WO2007057522A1

WO2007057522A1 - Access control device detecting an abnormal temperature of an individual

Info

Publication number: WO2007057522A1
Application number: PCT/FR2005/002872
Authority: WO
Inventors: Charles Laubie
Original assignee: Sema
Priority date: 2005-11-18
Filing date: 2005-11-18
Publication date: 2007-05-24
Also published as: EP1952182A1

Abstract

Access control device comprising uprights 2 delimiting a passage space 4 through which a line of individuals 3 can pass one by one, characterized in that it comprises a sensor array able contactlessly to measure the temperature of a plurality of measurement points 8 distributed throughout the passage space 4, a computer 9 able to receive temperature information about each of the measurement points 8 and, on the basis of parameters contained in a memory, to calculate information regarding the body temperature of the individual 3, and a means for displaying the said information.

Description

Access control device detecting an abnormal temperature of an individual.

The invention relates to the field of devices for controlling the access of individuals. The invention particularly relates to the field of security gates for individuals such as human beings or warm-blooded animals.

In this area, the patent application WO99 / 21148 (IDS Intelligent Detection System) discloses a gantry equipped with X-ray scanner of ^* metal detector, of a millimeter wave camera or a vapor recovery unit. This type of gantry detects if an individual is charged with an object that could be dangerous. But nothing helps to know if an individual has a fever. However, the risks are not only explosive or chemical. There is a risk of contamination of a population by individuals carrying a contagious disease.

To combat the SARS epidemic, thermal video cameras producing an image of a group of individuals have been used. The heat of the head of each individual is visible on the image. This type of temperature detection is expensive because of the cost of heat sensitive video cameras and the need for an operator to interpret the video image.

In the event of a pandemic, traditional methods of controlling epidemics may not be enough. In parallel with traditional methods such as vaccines, it may be desirable to filter access to certain sensitive sites, such as security forces, power distribution nodes, large food distribution stores. It may be desirable to block the entry of these sensitive sites to feverish individuals. There is no need to detect what kind of disease it is, nor to make any diagnosis, but only to emit information meaning that such individual has an abnormal body temperature and that of quickly installable, cheap and automatically working.

JP 7,220,188 (Shimadzu Corp.) discloses an infrared presence sensor disposed at the top of a door of a metropolitan rail vehicle. This type of sensor only serves to detect a presence in the door ajar and a system sends the information to the driver, it is not possible to distinguish a person with fever from another person.

Feverish people have bodies warmer than normal but are covered so that the thermal radiation emitted can be masked. For example, the skull of a feverish individual may be covered with a fur cap so that in certain directions the temperature of the skull may not emit any significant thermal radiation. It is desirable that the detection device be able to distinguish a feverish individual from a healthy individual with a cigarette or having a hot electronic device.

The invention proposes a gantry of detection of a group of individuals, capable of distinguishing a feverish individual from a healthy individual and this in a simple manner.

According to one embodiment of the invention, the access control device comprises amounts defining a passage space one by one of a line of individuals, a sensor assembly able to measure the temperature of a plurality without contact. measuring points distributed in the passage space, a calculator able to receive temperature information from each of the measurement points and to calculate, according to parameters contained in a memory, information concerning the body temperature of the individual, and means for displaying said information. Advantageously, the sensor assembly comprises at least one focusing system defining a detection direction and for each measurement point, an element sensitive to thermal radiation in said detection direction. Advantageously, the passage space comprises at least one privileged zone in which two neighboring measurement points are detected by at least two thermal cameras in at least two detection directions forming an angle between them. According to one variant, the sensor assembly comprises at least one strip thermal camera provided with a plurality of photodiodes, a focusing system corresponding to the plurality of photodiodes, a plurality of measuring points aligned according to a measurement segment. perpendicular to a general direction of detection. The thermal camera with a bar may be provided with a servomotor capable of rotating the measurement segment around the general direction of detection.

Advantageously, the sensor assembly comprises at least one row of thermal imaging cameras with bars of substantially parallel detection general directions and whose measuring segments together form a mesh of a mesh zone of the passage space.

According to another variant, the device comprises a calibrated temperature source whose temperature is measured by at least one measuring point of the sensor assembly.

Advantageously, the distance between two measuring points (8) is greater than 1 cm. The sensitivity wavelength of the sensor assembly may be between 2 and 22 micrometers. The sensor assembly may be able to measure the temperature of the measuring points (8) with a sensitivity of less than 0.5 ^° C. when the temperature of said points (8) is between 34 ° C. and 42 ° C. The sensitivity of the sensor assembly can be improved by comparing the temperature information received from the measurement point measuring the temperature of the calibrated source with the actual temperature of said calibrated source.

