JPH1079934A - Method and apparatus for monitoring entry into a monitored area - Google Patents

Abstract

(57) [Summary] [Object] To provide a method and apparatus capable of quickly and reliably monitoring three-dimensional spatial coordinates of a monitoring target and a moving object by a simple method and at a low cost. And A surveillance map creating means for preliminarily calculating left and right image coordinates corresponding to a surveillance area 35 centering on a surveillance object 34 by a stereo method using a plurality of TV cameras, creating and storing a surveillance map, This is a method for monitoring intrusion into a monitoring area, which comprises monitoring means for searching the monitoring map from the coordinates of the moving object 37 obtained by image processing at the time of monitoring and determining the state of an alarm. According to this method,
When the alarm state is determined, the alarm can be determined without calculating the distance between the moving object 37 such as a crane and the monitoring target 34 such as a transmission line every time, and the processing time can be reduced.
The purpose can be achieved by a simple device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides an alarm when a person enters a substation or a moving object such as a crane approaches a power transmission line, and provides protection for human beings as well as substations and power transmission lines. The present invention relates to a method and an apparatus for monitoring intrusion into a monitoring area for the purpose of preventing failure.

[0002]

2. Description of the Related Art For example, as shown in FIG. 10, when a moving object 37 such as a crane is operated near an object 34 to be monitored such as a power transmission line, an accident such as a personal injury due to a contact, a power failure or other failure occurs. Are increasing year by year. Therefore, as shown in FIG. 11, it is necessary to assume a monitoring area 35 around the monitoring target 34, and to notify by a warning when the moving object 37 approaches the monitoring area 35. As a measure to prevent contact when an approaching object approaches a transmission line as a dangerous object, the monthly magazine “O
According to HM, December 1991, pages 44 to 49, the following problems are pointed out as conventional monitoring methods, and the following methods are described as methods for solving them.

[0003] A method of laying a protective rope or fence around the monitoring area 35. This method not only takes time to install the ropes and fences, but also unnecessarily increases the space for installing the ropes and fences. Nevertheless, sufficient protection cannot be provided, and when the monitored area 35 is a substation or power transmission line, power transmission must be temporarily stopped, making it difficult to secure power outages. Was.

[0004] A witness safety monitoring method. Since the witness monitors visually, the error is large especially when the distance is long, and the monitoring is often performed for a long time, so that the attention is easily distracted. The monitoring effect is improved by using the above method in combination. However, in the case of a sky such as a power transmission line, even if a rope or a fence is stretched over the ground, the effect is not necessarily perfect.

[0005] A planar image processing monitoring method using one TV camera. In this method, a human must constantly monitor the monitor screen, and since it is a flat image, it cannot cope with approaching in the depth direction. There is.

[0006]

A method of measuring the three-dimensional spatial coordinates of a dangerous object and a moving object with a plurality of TV cameras every moment, and issuing an alarm when approaching the dangerous area. There is also a method of automatically measuring three-dimensional coordinates with two TV cameras, but there is a problem that a calculation for measuring the three-dimensional spatial coordinates every moment is complicated and a large-sized device is required. . Therefore, as described above, a method has been proposed in which measurement is performed by a simple device using a plurality of TV cameras, specifically, five TV cameras.

[0007] The method using a plurality of TV cameras can substantially eliminate the above-mentioned disadvantages, but can reduce the number of TV cameras.
The three-dimensional spatial coordinates of the dangerous object and the moving object must be continuously measured from time to time with a V camera, and the degree of risk must be calculated from the distance based on the changing spatial coordinates of the two. No. Therefore, two TVs
It is more accurate than automatically measuring three-dimensional coordinates with a camera,
Although the processing process is simple, there is a problem that the measurement process is still complicated and a large device is required.

According to the present invention, a simple method and an inexpensive device can be used to quickly measure the three-dimensional spatial coordinates of a monitoring target and a moving object without the need to continuously measure each moment. It is an object of the present invention to provide a method and an apparatus capable of reliably monitoring.

[0009]

The basic principle of the present invention is as follows.
By the stereo method using two TV cameras, the left and right image coordinates corresponding to the monitoring area 35 are calculated in advance, saved as a file, and a file is searched from the coordinates of the corresponding points obtained by image processing during monitoring, and an alarm is issued. This is a method of trying to determine the state of. That is, a monitoring map creating means for previously calculating left and right image coordinates corresponding to a monitoring area 35 around a monitoring target object 34 by using a stereo method using a plurality of TV cameras to create and store a monitoring map, This is a method for monitoring intrusion into a monitoring area, which comprises monitoring means for searching the monitoring map from the coordinates of the moving object 37 sometimes obtained by image processing and determining the state of an alarm.

