EP1282885B1 - System for counting living beings - Google Patents

Abstract

A system for counting living beings moving on a first surface (0) and passing through a second cylindrical surface with substantially vertical generatrix, consists of N thermal radiating detection cells (11) having in particular a thermopile (30) including at least a sensitive element (31), and elements focusing (34) the thermal radiation and generating a field of vision (111) extended along a direction, the N detection cells (11) being distributed between two curves, one of the curves coinciding with the base line of the cylindrical surface crossed by the living beings, and the other curve being distant from the former one by a length D (42) equal to 5 cm at least, the direction of the extension of the field of vision of each cell being substantially tangent to one of the two curves.

Description

The object of the invention is a counting system of living beings, moving on a first surface and passing through a second cylindrical surface of a generator substantially vertical. Such a system consists of a set of N cells of detection of thermal radiation and an electronic device for acquiring and treatment of the signals delivered by these cells.

Numerous systems for counting living beings in motion based on the detection of thermal radiation.

The international application WO 9210812 describes such a counting system, using a single cell that has a sensor and a lens positioned in front of it. This sensor is composed of two rows of pyroelectric detectors. The lens focuses the thermal radiation on each of the detectors. This type of radiation detector temperature can only detect relatively rapid changes in temperature in the field of vision. The cell creates two parallel surveillance plans formed by the axes of the beams associated with the detectors. After acquiring electrical signals delivered by the detectors, a treatment unit evaluates the number of living crossing both planes and their directions of movement. This device is adapted to counting in low and low width passages, bus door example. This device is practically unusable in wide passages important given the divergence of the field of view of the sensor. In addition, the use of pyroelectric detectors as part of this application International makes it difficult to detect living things in slow motion.

US Patent 4,799,243 describes another system of counting living beings in movement. This system consists of cells, each cell comprising two thermal radiation detectors and a lens. These two detectors create for each cell two disjoint fields of vision, substantially symmetrical with respect to the vertical. The arrangement of the cells as provided for in this patent is chosen for cover the entire width of the passage to be monitored with a covering of the fields vision in a direction perpendicular to the direction of crossing and a separation of fields of vision according to the direction of crossing. Such an arrangement does not allow the counting living beings too close to each other according to the direction of crossing.

US Pat. No. 5,068,537 describes another system for counting living creatures in movement using a large number of cells arranged on a single line. The system is designed so that a medium-sized living being is detected by at least two cells. Since each cell has only one detector, the system does not allow the determination of the direction of crossing counted living beings.

Another living count system is described in DE 4220508.

In the counting system of living beings which is the subject of the invention, the detectors of thermal radiation used are thermopiles that are characterized by their ability to detect even very slow variations of temperature in their field of vision.

The counting system for living beings that is the subject of the invention comprises a set of N thermal radiation detection cells and an electronic device acquisition and processing of the signals delivered by these cells. Each cell comprises in particular a thermopile comprising at least one sensitive element, a medium focusing the thermal radiation on the sensitive elements of this thermopile, this focusing means creating an elongated field of view according to a direction, a mask limiting this field of view and an amplifier of the signal delivered by the thermopile. In the counting system of living beings, object of the invention, the N detection cells are equidistributed according to two curves when N is even and are divided along two curves with a difference of one unit when N is odd, the distribution of the cells on each curve being uniform according to an identical pitch P for each of the two curves, one of these curves identifying with the director of the surface cylindrical crossed by living beings, and the other curve being distant from the preceding of a length D equal to at least 5 cm, the direction of elongation of the field each cell being substantially tangent to one of the two curves.

A filter generally placed in the thermopile in front of the sensitive element limits the sensitivity to thermal radiation of bodies near temperature ambient, which corresponds to far-infrared radiation in the wavelengths of about 7 to 14 μm. The means of focusing of each cell is adapted to the number, arrangement and geometry of the sensitive element (s) of the thermopile so as to create an elongated field of view in one direction and as narrow as possible in the direction perpendicular to the previous one. The means of focusing is preferably carried out using one or more lenses. he can possibly be made by pinhole or mirror. According to the invention, a single lens, preferably when the thermopile comprises a single sensitive element of elongated surface or when the thermopile has an alignment of sensitive elements whose surfaces have dimensions substantially similar in two directions orthogonal. According to the invention, several lenses are used, preferably when the thermopile has only one sensitive element whose surface has dimensions substantially adjacent in two orthogonal directions.

