JP2009169631A - Radio communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect attachment/detachment and failure of an external sensor without changing a communications protocol with the external sensor, and notify it to a sensor network autonomously. <P>SOLUTION: This radio communication terminal includes a terminal control part which connects the external sensor through a general-purpose interface part for data communications, a radio processing part which inputs the data output from the sensor through the terminal control part, converts the data into a radio signal and transmits the signal to the sensor network, a selector which is arranged between the general-purpose interface part and the terminal control part and connects the sensor and the terminal control part through the general-purpose interface part normally, a contact detection part which detects connection of the sensor through the general-purpose interface part, and a pseudo sensor which is connected to the selector and the contact detection part, and when detecting removal of the sensor after connection at the contact detection part, which switches the selector for connection to the terminal control part and transmits a predetermined message indicating removal of the sensor to the terminal control part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication terminal that wirelessly connects various sensors to a sensor network or the like.

  FIG. 8 shows a configuration example of a conventional wireless communication terminal. In the figure, a wireless communication terminal 10 manages a wireless processing unit 11 that wirelessly performs data communication with a base station of a sensor network (not shown), and manages terminal operations, and performs data communication with an external sensor 20 via a general-purpose interface unit 13. It is comprised from the terminal control part 12 which performs. Assuming that the sensor 20 is, for example, an electric meter or gas meter meter in a house or the like, a remote meter reading system in which the wireless communication terminal 10 connected to the meter meter wirelessly transmits meter reading data to the base station of the sensor network. Will be composed.

This remote meter reading system has the following two access procedures. One access procedure is a procedure in which a sensor (meter-reading device) autonomously makes a data transmission request, and the wireless communication terminal 10 that has received this makes a bandwidth allocation request to the sensor network and transmits meter-reading data (hereinafter referred to as a data transmission request). It is called “sensor opportunity”. In the other access procedure, a meter reading request is sent from the sensor network side to the sensor (meter reading device) via the wireless communication terminal 10, and meter reading data output by the sensor (meter reading device) responding thereto is transmitted from the wireless communication terminal 10. It is a procedure (hereinafter referred to as “network opportunity”).
Shin Toyoda, “Environmental Monitoring System Using Sensor Networks”, IEICE Journal Vol.89, No.5, 2006, pp.419-422

  The conventional wireless communication terminal 10 shown in FIG. 8 is configured to perform data communication with the sensor 20 according to a predetermined communication protocol at the timing of either the sensor trigger or the network trigger, and transmit the data of the sensor 20 to the sensor network. The wireless communication terminal 10 does not have a function of autonomously communicating with the sensor network side. Therefore, when the sensor 20 fails, the wireless communication terminal 10 cannot notify the failure of the sensor 20 because it cannot communicate with the sensor network side even if it detects the failure of the sensor 20. Further, even when the sensor 20 is removed or an unauthorized sensor is attached, the wireless communication terminal 10 cannot detect the situation and notify the sensor network side.

  An object of the present invention is to provide a wireless communication terminal that can detect attachment / detachment or failure of an external sensor and autonomously notify the sensor network side without changing a communication protocol with the external sensor. And

  The present invention provides a terminal control unit that performs data communication by connecting an external sensor via a general-purpose interface unit, and inputs data output from the sensor via the terminal control unit, converts the data into a radio signal, and converts the sensor network A wireless communication terminal including a wireless processing unit for transmitting to a selector, which is disposed between the general-purpose interface unit and the terminal control unit and normally connects the sensor and the terminal control unit via the general-purpose interface unit; A contact detection unit that detects whether or not a sensor is connected via the interface unit, and a selector that is connected to the selector and the contact detection unit, and detects that the sensor has been removed after being connected by the contact detection unit. And a pseudo sensor that transmits a predetermined message indicating the removal of the sensor to the terminal control unit. It sends a predetermined message to be input from the data as well as a pseudo sensor input from sensor to the wireless processing unit, a configuration to transmit is converted into a radio signal.

  The contact detection unit in the wireless communication terminal of the present invention has an electrode that forms a closed circuit when the connector on the wireless communication terminal side of the general-purpose interface unit and the connector on the sensor side are connected. In this configuration, the formation of the closed circuit is electrically detected to recognize the connection of the sensor, and the removal of the sensor is recognized when it is electrically detected that the contact detection unit has become an open circuit after the closed circuit is formed.