By adopting such a method, the alarm can be determined without determining the distance between the moving object 37 such as a crane and the monitored object 34 such as a transmission line every time when the alarm state is determined. In addition to shortening the time, the object can be achieved with a simple device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 3, the device according to the present invention comprises a visual device 11, a measurement processing device 12, and an alarm device 13. The visual device 11 includes two TV cameras 14 and 15 composed of CCD cameras arranged at regular intervals. The measurement processing device 12 is provided with the T
A / D converters 16 and 17 coupled to the output sides of the V cameras 14 and 15, an image measurement processing unit 18 that measures and processes the captured image, controls each circuit, and the like. A ROM 19, a RAM 20, a moving object coordinate extracting unit 21 for extracting coordinates of a moving object 37, a monitoring map processing unit 22 for processing a monitoring map of a monitoring area 35,
An intrusion determination unit 23 that determines whether the vehicle is in a dangerous area is provided. The alarm device 13 includes an alarm transmitting unit 24 that outputs an alarm signal, and an alarm output unit 25 that issues an alarm using light, sound, or the like.

Next, a monitoring method will be described with reference to the drawings.
The principle of the monitoring method is that, as shown in the flowchart of FIG. 1, the monitoring map creating means sets a three-dimensional area centered on the monitoring target object as a monitoring area, and the left and right image coordinates of the TV cameras 14 and 15 corresponding thereto. Is calculated in advance, a monitoring map is created and stored in a file. In the monitoring means,
The monitoring map is searched from the coordinates of the moving object 37 obtained by the image processing at the time of monitoring, and the state of the alarm is determined. This will be described in more detail.

1. Means for creating a monitoring map (flow chart shown in FIG. 2) (1) Image input (means a) As shown in FIG. 4, two TV cameras 1 installed in parallel
At 4 and 15, the monitoring object 34 is displayed on the left screen 32 and the right screen 33.
An image is input so as to include the monitoring area 35 in the field of view. Reference numeral 30 denotes a left objective lens position of the TV camera 14, and reference numeral 31 denotes a right objective lens position of the TV camera 15.

(2) Setting of Monitoring Object 34 (Means b) As shown in FIG. 4, an alarm distance R is set centering on the monitoring object 34, and a three-dimensional space is defined as a monitoring area 35.

(3) Calculation of the monitoring area 36 on the left screen 32 (means c) As shown in FIG. 5, based on the alarm distance R of the actual monitoring area 35, the left of the warning distance r on the left screen 32 is calculated. The on-screen monitoring area 36 is calculated.

(4) Saving the coordinate values of the monitoring area 36 on the left screen 32 in a file (means d) As shown in FIG. 6, numbers corresponding to each image array in the monitoring area 36 on the left screen are assigned. , Save to a file. For example, the left coordinates (XLn,
YLn) is the n-th number, and the number n is registered in the file. Similarly, the numbers of the left screen coordinates of all the points in the monitoring area 36 on the left screen corresponding to the monitoring area 35 of the monitoring target 34 are registered to form a corresponding point table. 1
A plurality of regions of corresponding points are put in the pixel.

(5) Calculation of the monitoring area 39 on the right screen 33 (means e) The right screen monitoring area 39 on the right screen 33 corresponding to the n-th point on the left screen 32 is calculated. More specifically, x,
As shown in the three-dimensional diagram of y and z, the n-th
The point (XLn, YLn) is the image point O of the optical axis of the TV camera 14.
1 and a straight line passing through P1 and P2 on the outer surface of the monitoring area 35 (a sphere having a radius warning distance R). I do. 35
a is a cutting horizontal plane including P1 and P2. Next, TV
An image of the monitoring area 35 is displayed on the right screen 33 of the camera 15, and points on a straight line connecting the P1 and P2 with the image point O2 of the optical axis of the TV camera 15 are defined as Q1 and Q2, respectively. The space between the straight lines connecting (X3, Y3) and (X4, Y4) is filed as the monitoring area 39 on the right screen. FIG. 8A shows FIG. 7 in a two-dimensional plan view of x and y, and FIG.
In a two-dimensional plan view of z and x.

Next, the calculation formula will be described. The principle of triangulation by binocular stereopsis is as shown in FIG. 7. If the optical axes of the left and right TV cameras 14 and 15 are parallel, the associated three-dimensional coordinates are calculated by the following formula. Can be calculated.
In FIG. 7, f is a lens focal length, and d is a camera interval. The left coordinate of the corresponding point of the n-th monitoring object 34 is (X
Ln, YLn) and the right coordinate are (XRn, YRn), the coordinate value (Xn, Yn, Z) of the monitoring object 34 in the case of the alarm distance R
n) is represented by Expression (1) of Equation 1.

