JP2007122550A - Sensor terminal, sensor net system and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized sensor terminal easy to maintain, and to provide a sensor net system with a simple structure, which is easy to set in various conditions such as natural disaster prior sensing, and its control method. <P>SOLUTION: This sensor terminal comprises an observation apparatus 1 detecting a physical quantity at an observation point, a CPU part 2 performing analog signal processing to a sensor signal from the observation apparatus 1 followed by A/D conversion to generate a digital data signal; a radio part 3 transmitting the digital data signal wirelessly from the CPU part 2 to the other point and relaying a digital data signal obtained at another observation point; and a power supply part 4 supplying power for driving the observation apparatus 1, the CPU part 2 and the radio part 3, which are formed as an integrated unit. The power supply part 4 comprises a solar battery, an electric double layer capacitor, a lithium ion battery, and a DC-DC converter. The sensor net system for natural disaster prior sensing or the like is constituted by using this sensor terminal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor terminal, a sensor network system, and a control method thereof, and in particular, a sensor terminal suitable for use in a wireless network system or device, an unmanned monitoring system or device, and a sensor for sensing natural disasters in advance using the sensor terminal. The present invention relates to a network system and a control method thereof.

  As a natural disaster prior detection device that can detect and notify a natural disaster caused by an earthquake or a typhoon in advance in the prior art, for example, there is a sediment disaster prior detection alarm system and a debris flow detection device disclosed in Patent Document 1. This debris disaster pre-sensing device uses a debris flow detection device using a tube switch, and when debris flow caused by a ground fault passes through the tube switch, the debris flow output by the tube switch being crushed by the depressing force of this debris flow Based on the detection signal, it is possible to detect the occurrence of ground abnormality.

  On the other hand, as sensor terminals used in wireless network systems or devices, unmanned monitoring systems or devices, etc., a sensor unit that detects physical data and performs data correction processing, a CPU unit that performs A / D conversion and calculation processing, and measurement data There is known a radio unit that transmits a power source and a power source unit that supplies power to these units (for example, Patent Document 2). The conventional sensor terminal used for it supplies a power supply to a sensor part, a CPU part, and a radio | wireless part using a coin-type battery or a solar cell as a power supply part.

JP 2003-6775 A JP 2004-355165 A

  However, the natural disaster pre-sensing device disclosed in Patent Document 1 is a large-scale terminal device that detects changes in the observation location. In addition, a point where a natural disaster is likely to occur may be difficult for an apparatus installation worker to perform the work, and may be exposed to a risk of a disaster in some cases. Therefore, it is not easy to urgently install the terminal device at an observation site where natural disasters are likely to occur.

  In addition, the detection data is transmitted and received between the slave station, the observation station, and the monitoring station by wireless communication. However, the terminal device installed at the observation site is a large-scale device composed of a solar cell, a wireless communication unit, and the like. Installation cost is high.

  In this situation, a first object of the present invention is to provide a sensor network system that can be easily installed for various conditions such as for natural disaster pre-sensing and a control method thereof with a simple configuration.

  On the other hand, conventional sensor terminals use a low-power wireless communication system called ZigBee (registered trademark) or specific low-power, and use a low-power CPU, but the sensor network terminal using a coin-type battery is downsized. Although it is possible, there was a limitation on the operation time by the power source. Moreover, in the sensor terminal using a solar cell, since the electrical conversion efficiency of a solar cell is bad, it is necessary to enlarge a solar cell panel, and although there was no restriction | limiting of the operation time by a power supply, size reduction could not be achieved.

  In addition, the conventional sensor terminal centrally manages only physical data sensed by the sensor through the network, but does not monitor the power supply voltage of the terminal itself and manage the operation status of the terminal, There was a need to periodically maintain the power supply.

  In this situation, a second problem of the present invention is to provide a sensor terminal that is small and easy to maintain.

  The present invention is a sensor terminal that does not require human work for replacement and recharging of a battery constituting a power supply unit, and is a sensor unit that detects physical data, and performs analog signal processing on the sensor signal to perform A / D conversion. A CPU unit for performing the operation, a wireless unit for wirelessly transmitting a digital data signal to each terminal, and a power source unit for supplying power for driving each block of the terminal, wherein the power source unit is a private power generation block, a power conversion block, and a power storage block The sensor terminal has a stabilized power supply block and does not require human work for replacement and recharging of the battery constituting the power supply unit. The present invention also provides a sensor network system and a control method thereof for performing natural disaster prior detection using the sensor terminal.

