JPH08138169A - Device and method for detecting flame - Google Patents

Abstract

PURPOSE: To surely and correctly detect information such as the scale and location, etc., of flame by using the visual field angle and arrangement condition of an image pick-up means in an image processing calculation at the time of executing the image processing calculation concerning flame detection. CONSTITUTION: The device is provided with an image pick-up part 1 picking-up an image within the range of visual field angle, an arrangement condition input part 2 inputting the arrangement condition of the image pick-up part 1, an arithmetic part 3 executing the image processing calculation concerning flame detection based on picked-up image data, an output part 4 outputting flame detection result and a power source part 5 supplying a power source. In this case, the arrangement condition input part 2 any be constituted as a distance meter which automatically measures the height (h) of the image pick-up part 1 or/and an inclination meter which automatically measures the inclination angle θ (θx , θy ) of the image pick-up part 1 to the vertical direction. Then, these measure instruments are previously fixed to the image pick-up part 1 and the output from the measure instruments are inputted to the arithmetic part 3, so that the arrangement condition are automatically inputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame detecting device and a flame detecting method for detecting a flame.

[0002]

2. Description of the Related Art Conventionally, as a device for detecting a fire, for example, a fire detecting device as disclosed in JP-A-1-251297 has been known. This fire detection device is shown in FIG.
As shown in, a light receiving element array for detecting light from the flame 40
It has a (CCD) 10 and a slit mask 50 provided between the flame 40 and the light receiving element array 10, and whether or not each data from each light receiving element has a predetermined level or more. If there is data of a predetermined level or more, it is determined whether or not the pattern based on the data is the target of fire pattern recognition (because normal flame has a flicker of about 8 Hz, Based on this frequency, it is judged whether or not it is a target of fire pattern recognition), and when it is judged as a flame, the slit mask 50 and the light receiving element array 10
The flame 4 according to the distance between the flame 40 and the end positions Q7 to P7 and Q8 to P8 of the flame 40 on the light receiving element array 10.
The distance W to 0 is obtained, and the width W of the flame 40 is further calculated based on the distance to the ends a and b of the flame 40 thus obtained. When the state of being WC or higher continues for a predetermined time, an alarm is output. In FIG. 15, reference numeral 51 is a slit, and reference numeral 52 is an infrared filter.

[0003]

However, in the above-described conventional fire detection device, it is necessary to provide the slit mask 50 on the front surface of the light receiving element array (CCD) 10 and the flame 40
Since it is necessary to use the distance between the slit mask 50 and the light receiving element array 10 to detect the distance from the flame and the width W of the flame, in order to reliably detect the flame, the slit mask 50, that is, the slit 51. However, there is a problem in that it is not possible to accurately detect the information regarding the flame even if the setting of the position and distance of the slit mask 50 with respect to the light receiving element array 10 is slightly deviated. It was

According to the present invention, when a flame is imaged to detect information about the flame, the information about the flame can always be detected stably, reliably and accurately without installing a slit mask or the like. An object is to provide a flame detection device and a flame detection method.

[0005]

In order to achieve the above object, the present invention provides an image processing relating to flame detection based on image data obtained by capturing an image in a range of a predetermined viewing angle by a predetermined image pickup means. When performing the calculation, the viewing angle of the image pickup means and the installation condition of the image pickup means are used in this image processing calculation. As a result, it is possible to reliably and accurately detect information about the flame, specifically, information such as the scale and position of the flame, only by the viewing angle of the imaging means and the installation conditions without installing a slit mask or the like. it can.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a flame detection device according to the present invention. Referring to FIG. 1, the flame detection device according to the present exemplary embodiment has an imaging unit 1 that has a predetermined viewing angle and that captures an image in the viewing angle range, and an installation condition that inputs installation conditions of the imaging unit 1. An input unit 2, an arithmetic unit 3 that performs image processing arithmetic relating to flame detection based on image data captured by the image capturing unit 1, an output unit 4 that outputs a flame detection result, and a power supply unit 5 that supplies power. have.

In the example of FIG. 1, the image pickup section 1 has an image pickup element (for example, CCD sensor) 11 and an optical means (for example, optical lens) 12 having a predetermined viewing angle (angle of view). FIG. 2 shows a specific example (plan view) of the image pickup unit 1 in which the optical lens 12 is incorporated in the CCD sensor as the image pickup element 11.
It is shown. In FIG. 2, the optical lens 12
And the CCD sensor 11 are shown as overlapping. Further, in FIG. 2, reference numeral 13 is an operating light, and
Power is supplied to the CD sensor 11 from the power supply unit 5, and the CCD
When the sensor 11 is operating, the operating light 13 is turned on.

