JP6551616B2 - Wireless sensor system, wireless sensor terminal and data collection method - Google Patents

Description

  The present invention relates to a wireless sensor terminal that is attached to a moving body and wirelessly transmits data including a sense value detected by a sensor, a wireless sensor system including the wireless sensor terminal, and a data collection method using the wireless sensor system. .

  In a wireless sensor system that wirelessly collects data (sense value) obtained by a sensor attached to a mobile, depending on the position of the mobile, the condition of radio wave propagation by the shield or peripheral reflector worsens and communication data Loss may occur. Therefore, conventionally, various technologies have been proposed as a technique for dealing with a lack of communication data in a wireless sensor system (see, for example, Patent Document 1).

  In Patent Document 1, the frequency of data transmission is set according to the degree of occurrence of loss of communication data, so that the frequency of data received by the receiver is equalized, and the number of data received from the sensor fluctuates. By doing this, it is possible to prevent the weighting and updating frequency from becoming unstable.

JP 2012-160965 A

  However, since the technique of Patent Document 1 is premised on connection-type communication, overhead associated with establishing a connection occurs, and the operation time (particularly, reception time) of the wireless sensor terminal increases with reception confirmation. Or the operation time of the wireless sensor terminal becomes longer due to retransmission control. As a result, power consumption is increased, and when the wireless sensor terminal attached to the moving body is to be driven by a battery, there is a problem that the operating life of the wireless sensor terminal becomes extremely short.

  Here, in order to solve the problem associated with such connection-oriented communication, it is conceivable to employ broadcast-type (connectionless) communication that does not require a reception response. However, in the case of broadcast communication, it is necessary to repeatedly transmit the same data in order to cope with the loss of communication data. At this time, since the wireless sensor terminal that transmits data cannot receive feedback from the receiver, an appropriate number of retransmissions cannot be determined, and there is no choice but to leave room for the number of retransmissions. As a result, the power consumption of the wireless sensor terminal that transmits data eventually increases, or the receiving side that receives data makes the processing complicated by receiving the same data repeatedly, or the situation of radio wave propagation Therefore, there arises a problem that the weighting of data is erroneous due to the variation in the number of receptions.

  Therefore, the present invention has been made to solve such problems, and can reliably and easily perform data reception processing while suppressing increase in power consumption of a wireless sensor terminal that transmits data. An object is to provide a wireless sensor system, a wireless sensor terminal, and a data collection method.

  In order to achieve the above object, a wireless sensor system according to an aspect of the present invention is wirelessly attached to a mobile body, has a sensor, and wirelessly transmits data including a sense value detected by the sensor as a packet A sensor terminal, a receiver that wirelessly receives the packet transmitted from the wireless sensor terminal, and a host that receives the packet from the receiver, the wireless sensor terminal detects a new sense value by the sensor Each time it is detected, data including the detected sense value and a unique data ID corresponding to the detection is broadcast and transmitted as the packet.

  As a result, since the packet including the sense value is transmitted by the broadcast type with less overhead, it is possible to suppress the increase in the power consumption of the wireless sensor terminal as compared with the connection type communication. In addition, since the packet includes not only the sense value but also a unique data ID corresponding to the detection of the sense value, the host receiving the packet determines the data ID included in the packet, It is possible to know which detection (for example, the number of times of detection) by the sensor is the data included in the sense value included in, or that there is a missed reception. Therefore, it is suppressed that the power consumption of a radio | wireless sensor terminal becomes large by transmitting repeatedly the packet containing the same sense value uselessly. Then, in a host that receives data, processing may be complicated by redundantly receiving the same data, or weighting of data may be erroneous due to variations in the number of receptions depending on the state of radio wave propagation. Is suppressed, the data reception process is surely and easily performed, and is simplified.

  In addition, by evaluating the omission of reception, it becomes possible to evaluate the installation setting and operation status of the wireless sensor system depending on the installation position and the number of the receivers, and the optimization of the installation position and the number of the receivers It will be possible.

  Here, the wireless sensor terminal repeats the transmission of the packet a predetermined number of times at a predetermined time interval each time a new sense value is detected by the sensor, and the host receives the packet from the receiver. Among the packets, the number of packets including the same data ID is counted, a reception rate that is a ratio of the counted number to the predetermined number of times is calculated, and the plurality of packets including the same data ID are calculated. Keep only one packet.

  As a result, since transmission of a packet including the same sense value and data ID is repeated, even in the case where the radio wave condition is deteriorated, dropping of reception is suppressed. Furthermore, since the reception rate is calculated in real time during operation, the installation position and the number of receivers can be easily optimized. In addition, since the host holds only one of a plurality of packets including the same data ID, the storage capacity in the host due to the same packet being transmitted a plurality of times is avoided.

  Further, when repeating the transmission of the packet, the wireless sensor terminal transmits the packet after including a transmission ID corresponding to the number of transmissions among the predetermined number of times in each of the packets in the repetition. Do.

  In this way, the host can know that there was a missed reception not only for each data ID but also for each transmission ID in the same data ID by determining the transmission ID included in the received packet. The time-series change of the reception state is detected with higher accuracy.

  Further, the wireless sensor terminal transmits the packet after including the sense value detected in the past by the sensor in the packet each time a new sense value is detected by the sensor.

  Thus, a host that has received a packet including not only a new sense value but also a past sense value can check the received sense value by using the past sense value included in the packet. It is possible to confirm and complement sense values that could not be received, and the data processing in the host becomes reliable and easy.

  Further, the wireless sensor terminal further includes the data ID corresponding to the sense value detected in the past in the packet every time a new sense value is detected by the sensor. It may be sent.

  As a result, since the packet includes the data ID corresponding to the past sense value, the host that has received such a packet can use the past sense value included in the packet and its data ID as a pair. The data ID of the sense value that has already been received can be verified by collation or the sense value and data ID that could not be received can be complemented, making data processing at the host more reliable and easy. .

