CN1349091A - Relative smog density image detector and its detection method - Google Patents

Abstract

The invention relates to a detector for forming an mage of relative concentration of smoke and detecting method. The detector includes a matrix plane emissive source and receiving end, the former is composed of infrared emitting diodes. The latter is composed of CCD camera with infrared filter plate, forming a face to face detecting method. The coherence filtering method is used to carry on noise removing process, giving good solution of alignment, correstion and monitoring whole space. The invention not only provides accurate dynamic data, but also a dynamic image that can be used in multi points measurement and dyamic 3D monitoring wide space. It also provides effective tool for research smoke kinesiology.

Description

Smog relative concentration image detector and detection method thereof

The present invention relates to the monitoring and the fire detection technology field of smokescope.

Detection is one of effective means that human dependence is scientific and technical and fire is struggled.Smoke monitoring is important in the fire early detection, is the important channel of controlling fires development and minimizing fire damage.The smoke detector that is applied at present in the large space roughly has following several: 1, ion type smog detector, 2, diode-type photoelectric smoke detector, 3, air suction type smoke detector, 4, the reflected light beams smoke detector, 5, image is to single-point type analog prober system.Wherein the diode-type photoelectric smoke detector is generally adopted in the world because it is cheap, be quick on the draw and can be used for than characteristics such as large spaces.But traditional infrared smoke detector is in the large space occasion, because the design of its point-to-point formula and elementary treatment technology make it be applied to there is significant limitation aspect the smoke detection.

By retrieval, smoke detector patent related to the present invention has:

1, application number is 1007226 scattered light formula smoke detector;

2, application number is 85105779 photoelectric smoke sensor;

3, the patent No. is 98122932.8 reflected light beams smoke sensing fire hazard detecting method and device;

4, the patent No. is 99203139.7 multi-channel fire image monitoring warning switch.

Exist following problem in the above patent:

When large space was remote, general signal became very faint, and The noise is very big, and useful signal is submerged in the noise, used above detector to be difficult to pick out cigarette and smokeless; In addition, if in the place that solar radiation or strong infrared radiation source are arranged,, above-mentioned detector was lost efficacy because noise is strong excessively.

Above-mentioned detector can only provide the monitoring of threshold values basically, is used for reporting to the police, concentration that can not continuous monitoring smog, and this is not all right in the research of smog deep layer.

The lighting angle of the sensitivity of reception diode and signal to noise ratio (S/N ratio) and light emitting diode and distance relation are very close, are the essential condition that improves measuring accuracy so aim at. Patent 1,2,3 described infrared eyes all are point-to-point or approximate point-to-point monitorings, be used for difficulty of monitoring rate is carried out in whole space; Patent 4 also can only realize the smoke monitoring on certain bar near linear.Because its general alignment principles is that the normal on emission silicon chip plane and reception silicon chip plane is located on the same line in three-dimensional space all the time, and this is difficult to guarantee; Especially strenuous vibration or large space place are being arranged, the detector that uses this point-to-point diode is to unusual difficulty, and the also corresponding increasing of difficulty of aiming at along with the increase of distance.

Patent 3 described reflected light beams smoke sniffers propose the utilization catoptron and make the technical scheme that sends and accept to be positioned at same end, and solve diode on the surface and aimed at problem, but but the aligning of catoptron becomes a big difficulty; Compensating measure reception amplifier that particularly this scheme adopted and reception measuring amplifier, what compensated is the light intensity variation of emission; Its output and decision circuitry, essence are a comparer, i.e. intercepting is two threshold values up and down.When signal to noise ratio (S/N ratio) reduced, useful signal was buried in the random noise, in any case the intercepting threshold values can't judge correctly that all only way is to strengthen emissive power.In addition, it is the binary signal that 0,1 indivedual points are formed by each point value, can't draw out the motion graphics that smog changes.

The present invention proposes a kind of smog relative concentration image detecting, and a kind of smog relative concentration image detection method of using relevant wavelength detection method proposed, can obtain the smog relative concentration value of high s/n ratio, smokescope be carried out the dynamic solid monitoring of large space.

