  Further, the wireless sensor 16 can be changed to different transmission powers in multiple stages within a range where the maximum transmission power is 1 W (= 1000 mW) or less and a predetermined minimum transmission power, for example, 10 mW or more.

  The transmission power that can be changed by the wireless sensor 16 is set, for example, in the following three stages so that the transmission power can be changed.

Here, the transmission powers P1 to P3 are shown in units of [mW] and [dBm], and [dBm] is a unit of logarithmic expression based on 1 [mW].
dBm = 10 × log (reception strength [mW])
Can be calculated as

  In this case, for example, the wireless sensor 16 initially sets transmission power P1 = 10 mW, and when a transmission request is generated, transmits a message with the initially set transmission power P1 = 10 mW.

  In addition, the wireless sensor 16 normally terminates transmission when an ACK is received from the radio relay device 14 or the wireless reception relay device 12 as a parent node after transmitting a message with the initially set transmission power P1 = 10 mW. To do.

  If the wireless sensor 16 does not receive an ACK from the radio wave repeater 14 or the wireless reception repeater 12 after transmitting the message, the wireless sensor 16 receives the ACK during the remaining time of the transmission allocation time T1. Until the transmission power P1 = 10 mW, which is initially set, is increased step by step to transmission power P2 = 100 mW and P3 = 1000 mW, the retransmission of the message is repeated.

  When the wireless sensor 16 capable of changing the transmission power in multiple stages as described above is acquired as technical standard conformity certification (technical standard conformity certification) as a wireless device according to STD-30, it is 10 mW, 100 mW, and 1000 mW. By applying for a specific power-saving wireless device that uses this transmission power, it is possible to obtain the certification and put it to practical use in the same way as when the transmission power is fixed.

  The number of transmission power levels that can be changed by the wireless sensor 16 is arbitrary. For example, the number of stages may be further increased and set to the following five levels.

  Also in this case, for example, the wireless sensor 16 initially sets transmission power P1 = 10 mW, and if an ACK is not received after transmitting a message with the initially set transmission power P1 = 10 mW, the transmission allocation time Until the ACK is received during the remaining time of T1, the initial transmission power P1 = 10 mW is retransmitted while increasing the transmission power P2 (= 50 mW) to P5 (= 1000 mW) step by step. repeat.

  When the ACK cannot be received in this way, the radio repeater 14 performs the same transmission for repeating retransmission while increasing the transmission power stepwise.

  Here, the outline of the transmission operation will be described by taking the wireless sensor 16-11 as an example. When the wireless sensor 16-11 detects a fire, the wireless sensor 16-11 generates a predetermined-format message including fire data “hereinafter referred to as“ fire message ””, and the transmission power P1 = 10 mW, which initially sets the fire message. Transmission is performed to the radio wave repeater 14-1 as indicated by the communication path 15a, and when the transmission is completed, the operation is switched to the reception operation.

  When the radio repeater 14-1 receives a continuously transmitted fire message, it compares the transmission source ID included in this fire message with a pre-registered node ID, and treats it as a valid fire message when both match. An ACK is transmitted to the wireless sensor 16-11 with the initially set transmission power P1 = 10 mW.

  When the wireless sensor 16-11 stops the transmission operation and switches to the reception operation and receives the ACK transmitted by the radio wave repeater 14-1, it determines that the fire telegram has been transmitted normally and performs the transmission operation. Is terminated normally.

  On the other hand, when the wireless sensor 16-11 fails to receive the ACK, the initial setting transmission power P1 = 10 mW is changed to, for example, the next largest transmission power P2 = 100 mW in Table 1 above, On the condition that the time from the start of transmission is within the transmission allocation time T1, the fire telegram is retransmitted to the radio wave repeater 14-1 with the changed transmission power P2 = 100 mW.

  On the other hand, when the wireless sensor 16-11 cannot receive the ACK, the transmission power P2 = 100 mW is changed to a larger transmission power P3 = 1000 mW, and the time from the start of the first transmission is the transmission allocation time T1. If it is within the range, the fire telegram is retransmitted to the radio wave repeater 14-1 with the changed transmission power P3 = 1000 mW.