In the systems that are the subject of the invention, it is advisable to choose a distribution pitch P detection cells close to the width of a living being statistically representative beings of minimal size belonging to the population to count. When it comes to counting human beings this pitch P is substantially equal to 45 cm.

More particularly, the system which is the subject of the invention is used to count beings living through a plane; in this case, the curves on which the cells are distributed are parallel lines.

The opening of the field of view, according to the direction of extension of this field, can be chosen for each cell belonging to the same line, so as to ensure the juxtaposition of the zones seen by two successive cells on the same line, to a height close to the minimum size of a living being statistically representative of beings belonging to the population to count.

When in addition it is a question of counting human beings crossing a plane, it is opportune to design the system object of the invention so that the extent of the area seen by each cell at a height of 1 m and measured according to the alignment is substantially equal at 45 cm.

The counting system for living beings which is the subject of the invention comprises a device electronic signal processing system delivered by the cells that operates a algorithm. A first task of this algorithm initializes the parameters specifying the system configuration. A second task of this algorithm ensures successively for each cell the reading and the processing of the numerical values delivered by the electronic device of acquisition. A third task of this algorithm ensures the adaptation of the sensitivity threshold of the cells. A fourth task of this algorithm analysis for all couples of successive cells the information from the second task. A fifth task of this algorithm analyzes the results of the fourth task and deduces the counting of living beings, their sense of crossing and their movement speed. A sixth task of this algorithm exploits counting as well obtained according to the intended application. A seventh task of this algorithm manages the rate of execution of the preceding tasks according to the sampling frequency of the signals delivered by the cells. In counting systems of living beings subject to the invention, the fifth task of the algorithm can be conceived in such a way that allow the grouping, as entities, of successive cell pairs for which the information from the fourth task of the algorithm corresponds crossing a living being or a group of living creatures, information from couples of each entity specifying this number of living beings, the meaning of their crossing and the speed of their movement.

The counting system of living beings which is the subject of the invention offers various advantages by compared to known systems and in particular its easy integration for any width of passage to watch; its excellent counting performance even for a low passage height; its adaptability of implantation in environments individuals; its ability to count dense crowds and moving living things slow.

The counting system of living beings which is the subject of the invention can be described as a non with the following example illustrated in FIGS. 1 to 14. This example corresponds to counting human beings crossing a plane, using eight cells equidistributed on two straight lines.

FIG. 1 schematically represents a system that is the subject of the invention comprising eight cells arranged in two alignments.

Figures 2a and 2b show two views of a radiation detection cell thermal system used in the system shown schematically in Figure 1.

Figure 3 shows a network of Fresnel lenses used in the cell shown at Figures 2a and 2b.

Figures 4a and 4b show the cell shown in Figures 2a and 2b with its field of vision.

FIGS. 5a and 5b show two views, in two orthogonal directions, of a group of two successive cells, each belonging to an alignment different, as well as the fields of view of these cells.

FIG. 6a represents, in plan view, five successive cells belonging to the system shown in Figure 1.

FIGS. 6b and 6c represent, in plan view, the zones seen by the five cells schematically in Figure 6a, respectively at 1 m and at ground level.

FIGS. 7a to 7e show, in plan view, five successive phases of the crossing of a human being perpendicular to the cell alignments and for a representation of the zones seen according to FIG. 6b.

FIG. 7z schematizes the temporal evolution of the signals delivered by the thermopile of each cell, for the crossing defined by FIGS. 7a to 7e.

FIGS. 8a to 8e show, in plan view, five successive phases of the crossing a human being obliquely to the cell alignments and for a representation of the zones seen according to FIG. 6b.

FIG. 8z schematizes the temporal evolution of the signals delivered by the thermopile of each cell, for the crossing defined by Figures 8a to 8e.

Figure 9 shows the chronological sequence, in the form of a flowchart, of different tasks of processing electrical signals, delivered by the cells.

Figures 10, 11, 12 and 13 show four particular tasks in the flowchart shown in Figure 9.

Figure 14 shows the table used by the particular task shown in Figure 13.