  That is, the sensor terminal of the present invention includes a sensor unit that detects a physical quantity at an observation point, a CPU unit that performs analog signal processing on the sensor signal from the sensor unit, performs A / D conversion, and generates a digital data signal; A wireless unit that transmits a digital data signal from the CPU unit to another wirelessly and relays a digital data signal obtained at another observation point, and drives the sensor unit, the CPU unit, and the wireless unit. A power supply unit that supplies power, the power supply unit having a private power generation block, a power conversion block, a power storage block, and a stabilized power supply block, the self power generation block being a solar cell, the power The conversion block is an electric double layer capacitor, the storage block is a lithium ion battery, and the stabilized power supply block Wherein the DC-DC converter is used in Te.

  The CPU unit may have a function of monitoring a power supply voltage of the power supply unit and generating digital data thereof, and the digital data of the power supply voltage may be transmitted via the wireless unit.

  The sensor terminal may be formed integrally.

  The sensor network system of the present invention is characterized in that the sensor terminal is used and includes means for centrally managing the physical quantity and centrally managing the power supply voltage.

  The observation point is a point where there is a risk of a natural disaster, and the sensor unit includes an acceleration sensor, and the sensor for collecting the observation information used for predicting the abnormality of the observation point and performing natural disaster prior detection It should be a net system.

  The sensor network system control method of the present invention is the sensor network system control method, wherein the observation information is transmitted by relay transmission / reception between the sensor terminals.

  As described above, according to the present invention, a sensor network system using a small and light sensor terminal and having a low installation cost is possible. Furthermore, since a small and lightweight sensor terminal is used, it is possible to provide a sensor network system for detecting natural disasters in advance and a control method thereof that can be easily installed at an observation site where there is a risk of natural disasters.

  In addition, according to the present invention, it is possible to configure a sensor terminal that is small and has no limitation on the operation time by the power supply unit. Furthermore, it is possible to configure a small sensor terminal that is easy to maintain by centrally managing the power supply voltage of the terminal and confirming the operation status.

  Conventionally, the observation device and the control unit are separated from each other, and each of them must be installed at an observation site, and many support tables and support members are required for installation. However, according to the present invention, since the observation device, the radio unit, the CPU unit, and the power supply unit are integrated, the number of installation work steps can be greatly reduced and the number of support bases and support members can be reduced. .

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an outline of a sensor terminal of the present invention. FIG. 2 is a block diagram showing an outline of a power supply unit according to the sensor terminal of the present invention.

  As shown in FIG. 1, the sensor terminal of the present invention includes an observation device 1, which is a sensor unit, a CPU unit 2, a radio unit 3, a power supply unit 4, and an antenna 5. The observation device 1 detects physical data. The CPU 2 performs analog signal processing on the observation signal from the observation device 1 to perform A / D conversion. The wireless unit 3 wirelessly transmits the digital data signal from the CPU unit 2 to another sensor terminal or base station, and further relays the digital data signal transmitted from the other sensor terminal to another terminal or base station. It has the function to do. Furthermore, the power supply unit 4 has a function of supplying power for driving the sensor unit, the CPU unit, and the wireless unit.

  As shown in FIG. 2, the power supply unit of the sensor terminal of the present invention includes a private power generation block, a power conversion block, a power storage block, and a stabilized power supply block. Consists of an electric double layer capacitor 7, a lithium ion battery 9 as a secondary battery having a high energy density as a storage block, and a DC-DC converter 10 as a stabilized power supply block. In addition, a charging control circuit 8 is placed immediately before the lithium ion battery 9.

  Here, when a solar cell is used for the sensor terminal of the sensor network system, since the solar cell has high impedance, the secondary battery cannot be charged efficiently, and a large area solar cell panel is required for charging. Miniaturization is difficult.

  Therefore, in the embodiment of the present invention, an electric double layer capacitor having a low impedance is inserted between the solar cell panel and the lithium ion battery. At this time, since the electric double layer capacitor has a low impedance, it can efficiently store the electricity generated by the solar cell panel. As for the flow of charging, the electricity generated by the solar panel is stored once in the electric double layer capacitor and the lithium ion battery is charged, but since it can be charged efficiently, the area of the solar panel can be reduced, and it is compact It is possible to realize a natural disaster pre-sensing device that can be realized.

