JP2011118798A - Radio disaster prevention system and sensor node - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately perform event corresponding processing by suppressing the time delay to a requisite minimum when a non-urgent event occurs during telegram transmission. <P>SOLUTION: In occurrence of an event A, a transmission processing part of a radio sensor repeats, twice or more, telegram transmission A1-A3 for continuously transmitting the same telegram signal for a predetermined time T1 and telegram pause for pausing the telegram transmission for a predetermined time T2. When a non-urgent event B requiring no urgent processing occurs during repetition of the telegram transmission A1 and A2 and the telegram pause based on occurrence of the preceding event A by the transmission processing part, a transmission switching part repeats, twice, the telegram transmission A1 and A2 and the telegram pause based on the preceding event and pauses them, then switches them to the repetition of the telegram transmission B1, B2, etc. and the telegram pause based on the non-urgent event B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a wireless disaster prevention system and a sensor node that transmit a wirelessly transmitted message from a sensor node such as a wireless sensor to a receiver and make an alarm.

  Conventionally, in a wireless disaster prevention monitoring system that monitors fires, when multiple wireless fire detectors are installed as sensor nodes in a warning area such as each floor of a building and a fire is detected by the wireless sensor Then, a message indicating a fire is wirelessly transmitted to a wireless reception repeater as a wireless 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.

  In the case of a wireless disaster prevention system, when the distance between the wireless sensor and the wireless reception repeater is long and it is expected that the radio wave will be difficult to reach, the electromagnetic wave is between the wireless sensor and the wireless reception relay. A repeater can be installed to relay radio waves. In addition, when a radio reception repeater and a wireless sensor are actually installed at the time of construction and the radio wave condition is bad, a radio wave repeater can be additionally installed later. By operating the radio wave repeater with a battery, the wiring of the power supply line is unnecessary, and the radio wave repeater can be easily installed. In this way, when the radio wave repeater is operated by a battery, the battery life is shortened if the continuous reception operation is performed. Therefore, the electronic message is intermittently received.

In this intermittent reception, when a fire is detected by a wireless sensor, a message is transmitted over a predetermined transmission time. On the other hand, the receiving side performs carrier sense in a cycle shorter than the transmission time. Since at least one carrier sense is performed during this period, even in asynchronous communication, a message can be reliably received by intermittent reception.

JP 2008-004033 A JP 2001-290209 A

  However, in the intermittent reception in such a conventional wireless disaster prevention system, the carrier sense cycle for intermittent reception is set so as to be shorter than the transmission time, so the carrier sense operation on the receiver side is short. When the operation is performed by a cycle and the operation is performed by a battery, there is a problem that current consumption increases and the battery life is reduced.

  In order to solve this problem, it is possible to lengthen the message transmission time when a fire is detected, and lengthen the carrier sense period to be set shorter than that. There is a problem that the fire response time until the transmission is determined and the carrier sense cycle of intermittent reception cannot be increased unnecessarily.

  In order to solve this problem, the inventor of the present application, when an event such as a fire detection in a wireless sensor occurs, a message transmission that continuously transmits the same message signal over a predetermined message transmission time, and a predetermined time In the radio wave repeater, at least one of two consecutive message transmissions with a message pause from the wireless sensor has a reception timing. A wireless disaster prevention system has been proposed in which a carrier sense period is set to enter and a transmission message from a wireless sensor is intermittently received.

  According to this wireless disaster prevention system, carrier sense operation is performed at a cycle longer than the message transmission time, power consumption due to carrier sense is reduced, and battery life can be extended when operated by a battery.

  However, in such a system in which the carrier sense period is longer than the message transmission time, a certain event occurs and the process is not as urgent as a fire detection during transmission by repeating message transmission and transmission suspension. If an urgent event occurs, for example, a failure event or a switch operation event occurs, the transmission of the urgent event starts after the preceding event message transmission ends. There is a problem in that it takes time to be received by the wireless reception repeater via the repeater and further sent to the receiver for notification.

An object of the present invention is to provide a wireless disaster prevention system and a sensor node capable of appropriately performing event response processing while minimizing the time delay when an emergency event occurs during message transmission. And

(system)
The present invention is composed of a sensor node, a radio relay node, a radio disaster prevention node, and a receiver, and a telegram signal transmitted from the sensor node or a telegram signal transmitted from the sensor node via the radio relay node is transmitted by the radio disaster prevention node. In the wireless disaster prevention system that receives and processes, and transmits the processing result to the receiver connected by the signal line,
The sensor node
A transmission processing unit that repeats at least two times a message transmission that continuously transmits the same message signal over a predetermined message transmission time and a message pause that pauses the message transmission for a predetermined time when an event occurs;
If there is an urgent event that is not urgent, during the transmission less than two times of message transmission and message suspension based on the preceding event occurrence by the transmission processing unit, message transmission and message suspension based on the preceding event twice After repeatedly canceling, a transmission switching unit that switches between message transmission based on an urgent event and message suspension,
With
The radio wave relay node includes an intermittent receiving unit that receives intermittently so that a reception timing enters at least one of two continuous message transmissions with a message pause.

  Here, the emergency event that occurs in the sensor node includes an operation event such as a switch operation, a failure event, and a periodic notification event.

  The transmission processing unit of the sensor node arranges a predetermined random pause time randomly set for each node after repeating the message transmission and the message pause three times as a transmission pattern to be transmitted when the event occurs, and after the random pause time The message transmission and message suspension are repeated three times.