  When the radio wave repeater 14-1 receives a message from the wireless sensor 16-11, the radio wave repeater 14-1 compares the message transmission source ID with the registered node ID, and an effective message when the two match. As shown in the communication path 15b to the wireless reception repeater 12-1.

  The relay transmission of the radio wave repeater 14-1 is transmitted to the wireless reception repeater 12-1 with the initially set transmission power P1 = 10 mW, and is switched to the reception operation when the transmission is finished.

  After performing the continuous transmission of the fire telegram, the radio wave repeater 14-1 normally ends the transmission operation when receiving the ACK from the wireless reception repeater 12-1, but if the ACK is not received, On the condition that the time from the start of the first transmission is within the transmission allocation time T1, the initially set transmission power P1 = 10 mW is changed to, for example, the next largest transmission power P2 = 100 mW in Table 1 and is re-executed. If the ACK is still not received, the transmission power is changed to a larger transmission power P3 = 1000 mW and retransmitted.

  When the wireless reception repeater 12-1 receives a fire message from the radio repeater 14-1 assigned as a child node, the wireless reception repeater 12-1 compares the fire message transmission source ID with the registered node ID, When the two match, the message is received and processed, and a fire alarm signal is transmitted to the P-type receiver 10 by supplying a alarm current as a contact output to the sensor line 18-1.

  In addition, when the wireless reception repeater 12-1 receives a fire message from the wireless sensors 16-13 and 16-14 in which the node ID is registered as a child node, the wireless transmission repeater 12-1 adds the transmission source ID of the received message. Compared with the registered node ID, the received message is processed as a valid message when the two match, and a fire alarm signal is sent to the P-type receiver 10 as a contact output for the sensor line 18-1. Send.

  The transmission operation of the wireless sensors 16-13 and 16-14 in the parent-child relationship to the wireless reception repeater 12-1 is also performed by the wireless sensors 16-11 and 16 in the parent-child relationship with the radio wave relay 14-1. −12, for example, the wireless sensor 16-13 transmits the fire telegram to the wireless reception repeater 12-1 with the initial transmission power P1 = 10 mW, and the wireless reception relay 12 When the ACK is received from -1, the transmission operation is normally terminated. However, when the ACK is not received, the initial setting is performed on the condition that the time from the first transmission start is within the transmission allocation time T1. For example, if the transmission power P1 = 10 mW is changed to the next largest transmission power P2 = 100 mW in Table 1 and retransmitted, and ACK is not received yet, the transmission power P3 = 1000 mW is increased. Further to be retransmitted.

  Further, the wireless reception repeater 12-1 is additionally registered with the transmission source ID of the received message even when the message is directly received from the wireless sensors 16-11 and 16-12 which are not assigned. Compared with the node ID, if both match, the message is processed as a valid message, and the processing result is transmitted to the P-type receiver 10.

  The operation of transmitting a fire telegram by the wireless sensor 16 and the radio repeater 14 is the same for other telegrams such as a fire recovery telegram and a periodic notification telegram. However, increasing the transmission power affects the battery life of the wireless sensor 16 and the radio repeater 14, so the relatively important fire recovery message may be the same, but the periodic report, failure, test, For a low importance message used for system management such as activation, it is desirable to fix the initially set transmission power P = 10 mW or limit the upper limit of the transmission power to be changed to P2 = 100 mW.

  Here, the periodic notification message is used to monitor that the radio wave repeater 14 and the wireless sensor 16 are operating normally, i.e., that no carry-out or battery exhaustion has occurred. The sensor 16 transmits periodically. In response to the transmission of the periodic notification message from the wireless sensor 16 and the radio wave repeater 14, the wireless reception repeater 12 receives and registers as a valid message when the message transmission source ID matches the registered node ID. The periodic notification timer provided for each node ID is reset and started.

  However, if the periodic notification timer expires beyond the specified time without receiving periodic periodic notification messages, it is determined that the periodic notification is abnormal because the node is suspected of not operating normally. Then, the failure occurrence is notified to the P-type receiver 10. This failure occurrence notification notifies, for example, the occurrence of failure due to abnormal periodic notification by disconnecting the terminal resistance connected to the sensor line 18 from the P-type receiver 10 to create a pseudo disconnection state.

