JPH01251297A - Fire detector - Google Patents

Abstract

PURPOSE:To obtain the distance between a mask and an element column and the distance from the mask up to the flame in accordance with a flame edge part position on the element column and to further, obtain the width of the flame based on the distance by providing a slit mask between the flame and a light receiving element column. CONSTITUTION:When a mask 50 and a CCD column 10 are in parallel, for a distance l0, the leg of the perpendicular from an edge (a) of a flame 40 is P1 and P4, the leg of the perpendicular from edges P2 and P3 of a slit 51 to a CCD is P5 and P6 and the intersection of straight lines aP2 and aP3 and the CCD is P6 and P8, DELTAaP2P1 and DELTAP2P7P5 are of similar figures, and therefore, l a can be calculated from segments P2P3, P1P2=Za, lo. A distance lb can be calculated in the same way from a flame edge (b). Further, with numeric values lb-la and Za-Zb, a flame width W can be operated by the Pythagorean theorem. The width W of the flame exceeds a prescribed value and when connection is executed for a prescribed time, an alarm is generated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a fire detection device that detects the scale of a fire.

[Prior Art] Conventional fire detection devices (hereinafter simply referred to as "detectors") are provided one for each predetermined warning range, and when the detector receives radiant energy of a predetermined level or higher, It is known to issue an alarm because it is a fire.

[Problems to be Solved by the Invention] As described above, conventional detectors of this type determine fire based on the absolute value of radiant energy received by the detector. Therefore, if the judgment level is set based on flames near the detector, flames occurring far away from the detector cannot be reliably detected; conversely, flames occurring far from the detector will be the standard. If the judgment level is set as follows, even external noise near the detector will be judged as a fire. Therefore, in the above-mentioned conventional technology, there is a problem in that it is difficult to reliably detect flames in a wide range including flames generated near the detector and flames generated far away.

The problem with the above-mentioned conventional technology is that the distance to the flame and the width of the flame cannot be determined.

An object of the present invention is to provide a detector that can determine the distance from the detector to the flame, and also detects the scale of the fire by detecting the distance to the flame and the width of the flame. .

[Means for Solving the Problems] In the present invention, a light receiving element array detects light from a flame, a slit mask is provided between the flame and the light receiving element array, and a distance between the slit mask and the light receiving element array is determined. and the end position of the flame on the light-receiving element row, the distance to the flame is determined.

The present invention further provides for determining the width of the flame based on the distance to the end of the flame.

[Function] The present invention calculates the distance to the flame according to the distance between the slit mask and the light-receiving element array and the end position of the flame on the light-receiving element array. Distance Can Be Accurately Determined According to the present invention, the width of the flame is further determined based on the distance to the end of the flame, so the width of the flame can be determined accurately.

[Example] FIG. 1 is a block diagram showing one embodiment of the present invention.

This embodiment uses a COD image sensor (hereinafter simply rC
CDJ) 10, an A/D conversion circuit 20 that converts the analog signal from this CGDIO into a digital signal, an oscillator 21 that sends clock pulses to the CCD lO and the A/D conversion circuit 20, and an A/D circuit. A data input interface 22 for signals from 20, a RAM (random access memory) 23, and a data output interface 24
, an MPU (micro processor unit) 30 that controls the entire operation of the above embodiment, and a ROM (read only memory) 31.

Further, in the above embodiment, a slit mask 50 having a slit 51 is provided on the front surface of the CCD 10. The slit mask 50 is provided with an infrared filter 52, as shown in FIG. 2(1).

The CCD 10 has a large number of light receiving elements and a gate operated by a read command, and is an example of a light receiving element array that detects light from a flame.

The ROM 31 stores a program that implements the flowchart shown in FIG.

The MPU 30 and the ROM 31 are examples of calculation means for calculating the distance to the flame according to the distance between the slit mask 50 and the light-receiving element row and the position of the flame end on the light-receiving element row. This is also an example of calculation means for calculating the width of the flame according to the distance between the light receiving element array 50 and the light receiving element array and the position of the flame end on the light receiving element array.

Next, the operation of the above embodiment will be explained.

FIG. 2 is an explanatory diagram of the above embodiment, FIG. 2 (1) is a diagram showing the relationship between the flame 40, the slit mask 50, and the CC010, and FIG. FIG. 3 is a diagram showing an example of the output voltage on the CCD lO in FIG.

In this example, the flame 40 is passed from a heat source having one end a and the other end a to the CGD1 through the sleeve) 51.
FIG. 3 is a diagram showing an example of a case where infrared rays are irradiated to 0;

The infrared rays from the end a of the flame 40 pass through the slit 51 and irradiate the range of P7 to P8 on the CCD 10, and the infrared rays from the end a of the flame 40 pass through the slit 51 and irradiate the range of P7 to P8 on the CCD 10.
Irradiates the range Q7 to Q8 on cnio. in this case,
Since a large amount of infrared rays are irradiated in the range of P7 to Q8 on the CCD 10, the output voltage of the CCD 10 in that range is high.