The intermittent receiver of the radio relay node
A carrier sense cycle setting unit for setting a carrier sense cycle when performing carrier sense twice so that a predetermined carrier sense required time overlaps either of two continuous message transmission times with a message pause time in between;
An intermittent reception unit that detects the presence or absence of a carrier of a telegram signal for each carrier sense cycle and processes a telegram received when the carrier detection state continues for a carrier sense essential time or more,
With
The carrier sense cycle setting unit
The message transmission time is T1, the message suspension time is T2, the reception start possible time obtained by subtracting the minimum required carrier sense time T5 required for the reception operation from the message transmission time T1 is set to T3 and the message suspension time T2, and the required carrier sense time T5 When T4 is the reception start impossible time after adding
The reception start possible time is T3 and the reception start impossible time T4 (T3 × 2) / (T3 × 2 + T4) ≧ 1/2
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 2 + T4) / 2 ≧ Tcs ≧ T4
Set to a value in the range.

(Sensor node)
In the present invention, when an event occurs, a telegram signal is transmitted to a radio relay node that receives intermittently so that a reception timing is included in at least one of two telegram transmissions that are a predetermined time with a telegram pause for a predetermined time. In the sensor node,
A transmission processing unit that repeats at least two times a message transmission that continuously transmits the same message signal over a predetermined message transmission time and a message pause that pauses the message transmission for a predetermined time when an event occurs;
If there is an urgent event that is not urgent, during the transmission less than two times of message transmission and message suspension based on the preceding event occurrence by the transmission processing unit, message transmission and message suspension based on the preceding event twice After repeatedly canceling, a transmission switching unit that switches between message transmission based on an urgent event and message suspension,
Is provided.

According to the present invention, when another urgent event occurs during transmission based on the preceding event in the sensor node, when the two message transmissions with the message pause necessary for intermittent reception of the message are terminated. Since the message transmission based on the preceding event was canceled and switched to the message transmission based on the non-urgent event, the intermittent reception for the message transmission of the preceding event was not impaired, and it was based on the urgent event that followed in the minimum necessary time. It is possible to switch to message transmission, and it is possible to shorten the time until an emergency event is reported from the sensor node to the receiver via the radio relay node and the wireless disaster prevention node. For example, for a communication test of the sensor node If a message is sent based on an urgent event by operating the switch, even if a message is being sent based on a preceding event, Results corresponding to the test message in the receiver can receive, can be efficient test work.

Explanatory drawing which showed embodiment of the wireless disaster prevention system by this invention Explanatory drawing which showed the message format of the radio signal transmitted and received by the radio disaster prevention system of FIG. The block diagram which showed the detail of the wireless sensor and radio wave repeater of FIG. The block diagram which showed the detail of the repeater for radio | wireless reception of FIG. 1, and a P-type receiver Time chart showing intermittent message transmission by wireless sensor Time chart showing the intermittent reception processing by the radio wave repeater of FIG. 3 that effectively receives two transmission messages Time chart showing the case of effectively receiving the second transmission message in the intermittent reception of FIG. Time chart showing message transmission according to the present embodiment when an urgent event occurs during message transmission based on the preceding event Time chart showing the problem when the message transmission according to this embodiment is not performed as shown in FIG. The flowchart which showed the sensor process by the wireless sensor of FIG. The flowchart which showed the electric wave relay process by the electric wave repeater of FIG. The flowchart which showed the relay process for radio | wireless reception by the radio | wireless receiver repeater of FIG.

  FIG. 1 is an explanatory view showing an embodiment of a wireless disaster prevention system according to the present invention. In FIG. 1, wireless reception repeaters 12-1 to 12-3 functioning as wireless disaster prevention nodes are installed on the floors 1F to 3F of a building 11 to be monitored, and a P-type receiver 10 which is a fire receiver. Are connected to sensor lines 18-1 to 18-3 drawn from floor to floor.

  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. Further, in the present embodiment, the radio wave repeater 14 is used to prevent the radio reception repeaters 12-1 to 12-3 from reaching non-reachable signals due to the attenuation of radio waves from the radio sensors that are separated from each other. -1 to 14-3 are installed.

  In each of the wireless sensors 16-11 to 16-34 and the radio wave repeaters 14-1 to 14-3, unique node IDs using device IDs are registered in advance.

  The wireless sensors 16-11 to 16-14 determine that a fire event has occurred when the smoke concentration or temperature due to fire exceeds a predetermined threshold, and send a telegram signal indicating fire (hereinafter simply referred to as "telegram"). Intermittent wireless transmission.

  In this intermittent transmission, for example, the same telegram data is transmitted 18 times continuously for a predetermined transmission time T1, and is repeated three times with a predetermined transmission pause time T2, and then the transmission is unique to the wireless sensor. The transmission operation of transmitting the same message data 18 times continuously over the predetermined transmission time T1 is repeated three times with the predetermined transmission pause time T2 in the same manner, with one random pause time T6. The transmission operation is as follows.

  The wireless sensors 16-11 to 16-14 also perform a set of message transmission operations when detecting the occurrence of a test event due to a switch operation or a failure event such as a sensor failure. Such a test event, a failure event, etc. can be said to be an urgent event in which processing is not urgent with respect to a fire event that needs to be urgently reported to the receiver side and processed.

  In the present embodiment, when an occurrence of an emergency event is detected during a set of transmission operations based on the occurrence of a preceding event, the emergency event is sent to the receiver as quickly as possible. In order to perform the necessary processing, when the transmission operation necessary for intermittent reception of the preceding message is completed, the transmission is switched to the message transmission based on the subsequent urgent event, and the details will be clarified in the later explanation. .

  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.