Fig. 1 is the system chart of smog relative concentration image detector of the present invention, and Fig. 2 is its infrarede emitting diode matrix circuit figure, and Fig. 3 is its communication interface and control circuit figure, and Fig. 4 is the flow chart of relevant wavelength detection method.

Image detector for smoke relative concentration of the present invention is characterized in that comprising infrared light emission source (1), transmitting terminal control Circuit (2), communication interface (3), receiving terminal (4), high speed acquisition equipment (5) and PC treatment facility (6) group Become; Described infrared light emission source (1) be every row by after n infrarede emitting diode (7) serial connection, altogether the m row and The n that forms together * m matrix plane places on the end wall surface of large space; Described receiving terminal (4) employing is provided with red The CCD camera (8) of outer filter plate (9) is connected to PC (6) through high-speed collection card (5); Make infrared The silicon plane parallel of each light emitting diode (7) is in the camera of receiving terminal (4) on photo-emission source (1) matrix plane (8) and filter plate (9), form aspectant emission and reception; Described transmitting terminal control circuit (2) comprises microcontroller Device (10) forms with 2 * m injectron (11) and 2 * m current-limiting resistance (12); The infrared light emission source (1) the anodal termination of upper each row series diode+50V power supply, negative terminal are by interface J26 and transmitting terminal control circuit (2) In current-limiting resistance (12) join the drain electrode of another termination injectron (11) of current-limiting resistance (12), high pressure The source ground of switching tube (11), grid are connected to respectively the I/O mouth of microcontroller (10) P0～P2; Described communication connects Mouth (3) is divided into (13) and (14) two parts: in communication interface (13) and the microcontroller of control circuit (2) one ends Device (10) joins, at the communication interface (14) of PC one end and the socket J25 of the serial port RS232 of PC (6) Join, link to each other with 485 buses between communication interface (13) and (14).

Smog relative concentration image detection method of the present invention is characterized in that adopting following steps:

At first under smokeless state, by PC by serial port RS232 mouth, send startup command to microcontroller (10) through communication interface (3), control circuit (2) is opened n * m matrix plane infrared light emissive source (1) that every row are connected in series the back, are total to the m row and form together by n infrarede emitting diode (7), light signal arrives infrared filter (9), enters CCD camera (8) through excessive space, collect in the PC (6) through high-speed collection card (5), form the infrared image of CCD; Infrared figure is adopted the method for coherent filtering, be about to consecutive frame and add up, find out the maximal value in each bright spot district that is separated by in the infrared figure, store this X, Y coordinate and gray-scale value, and PC deposit the bright image vegetarian refreshments in the bright spot district that in the figure each found around time spot zone zero clearing; Successively this operation is done in each bright spot district, up to having looked for till n * m;

Having under the cigarette state, the current gray level value that each point was found in monitoring just now adopts same coherent filtering method to carry out denoising again; Ask the relative smokescope value of n * m bright spot, and draw out current smog image according to its coordinate; Repeat repeatedly to gather denoising, can draw out the time dependent dynamic relative concentration image of smog.

Compared with prior art, the present invention has the following advantages:

1, the present invention adopts the diode matrix plane on big plane to replace point type emissive source of the prior art, employing replaces reception diode based on the camera of CCD device, thereby form aspectant smokescope detector, solve alignment issues well, made the dynamic solid monitoring of large space become possibility; Detector of the present invention has great advantage than the point-to-point mode of infrared receiving diode on aligning, correction and whole space surveillance.

2, the present invention adopts control circuit (2), can regulate and control the emissive power of infraluminescence pipe, for longer-distance smoke monitoring or when smokescope increases considerably, can heighten emissive power, further improves the remote monitoring precision.Owing to taked the control circuit (2) that cut-offs decision current-limiting resistance (12), can select to make the full conducting of No. two control circuits, one tunnel conducting or not conducting by microcontroller (10) control injectron (11); Not conducting, promptly shut-off circuit is not measured; Generally speaking, when close together, adopt one tunnel conducting; When distance strengthens, then can make two-way all conducting strengthening electric current, thereby improve the precision of remote testing; The precision that received data is changed into smokescope can reach 0.5%, thereby can monitor the smokescope in space well, and can form intelligent alarm system easily.