Further, in order to suppress the influence of sunlight or the like and reliably capture only the flame, the image pickup unit 1 has a filter (for example, a sharp cut filter; a filter number) having an infrared transmission characteristic as shown in FIG. IR-82, IR-8
4, IR-86, IR-88, or IR-90) may be further provided. FIG. 4 is a diagram mainly showing a flame (gas flame) in the ultraviolet and visible regions and a spectral characteristic of sunlight, and as can be seen from FIG. 4, a flame (gas flame) in the ultraviolet and visible regions.
Has a lower relative sensitivity (relative intensity) than sunlight. Also,
FIG. 5 is a diagram showing the spectral characteristics of the flame in the infrared region. From FIG. 5, it can be seen that the flame (light emitted from the flame) has the maximum relative intensity at a wavelength of 4.3 μm. Therefore, from the spectral characteristics of FIGS. 4 and 5, for example, 800 to 1000 nm
800-1000n by cutting light of shorter wavelength than
By providing the filter as shown in FIG. 3 that transmits light having a wavelength longer than m, it is possible to suppress the influence of sunlight or the like and obtain a flame image. Such filters are
For example, it may be provided between the optical means (optical lens) 12 and the image pickup element (CCD sensor) 11, or may be provided by coating on the optical means (optical lens) 12.

FIG. 6 is a perspective view showing an example of a room in a building. As shown in FIG. 6, the image pickup unit 1 is, for example, a ceiling 102 or a wall surface 103 of a predetermined room 101 in the building.
The image picked up by the image pickup device 11 is installed at a high position, and the viewing angle (angle of view) of the optical lens 12 and the installation condition of the image pickup unit 1 (the floor 10 of the room 101).
4, the height h of the image pickup unit 1 from 4 and the installation angle of the image pickup unit 1
(Tilt angle) θ). Therefore, room 1
When a desired surveillance area in 01 is to be monitored, an optical lens 12 having a predetermined viewing angle is used, and the room 1
It is necessary to previously install the image pickup unit 1 at a predetermined position in 01 at a predetermined angle θ.

7 (a) and 7 (b) are cross-sectional views in the x-axis direction and the y-axis direction of FIG. 6, respectively. FIGS. 7 (a) and 7 (b) show the desired monitoring area in the room 101. To monitor 105,
The imaging unit 1 having a predetermined viewing angle θ ₀ (θ _x0 , θ _y0 ) has a predetermined tilt angle (a tilt angle from the vertical line z) θ at a predetermined position.
The installation state is shown at (θ _x , θ _y ). Note that θ
_x and θ _y are the x-axis direction component and the y-axis direction component of the tilt angle θ, and θ _x0 and θ _y0 are the x-axis direction component and the y-axis direction component of the viewing angle θ ₀ , respectively.

Further, in FIG. 8, the image pickup unit 1 is shown in FIG.
When installed as shown in (b), the CCD sensor 11
An example of a screen imaged by is shown. In the example of FIG. 8, this screen is, for example, the number of pixels of the CCD sensor.
Corresponding to (number of elements) N × M, the pixel is divided into N and M (for example, 60 and 60) pixels in the x-axis direction and the y-axis direction, respectively. That is, one pixel of the imaged screen is CC
It corresponds to one pixel of the D sensor.

CCD sensors include those with a high resolution of several hundreds of thousands of pixels to those with a low resolution of several tens of pixels, and any of these can be used. In this case, when a low-resolution CCD sensor is used, the output of each pixel of this CCD sensor can be directly used as the image data to be processed, and in this case, each pixel of the screen is as described above. Each pixel has a one-to-one correspondence. Further, when a high-resolution CCD sensor is used, each pixel output of this CCD sensor can be directly used as image data to be processed, but in order to simplify the subsequent image processing, in the image pickup unit 1 or In the arithmetic unit 3, a plurality of pixel outputs of the CCD sensor may be collected (for example, by taking the average of the plurality of pixel outputs) to form one pixel as image data. For example, when the CCD sensor has 64 × 64 pixels, that is, 4096 pixels, by compressing 4 pixels into 1 pixel (for example, taking the average value of the levels of 4 pixels and setting this as the level of 1 pixel) 16 × 1)
Since the image data has 6 pixels, that is, 256 pixels, the time required for image processing can be shortened. However, the resolution decreases accordingly.