(Equation 1) Accordingly, the warning distance r on the screen is compared with the approach warning distance R.
Can be expressed by Expression (2) of Expression 2.

(Equation 2)

For the w point (XLnw, YLnw) in the monitoring radius area of the corresponding point n in the left screen 32, the distance coordinates P1, P2 of the radius R centered on the coordinates of the monitoring object 34 are expressed by the following equation (3). 3) It can be expressed by equations (4) and (5).

(Equation 3)

The corresponding area in the right screen 33 is (4)
(7) It can be expressed by equation (8).

(Equation 4)

(6) Saving the monitoring area 35 in a file (means f) A corresponding number is registered in each image array of the monitoring area 39 on the right screen and stored in a file. Similarly, a corresponding number is registered in each image array of the monitoring area 39 on the right screen and stored in a file.

2. Intrusion determination means In the present invention, the monitoring area 35 is subdivided by the monitoring map, so that accurate intrusion determination can be performed. That is, (7) Image input (means g) In FIG. 9, an image is input to the left screen 32 of the TV camera 14.

(8) Extraction of Moving Object (37) (Means h) In FIG. 9, the moving object 37 is extracted from the image input to the left screen 32.

(9) The position of the moving object 37 on the left screen 32 (means i) The position data of the moving object 37 on the left screen 32 is read out from the filed table as a registered number.

(10) Monitoring map information on left screen 32 (means j) Information on a limited monitoring map corresponding to the number on left screen 32 is read from a file.

(11) The position of the moving object 37 on the right screen 33 (means k) The position data of the moving object 37 on the right screen 33 is read from the filed table.

(12) Entering into the monitoring map? (Means 1) On the right screen 33, it is determined whether the moving object 37 has entered the monitoring area 39 on the right screen. If not, the process returns to (7) and repeats the same operation.

(13) Alarm output (means m) In the above-mentioned (means l), if the vehicle has entered, an alarm is output to notify that the vehicle is in a dangerous state.

When the intrusion is determined without subdividing the monitoring area 35 based on the monitoring map as in the present invention, that is, as shown in FIG. 37 is the monitoring area 3 on the left screen
6 and the moving object 37 in the right screen 33 of the TV camera 15 is within the monitoring area 39 on the right screen, it is determined that the moving object 37 is intruding.
Despite being in the malfunction area 38 before and after 5 and deviating from the monitoring area 35, it malfunctions as the intruder. The closer the interval between the TV camera 14 and the TV camera 15 is, the wider the malfunction area 38 is. In the present invention,
Since the monitoring area 35 is subdivided by the monitoring map, such a malfunction area 38 becomes as small as possible.

[0030]

【The invention's effect】

(1) In the present invention, left and right image coordinates corresponding to a monitoring area 35 centering on a monitoring target 34 are calculated in advance, and a monitoring map creating means for creating and storing a monitoring map, and obtained by image processing during monitoring. Monitoring means for searching the monitoring map from the coordinates of the moving object 37 to determine the state of the alarm;
Since the processing is performed using a plurality of image correspondence methods in a cooperative manner, the three-dimensional spatial coordinates of the monitoring target 34 and the moving object 37 are continuously and instantaneously changed by the conventional plurality of cameras. In comparison with a method of calculating the degree of danger from the separation distance based on the changing spatial coordinates of the two, the processing is simpler and requires a smaller device.

(2) There is no need to install protective means such as ropes and fences around the monitoring area 35, and it is not necessary to temporarily stop power transmission even when the dangerous area is a substation or transmission line. .

(3) Compared to surveillance by witnesses, the surveillance according to the present invention does not malfunction even if it takes a long time.

(4) In the planar image processing monitoring method using one TV camera, a human must constantly monitor the monitor screen, but the present invention employs a stereo method using two television cameras. Since monitoring is performed, it is possible to sufficiently cope with approach in the depth direction, and there are almost no restrictions on the installation location and monitoring direction.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of a method and an apparatus for monitoring intrusion into a monitoring area according to the present invention.

FIG. 2 is a detailed flowchart of creating a monitoring map in FIG. 1;

FIG. 3 is a block diagram showing an embodiment of a method and an apparatus for monitoring intrusion into a monitoring area according to the present invention.