Figure 1 shows the ground 0, a set of eight radiation detection cells distributed in two alignments, a first alignment 1 comprising four cells 11; 12; 13; 14, a second alignment 2 comprising four cells 21; 22; 23; 24, two human beings 4 and 5, an electronic device 6 for acquiring and digitization of the signals delivered by the cells, these signals possibly being at the cell level, an electronic device 7 for processing digital values delivered by the acquisition device 6, an operating device 8 information from the processing device 7, a medium 3 connecting all the cells to the acquisition device 6. The eight cones 111 to 114 and 121 to 124 schematize the fields of view of each of the cells. The intersections of these cones with a plane parallel to the ground 0 and located at a height of 1 m define the areas seen at this height and are schematized by the eight ellipses 211 to 214 and 221 to 224.

Figure 2a is a schematic section of a cell in a plane perpendicular to two cell alignments.

Figure 2b is a schematic section of the same cell, orthogonal to the section shown in Figure 2a.

This cell comprises a thermopile 30 whose sensitive element 31 provides a signal small amplitude proportional to the thermal radiation received through of the infrared filter 32, a signal amplification and shaping stage 33 delivered by the thermopile 30, a device 38 connecting the amplification stage and shaping 33 to medium 3, a network of Fresnel lenses 34 away focal length 40, placed at a distance equal to this focal length 40 in front of the sensitive element 31 of the thermopile 30, a mask 35 placed in front of the Fresnel lens array 34 and a waterproof housing 36, opaque to electromagnetic radiation and whose surface Inner absorbs thermal radiation. The Fresnel Lens Network 34 has eight elements 34a to 34h.

Figure 3 shows the Fresnel lens array 34. This network is composed of eight elemental Fresnel lenses 34a to 34h. These lenses are juxtaposed and their centers optics are aligned along the line 39.

FIGS. 4a and 4b show the cell shown in FIGS. 2a and 2b according to the same projections. These figures show the elementary fields of vision 37c, 37d, 37e and 37f associated with unmasked elemental Fresnel lenses 34c, 34d, 34e and 34f.

FIGS. 5a and 5b show successive cells 11 and 21 as well as their fields 111 and 121 respectively. These two cells belong to a different alignment.

Figure 5a shows the fields of view perpendicular to the direction of travel normal human beings. Figure 5b shows the fields of view in the sense of normal movement of human beings.

The view represented in FIG. 5a highlights the weak opening of the fields of vision 111 and 121 as well as the short distance D 42 between the two alignments 1 and 2.

The view represented in FIG. 5b highlights the important opening of the fields of 111 and 121 as well as the half P / 2 step 41 between these cells.

Figure 6a shows a top view of the five cells 11; 21; 12; 22; 13 disposed along the two alignments 1 and 2 distant from the distance D 42. This view also shows the half-pitch P / 2 41 between two successive cells.

Figure 6b shows in plan view the arrangement of the zones 211; 221; 212; 222; 213 viewed at a height of 1 m above ground level 0 and corresponding respectively cells 11; 21; 12; 22; 13. This figure 6b highlights the juxtaposition of zones seen by two successive cells arranged on the same alignment.

FIG. 6c shows in plan view the arrangement of the zones seen at ground level 0, 311; 321; 312; 322; 313 respectively corresponding to the cells 11; 21; 12; 22; 13. This figure 6c highlights the partial superposition of the zones seen by two successive cells arranged on the same alignment.

FIGS. 7a to 7e respectively represent, in plan view, five phases successive a, b, c, d, e crossing a human being 4 perpendicular to the alignments 1 and 2, as well as the areas seen at a height of 1 m above the level of the ground, shown in Figure 6b. Figure 7z shows the waveforms of the signals electric 411; 421; 412; 422; 413 delivered respectively by the cells 11; 21; 12; 22; 13. The level of each electrical signal 411; 421; 412; 422; 413 is related to the fraction of the view area occupied by the human being that crosses the fields of view of cells 11; 21; 12; 22; 13.

In phase a, the human being 4 is not present in any of the zones 211; 221; 212; 222; 213. Electrical signals 411; 421; 412; 422; 413 shown in the figure 7z have a zero level.

In phase b, the human being 4 completely occupies the view area 212. The signal level 412 is maximal. The human being 4 occupies very partially the zone seen 213. The level signal 413 has a peak of very low amplitude. The zones viewed 211; 221; 222 does not are not occupied by the human being 4. The levels of the corresponding signals 411; 421; 422 remain void.

