EP0705469A1 - Device for detecting an intruder in a building or vehicle by infrasonic and/or pressure wave detection and method for so detecting an intruder - Google Patents

Device for detecting an intruder in a building or vehicle by infrasonic and/or pressure wave detection and method for so detecting an intruder

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Publication number
EP0705469A1
EP0705469A1 EP94926262A EP94926262A EP0705469A1 EP 0705469 A1 EP0705469 A1 EP 0705469A1 EP 94926262 A EP94926262 A EP 94926262A EP 94926262 A EP94926262 A EP 94926262A EP 0705469 A1 EP0705469 A1 EP 0705469A1
Authority
EP
European Patent Office
Prior art keywords
signal
building
infrasonic
sensor
threshold
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94926262A
Other languages
German (de)
French (fr)
Inventor
Raoul Rogari
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
A3P Sarl
Original Assignee
A3P Sarl
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by A3P Sarl filed Critical A3P Sarl
Publication of EP0705469A1 publication Critical patent/EP0705469A1/en
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B13/00—Burglar, theft or intruder alarms
    • G08B13/16—Actuation by interference with mechanical vibrations in air or other fluid
    • G08B13/1654—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems
    • G08B13/1681—Actuation by interference with mechanical vibrations in air or other fluid using passive vibration detection systems using infrasonic detecting means, e.g. a microphone operating below the audible frequency range

