FR2643173A1 - Automatic detector of break-in or fire at great distance - Google Patents

Abstract

The invention relates to the optoelectronic apparatus capable of detecting the thermal radiation emanating from a fire, in particular from a forest fire, or the presence of an intruder on the site to be monitored, discrimination being done automatically by the variation in the location of the source, the variation of its intensity or, as far as fires are concerned, by the spectral behaviour of the flames, of their smoke and the oscillations which are peculiar to them. There are a great many apparatuses for protection or detection of fires, based on the mobility of the hot target, resulting in a modulation of the infrared radiation, either by grids, prisms, multi-directional mirrors or oscillating-mirror scanners. The present invention, differing from the already existing systems, due to the optoelectronic apparatus in its entirety being rotatable about the vertical axis in the manner of a radar, seeks the hot points, stops on the latter when they pass through a preset threshold, and carries out the analysis of this hot radiation over several physical parameters, characterising the presence of an intruder, fire or other thermal event. The apparatus according to the invention, after having marked and identified a suspect "target", automatically gives the alert by cable or radio and may transmit the image of the event via a matrix infrared detector forming part of the invention.

Description

 The present invention relates to a device, having the optics pre-coupled with the infrared sensors, the latter actuating the electronic analog and subsequently software, making it possible to compensate in time for forest fires or any other target emitting radiation. unwanted thermal effects in the field to be monitored.

 The inventor described the economic and ecological aspects of the forest fires which ravage the South of France and other countries with intense sunshine during dry periods, contained in his patent application N087 06592, dated May 5, 87.

 The present invention stems from the need to be able to detect incipient fires, at an early stage, when human watchers can hardly spot them by confusing them, for example, with morning mist or that of heat, this detection having to be carried out. do quickly so that the services of the firefighters can intervene in time before the brassier takes on a scale that is difficult to control. The device is designed to be autonomous, refueling with electricity by a solar panel and a battery-rechargeable battery, During the night. carrying out all the operations of detection of interpretation, analysis and storage of the information thus automatically prepared, which can transmit after the alarm is triggered, to the Post (PC of the fire department, Competent Service) the data on nature of the hot "target" detects, the cartographic positioning, the intensity and the composition of the fire, and on request transforms into an imagery receiver putting into service a multicellular matrix detector, sensitive to infrared radiation and capable of reconstructing by multiplexing action digi talised the image of the detected thermal event.

 This same device, according to the invention, having modified opto-electronic circuits, responding only to much weaker energetics, would be capable of detecting mobile thermal sources, such as men in the field to be protected, and being able to discriminate them, by software analysis of imagery, other mobile sources, such as animals in the field and tC

Numerous devices, existing on the market or those, being in the experimental stage, - are either fixed devices, with a wide receptive angle, such as anti-intrusion or anti-theft devices, or rotary devices scanning (scanners), crossing a thermal "target" very quickly, which requires a very rapid response (of the order of 10-3 sec) from the infrared detector, this fugasse crossing from a hot spot actually prevents from preceding has a further analysis of this incident thermal.

 The automatic detector device of the exothermic points on the ground to be protected, according to the invention, in a fixed base, which can be mounted on a mat in suitable height, this base being stationary, transmits the rotation to the opto-electronic part of the device sitting on an axis and able to rotate back and forth in rotation of 3500 complete or a determined angular segment. This sense of alternative rotation is dictated by the need to transmit multiple cables to the fixed parts of the device, such as at the base, the solar panel, the batteries, transmitter station, etc., which avoids the use of moving contacts, subject to corrosion, and resulting disturbances.

 In its general design, the apparatus according to the invention is illustrated chematically salt. Fig.1, therefore consisting, as indicated, of the fixed base (1) and the upper part (2), movable around an axis (X-X).

The fixed part of the device contains the electric motor and the mechanical reduction part (3 and 4) transmitting to the mobile part (2) by all suitable means, a constant and fluid rotation at a desired speed, p.

ex. for a revolution of 3603 in 30 sec. This fixed base, not being limited in size, can contain a large part of the electronics, software, analysis and storage, the transceiver transmission station (5) and others organs of the electrical power supply, (6), of stabilization (7) of information and imagery management (8) just like the organs of self-protection (9).