  The same applies to the 2F and 3F wireless reception repeaters 12-2 and 12-3 and the radio wave repeaters 14-2 and 14-3, and the wireless reception repeater 12-2 includes the wireless sensor 16-. 23, 16-24 and the node IDs of the radio repeaters 14-2 are registered in advance, and the radio repeater 14-2 registers the node IDs of the wireless sensors 16-21 and 16-22, and the radio reception repeaters 12-3 registers the node IDs of the wireless sensors 16-33 and 16-34 and the radio relay 14-3, and the radio relay 14-3 stores the node IDs of the wireless sensors 16-31 and 16-32. Is registered.

  When a telegram is received by registering the node ID for the radio reception repeater 12-1 and the radio repeater 14-1, the transmission source ID included in the telegram is compared with the node ID registered in advance. For example, when both match, it is processed as a valid message.

  Furthermore, in the present embodiment, the wireless reception repeater 12-1 receives directly from the wireless sensors 16-11 and 16-12 that are not in a parent-child relationship without going through the radio wave repeater 14-1. In order to enable processing as a valid electronic message, the registered node ID is transferred from the radio wave repeater 14-1 to the wireless reception repeater 12-1, and is additionally registered. Even when a message is received directly from the wireless sensors 16-11 and 16-12 that are not assigned as child nodes in the device 12-1, a match with the additionally registered node ID is determined and a valid message is received. Can be processed as.

  The radio repeater 14-1 performs intermittent reception. In this intermittent reception, the presence or absence of a telegram carrier transmitted from the wireless sensors 16-11 and 16-12 is detected every predetermined carrier sense period Tcs, and when a carrier is detected, a reception operation is performed. The carrier sense period Tcs is determined so that a message can be received effectively in one of two transmission times T1 with a transmission pause time T2 transmitted from the wireless sensors 16-11 and 16-12 in between. ing. The details of this carrier sense period Tcs will be clarified in later explanation.

  When the radio wave repeater 14-1 receives a message from the wireless sensors 16-11 and 16-12 by intermittent reception, the radio wave repeater 14-1 compares the transmission source ID of the message with the registered node ID. When they match, they are relayed and transmitted to the wireless reception repeater 12-1 as an effective message. The transmission of the relay message from the radio wave repeater 14-1 repeats the transmission operation of transmitting the same message data, for example, four times continuously over a predetermined transmission time, three times with a predetermined transmission pause time.

  The wireless reception repeater 12-1 is always in a receiving state, and when receiving a message from the wireless sensors 16-13 and 16-14 assigned as child nodes, The registered node ID is compared, and when both match, the received message is processed as valid, and the processing result is transmitted to the P-type receiver 10.

  When the received electronic message is a message indicating a fire from the wireless sensor, the wireless reception repeater 12-1 sends a notification current as a contact output to the sensor line 18-1 to the P-type receiver 10. A fire alarm signal is transmitted by flowing.

  The wireless reception repeater 12-1 is registered in advance with the transmission source ID included in the electronic message even when the electronic message is received from the wireless sensors 16-11 and 16-12 via the radio wave repeater 14-1. The received message is received as a valid message by matching the received node ID, and the reception result is transmitted to the P-type receiver 10.

  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.

  In the present embodiment, it is monitored that the radio wave repeater 14-1 and the wireless sensors 16-11 to 16-14 are operating normally, i.e., no carry-out or battery exhaustion has occurred. Therefore, each of the nodes periodically transmits a periodic notification message.

  In response to the transmission of the periodic notification message from the wireless sensors 16-11 to 16-14 and the radio wave repeater 14-1, the wireless reception repeater 12-1 matches the node ID registered with the transmission source ID of the message. When the message is received as a valid message, the periodic notification timer provided for each registered node ID is reset and started. However, if the periodic notification timer expires after a predetermined period of time without receiving a periodic notification message, it is determined that the node is not operating properly and the periodic notification is abnormal. Notify the receiver 10 of the occurrence of a failure.

  For example, the failure occurrence notification notifies the occurrence of a failure due to abnormal periodic notification by disconnecting the terminal resistor connected to the sensor line 18-1 from the P-type receiver 10 to create a pseudo disconnection state.

  FIG. 2 is an explanatory view showing a message transmitted and received by the wireless disaster prevention system of FIG. In FIG. 2, the message format 90 includes a phase correction signal 92, a serial number 94, a transmission source ID 96, a message content 98, and an error check code 100. On the receiving side, the transmission source ID 96 is checked to determine whether the node is registered, and then the message content 98 is checked to determine the meaning of the message and processed.

  The phase correction signal 92 is a preamble signal that repeats with a predetermined bit length of “101010... 10”, whereby preparation for reception by phase synchronization of a reception PLL provided in the wireless communication unit can be performed.

  The serial number 94 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 96, the node ID of the device that is the transmission source is set. In the message content 98, fire information, failure information, and the like are set.

  FIG. 3 is a block diagram showing details of the 1F wireless sensor 16-11 and the radio relay 14-1 provided in the embodiment of FIG.

  In FIG. 3, a wireless sensor 16-11 as a sensor node includes a processor 20, a wireless communication unit 22, an antenna 24, a sensor unit 26, an operation unit 28 using a dip switch, and a battery 30. The sensor unit 26 is a temperature detection unit using, for example, a photoelectric smoke sensing unit or a thermistor.

  The processor 20 is provided with a sensor processing unit 74, a transmission processing unit 76, and a transmission switching unit 78 as functions realized by executing the program. The sensor processing unit 74 compares, for example, a smoke concentration detection signal output from the sensor unit 26 with a predetermined threshold value, determines that a fire event has occurred when the threshold value is exceeded, and wirelessly performs transmission processing based on the transmission processing unit 76. The communication unit 22 wirelessly transmits a message indicating fire from the antenna 24.