Definitions

  • the present invention relates to an intrusion detector in a building or a vehicle by detection of infrasound, and / or pressure waves as well as a method of intrusion detection in a building or a vehicle.
  • intrusion detectors There are two types of intrusion detectors currently known, volumetric sensors which detect events in the monitored volume, on the one hand, and perimeter sensors, which detect building openings to the outside, on the other. The first have the main flaw that they do not detect presence until after the intrusion, when it is already too late. The second are mainly made up of sensors placed on all the openings and connected by wired network to an alarm center. In the two types of detector presented above, a multitude of sensors must be used to effectively protect a building. Other types of detectors make it possible to limit the number of sensors: these are infrasonic detectors which have on the one hand the advantage of monitoring the entire building with a single sensor and on the other hand which react to intrusions as soon as 'they happen.
  • infrared intrusion detectors are very sensitive to infrasound of natural origin, for example generated by the action of wind or explosion, on flexible parts, windows, roofs, doors of the building, and therefore have a high error rate, i.e. they generate many false alarms.
  • the problem consists in the separation on the one hand of pressure waves and infrasound coming from events external to the building, which must be ignored, and on the other hand from pressure waves and infrasound coming from events internal to the building, which must be detected.
  • the invention intends to remedy this drawback by presenting a device comprising two infrared sensors placed respectively inside and outside the monitored volume and a means of comparing the signals emitted by said sensors.
  • the two sensors are connected, by wire or by radio to an electronic circuit which is adapted to detect the correspondence, including with an advance or a delay of a few fractions of a second, between infrasonic signals picked up by the two sensors, correspondence proving the external origin of these signals.
  • a signal picked up by the interior sensor and not corresponding to any external signal is considered as an intrusion and triggers an alarm, a telephone transmission, for example.
  • the device which is the subject of the present invention is thus a device for detecting intrusions into a building, characterized in that it comprises, on the one hand, an infrasonic sensor placed outside the building, on the other hand, an infrared sensor placed at inside the building, a means of dividing the absolute value of the amplitude of a signal from the indoor sensor onto the absolute value of the amplitude of a signal from the outdoor sensor and a signal from an integrator circuit integrating the average amplitude of the external sensor for a period of a few fractions of seconds thus ensuring automatic control of the sensitivity of the threshold crossing of a threshold circuit receiving the signal leaving the division means, a storage means crossing the said threshold, a means of measuring the time difference between the signals from the two sensors and a means of transmitting alarm signals connected to a firstly by means of storage and secondly by means of time offset measurement.
  • FIG. 2 represents an infrasonic sensor incorporated in the device presented in FIG. 1.
  • FIG. 3 represents a block diagram of an electronic circuit for comparing signals emitted by two sensors presented in FIG. 2.
  • FIG. 4 represents an electronic diagram of the circuit presented in FIG. 3.
  • FIG. 5 represents signals transmitted by elements of the circuit presented in FIG. 3.
  • FIG. 1 a building 1 comprising a door 2 and a window 3, an interior infrasonic sensor 4, an electronic comparison circuit 5 and an exterior infrasonic sensor 6 placed outside the building 1.
  • the building 1 is of any type but does not have a permanent natural opening, is relatively impermeable to drafts, has no walls or too flexible roofing.
  • Door 2 and window 3 are closed when the device is in the surveillance state and no intrusion takes place.
  • the interior infrasound sensor 4 is presented in FIG. 2. It is adapted to pick up ambient infrasound inside the building and to emit an electrical signal representative of the intensity of the infrasonic waves reaching it.
  • the exterior infrasound sensor 6 is presented in FIG. 2. It is adapted to pick up ambient infrasound outside the building and to emit an electrical signal approximately proportional to the intensity of the infrasonic waves reaching it.
  • the electronic comparison circuit 5 is presented in FIG. 3. It is connected on the one hand to the interior infrasonic sensor 4 and on the other hand to the exterior infrasonic sensor 6 and is adapted to compare the signals emitted by the infrasonic sensors 4 and 6.
  • the operating principle of the device is as follows: the threshold for detecting indoor infrasound is a function of the output of a means of dividing the absolute value of the amplitude of a signal from the indoor sensor onto the absolute value of the amplitude of a signal from the outdoor sensor and a signal from an integrator circuit integrating the average amplitude of the outdoor sensor for a period of a few fractions of seconds and the number of oscillations of the infrasonic wave exceeding a certain threshold. When this detection is obtained, an identical detection outside the building can cancel the effect.
  • infrasound moves much faster than pressure waves.
  • a pressure wave encounters a flexible obstacle, such as a door, window or roof, for example, it generates infrasound.
  • These infrasounds form an envelope of the initial pressure wave which is picked up with a time delay or delay in an identical manner by the exterior infrasonic sensor 6 and by the interior infrasonic sensor 4.
  • infrasound is emitted by the opening of a door or a window.
  • the comparison circuit 5 is first adapted to perform a division of the infrasonic intensity at
  • circuit 5 is adapted to transmit potential alarm information.
  • the signal coming from the external infrasonic sensor 6 is higher than another threshold during the few fractions of seconds following the emission of the potential alarm information, the potential alarm information is deactivated, a reactivation of this information alarm cannot be carried out for a period of the order of one second following deactivation.
  • the potential alarm information becomes an alarm signal only if the potential alarm information is not deactivated.
  • FIG. 2 represents an infrasonic sensor incorporated in the device presented in FIG. 1.
  • an infrasonic sensor 4 and an infrasonic sensor 6.
  • the infrasonic sensors 5 and 6 each include an environment 10, a capillary 11, a chamber resonance 12 and an acoustoelectric sensor 13.
  • the sensor 13 is placed in the resonance chamber 12 which is formed in the sensor and is in communication with the outside via the capillary 11, which is in the form of a tubular element of small diameter.
  • the environment 10 is the ambient air, either inside the building 1, for the indoor infrasonic sensor 4 or outside the building 1, for the external infrasonic sensor 6.
  • the capillary 11 makes a very narrow opening between the air present inside the resonance chamber 12 and the environment 10, and it has an internal diameter adapted to allow only the lower low frequencies to pass through. at twenty Hertz.
  • the resonance chamber 12 combined with the capillary 11 is adapted to resonate at the desired infrasonic frequencies.
  • the acoustoelectric sensor 3 is adapted to transform the infrasonic signal which reaches it inside the resonance chamber 12 into an electrical signal.
  • the acoustoelectric sensor 13 can consist of an electret effect microphone, for example. It should be noted that the shape of the resonance chamber 12 and, consequently, that of the infrasonic sensor 4, can be parallelipipedic, cylindrical or spherical.
  • FIG. 3 represents a block diagram of an electronic circuit for comparing signals emitted by two sensors presented in FIG. 2.
  • FIG. 3 In FIG. 3 are represented four infrasonic sensors 41, 42, 61 and 62, two bandpass filters and two amplifiers 15 and 16 connected respectively to the infrasonic sensors 41 and 42 on the one hand and to the infrasonic sensors 61 and 62 on the other hand, an analog-digital converter 23 and a digital-analog converter 24, a signal processing means 17, a sensitivity adjustment means 18, an alarm and display control means 20, an output relay d alarm 21 and a display 22.
  • the infrasonic sensors 41, 42, 61 and 62 are of the same type as that presented in FIG. 2.
  • the sensors 41, 42 and 61 are placed inside the building 1, the infrasonic sensors 41 and 42 being placed in the monitored room and the infrasonic sensor 61 being placed outside the monitored room.
  • the sensor 62 is placed outside the building 1.
  • the sensors 41 and 42 are used to measure the infrasound inside the building 1 and the sensors 61 and 62 are used to control the origin of infrasound present inside the building 1.
  • the infrasonic sensors 42 and 61 are not essential for the operation of the device but they make it possible to increase the control of the interior or exterior origin infrasound detected.
  • the two amplifiers 15 and 16 are of known type and are adapted to amplify the signal leaving the infrasonic sensors so that they provide the same signal for the same initial infrasonic.
  • the analog-to-digital converters 23 and digital-to-analog 24 are of known type and adapted to transmit respectively a digital signal and an analog signal representative respectively of the analog signal and of the digital signal which they receive from the amplifiers 15 and 16.
  • the signal processing means 17 is adapted to perform a transfer function between the data it receives and the data it transmits and, in particular, to perform a ratio of the amplitude of the signal coming from the internal infrasonic sensors 41 and 42 on the amplitude of the signal from the infrasonic sensors 61 and 62. It comprises a first circuit having a first threshold and providing potential alarm information as soon as the ratio is above the fixed threshold. This alarm information is canceled by a second circuit having a second threshold connected to the external infrasonic sensor 62, if said second threshold is exceeded for a given duration preceding or following the appearance of the potential alarm information.
  • the sensitivity adjustment means 18 is of known type and is suitable for controlling the value of the thresholds presented above.
  • the alarm control and display means 20 are adapted to cancel the potential alarm information and to send to the display 20 either a canceled potential alarm information signal or an information signal d 'potential alarm confirmed, depending on whether the cancellation has been made or not. It is also suitable for controlling the passing position of the alarm output relay 21 when the potential alarm information is not canceled.
  • the alarm output relay 21 is of known type and allows any type of electrical system to be connected to the device.
  • this alarm output relay 21 can be connected to an alarm center, to a telephone transmitter, to a siren, to a lighting of lamps, for example.
  • the display 22 is only intended for checking the correct operation of the device. It is of known type, for example consisting of a row of light-emitting diodes.
  • the analog-to-digital converter 23 is incorporated into the signal processing means 17 and converts the analog signals from the amplifiers 15 and 16 and from the digital-to-analog converter 24 into digital signals.
  • the digital-analog converter 24 is adapted to transform temporally into analog signals the digital signals which it receives from the signal processing means 17.
  • the means for processing the signals 17 leaving the infrasonic sensors 41, 42, 61 and 62 is combinatorial and sequential. Indeed, it combines the signals leaving the infrasonic sensors with signals leaving itself and includes time integrators.
  • FIG. 4 represents an electronic diagram of the circuit presented in FIG. 3.
  • a detection chain 29 comprising the internal infrasonic sensor 4, a resistance bridge 30, an adjustable amplifier 31, a bandpass filter 32, a chain amplifier 33 and a full-wave rectifier 34.
  • a control chain 39 comprising the external infrasonic sensor 6, a resistance bridge 40, an adjustable amplifier 64, a bandpass filter 65, a chain amplifier 43 and a rectifier 44.
  • the full-wave rectifier 34 is connected on the one hand to a first circuit at threshold 45, on the other hand to a first integrator 46 and again on the other hand to an analog-digital converter ratiometer 47.
  • the threshold circuit 45 is connected on the one hand to a first cycle counter 51, on the other hand to a standby and wake-up circuit 48 and again on the other hand to a second cycle counter 52.
  • the full-wave rectifier 44 is connected on the one hand to a second integrator 49 and on the other hand to the first integrator 46.
  • the first integrator 46 and second integrator 49 are connected to the inputs of an adder 50 whose output is connected to analog digital converter 47.
