JPH08210912A - Flame detection device - Google Patents

Abstract

PURPOSE: To provide a device which can accurately detect a flame even if the flame flickers or the brightness of the flame changes. CONSTITUTION: An image pickup means 2 such as a CCD camera or the like picks up an image through an image pickup optical unit 1 in a predetermined watching range so as to outputs an image signal. A position detection means 3 detects the position and size of a flame from the image signal so as to send a detection signal to a focusing range setting means 5. The means 5 judges the position and size of burning stuff beneath the flame based on the detection signal so as to set a focus area corresponding thereto. A focus adjusting means 6 detects a focusing position from the image signal in the set focus area so as to control the focusing optical unit drive means 4. A distance detection means 7 detects a distance to the flame from the detected focusing position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a flame detection device used in a fire monitoring and extinguishing system.

[0002]

2. Description of the Related Art Currently, in a fire monitoring and extinguishing system, a TV camera (CC
D camera) is used to monitor the flame within a predetermined monitoring range. In order to focus the camera in the above system, for example, as shown in FIG. 8, a high frequency component is extracted from the video signal from the CCD camera, the optical system is scanned from the near point to the far point, and the result is obtained. In addition, a contrast detection method is used in which the focus position is detected from the peak position of the high frequency component. In this case, as shown in FIG.
The range in which high-frequency components are extracted from the image, that is, the focus range (focus area) of the subject to be focused can be set arbitrarily.

[0003]

When focusing is performed by the contrast detection method, a stationary subject is accurately focused, but when the subject is a flame, the flame is generated as shown in FIG. Because it fluctuates and the brightness of the flame changes moment by moment,
The flame came out of the focus area and could not be focused on the flame, resulting in poor accuracy. This is because the focus area was set from the flame itself.

The present invention aims to solve the above-mentioned problems by paying attention to the fact that there is always a combustion product under the flame, and adopting a method of focusing on the combustion product under the flame.

[0005]

In order to achieve the above object, the flame detection apparatus of the present invention is an image pickup optical system having a focusing optical system, and a predetermined range is imaged through the image pickup optical system to obtain a video signal. Imaging means for outputting, and position detecting means for detecting the position and size of the flame from the video signal from the imaging means,
Focusing optical system driving means for driving the focusing optical system, and the position and size of the burning material under the flame are judged based on the detection signal from the position detecting means, and the focusing range corresponding thereto is determined. Focusing range setting means for setting a focusing range setting means for controlling the focusing optical system driving means by detecting a focusing position within the set focusing range from the image signal from the image pickup means, And a distance detecting unit that detects a distance from the detected in-focus position to the flame.

[0006]

In the flame detecting apparatus of the present invention, when a flame is detected from the video signal, the position and size of the burned material under the flame are determined from the center of gravity of the flame and the size in the horizontal / vertical directions. Judgment is made, a focusing range (focus area) corresponding to this is set, and the flame position is measured while focusing on this focus area.

[0007]

Embodiments of the present invention shown in the drawings will be described below.
FIG. 1 shows a basic configuration of an embodiment of a flame detection device of the present invention. In FIG. 1, 1 is an image pickup optical system having a focusing optical system (and zoom optical system), and 2 is a predetermined optical system through this image pickup optical system. The image pickup means, which is a CCD camera for picking up an image of the monitoring range of the image pickup device, 3 is position detection means for detecting the position and size of the flame from the image signal from the image pickup means, and 4 is the focusing optical system for driving the focusing optical system 1. The system drive means 5 determines the position and size of the burned material under the flame on the basis of the detection signal from the position detection means 3, and sets the focus range (focus area) corresponding to this. Setting means 6 is a focus adjusting means for controlling the focusing optical drive means 4 by detecting a focusing position within the set focus area from the image signal from the image pickup means 2, and 7 is the detected focusing position. Distance detection to detect the distance to the flame more Means, it is.

In the flame detecting apparatus of the present invention comprising the above-mentioned means, in view of the fact that it is difficult to reliably detect the flame as described above, the focus position is determined from the information on the combustion product under the flame, not the flame itself. It is characterized by setting.
That is, as shown in FIG. 2, there is always a burnt substance corresponding to the size of the flame under the flame. Therefore, as shown in FIG. 3, the color temperature based on the color image based on the video signal from the image pickup means 2 is used. The flame is detected in consideration of the above, the position and size of the burned material are judged from the center of gravity of the flame, the size of the flame in the horizontal / vertical directions, etc., and the corresponding focus area (window) is set, and the setting is made. Focus on the focused area and measure the flame position. Combustibles are illuminated by the flame and have the advantage of being easy to focus.