  This will be described in detail with reference to the drawings. FIG. 5 shows the relationship between the voltage of the electric double layer capacitor and the charging current of the lithium ion battery during charging of the lithium ion battery in the sensor terminal of the present invention, and FIG. FIG. 5 (b) is a graph showing the time change of the electric double layer capacitor voltage. As shown in FIG. 5B, the process of once storing electricity generated by the solar cell in the electric double layer capacitor and then sending the charging current to the lithium ion battery in a pulsed manner is repeated. By doing so, electricity generated by the solar cell can be efficiently stored. Therefore, the area of the solar cell panel can be reduced, and a sensor terminal that can be miniaturized can be realized.

  Furthermore, the observation device (sensor unit) of the sensor terminal for natural disaster pre-sensing according to the present invention uses the small acceleration sensor produced by using a semiconductor MEMS (Micro-Electro-Mechanical Systems) process, thereby observing the device itself. And a small natural disaster pre-sensing sensor terminal that integrates the observation device, CPU unit, radio unit, and power supply unit.

  Further, when this power supply voltage is input to the CPU section and monitored, and the power supply of each terminal is managed via the wireless communication network, maintenance is easy because centralized management is performed even if the terminal is damaged. In addition, when centrally managing observation data and power supply voltage data with a base station computer, as shown in FIG. 3, the wireless communication network is realized by relay transmission between devices, thereby reducing the transmission output of radio waves and saving power. It becomes possible to do. This power saving contributes to the reduction of the solar cell panel and overall outer dimensions of each sensor terminal.

  Next, an example in which the present invention is implemented in a sensor network system and a sensor terminal for natural disaster pre-detection due to an earthquake or a typhoon will be described.

  In this example, a cube-shaped sensor terminal was manufactured as a natural disaster pre-sensing sensor terminal. FIG. 4 is an internal perspective view showing the configuration of the sensor terminal (active wireless sensor terminal) of the present embodiment. As shown in FIG. 4, the outer dimensions are a width dimension a of 30 mm, a depth dimension b of 30 mm, and a height dimension c of 30 mm (30 × 30 × 30 mm cube). In addition, from the top, the solar cell panel 23, the A substrate (first substrate) 24, the B substrate (second substrate) 25, the C substrate (third substrate) 26, the sensor mounting substrate (fourth). 27) are assembled in order through support columns. The power supply unit 31 includes an A substrate 24, a B substrate 25, and a C substrate 26. The A substrate 24 is a power conversion substrate on which the electric double layer capacitor 28 is mounted. The B substrate 25 is a substrate that controls charging. The C substrate 26 is a substrate for output, and is mounted with a lithium ion battery 29 and a DC-DC converter. On the sensor mounting board 27 at the bottom, an acceleration sensor as an observation device (sensor unit), a CPU unit, and a radio unit are mounted. An antenna 30 is provided on the back surface of the sensor mounting board 27 on which an observation device or the like is mounted. The solar cell panel and each substrate have a width of 30 mm, a depth of 30 mm, a height of 2 mm, and a flat plate shape. In this way, a small and light integrated sensor terminal could be realized.

  The sensor terminal of the present invention can be variously modified without departing from the scope of the present invention. For example, in the above embodiment, the outer shape is a cubic shape, but it is also possible to arrange each substrate in a planar shape to have a planar shape. Alternatively, the solar cell panel surface can be inclined to easily receive sunlight.

  The sensor network system for natural disaster pre-sensing according to the first embodiment of the present invention is configured using the sensor terminal thus manufactured. This sensor network system is installed in an observation site where there is a risk of ground anomalies such as landslides, landslides, and depressions. It has a function to transmit and receive prediction information and observation information using communication. Specifically, the ground inclination change and acceleration caused by landslides, landslides, and depressions are detected by an acceleration sensor as an observation device, and the observation information is transmitted and received using wireless communication.

  Here, there is a risk that equipment installation workers and the like may enter an observation site where there is a risk of ground abnormalities such as landslides, landslides, and depressions. Furthermore, installation of a large-scale device at the observation site may induce natural disasters such as landslides, making it difficult to install the device. Therefore, the sensor terminal for natural disaster pre-sensing of the present invention is small in size because the observation device, CPU unit, radio unit, and power supply unit are integrated, so that the device is installed in the observation site where there is a risk of ground abnormality such as landslides. An operator can easily install the apparatus. In addition, as shown in FIG. 6, installation is performed at an observation site where it is difficult for an operator to install the device by air spraying using a radio control helicopter or an air gun. That is, FIG. 6 is a diagram showing an example of aerial dispersion of sensor terminals in the sensor network system for natural disaster pre-sensing of the present embodiment, where 32 is an observation site, 34 is a sensor terminal, 33 is a radio control helicopter, and 35 is a base station. It is. The state of the aerial spray is indicated by dotted arrows.