  • Analog digital converter 47 is connected to a second threshold circuit 53 itself connected to the first cycle counter 51, on the one hand, and to a first logic gate 54, on the other hand.
  • the first integrator 46 is connected at its inputs to a reference supply 55, to the full-wave rectifier 34, to the full-wave rectifier 44 and to a statistical integrator 56, and at its outputs to the summator 50, to the first logic gate 54 and to a second logic gate 57.
  • the standby and wake-up circuit 48 is connected to a power supply 58 of the decision means 59.
  • the first cycle counter 51 is connected at its output to a third threshold circuit 60, itself connected to a timer circuit 66, itself connected to an alarm output circuit 67.
  • the second cycle counter 52 is connected to a matrixing circuit 63, itself connected to the statistical integration circuit 56, itself connected to the second logic gate 57.
  • the logic gate 57 is finally connected to a reset input of the timing circuit 61.
  • the decision means 59 comprises the cycle counters 51 and 52, the logic gates 54 and 57, the circuit at threshold 60, the timing circuit 66, the alarm output circuit 67, the matrixing circuit 63 and the statistical integration circuit 56
  • the detection chain 29 is intended for shaping the signal leaving the internal infrasonic sensor 4.
  • the resistance bridge 30 is adjustable and adjusted either at installation time either by the user as a function of the effective position of the internal infrasonic sensor 4 so that it has an appropriate sensitivity.
  • the resistance bridge will be placed so as not to limit the amplitude of the signal leaving the internal infrasound sensor 4.
  • the adjustable amplifier 31 is, on the other hand, adjusted at the factory and can only be re-adjusted after changing the internal infrasonic sensor 4 or aging for several years.
  • the adjustable amplifier 31 is adjusted so that with a given position of the resistance bridge 30, the response of the assembly formed by the internal infrasonic sensor 4, the resistance bridge 30 and the adjustable amplifier 31 is normalized.
  • the bandpass filter 32 is of known type and is adapted to reduce the intensity of the electric signals coming from it from the adjustable amplifier 31 and having high frequencies or low frequencies, compared to the central resonance frequency of the chamber. acoustic 12 incorporated in the internal infrasonic sensor 4.
  • the chain amplifier 33 is of known type and suitable for correcting the dispersions of the components of the detection chain 29.
  • the full-wave rectifier 34 is of known type and is suitable for rectifying the signal leaving the chain amplifier 33.
  • the control chain 39 is intended for shaping the signal leaving the external infrasonic sensor 6.
  • the resistance bridge 40 is adjustable and adjusted either at the time of installation or by the user as a function of the effective position of the sensor external infrasonic 6 so that it has an appropriate sensitivity.
  • the adjustable amplifier 64 is factory set and can only be re-adjusted after changing the external infrasonic sensor 6 or aging for several years.
  • the adjustable amplifier 64 is adjusted in such a way that with a given position of the resistance bridge 40, the response of the assembly formed by the external infrasonic sensor 6, the resistance bridge 40 and the adjustable amplifier 64 is normalized.
  • the bandpass filter 65 is identical to the bandpass filter 32.
  • the chain amplifier 43 is of known type and suitable for correcting the dispersions of the components of the control chain 39.
  • the full-wave rectifier 44 is of known type and is suitable for rectifying the signal leaving the chain amplifier 43.
  • the rectifier 34 is connected on the one hand to a first threshold circuit 45, on the other hand to a first integrator 46 and also on the other hand to an analog-digital converter 47.
  • the first threshold circuit 45 is of known type and supplies a logic signal "1" when the signal leaving the full-wave rectifier 34 instantly exceeds a fixed threshold value.
  • the first integrator 46 has a very high time constant and therefore provides a signal varying slowly with respect to the frequency of the detected infrasonic waves.
  • the analog digital converter ratiometer 47 is of known type. Its reference voltage is supplied by the adder 50 and it is adapted to supply a digital signal proportional to the difference of the signal reaching it from the detection chain 29 and the reference voltage supplied by the adder 50.
  • the threshold circuit 45 is connected at its output on the one hand to a first cycle counter 51, on the other hand to a standby and wake-up circuit 48 and again on the other hand to a second cycle counter 52.
  • the threshold circuit 45 causes on the cycle counters 51 and 52 the authorization to count during a wake-up time.
  • the standby and wake-up circuit 48 is adapted to control the supply of power to the decision means 59 by the supply 58, to maintain this supply for a period of several seconds after the last logic signal "1" leaving the threshold circuit 45.
  • This arrangement has the advantage of saving energy and of maintaining an effective alarm in working condition even after being put on standby, that is to say a power cut by the standby and wake-up circuit 48, as well as outside the effective alarm state to prevent alarm triggers by parasitic logic signals or alarm output powers coming from the decision circuits 59.
  • the full wave rectifier 44 is connected on the one hand to a second integrator 49 and on the other hand to the first integrator 46.
  • the second integrator 49 has a time constant much less than the time constant of the first integrator 46 but greater than the pseudo period of the signal leaving the control chain 39.
  • the first integrator 46 and the second integrator 49 are connected to the inputs of an adder 50 whose output is connected to the analog-to-digital converter 47.
  • the adder 50 is of known type and is suitable for adding the signals coming from integrators 46 and 49.
  • the output of the analog digital converter 47 is connected to a second threshold circuit 53.
  • the second threshold circuit 53 is of known type and provides a logic signal "1" when the signal leaving the analog digital converter 47 exceeds an adjustable threshold, by encoder wheel, for example.
  • the output of the second threshold circuit 53 is connected to the first cycle counter 51, on the one hand, and to a first logic gate 54, on the other hand.
  • the first integrator 46 is connected at its inputs to a reference supply 55, to the full wave rectifier 34, to the full wave rectifier 44 and to the statistical integrator 56, and at its outputs to the summator 50, to the first logic gate 54 and at the second logic gate 57.
  • the reference supply 55 consists of the half voltage of the supply to the device.
  • the first cycle counter 51 is of known type and is suitable for counting the successive logic outputs "1" of the threshold circuit 53 and is connected at its output to a third threshold circuit 60.
  • the third threshold circuit 60 is of the type known and provides a logic signal "1" when the number of cycles leaving the first cycle counter 51 is greater than a value adjustable by coding wheel, for example.
  • the timer circuit 66 is adapted to keep the logic information "1" leaving the third threshold circuit and to transmit it to the alarm output circuit 67 if no reset of the timer circuit has been carried out. by the appearance of a logic signal "1" at the output of the second logic gate 57. It should be noted that the logic signal "1" leaving the third threshold circuit 60 corresponds to the potential alarm information S10 presented in Figures 5.
  • the second cycle counter 52 is of known type and is suitable for counting the number of detection cycles of the threshold crossing output of the threshold circuit 53, if the control signal at the output of the integrator 46 has reached the level logic "1" on logic gate 54.
  • the second cycle counter 52 is connected at its output to a matrixing circuit 63.
  • the matrixing circuit 63 is of known type and is suitable for weighting the values leaving the second cycle counter 52.
  • the statistical integration circuit 56 is adapted to temporally deliver an analog voltage proportional to the number of cycles counted by the counter 52, it is itself connected to the second logic gate 57.
  • the logic gate 57 is finally connected to an input of reset timing circuit 66.
  • FIG. 5 represents signals transmitted by elements of the diagram presented in FIG. 4.
  • FIG. 5 are represented two analog signals SI and S2 leaving the sensor 4, a rectified signal S3, a dynamic signal S4, representative of the rectified average value, a digital logic signal S5, a threshold signal S6, a counting signal S7 and a wake-up signal S8, an analog signal S9 coming from the sensor 6, an alarm information signal S10.
  • the analog signals SI and S2 represent the signals which can leave the interior infrasonic sensor 4 after an intrusion.
  • This signal is a damped sinusoid which can start with a positive part, as for the signal SI or with a negative part, as for the signal S2.
  • the rectified signal S3 is indifferently derived from the rectification of the signal SI or that of the signal S2. This signal is the one leaving the detection chain 29.
  • the dynamic signal S4 is the average value of the rectified signal S3.
  • the digital signal S5 is the signal S3 after digitization on four binary values. The peak value of this signal is indicated below each cycle.
  • the threshold signal S6 is the signal above which the first threshold circuit 45 transmits a logic value "1". It is here equal to a binary value of 1.
  • the counting signal S7 is the digital value leaving the first counting circuit 51.
  • the wake-up signal S8 is the signal leaving the standby and wake-up circuits 48, a signal which controls the power supply of the decision means 59.
  • the analog signal S9 leaving the sensor 6 is here a signal identical to the signal SI but shifted in time by a delay equal to the distance between the infrasonic sensors 4 and 6 divided by the speed of propagation of a pressure wave.
  • the potential alarm information signal S10 is the signal leaving the third threshold circuit 60. It can be seen that this signal goes from logic value “0" to logic value "1” from value 3 of the signal of S7 counting then goes to logic value "0" as soon as signal S9 appears with sufficient voltage. According to the succession of events presented in FIG. 5, the alarm is not triggered because an infrasound has been detected by the external infrasonic sensor 6 just after the appearance of the potential alarm signal. According to the embodiment of the electronic circuit 5 presented in FIGS.
  • the alarm would also not be triggered in the event of detection of infrasound by the external infrasonic sensor 6 for a period extending only a few fractions of a second before the transition to a logic level "1" from the output of the third threshold circuit 60 up to a few fractions of a second after this transition to the logic value "1".
  • the device according to the present invention can also be applied to the monitoring of patients or old people who may be provided with infrasonic transmitters.
  • the invention also relates to a method of detecting intrusion into a building or vehicle.
  • This method consists of capturing infrasound outside the building, capturing infrasound inside the building, comparing the energies of these signals, measuring the phase shift of these signals, the intrusion detection being performed when the ratio of the energies of the infrasounds captured inside the building to those captured outside the building is greater than a first threshold and the phase shift between these infrasounds is greater than a second duration threshold.
  • the method of intrusion detection in a building or in a vehicle also consists in capturing pressure waves outside the building, capturing pressure waves inside the building, comparing the energies of these signals, the measurement of the phase shift of these signals, the intrusion detection being carried out when the ratio of the energies of the pressure waves picked up inside the building to those picked up outside the building is greater than a first threshold and the phase shift between these pressure waves is greater than a second duration threshold.
  • the method of intrusion detection in a building or in a vehicle also consists in capturing infrasound and pressure waves outside the building, capturing infrasound and pressure waves inside of the building, comparison of the energies of these signals, measurement of the phase shift of these signals, intrusion detection being carried out when the ratio of the energies of infrasound and pressure waves captured inside the building to those captured at 1 the building exterior is greater than a first threshold and the phase difference between these infrasound and pressure waves is greater than a second duration threshold.
  • the present invention may receive all arrangements and variants in the field of technical equivalents without departing from this patent.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)