[Configuration of wireless sensor]
(Outline of wireless sensor)
FIG. 2 is a block diagram showing an outline of the functional configuration of the 1F wireless sensor 16-11 provided in FIG. The same applies to the other wireless sensors 16-12 to 16-34.

  As shown in FIG. 2, the wireless sensor 16-11 functioning as a sensor node includes a sensor control unit 20, a wireless communication unit 22, an antenna 24, a sensor unit 26, and an operation unit 28 such as a test / registration switch. And a battery 30.

  The sensor unit 26 is a temperature detection unit or a smoke detection unit (smoke detection unit). When a temperature detection unit is provided as the sensor unit 26, for example, a thermistor is used as the temperature detection element. In this case, a voltage detection signal corresponding to a change in resistance value due to temperature is output to the sensor control unit 20. In addition, when the smoke detector is provided as the sensor unit 26, the light emitter having a known scattered light type smoke detector structure is intermittently driven to emit light at a predetermined cycle according to an instruction from the sensor controller 20. The light receiving signal of the scattered light received by the light receiving unit such as a photodiode is amplified and a detection signal corresponding to the smoke density is output to the sensor control unit 20.

  The sensor control unit 20 has a function realized by executing a program, for example. As the hardware, a CPU, a memory, a computer circuit having various input / output ports, and the like are used.

(Configuration of wireless communication unit)
The wireless communication unit 22 includes a communication control unit 32, a transmission unit 34, and a reception unit 36, and is known as STD-30 (a wireless facility standard for a low power security system wireless station), which is known as a standard for a specific low power wireless station for security. 426 MHz band radio signal (telegram), which is a standard).

  The communication control unit 32 is a function realized by executing a program, for example, using a computer circuit having a CPU, a memory, various input / output ports and the like as hardware.

  The transmission unit 34 performs radio transmission without performing carrier sense by setting the antenna power to 1 W or less and using a radio wave having a frequency of 426.250 MHz or more and 426.8375 MHz or less.

  In accordance with the standard of STD-30, the communication control unit 32 instructs the transmission unit 34 to transmit a transmission from the start of transmission of the message until the transmission suspension is required (for example, T1 = 2 seconds). As shown in Fig. 5, the message is transmitted with the initially set transmission power P1 = 10 mW, and when the transmission is completed, the reception unit 36 is switched to the reception state. When ACK is received in this state, the transmission ends normally, while Is not received, until the ACK can be received during the remaining time of the transmission allocation time T1, for example, the transmission power is repeatedly retransmitted while gradually increasing the transmission power to P2 = 100 mW and P3 = 1000 mW. .

  In addition, the communication control unit 32 instructs the transmission unit 34 to repeat transmission while increasing transmission power, and when the transmission allocation time T1 = 2 seconds is reached, transmission is performed even during the transmission. After the transmission suspension time T2 = 2 seconds has elapsed, similar transmission is repeated, and control is performed to terminate transmission abnormally when a predetermined number of retries, for example, seven, is reached.

(Configuration of sensor control unit)
The sensor control unit 20 compares, for example, a smoke concentration detection signal output from the sensor unit 26 with a predetermined threshold, determines that a fire has occurred when the threshold is exceeded, and instructs the wireless communication unit 22 to send a fire message. Control to send.

  In addition, the sensor control unit 20 may recover the fire (for example, if the smoke concentration detection signal output from the sensor unit 26 falls below the threshold value for a predetermined time, for example, or continues for a predetermined number of times) Control to send a fire recovery message to the wireless communication unit 22.

  In addition, the sensor control unit 20 performs a control to instruct the wireless communication unit 22 to periodically report and transmit a periodic notification message.

  In addition, when detecting the registration mode set by the operation unit 28, the sensor control unit 20 generates an activation message or a test message in which a node ID known as a device ID is set as a transmission source ID, and the wireless communication unit 22 Is instructed to transmit a periodic report, and the node ID is registered in the radio wave repeater 14-1.