3, because dot matrix emissive source of the present invention makes last collection value form dot matrix, solved the problem that forms dynamic smog figure; Be not only to set a threshold values, and can obtain continuous relative smokescope value.The present invention can certainly be to setting alarming threshold value in the one or more ranges of linearity in the diode dot matrix, in case smokescope reaches setting value and just thinks fire has taken place, begin to report to the police, and can be used for the measurement and the fire detecting and alarm of multiple spot smog relative concentration, can monitor the Changing Pattern of the smokescope figure of having a few composition in the array simultaneously.

4, adopt the smog relative concentration detector of the present invention's design and the algorithm (data processing method that comprises coherent filtering) of design voluntarily to handle image, removed noise, signal to noise ratio (S/N ratio) has been improved an order of magnitude, improved the precision of measuring, make that the detection of smokescope is more accurate, rapidly, directly perceived; Not only can be detection accurate dynamic data are provided, also provide effective instrument for the research of carrying out smog movement.

5, because the Primary Component of image monitoring of the present invention---with the external world indirect contact takes place by optical lens as sensitive element; this structure guaranteed detector can be protected better, be used more permanent; for long-term dust, humidity effect situation very big antijamming capability is arranged, so detector of the present invention need make rapid reaction to the image information in the fire phenomena applicable to using in the indoor and outdoor surroundings of large space, large tracts of land, many dust, high humility, being applicable to, need provide intuitively and use in the place of fire hazard aerosol fog image information dynamically.

Specify embodiments of the invention below in conjunction with accompanying drawing.

Embodiment 1:

The infrarede emitting diode matrix emissive source (1) of present embodiment smog relative concentration image detector, specifically the infrarede emitting diode that is Φ 5 by 10 * 12=120 external diameter (7) is formed, each row is by ten infrarede emitting diode series connection, totally 12 be listed as, the circuit of this infrarede emitting diode matrix emissive source (1) as shown in Figure 2, the infrarede emitting diode matrix is placed on the metope of an end of large space, make the silicon plane of each diode (7) should be parallel to camera (8) and infrared filter (9) as much as possible; Select 120 diodes (7) of family curve unanimity as far as possible for use, and can and connect the adjustment resistance of 30 Ω～300 Ω at the positive and negative end of each diode (7), 30 Ω among Fig. 2～300 Ω do not draw, and have only few diode to need to adjust in the practice.The diode consistance will be adjusted in full accord very difficult, but the difference that will control emissive power basically is no more than 30%-50%, and this accomplishes than being easier to; And in the difference of this 30%-50%, be the relative smokescope that can obtain in the noise.

Control circuit in the present embodiment (2) by 89C51 single-chip microcomputer (there is the program storage of 4K E2PROM inside), R1-R24 the current-limiting resistance of totally 24 200 Ω, 2.5W (12) and J1-J24 among totally 24 Vn222 MOS injectron (11) form; Anodal termination+50V power supply, negative terminal that infrared light emissive source (1) is gone up every row serial connection diode join by the current-limiting resistance (12) in interface J26 and the transmitting terminal control circuit (2), the drain electrode of another termination injectron (11) of current-limiting resistance (12), the source ground of injectron (11), grid are connected to the I/O mouth of microcontroller (10) P0～P2 respectively; The P0 of single-chip microcomputer 89C51～P2 mouth has 24 I/O lines, control J1-J24 totally 24 Vn222 power MOS pipes conducting and end; The serial connection loops of 10 infrarede emitting diodes of per two power MOS pipes and two 200 Ω resistance common control one route, thus every row diode can be arranged to three kinds of control forms by the break-make of metal-oxide-semiconductor: and the smoke detection distance surpasses 10 meters or make the full conducting of two road metal-oxide-semiconductors when smokescope is higher relatively; Distance 10 meters with interior or relative smokescope hour, only select one road metal-oxide-semiconductor conducting; Do not measure former what one road not conducting of metal-oxide-semiconductor.For example its pin of the programmed control of 89C51 P1.0 is 1, and P1.1 is 0, then J1 conducting, and J24 ends, and at this moment the light emitting diode of 12 pin by J26 row only are connected in series one 200 Ω resistance; When the far away or relative smokescope of distance when big, can be by 89C51 programmed control P1.0=1, P1.1=1 makes one of the light emitting diode row serial connection of 12 pin of J26 be equivalent to the resistance (two 200 Ω resistance and connect then be 100 Ω) of 100 Ω; When this row diode is listed as the not time spent, can make P1.0=0, P1.1=0 ends two-way.