Abstract

Device for detecting an intruder in a building (1) comprising an infrasonic sensor (6) located outside the building, and an infrasonic sensor (4) located inside the building. The device further includes means for dividing the absolute value of the amplitude of a signal supplied by the inside sensor (4) by the absolute value of the amplitude of a signal from the outside sensor (6) after being analyzed and then temporally processed by signal integration. A threshold circuit receiving the signal from the division means detects threshold crossing of the signal from the division means. Means for storing threshold crossing briefly holds the threshold signal. Means for measuring the temporal shift between the signals from both sensors provides a measurement of said shift to an alarm decision means connected to the storage means. The alarm decision means provides, according to the temporal shift measurement, an alarm signal if the storage means provides a threshold crossing signal.

Description

DISPOSITIF DE DETECTION D'INTRUSION DANS UN BATIMENT OU UN VEHICULE PAR DETECTION D'INFRASONS ET /OU D'ONDES DE PRESSION ET PROCEDE DE DETECTION D'INTRUSION.DEVICE FOR DETECTING INTRUSION IN A BUILDING OR VEHICLE BY DETECTING INFRASONS AND / OR PRESSURE WAVES AND METHOD FOR DETECTING INTRUSION.
La présente invention concerne un détecteur d'intrusions dans un bâtiment ou un véhicule par détection d'infrasons, et/ou d'ondes de pression ainsi qu'un procédé de détection d'intrusion dans un bâtiment ou un véhicule. Les détecteurs d'intrusions actuellement connus sont de deux types, les capteurs volumetriques qui détectent des événements dans le volume surveillé, d'une part et les capteurs périmétriques, qui détectent des ouvertures de bâtiment vers l'extérieur, d'autre part. Les premiers possèdent comme principal défaut qu'ils ne détectent des présences qu'après l'intrusion, lorsqu'il est déjà trop tard. Les seconds sont principalement constitués de capteurs placés sur toutes les ouvertures et reliés par réseau filaire à une centrale d'alarme. Dans les deux types de détecteur présentés plus haut, une multitude de capteurs doit être employée pour protéger efficacement un bâtiment. D'autres types de détecteurs permettent de limiter le nombre de capteurs : ce sont les détecteurs infrasonores qui présentent d'une part l'avantage de surveiller l'intégralité du bâtiment avec un seul capteur et d'autre part qui réagissent aux intrusions dès qu'elles surviennent.The present invention relates to an intrusion detector in a building or a vehicle by detection of infrasound, and / or pressure waves as well as a method of intrusion detection in a building or a vehicle. There are two types of intrusion detectors currently known, volumetric sensors which detect events in the monitored volume, on the one hand, and perimeter sensors, which detect building openings to the outside, on the other. The first have the main flaw that they do not detect presence until after the intrusion, when it is already too late. The second are mainly made up of sensors placed on all the openings and connected by wired network to an alarm center. In the two types of detector presented above, a multitude of sensors must be used to effectively protect a building. Other types of detectors make it possible to limit the number of sensors: these are infrasonic detectors which have on the one hand the advantage of monitoring the entire building with a single sensor and on the other hand which react to intrusions as soon as 'they happen.
Les détecteurs d'intrusions par infrasons actuellement connus sont très sensibles aux infrasons d'origine naturelle, par exemple générés par l'action du vent ou d'explosion, sur les parties souples, fenêtres, toiture, portes du bâtiment, et présentent donc un taux d'erreur important, c'est à dire qu'ils génèrent de nombreuses fausses alarmes.Currently known infrared intrusion detectors are very sensitive to infrasound of natural origin, for example generated by the action of wind or explosion, on flexible parts, windows, roofs, doors of the building, and therefore have a high error rate, i.e. they generate many false alarms.
Le problème consiste en la séparation d'une part des ondes de pressions et infrasons provenant d'événements externes au bâtiment, qui doivent être ignorés, et d'autre part des ondes de pression et infrasons provenant des événements internes au bâtiment, qui doivent être détectés. L'invention entend remédier à cet inconvénient en présentant un dispositif comportant deux capteurs d'infrasons placés respectivement à l'intérieur et à l'extérieur du volume surveillé et un moyen de comparaison des signaux émis par les dits capteurs.The problem consists in the separation on the one hand of pressure waves and infrasound coming from events external to the building, which must be ignored, and on the other hand from pressure waves and infrasound coming from events internal to the building, which must be detected. The invention intends to remedy this drawback by presenting a device comprising two infrared sensors placed respectively inside and outside the monitored volume and a means of comparing the signals emitted by said sensors.
Les deux capteurs sont reliés, par fil ou par radio à un circuit électronique qui est adapté à détecter la correspondance, y compris avec une avance ou un retard de quelques fractions de seconde, entre des signaux infrasonores captés par les deux capteurs, correspondance prouvant l'origine extérieure de ces signaux. Un signal capté par le capteur intérieur et ne correspondant à aucun signal externe est considéré comme une intrusion et déclenche une alarme, une transmission téléphonique, par exemple.The two sensors are connected, by wire or by radio to an electronic circuit which is adapted to detect the correspondence, including with an advance or a delay of a few fractions of a second, between infrasonic signals picked up by the two sensors, correspondence proving the external origin of these signals. A signal picked up by the interior sensor and not corresponding to any external signal is considered as an intrusion and triggers an alarm, a telephone transmission, for example.
Le dispositif objet de la présente invention est ainsi un dispositif de détection d'intrusions dans un bâtiment caractérisé en ce qu'il comporte d'une part un capteur infrasonore placé à l'extérieur du bâtiment, d'autre part un capteur infrasonore placé à l'intérieur du bâtiment, un moyen de division de la valeur absolue de l'amplitude d'un signal provenant du capteur intérieur sur la valeur absolue de l'amplitude d'un signal provenant du capteur extérieur et d'un signal provenant d'un circuit intégrateur intégrant 1'amplitude moyenne du capteur extérieur pendant une durée de quelques fractions de secondes assurant ainsi un asservissement automatique de la sensibilité du franchissement de seuil d'un circuit à seuil recevant le signal sortant du moyen de division, un moyen de mémorisation du franchissement du dit seuil, un moyen de mesure du décalage temporel entre les signaux provenant des deux capteurs et un moyen de transmission de signaux d'alarme relié d'une part au moyen de mémorisation et d'autre part au moyen de mesure de décalage temporel. La description qui va suivre, faite en regard des dessins annexés dans un but explicatif et nullement limitatif, permet de mieux comprendre les avantages, buts et caractéristiques de l'invention. La figure 1 représente l'implantation du dispositif dans un bâtiment.The device which is the subject of the present invention is thus a device for detecting intrusions into a building, characterized in that it comprises, on the one hand, an infrasonic sensor placed outside the building, on the other hand, an infrared sensor placed at inside the building, a means of dividing the absolute value of the amplitude of a signal from the indoor sensor onto the absolute value of the amplitude of a signal from the outdoor sensor and a signal from an integrator circuit integrating the average amplitude of the external sensor for a period of a few fractions of seconds thus ensuring automatic control of the sensitivity of the threshold crossing of a threshold circuit receiving the signal leaving the division means, a storage means crossing the said threshold, a means of measuring the time difference between the signals from the two sensors and a means of transmitting alarm signals connected to a firstly by means of storage and secondly by means of time offset measurement. The description which follows, made with reference to the accompanying drawings for explanatory purposes and in no way limiting, allows a better understanding of the advantages, aims and characteristics of the invention. Figure 1 shows the layout of the device in a building.
La figure 2 représente un capteur infrasonore incorporé dans le dispositif présenté en figure 1. La figure 3 représente un schéma bloc d'un circuit électronique de comparaison de signaux émis par deux capteurs présentés en figure 2.FIG. 2 represents an infrasonic sensor incorporated in the device presented in FIG. 1. FIG. 3 represents a block diagram of an electronic circuit for comparing signals emitted by two sensors presented in FIG. 2.
La figure 4 représente un schéma électronique du circuit présenté en figure 3. La figure 5 représente des signaux transmis par des éléments du circuit présenté en figure 3.FIG. 4 represents an electronic diagram of the circuit presented in FIG. 3. FIG. 5 represents signals transmitted by elements of the circuit presented in FIG. 3.
Dans la figure 1 sont représentés un bâtiment 1 comportant une porte 2 et une fenêtre 3, un capteur infrasonore intérieur 4, un circuit électronique de comparaison 5 et un capteur infrasonore extérieur 6 placé à l'extérieur du bâtiment 1.In FIG. 1 are shown a building 1 comprising a door 2 and a window 3, an interior infrasonic sensor 4, an electronic comparison circuit 5 and an exterior infrasonic sensor 6 placed outside the building 1.
Le bâtiment 1 est de type quelconque mais ne présente pas d'ouverture naturelle permanente, est relativement étanche aux courants d'air, ne possède pas de murs ou de toiture trop souple. La porte 2 et la fenêtre 3 sont fermées lorsque le dispositif est en état de surveillance et qu'aucune intrusion n'a lieu.The building 1 is of any type but does not have a permanent natural opening, is relatively impermeable to drafts, has no walls or too flexible roofing. Door 2 and window 3 are closed when the device is in the surveillance state and no intrusion takes place.
Le capteur infrasonore intérieur 4 est présenté en figure 2. Il est adapté à capter les infrasons ambiants à l'intérieur du bâtiment et à émettre un signal électrique représentatif de l'intensité des ondes infrasonores lui parvenant.The interior infrasound sensor 4 is presented in FIG. 2. It is adapted to pick up ambient infrasound inside the building and to emit an electrical signal representative of the intensity of the infrasonic waves reaching it.
Le capteur infrasonore extérieur 6 est présenté en figure 2. Il est adapté à capter les infrasons ambiants à l'extérieur du bâtiment et à émettre un signal électrique approximativement proportionnel à l'intensité des ondes infrasonores lui parvenant.The exterior infrasound sensor 6 is presented in FIG. 2. It is adapted to pick up ambient infrasound outside the building and to emit an electrical signal approximately proportional to the intensity of the infrasonic waves reaching it.
Le circuit électronique de comparaison 5 est présenté en figure 3. Il est relié d'une part au capteur infrasonore intérieur 4 et d'autre part au capteur infrasonore extérieur 6 et est adapté à comparer les signaux émis par les capteurs infrasonores 4 et 6. Le principe de fonctionnement du dispositif est le suivant : le seuil de détection d'infrasons intérieurs est fonction de la sortie d'un moyen de division de la valeur absolue de l'amplitude d'un signal provenant du capteur intérieur sur la valeur absolue de l'amplitude d'un signal provenant du capteur extérieur et d'un signal provenant d'un circuit intégrateur intégrant l'amplitude moyenne du capteur extérieur pendant une durée de quelques fractions de secondes et du nombre d'oscillations de l'onde infrasonore dépassant un certain seuil. Lorsque cette détection est obtenue, une détection identique à l'extérieur du bâtiment peut en annuler l'effet.The electronic comparison circuit 5 is presented in FIG. 3. It is connected on the one hand to the interior infrasonic sensor 4 and on the other hand to the exterior infrasonic sensor 6 and is adapted to compare the signals emitted by the infrasonic sensors 4 and 6. The operating principle of the device is as follows: the threshold for detecting indoor infrasound is a function of the output of a means of dividing the absolute value of the amplitude of a signal from the indoor sensor onto the absolute value of the amplitude of a signal from the outdoor sensor and a signal from an integrator circuit integrating the average amplitude of the outdoor sensor for a period of a few fractions of seconds and the number of oscillations of the infrasonic wave exceeding a certain threshold. When this detection is obtained, an identical detection outside the building can cancel the effect.
En effet, les infrasons se déplacent beaucoup plus vite que les ondes de pression. Lorsqu'une onde de pression rencontre un obstacle souple, comme une porte, une fenêtre ou une toiture, par exemple, celui-ci génère des infrasons. Ces infrasons forment une enveloppe de l'onde de pression initiale qui est captée avec un délai d'avance ou de retard de manière identique par le capteur infrasonore extérieur 6 et par le capteur infrasonore intérieur 4.In fact, infrasound moves much faster than pressure waves. When a pressure wave encounters a flexible obstacle, such as a door, window or roof, for example, it generates infrasound. These infrasounds form an envelope of the initial pressure wave which is picked up with a time delay or delay in an identical manner by the exterior infrasonic sensor 6 and by the interior infrasonic sensor 4.
Par contre, lors d'une intrusion dans le bâtiment surveillé, des infrasons sont émis par l'ouverture d'une porte ou d'une fenêtre.On the other hand, during an intrusion into the monitored building, infrasound is emitted by the opening of a door or a window.