[Configuration of radio wave repeater]
(Outline of radio repeater)
FIG. 3 is a block diagram schematically showing the functional configuration of the 1F radio wave repeater 14-1 provided in FIG. The other radio wave repeaters 14-2 and 14-3 have the same configuration.

  As shown in FIG. 3, the radio wave repeater 14-1 functioning as a relay node includes a relay control unit 38, a wireless communication unit 40, an antenna 42, an operation unit 44, a display unit 46, a memory 48, and a battery 50. .

  The relay control unit 38 is a function realized by, for example, execution of a program, and uses, as hardware, a computer circuit including a CPU, a memory 48, various input / output ports, and the like. In addition, a relay control table 58 is provided in the memory 48, and as shown in FIG. 1, the node IDs of the wireless sensors 16-11 and 16-12 assigned as child nodes to the radio wave repeater 14-1 are registered. ing.

  The battery 50 may be a power source unit that receives commercial AC 100 volts and converts it to a DC power source.

(Configuration of wireless communication unit)
The wireless communication unit 40 includes a communication control unit 52, a transmission unit 54, and a reception unit 56, and is known as STD-30 (a wireless facility standard for a low power security system wireless station), which is known as a standard for a specific low power wireless station for security. 426MHz band telegram, which is a standard).

  The transmission unit 54 and the reception unit 56 provided in the wireless communication unit 40 are basically the same as those of the transmission unit 34 and the reception unit 36 provided in the wireless communication unit 22 in FIG. .

  For example, as shown in Table 1, the communication control unit 52 relays a message with the initially set transmission power P1 = 10 mW, switches the reception unit 56 to the reception state at the end of transmission, and receives the ACK in this state. In this case, relay transmission is normally terminated. On the other hand, if ACK cannot be received, transmission power is stepwise, for example, P2 = 100 mW and P3 = 1000 mW until ACK can be received during the remaining time of transmission allocation time T1. Control to repeat relay and retransmission of messages while increasing.

  Further, the communication control unit 52 instructs the transmission unit 54 to repeat the relay retransmission while increasing the transmission power, and when the transmission allocation time T1 = 2 seconds is reached, After the transmission is stopped and the transmission suspension time T2 = 2 seconds has passed, similar relay retransmission is repeated, and control is performed to terminate transmission abnormally when a predetermined number of retries, for example, seven, is reached.

  Further, when receiving an ACK instruction from the relay control unit 38 based on the message reception, the communication control unit 52 performs control to transmit ACK with the initially set transmission power.

(Configuration of relay control unit)
The relay control unit 38 performs relay control as a control function realized by executing the program.

  When the relay control unit 38 receives a fire message, a fire recovery message, or a periodic notification message transmitted from the wireless sensor via the wireless communication unit 40, the relay control unit 38 acquires a transmission source ID included in each message, Compared with the node ID registered in the relay control table 58, if both match, the wireless communication unit 40 is instructed to transmit an ACK and subsequently control the relayed transmission of the received message. If they do not match, relay transmission is not performed.

  In addition, the relay control unit 38 periodically instructs the wireless communication unit 40 to make a periodic report and performs control to transmit a periodic report message.

[Configuration of radio reception repeater]
(Overview of repeater for wireless reception)
FIG. 4 is a block diagram showing an outline of the functional configuration together with a P-type receiver, which is taken out of the radio reception repeater 12-1 functioning as a 1F disaster prevention radio node provided in FIG. The same applies to the other radio reception repeaters 12-2 and 12-3.

  The wireless reception repeater 12-1 includes a reception relay control unit 60, a wireless communication unit 62, an antenna 64, a wired communication unit 75, an operation unit 66, a display unit 68, a memory 70, and a power supply unit 72.

  The reception relay control unit 60 is a function realized by executing a program, for example. As hardware, a CPU, a memory 70, a computer circuit having various input / output ports, and the like are used. The memory 70 is provided with a relay control table 80. As shown in FIG. 1, the wireless sensors 16-13 and 16-14 assigned to the wireless reception repeater 16-1 as child nodes and radio wave repeaters. The node ID of 14-1 is registered, and the node IDs of the wireless sensors 16-11 and 16-12 that usually send and receive wireless signals via the radio wave repeater 14 are additionally registered.