The arithmetic unit 3 monitors the screen imaged in this manner, for example, periodically (at a constant time interval T), and basically, the image data of the current screen and the image data of the previous screen. , And when there is a changed part between the image data of the current screen and the image data of the previous screen,
A determination process is performed to determine whether or not the changed portion is a flame (for example, a flame caused by a fire).

In the example shown in FIG. 1, the arithmetic unit 3 has analog image data (that is, for example, the CCD sensor 1) from the image pickup unit 1.
A / D converter 20 that performs analog-to-digital conversion for each pixel output (1), a processor (CPU) 21 that performs the above-described monitoring processing, determination processing, and the like based on digitally converted image data, and a processor 21. It has a ROM 22 in which a processing program and the like are stored and a RAM 23 which functions as a work area of the processor 21, and the image data of the current screen used in the above processing, the image data of the screen at the previous time, etc. are stored in the RAM 23. It has become so.

The A / D converter 20 has a function of converting analog image data into binary digital image data by a predetermined threshold value according to the processing capability of the processor 21 and the like. Alternatively, it may have a function of converting the analog image data into multi-valued digital image data using, for example, the brightness (gradation level) at the focal coordinate position as a threshold value. That is, when the processor 21 has a processing capability for multi-valued digital image data, an A / D converter having a function of converting the multi-valued digital image data is used, so that the flame can be more accurately recorded. However, if the processor 21 has only processing capability for binary digital image data, an A / D converter having a function of converting into binary digital image data is used. Or
A / having a function of converting into multi-value digital image data
When the D converter is used, it is necessary to further convert multi-valued digital image data into binary digital image data.

In the following description, for convenience, the analog image data from the image pickup unit 1 is finally converted into binary image data, and the processor 21 performs a predetermined image processing operation on the binary image data. Shall be done. Further, the comparison between the image data at the present time and the image data at the previous time for determining whether or not the image data has changed is made by taking the difference between them and making the difference image data. In this case, since the image data is binarized, the difference image data has all pixel values of “0” when there is no change, and only the changed part has a value other than “0”. Therefore, it is possible to immediately determine whether or not there is a changed portion.

By the way, in order to surely determine in the arithmetic unit 3 whether or not the changed portion of the screen is due to the flame, the arithmetic unit 3 sets the installation condition of the image pickup unit 1 (of the image pickup unit 1). The height h and the tilt angle θ (θ _x ,
θ _y )) is required. Therefore, in this embodiment, the installation condition input unit 2 for inputting the installation condition of the image pickup unit 1 is provided.

The installation condition input unit 2 is, for example, a distance meter that automatically measures the height h of the image pickup unit 1 (that is, the distance from the floor 104), and / or the tilt angle θ of the image pickup unit 1 from the vertical direction z. It can be configured as an inclinometer that automatically measures (θ _x , θ _y ). In this case, these measuring devices are attached to the imaging unit 1.
Installed in advance and outputs the output from these measuring devices to the computing unit 3
Installation conditions can be automatically entered by inputting to. In this case, as a device for measuring the height (distance) h, that is, a distance meter, the ultrasonic wave or the laser light reflected by the floor 104 is emitted from the time when the ultrasonic wave or the laser light is emitted toward the floor 104. A device or the like that measures the distance to the floor 104 by measuring the time up to the point of reception can be used. Further, as the inclinometer, for example, a low-priced, high-performance miniaturized tilt angle sensor manufactured by Lucas Inc. in the United States can be used.

Further, instead of such a rangefinder and an inclinometer, the installation condition input section 2 is used to input the height h of the image pickup section 1 and the installation angle θ (θ _x , θ _y ) as an analog voltage. It can also be configured as an analog voltage regulator. In this case, the operator operates the analog voltage regulator
By adjusting the analog voltages corresponding to the height h and the installation angle θ (θ _x , θ _y ) of the imaging unit 1 (for example, by operating the volume), the height h and the installation angle θ (θ _x , θ
_y ) can be input to the calculation unit 3 as an analog voltage.

Alternatively, the installation condition input section 2 is replaced by the image pickup section 1
The height h and the installation angle θ (θ _x , θ _y ) can be configured as, for example, an 8-bit dip switch for inputting as digital information. In this case, the operator operates the DIP switch to operate the height h and the angle θ.
By setting (θ _x , θ _y ), the height h and the angle θ
(θ _x , θ _y ) can be input to the calculation unit 3 as digital information.