  Moreover, in order to achieve the said objective, the wireless sensor terminal which concerns on one form of this invention is a wireless sensor terminal in the said wireless sensor system.

  As a result, since the packet including the sense value is transmitted by the broadcast type with less overhead, it is possible to suppress the increase in the power consumption of the wireless sensor terminal as compared with the connection type communication. In addition, since the packet includes not only the sense value but also a unique data ID corresponding to the detection of the sense value, the host receiving the packet determines the data ID included in the packet, It is possible to know which detection (for example, the number of times of detection) by the sensor is the data included in the sense value included in, or that there is a missed reception. Therefore, in the host that receives data, the process of receiving data becomes reliable and easy and is simplified.

  Further, to achieve the above object, a data collection method according to an aspect of the present invention is a data collection method by a wireless sensor system including a wireless sensor terminal attached to a mobile, a receiver, and a host. The wireless sensor terminal wirelessly transmits data including a sense value detected by a sensor included in the wireless sensor terminal as a packet; and the receiver transmits the packet transmitted from the wireless sensor terminal. Wirelessly receiving, and managing the host receiving and managing the packet from the receiver, and in the transmitting, the wireless sensor terminal is newly detected with a sense value by the sensor Each time, the detected sense value, a unique data ID corresponding to the detected value, and a previously detected sensor The wireless transmission of the data including the value and the data as the packet is repeated a predetermined number of times at a predetermined time interval, and in the repetition, each of the packets corresponds to the number of transmissions among the predetermined number of times In the management step, the host counts the number of packets including the same data ID among the packets received from the receiver, and the number of the counted number for the predetermined number of times is included in the management step. The reception rate which is a ratio is calculated, and only the data in one packet is held for a plurality of the packets including the same data ID.

  As a result, since the packet including the sense value is transmitted by the broadcast type with less overhead, it is possible to suppress the increase in the power consumption of the wireless sensor terminal as compared with the connection type communication. In addition, since the packet includes not only the sense value but also a unique data ID corresponding to the detection of the sense value, the host that has received the packet determines the data ID included in the packet to determine the packet. It is possible to know which detection (for example, the number of times of detection) by the sensor is the data included in the sense value included in, or that there is a missed reception. Therefore, in the host that receives data, the process of receiving data becomes reliable and easy and is simplified.

  The present invention provides a wireless sensor system, a wireless sensor terminal, and a data collection method that can reliably and easily perform data reception processing while suppressing an increase in power consumption of the wireless sensor terminal that transmits data.

FIG. 1 is a block diagram illustrating a configuration of a wireless sensor system according to the first embodiment. FIG. 2 is a block diagram showing the configuration of the wireless sensor terminal in FIG. FIG. 3 is a block diagram showing the configuration of the receiver in FIG. FIG. 4 is a flowchart showing the operation of the wireless sensor system according to the first embodiment. FIG. 5 is a diagram showing an example of a data structure of a packet generated by the wireless sensor terminal. FIG. 6 is a timing chart showing the operation of the wireless sensor terminal. FIG. 7 is a diagram illustrating another example of a data structure of a packet transmitted by the wireless sensor terminal. FIG. 8 is a block diagram illustrating a configuration of the wireless sensor system according to the second embodiment. FIG. 9 is a flowchart showing the operation of the wireless sensor system according to the second embodiment. FIG. 10 is a diagram showing an example of a data structure of a packet generated by the wireless sensor terminal. FIG. 11 is a timing chart showing the operation of the wireless sensor terminal. FIG. 12 is a block diagram illustrating a configuration of the wireless sensor system according to the third embodiment. FIG. 13 is a block diagram showing the configuration of the first gateway and the second gateway in FIG. FIG. 14 is a flowchart showing the operation of the wireless sensor system according to the third embodiment. FIG. 15 is a diagram illustrating an example of a data structure of a packet generated by the wireless sensor terminal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. Numerical values, materials, communication systems, data structures, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. . In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are described as optional constituent elements. Moreover, each figure is not necessarily illustrated exactly. In the drawings, substantially the same components are denoted by the same reference numerals, and redundant description will be omitted or simplified.

Embodiment 1
First, the wireless sensor system according to Embodiment 1 will be described.

  FIG. 1 is a block diagram showing the configuration of the wireless sensor system 10 according to the first embodiment.

  The wireless sensor system 10 is a system for collecting a sense value detected by a sensor attached to a mobile, and a plurality of wireless sensor terminals 20a to 20c attached to each mobile (not shown), a receiver 30, And a personal computer (personal computer) 40.

  Each of the wireless sensor terminals 20a to 20c is a portable terminal that is attached to each moving body, has a sensor, and wirelessly transmits data including a sense value detected by the sensor as a packet. It is attached to the person who sends it and transmits biological information such as the temperature of the person. Each time a sense value is newly detected by the sensor, the wireless sensor terminals 20a to 20c wirelessly transmit the data including the detected sense value and a unique data ID corresponding to the detection as a packet (connectionless) Type transmission).

  The broadcast transmission here is a one-way transmission that does not require confirmation of reception of ACK or the like. Further, in the present embodiment, the data ID is a sequential numerical value, and specifically, is an integer which is incremented by 1 each time a sensor value is newly detected by the sensor.

  The receiver 30 is a communication interface that functions as a receiving base station that wirelessly receives packets broadcasted from the wireless sensor terminals 20 a to 20 c and transfers the packets to the personal computer 40. The receiver 30 is, for example, connected to a network with the personal computer 40, and operates by receiving power supply from the personal computer 40.

  The personal computer 40 is an example of a host that receives packets from the receiver 30, and includes a CPU, a ROM, a RAM, a hard disk for storing programs and data, a personal computer main body including an input / output port connected to the receiver 30, a display, and a keyboard. And an input device such as a mouse. The personal computer 40 extracts the data ID and the sense value from the packet received from the receiver 30, and stores the extracted data ID and the sense value in association with each other.