  The pseudo sensor in the wireless communication terminal according to the present invention monitors the remaining amount of the battery that supplies power to the wireless communication terminal, and switches the selector when detecting that the remaining battery level is equal to or less than the predetermined value. And a means for transmitting a predetermined message indicating the remaining battery level to the terminal control unit.

  The pseudo sensor in the wireless communication terminal of the present invention monitors the temperature of the wireless communication terminal, and when it detects that the temperature of the wireless communication terminal is equal to or higher than a predetermined value, switches the selector to connect to the terminal control unit, You may make it include the means to transmit the predetermined | prescribed message which shows abnormality of a radio | wireless communication terminal to a terminal control part.

  The pseudo sensor in the wireless communication terminal of the present invention monitors the amount of data output from the sensor to the terminal control unit, and switches the selector when detecting that the amount of data within a predetermined time is less than or equal to a predetermined value. A means for connecting to the terminal control unit and transmitting a predetermined message indicating a sensor failure to the terminal control unit may be included.

  Further, the wireless communication terminal of the present invention connects the terminal control unit and the pseudo sensor via a control line different from the route through the selector, and the pseudo sensor electrically detects the formation of the closed circuit of the contact detection unit. When the terminal control unit electrically detects that the contact detection unit has become an open circuit after the closed circuit is formed, the terminal control unit recognizes the removal of the sensor by a notification from the pseudo sensor, and performs processing corresponding to the pseudo sensor. It may be configured to instruct. Furthermore, instead of the process in which the pseudo sensor transmits a predetermined message to the terminal control unit via the selector, the pseudo sensor may directly write the predetermined message in the storage unit of the terminal control unit under the control of the terminal control unit. .

  The wireless communication terminal of the present invention includes a pseudo sensor that simulates an external sensor, and when the pseudo sensor detects the removal or failure of the external sensor, the pseudo sensor triggers notification of the fact. Message can be sent. In addition, the wireless communication terminal of the present invention may transmit a corresponding predetermined message triggered by the pseudo sensor when the pseudo sensor detects a remaining battery level or an abnormality in the temperature of the wireless communication terminal. it can. At this time, the pseudo sensor transmits a message corresponding to the communication protocol between the wireless communication terminal and the external sensor, so that the wireless communication terminal can receive the message from the pseudo sensor without changing the communication protocol with the external sensor. The message can be processed.

  In addition, the wireless communication terminal of the present invention acquires external sensor attachment / detachment and other information from the pseudo sensor, and controls to transmit a corresponding message from the pseudo sensor, or directly acquires a corresponding message from the pseudo sensor. By doing so, an external sensor and other information can be promptly transmitted to the sensor network.

(First embodiment)
FIG. 1 shows a first embodiment of a wireless communication terminal of the present invention.
In FIG. 1, a wireless communication terminal 10 includes a wireless processing unit 11 and a terminal control unit 12 as in the conventional configuration shown in FIG. 8, and is configured to connect an external sensor 20 via a general-purpose interface unit 13. In the terminal control unit 12, a RAM 122, a ROM 123, and an I / O 124 are bus-connected to the CPU 121, and the I / O 124 and the general-purpose interface unit 13 are connected. As the general-purpose interface unit 13, for example, a serial interface such as RS232C or USB (Universal Serial Bus) can be used, but is not limited thereto.

  A feature of this embodiment is that a selector 14 is inserted between the I / O 124 of the terminal control unit 12 and the general-purpose interface unit 13, and a pseudo sensor 15 simulating an external sensor 20 is connected to the selector 14. That is, the external sensor 20 or the internal pseudo sensor 15 is alternatively connected to the terminal control unit 12 via the selector 14, but the selector 14 usually connects the external sensor 20 to the terminal control unit 12. Set to connect.

  The connector of the general-purpose interface unit 13 is provided with a contact detection unit 16 that detects when an external sensor 20 is connected. The contact detection unit 16 includes two electrodes 1 and 2 connected to the pseudo sensor 15 and an electrode 3 that short-circuits the electrodes 1 and 2 when the connector of the general-purpose interface unit 13 is connected.

FIG. 2 shows a configuration example of the general-purpose interface unit 13 and the contact detection unit 16.
In FIG. 2 (1), the general-purpose interface unit 13 is provided with electrodes 1 and 2 on a connector 17 on the wireless communication terminal side as a contact detection unit 16 independently of a serial interface for connecting the wireless communication terminal and an external sensor. The electrode 3 is provided on the connector 21 on the external sensor side, and when the connectors 17 and 21 are connected, the electrodes 1, 2 and 3 constitute a closed circuit. Here, the pin of the connector 21 on the sensor side is pushed in when connecting to the connector 17 on the wireless communication terminal side.