Based on the installation condition input from the installation condition input unit 2, the calculation unit 3 first finds where the position (x _C , y _C ) immediately below the imaging unit 1 is on the screen as shown in FIG. Then, the object OBJ (FIG. 1) corresponding to the portion CH where the image data has changed from the installation position of the image pickup unit 1 is calculated.
Information), the distance L _XY from the installation position of the imaging unit 1 to the object OBJ corresponding to the changed portion of the image data, and the object OBJ corresponding to the changed portion of the image data. Is calculated, and the scale (size) or position of the object OBJ corresponding to the changed portion of the image data is calculated based on the calculated information or the like to determine whether the object OBJ is a flame. It is designed to judge whether.

Here, the position (x _C , y _C ) immediately below the image pickup unit 1 on the screen is calculated as follows. That is, for example, as shown in FIGS.
_Has viewing angles θ _x0 and θ _y0 in the x-axis direction and the y-axis direction, respectively, and is installed with an inclination angle θ _{x in} the x-axis direction and an inclination angle θ _y in the y-axis direction. The angles dθ _x and dθ of one pixel (one section) on the x-axis and y-axis of the screen as shown in FIG.
Each _y is calculated by the following equation.

[0023]

## EQU1 ## dθ _x = θ _x0 / N dθ _y = θ _y0 / M

N and M are the numbers of pixels (the number of sections) in the x-axis direction and the y-axis direction, respectively. 1 pixel on x-axis and y-axis
When the angles dθ _x and dθ _{y of} (one section) are calculated by Equation 1, the position (x _C , y _C ) immediately below the image pickup unit 1 on the screen is obtained by the following equation.

[0025]

[Number 2] _{x C = N / 2-θ} x / dθ x y C = M / 2-θ y / dθ y

FIG. 8 shows the position (x _C , y _C ) immediately below the image pickup unit 1 on the screen thus obtained. As can be seen from FIG. 8, when the tilt angles θ _x and θ _y are 0, that is, when the image pickup unit 1 is not tilted, the position (x _C , y _C ) immediately below the position is the center of the screen. , Tilt angle θ _x
Alternatively, the larger θ _y , the closer (x _C , y _C ) is to the edge of the screen.

In this way, the image pickup unit 1 on the screen
When the position (x _C , y _C ) immediately below is calculated, the angle ψ (vertical line from the installation position of the image pickup unit 1 to the position of the object OBJ corresponding to the changed portion of the image data is used as a reference. z
Can be obtained. More specifically, for example, the object OBJ does not exist at the previous time, and the screen at the previous time is as shown in FIG. 9A. At this point, the object OBJ appears as shown in FIG. The screen at this point is as shown in Fig. 9 (b),
When it is detected that the changed portion of the image data is the portion of the code CH on the screen, that is, the difference between the image data of FIG. 9B and the image data of FIG.
Difference image data as shown in (c) is obtained, and a portion having a pixel value other than “0” in this difference image data (see FIG. 9).
In the example of (c), when a black pixel portion) CH is detected as a changed portion of the image data, information regarding the angle ψ to the actual object OBJ corresponding to this changed portion CH is obtained as follows. be able to.

That is, the changed portion CH of the image data on the screen is (x ₁ , y ₁ ) as shown in FIG. 9C.
In the range of to (x ₂ , y ₂ ), the angular range ψ _{x1 to} ψ _x2 in the x-axis direction from the installation position of the imaging unit 1 to the actual object OBJ corresponding to the portion CH where the image data has changed, The angular ranges ψ _{y1 to} ψ _{y2 in the} y-axis direction are obtained by the following equations, respectively.

[0029]

Equation 3] _{ψ x1 = dθ x × (x} 1 -x C) ψ x2 = dθ x × (x 2 -x C) ψ y1 = dθ y × (y 1 -y C) ψ y2 = dθ y × ( y ₂ -y _C)

As a result, the distance L _XY from the installation position of the image pickup unit 1 to the object OBJ (the distance to the farthest portion of the object OBJ) can be calculated by the following equation.

[0031]

L _XY = (h / cos ψ _x2 ) × (1 / cos ψ _y2 ).

Further, as a result, the actual size | X |, | Y | of the object OBJ in the x-axis direction and the y-axis direction and the actual size S of the object OBJ are expressed by the following equation. It can be calculated.

[0033]

[Expression 5] | X | = L _XY × (ψ _x2 −ψ _x1 ) | Y | = L _XY × (ψ _y2 −ψ _y1 ) S = | X | × | Y |

In this way, S, | X |, | Y | can be obtained as information concerning the size of the object OBJ,
As information on the position of the object OBJ, L _XY , ψ can be obtained.