Ces infrasons sont captés par le capteur infrasonore intérieur mais pas par le capteur infrasonore extérieur. La comparaison des signaux provenant des deux capteurs infrasonores, comparaison réalisée par le circuit électronique de comparaison 5, permet ainsi de différencier les infrasons provenant d'événements externes au bâtiment surveillé qui ne sont pas liés à des intrusions d'une part et les infrasons provenant d'événements internes au bâtiment surveillé qui indiquent une intrusion, d'autre part.These infrasound are picked up by the indoor infrasonic sensor but not by the outdoor infrasonic sensor. The comparison of the signals coming from the two infrasonic sensors, comparison carried out by the electronic comparison circuit 5, thus makes it possible to differentiate the infrasound coming from events external to the monitored building which are not linked to intrusions on the one hand and the infrasound coming of events inside the monitored building that indicate an intrusion, on the other hand.
Le circuit de comparaison 5 est d'abord adapté à réaliser une division de l'intensité infrasonore àThe comparison circuit 5 is first adapted to perform a division of the infrasonic intensity at
1'intérieur du bâtiment 1 par 1'intensité infrasonore moyenne à 1'extérieur du bâtiment 1, mesurée pendant une durée précédant l'instant de division. Lorsque cette division dépasse un seuil, le circuit 5 est adapté à émettre une information d'alarme potentielle. Lorsque le signal provenant du capteur infrasonore externe 6 est supérieur à un autre seuil pendant les quelques fractions de secondes suivant l'émission de l'information d'alarme potentielle, l'in ormation d'alarme potentielle est désactivée, une réactivation de cette information d'alarme ne pouvant être réalisée pendant une durée de l'ordre d'une seconde suivant la désactivation. L'information d'alarme potentielle devient un signal d'alarme uniquement si l'information d'alarme potentielle n'est pas désactivée. De cette manière, il n'y a alarme qu'en fonction de l'ambiance infrasonore, souvent liée à la météorologie, et que si une réception infrasonore intense à 1'intérieur du bâtiment 1 n'est pas précédée ni suivie d'une réception infrasonore intense à l'extérieur du bâtiment, dans une durée s'étendant de quelques secondes avant la réception interne à quelques secondes après cette réception. Ce fonctionnement est décrit en figures 3, 4 et 5 ci-dessous.Inside building 1 by the average infrasonic intensity outside building 1, measured for a period preceding the instant of division. When this division exceeds a threshold, circuit 5 is adapted to transmit potential alarm information. When the signal coming from the external infrasonic sensor 6 is higher than another threshold during the few fractions of seconds following the emission of the potential alarm information, the potential alarm information is deactivated, a reactivation of this information alarm cannot be carried out for a period of the order of one second following deactivation. The potential alarm information becomes an alarm signal only if the potential alarm information is not deactivated. In this way, there is an alarm only according to the infrasonic environment, often linked to meteorology, and only if an intense infrasonic reception inside building 1 is not preceded or followed by a intense infrasonic reception outside the building, lasting from a few seconds before the internal reception to a few seconds after this reception. This operation is described in Figures 3, 4 and 5 below.
Il est important de noter que les nombres de capteurs internes ou externes ne sont pas limités à un mais qu'il est indispensable qu'il y ait au moins un capteur interne et un capteur externe. La figure 2 représente un capteur infrasonore incorporé dans le dispositif présenté en figure 1. Dans la figure 2 sont représentés un capteur infrasonore 4 et un capteur infrasonore 6. Les capteurs infrasonores 5 et 6 comportent chacun un environnement 10, un capillaire 11, une chambre de résonance 12 et un capteur acousto-électrique 13. Le capteur 13 est placé dans la chambre de résonance 12 laquelle est ménagée dans le capteur et est en communication avec 1'extérieur par l'intermédiaire du capillaire 11 , lequel se présente sous la forme d'un élément tubulaire de faible diamètre. L'environnement 10 est l'air ambiant, soit à l'intérieur du bâtiment 1, pour le capteur infrasonore intérieur 4 soit à l'extérieur du bâtiment 1, pour le capteur infrasonore externe 6. Le capillaire 11 réalise une ouverture très étroite entre 1'air présent à 1'intérieur de la chambre de résonance 12 et l'environnement 10, et il possède un diamètre interne adapté à ne laisser passer que les basses fréquences inférieures à vingt Hertz. La chambre de résonance 12 combinée au capillaire 11 est adaptée à résonner aux fréquences infrasonores recherchées. Enfin le capteur acousto-électriquel3 est adapté à transformer en signal électrique le signal infrasonore qui lui parvient à 1'intérieur de la chambre de résonance 12. Le capteur acousto-électrique 13 peut être constitué d'un microphone à effet électret, par exemple. Il est à noter que la forme de la chambre de résonance 12 et, par conséquent, celle du capteur infrasonore 4, peut être parallèlipipédique, cylindrique ou sphérique.It is important to note that the numbers of internal or external sensors are not limited to one but that it is essential that there is at least one internal sensor and one external sensor. FIG. 2 represents an infrasonic sensor incorporated in the device presented in FIG. 1. In FIG. 2 are shown an infrasonic sensor 4 and an infrasonic sensor 6. The infrasonic sensors 5 and 6 each include an environment 10, a capillary 11, a chamber resonance 12 and an acoustoelectric sensor 13. The sensor 13 is placed in the resonance chamber 12 which is formed in the sensor and is in communication with the outside via the capillary 11, which is in the form of a tubular element of small diameter. The environment 10 is the ambient air, either inside the building 1, for the indoor infrasonic sensor 4 or outside the building 1, for the external infrasonic sensor 6. The capillary 11 makes a very narrow opening between the air present inside the resonance chamber 12 and the environment 10, and it has an internal diameter adapted to allow only the lower low frequencies to pass through. at twenty Hertz. The resonance chamber 12 combined with the capillary 11 is adapted to resonate at the desired infrasonic frequencies. Finally, the acoustoelectric sensor 3 is adapted to transform the infrasonic signal which reaches it inside the resonance chamber 12 into an electrical signal. The acoustoelectric sensor 13 can consist of an electret effect microphone, for example. It should be noted that the shape of the resonance chamber 12 and, consequently, that of the infrasonic sensor 4, can be parallelipipedic, cylindrical or spherical.
Ce capteur est d'une part très sensible et d'autre part limité à une gamme de fréquence dans les infrasons. La figure 3 représente un schéma bloc d'un circuit électronique de comparaison de signaux émis par deux capteurs présentés en figure 2.This sensor is on the one hand very sensitive and on the other hand limited to a frequency range in infrasound. FIG. 3 represents a block diagram of an electronic circuit for comparing signals emitted by two sensors presented in FIG. 2.
Dans la figure 3 sont représentés quatre capteurs infrasonores 41, 42, 61 et 62, deux filtres passe-bande et deux amplificateurs 15 et 16 reliés respectivement aux capteurs infrasonores 41 et 42 d'une part et aux capteurs infrasonores 61 et 62 d'autre part, un convertisseur analogique-numérique 23 et un convertisseur numérique- analogique 24, un moyen de traitement de signaux 17, un moyen de réglage de sensibilités 18, un moyen de commande d'alarme et d'afficheur 20, un relais de sortie d'alarme 21 et un afficheur 22.In FIG. 3 are represented four infrasonic sensors 41, 42, 61 and 62, two bandpass filters and two amplifiers 15 and 16 connected respectively to the infrasonic sensors 41 and 42 on the one hand and to the infrasonic sensors 61 and 62 on the other hand, an analog-digital converter 23 and a digital-analog converter 24, a signal processing means 17, a sensitivity adjustment means 18, an alarm and display control means 20, an output relay d alarm 21 and a display 22.
Les capteurs infrasonores 41, 42, 61 et 62 sont de même type que celui présenté en figure 2. Les capteurs 41, 42 et 61 sont placés à l'intérieur du bâtiment 1, les capteurs infrasonores 41 et 42 étant placés dans le local surveillé et le capteur infrasonore 61 étant placé à l'extérieur du local surveillé. Le capteur 62 est placé à l'extérieur du bâtiment 1. Les capteurs 41 et 42 servent à mesurer les infrasons à 1'intérieur du bâtiment 1 et les capteurs 61 et 62 servent à contrôler l'origine des infrasons présents à 1'intérieur du bâtiment 1. Les capteurs infrasonores 42 et 61 ne sont pas indispensables au fonctionnement du dispositif mais ils permettent d'augmenter le contrôle de l'origine intérieure ou extérieure des infrasons détectés.The infrasonic sensors 41, 42, 61 and 62 are of the same type as that presented in FIG. 2. The sensors 41, 42 and 61 are placed inside the building 1, the infrasonic sensors 41 and 42 being placed in the monitored room and the infrasonic sensor 61 being placed outside the monitored room. The sensor 62 is placed outside the building 1. The sensors 41 and 42 are used to measure the infrasound inside the building 1 and the sensors 61 and 62 are used to control the origin of infrasound present inside the building 1. The infrasonic sensors 42 and 61 are not essential for the operation of the device but they make it possible to increase the control of the interior or exterior origin infrasound detected.
Les deux amplificateurs 15 et 16 sont de type connu et sont adaptés à amplifier le signal sortant des capteurs infrasonores de telle manière qu'ils fournissent le même signal pour le même infrason initial. Les convertisseurs analogique-numérique 23 et numérique-analogique 24 sont de type connu et adaptés à émettre respectivement un signal numérique et un signal analogique représentatifs respectivement du signal analogique et du signal numérique qu'ils reçoivent des amplificateurs 15 et 16.The two amplifiers 15 and 16 are of known type and are adapted to amplify the signal leaving the infrasonic sensors so that they provide the same signal for the same initial infrasonic. The analog-to-digital converters 23 and digital-to-analog 24 are of known type and adapted to transmit respectively a digital signal and an analog signal representative respectively of the analog signal and of the digital signal which they receive from the amplifiers 15 and 16.
Le moyen de traitement de signaux 17 est adapté pour réaliser une fonction de transfert entre les données qu'il reçoit et les données qu'il émet et, en particulier, à effectuer un ratio de l'amplitude du signal provenant des capteurs infrasonores internes 41 et 42 sur l'amplitude du signal provenant des capteurs infrasonores 61 et 62. Il comporte un premier circuit possédant un premier seuil et fournissant une information d'alarme potentielle dès que le ratio est supérieur au seuil fixé. Cette information d'alarme est annulée par un second circuit possédant un second seuil relié au capteur infrasonore externe 62, si ledit second seuil est dépassé pendant une durée donnée précédant ou suivant l'apparition de l'information d'alarme potentielle. Le moyen de réglage de sensibilités 18 est de type connu et est adapté à commander la valeur des seuils présentés ci-dessus.The signal processing means 17 is adapted to perform a transfer function between the data it receives and the data it transmits and, in particular, to perform a ratio of the amplitude of the signal coming from the internal infrasonic sensors 41 and 42 on the amplitude of the signal from the infrasonic sensors 61 and 62. It comprises a first circuit having a first threshold and providing potential alarm information as soon as the ratio is above the fixed threshold. This alarm information is canceled by a second circuit having a second threshold connected to the external infrasonic sensor 62, if said second threshold is exceeded for a given duration preceding or following the appearance of the potential alarm information. The sensitivity adjustment means 18 is of known type and is suitable for controlling the value of the thresholds presented above.
Le moyen de commande d'alarme et d'afficheur 20 est adapté à annuler l'information d'alarme potentielle et à émettre vers l'afficheur 20 soit un signal d'information d'alarme potentielle annulée, soit un signal d'information d'alarme potentielle confirmée, selon que l'annulation a été réalisée ou non. Il est aussi adapté à commander la position passante du relais de sortie d'alarme 21 lorsque l'information d'alarme potentielle n'est pas annulée.The alarm control and display means 20 are adapted to cancel the potential alarm information and to send to the display 20 either a canceled potential alarm information signal or an information signal d 'potential alarm confirmed, depending on whether the cancellation has been made or not. It is also suitable for controlling the passing position of the alarm output relay 21 when the potential alarm information is not canceled.
Le relais de sortie d'alarme 21 est de type connu et permet de relier n'importe quel type de système électrique au dispositif. En particulier, ce relais de sortie d'alarme 21 peut être relié à une centrale d'alarme, à un transmetteur téléphonique, à une sirène, à un allumage de lampes, par exemple.The alarm output relay 21 is of known type and allows any type of electrical system to be connected to the device. In particular, this alarm output relay 21 can be connected to an alarm center, to a telephone transmitter, to a siren, to a lighting of lamps, for example.
L'afficheur 22 est uniquement destiné à la vérification du bon fonctionnement du dispositif. Il est de type connu, par exemple constitué d'une rangée de diodes électroluminescentes.The display 22 is only intended for checking the correct operation of the device. It is of known type, for example consisting of a row of light-emitting diodes.
Le convertisseur analogique-numérique 23 est incorporé au moyen de traitement de signaux 17 et convertit les signaux analogiques provenant des amplificateurs 15 et 16 et du convertisseur numérique-analogique 24 en signaux numériques.The analog-to-digital converter 23 is incorporated into the signal processing means 17 and converts the analog signals from the amplifiers 15 and 16 and from the digital-to-analog converter 24 into digital signals.
Le convertisseur numérique-analogique 24 est adapté à transformer temporellement en signaux analogiques les signaux numériques qu'il reçoit du moyen de traitement de signaux 17.The digital-analog converter 24 is adapted to transform temporally into analog signals the digital signals which it receives from the signal processing means 17.