  Next, a sensor network system for natural disaster pre-sensing according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a view showing an example of installation of a sensor network system for natural disaster pre-sensing in a present embodiment in a river, 36 is a river, 37 is a sensor terminal, and 22 is a base station. A thick arrow represents wireless communication.

  As shown in FIG. 7, the sensor terminal of this embodiment is installed on the water surface of a river or the like where there is a risk of flooding, and it collects the observation information and means for detecting observation information used for predicting an abnormality in the water surface displacement. And has a function of transmitting and receiving prediction information and observation information using wireless communication. Specifically, the natural disaster prior detection sensor terminal of the present invention floats on the surface of the water and detects the acceleration when the water surface changes with an acceleration sensor, which is an observation device, and transmits and receives the observation information using a wireless communication network. In addition, since the sensor terminal used by a present Example is small and lightweight and integrated as mentioned above, it became possible to float on the water surface using a simple apparatus.

  As described above, the sensor terminal of the present invention is a small, lightweight, power-saving, integrated terminal that is easy to maintain. By using this sensor terminal, a sensor network system that centrally manages various physical data in various installation forms becomes possible.

The block diagram which shows the outline of the sensor terminal of this invention. The block diagram which shows the power supply part outline which concerns on the sensor terminal of this invention. The figure which shows the radio | wireless communication network structure of the sensor network system for natural disaster prior detection of this invention. The perspective view which saw through the inside of the sensor terminal of one Example of this invention. The relationship between the electric double layer capacitor voltage and the charging current of the lithium ion battery during charging of the lithium ion battery in the sensor terminal of the present invention is shown. FIG. 5 (a) is a diagram of the time change of the charging current of the lithium ion battery. (B) is a figure of the time change of the voltage of an electric double layer capacitor. The figure which shows the example of aerial spraying of the sensor terminal in the sensor network system for natural disaster prior detection of one Example of this invention. The figure which shows the example of installation to the river of the sensor network system for natural disaster prior detection in the other Example of this invention.

Explanation of symbols

1 Observation equipment (sensor part)
2 CPU section 3 Radio section 4, 31 Power supply section 5, 30 Antenna 6, 23 Solar cell panel 7, 28 Electric double layer capacitor 8 Charge control circuit 9, 29 Lithium ion battery 10 DC-DC converter 21, 34, 37 Sensor terminal 22, 35, 38 Base station 24 A board 25 B board 26 C board 27 Sensor mounting board 32 Observation site 33 Radio control helicopter 36 River a Width dimension b Depth dimension c Height dimension

Claims (6)

A sensor unit that detects physical quantities at the observation point;
A CPU unit that performs analog signal processing on the sensor signal from the sensor unit and performs A / D conversion to generate a digital data signal;
A wireless unit that wirelessly transmits the digital data signal from the CPU unit to the other and relays the digital data signal obtained at another observation point;
A sensor terminal comprising: a power supply unit that supplies power for driving the sensor unit, the CPU unit, and the wireless unit;
The power supply unit includes a private power generation block, a power conversion block, a power storage block, and a stabilized power supply block. The self power generation block is a solar cell, the power conversion block is an electric double layer capacitor, and the power storage block is lithium. A sensor terminal, wherein a DC-DC converter is used as the ion battery and the stabilized power supply block.   2. The CPU unit has a function of monitoring a power supply voltage of the power supply unit and generating digital data thereof, and the digital data of the power supply voltage is transmitted via the wireless unit. The described sensor terminal.   The sensor terminal according to claim 2, wherein the sensor terminal is integrally formed.   4. The sensor network system according to claim 2, further comprising means for centrally managing the physical quantity and centrally managing the power supply voltage.   The observation point is a point where there is a risk of a natural disaster, and the sensor unit includes an acceleration sensor, and collects observation information used for predicting an abnormality of the observation point and performs natural disaster pre-sensing. The sensor network system according to claim 4.   6. The sensor network system control method according to claim 5, wherein the observation information is transmitted by relay transmission / reception between the sensor terminals.

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