  In FIG. 2 (2), the general-purpose interface unit 13 is connected to a connector 17 on the wireless communication terminal side as electrodes 1, 2, and 2 as a contact detection unit 16 independently of a serial interface for connecting the wireless communication terminal and an external sensor. 3 and when the connectors 17 and 21 are connected, the electrodes 1, 2 and 3 constitute a closed circuit. Here, the pin of the connector 21 on the sensor side is inserted when connecting to the connector 17 on the wireless communication terminal side, and one pin pushes the electrode 3 to short-circuit the electrodes 1 and 2.

  The function of the pseudo sensor 15 will be described with reference to FIG. The pseudo sensor 15 includes a potential detection unit that detects the potential of the contact detection unit 16, and a control unit that switches the selector 14 according to the potential change and outputs a predetermined message stored in the register to the terminal control unit 12. Prepare. For example, the potential detection unit applies a voltage to the electrode 1 to monitor the voltage of the electrode 2. When the voltage of the electrode 2 is not detected, the external sensor 20 recognizes that the external sensor 20 is not connected, and the external sensor 20 is connected. Thus, when the electrodes 1, 2, and 3 form a closed circuit and the same voltage as that of the electrode 1 is detected from the electrode 2, it is recognized that the external sensor 20 is connected.

  Here, when the potential detection unit of the pseudo sensor 15 recognizes that the external sensor 20 is connected, the control unit of the pseudo sensor 15 shifts to the sensor connection mode, and then the voltage of the electrode 2 decreases in the potential detection unit. If it is detected that the external sensor 20 has been removed, it is recognized that the external sensor 20 has been removed. As a result, it is possible to distinguish and detect a state in which the external sensor 20 is not connected and a state in which the external sensor 20 is once connected and then removed.

  When the control unit of the pseudo sensor 15 recognizes that the external sensor 20 has been removed after being once connected, the control unit 14 switches the selector 14 from the general-purpose interface unit 13 to the pseudo sensor 15, and predefines the data defined by the user. Using a pattern or the like, a predetermined message indicating that the external sensor 20 has been removed is output. The terminal control unit 12 receives the predetermined message output from the pseudo sensor 15, processes it in the same manner as the input data from the external sensor 20, and transmits it as a wireless signal from the wireless processing unit 11 to the sensor network side.

  As described above, when the external sensor 20 is removed, the pseudo sensor 15 can be notified of the fact to the sensor network side. However, unlike the external sensor 20, the pseudo sensor 15 does not need to implement a communication protocol with the wireless communication terminal 10, and has a function of outputting a predetermined message stored in the register to the terminal control unit 12. Because it is good, it can be realized with extremely small hardware.

  The predetermined message is a message or signal in a format defined in the communication protocol between the sensor network base station and the sensor 20, and is mainly used to notify the sensor network base station of the status of the sensor 20. is there. The pseudo sensor 15 may transmit a message or signal in the same format as the external sensor 20, and in this embodiment, the pseudo sensor 15 is a message notifying that the external sensor 20 has been removed. The data format in the message may be in accordance with the specifications of the application for the base station of the sensor network to collect and analyze the sensor data.

(Second Embodiment)
FIG. 3 shows a second embodiment of the wireless communication terminal of the present invention.
In FIG. 3 (1), the wireless communication terminal 10 of the present embodiment includes a battery remaining amount monitor unit of a battery 18 serving as a power supply source of the wireless communication terminal 10 in addition to the configuration of the first embodiment. It is characterized by providing. When the control unit of the pseudo sensor 15 detects that the remaining battery level is equal to or less than a predetermined value via the remaining battery level monitoring unit, the control unit 14 switches the selector 14 from the general-purpose interface unit 13 to the pseudo sensor 15 and notifies that effect. A predetermined message is output. The terminal control unit 12 inputs a predetermined message output from the pseudo sensor 15, processes it in the same manner as the input data from the external sensor 20, and notifies the wireless network from the wireless processing unit 11 to the sensor network side. As described above, when the remaining battery level of the wireless communication terminal 10 is reduced, the pseudo sensor 15 can be used as an opportunity to notify the sensor network side of the fact.

  As shown in FIG. 3 (2), the battery remaining amount monitor section includes a plurality of types of reference voltage sources ref1 to ref3, and each of the remaining battery amounts is compared with the output voltage of the battery 18 by a plurality of comparators. The level may be detected, and the control unit of the pseudo sensor 15 may output a message corresponding to each remaining battery level.