In phase c, the human being 4 continues to occupy the entire area 212. signal level 412 remains maximum. Human being 4 partially occupies the views 221 and 222. The level of the signals 421 and 422 is average. The zones seen 211 and 213 do not are not occupied by the human being 4. The corresponding signal levels 411 and 413 remain void.

In phase d, the human being 4 leaves the view area 212. The signal level 412 becomes zero again. The human being 4 continues to occupy partially the zones seen 221 and 222. The level of the signals 421 and 422 remains average. The zones seen 211 and 213 are not not occupied by humans 4. Corresponding signal levels 411 and 413 remain void.

In phase e, the human being 4 leaves the zones seen 221 and 222. The level of the signals 421 and 422 become void again. The zones viewed 211; 212; 213 are not occupied by being human 4. Levels of corresponding signals 411; 412; 413 remain void.

Since all the signal levels are zero, the human being 4 will be able to be counted with discrimination of the crossing direction of alignments.

FIGS. 8a to 8e respectively represent, in plan view, five phases successive a, b, c, d, e of the crossing of a human being obliquely to the alignments 1 and 2, as well as the areas seen at a height of 1 m above ground level, shown in Figure 6b. FIG. 8z schematizes the oscillograms of the electrical signals 511; 521; 512; 522; 513 issued respectively by the cells 11; 21; 12; 22; 13. The level of each electrical signal 511; 521; 512; 522; 513 is related to the fraction of the view area occupied by the human being which passes through the fields of view of the cells 11; 21; 12; 22; 13.

In phase a, the human being is not present in any of the zones seen 211; 221; 212; 222; 213. Electrical signals 511; 521; 512; 522; 513 shown in the figure 8z have a zero level.

In phase b, the human being 5 partially occupies the zones 212 and 213. signal level 512 and 513 is average. The zones viewed 211; 221; 222 are not occupied by the human being 5. Levels of the corresponding signals 511; 521; 522 are zero.

In phase c, the human being occupies almost entirely the area viewed 212. The level signal 512 reaches a maximum. The human being 5 partially occupies the views 221 and 222. The level of the signals 521 and 522 is average. The zones seen 211 and 213 do not are not occupied by the human being 5. The levels of the corresponding signals 511 and 513 remain void.

In phase d, the human being 5 leaves the zones seen 212 and 222. The level of the signals 512 and 522 becomes zero again. The human being occupies the entire zone 221. signal 521 reaches a maximum. The views 211 and 213 are not occupied by 5. The levels of the corresponding signals 511 and 513 remain zero.

In phase e, the human being leaves the view zone 221. The level of the signal 521 becomes again no. The zones viewed 211; 212; 213; 222 are not occupied by humans. corresponding signal levels 511; 512; 513; 522 remain void.

Since all the levels of the signals are zero, the human being 5 will be able to be counted with discrimination of the crossing direction of alignments.

Figure 9 shows the chronological sequence, in the form of a flowchart, of different tasks of real-time processing of numerical values from the device electronic 6 acquisition and digitization of electrical signals 411; 421; 412; 422; 413, delivered by the five cells 11; 21; 12; 22; 13. This chart is put implemented by the electronic device 7. The flow chart of Figure 9 has a point 601 and an exit point 699. It has seven tasks 603; 700; 800; 900; 1000; 605; 607.

Task 603 allows the initialization of parameters specifying the configuration of the system Count: number of cells, height of cells relative to the ground, not P and distance D as well as processing parameters: sampling frequency of electrical signals delivered by the cells and initial sensitivity threshold of the cells. The task 603 sets the cells to the INVALID stored state as well as the pairs of successive cells, that is to say the pairs such as the pair 11; 21 followed by a couple 21; 12, himself followed by the pair 12; 22 and so on, in the stored state INVALID.

Task 700 provides successively for each cell the reading and processing of digital values delivered by the electronic device 6.

The task 800 ensures for the system object of the invention the adaptation of the threshold of cell sensitivity used by task 700.

The task 900 analyzes for all the successive pairs of cells, the information from task 700.

The task 1000 analyzes the results of the task 900 and deduces the count of the beings humans.