As shown in FIG. 1, the power supply unit 72 is supplied with DC power from the P-type receiver 10 through the power line 15. However, the power supply unit 72 may generate DC power by converting DC power from commercial AC 100 volts. However, a battery power source may be adopted.

(Configuration of wireless communication unit)
The wireless communication unit 62 includes a communication control unit 74, a transmission unit 76, and a reception unit 78, and is known as STD-30 (a wireless facility standard for a low power security system wireless station), which is known as a standard for a specific low power wireless station for security. 426MHz band telegram, which is a standard).

  The communication control unit 74, the transmission unit 76, and the reception unit 78 provided in the wireless communication unit 62, except that the transmission power is fixedly set, the communication control unit 32 and the transmission unit provided in the wireless communication unit 22 in FIG. Since the configuration is basically the same as that of the reception unit 36, the description thereof is omitted.

(Configuration of reception relay control unit)
When receiving the fire message via the wireless communication unit 62, the reception relay control unit 60 compares the transmission source ID included in this message with the node ID registered and additionally registered in the relay control table 80, and If the two match, the wireless communication unit 62 is instructed to transmit an ACK, and the wired communication unit 75 is instructed to cause a fire alarm signal by a contact output operation that causes a notification current to flow through the sensor line 18-1. Is transmitted to the P-type receiver 10.

  In addition, when the reception relay control unit 60 receives a fire recovery message via the wireless communication unit 62 after transmitting the fire alarm signal to the P-type receiver 10, the transmission source ID and relay control included in the message are transmitted. The node IDs registered and additionally registered in the table 80 are compared, and if they match, the wireless communication unit 62 is instructed to transmit ACK, and the wired communication unit 75 is instructed to detect the sensor line. The contact output operation for causing the alarm current to flow through 18-1 is canceled, and the transmission of the fire notification signal to the P-type receiver 10 is stopped.

  Further, when receiving the periodic notification message via the wireless communication unit 62, the reception relay control unit 60 obtains the transmission source ID included in the message and the node ID registered and additionally registered in the relay control table 80. When the two match, the wireless communication unit 62 is instructed to transmit ACK, and the periodic notification timer provided for each node ID is reset and started, and the periodic notification message is not received. If the timer expires beyond the predetermined time, the terminator error is detected by disconnecting the terminating resistor connected to the sensor line 18-1 from the P-type receiver 10 and creating a pseudo disconnection state. Control to notify the occurrence of failure due to detection.

[Configuration of P-type receiver]
In FIG. 4, the P-type receiver 10 includes a reception control unit 82, line reception units 84-1 to 84-3, a power supply unit 86, a display unit 88, an acoustic alarm unit 90, an operation unit 92, a transfer unit 94, and A nonvolatile memory 96 is provided. In addition, the operation power supply uses the commercial power supply appropriately backed up (not shown).

  As shown in FIG. 1, the sensor lines 18-1 to 18-3 are drawn from the line receiving units 84-1 to 84-3, respectively, and the wireless reception repeater 12-1 is connected to the sensor line 18-1. Is connected.

  The line receiving unit 84-1 detects the alarm current that flows through the contact operation by the wired communication unit 75 provided in the wireless reception repeater 12-1 and outputs a fire detection signal to the reception control unit 82. In addition, the line receiving unit 84-1 regards the disconnection of the termination resistor based on the detection of the periodic notification abnormality in the wired communication unit 75 of the wireless reception repeater 12-1 as the monitoring current interruption due to the disconnection of the sensor line. And a failure detection signal is output to the reception control unit 82.

  The reception control unit 82 is a computer circuit having a CPU, a ROM, a RAM, an AD conversion port, and various input / output ports, and the functions of the reception control unit 82 are realized by executing a program by the CPU.