(Third embodiment)
FIG. 4 shows a third embodiment of the wireless communication terminal of the present invention.
4, in addition to the configuration of the first embodiment, the wireless communication terminal 10 of the present embodiment includes a temperature monitor unit that connects the temperature sensor 19 to the pseudo sensor 15 and monitors the temperature of the wireless communication terminal 10. It is characterized by that. When the control unit of the pseudo sensor 15 detects that the temperature of the wireless communication terminal 10 has risen abnormally via the temperature monitor unit, the control unit 14 switches the selector 14 from the general-purpose interface unit 13 to the pseudo sensor 15 to indicate the fact. A predetermined message is output. The terminal control unit 12 inputs a predetermined message output from the pseudo sensor 15, processes it in the same manner as the input data from the external sensor 20, and notifies the wireless network from the wireless processing unit 11 to the sensor network side. Thus, when the temperature of the wireless communication terminal 10 rises abnormally due to the occurrence of a fire or the like, the pseudo sensor 15 can be used as a trigger to notify the sensor network side of that fact.

(Fourth embodiment)
FIG. 5 shows a fourth embodiment of the wireless communication terminal of the present invention.
In FIG. 5, in addition to the configuration of the first embodiment, the wireless communication terminal 10 of the present embodiment connects the output of the selector 14 to the pseudo sensor 15 and is output from the external sensor 20 to the wireless communication terminal 10. A data monitoring unit that counts the data amount at regular time intervals is provided. The control unit of the pseudo sensor 15 determines that the external sensor 20 is out of order when the count value of the data monitor unit is equal to or smaller than a predetermined value, and switches the selector 14 from the general-purpose interface unit 13 to the pseudo sensor 15, and indicates that fact Message is output. The terminal control unit 12 inputs a predetermined message output from the pseudo sensor 15, processes it in the same manner as the input data from the external sensor 20, and notifies the wireless network from the wireless processing unit 11 to the sensor network side. In this way, when the external sensor 20 fails, the pseudo sensor 15 can be used as an opportunity to notify the sensor network side of the failure.

  Each function of the pseudo sensor 15 shown in the above second to fourth embodiments may be individually combined with the configuration of the first embodiment, or the pseudo sensor 15 combines a plurality of functions. You may make it have.

(Fifth embodiment)
The pseudo sensor 15 in the first to fourth embodiments independently monitors the connection state between the wireless communication terminal 10 and the external sensor 20 and can operate autonomously with respect to the terminal control unit 12. Yes.

  1, 3, 4, and 5, the CPU 121 of the terminal control unit 12 and the pseudo sensor 15 are connected by a bus, and part of the control operation of the pseudo sensor 15 is performed by the terminal control unit 12. You may make it perform.

  For example, as illustrated in FIG. 6, the terminal control unit 12 transitions to the initial mode when the wireless communication terminal 10 is turned on, and then transitions to the sensor connection waiting mode. On the other hand, when the potential detection unit of the pseudo sensor 15 recognizes that the external sensor 20 is connected, it notifies the terminal control unit 12. When the terminal control unit 12 recognizes that the external sensor 20 is connected, the terminal control unit 12 transits to the sensor connection mode and enters a communication sequence using a specific communication protocol with the external sensor 20. When the pseudo sensor 15 detects that the voltage of the electrode 2 has been reduced by the potential detection unit and notifies the terminal control unit 12, the terminal control unit 12 recognizes that the external sensor 20 has been removed and removes the sensor. The mode is changed, the selector 14 is switched to the pseudo sensor 15, and control is performed so as to transmit a predetermined message.

(Sixth embodiment)
In the first to fourth embodiments, the external sensor 20 connected to the wireless communication terminal 10 and the internal pseudo sensor 15 are in parallel, and the terminal control unit 12 of the wireless communication terminal 10 is output from both. The same data may be processed in the same way. That is, the format of the predetermined message output from the pseudo sensor 15 is in accordance with the communication protocol defined between the terminal control unit 12 and the external sensor 20, and is output from the external sensor 20. Data and messages output from the pseudo sensor 15 are processed according to the same communication protocol.

  On the other hand, as shown in FIG. 7, the pseudo-sensor 15 and the register (RAM 122) of the terminal control unit 12 are directly connected, and the communication protocol (interface) defined between the terminal control unit 12 and the external sensor 20 is defined. The content of data transmitted from the pseudo sensor 15 may be directly set in the register under the control of the terminal control unit 12 without using the control. Thereby, the pseudo sensor 15 and the terminal control unit 12 do not need to interpret the message, and it is possible to promptly notify the sensor network of necessary information. At this time, the pseudo sensor 15 controls the selector 14 so that the signal from the external sensor 20 is cut off.