  FIG. 2 is a block diagram showing the configuration of wireless sensor terminals 20a to 20c in FIG. Each of the wireless sensor terminals 20 a to 20 c has the same configuration, and includes an antenna 21, a wireless communication / control circuit 22, a measurement circuit 23, and a battery 24.

  The antenna 21 is an antenna suitable for a frequency band used by the wireless sensor terminals 20a to 20c to transmit packets wirelessly.

  The wireless communication / control circuit 22 is a circuit that performs wireless communication and control in the wireless sensor terminals 20a to 20c, and includes a transmission unit 22a, a RAM 22b, a CPU 22c, and a ROM 22d. The transmission unit 22a is a transmission circuit that modulates and amplifies a packet output from the CPU 22c into a high frequency signal of a predetermined frequency band and supplies the high frequency signal to the antenna 21. The transmission unit 22a transmits, for example, according to the Bluetooth (registered trademark) communication system. The RAM 22 b is a memory for temporarily storing data. The ROM 22 d is a read only memory that holds programs and data. The CPU 22c executes control of the wireless sensor terminals 20a to 20c such as outputting the data obtained by the measurement circuit 23 as a packet to the transmission unit 22a by executing the program held in the ROM 22d while using the RAM 22b.

  The measurement circuit 23 includes a sensor 23a and an ADC 23b, and generates a sense value by converting an analog signal detected by the sensor 23a into a digital signal by the ADC 23b, and outputs the sense value to the CPU 22c. The sensor 23a is, for example, a thermistor for measuring a temperature.

  The battery 24 is a power supply for supplying power to the wireless communication / control circuit 22 and the measuring circuit 23. For example, not only the battery but also a constant voltage circuit for obtaining power from the battery and converting it to a predetermined voltage may be included. Good.

  FIG. 3 is a block diagram showing the configuration of the receiver 30 in FIG. The receiver 30 includes an antenna 31 and a communication circuit 32.

  The antenna 31 is an antenna suitable for a frequency band used to receive packets wirelessly transmitted from the wireless sensor terminals 20a to 20c.

  The communication circuit 32 is a circuit that wirelessly receives a packet received via the antenna 31 and transfers the packet to the personal computer 40, and includes a receiver 32a and a wired I / O 32b. The receiving unit 32a is a circuit that takes out a data body (payload) by filtering and demodulating a high frequency signal received through the antenna 31 and restoring it into a packet, and then removing a header depending on the communication system. The receiving unit 32a receives, for example, according to the Bluetooth (registered trademark) communication scheme. The wired I / O 32b transfers the data body extracted by the receiving unit 32a (hereinafter, the data body from which the header depending on the communication method has been removed is also referred to as a “packet”) to the personal computer 40 connected via wire. Communication interface.

  Next, the operation (that is, the data collection method) of the wireless sensor system 10 according to the present embodiment configured as described above will be described.

  FIG. 4 is a flowchart showing the operation of the wireless sensor system 10 according to the first embodiment. Here, the operations of the wireless sensor terminals 20a to 20c, the receiver 30 and the personal computer 40 and the exchange of data with each other are shown.

  In the wireless sensor terminals 20a to 20c, the wireless communication / control circuit 22 (more specifically, the CPU 22c) is activated when the battery 24 is attached and performs initialization (S10). Here, the data ID is set to 1 as initialization. The initial value of the data ID is not limited to 1 and may be any other value.

  Subsequently, the wireless communication / control circuit 22 acquires, from the measurement circuit 23, the sense value generated by converting the analog signal detected by the sensor 23a into a digital signal by the ADC 23b (S11).

  Then, the wireless communication / control circuit 22 adds the data ID generated immediately before (the data ID initialized in step S10 for the first time and the data ID incremented in step S15 for the second time or later) to the acquired sense value ( S12).

  Subsequently, the wireless communication / control circuit 22 generates a packet by adding a header according to the communication method (for example, Bluetooth (registered trademark)) to the sense value to which the data ID is added (S13). FIG. 5 is a diagram illustrating an example of a data structure of a packet generated by the wireless sensor terminals 20a to 20c. A data structure is shown in which a data ID is added to the sense value and a header is further added. The identification information (transmission source address or the like) of the wireless sensor terminals 20a to 20c may be included in the header, or in addition to or instead of the data main body (payload).

  Then, the wireless communication / control circuit 22 broadcasts the generated packet via the antenna 21 (transmission step S14).

  Subsequently, the wireless communication / control circuit 22 increments the data ID by 1 (S15), and enters the sleep state for a predetermined time (S16). In the sleep state, the wireless communication / control circuit 22 performs only the minimum operation such as monitoring the lapse of a predetermined time, and the power consumption of the wireless sensor terminals 20a to 20c becomes very small.

  When the predetermined time elapses, the wireless communication / control circuit 22 repeats the process from the acquisition of the sense value (S11) to the sleep state (S16) again.

  FIG. 6 is a timing chart showing the operation of the wireless sensor terminals 20a to 20c. (A) of FIG. 6 shows the entire operation (the timing at which the wireless sensor terminals 20a to 20c operate in the normal state other than the sleep state). (B) of FIG. 6 shows the operation of the measurement circuit 23 in the wireless sensor terminals 20a to 20c. (C) of FIG. 6 shows an operation of wireless transmission of the wireless sensor terminals 20a to 20c. FIG. 6D shows details of wireless transmission of the wireless sensor terminals 20a to 20c (expanded timing of FIG. 6C).

  As shown in (a) of FIG. 6, the wireless sensor terminals 20a to 20c operate in a sleep state after being operated for a predetermined time (the “operation time” in the drawing) in a predetermined cycle (“starting in the Repeat at intervals "). The predetermined time for entering the sleep state corresponds to a time obtained by subtracting “operation time” from “start-up time”. For example, the activation time is 1 hour and the operation time is 2 seconds.