The task 605 allows the operation by the electronic device 8, of the metering carried out by the task 1000, depending on the intended application.

Task 607 manages the execution rate of tasks 700 to 605 according to the frequency sampling; this task 607 is executed at each instant (t). To this end, the task 607 delays connection 607/1 to task 700. Task 607 also allows to definitively leave the execution of the tasks 700 to 605 by the connection 607/0 towards the exit point 699.

For the execution of tasks 700, 800, 900 and 1000, an index k is associated with each cell. The value 1 of the index k is associated with an extreme cell, 11 for example; the value 2 of the index k is associated with the successive cell, here the cell 21, and so on.

In the same way, an index m is associated with each pair of successive cells. The value 1 of the index m is associated with an extreme pair, 11; 21 for example; the value 2 of the index m is associated with the successive pair, here the pair 21; 12, and so on.

Figures 10, 11, 12 and 13 show respectively in the form of flowcharts the chronological sequence of the elementary tasks constituting the tasks 700; 800; 900 and 1000.

In Fig. 10, entry point 701 and exit point 799 of task 700 are shown. This task repeats for each digital value delivered by the electronic device 6 elementary tasks 705 to 719.

The task 703 initializes to 1 the index k associated with the cell which is read and whose numerical value.

Task 705 controls the acquisition and digitization by the electronic device 6 the electrical signal delivered at the instant (t) by the cell in question.

Task 707 handles the processing of the numerical value delivered by task 705 in order to homogenization of all the digital values of the delivered signals.

The task 709 stores the value processed by the task 707 if it corresponds to a local maximum, determined from values previously processed by task 707 for this cell. The value stored by task 709 is used for adaptation in the task 800 of the sensitivity threshold of the cells.

The test 711 verifies the superiority of the value processed by the task 707 on the threshold of sensitivity of the cells.

Connection 711/1 is effective if test 711 is TRUE; in this case a human being is in the field of view of the cell in question.

The task 712 stores the value processed by the task 707 and the instant (t); she positions the cell considered in the instantaneous ACTIVE state.

The 711/0 connection is effective if the test 711 is FALSE.

The test 713 verifies the superiority of the value processed by the task 707 on the threshold of cell sensitivity, at the previous instant (t-1).

Branch 713/1 is effective if test 713 is TRUE; in this case a human being just left the field of view of the cell in question; task 715 analyzes the successive values stored by the task 712 to extract information Characteristics of the crossing of a human being: moment of beginning of the crossing, instant end of the crossing, instant corresponding to the median of the stored values and average of these values; it positions the cell in the stored state VALID. All this information is stored for analysis by task 900.

The 713/0 connection is effective if the test 713 is FALSE; in this case, no being human being is in the field of view of the cell considered.

The task 714 positions the cell in the instantaneous PASSIVE state.

Task 717 increments the index k associated with a cell.

The test 719 verifies that the new index k is less than or equal to the total number of cells.

Branch 719/1 is effective if test 719 is TRUE; in this case all the cells have not been processed and go back to task 705.

The 719/0 connection is effective if the test 719 is FALSE; in this case all the cells have been treated.

In Fig. 11, entry point 801 and exit point 899 of task 800 are shown.

This task has two elementary tasks 803 and 805 ensuring the adaptation of the threshold of sensitivity of the cells according to the last V values memorized by the task 709 of Figure 10; V being chosen arbitrarily according to the application, by example depending on the frequency of crossing of living beings or according to a fixed number of crossings; this number can be chosen in the range from 20 to 100.

The 803 test checks that all the cells are in the PASSIVE instant state and that minus V values have been stored by task 709 of task 700.

The 803/1 connection is effective if the 803 test is TRUE; in this case, the threshold of Cell sensitivity can be adapted.

Task 805 calculates the rolling average over all last V values memorized by the task 709 of FIG. 10 and deduces therefrom the new sensitivity threshold cells.

The 803/0 connection is effective if the 803 test is FALSE; in this case the threshold of Cell sensitivity can not be adapted.

In Fig. 12, entry point 901 and exit point 999 of task 900 are shown. This task repeats elementary tasks 905 to 911 for each pair of cells. analyzes the extracted characteristic information for each cell by task 700 and deduces the characteristic information of each couple.