Advantageously, the computer is able to eliminate the temperature information corresponding to a heat source passing through the passage space (14) and whose volume is less than a threshold volume or whose temperature is higher than a ceiling temperature.

Advantageously, the device has a standby configuration and a fine detection configuration, a triggering device being able to move the device from one configuration to the other and comprising a non-thermal presence sensor.

According to another embodiment of the invention, the access control method comprises a step where one controls one by one of the individuals, the temperature of a plurality of measurement points is measured without contact, and information about the body temperature of the individual according to parameters, and this information is visualized.

Alternatively, the parameters include a ceiling temperature, and the body temperature information is the highest measured temperature among those below the ceiling temperature.

Advantageously, the visualization of the information comprises the actuation of an indicator when the information concerning the body temperature is greater than a threshold of abnormality.

Advantageously, it raises the temperature of the room where the individuals to be controlled are located at a temperature of at least 23 ⁰ C to encourage said individuals to undress.

Advantageously, the succession of two individuals is detected. Other features and advantages of the invention will appear on reading the detailed description of some embodiments taken as non-limiting examples illustrated by the appended drawings in which:

FIG. 1 is a diagrammatic section along plane I-I of FIG. 3 of an access control device according to the invention,

FIG. 2 is an illustration in section along the plane II-II of FIG. 1 of a thermal camera with a strip, FIG. 3 is a front view of the access control device according to the invention, and

FIG. 4 is an illustration of a mesh zone seen from the plane IV-IV of FIG. 1. As illustrated in FIG. 1, the access control device is located in a detection gantry 1 and comprises two uprights 2 are located to the left and to the right of the trajectory of an individual 3. The uprights 2 define a passage space 4 of the individual 3 preventing two individuals from passing simultaneously under the detection gantry 1 so that the passage space corresponds to a single individual. The access control device comprises a sensor assembly composed of two rows 5 and 5a of thermal cameras 6. Each thermal camera 6 is sensitive to infrared radiation, for example of wavelength between 2 and 22 μm, which propagates in a preferred detection direction 7 and optimizes the reception for radiation from a particular point called "measuring point 8". A computer 9 is connected to the thermal cameras 6 and receives information corresponding to the thermal radiation perceived by the thermal camera 6. An indicator 10 comprises for example three lamps 11 of green, orange and red colors. The computer 9 receives all the temperature information from the thermal cameras 6, takes into account parameters contained in a memory not shown in the computer 9 and calculates information representative of the body temperature of the individual 3. The thermal cameras 6 corresponding to each row of cameras 5 and 5a have detection directions 7 forming an angle between them so that the same thermal zone of an individual will see the thermal radiation it emits more captured by several thermal cameras 6 according to several detection directions 7. The areas of the passage area benefiting from these multiple detections are privileged zones 12. As illustrated in FIG. 2, the thermal camera 6 comprises, for example, a strip of 8 aligned photodiodes 13, a focusing system 14 made for example by a row of 8 silicon microlenses. The photodiode array 13 and the focusing system 14 are perpendicular to a general direction of detection 15. Each photodiode 13 corresponds to a measurement point 8 in a detection direction 7. The detection directions 7 corresponding to each of the photodiodes 13 are distributed on either side of the general direction of detection at an angle of +/- 20 ° for example. Each photodiode 13 corresponds to a measurement point 8 for which the focusing system 14 is optimized. The different measuring points 8 of each of the photodiodes 13 of the thermal camera 6 form a measurement segment 16. This is called a thermal camera with a strip since the number of photodiodes 13 aligned is greater than or equal to 2. The thermal camera at bar is provided with a servomotor 17 for rotating 180 ° about the general direction of detection 15 all photodiodes and possibly the focusing system 14 when it is not axial symmetry. When the servomotor 17 is actuated, the signal perceived by each pixel 13 is representative of the temperature of each of the measuring points 8, these traversing circular arcs around the general direction of detection 15.