  Further, when the sensor processing unit 74 sets a registration mode by a dip switch or the like of the operation unit 28 performed immediately after the power is turned on, the sensor processing unit 74 transmits an activation message in which a node ID known as a device ID is set as a transmission source ID, and the radio wave repeater 14 -1 to register the node ID.

  Further, in addition to the fire event, the sensor processing unit 74 detects the occurrence of an event including recovery, battery exhaustion, failure, manual test, automatic test, and periodic notification, and transmission processing by the transmission processing unit 76 or transmission switching by the transmission switching unit 78 Let the process do.

  When an event occurs, the transmission processing unit 76 repeats a message transmission for continuously transmitting the same message signal for a predetermined message transmission time and a message suspension for stopping the message transmission for a predetermined time two or more times.

  That is, as shown in FIG. 5, the transmission processing unit 76 transmits, for example, transmission telegrams 110-1 to 110-3 including 18 identical telegram data 112-1 to 112-18 over a predetermined transmission time T1. The telegram transmission is repeated three times with a transmission pause in which the transmission pauses for a predetermined transmission pause time T2, followed by a random pause time T6 unique to the wireless sensor, and similarly including 18 identical telegram data. The transmission telegram 110-4 to 110-6 is repeated three times with the transmission of the transmission message over the transmission time T1 and the transmission suspension of the transmission suspension time T2, and this is set as one set of message transmission. The random pause time T6 is randomly determined based on the transmission source ID and the like, for example, in a range of 3 to 7 seconds.

  In the transmission switching unit 78, an emergency event such as a test event or a failure event that does not urgently occur occurs during the less than two repetitions of message transmission and message suspension based on the preceding event occurrence by the transmission processing unit 76. In this case, after the message transmission and the message suspension based on the preceding event are repeated twice, the message transmission and the message suspension based on the urgent event are switched.

  Referring to FIG. 3 again, the wireless communication unit 22 is provided with a transmission circuit 22a, and in the case of Japan, for example, performs wireless communication in accordance with the standard of a specific low power wireless station in the 400 MHz band. In the wireless sensor 16-11, since only a telegram is transmitted to the receiver side, no receiving circuit is provided in this embodiment.

  Further, the channel frequency of the wireless communication unit 22 uses any one of four channel frequencies f1 to f4 that can be used in the specific low power wireless station standard of the 400 MHz band. The channel frequencies may be the same on each floor in FIG. 1, or different channel frequencies may be used on adjacent floors, for example, to avoid interference.

  Next, the radio repeater 14-1 will be described. The radio wave repeater 14-1 includes a processor 32, a wireless communication unit 34 including a reception circuit 34a and a transmission circuit 34b, an antenna 35, an operation unit 36, a display unit 37, a memory 38, and a power supply unit 40. The processor 32 is provided with a carrier sense cycle setting unit 80, an intermittent reception processing unit 82, and a relay processing unit 84 as functions realized by executing the program.

  When the relay processing unit 84 starts using the radio wave repeater 14-1 by operating a registration switch provided in the operation unit 36, the relay processing unit 84 is assigned to the relay control table 85 of the memory 38 in FIG. The node IDs of the wireless sensors 16-11 and 16-12 shown are registered.

  Further, every time the relay processing unit 84 registers the assigned node IDs of the wireless sensors 16-11 and 16-12 in FIG. 1 in the relay control table 85, the relay processing unit 84 reads the registered node IDs and relays them for wireless reception. The data is transferred to the device 12-1 by a registration message, and additional registration is performed on the wireless reception repeater 12-1.

  Further, in the monitoring state after the registration of the node ID to the relay control table 85 is completed, the relay processing unit 84 intermittently receives a fire message, a periodic notification message, and the like transmitted from the wireless sensor by the wireless communication unit 34. When the message is received, the transmission source ID included in each message is acquired and compared with the node ID registered in the relay control table 85. When the two match, the received message is relayed and the mismatch is detected. In this case, relay transmission is not performed.

  When the transmission message 110-1 to 110-6 shown in FIG. 5 is transmitted from the wireless sensor 16-11, the carrier sense cycle setting unit 80, for example, performs two consecutive times with the message suspension time T2 interposed therebetween. The carrier sense cycle Tcs is set so that at least one of the message transmission times T1 of the transmission messages 110-1 and 110-2 overlaps with the minimum required carrier sense time T5 required for the reception operation.

  The intermittent reception processing unit 82 detects the presence / absence of a carrier in a transmission telegram every carrier sense cycle Tcs, and processes the telegram received when the carrier detection state continues for the carrier sense essential time T5 or more.

  The power source 40 is optimally a battery power source. The battery power supply eliminates the need for power line wiring and facilitates installation, so that the advantages of the wireless disaster prevention system can be fully utilized.

  FIG. 6 is a time chart showing the intermittent reception processing by the radio wave repeater of FIG. 3 that effectively receives two transmission telegrams in the wireless sensor 16-11 of FIG.

  FIG. 6A shows a transmission message, which shows transmission messages 110-1 and 110-2 at the beginning of one set of transmission messages, and the transmission messages 110-1 and 110-2 are the transmission time T1. There is a pause time T2 in between.

  In the present embodiment, the carrier sense period Tcs is set so that a message can be effectively received once by N = 2 times of carrier sense with respect to N = 2 times of transmitted messages 110-1 and 110-2. ing.

  The calculation method of such a carrier sense period is as follows. First, the minimum required time from the start of carrier sense until the message can be received successfully is set as a carrier sense essential time T5. The required carrier sense time T5 includes the setting time of the receiving IC that is performed after it is understood that there is a radio wave by carrier sensing, and the time required for reception of the wireless message, and depends on the specification of the receiving IC to be used and the message length. For example, T5 = 0.5 sec.