 The mobile part of the device (2), will have a window (10) transmitting the infrared (eg suitable plastic sheet, protected by deviating by an ara-solieil (11) a metal grid (12) protecting the entry of the device against birds and rodents, debt even grid acting as a Faraday cage against the penetration of parasitic waves, electric discharges etc. Inside this mobile box, will be placed the collimator (13) of parabolic preference, but in case the manufacturers of Frésnel lenses will make these plastic lenses with sufficiently precise optical resolution (eg 0.04mm), the invention provides for the placement of such a lens in place of the window ( 10) in this case, the infrared detectors (14-15) are placed in the focal space (y-y '). The placement of the collimator (13) with a parabolic concave mirror or the like, will be made against the naroi do box (2) so as to be able to adjust the outside axially (17).

 This mobile part (box 2), will contain in addition to the optics and detectors on the unoccupied parts of the box (against internal walls, electronic detection circuits, amplifiers, discriminators (19) multivibrators of shutter (chopping), the multiplexers and the converters, in particular, A / 'and of any processing of the received signal. In this box, outside the optical beam (18), will find a matrix multicell detector, or CCD-infrared, (19), including the flat or correct tilting mirror, allowing the call, to deflect the optical beam (18 ') on this image detector, which will be placed on the focal plane (zz) of the beam (18') thus deflected.

After having briefly listed the main content of the two parts of the apparatus, object of the invention, it is necessary to explain its principle operation: The mobile part of the apparatus (2) rotating around the horizon , captures the radiation from the site with a broad vertical band (Fig. 20) since the infrared sensor (14) has a threadlike vertical receiving surface, therefore the symbolic lens (13) representing either the collimator) concave mirror. or the Fresnel flat lens, transmits only the IR flux, emanating from a rectangle (20), the height of which covers a thin section of the site, from the horizon, up to the proximity of 100 mtr from the device. If the width "a" of the IR sensor strip (14) is p. ex. of 0.5mm, and the focal length of the optics is 150mm, such a detector, salt. the invention will cover 10 km from
distance a detectable field width of 33.3 mtr: it therefore suffices that over this "opening" width of the IR sensor appears a brazier, whose overall eise power, attenuated by atmospheric absorption corresponds to or is greater than the minimum detection threshold of l 'device, and clearly exceeds the noise inherent in electronics, that this thermal "signal" will be discriminated by @@@ reil.

Thus, assuming that a small fire 5 mtr in width from Garrigue or
brush rises flames and hot gases (especially steam and C02) to
5 mtr in height, and that the average temperature of this brazier is 8006 C.

At the emissivity coefficient of e = 0.5, such a focus, 10 km away, will radiate thermal power, including the average flux at the level of the device.
reil-detector will be 4.75.10-7Watt / cm2. A collimator of # 150 mm will center this flux on the receiving strip of the detector of 1mm2 of absorbent surface at the location (height) of this focusing, this flux will however suffer losses of the order of 65% due to the passage through the IR window and
the detector filter. The radiant power of 8.4.î0-5We 0.25 = 2.1.10-5
Watts. And given that the IR sensor, according to the invention has a responsiveness for the shutter time of 3-10-3 sec of 163 V / Watt, such a detector will give a signal of 3.4 mVolts; this summary calculation against, that, even having continuous scanning, as the patent of the undersigned N 87 06592 provides,
it is possible to easily capture the exothérmies located on the horizon, in -core that the background noise of the site (background-noise) can in certain conditions approach appreciably at this level. To avoid such an inconvenience, the invention present plans to stop the scanning of the mobile part of the device (2) on the hottest point on the site (by the same self-monitoring mechanisms, as the radios with automatic search of stations, stop the selector organ on the carrier wave Strongest TSF).