Selon cette organisation, le moyen de traitement des signaux 17 sortant des capteurs infrasonores 41, 42, 61 et 62 est combinatoire et séquentiel. En effet, il combine les signaux sortant des capteurs infrasonores à des signaux sortant de lui-même et comporte des intégrateurs temporels.According to this organization, the means for processing the signals 17 leaving the infrasonic sensors 41, 42, 61 and 62 is combinatorial and sequential. Indeed, it combines the signals leaving the infrasonic sensors with signals leaving itself and includes time integrators.
La figure 4 représente un schéma électronique du circuit présenté en figure 3. Dans la figure 4 sont représentés une chaîne de détection 29 comportant le capteur infrasonore interne 4, un pont de résistances 30, un amplificateur ajustable 31, un filtre passe-bande 32, un amplificateur de chaîne 33 et un redresseur double alternance 34. Dans la figure 4 sont aussi représentés une chaîne de contrôle 39 comportant le capteur infrasonore externe 6, un pont de résistances 40, un amplificateur ajustable 64, un filtre passe-bande 65, un amplificateur de chaîne 43 et un redresseur 44. Le redresseur double alternance 34 est relié d'une part à un premier circuit à seuil 45, d'autre part à un premier intégrateur 46 et encore d'autre part à un ratiomètre convertisseur analogique-numérique 47. Le circuit à seuil 45 est relié d'une part à un premier compteur de cycles 51, d'autre part à un circuit de veille et de réveil 48 et encore d'autre part à un second compteur de cycles 52. Le redresseur double alternance 44 est relié d'une part à un second intégrateur 49 et d'autre part au premier intégrateur 46. Le premier intégrateur 46 et le second intégrateur 49 sont reliés aux entrées d'un sommateur 50 dont la sortie est reliée au convertisseur analogique numérique 47. Le convertisseur analogique numérique 47 est relié à un second circuit à seuil 53 lui même relié au premier compteur de cycles 51, d'une part, et à une première porte logique 54, d'autre part. Le premier intégrateur 46 est relié en ses entrées à une alimentation de référence 55, au redresseur double alternance 34, au redresseur double alternance 44 et à un intégrateur statistique 56, et en ses sorties au sommateur 50, à la première porte logique 54 et à une seconde porte logique 57. Le circuit de veille et de réveil 48 est relié à une alimentation 58 du moyen de décision 59. Le premier compteur de cycles 51 est relié en sa sortie à un troisième circuit à seuil 60, lui-même relié à un circuit de temporisation 66, lui-même relié à un circuit de sortie d'alarme 67. Le second compteur de cycles 52 est relié à un circuit de matriçage 63, lui-même relié au circuit d'intégration statistique 56, lui-même relié à la seconde porte logique 57. La porte logique 57 est enfin reliée à une entrée de remise à zéro du circuit de temporisation 61. Le moyen de décision 59 comporte les compteurs de cycles 51 et 52, les portes logiques 54 et 57, le circuit à seuil 60, le circuit de temporisation 66, le circuit de sortie d'alarme 67, le circuit de matriçage 63 et le circuit d'intégration statistique 56.FIG. 4 represents an electronic diagram of the circuit presented in FIG. 3. In FIG. 4 are shown a detection chain 29 comprising the internal infrasonic sensor 4, a resistance bridge 30, an adjustable amplifier 31, a bandpass filter 32, a chain amplifier 33 and a full-wave rectifier 34. In FIG. 4 are also shown a control chain 39 comprising the external infrasonic sensor 6, a resistance bridge 40, an adjustable amplifier 64, a bandpass filter 65, a chain amplifier 43 and a rectifier 44. The full-wave rectifier 34 is connected on the one hand to a first circuit at threshold 45, on the other hand to a first integrator 46 and again on the other hand to an analog-digital converter ratiometer 47. The threshold circuit 45 is connected on the one hand to a first cycle counter 51, on the other hand to a standby and wake-up circuit 48 and again on the other hand to a second cycle counter 52. The full-wave rectifier 44 is connected on the one hand to a second integrator 49 and on the other hand to the first integrator 46. The first integrator 46 and second integrator 49 are connected to the inputs of an adder 50 whose output is connected to analog digital converter 47. Analog digital converter 47 is connected to a second threshold circuit 53 itself connected to the first cycle counter 51, on the one hand, and to a first logic gate 54, on the other hand. The first integrator 46 is connected at its inputs to a reference supply 55, to the full-wave rectifier 34, to the full-wave rectifier 44 and to a statistical integrator 56, and at its outputs to the summator 50, to the first logic gate 54 and to a second logic gate 57. The standby and wake-up circuit 48 is connected to a power supply 58 of the decision means 59. The first cycle counter 51 is connected at its output to a third threshold circuit 60, itself connected to a timer circuit 66, itself connected to an alarm output circuit 67. The second cycle counter 52 is connected to a matrixing circuit 63, itself connected to the statistical integration circuit 56, itself connected to the second logic gate 57. The logic gate 57 is finally connected to a reset input of the timing circuit 61. The decision means 59 comprises the cycle counters 51 and 52, the logic gates 54 and 57, the circuit at threshold 60, the timing circuit 66, the alarm output circuit 67, the matrixing circuit 63 and the statistical integration circuit 56.
La chaîne de détection 29 est destinée à la mise en forme du signal sortant du capteur infrasonore interne 4. Le pont de résistances 30 est ajustable et réglé soit au moment de l'installation soit par l'utilisateur en fonction de la position effective du capteur infrasonore interne 4 afin qu'il possède une sensibilité appropriée.The detection chain 29 is intended for shaping the signal leaving the internal infrasonic sensor 4. The resistance bridge 30 is adjustable and adjusted either at installation time either by the user as a function of the effective position of the internal infrasonic sensor 4 so that it has an appropriate sensitivity.
Par exemple, si le capteur infrasonore 4 est placé dans une armoire presque ëtanche, le pont de résistance sera placé de manière à ne pas limiter l'amplitude du signal sortant du capteur infrasonore interne 4.For example, if the infrasound sensor 4 is placed in an almost watertight cabinet, the resistance bridge will be placed so as not to limit the amplitude of the signal leaving the internal infrasound sensor 4.
L'amplificateur ajustable 31 est, par contre, réglé en usine et ne peut être reréglé qu'après changement du capteur infrasonore interne 4 ou vieillissement de plusieurs années. L'amplificateur ajustable 31 est réglé de telle manière qu'avec une position donnée du pont de résistances 30, la réponse de l'ensemble formé du capteur infrasonore interne 4, du pont de résistances 30 et de l'amplificateur ajustable 31 soit normée.The adjustable amplifier 31 is, on the other hand, adjusted at the factory and can only be re-adjusted after changing the internal infrasonic sensor 4 or aging for several years. The adjustable amplifier 31 is adjusted so that with a given position of the resistance bridge 30, the response of the assembly formed by the internal infrasonic sensor 4, the resistance bridge 30 and the adjustable amplifier 31 is normalized.
Le filtre passe-bande 32 est de type connu et est adapté à diminuer l'intensité des signaux électriques lui provenant de l'amplificateur ajustable 31 et possédant des hautes fréquences ou des basses fréquences, par rapport à la fréquence centrale de résonance de la chambre acoustique 12 incorporée dans le capteur infrasonore interne 4.The bandpass filter 32 is of known type and is adapted to reduce the intensity of the electric signals coming from it from the adjustable amplifier 31 and having high frequencies or low frequencies, compared to the central resonance frequency of the chamber. acoustic 12 incorporated in the internal infrasonic sensor 4.
L'amplificateur de chaîne 33 est de type connu et adapté à corriger les dispersions des composants de la chaîne de détection 29. Le redresseur double alternance 34 est de type connu et est adapté à redresser le signal sortant de l'amplificateur de chaîne 33.The chain amplifier 33 is of known type and suitable for correcting the dispersions of the components of the detection chain 29. The full-wave rectifier 34 is of known type and is suitable for rectifying the signal leaving the chain amplifier 33.
La chaîne de contrôle 39 est destinée à la mise en forme du signal sortant du capteur infrasonore externe 6. Le pont de résistances 40 est ajustable et réglé soit au moment de l'installation soit par l'utilisateur en fonction de la position effective du capteur infrasonore externe 6 afin qu'il possède une sensibilité appropriée.The control chain 39 is intended for shaping the signal leaving the external infrasonic sensor 6. The resistance bridge 40 is adjustable and adjusted either at the time of installation or by the user as a function of the effective position of the sensor external infrasonic 6 so that it has an appropriate sensitivity.
L'amplificateur ajustable 64 est, par contre, réglé en usine et ne peut être reréglé qu'après changement du capteur infrasonore externe 6 ou vieillissement de plusieurs années. L'amplificateur ajustable 64 est réglé de telle manière qu'avec une position donnée du pont de résistances 40, la réponse de l'ensemble formé du capteur infrasonore externe 6, du pont de résistances 40 et de l'amplificateur ajustable 64 soit normée.The adjustable amplifier 64, on the other hand, is factory set and can only be re-adjusted after changing the external infrasonic sensor 6 or aging for several years. The adjustable amplifier 64 is adjusted in such a way that with a given position of the resistance bridge 40, the response of the assembly formed by the external infrasonic sensor 6, the resistance bridge 40 and the adjustable amplifier 64 is normalized.
Le filtre passe-bande 65 est identique au filtre passe-bande 32.The bandpass filter 65 is identical to the bandpass filter 32.
L'amplificateur de chaîne 43 est de type connu et adapté à corriger les dispersions des composants de la chaîne de contrôle 39.The chain amplifier 43 is of known type and suitable for correcting the dispersions of the components of the control chain 39.
Le redresseur double alternance 44 est de type connu et est adapté à redresser le signal sortant de l'amplificateur de chaîne 43.The full-wave rectifier 44 is of known type and is suitable for rectifying the signal leaving the chain amplifier 43.
Le redresseur 34 est relié d'une part à un premier circuit à seuil 45, d'autre part à un premier intégrateur 46 et encore d'autre part à un convertisseur analogique- numérique 47. Le premier circuit à seuil 45 est de type connu et fournit un signal logique "1" lorsque le signal sortant du redresseur double alternance 34 dépasse instantanément une valeur de seuil fixée. Le premier intégrateur 46 possède une constante de temps très élevée et fournit donc un signal variant lentement par rapport à la fréquence des ondes infrasonores détectées.The rectifier 34 is connected on the one hand to a first threshold circuit 45, on the other hand to a first integrator 46 and also on the other hand to an analog-digital converter 47. The first threshold circuit 45 is of known type and supplies a logic signal "1" when the signal leaving the full-wave rectifier 34 instantly exceeds a fixed threshold value. The first integrator 46 has a very high time constant and therefore provides a signal varying slowly with respect to the frequency of the detected infrasonic waves.
Le ratiomètre convertisseur analogique numérique 47 est de type connu. Sa tension de référence est fournie par le sommateur 50 et il est adapté à fournir un signal numérique proportionnel à la différence du signal lui parvenant de la chaîne de détection 29 et de la tension de référence fournie par le sommateur 50. Le circuit à seuil 45 est relié en sa sortie d'une part à un premier compteur de cycles 51, d'autre part à un circuit de veille et de réveil 48 et encore d'autre part à un second compteur de cycles 52.The analog digital converter ratiometer 47 is of known type. Its reference voltage is supplied by the adder 50 and it is adapted to supply a digital signal proportional to the difference of the signal reaching it from the detection chain 29 and the reference voltage supplied by the adder 50. The threshold circuit 45 is connected at its output on the one hand to a first cycle counter 51, on the other hand to a standby and wake-up circuit 48 and again on the other hand to a second cycle counter 52.
Le circuit à seuil 45 provoque sur les compteurs de cycles 51 et 52 l'autorisation de compter pendant une durée de réveil.The threshold circuit 45 causes on the cycle counters 51 and 52 the authorization to count during a wake-up time.
Le circuit de veille et de réveil 48 est adapté à commander la mise en alimentation du moyen de décision 59 par l'alimentation 58, à maintenir cette alimentation pendant une durée de plusieurs secondes après le dernier signal logique "1" sortant du circuit à seuil 45.The standby and wake-up circuit 48 is adapted to control the supply of power to the decision means 59 by the supply 58, to maintain this supply for a period of several seconds after the last logic signal "1" leaving the threshold circuit 45.
Cette disposition a pour avantage d'économiser l'énergie et de maintenir une alarme effective en état de fonctionnement même après une mise en veille, c'est-à-dire une coupure d'alimentation par le circuit de veille et de réveil 48, ainsi qu'en dehors de l'état d'alarme effective d'empêcher les déclenchements d'alarme par des signaux logiques parasites ou de puissances en sortie alarme venant des circuits de décision 59.This arrangement has the advantage of saving energy and of maintaining an effective alarm in working condition even after being put on standby, that is to say a power cut by the standby and wake-up circuit 48, as well as outside the effective alarm state to prevent alarm triggers by parasitic logic signals or alarm output powers coming from the decision circuits 59.
Le redresseur double alternance 44 est relié d'une part à un second intégrateur 49 et d'autre part au premier intégrateur 46. Le second intégrateur 49 possède une constante de temps très inférieure à la constante de temps du premier intégrateur 46 mais supérieure à la pseudo période du signal sortant de la chaîne de contrôle 39.The full wave rectifier 44 is connected on the one hand to a second integrator 49 and on the other hand to the first integrator 46. The second integrator 49 has a time constant much less than the time constant of the first integrator 46 but greater than the pseudo period of the signal leaving the control chain 39.