Here, if the carrier sense is not started within the time (T1-T5) obtained by subtracting the carrier sense essential time T5 from the transmission time T1 of the transmission telegrams 110-1 and 110-2, the reception cannot be performed. The time is defined as a reception start possible time T3. That is, the reception possible time T3 is
T1-T5 = T3
It becomes.

On the other hand, in the time zone in which the transmission suspension time T2 is added to the carrier sense essential time T5, since a message cannot be received, this is set as a reception start impossible time T4. The reception start impossible time T4 is
T2 + T5 = T4
It becomes.

  FIG. 6B shows reception possible states 114-1 and 114-2 determined by the reception start possible time T3 for the transmission signals 110-1 and 110-2 of FIG. 6A and reception reception determined by the reception start impossible time T4. The impossible states 116-1 and 116-2 are shown as reception enable / disable states.

First, in order to reduce the power consumption by the carrier sense operation, the carrier sense cycle Tcs is set longer than the transmission time T1 of the transmission message,
Tcs> T1 (1)
It is necessary to decide to become.

Next, since the carrier sense cycle Tcs is not longer than the reception start impossible time T4, it cannot be received by at least two carrier senses.
Tcs ≧ T4 (2)
It becomes.

  This is because if Tcs <T4, the carrier sense timing is included twice or more in the reception start impossible time T4, so that it cannot be received with two carrier senses.

Subsequently, in order to have at least two carrier sense timings before the reception start possible time T3,
Tcs ≦ (T3 × 2 + T4) / 2 (3)
It is necessary to.

However, when receiving with carrier sense twice,
{T3 × 2 / (T3 × 2 + T4)} ≧ (1/2) (4)
It must be. Since the condition of the expression (4) must be performed once during the reception start possible time T3 of the two carrier senses, the transmission impossible time T4 including the two reception start possible times T3 is interposed 2 This is because ½ or more of the times (T3 × 2 + T4) over the communication messages 110-1 and 110-2 must be the reception start possible time.

That is, when formulas (2) and (3) are put together, the carrier sense period Tcs is
T4 ≦ Tcs ≦ (T3 × 2 + T4) / 2 (5)
It becomes.

  The carrier sense period Tcs can be determined based on the above equations (1) to (5).

As a specific example, transmission time T1 = 2 sec
Transmission pause time T2 = 2sec
Carrier sense required time T5 = 0.5 sec
Receivable start time T3 = T1-T5 = 1.5 sec
Reception start impossible time T4 = T2 + T5 = 2.5 sec
In this case, it is calculated as follows.
From Equation (1), Tcs> 2 sec
From equation (2) Tcs ≧ 2.5 sec
From Equation (3), Tcs ≧ (1.5 × 2 +2.5) / 2
Tcs ≦ 2.75sec
From equation (4), 0.55 ≧ 0.5, which is also satisfied.

The carrier sense period Tcs satisfying the expressions (1), (2), and (3) is 2.5 sec ≦ Tcs ≦ 2.75 sec.
It becomes. Here, since the longer carrier sense period Tcs can reduce power consumption, it is preferable to take a longer one. For example, Tcs = 2.7 sec.

  FIG. 6C shows carrier sense timings 118-1 to 118-4 with the carrier sense period Tcs = 2.7 sec determined as described above, and the carrier sense timing 118-1 is the transmission telegram 110-1. The case where it coincides with the start timing is taken as an example.

  In this case, as shown in the message reception in FIG. 6D, since the message can be received by the carrier sense based on the carrier sense timing 118-1 for the time longer than the carrier sense essential time T5, the reception can be completed.

  FIG. 7 shows a case where the same carrier sense period Tcs = 2.7 sec as in FIG. 6 is set. However, as shown in FIG. 7C, the carrier sense timing 118- is set for the first transmission telegram 110-1. 1 shows a state in which the message cannot be received because the carrier sense timing 118-2 is appropriate for the second transmission message 110-2 and the message is received.

  In this case, the reception preparation operation is started at the carrier sense timing 118-1 for the first transmission telegram 110-1, but the reception operation is effectively performed because the reception for the carrier sense essential time T5 cannot be performed. Absent. However, at the next carrier sense timing 118-2, the message can be received for a time equal to or longer than the carrier sense essential time T5, so that the reception can be completed.

  The carrier sense period Tcs is determined such that a message can be effectively received at least once by N carrier senses for N transmission messages 110-1 to 110-N. As a method, it can be generalized.

  Generalizing equations (1) to (5) gives the following.

Formula (1) is directly Tcs> T1 (6)
Equation (2) is expressed as Tcs × (N−1) ≧ T4 (7)
It becomes.

Equation (3) is expressed as Tcs ≦ {T3 × N + T4 × (N−1)} / N (8)
It becomes.

Furthermore, conditional expression (4) is
(T3 × N) / {T3 × N + T4 × (N−1)} ≧ 1 / N (9)
It becomes.

And the expression (5) that summarizes the expressions (7) and (8) is
{T3 × N + T4 × (N−1)} / N ≧ Tcs ≧ T4 / (N−1) (10)
It becomes.

Further, the carrier sense period Tcs when N = 3 is given by substituting N = 3 into the general formulas (6) to (10).
Tcs> T1 (11)
Tcs × 2 ≧ T4 (12)
Tcs ≦ (T3 × 3 + T4 × 2) / 3 (13)
T3 × 3 / (T3 × 3 + T4 × 2) ≧ 1/3 (14)
(T3 × 3 + T4 × 2) / 3 ≧ Tcs ≧ T4 / 2 (15)
FIG. 4 is a block diagram showing the details of the radio reception repeater 12-1 and the P-type receiver 10 of FIG.