  Further, as shown in FIGS. 6B and 6C, each time a new measurement is performed by the measurement circuit 23, the data ID is incremented by one. Here, the data ID is set so as to match the number of times of measurement (“measurement No.” in the figure).

  Further, as shown in (d) of FIG. 6, one operation time is a time during which the wireless sensor terminals 20a to 20c return from the sleep state to the normal state to obtain a sense value (a time of “activation process” in the figure). And a time for transmitting the obtained sense value as a packet ("transmission interval" in the figure, "transmission time").

  Referring to FIG. 4 again, in the receiver 30, on the other hand, when the communication circuit 32 wirelessly receives the packet transmitted from the wireless sensor terminals 20a to 20c, the communication circuit 32 removes the header depending on the communication method. , And transferred to the personal computer 40 (reception step S20).

  The personal computer 40 receives and manages the packet transferred from the receiver 30 (management steps S30 to S33).

  Specifically, when the personal computer 40 acquires a packet transferred from the receiver 30 (S30), it extracts the data ID and the sense value from the acquired packet, and associates the extracted data ID with the sense value. Data processing for storage is performed (S31).

  Subsequently, the personal computer 40 determines whether or not there is a missing data ID (that is, reception omission) by checking the continuity between the data ID just received and the data ID just received, or It is determined whether or not an abnormality has been detected by determining whether or not the sense value just received is within the reference range (S32). As a result, if it is determined that an abnormality has been detected (YES in S32), the personal computer 40 issues an alert by displaying on the display, outputting an alarm, sending an e-mail to a predetermined destination, etc. (S33). . The processes (S30 to S33) in the personal computer 40 described above are wireless based on the identification information of the wireless sensor terminal included in the header or data body (payload) of the packet transmitted from the wireless sensor terminals 20a to 20c. It is performed for each of the sensor terminals 20a to 20c.

  The data ID used in the wireless sensor system 10 according to the present embodiment is a value that is updated each time a new measurement is performed, that is, a sense value is newly detected (an ID assigned in the application layer). Depending on the communication system, it is different from the packet ID (for example, a sequence number in TCP (Transmission Control Protocol)) that may be given as a standard in a communication layer lower than the application layer. The packet ID normally assigned in the communication layer lower than the application layer is set to a different value if it is separated into different packets even if the data constitutes the same sense value, so one measurement It cannot be used for management in units of (that is, one sense value).

  As described above, the wireless sensor system 10 according to the present embodiment is attached to a moving body, has a sensor 23a, and wirelessly transmits data including a sense value detected by the sensor 23a as a packet. 20a to 20c, a receiver 30 that wirelessly receives packets transmitted from the wireless sensor terminals 20a to 20c, and a personal computer 40 that is a host that receives packets from the receiver 30. Each time a sense value is newly detected by the sensor 23a, the wireless sensor terminals 20a to 20c broadcast and transmit data including the detected sense value and a unique data ID corresponding to the detection as a packet. The personal computer 40 extracts the data ID and the sense value from the packet received from the receiver 30, and stores the extracted data ID and the sense value in association with each other.

  The data collection method by the wireless sensor system 10 according to the present embodiment is a data collection method by the wireless sensor system 10 including the wireless sensor terminals 20a to 20c, the receiver 30, and the personal computer 40 as a host. The wireless sensor terminals 20a to 20c wirelessly transmit data including a sense value detected by the sensor 23a attached to the moving body as a packet, and the receiver 30 receives the wireless sensor terminals 20a to 20c from the wireless sensor terminals 20a to 20c. It includes a receiving step S20 for wirelessly receiving the transmitted packet, and management steps S30 to S33 in which the personal computer 40 receives the packet from the receiver 30 and manages the packet. In the transmitting step S14, the wireless sensor terminals 20a to 20c wirelessly transmit, as a packet, data including the detected sense value and a unique data ID corresponding to the detection each time the sensor 23a newly detects the sense value. In the management steps S30 to S33, the personal computer 40 extracts the data ID and the sense value from the packet received from the receiver 30, and associates and holds the extracted data ID and the sense value.

  As a result, since the packet including the sense value is transmitted by the broadcast type with less overhead, the power consumption of the wireless sensor terminals 20a to 20c is suppressed from being increased as compared with the connection type communication. In addition, since the packet includes not only the sense value but also a unique data ID corresponding to the detection of the sense value, the personal computer 40 that has received the packet determines the data ID contained in the packet, so that the packet It is possible to know which detection (for example, the number of times of detection) by the sensor 23a is the data included in the sensor value, or that there is a missed reception. Therefore, it is suppressed that the power consumption of the wireless sensor terminals 20a to 20c is increased by repeatedly transmitting packets including the same sense value in vain. Then, in the personal computer 40 that receives data, processing may be complicated by redundantly receiving the same data, or weighting of data may be mistaken by variation in the number of receptions depending on the state of radio wave propagation. And the process of receiving data is made reliable and easy and is simplified.

  In addition, by evaluating the omission of reception, it becomes possible to evaluate the installation setting and the operation state of the wireless sensor system 10 depending on the installation position and the installation number of the receivers 30, and the installation position and the installation number of the receivers 30. Optimization is possible.

  The RSSI (Received Signal Strength Indicator), BER (Bit Error Rate), and SN ratio (signal-noise ratio) acquired by the receiver 30 for managing the reception state of the personal computer 40 A time-series change such as a signal-to-noise ratio) may be stored together.

  Moreover, in the wireless sensor system 10 according to the present embodiment, the packets transmitted by the wireless sensor terminals 20a to 20c include the data ID and the latest sense value, but may include the past sense values. Good.