Further, the output voltage gradually increases from Q7 to Pl, and gradually decreases from Q8 to P8. The output voltage of the CCD 10 in areas other than Q7 to P8 is written as 0 in FIG. 2 (2), but this does not apply to areas other than the flame 40 such as inside a tunnel! This is the case when there is no source. Therefore, C.C.D.
The positions of Q7, Pl, Q8, and P8 on P10 can be easily determined.

In addition, in the natural world, in proportion to the environmental level,
Since the output voltage of C0D10 is generated in a region other than Q7 to P8, the positions of Q7, Pl, Q8, and P8 on the CCD 10 can be determined according to the value.

FIG. 3 is an explanatory diagram when calculating the distance #a from the slit mask 50 to one end a of the flame 40 in the above embodiment.

In FIG. 3, the slit mask 50 and C0D10 are parallel, the distance from the slit mask 50 to the CCD 10 is 10, and the perpendicular line drawn from one end a of the flame 40 to the slit mask 50 and the slit mask 50, the CCD
The intersections with 10 are PL and P4, respectively, and the slit 5
Let the left end and right end of 1 be P2 and P3, respectively.

Then, each perpendicular line from P2, P3 to CCD 10 and CC
The intersections with D l O are P5 and P6, respectively, and one end a
The intersection of the straight line extension from to P2 and C0D10 is P
L, one end of the straight line from a to P3 and the CCD
Let the intersection with 10 be P8.

In this case, angle P2. P7. P5 is θa1, and angles P3, P8, and P6 are θa2. Here, for example, "angles P2, Pl, and P5J are angles sandwiched between a straight line including points P2 and P7 and a straight line including points P7 and P5," and the same expressions are used below. do.

Moreover, in the case of the above example, Δa, P2. Pi is ΔP2.
P7. It is similar to P5, and Δa, P3゜Pl is ΔP3
, P8, and P6. Here rΔa, P2
, PIJ are "a triangle surrounded by point a, point P2, and point PL", and will be similarly expressed below.

Then, let the distance from P4 to P5 be Za, the distance from P5 to Pl be xal, the distance from P6 to P8 be xo2, and the distance from P5 to P6 be xo.

Therefore, the following formulas (1) to (2) hold true.

From equation 0 and equation ■, we get the following.

-”-no 1IZa +J1o 11xal”n
o*xat+4 and a@xal Also, from equation (■) and equation 0, it becomes as follows.

, -4Ω, o @ Za +lo llX0
+, Ω, o −xa2= xo2・no +
xa2* la, °, nijo* Za +JLo
-X0=xa2*ua Then, the distance 1h from one end a to the slit mask 50 can be found from the equations (1) and (2) as follows.

−”-1a a xal=Jla *xo2-fLo
*x.

-"-1a (xo2-xal) = sentence 0"XO FIG. 4 is an explanatory diagram for calculating the distance from the other end of the flame 40 to the slit mask 50.

The intersections of the perpendicular line drawn from one end of the flame 40 to the slit mask 50 and the slit mask 50 and CCD 10 are Ql and Q4, respectively.

And each perpendicular line from P2, P3 to CCD l O and C
The intersections with OD I O are Q5 and Q6, respectively, the intersection between the extension of the straight line from one end to P2 and CCD10 is Q7, and the extension of the straight line from one end to P3 and CCD.
Let the intersection with 10 be Q8.

Then, let the distance from Q4 to Q5 be zb, the distance from Q5 to Q7 be xbl, the distance from Q6 to Q8 be zb2, and the distance from Q5 to Q6 be XO.

In this case, angles P2, Q7, and Q5 are θb1, and angles P3, Q8, and Q6 are θb2. In addition, in the case of the above example, Δb, P2, Ql are ΔP2°Q7
, Q5, and Δb, P3, Ql are ΔF
3. Q8. It is similar to Q6.

Therefore, the formulas ■' to ■' can be derived.

Therefore, the following equation (■') can be derived from the above equation (1) and (2).

,”,lo * Zb +lo 11xbl=lo
*xbl+Jlb-xbl-"-no*
Zb=statement bexbl'' Furthermore, the following equation ■' can be derived from the equations ■' and equations ■'.

1'-no lI Zb +io * xo
+lo * xb2= Zb2” no +
Xb2'lb-", la*Zb + sentence 0"
XO=Xb2*flb Then, from the above formulas ``■'' and ``■'', the distance @lb from the other end of the flame 40 to the slit mask 50 can be determined as in the formula ``■''.

, “0 sentence b * xbl=fLb @xb2-fLo
・x.

-°, fLb (zb2-xbl) = lo x.

FIG. 5(1) is an explanatory diagram when determining the width W of the flame 40 in the above embodiment.

In FIG. 5(1), let C be the intersection of the extension of the perpendicular line passing through one end a of the flame 40 to the slit mask 50 and the parallel line passing through the other end of the flame 40 and the slit mask 50. The distance from a to C is lb-sentence a, and the distance between b and C is Za-zb.

Therefore, the width W of the flame 40 can be determined by the Vitagoras theorem, as shown in the following equation.