  4, the wireless reception repeater 12-1 includes a processor 42, a wireless communication unit 44 including a reception circuit, an antenna 46, a wired communication unit 48, an operation unit 50, a display unit 52, a memory 54, and a power supply unit 56. Composed.

  The processor 42 is provided with a reception processing unit 86 as a function realized by executing the program. The memory 54 is provided with a relay control table 87. As shown in FIG. 1, the wireless sensors 16-13 and 16-14 previously assigned as child nodes to the wireless reception repeater 12-1 and the radio wave relay. The node ID of the device 14-1 is registered.

  The reception processing unit 86 registers the node ID in the relay control table 87. When registering the node IDs of the wireless sensors 16-13 and 16-14 and the radio wave repeater 14-1, the registration address of the sensor or the radio wave repeater using, for example, a 7-segment display of the display unit 52 Next, a registration waiting state is set by a dip switch or the like of the operation unit 50, and in this state, an activation message transmitted from the wireless sensors 16-13, 16-14 or the radio relay 14-1 or A test message is received, a transmission source ID included in the message is acquired and registered in the relay control table 87.

  The reception processor 86 completes registration of the node IDs of the wireless sensors 16-13 and 16-14 and the radio repeater 14-1 assigned as child nodes, and is then transmitted from the radio repeater 14-1. When the registration request message including the node ID registered in the incoming relay control table 85 is received, the node IDs of the wireless sensors 16-11 and 16-12 acquired from the registration request message are stored in the relay control table 87. Register additional. In this case, since the address of the radio repeater 14-1 as the parent node is also sent at the same time, this is also registered.

  When the reception processing unit 86 determines a wireless sensor or radio wave repeater that does not receive the periodic notification message and becomes abnormal in periodic notification, the disconnection detection resistor connected to the end of the sensor line 18 is disconnected, By creating a disconnection state, the P-type receiver 10 is notified of the occurrence of a failure due to a periodic report abnormality.

  Further, as shown in FIG. 1, the power supply unit 56 is supplied with DC power from the receiver 10 through the power supply line 15.

  Next, the P-type receiver 10 of FIG. 4 will be described. In FIG. 4, a P-type receiver 10 includes a processor 58 functioning as a control unit, line receiving units 60-1 to 60-3, a power supply unit 62, a display unit 64, an acoustic alarm unit 66, an operation unit 68, and a transfer unit. 70 and a non-volatile memory 72. 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 60-1 to 60-3, respectively, and the wireless reception repeater 12-1 is connected to the sensor line 18-1. Is connected.

  The line receiving unit 60-1 detects the alarm current that flows through the contact operation by the wired communication unit 48 provided in the wireless reception repeater 12-1, and outputs a fire detection signal to the processor 58. The disconnection of the terminating resistor in the wired communication unit 48 of the wireless reception repeater 12-1 is detected as an interruption of the monitoring current when the actual sensor line is disconnected, and a failure detection signal is output to the processor 58.

  The processor 58 includes a CPU, a ROM, a RAM, an AD conversion port, and various input / output ports, and realizes the function of the fire monitoring unit 88 by executing a program by the CPU.

  The fire monitoring unit 88 determines that the fire detection signal of the corresponding sensor line is generated when the reception output of the fire alarm signal is obtained by detecting the alarm current by any of the line reception units 60-1 to 60-3, A representative fire display is displayed on the display unit 64, and a district display is performed for each line. An acoustic fire alarm is output from the acoustic alarm unit 66.

  In addition, when the line monitoring units 60-1 to 60-3 detect the disconnection of the sensor lines 18-1 to 18-3, the fire monitoring unit 88 displays a representative failure on the display unit 64 and generates a failure. The district is displayed for each line, and an acoustic failure alarm is output from the acoustic alarm unit 66.

  FIG. 8 is a time chart showing details of transmission switching processing by the transmission switching unit 78 provided in the wireless sensor 16-11 of FIG.

  FIG. 8A shows a case where a set of telegrams is transmitted based on the occurrence of event A, and a telegram having the format shown in FIG. 5, that is, a telegram with a transmission time T1 with a transmission pause of pause time T2. After repeating transmissions A1, A2 and A3 three times, a random pause time T6 unique to the sensor is arranged, and thereafter, 3 message transmissions A4, A5 and A6 of the transmission time T1 are inserted with the transmission pause of the pause time T2. Repeated times.

  In FIG. 8B, one set of message transmission is started based on the occurrence of the event A, and the message transmission and the transmission suspension that enable intermittent reception by the radio wave repeater 14-1 on the reception side are repeated twice. This is a case where an urgent event B occurs during the state change occurrence period.

  When an emergency event occurs during the transmission of a message based on the occurrence of the preceding event A in this way, in this embodiment, the transmission of the two message transmissions A1 and A2 necessary for the intermittent reception of the preceding event A is completed. Then, at the timing when the pause time T2 has elapsed, switching to one set of message transmissions B1 to B6 based on the occurrence of the emergency event B is performed.

  By switching to a message transmission based on an urgent event that occurred during a message transmission based on such a preceding event, even if it is an urgent event, the message transmission of the preceding event is not impaired, and the minimum delay is necessary. Can be sent to the receiver side.

  FIG. 9 is a time chart showing a problem when transmission switching is not performed according to the present embodiment. FIG. 9A shows one set of transmission operation in response to an event occurrence, and FIGS. Communication switching not according to the present embodiment is shown.