Described communication interface (3) is divided into two parts: what be connected on control circuit (2) one ends is interface (13), R, D pin by 485 devices are connected with RXD, the TXD of 89C51 respectively, RE, DE pin all are connected with the T0 of 89C51, and A, the B pin of A, B pin and communication interface (14) join; Be connected on the communication interface (14) of PC one end, through level transferring chip MAX232 level is become 0 to 5V from ± 12V by PC serial port RS232, remove R, D, RE, the DE pin of drive controlling 485 devices again by MAX232, reach balanced type Long-distance Control (twisted-pair feeder can reach 1000 meters), as shown in Figure 3.Link to each other with 485 buses between communication interface (13) and (14).

Receiving end (4) adds infrared filter (9) by CCD camera (8) and forms, that the camera in the present embodiment (8) adopts is the CCD camera VISTA of common black and white adjustable focus, the high speed acquisition equipment that connects (5) adopts is that model is the outsourcing device of FLY VIDEO II, it is inserted in the slot of PC (6); PC (6) generally requires the above internal memory of 64M, more than the dominant frequency 350MHz, and WIN98 operating system.

Use when detecting, running program as shown in Figure 4;

Initialisation image collecting device at first, behind the memory buffer, under smokeless state, by PC (6) by the RS232 mouth, send startup command to microcontroller (10) through communication interface (3), control circuit (2) is opened infrared light emissive source (1), light signal arrives infrared filter (9), enters CCD camera (8) through excessive space, 100～256 width of cloth figure are in PC (6) for process high-speed collection card (5) synchronous acquisition, adopt the method for coherent filtering to handle, be about to consecutive frame and add up, eliminate The noise; And formation circuit controls;

Obtain the initial smokeless infrared figure that receives through filter plate by the CCD camera;

The software that the flow process that employing provides according to flow chart 4 in the present embodiment is worked out is found out each maximal value in bright spot district of being separated by, and is stored this X, Y coordinate and gray-scale value; The corresponding bright spot district of each diode obtains the typical value of the peak value in each bright spot district as diode, and the mean value of common background signal; Obtain 10 * 12 smokescope value altogether, and the concentration value of storing these 10 * 12 points is gray-scale value and X, the Y coordinate figure; PC deposit in the figure to each bright spot district of finding bright image vegetarian refreshments around time spot zone zero clearing, prevent to disturb the bright image vegetarian refreshments of looking for next bright spot district; Successively this operation is done in each bright spot district, till having looked for 10 * 12 bright spot districts;

Having under the cigarette state, the current gray level value that each point was found in monitoring just now adopts same coherent filtering method to carry out denoising again;

Ask the relative smokescope value of 10 * 12 bright spots, and adopt scientific visualization graphics software IDL to draw out current relative smokescope image according to its coordinate;

If several different relative smokescope images constantly then repeat repeatedly to gather denoising, can draw out the time dependent dynamic relative concentration image of smog; Otherwise termination.

The disposal route that described employing coherent filtering method denoising detects is to utilize consecutive frame integral mean filtering method.In the ideal case, steadily the circulation autocorrelation function of white noise sequence on a certain cycle frequency α is zero, therefore for the signal with cyclostationarity, utilizes the circulation autocorrelation function to replace traditional autocorrelation function, can effectively suppress noise.But in practical matter, because data length is limited, the estimator of noise circulation autocorrelation function is also non-vanishing, therefore will influence the performance of cyclo-stationary method.Consider that in the present invention it is approximate static that the smog variation of being observed is compared with image acquisition speed, utilize the filtering of consecutive frame integral mean so be well suited for, this is that other smoke monitoring detectors are unexistent.Experiment shows that the result of this method gained also is goodish.