The task 903 initializes to 1 the index m associated with the pair of cells to be analyzed.

The test 905 verifies that the two cells forming the couple considered are in the state memorized VALID and that there is a period of common occupation during which the human being is simultaneously in the field of vision of the two cells, which amounts to to consider that the human being is in the field of vision of the couple.

The 905/1 connection is effective if the 905 test is TRUE.

Task 907 analyzes the extracted characteristic information for each cell of the couple of successive cells considered and deduces the characteristic information of the crossing of a human being for this couple: moment of beginning of common occupation, moment of end of common occupation, average of the couple, that is to say average of the averages calculated for the couple's cells, signature of the occupation chronology couple cells; the state of the pair of successive cells is considered as VALID. The signature of the chronology of occupation of the cells of the couple is chosen arbitrarily POSITIVE if the human crosses the alignment 1 then the alignment 2 and NEGATIVE if the human crosses the alignment 2 then the alignment 1.

The 905/0 connection is effective if the 905 test is FALSE.

Task 909 increments the index m associated with a pair.

The 911 test verifies that the new index m is less than or equal to the total number of couples.

The 911/1 connection is effective if the 911 test is TRUE; in this case all couples have not been analyzed and we return to the 905 test.

The 911/0 connection is effective if the 911 test is FALSE; in this case all couples have been analyzed.

In Figure 13, we see the entry point 1001 and the exit point 1099 of the task This task repeats for each pair of cells the elementary tasks 1005 to 1017 to analyze the extracted characteristic information for each pair during the task 900 as well as the extracted characteristic information for each cell during task 700. This analysis makes it possible to construct entities consisting of either a isolated couple whose state is VALID, that is, successive pairs whose state is VALID and for which there is a lapse of time during which one or more human beings are simultaneously in their field of vision. More precisely, an entity is characterized by an X number of couples whose signature of the chronology of occupation is POSITIVE as well as by a number Y of couples whose signature the chronology of occupation is NEGATIVE. The analysis of these characteristic numbers of the entity makes it possible to determine in real time the number of human beings associated with this entity and their direction of passage, according to a rule specified in Figure 14.

The task 1003 initializes to 1 the index m associated with the pair of cells to be analyzed and initialises to zero the contents of the entity, which means that the entity contains no couple.

The test 1005 verifies that the couple considered is in the VALID state.

The 1005/0 connection is effective if the 1005 test is FALSE.

Task 1006 resets the contents of the entity to zero, which means that the entity does not contains no couple.

The 1005/1 connection is effective if the 1005 test is TRUE.

Task 1007 includes the couple considered in the entity.

Test 1009 verifies that there is a period of time during which one or more beings humans are in the field of view of the couple considered and the next couple.

The 1009/0 connection is effective if the 1009 test is FALSE; in this case, the entity is complete, it can be analyzed to count human beings.

Task 1011 uses the table shown in Figure 14 to analyze the entity and to determine in real time the number of human beings and their direction of passage.

Task 1013 updates the characteristic information of couples and cells contained in the entity and then re-initializes the content of the entity to 0. The state of these couples and the stored state of these cells are repositioned in the INVALID state.

The 1009/1 connection is effective if the 1009 test is TRUE; in this case, the couple next is likely to be included in the entity.

Task 1015 increments the index m associated with a pair.

Test 1017 verifies that the new index m is less than or equal to the total number of couples.

Connection 1017/1 is effective if test 1017 is TRUE; in this case all couples have not been analyzed and we return to the 1005 test.

The 1017/0 connection is effective if the test 1017 is FALSE; in this case all couples were analyzed.

Figure 14 shows the characteristic number analysis chart of the created entity during task 1000. This array has as many columns and rows as there are cells in the system. This table defines the number of human beings associated with the entity as well as their direction of crossing according to the characteristic numbers of the entity. The column numbers correspond to the possible values taken by the number X and the line numbers correspond to the possible values taken by the number Y. The empty boxes in the table correspond to impossible situations; the other boxes of the array include either a letter or at least one signed integer whose module represents the number of human beings counted and whose sign corresponds to the crossing initial alignment 1 if it is positive and at the initial crossing of alignment 2 if it is negative

The letters A, B and C of the table correspond to the special cases for which the counting of human beings is conditioned by additional information.