Each piece of information about the object OBJ as described above is stored in the floor 104 which should be the monitoring area 105 of the room 101.
The portion is a flat plane, and it is obtained on the assumption that the object OBJ is along the flat plane of the floor 104, and the portion of the floor 104 to be the monitoring area 105 has irregularities such as stairs. In this case, it is necessary to make a corresponding correction on each piece of information of the object OBJ. In the following description, for convenience of explanation, it is assumed that the portion of the floor 104 to be the monitoring area 105 is a flat plane.

Further, in the above-mentioned example, the image pickup section 1 can be attached at an arbitrary inclination angle θ (θ _x , θ _y ), but if necessary, this inclination angle θ (θ _x , θ _y). ) Can be restricted. That is, the image pickup device 11 has a CCD
When an element is used, the CCD element is generally rectangular, and one of the x-axis direction and the y-axis direction is longer than the other and the number of pixels is large.
Now, for example, when the length in the x-axis direction is long, when the tilt angle θ _{x in the} x-axis direction is not “0 °” (that is, when the x-axis of this CCD element is not parallel to the floor 104), There may be a shortage in the actual monitoring area in the x-axis direction, or the calculation of the characteristic parameters (size, etc.) of the object OBJ may become complicated, resulting in an error in the characteristic parameters. When the object OBJ is displayed on the monitor, it may be difficult to see the object. Therefore, when a CCD device is used as the image pickup device 11, in the above example, the image pickup unit 1 is attached so that the x axis of the CCD device is parallel to the floor (that is, the tilt angle θ _x is “0 °”). Is good. In other words, in the case of the above example, at least one of the x-axis direction component θ _x and the y-axis direction component θ _y of the tilt angle θ of the image sensor 1 from the vertical line z is set to “0 °”. Is good. At this time, the position of x _C ,
Alternatively, the position of y _C becomes the center on the x-axis of the imaging screen or the center on the y-axis.

In this way, the calculation section 3 collects the image data of the screen periodically (for example, at regular time intervals),
The change in the image data is monitored each time, and when there is a change in the image data, the above information is obtained for the object corresponding to this change, and the state of change of the object is checked to determine the object. I try to judge whether an object is a flame (for example, a flame from a fire).

When the object is a flame due to a fire, this determination processing is performed on a scale (size, area) whose scale (size, area) is considerably larger than that of a flame such as tobacco. Yes, it has a predetermined fluctuation (for example, flicker of about 8 Hz), and the position of the object does not change rapidly with time (for example, its moving speed is different from that of the imaging unit 1). Depending on the distance L _XY , for example, 0 cm / sec.
It should be in the range of about 50 cm / sec.).

That is, the calculation unit 3 determines that the size (area) of this portion is appropriate as a flame due to a fire, for example, from the overall size (area) S of the object OBJ corresponding to the changed portion of the image data. Whether or not the object OBJ has a predetermined fluctuation, and whether or not the object OBJ has a predetermined fluctuation, and whether or not the position of the object is temporally changed is predetermined. It is designed to judge whether or not the speed is within the range.

In the above example, the changed portion of the image data is only one pixel connected region CH, and therefore,
Although only one object OBJ has dealt with the case where the detected changed portion of the image data is a plurality of pixel connected region CH ₁ to CH _n as shown in FIG. 10, a plurality of objects OBJ ₁ ~ If the OBJ _n is detected, the pixel connected regions CH ₁ to CH _n, the arithmetic processing described above for each of the object OBJ ₁ ~OBJ _n is performed, the object O
Information about BJ _{1 to} OBJ _{n such} as size, fluctuation, and temporal change in position is required.

The size of the object corresponding to the changed portion of the image data can be obtained by S,
Based on the sizes | X | and | Y | in the x-axis direction and the y-axis direction, x
It can also be obtained in each of the axial direction and the y-axis direction. In addition, the ratio of the size | X | and | Y | in the x-axis direction and the y-axis direction |
Information about the shape of the object can be obtained by Y | / | X | and the like, and the flame can be determined by adding the information about the shape to the information about the size S.

Next, an example of the processing operation of the flame detecting device having such a configuration will be described with reference to the flowchart of FIG. FIG.
Referring to 1, the processor 21 first performs initialization processing. For example, RAM2 that functions as a work area
Initialization of 3 etc. is performed (step S1). Then, the image monitoring process and the flame detection process are started (step S
2 to S8).