FIG. 4 shows a monitoring mechanism portion of an example of a fire extinguishing system to which the flame detection device of the present invention is applied. The color TV camera 11 is configured using a charge coupled device (CCD). An image pickup optical system 13 is attached to the TV camera 11 via a C mount adapter 12, and the TV camera 11 is attached to an attachment plate 15 by a holder 14. The imaging optical system 13 is an optical system having a focusing optical system and a zoom optical system. The imaging optical system 13 has a distance ring 16 and a zoom ring 17, and a zoom drive gear 18 is attached to the zoom ring 17. A geared motor 22 and a potentiometer 23 are attached to the distance ring drive gear 19 via gears 20 and 21. The zoom drive gear 18 includes gears 24 and 25.
Via the geared motor 26a and potentiometer 26
b is attached. The distance ring 16 and the zoom ring 17 are driven by the geared motors 22 and 26a, respectively, and driven by the geared motors 22 and 26a, respectively, and the respective positions are detected from the resistance values of the potentiometers 23 and 26b.

FIG. 5 shows a circuit configuration of this fire extinguishing system. The auto focus (AF) drive unit 27 is configured using a geared motor 28 and a potentiometer 29,
The geared motor 28 moves the focusing optical system of the imaging optical system 13. The potentiometer 29 detects the position of the focusing optical system of the imaging optical system 13 by the resistance value in conjunction with the focusing optical system of the imaging optical system 13. Geared motor drive circuit 3
0 refers to the resistance value of the potentiometer 29 to drive and rotate the geared motor 28. Further, the zoom controller 31 drives and rotates the geared motor 22 while referring to the resistance value from the potentiometer 25a. The image signal from the CCD camera 11 is used as the automatic focusing device 3
2, input to the host system 33 and monitor 34,
The monitor 34 displays the image captured by the CCD camera 11. Further, the fire extinguishing nozzle 35 is for extinguishing a fire within a predetermined monitoring range, and the horizontal rotation drive mechanism 3
It is rotationally driven in the horizontal direction by 6 and is rotationally driven in the vertical direction by the vertical rotating mechanism 37. Horizontal rotation drive mechanism 36
And the vertical rotation mechanism 37 is driven by a drive circuit 38,
Further, the fire extinguishing nozzle 35 is on / off controlled by the drive circuit 38. The mounting plate 15 is rotatably mounted on the base and is rotated in the horizontal and vertical directions by the imaging system rotation mechanism 9. The imaging system rotation mechanism 39 is driven by a drive circuit 40, and a reset signal from a reset switch 41, which is operated after a fire is extinguished by an observer, is input to the host system 33.

The host system 33, as shown in FIG.
It has an A / D conversion unit 42, a binarization unit 43, an image memory 44, a flame detection unit 45, and a control unit 46, and the video signal from the TV camera 11 is A / D converted by the A / D conversion unit 42 and then 2
By the binarization by the binarizing unit 43 at a predetermined binarization level, only the flame portion becomes the white level. The image signal from the binarizing unit 43 is stored in the image memory 44 for each pixel, and the image memory 44 stores a new image signal every time the binarizing unit 43 outputs an image signal for one screen. Can be rewritten. The flame detection unit 45 calculates the number of white level pixels in the image signal stored in the image memory 44, compares the calculation result with a comparison value stored in advance, and when the calculation result is equal to or larger than the comparison value. The white level part is detected as a flame. The operation of the flame detection unit 45 as described above is repeatedly performed. The control unit 46 controls the A / D conversion unit 42, the binarization unit 43, the image memory 44, and the flame detection unit 45, and also performs the processing described below.

As shown in FIG. 7, the automatic focusing device 32 includes a gate circuit 47, a detection area setting unit 48, a high-pass filter (H
PF) 49, peak hold circuit 50, A / D converter 5
1, the image signal from the TV camera 11 selectively passes through a specific scanning line portion in the gate circuit 47 by the signal from the scanning line setting unit 48. This gate circuit 47
Only the high frequency component is extracted from the image signal from the HPF 49, the peak is detected and held by the peak hold circuit 50, the amount of the high frequency component is detected, and the A / D converter 51 performs A / D conversion. . The automatic focusing device 32 detects the focusing position based on the image signal from the A / D converter 51, controls the AF motor drive circuit 30 based on the detection result, and sets the focusing optical system of the imaging optical system 13 to the focusing position. Adjust the focus by moving to.