  When the reception output of the fire alarm signal is obtained by detection of the alarm current by any of the line receivers 84-1 to 84-3, the reception controller 82 determines that the corresponding sensor line is fire alarm, A representative fire display is displayed on the display unit 88, and a fire occurrence area is displayed by a line display for each line. Also, an acoustic fire alarm is output from the acoustic alarm unit 90.

  In addition, when the reception control unit 82 detects disconnection of the sensor lines 18-1 to 18-3 by the line reception units 84-1 to 84-3, the reception control unit 82 displays a representative failure on the display unit 88 and generates a failure. The district is displayed for each line, and an acoustic failure alarm is output from the acoustic alarm unit 90.

[Message format]
FIG. 5 is an explanatory diagram showing a message format transmitted and received by the wireless disaster prevention system of FIG.

  As shown in FIG. 5, the message format includes a phase correction signal, a serial number, a transmission source ID, a data code, and an error check code. The phase correction signal is a preamble signal that repeats with a predetermined bit length of “101010... 10”, thereby making it possible to prepare for reception by phase synchronization of a reception PLL provided in the wireless communication unit.

  The serial number stores a value that changes in order in the range of 0 to 255 for each transmission of the message, and the receiving side can know the order of the message transmission. In the transmission source ID, the node ID of the device that is the transmission source is set.

  The data code is information indicating the contents of the message, and a predetermined code indicating the contents of fire, fire recovery, periodic notification, failure, activation, test, ACK, etc. is set.

  The wireless sensor 16, the radio wave repeater 14, and the wireless reception repeater 12 provided in the wireless disaster prevention system of FIG. 1 generate a message according to this message format when a transmission request is generated, and transmit once. The same message is transmitted, for example, four times in succession.

[Transmission operation]
FIG. 6 is a time chart showing a transmission operation when a fire is detected by a wireless sensor, FIG. 6 (A) shows a fire detection, FIG. 6 (B) shows a transmission standard, and FIG. ) Shows transmission at normal transmission and ACK reception, FIG. 6D shows transmission and ACK reception when a communication failure occurs, and FIG. 6E shows a change in transmission power. Note that the time width of the transmission allocation time T1 in FIG. 6 does not match the scale of the time width of the transmission suspension period T2 in order to secure a space for writing the messages in FIGS. 6 (C) and 6 (D).

  In FIG. 6, if the wireless sensor 16 detects a fire at time t1, the fire message generated based on the fire detection at time t1 is continuously transmitted four times at the initial setting of transmission power P1 = 10 mW. Transmits and switches to the reception state when transmission ends. When the fire telegram transmitted by the wireless sensor 16 is normally received by the radio wave repeater 14, for example, an ACK is transmitted, and the transmission is normally terminated by receiving this ACK.

  On the other hand, if a communication failure occurs and an ACK is not received at the timing indicated by the dotted line even when switching to the reception state with respect to the transmission of the fire telegram with the initial transmission power P1 = 10 mW from time t1, the initial setting If the transmitted power P1 = 10 mW is changed to the next largest transmission power P2 = 100 mW and the fire message is retransmitted. If the ACK is still not received, the maximum transmission power P3 is changed to 1000 mW and the fire message is retransmitted. To do. In this case, if the communication failure is temporary, an ACK is received for the transmission of the fire message with the second transmission power P2 = 100 mW or the retransmission of the fire message with the third transmission power P3 = 1000 mW. Can be terminated normally.

  FIG. 6D illustrates an extreme case where ACK cannot be received even if retransmission is repeated, and the transmission power P3 is changed to 1000 mW and the fire message is repeatedly transmitted without receiving ACK. When the transmission allocation time T1 = 2 seconds elapses at the time t2, the transmission is terminated, the transmission pause time T2 = 2 seconds, the retransmission is repeated from the time t3, and the number of retransmission retries is a predetermined number, for example, 7 times If ACK is still not received, the transmission operation is terminated abnormally as retry over. Such a retry over is assumed, for example, when the transmission destination radio relay 14 is out of order.