FIG. 4 is a view showing a monitoring object 34 in a field of view of a left screen 32 and a right screen 33 by two TV cameras 14 and 15 installed in parallel, and monitoring a radius warning distance R around the monitoring object 34; It is a top view in the state where the area 35 is inputting an image.

5 is a left screen 3 based on the warning distance R of the monitoring area 35. FIG.
FIG. 9 is an explanatory diagram of a state in which a left screen upper monitoring area 36 is calculated above 2;

FIG. 6 is an explanatory diagram of a state where numbers corresponding to respective image arrangements of a monitoring area on a screen are assigned and stored in a file.

FIG. 7 is an explanatory diagram of a state where a monitoring area on the right screen is calculated on the right screen corresponding to an n-th point on the left screen.

8A is a plan view showing FIG. 7 in two dimensions x and y, and FIG. 8B is a plan view showing FIG. 7 in two dimensions z and x.

FIG. 9 is an explanatory diagram of a case where the monitoring area 35 is subdivided by the monitoring map and a case where the subdivision is not subdivided.

FIG. 10 is an explanatory diagram of a state where a crane truck is working near a monitoring target object 34;

11 is an explanatory diagram of a monitoring area 35 around a monitoring target 34. FIG.

[Explanation of symbols]

11 visual device, 12 measurement processing device, 13 alarm device, 14 TV camera, 15 TV camera, 16 A /
D converter, 17 A / D converter, 18 image measurement processing unit, 19 ROM, 20 RAM, 21 moving object coordinate extraction unit, 22 monitoring map processing unit, 23 intrusion determination unit,
24: alarm transmission unit, 25: alarm output unit, 30: left objective lens position, 31: right objective lens position, 32: left screen, 3
3 right screen, 34 monitoring object, 35 monitoring area, 36
... monitoring area on left screen, 37 ... moving object, 38 ... malfunction area, 39 ... monitoring area on right screen.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G08B 19/00 G08B 19/00 21/00 21/00 E

Claims (4)

[Claims] A surveillance map creating means for preliminarily calculating left and right image coordinates corresponding to a surveillance area around a surveillance object, and creating and storing a surveillance map by a stereo method using a plurality of TV cameras. And monitoring means for searching the monitoring map from the coordinates of the moving object 37 obtained by the image processing at the time of monitoring and determining the state of the alarm, and monitoring the intrusion into the monitoring area. The surveillance map creating means places the surveillance object in the field of view of a left screen and a right screen with two TV cameras and arranged in parallel, and includes a surveillance area. Input means for inputting an image, and a monitoring object 34, a monitoring object setting means for setting a three-dimensional space of an alarm distance R around the monitoring object 34 as a monitoring area 35, and the alarm distance R A means for calculating a left monitor area 36 on the left screen 32 based on the left screen 32, a means for attaching a number corresponding to the coordinate value of each image array in the left screen monitor area 36, and storing the number in a file, Means for calculating a right-screen monitoring area 39 on the right screen 33 corresponding to the n-th point on the screen 32, and a number corresponding to the coordinate value of each image array of the right-screen monitoring area 39, and Means to save in The method for monitoring intrusion into a monitoring area according to claim 1. 3. The monitoring means includes means for inputting an image on the left screen 32, means for extracting the moving object 37 from the image input on the left screen 32, and the position data of the moving object 37 on the left screen 32. Means for reading from the file as numbers registered in the file, means for reading limited monitoring map information corresponding to the numbers on the left screen 32 from the file, means for reading the position data of the moving object 37 on the right screen 33 from the file. Means for judging whether or not the moving object 37 has entered the monitoring area 39 on the right screen, and means for outputting an alarm to notify that the subject is in a dangerous state if it has entered. 3. The method for monitoring intrusion into a monitoring area according to claim 2. 4. A visual device 11, a measurement processing device 12, and an alarm device 13. The visual device 11 includes two TV sets.
Cameras 14 and 15 are arranged in parallel at a fixed interval, and the measurement processing device 12
A / D converters 16, 1 coupled to the outputs of 4, 15
7. Image measurement processing unit 18 for measuring and processing the captured image, controlling each circuit, etc., ROM 19 and RAM 20 coupled to this image measurement processing unit 18, and moving object coordinate extraction for extracting the coordinates of moving object 37 A monitoring map processing unit 22 that processes a monitoring map of a monitoring area 35; an intrusion determining unit 23 that determines whether the vehicle is in a danger area; the warning device 13 includes a warning transmitting unit 24 that outputs a warning signal;
An intrusion monitoring device for entering a monitoring area, comprising an alarm output unit 25 that issues an alarm by light, sound, or the like.