 Therefore, the optics (13) of the device being pointed at the point of the hottest exotherm, the invention provides the process of further analysis of IR radiation from such a source. For such an analysis, the filiform IR sensor (14), receiving different field radiations, contained in the receiving fringe, would be unsuitable. Here, according to the invention, two point sensors come into play, having the active surface of 1 mm 2 each, these two sensors being integral (15 and 16) with FIG. 30.

and can move vertically by a rack, (e1), moved by a suitable servomotor, (5) the latter, being electronically controlled, also, to stop in the same way on the most " hot "of the vertical axis. The positions of these two stops, in particular of the rotation of the optics (2) and these detectors (15 and 16) on the vertical axis, are represented by the optoelectronic or magnetic pulse counters (Hall changers). ) or by any other means of position counting, these data, transmitted to the PC allow the location of the event on the map, both on the cartographic map, and of approximate distance, given by the vertical angle with respect to l horizontal axis. This IR sensor (15), the role of which is to locate the exotherm on a vertical plane, is subsequently used to analyze the evolution of "hot" radiation over time. If the intensity of this thermal radiation is immutable, it can only be here particularly hot fixed objects. The blaze of a fire, in fact, causes the turbulent rise of very hot air and smoke (CO, C02, H20 ash and carbon), scrolling from bottom to top in bundles of very uneven intensity having the frequency from 0.2 to 5 seconds. The signal, supplied by the IR sensor, with an oscillating character, represents the fire criterion and can be interpreted as such by the software discrimination system.

 The role of the second IR sensor (16) fitted with a window with a large spectral bandwidth is to determine the spectral content of the hot gases. Given the momentary immobility of the sensor (15), it is therefore necessary to modulate the incident IR radiation by a chopper at the most appropriate frequency.

The chopper, according to the invention, carries two filtered selective bandwidth for gases, and dominant vapors for forest fires, p. ex. C02 and H2O, note here, that the invention includes the displacement of the spectraede fringe of the emissivity of a gas exited by the high temperature, and the emp- law of "selective" filters copmte held this displacement : thus, e.g. the delight of the COO. whose atmosphere absorbs totally at 294 K on the emissivity @ = 0.9 on the spectral fringe of X = 4.64 µm, on which the atmospheric absorption at 294 K is only 0.029. saturated with water, this displacement is even more blatant, still the vapor containing the solid particles of soot and ash, acts as a quasisolid screen at cost. of radiation of @ = 0.93 and 0.99 while the atmosphere at 294 K at relative humidity of 70 to 85% rel. is almost transparent. for the spectral band between 6.9 and 12 m. . The chopper, of whatever embodiment, represented in Fig 4 by eg a mobile frame (24) alternately moving 8 selective filters, separated by an opaque plate: in the extreme position p. ex. the filter 25 is placed at the input of the sensor (16), then, in the middle position, the opacity (25) and at the other end another selective filter (27). The two pieces of information, p. ex. on the content of
Hot C02, steam, or vegetable resins contained in the smoke, will be picked in phase, compared to the reference signal, middle position of (26), and and analyzed by the software after adequate amplification by the integrated amplifier with narrow bandwidth, corresponding to the chopping frequency.

 When these two detectors (15 and 16) give the positive response (ie presence of intensity oscillations, presence of hot gases) the software system, give the alert, indicating by appropriate coding the position, l evolution and spectral content of the exotherm thus identified and analyzed.

 This stop of rotation of the device (2), will only last for 4 to 7 sec, after the alert, the device will resume to its rotation, the hot spot of the site previously spotted, will however be erased for a determined period of time, so as not to cause the stop and successive at each rotation at this same point, already identified.