Le premier intégrateur 46 et le second intégrateur 49 sont reliés aux entrées d'un sommateur 50 dont la sortie est reliée au convertisseur analogique numérique 47. Le sommateur 50 est de type connu et est adapté à additionner les signaux provenant des intégrateurs 46 et 49.The first integrator 46 and the second integrator 49 are connected to the inputs of an adder 50 whose output is connected to the analog-to-digital converter 47. The adder 50 is of known type and is suitable for adding the signals coming from integrators 46 and 49.
La sortie du convertisseur analogique numérique 47 est reliée à un second circuit à seuil 53. Le second circuit à seuil 53 est de type connu et fournit un signal logique "1" lorsque le signal sortant du convertisseur analogique numérique 47 dépasse un seuil réglable, par roue codeuse, par exemple. La sortie du second circuit à seuil 53 est reliée au premier compteur de cycles 51, d'une part, et à une première porte logique 54, d'autre part.The output of the analog digital converter 47 is connected to a second threshold circuit 53. The second threshold circuit 53 is of known type and provides a logic signal "1" when the signal leaving the analog digital converter 47 exceeds an adjustable threshold, by encoder wheel, for example. The output of the second threshold circuit 53 is connected to the first cycle counter 51, on the one hand, and to a first logic gate 54, on the other hand.
Le premier intégrateur 46 est relié en ses entrées à une alimentation de référence 55, au redresseur double alternance 34, au redresseur double alternance 44 et à l'intégrateur statistique 56, et en ses sorties au sommateur 50, à la première porte logique 54 et à la seconde porte logique 57. L'alimentation de référence 55 est constituée de la demi- tension de l'alimentation du dispositif.The first integrator 46 is connected at its inputs to a reference supply 55, to the full wave rectifier 34, to the full wave rectifier 44 and to the statistical integrator 56, and at its outputs to the summator 50, to the first logic gate 54 and at the second logic gate 57. The reference supply 55 consists of the half voltage of the supply to the device.
Le premier compteur de cycles 51 est de type connu et est adapté à compter les sorties logiques "1" successives du circuit à seuil 53 et est relié en sa sortie à un troisième circuit à seuil 60. Le troisième circuit à seuil 60 est de type connu et fournit un signal logique "1" lorsque le nombre de cycles sortant du premier compteur de cycles 51 est supérieur à une valeur réglable par roue codeuse, par exemple. Le circuit de temporisation 66 est adapté à conserver l'information logique "1" sortant du troisième circuit à seuil et à l'émettre vers le circuit de sortie d'alarme 67 si aucune remise à zéro du circuit de temporisation n'a été effectuée par l'apparition d'un signal logique "1" à la sortie de la seconde porte logique 57. Il est à noter que le signal logique "1" sortant du troisième circuit à seuil 60 correspond à l'information d'alarme potentielle S10 présentée en figures 5.The first cycle counter 51 is of known type and is suitable for counting the successive logic outputs "1" of the threshold circuit 53 and is connected at its output to a third threshold circuit 60. The third threshold circuit 60 is of the type known and provides a logic signal "1" when the number of cycles leaving the first cycle counter 51 is greater than a value adjustable by coding wheel, for example. The timer circuit 66 is adapted to keep the logic information "1" leaving the third threshold circuit and to transmit it to the alarm output circuit 67 if no reset of the timer circuit has been carried out. by the appearance of a logic signal "1" at the output of the second logic gate 57. It should be noted that the logic signal "1" leaving the third threshold circuit 60 corresponds to the potential alarm information S10 presented in Figures 5.
Le second compteur de cycles 52 est de type connu et est adapté à compter le nombre de cycles de détection de la sortie de dépassement de seuil du circuit à seuil 53, si le signal de contrôle en sortie de l'intégrateur 46 a atteint le niveau logique "1" sur la porte logique 54. Le second compteur de cycles 52 est relié en sa sortie à un circuit de matriçage 63. Le circuit de matriçage 63 est de type connu et est adaptée à pondérer les valeurs sortant du second compteur de cycles 52.The second cycle counter 52 is of known type and is suitable for counting the number of detection cycles of the threshold crossing output of the threshold circuit 53, if the control signal at the output of the integrator 46 has reached the level logic "1" on logic gate 54. The second cycle counter 52 is connected at its output to a matrixing circuit 63. The matrixing circuit 63 is of known type and is suitable for weighting the values leaving the second cycle counter 52.
Le circuit d'intégration statistique 56 est adapté à délivrer temporellement une tension analogique proportionnelle au nombre de cycles comptés par le compteur 52, il est lui-même relié à la seconde porte logique 57. La porte logique 57 est enfin reliée à une entrée de remise à zéro du circuit de temporisation 66.The statistical integration circuit 56 is adapted to temporally deliver an analog voltage proportional to the number of cycles counted by the counter 52, it is itself connected to the second logic gate 57. The logic gate 57 is finally connected to an input of reset timing circuit 66.
La figure 5 représente des signaux transmis par des éléments du schéma présenté en figure 4.FIG. 5 represents signals transmitted by elements of the diagram presented in FIG. 4.
Dans la figure 5 sont représentés deux signaux analogiques SI et S2 sortant du capteur 4, un signal redressé S3, un signal dynamique S4, représentatif de la valeur moyenne redressée, un signal logique numérique S5, un signal de seuillage S6, un signal de comptage S7 et un signal de réveil S8, un signal analogique S9 sortant du capteur 6, un signal d'information d'alarme S10. Les signaux analogiques SI et S2 représentent les signaux pouvant sortir du capteur infrasonore intérieur 4 après une intrusion. Ce signal est une sinusoïde amortie qui peut commencer par une partie positive, comme pour le signal SI ou par une partie négative, comme pour le signal S2. Le signal redressé S3 est indifféremment issu du redressement du signal SI ou de celui du signal S2. Ce signal est celui sortant de la chaîne de détection 29.In FIG. 5 are represented two analog signals SI and S2 leaving the sensor 4, a rectified signal S3, a dynamic signal S4, representative of the rectified average value, a digital logic signal S5, a threshold signal S6, a counting signal S7 and a wake-up signal S8, an analog signal S9 coming from the sensor 6, an alarm information signal S10. The analog signals SI and S2 represent the signals which can leave the interior infrasonic sensor 4 after an intrusion. This signal is a damped sinusoid which can start with a positive part, as for the signal SI or with a negative part, as for the signal S2. The rectified signal S3 is indifferently derived from the rectification of the signal SI or that of the signal S2. This signal is the one leaving the detection chain 29.
Le signal dynamique S4 est la valeur moyenne du signal redressé S3. Le signal numérique S5 est le signal S3 après numérisation sur quatre valeurs binaires. La valeur crête de ce signal est indiquée en dessous de chaque cycle.The dynamic signal S4 is the average value of the rectified signal S3. The digital signal S5 is the signal S3 after digitization on four binary values. The peak value of this signal is indicated below each cycle.
Le signal de seuillage S6 est le signal au dessus duquel le premier circuit à seuil 45 émet une valeur logique "1". Il est ici égal à une valeur binaire de 1. Le signal de comptage S7 est la valeur numérique sortant du premier circuit de comptage 51. Le signal de réveil S8 est le signal sortant du circuit de veille et de réveil 48, signal qui commande l'alimentation électrique du moyen de décision 59.The threshold signal S6 is the signal above which the first threshold circuit 45 transmits a logic value "1". It is here equal to a binary value of 1. The counting signal S7 is the digital value leaving the first counting circuit 51. The wake-up signal S8 is the signal leaving the standby and wake-up circuits 48, a signal which controls the power supply of the decision means 59.
Le signal analogique S9 sortant du capteur 6 est ici un signal identique au signal SI mais décalé dans le temps d'un retard égal à la distance entre les capteurs infrasonores 4 et 6 divisé par la vitesse de propagation d'une onde de pression.The analog signal S9 leaving the sensor 6 is here a signal identical to the signal SI but shifted in time by a delay equal to the distance between the infrasonic sensors 4 and 6 divided by the speed of propagation of a pressure wave.
Le signal d'information d'alarme potentielle S10 est le signal sortant du troisième circuit à seuil 60. On voit que ce signal passe de la valeur logique "0" à la valeur logique "1" à partir de la valeur 3 du signal de comptage S7 puis passe à la valeur logique "0" dès que le signal S9 apparaît avec un tension suffisante. Selon la succession d'événements présentée en figure 5, l'alarme n'est pas déclenchée parce qu'un infrason à été détecté par le capteur infrasonore extérieur 6 juste après l'apparition du signal d'alarme potentielle. Selon le mode de réalisation du circuit électronique 5 présenté en figure 3 et 4, l'alarme ne serait pas non plus déclenchée en cas de détection d'infrasons par le capteur infrasonore extérieur 6 pendant une durée s'étendant que quelques fractions de seconde avant le passage à un niveau logique "1" de la sortie du troisième circuit à seuil 60 jusqu'à quelques fractions de seconde après ce passage à la valeur logique "1".The potential alarm information signal S10 is the signal leaving the third threshold circuit 60. It can be seen that this signal goes from logic value "0" to logic value "1" from value 3 of the signal of S7 counting then goes to logic value "0" as soon as signal S9 appears with sufficient voltage. According to the succession of events presented in FIG. 5, the alarm is not triggered because an infrasound has been detected by the external infrasonic sensor 6 just after the appearance of the potential alarm signal. According to the embodiment of the electronic circuit 5 presented in FIGS. 3 and 4, the alarm would also not be triggered in the event of detection of infrasound by the external infrasonic sensor 6 for a period extending only a few fractions of a second before the transition to a logic level "1" from the output of the third threshold circuit 60 up to a few fractions of a second after this transition to the logic value "1".
Il est à noter que le dispositif selon la présente invention peut aussi s'appliquer à la surveillance de malades ou de vieillards qui peuvent être munis d'émetteurs infrasonores.It should be noted that the device according to the present invention can also be applied to the monitoring of patients or old people who may be provided with infrasonic transmitters.
L'invention a également pour objet un procédé de détection d'intrusion dans un bâtiment ou véhicule. Ce procédé consiste en la capture d'infrasons à l'extérieur du bâtiment, la capture d'infrasons à l'intérieur du bâtiment, la comparaison des énergies de ces signaux, la mesure du déphasage de ces signaux, la détection d'intrusion étant réalisée lorsque le ratio des énergies des infrasons captés à 1'intérieur du bâtiment sur ceux captés à l'extérieur du bâtiment est supérieur à un premier seuil et le déphasage entre ces infrasons est supérieur à un second seuil de durée.The invention also relates to a method of detecting intrusion into a building or vehicle. This method consists of capturing infrasound outside the building, capturing infrasound inside the building, comparing the energies of these signals, measuring the phase shift of these signals, the intrusion detection being performed when the ratio of the energies of the infrasounds captured inside the building to those captured outside the building is greater than a first threshold and the phase shift between these infrasounds is greater than a second duration threshold.
Le procédé de détection d'intrusion dans un bâtiment ou dans un véhicule consiste également en la capture d'ondes de pression à l'extérieur du bâtiment, la capture d'ondes de pression à l'intérieur du bâtiment, la comparaison des énergies de ces signaux, la mesure du déphasage de ces signaux, la détection d'intrusion étant réalisée lorsque le ratio des énergies des ondes de pression captées à l'intérieur du bâtiment sur celles captées à 1'extérieur du bâtiment est supérieur à un premier seuil et le déphasage entre ces ondes de pression est supérieur à un second seuil de durée. Le procédé de détection d'intrusion dans un bâtiment ou dans un véhicule consiste également en la capture d'infrasons et d'ondes de pression à l'extérieur du bâtiment, la capture d'infrasons et d'ondes de pression à l'intérieur du bâtiment, la comparaison des énergies de ces signaux, la mesure du déphasage de ces signaux, la détection d'intrusion étant réalisée lorsque le ratio des énergies des infrasons et des ondes de pression captés à 1'intérieur du bâtiment sur ceux captés à 1'extérieur du bâtiment est supérieur à un premier seuil et le déphasage entre ces infrasons et ondes de pression est supérieur à un second seuil de durée.The method of intrusion detection in a building or in a vehicle also consists in capturing pressure waves outside the building, capturing pressure waves inside the building, comparing the energies of these signals, the measurement of the phase shift of these signals, the intrusion detection being carried out when the ratio of the energies of the pressure waves picked up inside the building to those picked up outside the building is greater than a first threshold and the phase shift between these pressure waves is greater than a second duration threshold. The method of intrusion detection in a building or in a vehicle also consists in capturing infrasound and pressure waves outside the building, capturing infrasound and pressure waves inside of the building, comparison of the energies of these signals, measurement of the phase shift of these signals, intrusion detection being carried out when the ratio of the energies of infrasound and pressure waves captured inside the building to those captured at 1 the building exterior is greater than a first threshold and the phase difference between these infrasound and pressure waves is greater than a second duration threshold.
La présente invention pourra recevoir tous aménagements et variantes du domaine des équivalents techniques sans pour autant sortir du présent brevet. The present invention may receive all arrangements and variants in the field of technical equivalents without departing from this patent.