W=((ub-1a)2+(Za-Zb)2)1/2
5 (2) is an explanatory diagram for determining the distance between R1, which is the center between the left end a and the right end of the flame 40, and R2, which is the center of the slit 51.

Here, the intersection of the perpendicular line from R1 to the slit mask 50 and the slit mask 50 is R3, and the angles R1, R2, R
Let 3 be θH. Also, the distance from R2 to R3 is (xo /2) +Za - (Za -Zb) /2
It is.

Therefore, from R2 to R3 is (Xo +Za +zb) / 2, and R1
Since the distance from to R3 is (!Q, a + b)/2, the angle θH is as shown in the following equation 0.

θH-jan-' [((l all b)/2)/
((IO+Za+Zb)/2)], °, θHgtan-
1 ((JLa+ib)/(xo+Za+Zb))---
-・-0 formula Furthermore, the distance LH from R1 to R2 can be determined by the following [phase] formula. 'LH= [((fLa+i b)/2)? +((xo+
Za+Zb)/:))2) 11/2...[phase]
By using the above formula, the distance @LH from the center of the slit 51 to the flame 40 and the width W of the flame 40 can be determined.

FIG. 6 is a flowchart showing the operation of the embodiment described above.

First, data is fetched from each light receiving element constituting the CCD 10 (SL), and it is determined whether or not there is data of a predetermined level or higher among the respective data (S2). For example, if the energy from the Sm2 flame at a point 1 m away from the detector in the above embodiment is set to a predetermined level, it is determined whether there is any energy above the predetermined level.

If there is data above a predetermined level, it is determined whether the pattern based on that data is subject to fire pattern recognition (S3). This excludes things such as revolving lights, car headlights, and tail lights. The revolving light has a frequency of 2 to 3 Hz, while a normal flame has a frequency of 2 to 3 Hz.
Since it has a flicker of about 8 Hz, it is determined whether or not it is a target for fire pattern recognition based on this frequency.

Then, in S4 to S8, a distance #la from one end a of the flame 40 to the slit mask 50 is calculated.

In this case, first find the position of P7, then find the position of P8 (S4, S5). P7 is determined by looking at the output value from the left on the CCD 10 (see the characteristics in Figure 2 (2)). P8 is the position where the output voltage of C0DIO gradually increases and reaches a predetermined constant value, and P8 is the position where the predetermined amount of the output voltage gradually decreases and settles at the O level (or the environmental level). It is a point. Then, the position of P5 is a known value, and the distance axai is calculated based on the positions of P5 and P7 (
S6). Then, the position of P6 is a known value, and the distance fixa2 is calculated based on the positions of P6 and P8 (S7
), and the distance ra intersection a is calculated using the above formulas (1) to (2) (S8).

Then, in the same way as when calculating the distance @ l a, the distance gI
The calculation is performed (S9).

Next, the width W of the flame is calculated using the formula 0 (S 10
).

If the flame width W is larger than the predetermined value WC, then (S
11) If the width W that is greater than the predetermined amount WC continues for a predetermined time (S12), an alarm is output (S13).
.

The value of the width WC of the predetermined amount or the predetermined time when W greater than WC continues and an alarm is output can be set arbitrarily.

[Effects of the Invention] According to the present invention, the distance from the detector to the flame can be determined, and the distance to the flame and the width of the flame can be detected, so the scale of the flame can be determined accurately. It has this effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. FIGS. 2(1) and 2(2) are explanatory diagrams of the above embodiment. FIG. 3 is an explanatory diagram for determining the distance fa from the left end a of the flame 40 to the detector in the above embodiment. FIG. 4 is an explanatory diagram for determining the distance 'Ialb from the right end of the flame 40 to the detector in the above embodiment. FIG. 5(1) shows the width W of the flame 40 in the above embodiment.
It is an explanatory diagram when calculating. FIG. 5(2) is an explanatory diagram for determining the distance between R1, which is the center between the left end a and the right end of the flame 40, and R2, which is the center of the slit 51, in the above embodiment. FIG. 6 is a flowchart showing the operation in the above embodiment. 10...CCD, 30...MPU, 31...ROM, 50...Slit mask, 51...Slit. Patent Applicant Nomi Disaster Prevention Industry Co., Ltd. Agent Arata Yokubo - Fig. 2 Fig. 3 + -xo→ : Fig. 4: -χ, → 2→ □ Fig. 5 (1) As in ・ 1 1 : ” 1 −−−−−−−Yo2=≠−−I22 ・ jzb:

Claims (2)

[Claims] (1) A light-receiving element array that detects light from a flame; a slit mask provided between the flame and the light-receiving element array; a distance between the slit mask and the light-receiving element array; and the light-receiving element array A fire detection device comprising: distance calculation means for calculating a distance to the flame according to the end position of the flame above; (2) A light-receiving element array that detects light from a flame; a slit mask provided between the flame and the light-receiving element array; a distance between the slit mask and the light-receiving element array; and the light-receiving element array distance calculating means for calculating the distance to the flame according to the end position of the flame above; calculating the width of the flame based on the distance to the end of the flame calculated by the distance calculating means; A fire detection device comprising: width calculation means;