 The infrared sensors, used for this purpose, can be the same, already described in the undersigned's patent under the N 87 06592 or else of the new generation, so far far the subject of a future patent application. It is to be stipulated here, that the sensors (14 and 15) acting without reference chopper, and exposed to variable IR radiation from the site, during rotation, can generate important signals, when their temperature is very different from that of the site, which can result in untimely alerts. To remedy this drawback, the invention provides for placing on the base of these sensors or any other IR sensors used, refrigerant Pelltièr elements, automatically reducing the temperatures of the IR sensors and keeping them at the optimum level. the cooling or heating action, according to the need) will be controlled by software having the function of maintaining the average signal, by integration, on a minimum threshold compared to the ambient temperature in the box (2) and the average temperature of the site .

When the fire alert is given, by cable or TSF, we can, on request-return, trigger the imagery retransmission mechanism, for this purpose, the plane mirror where slightly conve @@ e (extending the focal distance ) folds down (fig. 5 (28) deflecting the IR beam which is suitable for an infrared CCD: the latter (29), being made up of 10,000 reticles, accumulates during a fraction of a second the thermal image and the rapid multipliers pick up l thermal image as el-static charges on reticles by restoring the image on the LCD screen or other to the PC of
Sap.-Pompièrs. Since the retransmitted image is stationary, the retransmission of the "image" elements can be done at a relatively slow rate, compatible with the width of the passband of the frequencies on cable or TSF. The imagery retransmission can be followed every 2 sec. e.g.

The detector for locating and signaling the human presence on the ground to be monitored (borders, military bases, airports, etc.) according to the present invention will be of smaller dimensions (possibility of camouflage), and the additional detection members such as the sensors
Analytical IR (a5 and 16) no longer having any reason for being, will be deleted.

On the other hand, the filiform detector with large vertical detection angle will be maintained, and duplicate the filiform, place side by side, preferably in the same salt box. Fig 6 (30). The first strip of this filiform sensor (14 ′) has a surface sensitized to infrared by an adequate absorbent layer being electrically conductive or split with a thin conductive layer,. This sensor therefore forms a single bi-pole constituted, as a capacitor of the two metallizations throughout the strip and of a very thin thickness of a semiconductor, PVDF, pyrocapacitive substance (eg TiO2) or PVTF of the new generation.

This strip (14) stretched by a spring (31) and supported by threads or other supports made of nylon or foam with very low thermal conductivity, (32). Whatever the height of the incidence of the infrared beam, this detector translates the heat into a variation in resistance, polarization voltage or, capacitance or any other parameter translatable into an electrical signal. The second strip (33), vertical and parallel to the first, 0.5 to 2mm apart, is identical to that- except that one of the metallizations, on the rear side, eg has separations which make this strip represent p . ex 16 autonomous sensors (34), which can be connected to the preamplifier by a multiplexer: these 16 links (35) will be interleaved first, and this second IR sensor will be identical to the first (14) by separating the "pickels" we obtained an array.

 The device. intrusion detection, exploring the site from its rotating part, will be adjusted and sensitized in such a way that when the optics picks up thermal radiation clearly detaching themselves from the temperature of the environment, the rotation mechanism, controlled by the sinal detaching itself from the. site temperature, will stop, keeping the target hot between the two filiform strips of the detector; the appearance of heat on a strip will cause the mechanism to reverse, the rotation will now oscillate the hot point between the two sensors. If this hot point changes its position, the optics thus enslaved will follow it in its evolutions on field. during this time (q-that seconds) the multiplexer interrogating the areas (34) of the second strip, will determine on which retucule is exposed to the heat coming from the target, and thus determine its approximate distance.

 es three factors, being confirmed, in particular, 1 the presence of a hot spot on the ground, 2. its mobility, and 3. its approximate distance from the device, the electronics will trigger the alert, and if necessary , the thermal beam coming from the collimator, will deflect by the interposition of the mirror (28) Fig. 5, thus focusing the thermal image on the infrared CCD, described previously. The exploration of the image, can be done electronically by software processing, and can lead to the distinction of the contours, making it possible to distinguish - whether it is the human presence on the ground or an animal .

