SENSOR NETWORK SYSTEM

• US 20150257203A1
• Filed: 09/06/2013
• Published: 09/10/2015
• Est. Priority Date: 10/18/2012
• Status: Active Grant

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan), Micromachine Center
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan), Micromachine Center
• Inventors: Sakamizu, Toshio, Okada, Hironao, Itoh, Toshihiro, Arakawa, Masao
• Granted Patent: US 9,516,699 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
• CPC Class Codes: G08C 15/06 successively, i.e. using time division
• CPC Class Codes: H04M 11/00 Telephonic communication systems specially adapted for combination with other electrical systems
• CPC Class Codes: H04Q 2209/10 using a centralized architecture
• CPC Class Codes: H04Q 2209/40 using a wireless architecture
• CPC Class Codes: H04Q 2209/82 where the sensing device takes the initiative of sending data
• CPC Class Codes: H04Q 2209/823 where the data is sent when the measured values exceed a threshold, e.g. sending an alarm
• CPC Class Codes: H04Q 2209/88 Providing power supply at the sub-station
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
• CPC Class Codes: H04W 52/0251 using monitoring of local events, e.g. events related to user activity
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/18 Service support devices; Network management devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A sensor network system is provided with a plurality of sensor terminals disposed in a predetermined area, and a monitoring center device that collects sensing data wirelessly transmitted from each of the plurality of sensor terminals. The sensor terminals wirelessly and intermittently transmit a transmission signal including sensor identification information and the latest sensing data from the sensors. The monitoring center device has the function of acquiring positional information of the sensor terminals in the predetermined area, and accumulates each item of the sensing data from the sensor terminals as time-series data in association with information about the time of acquisition. On the basis of the positional information of the sensor terminals and the time-series data of the accumulated sensing data, a time-series variation of an environmental element in the predetermined area is visually presented. The sensor network system enables the monitoring of detailed environmental changes corresponding to differences in position in a monitored area.

Claims

1. A sensor network system comprising:

a plurality of sensor terminals which are driven with a stand-alone power supply and provided in a predetermined area in which one or more sensors are connected to each of the sensor terminals provided at a predetermined position in the predetermined area to wirelessly transmit a sensing data sensed with the sensor; and

a monitoring center device collecting the sensing data wirelessly transmitted from the sensor terminals,

the sensor terminal having a wireless transmission means for wirelessly transmitting intermittently a terminal identification information identifying each sensor terminal, a sensor identification information identifying each type of the sensor and a latest sensing data of each sensor,

the monitoring center device comprising;

a positional information acquisition means for acquiring a positional information of the sensor terminals in the predetermined area;

a sensing data accumulation means for accumulating a time-series data of each sensing data sent from the sensor terminals as corresponding to an acquisition time of the sensing data; and

a visualization means for presenting a visualized time-series variation of an environmental element detected by the sensor in the predetermined area by using the positional information of the sensor terminal acquired by the positional information acquisition means and the time-series data of the sensing data accumulated by the sensing data accumulation means.

2. The sensor network system according to claim 1, wherein the monitoring center device regards a receiving time of a signal including the sensing data as the acquisition time of the sensing data to accumulate the sensing data and the transmission signal does not include the acquisition time of the sensing data.

3. The sensor network system according to claim 1, wherein the transmission signal does not include any synchronization information and the transmission signal is constantly monitored to detect a receiving at a receiving side.

4. The sensor network system according to claim 1, wherein at least three relay devices are provided in the predetermined area, each of the relay devices comprises:

a radio field intensity detection means for detecting a radio field intensity of a receiving time of the transmission signal; and

a transfer means for transferring an information of the radio field intensity together with the terminal identification information, the sensor identification information and the sensing data sensed with the sensor to the monitoring center device,

the positional information acquisition means acquiring an estimated position of the sensor terminal identified by the terminal identification information from the information of the radio field intensity included in signals which include the same terminal identification information, the same sensor identification information and the same sensing data among the transferred signals transferred from said at least three relay devices.

5. The sensor network system according to claim 4, wherein each of the relay devices has a receiving time detection means for detecting the receiving time of the transmission signal,

the transfer means transferring an information of the receiving time together with the terminal identification information, the sensor identification information, the sensing data sensed with the sensor and the information of the radio field intensity to the monitoring center device,

the monitoring center device regarding the receiving time as the acquisition time of the sensing data to accumulate the sensing data.

6. The sensor network system according to claim 1, wherein at least three relay devices are provided in the predetermined area, each of the relay devices comprising:

a receiving time detection means for detecting a receiving time of the transmission signal; and

a transfer means for transferring the information of the receiving time together with the terminal identification information, sensor identification information and the sensing data sensed with the sensor to the monitoring center device,

the monitoring center device regarding the receiving time as the acquisition time of the sensing data to accumulate the sensing data,

the monitoring center device acquiring an estimated position of the sensor terminal identified by the terminal identification information according to a time difference between the receiving times included in signals which include the same terminal identification information, the same sensor identification information and the same sensing data among the transferred signals transferred from said at least three relay devices.

7. The sensor network system according to claim 1, wherein each of the sensor terminals has a randomizer, which generates a random value employed to decide a starting time of the intermittent wireless transmission.

8. The sensor network system according to claim 1, wherein each of the sensor terminals detects a predetermined event according to the sensing data sensed with any one of the sensors, and wirelessly transmits the transmission signal when the event occurs, regardless of a timing of the intermittent wireless transmission.

9. The sensor network system according to claim 1, wherein each of the sensor terminals detects a predetermined event according to the sensing data sensed with any one of the sensors, changes a cycle of the intermittent wireless transmission and wirelessly transmits the transmission signal when the event occurs.

10. The sensor network system according to claim 1, wherein each of the sensor terminals wirelessly transmits the same transmission signal in a first frequency band and a second frequency band per each wireless transmission.

11. The sensor network system according to claim 10, wherein the sensor terminal wirelessly transmits the same transmission signal in the first frequency band of a time interval and the second frequency band of another time interval.

12. The sensor network system according to claim 10, wherein the sensor terminal wirelessly transmits the same transmission signal simultaneously in the first frequency band and the second frequency band.

13. The sensor network system according to claim 1, wherein each of the sensor terminals has a modulation means for modulating a transmission data by a modulation method to allocate different the wireless transmission frequencies to different transmission data.

14. The sensor network system according to claim 13, wherein the modulation means decides a spread code according to the transmission data and decides the wireless transmission frequency allocated to a chip code value of the spread code.