Under the meaning of circular correlation, owing to only consider a circular dependency on cycle frequency α, so signal to noise ratio (S/N ratio) should be defined as the ratio of signal and the power of noise in certain α section, promptly $R_{{\mathrm{SN}}^{\mathrm{\α}}}=\left|\frac{{\∫S}_s^{\mathrm{\α}}\left(f\right)\mathrm{df}}{S_w^{\mathrm{\α}}\left(f\right)\mathrm{df}}\right|=\left|\frac{R_s^{\mathrm{\α}}\left(O\right)}{R_w^{\mathrm{\α}}\left(O\right)}\right|$

Obviously, R _w ^α(O) more little, the circulation signal to noise ratio (S/N ratio) Just high more.Ideally, go up the circular correlation function R of steady random noise w (t) at the cycle frequency α of signal S (t) _w ^α(τ)=0 couple any τ all sets up,, at this moment And in actual applications, because calculating is finite length sequence, data length N can not unrestrictedly extend, and presses down the ability direct ratio so we use the noise of consecutive frame average filter method result circular correlation function

For example, during N=100 among the embodiment, Signal to noise ratio (S/N ratio) has improved 10 times.

The present invention adopts the data processing method of coherent filtering, has removed noise, and signal to noise ratio (S/N ratio) has been improved an order of magnitude, has improved the precision of measuring, and is not only to set a threshold values, and can obtains continuous relative smokescope value.

The present invention can certainly be to setting alarming threshold value in the one or more ranges of linearity in the diode dot matrix, in case smokescope reaches setting value and just thinks fire has taken place, begin to report to the police, and can monitor the Changing Pattern of having a few the smokescope figure of forming in the array simultaneously, can be used for the measurement and the fire detecting and alarm of multiple spot smog relative concentration.

Claims (2)

1, a kind of smog relative concentration image detector is characterized in that comprising infrared light emissive source (1), transmitting terminal control circuit (2), communication interface (3), receiving end (4), high speed acquisition equipment (5) and PC treatment facility (6) composition; Described infrared light emissive source (1) is that every row are connected in series the back, are total to n * m matrix plane that the m row are also formed together by n infrarede emitting diode (7), places on the end wall surface of large space; Described receiving end (4) adopts the CCD camera (8) that is provided with infrared filter (9), is connected to PC (6) through high-speed collection card (5); Make camera (8) and the filter plate (9) of the silicon plane parallel of each light emitting diode (7) on infrared light emissive source (1) matrix plane, form aspectant emission and reception in receiving end (4); Described transmitting terminal control circuit (2) comprises microcontroller (10) and 2 * m injectron (11) and 2 * m current-limiting resistance (12) composition; Anodal termination+50V power supply, negative terminal that infrared light emissive source (1) is gone up each row serial connection diode join by the current-limiting resistance (12) in interface J26 and the transmitting terminal control circuit (2), the drain electrode of another termination injectron (11) of current-limiting resistance (12), the source ground of injectron (11), grid are connected to the I/O mouth of microcontroller (10) P0～P2 respectively; Described communication interface (3) is divided into (13) and (14) two parts: communication interface (13) and microcontroller (10) at control circuit (2) one ends join, socket J25 with the serial port RS232 of PC (6) joins at the communication interface (14) of PC one end, and is continuous with 485 buses between communication interface (13) and (14).

2, a kind of smog relative concentration image detection method is characterized in that adopting following steps:

At first under smokeless state, by PC by serial port RS232 mouth, send startup command to microcontroller (10) through communication interface (3), control circuit (2) is opened n * m matrix plane infrared light emissive source (1) that every row are connected in series the back, are total to the m row and form together by n infrarede emitting diode (7), light signal arrives infrared filter (9), enters CCD camera (8) through excessive space, collect in the PC (6) through high-speed collection card (5), form the infrared image of CCD; Infrared figure is adopted the method for coherent filtering, be about to consecutive frame and add up, find out the maximal value in each bright spot district that is separated by in the infrared figure, store this X, Y coordinate and gray-scale value, and PC deposit the bright image vegetarian refreshments in the bright spot district that in the figure each found around time spot zone zero clearing; Successively this operation is done in each bright spot district, up to having looked for till n * m;

Having under the cigarette state, the current gray level value that each point was found in monitoring just now adopts same coherent filtering method to carry out denoising again; Ask the relative smokescope value of n * m bright spot, and draw out current smog image according to its coordinate; Repeat repeatedly to gather denoising, can draw out the time dependent dynamic relative concentration image of smog.

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