Using a high definition and resolution parabolic collimator of 0.02mm, 120mm in diameter and 150mm focal length, the man, dressed normally at 32 C average temperature. detaching from the background of 220C, will produce on the focal plane of the optics a hot spot acting on the sensor
IR (14). If its distance from the device is 150 mtr, its radiant surface of 6 # 103cm2 having @ = 0.7 @ the optics of the device will receive a thermal flux of intensity of 3.4.10-8 W / cm2.The collimator having the surface of 113 cm
concentrate this flux on a tiny point on the filiform detector (14), the energy captured and concentrated will therefore be 3.8.10-6 Watt, lessened by the passage of the filter (36) fig.6 - having a spectral bandwidth of 7 at
12 m, centered on 10.6um, 55%,; this energy of 1.7.10-6Watt will generate on the sensor (14) at 2 Hz of the oscillation frequency, a useful signal of 320 Volts: this signal, detaching itself from the noise of the 0.02 V detector, will be perfectly operable. Adding the noises
inherent in the amplification and processing of the signal, being able to reach the picks of 60 V, this signal will be perfectly usable both to ensure the turning of the optical system, on this target, that to trigger the alert or to ensure the readability of the imagery by CCD-IR.

On the whole, this system, according to the present invention, both for effective detection of intrusion and of long-range fire, is, in its software part, managed to store the information received by the infrared radiation from the site. , and to manage them intelligently by the appropriate microprocessor: overall, these operations consist in carrying out permanently, circular or angular sweeping movements of the zone to be monitored, each information on detected heat sources located on the site, are automatically compared with information stored by the previous route, relating to known heat sources and not to be taken into account, thus determining the newly appeared heat sources, leading to the triggering of an alert, when these new sources, by in-depth analysis of mobility, oscillated
ticn or of the combustion gas content, give the certainty of a fire event or of the human presence on the ground. For the detection of the human presence at long distance (e.g. up to 1 km and In addition, the invention provides for the use of photodetector layers with Mercury-Selenium Telluride (HgCdTe), which, suitably treated, demonstrate, even at relatively low cooling by Pelletier thermobatteries,
sensitivity around 10 m sufficient and extremely fast response time, allowing to accelerate the scanning and alerting process.

 Like all devices with the same purpose, the salt detector. 1 the invention, being very compact and relatively light, can be placed either on a watchtower or in the semmet of a mesh mat having the height exceeding the treetops, which can go from 15 to 35 m, this mat , comprising in the middle part the solar panels, the charge and supply monitor, and the self-protection instruments, such as the passive approach detector, the vibration detector, as well as the smoke detector (celà, to counter the fires with the foot of the apparatus). The transceiver devices with automatic start-up will be associated with the detector device and the self-protection devices. This autotransmission system by the TSF or cable wave, will thus be able to signal to the PC of the services concerned just as well the presence of an exothermic target on the ground to be monitored; that in the event of an attempt to sabotage such an installation, the nature of such an attempt (smoke, approach within the grill of a subject, suspect vibration).

 It is understood that the present invention has only been described and shown by way of example and that any technical equivalence could be made in its constituent elements without departing from the scope of the present invention which is delimited in the ancillary claims. Fig.6 shows schematically the steps of the detec -tion according to the programming specific to the present invention.

In the foregoing, the organs essential to the achievement of
the present invention, referring to the drawing board I / I, presented
in the most simplistic way, have been commented very briefly. For
understanding, let us say, that the construction details, salt.

 Fig. 1, are only examples of one of the possible embodiments.

The lower part, the base, carries a tubular axis in the middle,
not digitized, rotating on two ball bearings, on the tip
of this axis is the mobile unit (2), all the electrical connections
triques between (1) and (2) pass through the interior of this axis, as
q - a braided or twisted multi-strand cable, to support in the long run
the rotation. The rotation will be done by a toothed pulley of the motor (3-4),
resulting in a nylon flout, eg with internal toothing, fixed on
the tubular part of the housing (2). The filiform sensor (14) and the
two vertical scanning sensors (15-16), are integral with the
collimator (13), just like the tilting reflector (28).
detector, looking for the hot spot on the vertical plane of the focal plane, -it can have two thermosensitive strips horizontally, connected
p. ex. in polarization opposition, when the servomotor "s" (Fig.3)
by rotation of the threaded rod raises the rack (21), up to
alignment of the sensor (15) with the hot spot, this detector will
signal, by two signals of opposite polarity, the alternating rotation of the
motor, maintaining the "hot spot" between the two strips of the sensor.

