JP2012098886A - Automatic monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily provide an automatic monitoring system in a three-dimensional space added with location information in a depth direction to the conventional automatic monitoring systems.SOLUTION: In an automatic monitoring system, when a detection object is detected in a set monitoring area 10-2 by using a monitoring camera and a distance measuring function, a distance from the monitoring camera to the detection object is measured, and only when the distance falls in a predetermined range, it is determined that "an intruder exists." Thus, it is made possible to easily provide the automatic monitoring system in a three-dimensional space added with information in a depth direction while keeping a method to set the monitoring area on a screen of a picked-up image unchanged.

Description

The present invention relates to an automatic monitoring system using a monitoring camera, and more particularly, in an automatic monitoring system that sets a monitoring area on a screen, adds information in the depth direction to the monitoring camera for more accurate automatic monitoring.

An automatic surveillance system using a surveillance camera compares at least two images after a predetermined time to determine whether the detection target is moving. If it is stationary, it is a landscape. If it is moving, it is an intruder. Distinguish from being.

There are two types of monitoring areas: the method of monitoring everything that falls within the field of view and the method of setting a monitoring area and monitoring only within this area, but from the viewpoint of malfunction, responsiveness, simplicity, and system scale, the monitoring area It is more appropriate to specify this and monitor only within this area.

Regarding the setting of the monitoring area, a method using a two-dimensional plane (Patent Document 1) or a one-dimensional line segment (Patent Document 2) has been proposed. Each method has been devised in practice, such as the ability to set multiple monitoring areas on the screen, but because there is no depth information in the monitoring area, it can be used for movements such as passages and entrances. Limited to physically limited spaces.

JP 2006-165666 A JP 2009-225239 A

In a conventional automatic monitoring system, when a monitoring area is set on the screen of the captured image, only two-dimensional information can be acquired when shooting with one monitoring camera (one dimension when the monitoring area is set as a line). For example, when the surveillance camera is set approximately horizontally, the range that overlaps the surveillance area when viewed from the surveillance camera is the area to be monitored from the point immediately before the surveillance camera to the far distance. Has a problem of monitoring different spaces.

2 and 3 again, the surveillance camera 1 is trying to monitor the surveillance area 10-1 in the entire visual field, but a person is on the straight line between the surveillance camera 1 and the surveillance area 10-1. As shown in FIG. 3, even if a person is in front of the monitoring area 10-2 (4-1) or a person is behind the monitoring area 10-1 (4-2) In addition, the surveillance camera 1 appears as if it has entered the surveillance area 10-1, and has a disadvantage of giving false information.

For this reason, the conventional automatic monitoring system is effective under conditions where the flow of people is almost constant, such as monitoring intruders in hallways and entrances, but for example, around the monitored object placed in the center of a large hall There are also usage restrictions such as monitoring intruders that are not suitable for monitoring three-dimensional spaces where human traffic is not uniform.

Measures against these inconveniences include monitoring from directly above the monitoring area, calculating three-dimensional information from information from multiple monitoring cameras in different directions, or installing pressure sensors on the floor. Although it is conceivable, for example, when there are a plurality of monitoring areas, the system becomes complicated by any method.

In addition, this inconvenience can be alleviated by simply monitoring from diagonally above, but this is not a complete solution, and further, the installation location and field of view of the surveillance camera 1 are limited, and the field of view to be originally monitored cannot be obtained. There may be cases.

In view of these circumstances, the present invention provides an automatic monitoring system in a three-dimensional space in which information in the depth direction is simply added without changing the method of setting a monitoring area on the screen of a captured image.

In the automatic monitoring system, when a detection target is detected in the set monitoring area (that is, a moving object is shown in the monitoring area), the distance from the monitoring camera to the detection target is measured using the distance measuring method described below. Only when this distance is within a preset range, it is determined that “there is an intruder”.

The distance measuring method may be a distance measuring device using reflection of laser or ultrasonic waves, and the reflected light from the detection target is received by the camera and the intensity is measured (the reflected light is strong when close, and the reflected light becomes weak as moving away) It is also possible to use a focusing function provided by the surveillance camera itself.

By configuring as described above, it is possible to easily add information in the depth direction by using the single monitoring camera without changing the method of setting the monitoring area on the screen of the captured image. It is possible to provide an automatic monitoring system in a three-dimensional space with high reliability in view.

FIG. 6 is a conceptual diagram of distance measurement in the depth direction according to the first and fourth embodiments of the present invention. Explanatory drawing (bird view) of the malfunction in the conventional monitoring system. Explanatory drawing (photographed image) of the malfunction in the conventional monitoring system.

(First embodiment)

A first embodiment will be described with reference to FIG.

The monitoring camera 1 is generally horizontal and monitors a preset monitoring area 10-1.

In the vicinity of the monitoring camera 1, a distance measuring device 2 facing the direction of the monitoring area 10-1 is disposed. The distance measuring principle of the distance measuring device 2 may be laser light reflection or ultrasonic wave reflection.

The processing unit 3 controls the monitoring camera 1 and the distance measuring device 2, processes information sent from them, and supervises the entire automatic monitoring system. Generally, it is convenient to use a personal computer. It is.

