Wireless communication device and wireless communication system that performs wireless communication with a counterpart device using a directional antenna

• US 9,973,947 B2
• Filed: 11/28/2016
• Issued: 05/15/2018
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Original Assignee: Hitachi Kokusai Electric Incorporated (Hitachi, Ltd.)
• Inventors: Iwanaga, Kazunari, Kobayashi, Shinya, Sasanami, Naoyasu
• Primary Examiner(s): Pezzlo, John
• Application Number:
  US15/362,235
• Publication Number:
  US 20170078901A1
• Time in Patent Office: 533 Days
• Field of Search: 370241, 370329, 370386
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/277 involving stochastic approaches, e.g. using Kalman filters
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

A wireless device includes an imaging unit having an optical axis which is identical to a radio wave direction of a directional antenna, a reference image is stored in a storage unit, a wireless communication device serving as a communication counterpart and an area around the wireless communication device are photographed at regular intervals, and a control unit compares images photographed at regular intervals with a reference image, calculates a degree of similarity through normalized cross-correlation which is hardly influenced by a change in brightness, calculates an index value indicating a state of a region serving as a monitoring target based on a degree of weighted similarity, detects an abnormality when the index value is a specific numerical value or less, and outputs alert information including the photographed image when a state in which the abnormality is detected is continued for a certain period of time.

Claims

1. A wireless communication device that performs wireless communication with a counterpart device using a directional antenna, comprising:

an imaging unit that has an optical axis which is identical to a radio wave direction of the directional antenna, and photographs images of regions corresponding to the counterpart device serving as a monitoring target;

a storage unit that stores a reference image serving as a reference which is photographed by the imaging unit; and

a control unit that performs a communication failure prediction process of acquiring a photographed image photographed by the imaging unit at regular intervals, calculating a degree of similarity between the photographed image and the reference image for each of the regions serving as the monitoring target through normalized cross-correlation, calculating an index value representing a state of the regions serving as the monitoring target based on degrees of similarity which is weighted, detecting an abnormality when the index value is a specific numerical value or less, and outputting alert information including the photographed image when a state in which the abnormality is detected is continued for a certain period of time;

wherein the control unit sets a monitoring region including the counterpart device and a plurality of divisional blocks obtained by dividing an extended region obtained by extending the monitoring region as the region serving as the monitoring target, and in the communication failure prediction process, the control units calculates the degree of similarity between the photographed image and the reference image for the monitoring region and the plurality of divisional blocks, calculates an integrated index value in which the degrees of similarity of the monitoring region and the plurality of divisional blocks are integrated as the index value indicating the state of the region serving as the monitoring target, and detects the abnormality when the integrated index value is a threshold value which is set in advance or less.

2. The wireless communication device according to claim 1,

wherein in the communication failure prediction process, the control unit weights the degree of similarity of each of the plurality of divisional blocks according to a degree of importance of each of the plurality of divisional blocks, and calculates the integrated index value based on the degree of similarity which is weighted.

3. The wireless communication device according to claim 1,

wherein the storage unit stores the photographed image, and stores the degrees of similarity of the plurality of divisional blocks for a specific period of time for each photographed image, and

when the abnormality is detected in the communication failure prediction process, the control unit estimates a cause of the abnormality based on the degrees of similarity of the plurality of divisional blocks for the specific period of time until now, includes information indicating the estimated cause in alert information, and outputs the alert information.

4. The wireless communication device according to claim 2,

wherein the storage unit stores the photographed image, and stores the degrees of similarity of the plurality of divisional blocks for a specific period of time for each photographed image, and

when the abnormality is detected in the communication failure prediction process, the control unit estimates a cause of the abnormality based on the degrees of similarity of the plurality of divisional blocks for the specific period of time until now, includes information indicating the estimated cause in alert information, and outputs the alert information.

5. A wireless communication system, comprising:

a pair of wireless communication devices which are installed to face each other,

wherein each of the wireless communication devices performs wireless communication with a counterpart device using a directional antenna, comprising

an imaging unit that has an optical axis which is identical to a radio wave direction of the directional antenna, and photographs images of regions corresponding to the counterpart device serving as a monitoring target;

a storage unit that stores a reference image serving as a reference which is photographed by the imaging unit; and

a control unit that performs a communication failure prediction process of acquiring a photographed image photographed by the imaging unit at regular intervals, calculating a degree of similarity between the photographed image and the reference image for each of the regions serving as the monitoring target through normalized cross-correlation, calculating an index value representing a state of the regions serving as the monitoring target based on degrees of similarity which is weighted, detecting an abnormality when the index value is a specific numerical value or less, and outputting alert information including the photographed image when a state in which the abnormality is detected is continued for a certain period of time;

wherein the control unit sets a monitoring region including the counterpart device and a plurality of divisional blocks obtained by dividing an extended region obtained by extending the monitoring region as the region serving as the monitoring target, and in the communication failure prediction process, the control units calculates the degree of similarity between the photographed image and the reference image for the monitoring region and the plurality of divisional blocks, calculates an integrated index value in which the degrees of similarity of the monitoring region and the plurality of divisional blocks are integrated as the index value indicating the state of the region serving as the monitoring target, and detects the abnormality when the integrated index value is a threshold value which is set in advance or less.

6. The wireless communication system according to claim 5,

wherein, when the abnormality is detected in the communication failure prediction process, the control unit of the wireless communication device acquires a processing result of the communication failure prediction process in the counterpart device, adds a processing result in the wireless communication device to the processing result in the counterpart device, and estimates the cause of abnormality.