 The analytical sensor for smoke gas content (16).

-fixed below (15), includes a periodic shutter grabber
(24), illustrated seen from above in fig. 4 and in perspective, salt. Fig. 5
This electromagnetic, periodic or aperiodic chopper
that, piezoelectric, with PVDF in bi-blade, or with mobile frame relates to the
oscillating rod one or more selective filters for the discrimination
gases, the densest in the smoke from the fire, eg CO2
and steam. To spot these weak signals, a reference
will be ensured, by interposition, between the filters (27 and 25) of a
opaque plate (25}, reducing the sensor signal (16) to zero.
position of the choppeur will control the action of the Pelltièr element, not
indicates, whose role is to heat or cool the sensor (s),
to minimize the "background noise" zero signal.

The overall functioning of the device is shematized on the organi-
gram salt. Fig. 7: The solar generator "G" acting in parallel before.

the accumulator "H" and controlled by the monitor "I" feeds 4 networks of 1 '
power supply: servomotors "K", electronics "L", chopper "tl"
and cooling Pelltièr "N", conducted to the base (1) by IV. The
optical head of the device (2), effecting horizontal rotation, when
it meets the hot spot, compares the thermal signal A with the relief
thermal of the previously memorized site (B). When the signal "A" differs
fère considerably of the "B", the aiming stops on this hot point "C", and
programming of automatic analysis between games. The servomotor (s)
mount the two detectors on this hot spot (D) and the sensor 15 stop
on this point gives its position to the microprocessor "O" by the channel "I".
position of the optical axis of the sight (2) as the height of the (15)
will be done by impulse opto-electronic or magnetic (Hall) reading,
or each pulse corresponds p. ex. an angular. This same detector (15)
at standstill, samples the oscillation of the hot spot, each brazier, in fact,
oscillates in intensity between 0.2 and 8 Hz. This information, just like the evo-
global exothérmie lution is transmitted by network II to the microprocessor (0).

Similarly, the gas content result explored by the sensor 16 is conveyed
by (III) to the software (O). The complete analysis of the information is done
on terminal "P", in the event of a "positive" result in the transmitted alarm (Q)
by this transceiver station on the antenna, at the top of the mat.

Claims (3)