That is, the processor 21 takes in image data from the image pickup section 1 (more specifically, digital image data from the A / D converter 20) at predetermined time intervals T (step S2). For example, as shown in FIG.
The start time of the image processing is t ₁ , and the times t ₁ , t ₂ , t ₃ ,
Image data of D _ij (t ₁ ), D _ij (t ₂ ), D _ij (t ₃ ),
, The processor 21 determines that each time t ₁ , t ₂ , t
₃ , image data D _ij (t ₁ ), D _ij (t ₂ ), D _ij (t ₃ ),
Is taken in and stored in the RAM 23.

At this time, basically, in order to save the capacity of the RAM 23, basically, image data D _ij (t _k ), D _ij (at two time points t _k and t _{k + 1} which are temporally adjacent to each other are set. t _{k + 1} ) is RA
To be held in M23. Specifically, when the processor 21 takes in the image data D _ij (t ₁ ) at time t ₁ ,
This is stored in the area WK ₁ of the RAM 23 as shown in FIG. 13A. Then, when the image data D _ij (t ₂ ) is fetched at time t ₂ , this is stored in the area WK ₂ of the RAM 23 as shown in FIG.
Store as shown in (b). At this point, the RAM 23 stores the image data D _ij (t ₁ ) and D 2 at the two times t ₁ and t _2.
ij (t ₂ ) is held. Next, at time t ₃ , the image data D
_{When ij} (t ₃ ) is fetched, the image data D _ij (t ₁ ) at time t ₁ held in the area WK ₁ of the RAM 23 is deleted,
Instead of this, the image data D _ij (t ₃ ) at time t ₃ is shown in FIG.
Store as shown in (c). In this way, the image data of the odd-numbered time is stored in the area WK ₁ of the RAM 23,
Area WK of RAM 23 for image data at even time
Store in ₂ .

When the image data D _ij (t _k ) and D _ij (t _{k + 1} ) at the two times t _k and t _{k + 1} are acquired in this way, the processor 21 determines that these two image data D _ij (t _k ), D
_ij (t _{k + 1} ) is compared to determine whether the image data D _ij (t _{k + 1} ) has changed with respect to the image data D _ij (t _k ) (step S3). For example, two binary image data D _ij (t _{k + 1} ),
The difference of D _ij (t _k ) is calculated, and the difference image data (D
_It is judged that there is no change when all the pixel values of _ij (t _{k + 1} ) −D _ij (t _k )) are “0”, and changed when there is a part having a pixel value other than “0”. To judge.

If the result of such determination is that there is no change, the process returns to step S3 again, and the same processing is performed for the next time. Specifically, in the example of FIG. 12, when there is no change between the image data D _ij (t ₁ ) and D _ij (t ₂ ) at the times t ₁ and t ₂ , the image data at the times t ₂ and t ₃ D _ij
(t ₂ ), D _ij (t ₃ ) are compared, and image data D _ij (t ₂ ), D _ij
When there is no change in _ij (t ₃ ), the image data D _ij (t ₃ ) and D _ij (t ₄ ) at the times t ₃ and t ₄ are compared.
Image data D _ij (t _k ) and D _ij (t at two times t _k and t _{k + 1
k + 1} ) is repeatedly compared (steps S2 and S3).

In such repetitive processing, for example, image data D _ij (t ₄ ) and D _ij (t ₅ ) at times t ₄ and t ₅
If a change is found as a result of comparison between
Determines whether or not the change in the image data is due to the flame. That is, as described above, it is determined whether or not the size (and / or shape) of the object OBJ corresponding to this changed portion is appropriate as the size (or shape) of the flame, and It is determined whether or not the object OBJ has a predetermined fluctuation, and further it is determined whether or not the temporal change of the position of the object OBJ is appropriate as the temporal change of the flame.

In order to make this determination, the processor 21
Is only two times t ₄ , t ₅ when a change is observed.
Image data D _ij (t ₄ ), D _ij (t ₅ ), and image data D _ij (t ₆ ), ..., D at times t ₆ , ..., T _m thereafter.
_ij performs processing using a (t _m).