Claims

REVENDICATIONS 1/ Dispositif de détection d'intrusion dans un bâtiment caractérisé en ce qu'il comporte d'une part un capteur infrasonore (6,62) placé à l'extérieur du bâtiment, d'autre part un capteur infrasonore (4,41,42,61) placé à l'intérieur du bâtiment, un moyen de division (17,47) de la valeur absolue de l'amplitude d'un signal provenant du capteur intérieur sur la valeur absolue de l'amplitude d'un signal provenant du capteur extérieur, un circuit à seuil (53) recevant le signal sortant du moyen de division, un moyen de mémorisation (51,66) du franchissement du dit seuil, un moyen de mesure du décalage temporel entre les signaux provenant des deux capteurs et un moyen de transmission de signaux d'alarme relié d'une part au moyen de mémorisation et d'autre part au moyen de mesure de décalage temporel.CLAIMS 1 / Intrusion detection device in a building characterized in that it comprises on the one hand an infrasonic sensor (6,62) placed outside the building, on the other hand an infrasonic sensor (4,41 , 42,61) placed inside the building, a means for dividing (17,47) the absolute value of the amplitude of a signal from the interior sensor onto the absolute value of the amplitude of a signal coming from the external sensor, a threshold circuit (53) receiving the signal leaving the dividing means, a means for memorizing (51,66) the crossing of said threshold, a means for measuring the time difference between the signals coming from the two sensors and an alarm signal transmission means connected on the one hand to the storage means and on the other hand to the time offset measurement means.
2/ Dispositif selon la revendication 1 caractérisé en ce qu'il comporte un moyen de traitement des signaux (17) sortant des capteurs infrasonores (4,6,41, 42, 61,62) combinatoire et séquentiel, combinant d'une part les signaux sortant des capteurs infrasonores à des signaux sortant du moyen de traitement des signaux (17) et comportant des intégrateurs temporels.2 / Device according to claim 1 characterized in that it comprises means for processing the signals (17) coming from the infrasonic sensors (4,6,41, 42, 61,62) combinatorial and sequential, combining on the one hand the signals leaving the infrasonic sensors to signals leaving the signal processing means (17) and comprising time integrators.
3/ Dispositif selon la revendication 1 caractérisé en ce que les capteurs d'ondes infrasonores fonctionnent dans une bande de fréquence prédéterminée et comportent un capteur acousto-électrique (13) les dits capteurs d'ondes infrasonores comportent chacun en outre une cavité acoustique (12) entourant le capteur acousto-électrique et un capillaire (11) reliant le volume interne de la cavité acoustique et le volume externe à la cavité acoustique, la fréquence de résonance de la cavité acoustique étant dans la dite bande de fréquence.3 / Device according to claim 1 characterized in that the infrasonic wave sensors operate in a predetermined frequency band and comprise an acoustoelectric sensor (13) the said infrasonic wave sensors each further include an acoustic cavity (12 ) surrounding the acousto-electric sensor and a capillary (11) connecting the internal volume of the acoustic cavity and the external volume to the acoustic cavity, the resonance frequency of the acoustic cavity being in said frequency band.
4/ Dispositif selon l'une quelconque des revendications 1 ou 2 caractérisé en ce que le moyen de division est constitué d'un ratiomètre convertisseur analogique numérique dont l'entrée analogique est reliée à un signal provenant du capteur infrasonore intérieur et dont la tension de référence est reliée à un signal provenant d'un circuit d'intégration (46).4 / Device according to any one of claims 1 or 2 characterized in that the dividing means consists of an analog digital converter ratiometer whose analog input is connected to a signal from the interior infrasonic sensor and whose reference voltage is connected to a signal from an integration circuit (46).
5/ Dispositif selon l'une quelconque des revendications précédentes caractérisé en ce qu'il comporte pour chaque capteur infrasonore une chaîne de traitement du signal comportant un redresseur double alternance (34,44). 6/ Dispositif selon l'une quelconque des revendications précédentes caractérisé en ce qu'il comporte un second circuit à seuil relié à la sortie du moyen de division et fournissant un signal logique "1" lorsque le signal sortant du moyen de division dépasse instantanément une seconde valeur prédéterminée.5 / Device according to any one of the preceding claims characterized in that it comprises for each infrasonic sensor a signal processing chain comprising a full wave rectifier (34,44). 6 / Device according to any one of the preceding claims, characterized in that it comprises a second threshold circuit connected to the output of the dividing means and providing a logic signal "1" when the signal leaving the dividing means instantly exceeds a second predetermined value.
7/ Dispositif selon la revendication 6 caractérisé en ce qu'il comporte un premier compteur de nombre de cycles (51) relié à la sortie du second circuit à seuil et adapté à fournir un signal représentatif du nombre de passage de la valeur logique "0" à la valeur logique "1" de la sortie du second circuit à seuil.7 / Device according to claim 6 characterized in that it comprises a first counter of number of cycles (51) connected to the output of the second threshold circuit and adapted to provide a signal representative of the number of passage of the logic value "0 "at the logic value" 1 "of the output of the second threshold circuit.
8/ Dispositif selon l'une quelconque des revendications précédentes caractérisé en ce qu'il comporte des filtres multipôles (32,42) reliés aux capteurs infrasonores (4,6,41,42,61,62).8 / Device according to any one of the preceding claims, characterized in that it comprises multi-pole filters (32,42) connected to the infrasonic sensors (4,6,41,42,61,62).
9/ Dispositif selon l'une quelconque des revendications précédentes caractérisé en ce qu'au moins un des capteurs infrasonores (61) est placé à l'extérieur du local surveillé et à l'intérieur du bâtiment.9 / Device according to any one of the preceding claims, characterized in that at least one of the infrasonic sensors (61) is placed outside the premises monitored and inside the building.
10/ Procédé de détection d'intrusion dans un bâtiment caractérisé en ce qu'il consiste en la capture d'infrasons et/ou d'ondes de pression à l'extérieur du bâtiment, la capture d'infrasons et/ou d'ondes de pression à l'intérieur du bâtiment, la comparaison des énergies de ces signaux, la mesure du déphasage de ces signaux, la détection d'intrusion étant réalisée lorsque le ratio des énergies des infrasons et/ou d'ondes de pression captés à l'intérieur du bâtiment sur ceux captés à l'extérieur du bâtiment est supérieur à un premier seuil et le déphasage entre ces infrasons et/ou ondes de pression est supérieur à un second seuil de durée. 10 / A method of intrusion detection in a building characterized in that it consists of capturing infrasound and / or pressure waves outside the building, capturing infrasound and / or waves of pressure inside the building, comparison of the energies of these signals, measurement of the phase shift of these signals, intrusion detection being carried out when the ratio of the energies of infrasound and / or of captured pressure waves to l the interior of the building on those received outside the building is greater than a first threshold and the phase shift between these infrasound and / or pressure waves is greater than a second duration threshold.
EP94926262A 1993-09-01 1994-08-31 Device for detecting an intruder in a building or vehicle by infrasonic and/or pressure wave detection and method for so detecting an intruder Withdrawn EP0705469A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9310491 1993-09-01
FR9310491 1993-09-01
PCT/FR1994/001029 WO1995006925A1 (en) 1993-09-01 1994-08-31 Device for detecting an intruder in a building or vehicle by infrasonic and/or pressure wave detection and method for so detecting an intruder

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FR2758201B1 (en) * 1997-01-03 1999-02-26 Damien Bouillet METHOD FOR DISCRIMINATION OF SIGNALS FOR THE DETECTION OF INSTRUMENTS IN A PREMISES, MEANS FOR IMPLEMENTING THE METHOD AND DEVICES COMPRISING SUCH MEANS
GB2334575A (en) * 1998-02-19 1999-08-25 Azur Env Ltd Environmental monitor and alarm having an updated allowable measurement range
SE0102993D0 (en) 2001-09-07 2001-09-07 Astrazeneca Ab New self emulsifying drug delivery system
CN100414569C (en) * 2005-02-07 2008-08-27 青岛海尔数码智能科技有限公司 Wireless safety pre-alarming device of vehicle
WO2011073241A1 (en) * 2009-12-15 2011-06-23 Eyasi Trading Group Lc Method and system for detecting intrusion
DE202013000075U1 (en) 2013-01-03 2013-02-07 Winfried Haumann Alarm system with electronic fingerprint by FFT sound analysis
EP3573031B1 (en) * 2018-05-24 2022-05-11 Infineon Technologies AG System and method for surveillance
IT202100017738A1 (en) * 2021-07-06 2023-01-06 Free Fenix 2 S R L S PERIMETER ANTI-INTRUSION SECURITY SYSTEM

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FR2569027B1 (en) * 1984-03-28 1986-12-05 Vg Electronique Electro Guglie PERIMETRIC INFRASON DETECTION METHOD, INFRASON TREATMENT
FR2596179A1 (en) * 1986-03-18 1987-09-25 Smcm Intruder detection system, applicable especially to an alarm system
JPH071215B2 (en) * 1990-10-31 1995-01-11 住友金属鉱山株式会社 Air pressure change detector

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See references of WO9506925A1 *

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AU7617294A (en) 1995-03-22

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