The control unit 46 of the host system 33 controls the position of the zoom optical system of the image pickup optical system 13 by controlling the zoom controller 31 so that the TV camera 11 takes an image of the entire predetermined monitoring range in the initial state. Then, it is repeatedly determined from the output signal of the flame detection unit 45 whether or not a flame has occurred within the monitoring range. When a flame occurs within the monitoring range, the control unit 46 processes the image signal from the TV camera 11 to detect the position of the flame on the image pickup surface of the TV camera 11 as described below, and according to the position of the flame. While controlling the drive circuit 40 to rotate the mounting plate 15 horizontally and vertically in the imaging system drive mechanism 39 so that the flame comes to the center of the imaging surface of the TV camera 11, the flame is kept constant on the TV camera 11. The image of the flame is enlarged by controlling the position of the zoom optical system of the image pickup optical system 13 by controlling the zoom controller 34 so as to have a size. Alternatively, the image of the flame is magnified by controlling the zoom setting means to reach a predetermined zoom position set in advance.

Next, the control unit 46 determines the size and position of the burned material under the flame based on the position and size of the flame detected by the flame detection unit 45, and determines the focus area corresponding to that. It is set in the detection area setting unit 48 of the automatic focusing device 32. This causes the automatic focusing device 32 to perform the focus adjustment as described above to focus on the flame, and from the position of the focusing optical system detected by the encoder 29 based on the position of the focusing optical system in the initial state. Measure the distance to the flame. Therefore, the position and distance of the flame on the imaging surface are measured, and the three-dimensional position is measured. Then, the control unit 46 controls the drive circuit 38 so that the fire extinguishing agent such as water from the fire extinguishing nozzle 35 is discharged to the flame depending on the position of the flame and the distance to the flame, and controls the fire extinguishing nozzle 35 in the horizontal and vertical directions. Rotate to. Next, the control unit 46 controls the drive circuit 38.
Then, the fire extinguishing nozzle 35 is turned on, and the extinguishing agent is discharged from the fire extinguishing nozzle 35 to the flame. As a result, the fire extinguishing agent such as water from the fire extinguishing nozzle 35 is accurately applied to the flame irrespective of the size of the flame, the distance, and the size of the monitoring range. After the flame is extinguished, when the reset switch is pressed by the observing person to input the reset signal, the driving circuit 38 turns off the fire extinguishing nozzle 35 so that the CCD camera 11 captures an image of the entire predetermined monitoring range. Then, the zoom controller 31 is controlled to return to the initial state.

Regarding the detection of flame in the above fire extinguishing system, the host system 33 stores the image signal from the A / D converter 42 in the initial state in the initial value memory in advance for each pixel, and then the A / D. The image signal from the conversion unit 42 is repeatedly stored in the flame memory for each pixel, the difference between the image signal in the initial value memory and the image signal in the flame memory is taken for each pixel, and the color is detected by the temperature sensor in the monitoring area. It is also possible to detect the temperature and determine whether or not a flame is generated based on the signal from the temperature sensor and the difference.

[0016]

As described above, according to the flame detection apparatus of the present invention, the focus area is set and the focus is adjusted in correspondence with the burning material under the flame, so that the flame fluctuates, Even if the brightness of the flame changes every moment, the position of the flame can be accurately measured.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation principle of the present invention.

FIG. 3 is a diagram for explaining a flame detection operation of the present invention.

FIG. 4 is a side view showing a monitoring mechanism section of an example of a quenching system to which the present invention is applied.

FIG. 5 is a block diagram showing a circuit configuration of the fire extinguishing system.

FIG. 6 is a block diagram showing a part of a host system in the fire extinguishing system.

FIG. 7 is a block diagram showing a part of an automatic focusing device in the fire extinguishing system.

FIG. 8 is an operation explanatory diagram of a conventional device.

9 is an explanatory diagram of a focus area setting method in the conventional apparatus of FIG.

10 is an explanatory diagram of a problem of the conventional device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Imaging optical system 2 Imaging means 3 Position detection means 4 Focusing optical system drive means 5 Focusing range setting means 6 Focus adjustment means 7 Distance detection means

Claims (1)

[Claims] 1. An image pickup optical system having a focusing optical system, image pickup means for picking up a predetermined range through the image pickup optical system and outputting a video signal, and a position and a size of a flame based on the video signal from the image pickup means. Position detecting means for detecting the height, focusing optical system driving means for driving the focusing optical system, and determining the position and size of the burning material under the flame based on the detection signal from the position detecting means. Then, focusing range setting means for setting a focusing range corresponding thereto, and a focusing optical system driving means for detecting a focusing position within the set focusing range from a video signal from the image pickup means. A flame detection device, comprising: a focus adjustment unit that controls the distance and a distance detection unit that detects a distance from the detected in-focus position to the flame.