  FIG. 7 is a diagram illustrating another example of a data structure of a packet transmitted by the wireless sensor terminals 20a to 20c. In (a) of FIG. 7, in the packet, in addition to the data ID and the latest sense value (“latest sense value”), the past sense value (here, “previous sense value” obtained in the previous measurement) ) Is stored. That is, in this example, each time the sense value is newly detected by the sensor 23a, the wireless sensor terminals 20a to 20c further detect the sense value previously detected by the sensor 23a (here, the previous sense value). Send the packet after including it in the packet. Thus, the personal computer 40 that receives a packet including not only a new sense value but also a past sense value collates the received sense value by using the past sense value included in the packet. Therefore, the sense value which can not be received can be complemented, and data processing in the personal computer 40 becomes reliable and easy.

  Further, in FIG. 7B, in the packet, in addition to the data ID and the latest sense value (“latest sense value”), the past sense value (here, “previous sense value”) and the past A data ID corresponding to the sense value (here, “previous data ID”) is stored. That is, in this example, the wireless sensor terminals 20a to 20c, in addition to the sense value previously detected by the sensor 23a (here, the previous sense value) each time a sense value is newly detected by the sensor 23a, Furthermore, the packet is transmitted after the data ID (here, the previous data ID) corresponding to the sense value detected in the past is included in the packet. As a result, since the packet includes the data ID corresponding to the past sense value, the personal computer 40 that has received such a packet uses the past sense value included in the packet and its data ID in pairs. Therefore, the data ID of the sense value already received can also be collated and confirmed, or the sense value and data ID which can not be received can be complemented, and the data processing in the personal computer 40 is more reliable and easy become.

Second Embodiment
Next, a wireless sensor system according to Embodiment 2 will be described.

  FIG. 8 is a block diagram showing the configuration of the wireless sensor system 10a according to the second embodiment.

  The wireless sensor system 10a is a system for collecting a sense value detected by a sensor attached to a mobile, and a plurality of wireless sensor terminals 20d to 20f attached to each mobile (not shown), a plurality of receivers (The 1st receiver 30a and the 2nd receiver 30b), and personal computer 40a are provided.

  Like the first embodiment, the wireless sensor terminals 20d to 20f have the basic configuration shown in FIG. 2 and have at least the same functions as the wireless sensor terminals 20d to 20f of the first embodiment, but additionally It has a function of repeatedly transmitting packets. More specifically, the wireless sensor terminals 20d to 20f transmit packets including the same data ID and sense value a predetermined number of times (M times) at predetermined time intervals each time the sensor 23a newly detects a sense value. repeat. At this time, when repeating transmission of packets, each of the wireless sensor terminals 20d to 20f includes a transmission ID corresponding to the number of transmissions of the predetermined number of times (M times) in each of the packets in the repetition, Send a packet In the present embodiment, the data ID is a value indicating the number of transmission repetitions.

  Each of the first receiver 30a and the second receiver 30b has the basic configuration shown in FIG. 3 as in the first embodiment, and has the same function as the receiver 30 of the first embodiment. That is, each of the first receiver 30a and the second receiver 30b functions as a receiving base station that wirelessly receives packets transmitted from the wireless sensor terminals 20d to 20f and transfers them to the personal computer 40a. However, the first receiver 30a and the second receiver 30b are different from each other in advance so as not to miss packets transmitted wirelessly from the wireless sensor terminals 20d to 20f attached to the moving body and moving. Installed in

  In addition to the basic configuration and functions similar to those of the first embodiment, the personal computer 40a performs processing involved in repeatedly receiving the same packet. That is, in the present embodiment, the personal computer 40a counts the number of packets that include the same data ID (and have different transmission IDs) among the packets received from the first receiver 30a and the second receiver 30b. The reception rate, which is the ratio of the counted number to the predetermined number (M times), is calculated. The personal computer 40a stores only the data in one packet for a plurality of packets including the same data ID. The personal computer 40a shares the predetermined number of times (M times) with the wireless sensor terminals 20d to 20f.

  Although the personal computer 40a may repeatedly receive packets including the same data ID and the same transmission ID from the first receiver 30a and the second receiver 30b, in this case, the receiver And two packets may be stored, or only one may be stored.

  Next, an operation (that is, a data collection method) of the wireless sensor system 10a according to the present embodiment configured as described above will be described.

  FIG. 9 is a flowchart showing the operation of the wireless sensor system 10a according to the second embodiment. Here, the operations of the wireless sensor terminals 20d to 20f, the receivers (the first receiver 30a and the second receiver 30b), and the personal computer 40a, and the exchange of data between each other are shown.

  In the wireless sensor terminals 20d to 20f, the wireless communication / control circuit 22 (more specifically, the CPU 22c) is activated when the battery 24 is attached and performs initialization (S40). Here, as initialization, the data ID is set to 1 and the transmission ID is set to 1. Note that the initial values of the data ID and the transmission ID are not limited to 1, and may be other arbitrary values.

  Subsequently, the wireless communication / control circuit 22 acquires, from the measurement circuit 23, the sense value generated by converting the analog signal detected by the sensor 23a into a digital signal by the ADC 23b (S41).

  Then, the wireless communication / control circuit 22 adds, to the acquired sense value, the data ID generated immediately before (data ID initialized in step S40 for the first time, data ID incremented in step S48 for the second time) S42).

  Subsequently, the radio communication / control circuit 22 determines that the transmission ID generated immediately before (the transmission ID initialized in step S40 for the first time and the transmission ID incremented in step S47 for the first time) is a predetermined value M (the predetermined number of times). It is determined whether the value is less than or equal to the value indicating (S43). Here, the predetermined value M is a value preset as the number of times of repeated transmission of a packet including the same data ID, and is, for example, 720.

  As a result, if the transmission ID is less than or equal to the predetermined value M (YES in step S43), the wireless communication / control circuit 22 adds the transmission ID to the sense value to which the data ID is added (S44), and A packet is generated by adding a header according to a communication method (for example, Bluetooth (registered trademark)) (S45). FIG. 10 is a diagram illustrating an example of a data structure of a packet generated by the wireless sensor terminals 20d to 20f. A data structure is shown in which a data ID and a transmission ID are added to the sense value, and a header is further added.