[Modification of the present invention]
(Wireless disaster prevention system)
In the above embodiment, a wireless disaster prevention system is configured by a wireless sensor, a radio wave repeater, a wireless reception repeater, and a receiver, but a relatively short communication distance range that can communicate with the wireless reception repeater. If a wireless sensor is installed, a wireless disaster prevention system may be configured with the wireless sensor, the wireless reception repeater, and the receiver, except for the radio wave repeater. The radio reception repeater and the receiver may be integrated.

  Further, in the above embodiment, wirelessly from the wireless sensor to the radio repeater, from the radio wave relay to the radio reception repeater, or from the wireless sensor to the radio reception repeater, from the child node to the parent node. However, the present invention can also be applied to a system in which wireless signals are transmitted and received between wireless fire detectors. When sending a signal to the previous sensor, if the ACK signal is not possible, the transmission power may be changed.

(R type receiver)
In the above embodiment, a wireless reception repeater is connected to a sensor line from a P-type receiver as a fire receiver, but a wireless reception repeater is connected to an R-type receiver having a data transmission function. You may do it.

(Control part)
In the above embodiment, the wireless sensor 16, the radio wave repeater 14, and the wireless reception repeater 12 are provided with a sensor control unit, a relay control unit, and a reception relay control unit separately from the communication control unit of the wireless relay unit. However, both may be used as one control unit.

In the embodiment of FIG. 6, the transmission power is changed when four transmissions are completed and ACK cannot be received, but the initial transmission allocation time T1 is the initially set transmission power P1 = 10 mW. When the ACK cannot be received even after the first transmission allocation time T1 has elapsed, the transmission power P2 is changed to the next largest transmission power P2 = 100 mW at the next transmission allocation time T1 and retransmitted. The transmission power may be varied for each transmission allocation time T1. When transmitting a radio signal, the current transmission power stage information may be added and transmitted to the parent node so that the parent node side can recognize the radio wave condition. The parent node having received the information of the transmission power step, the reply ACK, when in accordance with the transmission power step information from the child node, changing the transmission power may be returned, bad radio wave condition, the ACK Since there is a possibility that the radio wave condition may be poor in the transmission of, transmission may be performed with a higher transmission power, and control may be performed so that the response signal is reliably received by the child node.

(Other)
The present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

12-1 to 12-3: Radio reception repeaters 14-1 to 14-3: Radio wave repeaters 16-11 to 16-34: Wireless sensors 18-1 to 18-3: Sensor line 20: Sensing Controllers 22, 40, 62: Wireless communication units 24, 42, 64: Antenna 26: Sensor units 32, 52, 74: Communication control units 34, 54, 76: Transmission units 36, 56, 78: Reception unit 38: Relay control unit 60: Reception relay control unit 82: Reception control unit

Claims (2)

Based on a communication scheme that requires a predetermined transmission suspension time following a predetermined transmission allocation time, a radio signal is transmitted and received between the child node and the parent node, and a radio signal is transmitted from the child node during the transmission allocation time. In the wireless disaster prevention system that can transmit intermittently,
When the child node does not receive a confirmation response radio signal from the parent node after transmitting a radio signal including transmission power information of the predetermined transmission power with a predetermined transmission power within the transmission allocation time. The wireless transmission includes the transmission power information of the increased transmission power by gradually increasing the predetermined transmission power until the acknowledgment radio signal is received during the remaining time of the transmission allocation time. A wireless disaster prevention system that repeats signal retransmission.
Based on a communication scheme that requires a predetermined transmission suspension time following a predetermined transmission allocation time, a radio signal is transmitted and received between the child node and the parent node, and a radio signal is transmitted from the child node during the transmission allocation time. In a disaster prevention radio system that can transmit intermittently,
When the child node does not receive a confirmation response radio signal from the parent node after transmitting a radio signal including transmission power information of the predetermined transmission power with a predetermined transmission power within the transmission allocation time. The wireless transmission includes the transmission power information of the increased transmission power by gradually increasing the predetermined transmission power until the acknowledgment radio signal is received during the remaining time of the transmission allocation time. Just repeat the re-transmission of the signal,
The radio disaster prevention system, wherein the parent node transmits a radio signal of the confirmation response by changing transmission power according to transmission power information included in the received radio signal.

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