OBJECT STATE DETECTION APPARATUS AND METHOD

• US 20100019759A1
• Filed: 04/28/2009
• Published: 01/28/2010
• Est. Priority Date: 04/30/2008
• Status: Active Grant

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Hirota, Kiyomi, Kaji, Ryosaku, Shimizu, Mitsuaki
• Granted Patent: US 8,508,219 B2
• Time in Patent Office: Days
• US Class Current: 324/144
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00

Abstract

There is provided an apparatus and method for identifying and measuring the electric field strength which occurs from each of RFID tags arranged in a detection target space by a receiver to grasp the state of an object. The apparatus is provided with m (m>=1) electromagnetic field generation means provided near a space, the space being occupied by the object when the object is in a particular state; n (n>=1) electric field strength measurement means for identifying and measuring electric field strength which occurs from each of the m electromagnetic field generation means; characteristic extraction means for calculating characteristics from m×n time-series data of the electric field strength; and state identification means for identifying, by statistical processing, a state from the characteristics and characteristic data in each state for learning.

Claims

1. An apparatus for detecting a state of an object, comprising:

m (m>

=1) electromagnetic field generation means provided near a space, the space being occupied by the object when the object is in a particular state;

n (n>

=1) electric field strength measurement means for identifying and measuring electric field strength which occurs from each of the m electromagnetic field generation means;

characteristic extraction means for calculating characteristics from m×

n time-series data of the electric field strength; and

state identification means for identifying, by statistical processing, the state from the characteristics and characteristic data in each state for learning.

2. The object state detection apparatus according to claim 1, wherein each of the electromagnetic field generation means has an antenna structure for controlling spatial distribution of accumulated fields.

3. The object state detection apparatus according to claim 1, wherein an efficiency of radiation of an electromagnetic field into free space by the electromagnetic field generation means changes when an object exists nearby.

4. The object state detection apparatus according to claim 1, wherein the n electric field strength measurement means are arranged so that the states of the electromagnetic fields which occur from the electromagnetic field generation means changing due to existence of the object can be measured separately from one another.

5. The object state detection apparatus according to claim 1, wherein the characteristic extraction means converts m×

n electric field strength values at the time when the space is in a still state into vector data with m×

n elements.

6. The object state detection apparatus according to claim 1, wherein the state identification means learns a upper-limit value and a lower-limit value of the electric field strength for each of the m×

n data, from the characteristic data of each still state which has been collected for learning, and identifies the state by the fact that input character data is between the upper-limit value and the lower-limit value of the electric field strength.

7. The object state detection apparatus according to claim 1, wherein the apparatus executes alarm processing in accordance with the state identification by the state identification means.

8. The object state detection apparatus according to claim 1, wherein the apparatus performs processing of photographing data of the space in accordance with the state identification by the state identification means.

9. A method for detecting a state of an object, wherein

providing m (m>

=1) transmitters near a space, the space being occupied by the object when the object is in a particular state;

identifying and measuring electric field strength which occurs from each of the m transmitters by n (n>

=1) receivers;

calculating characteristics from m×

n time-series data of the electric field strength; and

identifying, by statistical processing, the state is identified from the characteristics and characteristic data in each state for learning.

10. The object state detection method according to claim 9, wherein each of the transmitters has an antenna structure for controlling spatial distribution of accumulated fields.

11. The object state detection method according to claim 9, wherein an efficiency of radiation of an electromagnetic field into free space by each of the transmitters changes when the object exists nearby.

12. The object state detection method according to claim 9, wherein the n receivers are arranged so that the states of electromagnetic fields which occur from the transmitters changing due to existence of the object can be measured separately from one another.

13. The object state detection method according to claim 9, wherein the characteristic calculation processing converts m×

n electric field strength values at the time when the space is in a still state into vector data with m×

n elements.

14. The object state detection method according to claim 9, wherein the state identification processing learns a upper-limit value and a lower-limit value of the electric field strength for each of the m×

n data from characteristic data of each still state which has been collected for learning, and identifies the state by the fact that input character data is between the upper-limit value and the lower-limit value of the electric field strength.

15. The object state detection method according to claim 9, wherein alarm processing is executed in accordance with the state identification.

16. The object state detection method according to claim 9, wherein processing of photographing data of the space is performed in accordance with the state identification.