  Then, the wireless communication / control circuit 22 broadcasts the generated packet via the antenna 21 (transmission step S46).

  Subsequently, the wireless communication / control circuit 22 increments the transmission ID by 1 (S47), and repeats the determination in step S43 and the subsequent processing again.

  If it is determined in step S43 that the transmission ID is not less than or equal to the predetermined value M (NO in step S43), the wireless communication / control circuit 22 increments the data ID by 1 (S48) and initializes the transmission ID ( Here, after being set to 1) (S49), a sleep state is set for a predetermined time (S50).

  When the predetermined time has elapsed, the wireless communication / control circuit 22 repeats the processing from the acquisition of the sense value (S41) to the sleep state (S50) again.

  FIG. 11 is a timing chart showing operations of the wireless sensor terminals 20d to 20f. (A) of FIG. 11 shows the entire operation (the timing at which the wireless sensor terminals 20d to 20f operate in the normal state other than the sleep state). (B) of FIG. 11 shows the operation of the measurement circuit 23 in the wireless sensor terminals 20d to 20f. (C) of FIG. 11 shows the operation of wireless transmission of the wireless sensor terminals 20d to 20f. FIG. 11D shows the details of wireless transmission of the wireless sensor terminals 20d to 20f (expanded timing of FIG. 11C).

  As shown in FIG. 11 (a), in the present embodiment, the wireless sensor terminals 20d to 20f perform an operation in which the wireless sensor terminals 20d to 20f enter a sleep state after operating for a certain period of time (“operation time” in the figure). Repeat at ("Startup interval" in the figure).

  In this embodiment, as shown in (b) to (d) of FIG. 11, in order to repeatedly transmit a packet including the same data ID M times, it is grouped into m (<M) transmissions. There is. That is, the wireless sensor terminals 20d to 20f repeat the process of transmitting the packet including the same data ID m times and entering the sleep state M / m times to repeat the packet including the same data ID M times in total Send. Such a total of M repeated transmissions are repeated at the illustrated measurement intervals. Specifically, for example, the activation interval is 5 minutes, the operation time is 1 minute, the measurement interval is 1 hour, and the transmission interval is 1 second. Therefore, m is 60 (= operation time 1 minute / transmission interval 1 second), and M is 720 (= 60 × measurement interval 1 hour / startup interval 5 minutes).

  In this manner, M repeated transmissions are divided into a plurality of groups and temporally dispersed, thereby increasing the possibility that normal reception can be performed even if the wireless sensor terminals 20d to 20f move, and multiple sleeps Power consumption is suppressed depending on the state.

  On the other hand, in the first receiver 30a and the second receiver 30b of FIG. 9, when the communication circuit 32 wirelessly receives a packet broadcasted from the wireless sensor terminals 20d to 20f, the header depending on the communication system is removed. Then, the data is transferred to the personal computer 40a (reception steps S20a and S20b).

  Similarly to the first embodiment, the personal computer 40a receives and manages the packets transferred from the first receiver 30a and the second receiver 30b (management steps S30 to S33). That is, when the personal computer 40a acquires the packets transferred from the first receiver 30a and the second receiver 30b as in the first embodiment (S30), the personal computer 40a performs data processing (in the same manner as the first embodiment). S31), determination of abnormality detection (S32), and alert notification (S33) are performed.

  However, in this embodiment, in addition to the processing in the first embodiment, the personal computer 40a performs the same data processing (S31) among the packets received from the first receiver 30a and the second receiver 30b. The number of packets including data IDs (and different transmission IDs) is counted, a reception rate that is a ratio of the counted number to the predetermined number of times (M times) is calculated, and a plurality of packets including the same data ID is included. Stores only the data in one packet. Furthermore, when it is determined that the calculated reception rate is lower than the reference value (YES in step S32), the personal computer 40a issues an alert (S33).

  As described above, in the wireless sensor system 10a according to the present embodiment, in addition to the function of the wireless sensor system 10 in the first embodiment, the sensor values of the wireless sensor terminals 20d to 20f are newly detected by the sensor 23a. Every time, the transmission of the packet is repeated a predetermined number of times at a predetermined time interval. Then, the personal computer 40a counts the number of packets including the same data ID among the packets received from the first receiver 30a and the second receiver 30b, and receives the ratio of the counted number to the predetermined number of times Calculate the rate. For a plurality of packets containing the same data ID, only data in one packet is held.

  As a result, since transmission of a packet including the same sense value and data ID is repeated, even in the case where the radio wave condition is deteriorated, dropping of reception is suppressed. Furthermore, since the reception rate is calculated in real time during operation, the installation position and the number of installation of the first receiver 30a and the second receiver 30b can be easily optimized. Further, in the personal computer 40a, only the data in one packet among the plurality of packets containing the same data ID is held, so the data containing the same data ID is redundantly recorded, The compression of the storage capacity of the personal computer 40a is avoided.

  In addition, when repeating transmission of packets, the wireless sensor terminals 20d to 20f transmit packets after each of the packets in the repetition includes a transmission ID corresponding to the number of transmissions among the predetermined number of times.

  As a result, the personal computer 40a can determine that the reception has been missed not only for each data ID but also for each transmission ID in the same data ID by determining the transmission ID included in the received packet. Therefore, the time-series change of the reception state is detected with higher accuracy.

  Note that, in the present embodiment, the wireless sensor terminals 20d to 20f are grouped into m (<M) transmissions and transmitted in order to repeatedly transmit a packet including the same data ID M times. Grouping is not necessary. M repeated transmissions may be ungrouped, transmitted at equal time intervals, or at non-uniform time intervals, as long as they are distributed in time and transmitted as much as possible.

Third Embodiment
Next, a wireless sensor system according to Embodiment 3 will be described.

  FIG. 12 is a block diagram showing the configuration of a wireless sensor system 10b according to the third embodiment.