As illustrated in FIG. 3, the rows of cameras 5 and 5a are distributed on the two lateral uprights 2 pressed against the detection gantry 1. For a part of the thermal cameras with strip 6, the general detection directions 15 are parallel, the distances measuring points 8 to the uprights 2 may vary from one thermal imaging camera to another, in addition there is overlap of the detection zones of two adjacent thermal imaging cameras 6. Other thermal imagers 6 have general detecting directions 15 plunging or elevating so as to be sure to detect a heat zone irrespective of the environment and the insulating garments coated by the individual. The privileged zone 12 in which the detection of temperature is the thinnest stretches, for example for application with an adult human being from a distance of 1, 45 m from the ground up to 2 m from the ground and covers a central area of the passage space 4 so that an individual 3 can not pass on the sides without obligatorily crossing the privileged zone 12.

The control device may also comprise in the lower part of the detection gantry 1 or the uprights 2 of the presence sensors, not shown in the figure.

The measurement points of each of the thermal array cameras 6 have been shown in the plane of FIG. 3, however, as shown in FIG. 4, the measurement segments 16 may have been pivoted about the general detection directions 15. When the The actuators 17 of certain thermal imagers 6 are actuated, the corresponding detection zone is no longer just a segment 15 but a disk 18 perpendicular to the general direction of detection 15. There is overlapping of the detection zones so as to form a mesh. The area thus meshed has a surface and a thickness, which makes it possible to control an individual without compelling the latter to mark a stop. It may be advantageous to superimpose the preferred detection zone benefiting from several detection directions with the mesh detection zone having a detection thickness.

According to one variant, the access control device comprises a calibrated temperature source which is introduced into the privileged zone 12 for calibrating the temperature information emitted by the thermal imaging cameras 6. It may be advantageous to move the calibrated source of periodically on each of the measuring points 8 of the sensor assembly. For an access control application of adult human individuals, the measurement sensitivity of the thermal imaging cameras is advantageously better than 0.5 degree and preferably of the order of 1/10 degree, especially in the temperature range between 34 ⁰ C and 42 ° C. This temperature range corresponds to the usual human body temperature minus the loss caloric between the outside and the inside of the body and the loss of clothing.

The mesh of the meshed area in measurement points is dense without covering the entire volume, for example a distance between two measurement points at a given instant, greater than 1 cm is sufficient.

The manner in which the computer 9 transforms the plurality of temperature information from the thermal imaging cameras 6 into information concerning the body temperature of the individual 3 will now be described. The sensitivity frequency band of the thermal imaging cameras makes it possible to eliminate of the signal received the information due to ambient light. The periodic recalibration procedure with a calibrated temperature source also makes it possible to avoid the effect of a background noise of, for example, the radiation of a sunny panel near the detection device. The calculator also removes temperature information which only corresponds to a few measurement points, ie corresponding to a heat source having a volume less than a threshold volume such as the end of a cigarette. It is the same for temperature values above a ceiling temperature for example of 42 ° C and whose origin does not correspond to a human fever. When an individual passes through the preferred zone 12 or the mesh zone, the places of the body that are likely to emit thermal radiation are preferably those in the open air, in particular the face and the nape of the neck. The fact that the privileged zone 12 covers, for example, a height of 1.45 m up to 2 m makes it possible to detect the probable zones of maximum heat of an individual, and this without having to recalibrate the device between two individuals. 9, after filtering the temperature information not corresponding to human fever, that is to say, issued in a volume less than a threshold volume or whose temperature is above a ceiling temperature, the computer selects the maximum temperature detected in the area privileged 12. This information is then representative of the body temperature of the individual.

The display mode can be the display of said maximum temperature, an operator using the access control device can then make the decision to intercept the individual or not.

Advantageously, a calibration phase on a representative male, female and children population made it possible to establish the difference between the maximum temperature measured by the device and the actual intracorporeal temperature of the individual in question. The visualization system can automatically correct the displayed information.

According to another variant, the green lamp of the indicator 10 comes on when the maximum temperature received by the computer 9 after filtering and after correcting the previous offset corresponds to an intracorporeal temperature of 37 ° C. The orange lamp comes on when the maximum temperature received by the computer after the various corrections corresponds to a temperature of 38 ° C and the red lamp is lit from an information corresponding to an intracorporeal temperature of 39 ° C or any other temperature decided as being the threshold of abnormality to be detected. It is desirable for the measurement points 8 to cover a sufficiently restricted area, less than 10 ° of angle, or less than a few cm ² , and preferably less than 50 mm ² to identify a hot spot such as an eye or a nose, without the perceived thermal radiation being averaged with those from a too vast area. The access control method is all the more effective when the individuals to be checked are not entirely covered with clothes. In one variant of the process, the temperature of the room in which the individuals to be controlled is raised to a temperature of, for example, 23 °, encourages the individuals to undress, at least headwear, and makes the abnormal temperature detection more effective.