 1 / Device for automatic detection of heat sources, particularly forest fires, and for a modified version, of the presence of intruders in an area to be monitored and this at a great distance, characterized in that it includes an optic high resolution (13) and infrared sensors 14-15-16) with appropriate spectral bandwidth, placed in the focal space of the said optic. The assembly thus formed, rotates around a vertical axis following the horizon, scanning due to a wide vertical angular opening of one of these sensors (14), a large vertical segment of the terrain to be monitored (from the horizon up to about 100m from the foot of the detection device), and when a significant thermal radiation will be on this scanning path, the electrical signal generated thereby by the detector (14), will spontaneously stop the rotation, The detection device points at this hot spot, other detectors with a receiving surface more reduced rices (15-16) which will intercept, thanks to a servomotor "s", this hot spot, therefore these detectors automatically analyze the oscillations proper to the braziers of progression, radiation intensity, the characteristic gas content of. combustion of plants and if these parameters prove to be suspect Ae Detection device triggered by TSF system, or modems, position of the event, its characteristics (intensity, gas content), then folding down a deflector mirror (28 ) projects the radiation received on an infrared CCD, the thermal image thus generated is transmitted to the PC of the departments concerned.  21 Detection device according to claim 1 characterized in that for the detection of intruders in the field the infrared sensor (14) consists of two filiform strips (14 'and 14 ") preferably pyroelectric, very thin in width , covering a wide angle on the vertical plane, one of these strips is subdivided into a useful number of autonomous detector pads, allowing, by multiplexing, to locate the hot target on the vertical plane (distance), the two strips are very close together l one from the other, the processing software and the associated electronics allow the servomotor to stop the detection device in its optical axis on the hot target and to continue it in case of displacement of the latter on the ground at monitor.  31 Detection device according to claim 1 claim 2 characterized in that, after locating the hot spot on the horizontal plane in the field to monitor the second filiform strip (14 ') which is subdivided into a number of autonomous plates ( 33) comes into action and an electronic switch (multiple) interrogates each of these plates (35), finds the one heated by the target, and informs the PC of the position of the hot target on the ground.  4 Detection device according to any one of the preceding claims, characterized in that the vertical positioning sensor (14) contains one or two filiform strips, sensitive to infrared radiation, the detection device performs a rotation scanning the horizon about 100m from the base of the detection device and placed in the focal plane of the collimator (13) this assembly stops when the hot spot is identified by one or two strips of the detector (14), one kings the device stopped. couple of detectors (15-16), comes into action, moving on this hot point, driven by a servomotor, analyzes the event. One of these detectors examines the oscillatory effect of the alleged brazier, also integrating the growth The other (16), fitted with filters, performs the spectrophotometric analysis of hot gases or smoke, it is only if these three criteria confirm that the event is due to one fire source, that the electronic reception and information processing system triggers the alert signal.  51 Detection device according to any one of the preceding claims, characterized in that:  a / That the detector (16) called to perform the spectrophotometric analysis of the hot gases will preferably be of the photonic type (such as a lead selenide photodetector-PbSe- or -HgCdTe- cooled by Pelletier cryostats).  b / That the appropriate filters (25-27) having an opaque space (26) will act as a chopper will modulate the received signal  6f Detection device according to any one of the pre-sales claims, characterized in that:  a / That a single poisitioning sensor (16) will be used both for the analysis of the oscillatory effect, of the growth of the emitted infrared intensity, and for the analysis of gases.  b / That the filters (25-27) tuned to the spectral frequency characteristic of the most significant hot 3az of a fire.  These two bridges ab) thus facilitate the discrimination of a real fire from any other parasitic radiation, the chopper cutting the radiation in phase with the pass frequency of the amplifier "D", such discrimination in phase with the position of the respective one makes it possible to analyze several components of the gases separately  7 / A detection device according to any one of the preceding claims, characterized in that the automatic positioning of the optical axis of the sensors The infrared on the heat source is associated with the pulse counting of position, this information after being memorized, will be retransmitted during the alarm, just like The other parameters of the fire or of the presence of the intruder on the ground, to the PC concerned.  8 / Detection device according to any one of the preceding claims, characterized in that the detector (s) after their automatic positioning on a particularly hot source, different from the hot zones recorded during previous scans, the signal emitted by the detector (s) will be subjected to electronic analysis, if this analysis shows that the oscillations in intensity due to the turbulence of fiammes (hot gases or fumes) is a global growth of the emitted intensity, these data will also be recorded and memorized by the The logidel treatment unit, used in conjunction with the content of typical combustion gases, to discriminate between the fire and the triggering of the alarm.  9S i> detection ispositff according to any one of the preceding claims, characterized in that the automatic positioning detector (s) (servomotor on the hot source, fire or human presence), in the vertical axis, (ie the detector (14 ) with two heat-sensitive filiform lamellae (14 'and 14 "), at least one of which is subdivided into any number of autonomous pixcels (33)), i.e. the punctual detector (15 or 16) moving by an endless screw ( 21) actuated by a servomotor "s", the position of this or these detectors being focused on the thermal event, identify by digital coupling (preferably digitalized) this digital information of the cartographic position of the source of hot radiation will be used for controlling the degree of amplification of the signal generated by the detector (s), because, in reality, the position of the near exothermic event, horizontally, corresponds to distant sources. (n cessitant maximum amplification). The position under a significant vertical angle, on the other hand, means that the event is near and requires only a small amplification.