Proximate sensor using micro impulse waves for monitoring the status of an object, and monitoring system employing the same

• US 20030160701A1
• Filed: 08/27/2002
• Published: 08/28/2003
• Est. Priority Date: 02/25/2002
• Status: Active Grant

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Nakamura, Akihiko, Hisano, Atsushi
• Granted Patent: US 6,954,145 B2
• Time in Patent Office: Days
• US Class Current: 340/686.6
• CPC Class Codes: G08B 13/181 using active radiation detection systems
• CPC Class Codes: G08B 13/24 by interference with electromagnetic field distribution
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: G08B 13/2491 Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range

Abstract

The objective of the present invention is to provide proximity sensors employing impulse waves to detect the characteristics of objects lying inside the object of surveillance, such as a container, including their distance, the reflection strength from an object, the speed an object is moving, etc., as well as to provide a status surveillance system which detects, from the data from the proximity sensors, that the inside of the container remains unchanged. To achieve the foregoing objectives, the present invention adds proximity sensor functions to wireless communication nodes inside of the object of surveillance, such as inside of a container. Said proximity sensors output microimpulse waves from the wireless communication nodes, and said communication nodes receive the reflections of those waves from nearby objects. The wave reception sampling is performed based upon the bit signals of the clock for the microimpulse transmissions and the local clock, and the analysis of the received signals enables the highly precise measurement of the distance to an object using simple circuitry. It is then possible to detect an abnormal occurrence inside the object of surveillance by comparing the characteristic data obtained from the initial environment with that data obtained during the period of surveillance. Further, the proximity sensing function is able to detect the direction of any penetration.

Claims

1. A proximity sensor provided in each wireless communication node which is installed inside of the object of surveillance for surveying the inside status of said object of surveillance, comprising:

an output means to output microimpulse waves from the wireless communication node toward the three dimensional directions inside of said object of surveillance;

a receiving means to receive the reflected waves of said output microimpulse waves which are reflected on the articles loaded inside of said object of surveillance; and

a detecting means to detect a characteristic data in said received reflected waves received by said receiving means for surveying the inside status of said object of surveillance.

2. A proximity sensor according to claim 1, wherein said characteristic data is defined by either a distance between said proximity sensor and said articles which cause said reflection, a reflection strength of said received reflected wave, or a moving speed of said article.

3. A proximity sensor according to claim 1, wherein said received reflected waves are a plurality of reflected waves including a first reflected wave from said article.

4. A proximity sensor according to claim 1, wherein said characteristic data is detected by the modulated waveform which is obtained by modulating said received reflected waves with the locally oscillated waves.

5. A proximity sensor provided in each wireless communication node which is installed inside of the object of surveillance, said proximity sensor detecting a direction of unauthorized penetration in which an unauthorized article penetrates a wall of said object of surveillance, comprising:

an output means to output two layered microimpulse waves from the wireless communication node toward the two dimensional directions parallel to the wall of said object of surveillance, and said;

a receiving means to receive two reflected waves of said two layered microimpulse waves, which are reflected on said unauthorized article penetrating said wall of said object of surveillance; and

a detecting means to detect a characteristic data in said two received reflected waves of said two layered microimpulse waves for detecting said direction of unauthorized penetration.

6. A proximity sensor according to claim 5, wherein said characteristic data is detected by the receiving time lag between said two received reflected waves of said two layered microimpulse waves.

7. A proximity sensor according to claim 5, wherein said output means outputs a plurality of layered microimpulse waves from the wireless communication node, each layered microimpulse wave being output through each slot provided in said wireless communication node, and said receiving means receives a plurality of reflected waves of said plurality of layered microimpulse waves.

8. A status surveillance system to monitor the status of an object of surveillance using microimpulse waves, comprising:

a first detecting means to detect a plurality of mutual distances between a plurality of communication nodes by outputting microimpulse waves toward[s] the three dimensional directions inside of said object of surveillance, and obtain a network structure information of said object by said plurality of detected mutual distances; and

a second detection means to detect a characteristic data in a plurality of reflected waves which are reflected on the articles loaded inside of said object of surveillance;

wherein said status surveillance system monitors said status of said object of surveillance by said network structure information and said characteristic data.

9. A status surveillance system according to claim 8;

wherein said network structure information is obtained by said plurality of detected mutual distances which are detected by the responding time lags of the responding microimpulse waves which are responses from other communication nodes, and

said characteristic data is obtained by either a distance between said plurality of communication nodes and said articles which cause said reflection, a reflection strength of said received reflected wave, or a moving speed of said article.

10. A status surveillance system, according to claim 8, wherein said system records an initial data which is obtained from an initial characteristic data and network structure information obtained by said reflected waves in an initial environment, and compares said initial data with said characteristic data and said network structure information in a surveillance period, for monitoring said status of said object of surveillance.

11. A status surveillance system, according to claim 8, wherein said object of surveillance is a freight container that is transported by aircraft or ship.

12. A status surveying method to survey the inside status of an object of surveillance, comprising the steps of:

outputting microimpulse waves from the wireless communication node towards the three dimensional directions inside of said object of surveillance;

receiving the reflected waves of said output microimpulse waves which are reflected on the articles loaded inside of said object of surveillance; and

detecting a characteristic data in said received reflected waves received by said receiving means for surveying the inside status of said object of surveillance.

13. A status surveying method to survey the inside status of an object of surveillance, comprising the steps of:

detecting a plurality of mutual distances between a plurality of communication nodes by outputting microimpulse waves towards the three dimensional directions inside of said object of surveillance, and obtain a network structure information of said object by said plurality of detected mutual distances;

detecting a characteristic data in a plurality of reflected waves which are reflected on the articles loaded inside of said object of surveillance; and

monitoring said status of said object of surveillance by said network structure information and said characteristic data.