The letter A is to be replaced by (+1) when the average of the couple having the signature POSITIVE is greater than the average of the couple with the NEGATIVE signature.

The letter A is to be replaced by (-1) when the average of the couple having the signature POSITIVE is less than the average of the couple with the NEGATIVE signature.

The letter B is to be replaced by the set (+1) & (-1) when the couple having the POSITIVE signature was included in the entity before or after the other pairs and by (-2) in other cases.

The letter C is to be replaced by the set (+1) & (-1) when the couple having the NEGATIVE signature was included in the entity before or after the other couples and by (+2) in other cases.

Claims (10)

1. A system for counting living beings moving on a first surface (0) and passing through a second cylindrical surface with a substantially vertical generatrix, consisting of a set of N thermal radiation detection cells (11) and an electronic device for acquiring and processing signals delivered by these cells, characterized in that each of these cells comprises a thermopile (30) comprising at least one sensitive element (31), a means (34) focusing the thermal radiation on the sensitive elements of this thermopile, this focusing means creating an elongate field of vision (111) in one direction, a mask (35) limiting this field of vision and an amplifier for amplifying the signal delivered by the thermopile (30) and characterized in that the N detection cells (11) are equally distributed between two curves when N is even and are distributed between two curves with a difference of one when N is odd, the distribution of cells over each curve being uniform along a pitch P which is identical for each of the two curves, one of these curves being identified with the directrix of the cylindrical surface through which the living beings pass, and the other curve being distant from the former one by a length D (42) equal to at least 5 cm, the elongation direction of the field of vision of each cell being substantially tangent to one of the two curves.
2. The system for counting living beings as claimed in claim 1, characterized in that the means (34) of focusing each cell is produced with a single lens and in that the thermopile comprises a single sensitive element with an elongate surface or an alignment of sensitive elements, the surfaces of which have substantially similar dimensions in two orthogonal directions.
3. The system for counting living beings as claimed in claim 1, characterized in that the means (34) of focusing each cell is produced using several lenses and in that the thermopile comprises only a single sensitive element, the surface of which has substantially similar dimensions in two orthogonal directions.
4. The system for counting living beings as claimed in claim 1, characterized in that the pitch P is chosen close to the width of a living being statistically representative of beings of minimum size belonging to the population to be counted.
5. The system for counting living beings as claimed in claim 4, characterized in that the pitch P is substantially equal to 45 cm and that the system is adapted for counting human beings.
6. The system for counting living beings as claimed in claim 1, characterized in that the cylindrical surface through which the living beings pass is a plane, the curves along which the cells are distributed being parallel straight lines.
7. The system for counting living beings as claimed in claim 6, characterized in that the aperture of the field of vision (111), in the elongation direction of this field, is chosen for each cell belonging to the same straight line, so as to juxtapose zones (211)(212) seen by two successive cells (11)(12) on the same straight line (1), at a height close to the minimum size of a living being statistically representative of beings belonging to the population to be counted.
8. The system for counting living beings as claimed in claim 7, characterized in that the extent of the zone seen by each cell at a height of 1 m and measured along the alignment is substantially equal to 45 cm and that the system is adapted for counting human beings.
9. The system for counting living beings as claimed in claim 1, characterized in that the electronic device (7) for processing signals delivered by the cells exploits an algorithm, a first task (603) of which initializes the parameters specifying the configuration of the system, a second task (700) of which reads and processes the digital values delivered by the electronic acquisition device successively for each cell, a third task (800) of which adapts the cell sensitivity threshold, a fourth task (900) of which compares the information from the second task (700) for all the pairs of successive cells, a fifth task (1000) of which analyzes the results of the fourth task (900) and deduces therefrom the count of living beings, their direction of crossing and their speed of movement, a sixth task (605) of which exploits the count thus obtained as a function of the envisioned application and a seventh task (607) of which manages the rate of execution of the previous tasks depending on the frequency of sampling of the signals delivered by the cells.
10. The system for counting living beings as claimed in claim 9, characterized in that the analysis carried out by the fifth task (1000) of the algorithm brings together, in the form of entities, pairs of successive cells for which the information from the fourth task (900) corresponds to the crossing of a living being or of a group of living beings, the information of the pairs of each entity specifying this number of living beings, the direction of their crossing and the speed of their movement.

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