The figure which shows 1st Embodiment of the radio | wireless communication terminal of this invention. FIG. 3 is a diagram illustrating a configuration example of a general-purpose interface unit 13. The figure which shows 2nd Embodiment of the radio | wireless communication terminal of this invention. The figure which shows 3rd Embodiment of the radio | wireless communication terminal of this invention. The figure which shows 4th Embodiment of the radio | wireless communication terminal of this invention. The figure which shows 5th Embodiment of the radio | wireless communication terminal of this invention. The figure which shows 6th Embodiment of the radio | wireless communication terminal of this invention. The figure which shows the structural example of the conventional radio | wireless communication terminal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wireless communication terminal 11 Wireless processing part 12 Terminal control part 13 General-purpose interface part 14 Selector 15 Pseudo sensor 16 Contact detection part 17 Connector on the wireless communication terminal side 18 Battery 19 Temperature sensor 20 Sensor 21 Connector on the sensor side

Claims (7)

A terminal control unit that performs data communication by connecting an external sensor via a general-purpose interface unit;
In a wireless communication terminal comprising: a wireless processing unit that inputs data output from the sensor through the terminal control unit, converts the data into a wireless signal, and transmits the wireless signal to a sensor network;
A selector that is disposed between the general-purpose interface unit and the terminal control unit and normally connects the sensor and the terminal control unit via the general-purpose interface unit;
A contact detection unit for detecting whether or not the sensor is connected via the general-purpose interface unit;
Connected to the selector and the contact detection unit, and when the contact detection unit detects that the sensor has been removed and then removed, the selector is switched to connect to the terminal control unit, and the sensor is removed. A pseudo sensor that transmits a predetermined message indicating to the terminal control unit,
The terminal control unit is configured to send a predetermined message input from the pseudo sensor to the wireless processing unit in the same manner as data input from the sensor, and convert the wireless message into a wireless signal for transmission. Communication terminal. The wireless communication terminal according to claim 1,
The contact detection unit has an electrode that forms a closed circuit when connecting the connector on the wireless communication terminal side of the general-purpose interface unit and the connector on the sensor side,
The pseudo sensor electrically detects the formation of a closed circuit of the contact detection unit, recognizes the connection of the sensor, and electrically detects that the circuit has been opened after forming the closed circuit of the contact detection unit. A wireless communication terminal characterized by being configured to recognize the removal of the sensor sometimes. In the wireless communication terminal according to claim 1 or 2,
The pseudo sensor monitors the remaining amount of a battery that supplies power to the wireless communication terminal, and switches the selector to connect to the terminal control unit when it detects that the remaining battery level is a predetermined value or less. And a means for transmitting a predetermined message indicating the remaining battery level to the terminal control unit. In the wireless communication terminal according to claim 1 or 2,
The pseudo sensor monitors the temperature of the wireless communication terminal and, when detecting that the temperature of the wireless communication terminal has reached a predetermined value or more, switches the selector to connect to the terminal control unit, and A wireless communication terminal comprising means for transmitting a predetermined message indicating an abnormality of the communication terminal to the terminal control unit. In the wireless communication terminal according to claim 1 or 2,
The pseudo sensor monitors the amount of data output from the sensor to the terminal control unit, and switches the selector to detect the terminal control when detecting that the amount of data within a predetermined time is less than or equal to a predetermined value. A wireless communication terminal comprising: means for connecting to the terminal and transmitting a predetermined message indicating a failure of the sensor to the terminal control unit. In the radio | wireless communication terminal in any one of Claims 1-5,
When the terminal control unit and the pseudo sensor are connected via a control line different from the path through the selector, and the pseudo sensor electrically detects the formation of a closed circuit of the contact detection unit, the contact When it is electrically detected that the open circuit has been formed after forming the closed circuit of the detection unit, the terminal control unit recognizes the removal of the sensor by a notification from the pseudo sensor, and performs processing corresponding to the pseudo sensor. A wireless communication terminal characterized by being configured to instruct. The wireless communication terminal according to claim 6, wherein
Instead of the process in which the pseudo sensor transmits the predetermined message to the terminal control unit via the selector, the pseudo sensor sends the predetermined message to the storage unit of the terminal control unit under the control of the terminal control unit. A wireless communication terminal characterized by direct writing.

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