  FIG. 9B shows a case where one set of message transmissions B1 to B6 based on the occurrence of event B is performed after completion of one set of message transmissions A1 to A6 by the preceding event A. For example, T1 = T2 = Assuming that 2 sec and T6 = 4 sec, message transmission of event B is started after about 26 sec, and two message transmissions B1 and B2 are required for intermittent reception, resulting in a delay of about 32 seconds.

  On the other hand, in the present embodiment shown in FIG. 8B, message transmission is started about 8 seconds after the occurrence of the emergency event B, and it takes about 14 seconds to perform two message transmissions B1 and B2 necessary for intermittent reception. Thus, the delay time can be reduced to almost half. For example, when a wireless sensor is tested by a tester's switch operation, the test result can be sent to the receiver in a short time.

  FIG. 9C shows a case where when event B occurs, one set of message transmission based on the preceding event A is stopped and immediately switched to message transmission B1 to B6 based on event B. In this case, since the message based on the occurrence of the event A is performed only once for the message transmission A1, the timing of intermittent reception in the radio wave repeater 14-1, for example, the carrier as shown in FIG. At the sense timing, the first message transmission A1 cannot be received, and intermittent reception may not be possible, so communication reliability is lacking.

  The communication switching problem shown in FIGS. 9B and 9C is solved by the communication switching according to the present embodiment shown in FIG. 8B, and the subsequent message transmission based on the occurrence of the preceding event is not impaired. It is possible to transmit a message based on the occurrence of an event with a minimum necessary time delay.

  FIG. 10 is a flowchart showing sensor processing by the wireless sensor 16-11 of FIG. 3 and is realized by executing a program by the processor 20. In FIG. 10, the sensor process is initialized and self-diagnosed in step S1, and if normal, the process proceeds to step S2 to execute a registration process.

  In the registration process of step S2, when a registration mode is set by a dip switch or the like provided on the operation unit 28 of the wireless sensor 16-11, a test message for ID registration is transmitted. At this time, the corresponding radio relay 14 If the registration address is specified by the registration switch of the operation unit 36 and the registration waiting state is set, the transmission source ID included in the received test message is extracted and registered as a node ID in the relay control table 85. Automatic registration is performed.

  In step S3, it is determined whether or not an event has occurred. If it is determined in step S3 that an event has occurred, the process proceeds to step S4, where one set of message transmission shown in FIG. 5 is started using message contents (fire occurrence, fire recovery, failure, etc.) corresponding to the event contents as message data.

  During the transmission of the message, it is determined whether or not the transmission has ended in step S5, and during the communication, whether or not an emergency event has occurred is determined in step S6. If it is determined in step S6 that an urgent event has occurred during communication, the process proceeds to step S7, and the transmission based on the preceding event is stopped after the two message transmissions over the transmission time T1 are terminated. A set of messages is transmitted based on the occurrence of an emergency event at the timing when T2 has elapsed.

  Subsequently, in step S9, it is determined whether or not the periodic notification timer has expired. If it is determined that the periodic notification timer has expired, the periodic notification message is intermittently transmitted in step S10, and then the periodic notification timer is reset in step S11. Start.

  FIG. 11 is a flowchart showing the radio wave relay process by the radio wave repeater 14-1 in FIG. 3, which is a process realized by executing a program by the processor 32.

  In FIG. 11, in the radio wave relay process, after performing initialization and self-diagnosis upon power-on in step S21, if there is no abnormality, registration process of the relay control table 85 is executed in step S22.

  When the registration process in step S22 is completed, the monitoring state is entered, and the intermittent reception process based on the carrier sense period Tcs set in step S23 is performed. Subsequently, at step 24, it is determined whether or not the message has been received effectively. This validity determination is determined as valid and stored as message data when the two message data obtained by starting reception by carrier sense match.

  When it is determined in step 24 that the electronic message is validly received, the process proceeds to step S25, where the received message is analyzed, and the source ID obtained from the message in step S26 and the node ID of the table registration registered in the relay control table 85 are obtained. Are compared to each other, the process proceeds to step S27 as a valid received message, and the received message is relayed and transmitted.

  Subsequently, in step S28, it is determined whether or not the periodic notification timer has expired. If it is determined that the time has expired, a periodic notification message is transmitted in step S29, and then the periodic notification timer is reset and started in step S30. Return to.

  FIG. 12 is a flowchart showing a wireless reception relay process by the wireless reception repeater 12-1 of FIG. In FIG. 12, when the radio reception repeater 12-1 is turned on, initialization and self-diagnosis are executed in step S31. If there is no abnormality, registration processing of the relay control table 87 is executed in step S32. .

  When the registration process ends, the monitoring state is entered, and in step S33, it is determined whether or not there is an effective message reception in which the transmission source ID of the received message matches the node ID of the table registration. If it is determined in step S33 that a valid message has been received, the message is analyzed in step S34, and if a fire alarm is determined in step S35, a notification current is passed through the contact output to the sensor line 18 in step S36. A fire alarm signal is transmitted to the machine 10 to output a fire alarm.

  If it is determined in step S37 that the message is a periodic notification message, the process proceeds to step S38, and the periodic notification timer of the corresponding node specified by the transmission source ID is reset and started.

  Subsequently, in step S39, it is checked whether or not there is a periodic notification timer that has timed up. If there is a periodic notification timer that has expired, it is determined in step S40 that the periodic notification is abnormal, and the sensor line 18 is set in a pseudo disconnection state. Thus, a failure signal is sent to the P-type receiver 10 to output a failure alarm.

  In FIG. 8B, the message transmission is stopped at the end of the two message transmissions A1 and A2 based on the preceding event and switched to the message transmissions B1 to B6 based on the subsequent emergency event B. If an emergency event B occurs after the end of message transmissions A1 and A2, the event A message has already been intermittently received, and thereafter, transmission suspension after event message A3 to A6 message transmission It is also possible to switch to a non-urgent event message transmission at the time when is completed.