[0049] That is, to perform the determination process of the whether by fire, the image data D _ij of the two times t _4, t ₅ at the time the change was observed (t _4), D _ij ( The size (and / or shape) of the object corresponding to the changed portion is obtained by using only t ₅ ) (by only one difference image data) (S or | X |, | Y | And regarding the shape, for example, the ratio | Y | / | X
It is also possible to judge whether or not this is a flame, and to judge whether or not it is a flame. However, the size (and / or the shape) of the object OBJ is determined only by the comparison result of the two image data D _ij (t ₄ ) and D _ij (t ₅ ) (that is, only the comparison result at the temporary point). However, it is impossible to accurately judge that the object OBJ is a flame. Further, with only one piece of difference image data, a false alarm may occur due to the action of light such as a momentary light. Therefore, in order to make a more accurate judgment, when it is judged that there is a change in step S3, the image data D at the times t ₄ and t _5
ij (t _4), not only the comparison result of D _ij (t _5), further, the subsequent time t _6, ..., also acquires the image data of t _m, the time t
_{It is preferable} to make the determination based on the image data at a plurality of times including the image data D _ij (t ₅ ) of ₅ . For example, time t
Not only the comparison result of the image data D _ij (t ₄ ) and D _ij (t ₅ ) of ₄ and t ₅ , but also the image data D of the subsequent time t ₅ and t _6.
The comparison result of _ij (t ₅ ), D _ij (t ₆ ), ..., The comparison result of the image data D _ij (t _m-1 ), D _ij (t _m ) at the times t _m-1 , t _m is also used. Then, it is preferable to judge whether or not the object is a flame by monitoring the temporal change of the object.

Therefore, in the example of FIG. 11, step S4
When it is determined that there is a change in, the processor 21 further acquires the image data at the subsequent time.
(Step S4). Then, the processor 21, for example, monitors the temporal change of the object as described above, and the size (and / or shape) of which is appropriate as a flame at at least one time point of the temporal change of the object. Or not (step S5), and whether or not the object has a predetermined fluctuation from the temporal change of the object (step S6), and further, the position of the object. It is determined whether or not the temporal change of is unnatural as the temporal change of the flame (step S7). For example, the size S of the object
Alternatively, it is possible to determine whether or not it has a predetermined fluctuation by monitoring the time change of | X | and | Y |. Further, the temporal change of the position of the object can be detected by monitoring the temporal change of the distance L _XY and the angle ψ to the object, and the object OBJ suddenly disappears from the screen or suddenly appears on the screen. If the position of the object changes, moves back and forth on the screen, or does not move at all, it is judged that the temporal change of the position of the object is unnatural as the temporal change of the flame. In other cases than the above, it is determined that the temporal change in the position of the object is natural as a flame.

As a result of these judgments, when it is appropriate as the shape and size of the flame, has the appropriate fluctuation as the flame, and is appropriate as the temporal change of the flame,
A fire alarm is output from the output unit 4 (step S8). For example, a warning lamp is turned on or an alarm sound is generated. If it is not appropriate as the shape and size of the flame, it does not have a proper fluctuation as the flame, or if it is not appropriate as the temporal change of the flame, it is not judged as the flame and the process returns to step S2 again.

The process after the change in the image data is confirmed, that is, the process of comparing the image data D _ij (t ₄ ), D _ij (t ₅ ), ..., The image data D _ij (t _m-1 ). , D _ij (t _m ), two image data, for example, D _ij (t _m−1 ),
It is also possible to monitor the size (and / or shape), fluctuation, and movement (position) of the changed part by taking a simple difference between D _ij (t _m ), but a change was confirmed in the image data. After that, since the object exists in the image data at the previous time point, if a simple difference is taken, the difference image data shows the portion CH (t _k ) of the object at the current time as shown in FIG. In addition, the part CH (t _k-1 ) of the object at the previous time appears,
Processing may be complicated.

To avoid this problem, for example, the image data D _ij (t ₄ ) immediately before the change is recognized (time t ₄ ) is used as the standard image data, and the image data D _ij (t ₅ ) after the time t _{5 is used.} ，
When D _ij (t ₆ ), ..., D _ij (t _m ) are sequentially obtained, each image data D _ij (t ₅ ), D _ij (t ₆ ), ..., D _ij (t _m ) and the standard The difference with the image data D _ij (t ₄ ) is calculated, and each difference image data
(D _ij (t ₅ ) −D _ij (t ₄ )), (D _ij (t ₆ ) −D _ij (t ₄ )),
, (D _ij (t _m ) −D _ij (t ₄ )), the size (and / or shape) of the changing part, the fluctuation,
It is also possible to calculate the position and the like and judge whether the object corresponding to this portion is a flame or not from the lapse of time.

Alternatively, it is possible to determine whether or not the flame is present by any desired image processing other than the above-described image processing.