According to a variant of the method, the computer resets all the temperature information it receives as soon as it detects a set of continuous measuring points has descended below a threshold temperature corresponding to the situation of the end of a passage of an individual. This automatically detects the succession between two individuals. According to another variant, the device comprises thermal and / or non-thermal presence sensors. When no individual 3 is in the passage space 4, the device is in the standby configuration, the servomotors 7 are not activated, the consumption is reduced and the device is silent, however the presence sensors remain active and allow triggering the tilting of the device in fine detection configuration as soon as an individual enters the passage space 4.

The access control device may be transposed to other types of warm - blooded individuals and may be used to control the access of animals in the event of an outbreak of foot - and - mouth disease, or to monitor animals in a zoo. . The value of the ceiling temperature, the threshold volume, the temperature difference between the maximum perceived temperature and the intracorporeal temperature, the temperature threshold representative of an abnormality to be detected, the size of the passage space, the height of the zone privileged 12, the depth of field of the focusing systems, are transposable depending on the type of individuals.

Claims

1. Access control device comprising amounts defining a passage space (4) one by one of a line of individuals (3), characterized in that it comprises a sensor assembly able to measure without contact the temperature of a plurality of measurement points (8) distributed in the passage space (4), a calculator (9) able to receive temperature information from each of the measurement points (8) and to calculate as a function of parameters contained in a memory information about the body temperature of the individual (3), and a means for viewing (10) said information.

2. Device according to claim 1, wherein the sensor assembly (6) comprises at least one focusing system (14) defining a detection direction (7) and for each measuring point (8), an element (13). responsive to thermal radiation in said detection direction (7).

3. Device according to claim 2, wherein the passage space (4) comprises at least one privileged zone (12) in which two neighboring measuring points (8) are detected by at least two thermal imaging cameras (6) according to minus two directions of detection

(7) forming an angle between them.

4. Device according to any one of claims 1 to 3, wherein the sensor assembly comprises at least one thermal camera with bar (6) provided with a plurality of photodiodes (13), a focusing system (14). ) corresponding to the plurality of photodiodes (13), a plurality of measuring points (8) aligned according to a measuring segment (16) perpendicular to a general direction of detection (15).

5. Device according to claim 4, wherein the thermal camera bar (6) is provided with a servomotor (17) adapted to rotate the measuring segment (16) around the general direction of detection (15).

6. Device according to claim 4 or 5, wherein the sensor assembly comprises at least one row (5, 5a) of thermal imaging cameras with bars (6) of substantially parallel detection directions (15) and whose measurement segments together form a mesh of a mesh zone (12) of the passage space

(4).

7. Device according to any one of the preceding claims, comprising a calibrated temperature source whose temperature is measured by at least one measuring point (8) of the sensor assembly.

8. Device according to any one of the preceding claims, wherein the distance between two measuring points (8) is greater than 1 cm.

9. Device according to any one of the preceding claims, wherein the sensitivity wavelength of the sensor assembly is between 2 and 22 micrometers.

10. Device according to any one of the preceding claims, wherein the sensor assembly is able to measure the temperature of the measuring points (8) with a sensitivity less than 0.5 ⁰ C when the temperature of said points (8) is between

34 ⁰ C and 42 ° C.

11. Apparatus according to any one of the preceding claims, wherein the computer is adapted to eliminate the temperature information corresponding to a heat source passing through the passage space (14) and whose volume is less than a threshold volume or whose temperature is above a ceiling temperature.

12. Device according to any one of the preceding claims, having a standby configuration and a fine detection configuration, a trigger device being able to move the device from one configuration to the other and comprising a non-presence sensor. -thermal.

13. An access control method in which one by one of the individuals is controlled, characterized in that contactless measurement is performed. temperature of a plurality of measuring points (8), information about the body temperature of the individual as a function of parameters is calculated, and the information is visualized.

The method of claim 13, wherein the parameters include a ceiling temperature, and the body temperature information is the highest measured temperature among those below the ceiling temperature.

The method of claim 13 or 14, wherein displaying the information comprises actuating an indicator (10) when the body temperature information is greater than a threshold of abnormality.

16. The method of claim 13, wherein the temperature of the room where are located the individuals (3) to be controlled at a temperature of at least 23 ° C to cause said individuals (3) to undress.

17. The method of claim 13 or 14, wherein the succession of two individuals (3) is detected.