  Moreover, although this invention took the radio | wireless disaster prevention system as an example, it is not limited to this, It can apply to transmission of the transmission node in an appropriate radio system, and intermittent reception of the reception node.

  In the above embodiment, the case of two message transmissions and two carrier senses has been described as an example, but the same can be applied to the case of N message transmissions and N carrier senses.

  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 make it do.

  In addition, the flowcharts in the above-described embodiments have described a schematic example of processing, and the order of processing is not limited to this. Further, it is possible to provide a delay time between each process or between processes, insert another determination, or the like.

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.

10: P-type receivers 12-1 to 12-3: Radio reception repeaters 14-1 to 14-3: Radio wave repeaters 15: Power supply lines 16-11 to 16-34: Wireless sensors 18-1 to 18-1 18-3: Sensor lines 20, 32, 42, 58: Processors 22, 34, 44: Wireless communication units 24, 35, 46: Antenna 26: Sensor units 28, 36, 50, 68: Operation unit 30: Battery 38 , 54: Memory 40, 56, 62: Power supply unit 48: Wired communication unit 52, 64: Display unit 60-1 to 60-3: Line reception unit 66: Acoustic alarm unit 70: Transfer unit 72: Non-volatile memory 74: Sensor processing unit 76: transmission processing unit 78: transmission switching unit 80: carrier sense cycle setting unit 82: intermittent reception processing unit 84: relay processing unit 85, 87: relay control table 86: reception processing unit 88: fire monitoring unit 90: Message format 92: rank Modify signal 94: serial number 96: the sender ID
98: Message content 100: Error check code 110-1 to 110-6: Transmission message 112-1 to 112-18: Message data 114-1 to 114-3: Receivable start time 116-1 to 116-2: Reception Unstartable period 118-1 to 118-4: carrier sense timing

Claims (7)

The radio disaster prevention node includes a sensor node, a radio relay node, a radio disaster prevention node, and a receiver, and receives a telegram signal transmitted from the sensor node or a telegram signal transmitted from the sensor node via the radio relay node. In the wireless disaster prevention system that transmits the processing result to the receiver connected by a signal line,
The sensor node is
A transmission processing unit that repeats at least two times a message transmission that continuously transmits the same message signal over a predetermined message transmission time and a message pause that pauses the message transmission for a predetermined time when an event occurs;
When an emergency event without urgent processing occurs during less than two repetitions of message transmission and message suspension based on the preceding event occurrence by the transmission processing unit, message transmission and message suspension based on the preceding event are performed. A transmission switching unit that switches between message transmission and message suspension based on the urgent event after being canceled twice, and
With
The radio relay system according to claim 1, wherein the radio relay node includes an intermittent receiving unit that receives intermittently so that a reception timing is included in at least one of two consecutive message transmissions with the message pause.
The wireless disaster prevention system according to claim 1, wherein the emergency event generated at the sensor node includes an operation event such as a switch operation, a failure event, and a periodic notification event.
2. The wireless disaster prevention system according to claim 1, wherein the transmission processing unit of the sensor node repeats a message transmission and a message suspension three times when an event occurs, and then a predetermined random suspension time set randomly for each node. The wireless disaster prevention system is characterized in that a message transmission and a message suspension are repeated three times after the random suspension time.
In the wireless disaster prevention system according to claim 1,
The intermittent receiver is
Carrier sense for setting a carrier sense period when performing carrier sense N times so that a predetermined carrier sense essential time overlaps at least one of two times of message transmission times that are a plurality of times that are continuous with the message pause time in between A cycle setting unit;
An intermittent receiving unit that detects the presence or absence of a carrier of the telegram signal for each carrier sense period and processes a telegram received when a carrier detection state continues for the carrier sense essential time or more;
With
The carrier sense cycle setting unit
The message transmission time is T1, the message suspension time is T2, the reception start possible time obtained by subtracting the minimum carrier sense required time T5 required for the reception operation from the message transmission time T1 is T3, and the carrier sense is required for the message suspension time T2. When the reception start impossible time including the time T5 is T4,
The reception start possible time is T3 and the reception start impossible time T4 (T3 × 2) / (T3 × 2 + T4 ×) ≧ 1/2
If the above condition is satisfied, the carrier sense period Tcs is set to (T3 × 2 + T4) / 2 ≧ Tcs ≧ T4
A wireless disaster prevention system characterized in that it is set to a value in the range.
When an event occurs, a sensor node that transmits a telegram signal to a radio wave relay node that receives intermittently so that a reception timing is included in at least one of two telegram transmissions that are a predetermined time with a message pause for a predetermined time. And
A transmission processing unit that repeats at least two times a message transmission that continuously transmits the same message signal over a predetermined message transmission time and a message pause that pauses the message transmission for a predetermined time when an event occurs;
When an emergency event without urgent processing occurs during less than two repetitions of message transmission and message suspension based on the preceding event occurrence by the transmission processing unit, message transmission and message suspension based on the preceding event are performed. A transmission switching unit that switches between message transmission and message suspension based on the urgent event after being canceled twice, and
A sensor node comprising:
6. The sensor node according to claim 5, wherein the emergency event includes an operation event such as a switch operation, a failure event, and a periodic notification event.
  The sensor node according to claim 5, wherein the transmission processing unit arranges a predetermined random pause time set at random for each node after repeating the message transmission and the message pause three times when an event occurs. A sensor node characterized by repeating message transmission and message suspension three times after the random pause time.

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