  The wireless sensor system 10b is a system that collects sense values detected by a sensor attached to a moving body, and includes a plurality of wireless sensor terminals 20d to 20f and a plurality of gateways (attached to each moving body (not shown)). The first gateway 50a and the second gateway 50b), the server 62, and the portable terminal 64 are provided. In the drawing, a plurality of gateways (first gateway 50 a and second gateway 50 b), a server 62, and the Internet 60, which is a communication network connecting the mobile terminals 64, are also illustrated.

  The wireless sensor terminals 20d to 20f are the same as those in the second embodiment.

  The first gateway 50a and the second gateway 50b have a function of uploading various management information to the server 62 in addition to the functions of the first receiver 30a and the second receiver 30b and the personal computer 40a in the second embodiment. That is, the first gateway 50a and the second gateway 50b wirelessly receive packets broadcasted from the wireless sensor terminals 20d to 20f as receivers, perform data processing and abnormality detection on the received packets as a host, and further The management information obtained by the data processing and the abnormality detection is uploaded to the server 62 via the Internet 60.

  The server 62 is a device that holds management information uploaded from the first gateway 50a and the second gateway 50b and provides management information to the portable terminal 64 via the Internet 60, and includes a CPU, a ROM, a RAM, a program and data. And a computer main body provided with a communication interface and the like connected to the first gateway 50a and the second gateway 50b via the Internet 60, an input device such as a display, a keyboard, and a mouse.

  The portable terminal 64 accesses the server 62 via the Internet 60, thereby browsing the management information held in the server 62 and notifying an abnormality (alert) detected by the first gateway 50a and the second gateway 50b. Is received via the server 62, for example, a smartphone or a tablet terminal.

  FIG. 13 is a block diagram showing the configuration of the first gateway 50a and the second gateway 50b in FIG. Each of the first gateway 50 a and the second gateway 50 b has the same configuration, and includes the antenna 51 and the communication / control circuit 52.

  The antenna 51 is an antenna suitable for a frequency band used to receive packets wirelessly transmitted from the wireless sensor terminals 20 d to 20 f.

  The communication / control circuit 52 is a circuit that controls wireless communication with the wireless sensor terminals 20 d to 20 f, data processing and error detection of packets acquired by wireless communication, and communication between networks with the server 62 via the Internet 60. There is a receiver 52a, a RAM 52b, a CPU 52c, a ROM 52d, and a wired I / O 52e.

  The receiving unit 52a is a circuit that takes out a data body (payload) by filtering and demodulating a high frequency signal received through the antenna 51 and recovering a packet, and then removing a header depending on the communication system. , According to the Bluetooth (registered trademark) communication scheme. The RAM 52 b is a memory that temporarily stores data. The ROM 52 d is a read only memory that holds programs and data. The CPU 52c executes a program stored in the ROM 52d while using the RAM 52b, thereby controlling the packet obtained by the receiving unit 52a to be transferred to the server 62 via the wired I / O 52e. The wired I / O 52 e is a communication interface that communicates with the server 62 via the Internet 60.

  Next, an operation (that is, a data collection method) of the wireless sensor system 10b according to the present embodiment configured as described above will be described.

  FIG. 14 is a flowchart showing the operation of the wireless sensor system 10b according to the third embodiment. Here, the operations of the wireless sensor terminals 20d to 20f, the plurality of gateways (the first gateway 50a and the second gateway 50b), the server 62, and the portable terminal 64, and the mutual exchange of data are shown.

  The operations of the wireless sensor terminals 20d to 20f are the same as those in the second embodiment (S40 to S50). That is, also in the present embodiment, the wireless sensor terminals 20d to 20f perform the same data ID and sense value a predetermined number of times (M times) at predetermined time intervals each time the sensor 23a newly detects a sense value. Repeated transmission of packets containing. At this time, when repeating transmission of packets, each of the wireless sensor terminals 20d to 20f includes a transmission ID corresponding to the number of transmissions of the predetermined number of times (M times) in each of the packets in the repetition, Send a packet However, in the present embodiment, not only the latest sense value (the “latest sense value” in the figure) but also the past sense is included in the transmitted packet as in the packet data structure example shown in FIG. The value ("previous sense value" in the figure) is included.

  On the other hand, the first gateway 50a and the second gateway 50b perform the same processing as the first receiver 30a, the second receiver 30b, and the personal computer 40a in the second embodiment (S30a to S33a, S30b to S33b).

  However, in addition to the processing in the second embodiment, the first gateway 50a and the second gateway 50b perform data processing (S31a, S31b) in the data processing (transmission ID, data ID, latest sense value). And the previous sense value), the reception rate, the presence or absence of reception failure, and the like are uploaded to the server 62 via the Internet 60 as management information. Furthermore, the first gateway 50a and the second gateway 50b issue an alert to the server 62 via the Internet 60 in the alert notification (S33a, S33b).

  On the other hand, the server 62 receives data (management information) uploaded from the first gateway 50a and the second gateway 50b via the Internet 60 (S60), performs data processing, and stores the data in the storage unit 62a. To do (S61).

  Further, when the server 62 receives an alert from the first gateway 50a and the second gateway 50b via the Internet 60, the server 62 transmits the alert to the portable terminal 64 via the Internet 60 (that is, issues an alert) (S62). ).

  On the other hand, the mobile terminal 64 accesses the server 62 via the Internet 60 according to the user's instruction, thereby browsing the management information held in the storage unit 62a of the server 62 (S70), the first gateway 50a, The notification (alert) of the abnormality detected by the second gateway 50b is received via the server 62 (S71).