For the entire automatic monitoring system, known techniques in the field of the automatic monitoring system can be applied mutatis mutandis, except that the distance measuring device 2 is driven and the data obtained thereby is taken into consideration.

When the monitoring camera 1 detects the detection target 4 in the monitoring area 10-1, the distance measuring device 2 measures the distance Ya to the detection target 4, and this Ya is set in advance to Y1, Y2 When Y1 ≦ Ya ≦ Y2 holds, it is determined that “there is an intruder” and an alarm is issued. In other words, it is possible to monitor the three-dimensional space of X × Z × (Y2-Y1) in FIG.

By configuring as described above, it is possible to easily add information in the depth direction by using a single monitoring camera, without changing the method of setting the monitoring area on the screen of the photographed image 5. It is possible to provide an automatic monitoring system in a three-dimensional space with a high reliability in an installation place and an arbitrary field of view.

In the above description, the monitoring area 10-1 is a two-dimensional plane as an example. However, this may be a one-dimensional line segment or a point where the area is made extremely small.

Further, although an example in which only one monitoring area 10-2 is set has been described, a plurality of monitoring areas 10-2 may be provided. At this time, whether to install a plurality of distance measuring devices 2 or whether to direct one distance measuring device 2 to the monitoring area 10-2 where the reaction occurred using an automatic movable table, or one distance measuring device 2 Whether or not the distance measurement range may be fixed (for example, when there are very few people going in and out), a method more suitable for the situation is adopted.

(Second embodiment)

In the first embodiment, the distance measuring device 2 utilizing laser light or ultrasonic waves is given as a specific example of the distance measuring method, but as the distance measuring method, the intensity of reflection of the detection target 4 is measured by the monitoring camera 1. Then, the distance Ya may be grasped. Specifically, when the detection target 4 is detected in the monitoring area 10-1, the actual use environment in which the intensity of the reflected light of that portion (the luminance of the part on the captured image 5) is obtained in advance. It is possible to determine whether or not the detection target 4 in the monitoring area 10-2 is an intruder by comparing the intensity of reflected light from the Y1 position and Y2 position to the monitoring camera 1.

(Third embodiment)

Further, as a distance measuring method, the focusing function of the monitoring camera 1 may be utilized. Specifically, when the detection target 4 is detected in the monitoring area 10-1, the distance Ya to the detection target 4 is measured using the focusing function of the monitoring camera 1, and the detection in the monitoring area 10-2 is performed. It can be determined whether the subject 4 is an intruder. .

The distance measurement methods of the second and third embodiments are inferior in distance measurement accuracy as compared to the first embodiment, but for example, it is desired to eliminate the influence of ambient light on the window glass in front of the surveillance camera 1 There are many situations where strict distance measurement accuracy is not required, and there is an advantage that a required function can be realized with a simple configuration because the distance measurement device 2 is not used.

(Fourth embodiment)

As described above, from the first embodiment to the third embodiment, the monitoring of the intruder into the monitoring area 10-2 has been described. However, in the configuration including the distance measuring device 2 in the present invention, the intruder It can also be used for countermeasures against the act of obstructing the automatic monitoring by covering the visual field of the surveillance camera 1 with a cover or the like.

When the image is darkened at a predetermined rate (for example, 80%) of the captured image 5 for a predetermined time (for example, 2 seconds), the distance measuring device 2 determines whether there is an object near Y0 (FIG. 1). ) Whether the lighting in the room has been turned off (no response to the distance measuring device 2), or whether a person or an object has just passed in front of the surveillance camera 1 (the response of the distance measuring device 2 has changed from “Yes” to “ It is possible to determine whether the cover has actually been covered (there is a person or an object in the vicinity of the surveillance camera 1), and countermeasures against false alarms can be taken.

In addition, in determining darkness, the brightness of the entire captured image 5 may be reduced (measures for a translucent shield), or may be used in combination with a method using the above area as a parameter.

1: Surveillance camera

2: Distance measuring device

3: Processing section

4-1: Person (before the monitoring area)

4-2: Person (behind monitoring area)

5: Captured image (monitor frame)

10-1: Monitoring area (2D plane)

10-2: Monitoring area (3D space)

Claims (6)

An automatic monitoring system with a surveillance camera,

When a detection target is detected in the monitoring area set for the monitoring camera, the distance from the monitoring camera to the detection target is measured, and the detection target enters only when this distance is within a preset range. An automatic monitoring system characterized in that it is determined that the person is a person and reports.

In claim 1 above,

An automatic monitoring system, wherein the distance measuring method is a method using a distance measuring device utilizing reflection of laser light.

In claim 1 above,

An automatic monitoring system, wherein the distance measuring method is a method using a distance measuring device utilizing reflection of ultrasonic waves.

In claim 1 above,

An automatic monitoring system characterized in that the distance measuring method grasps the distance between the camera and the detection target by measuring the intensity of reflected light from the detection target incident on the camera.

In claim 1 above,

An automatic monitoring system characterized in that the distance measuring method is a method utilizing the automatic focusing function of the camera itself.

An automatic monitoring system with a surveillance camera,

A distance measuring device is installed in the vicinity of the monitoring camera, the field of view of the monitoring camera is closed, and when the reflection from the distance closer than a predetermined distance is detected by the distance measuring device, automatic monitoring is obstructed. Automatic monitoring system characterized by judging and reporting.

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