Further, in the above example, when a change is recognized in the image data, the object corresponding to the changed portion of the image data is appropriate as the size (and / or shape) of the flame, and A fire alarm is output when there is fluctuation as a flame and it is appropriate as a temporal change in the flame, but as a preceding step, image data at each time after the time when the change was recognized in the image data Can also be displayed on a display or the like. That is, the changed portion of the image data can be visually displayed as a moving image on a display or the like.

Further, the operator is also notified by outputting information S, | X |, | Y | of the size of the object obtained for judging the flame and information L _XY , ψ about the position. Is also possible.

As described above, according to the present embodiment, when a flame is imaged to detect information about the flame, the flame can be detected only by the installation condition of the image pickup unit 1 without installing a slit mask or the like. Information can always be detected stably, reliably and accurately.

[0058]

As described above, according to the present invention, when performing image processing calculation relating to flame detection based on image data obtained by capturing an image in a range of a predetermined viewing angle by a predetermined image pickup means, In this image processing calculation, the viewing angle of the image pickup means and the installation condition of the image pickup means are used. Therefore, even if a slit mask or the like is not installed, only the viewing angle of the image pickup means and the installation condition are used. It is possible to always stably, reliably and accurately detect the information regarding.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a flame detection device according to the present invention.

FIG. 2 is a diagram showing a specific example of an imaging unit.

FIG. 3 is a diagram showing a transmission characteristic of an infrared transmission filter.

FIG. 4 is a diagram showing spectral characteristics of flames in the ultraviolet and visible regions.

FIG. 5 is a diagram showing a spectral characteristic of a flame in an infrared region.

FIG. 6 is a perspective view showing an example of a room in a building.

7A and 7B are cross-sectional views in the x-axis direction and the y-axis direction of FIG. 6, respectively.

FIG. 8 is a diagram showing an example of an imaged screen.

9A to 9C are diagrams for explaining a method of detecting a changed portion of image data.

FIG. 10 is a diagram showing a case where a changed portion of image data includes a plurality of pixel connection areas.

FIG. 11 is a flowchart showing an example of processing operation of the flame detection device of FIG.

FIG. 12 is a time chart showing the timing of capturing image data.

13A to 13C are diagrams for explaining how to store image data in a RAM.

FIG. 14 is a diagram showing an example of difference image data.

FIG. 15 is a diagram for explaining a conventional fire detection device.

[Explanation of symbols]

1 image pickup unit 2 installation condition input unit 3 arithmetic unit 4 output unit 5 power supply unit 11 image pickup device 12 optical means 20 A / D converter 21 processor 22 ROM 23 RAM 101 room 102 ceiling 103 wall surface 104 floor 105 monitoring area h of image pickup unit Height θ (θ _x , θ _y ) Installation angle of the imaging unit (tilt angle)

Claims (7)

[Claims] 1. An image pickup means for picking up an image in a range of the viewing angle having a predetermined viewing angle, an installation condition inputting means for inputting installation conditions of the imaging means, and an image taken by the imaging means. And a calculation unit that performs image processing calculation related to flame detection based on the data, wherein the calculation unit, in the image processing calculation related to flame detection, the viewing angle of the imaging unit and the installation input from the installation condition input unit. A flame detection device characterized by using a condition. 2. The flame detection device according to claim 1, wherein the installation condition input means inputs a height at which the imaging means is installed and an installation angle of the imaging means as installation conditions. Detection device. 3. The flame detection device according to claim 2, wherein the installation condition input means includes a range finder and an inclinometer attached to the image pickup means, and the distance meter measures the height from the floor of the image pickup means. A flame detecting device, characterized in that the angle is measured, the installation angle of the image pickup means is measured by an inclinometer, and the angle is input to the calculation means. 4. The flame detection device according to claim 2, wherein the installation condition input means has a voltage adjustment means for inputting a height and an installation angle of the imaging means as an analog voltage. And flame detector. 5. The flame detection device according to claim 2, wherein the installation condition input means has a digital input means for inputting a height and an installation angle of the imaging means as a code having a predetermined number of bits. A flame detection device characterized by the above. 6. The flame detection device according to claim 1, wherein the image data is processed with one pixel of the image pickup unit as one pixel as necessary, regardless of the resolution of the image pickup unit, or image pickup. A flame detection device, wherein a plurality of pixels of the means are collectively processed as one pixel. 7. A flame detection method for performing an image processing calculation relating to flame detection on the basis of image data obtained by capturing an image of a range of a predetermined viewing angle by a predetermined image pickup means, wherein the image processing calculation relating to flame detection is performed. A flame detection method, characterized in that a viewing angle of the imaging means and an installation condition of the imaging means are used.