  As described above, in the wireless sensor system 10b according to the present embodiment, unlike the first and second embodiments, the first gateway 50a and the second gateway 50b have not only functions as receivers but also data processing by the CPU 52c. And also has an abnormality detection function. That is, the first gateway 50a and the second gateway 50b separate the data ID, transmission ID, sense value, and the like from the received packet, and extract only one sense value corresponding to the specific data ID. The reception condition is determined from the ID, and the extracted sense value, data ID, and the determined reception condition are transmitted to the server 62. Thereby, even when the number of wireless sensor terminals becomes very large, the amount of data communicated between the first gateway 50a and the second gateway 50b and the server 62 is greatly reduced, and the communication load and the server 62 Processing load is reduced.

  Further, according to the wireless sensor system 10b according to the present embodiment, the user can collect from the wireless sensor terminals 20d to 20f using the portable terminal 64 at hand as long as the user is in an environment where the user can connect to the Internet 60. It is convenient that the user can browse the sensed value, browse management information such as the reception rate and missed reception, and receive alerts.

  The wireless sensor system, the wireless sensor terminal, and the data collection method according to the present invention have been described based on the first to third embodiments. However, the present invention is not limited to these embodiments. Without departing from the gist of the present invention, various modifications that may occur to those skilled in the art may be added to the embodiment, and other embodiments configured by combining some of the components in the embodiment are also within the scope of the present invention. include.

  For example, in the first to third embodiments, the wireless sensor terminals 20a to 20f measure the temperature using the thermistor. However, the temperature sensor is not limited to such a measurement, and is not limited to the humidity, blood pressure, atmospheric pressure, heart rate, and the like. A physical property value may be measured, a plurality of sensors may be provided to measure a plurality of physical property values, or different physical property values may be measured depending on the wireless sensor terminal. This makes it possible to collect and manage data according to various purposes.

  In the first to third embodiments, the wireless sensor terminals 20a to 20f are attached to a person as a mobile body. However, the mobile body to be attached is not limited to a person, and an animal, a car, or a movable equipment And so on, or may be attached to different types of mobiles by wireless sensor terminals.

  In the first to third embodiments, the wireless sensor terminals 20a to 20f transmit a packet including a data ID, a sense value, and the like. However, information included in the packet is not limited to these, and time information, wireless Identification information of the sensor terminal, information indicating the remaining amount of the battery 24, and the like may be included. Thus, the host that has acquired such a packet can manage other information together with the sense value.

  In the first and third embodiments, the wireless sensor terminals 20a to 20f include the “previous sense value” obtained in the previous measurement as the past sense value included in the packet. The sense value is not limited to the previous sense value. The packet may also include sense values obtained by a plurality of previous measurements, an average value of a predetermined number of past sense values, a data ID corresponding to the plurality of sense values, and the like. As a result, the host that has acquired such a packet can make a more detailed determination about missed reception and restore a past sense value that missed reception.

  In the first to third embodiments, the data ID is a sequential value starting from 1. However, the data ID is not limited to this, and any ID may be used as long as it is unique each time a sense value is newly detected by the sensor. It may be a numerical value starting from a numerical value and increasing or decreasing by an arbitrary value.

  The present invention relates to a wireless sensor terminal that is attached to a moving body and wirelessly transmits data including a sense value detected by a sensor, a wireless sensor system including the wireless sensor terminal, and a data collection method using the wireless sensor system For example, it can be used as a system for collecting biological information of a person from a wireless sensor terminal attached to the person.

10, 10a, 10b Wireless sensor system 20a to 20f Wireless sensor terminal 21 Antenna 22 Wireless communication / control circuit 22a Transmitter 22b RAM
22c CPU
22d ROM
23 measurement circuit 23a sensor 23b ADC
24 Battery 30 Receiver 30a First Receiver 30b Second Receiver 31 Antenna 32 Communication Circuit 32a Receiver 32b Wired I / O
40, 40a PC (personal computer)
50a first gateway 50b second gateway 51 antenna 52 communication / control circuit 52a receiver 52b RAM
52c CPU
52d ROM
52e Wired I / O
60 Internet 62 Server 64 Mobile terminal

Claims (4)

A wireless sensor terminal attached to a mobile body, having a sensor, and wirelessly transmitting data including a sense value detected by the sensor as a packet;
A receiver for wirelessly receiving the packet transmitted from the wireless sensor terminal;
A host for receiving the packet from the receiver;
Each time a sense value is newly detected by the sensor, the wireless sensor terminal stores data including the detected sense value, a unique data ID corresponding to the detection, and a sense value detected in the past. Broadcasting wirelessly as a packet is repeated a predetermined number of times at predetermined time intervals, and in the repetition, each of the packets includes a transmission ID corresponding to the number of transmissions of the predetermined number of times,
The host counts the number of packets including the same data ID among the packets received from the receiver, calculates a reception rate that is a ratio of the counted number to the predetermined number of times, The wireless sensor system which hold | maintains only the data in one packet about several said packets in which data ID is contained. Each time a sense value is newly detected by the sensor, the wireless sensor terminal further includes a data ID corresponding to the sense value detected in the past, and then transmits the packet. The wireless sensor system according to claim 1.   A wireless sensor terminal in the wireless sensor system according to claim 1. A data collection method by a wireless sensor system comprising a wireless sensor terminal attached to a mobile body, a receiver and a host,
A transmitting step in which the wireless sensor terminal wirelessly transmits data including a sense value detected by a sensor included in the wireless sensor terminal as a packet;
A receiving step in which the receiver wirelessly receives the packet transmitted from the wireless sensor terminal;
The host receiving and managing the packet from the receiver;
In the transmission step, each time a sense value is newly detected by the sensor, the wireless sensor terminal detects the detected sense value, a unique data ID corresponding to the detection, and a sense value detected in the past. Is repeatedly transmitted a predetermined number of times at predetermined time intervals, and in the repetition, each of the packets is transmitted with a transmission ID corresponding to the number of transmissions of the predetermined number Include
In the management step, the host counts the number of packets including the same data ID among the packets received from the receiver, and sets a reception rate which is a ratio of the counted number to the predetermined number of times. A data collection method for calculating and holding only data in one packet for a plurality of the packets including the same data ID.

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