DEVICE AND METHOD FOR DISTINGUISHING AND COUNTING PERSONS AND OBJECTS

Abstract

The invention relates to a method for distinguishing, detecting and counting persons and/or objects in vehicles for conveying persons and/or goods, with the method steps: emitting radiation from a radiation source, deflecting the radiation with an element for deflecting the radiation, generating a light pattern in a detection region with a beam density ρ.sub.s of 5*10.sup.2/4*πsr.sup.−1≤ρ.sub.s≤10.sup.6/4*πsr.sup.−1, and detecting the radiation backscattered by persons and/or objects situated in the detection region in a radiation detector, as well as a corresponding person and/or object counting device.

Claims

1. A method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities (160) and/or vehicles for conveying persons and/or goods, with the following method steps: Emitting radiation (S) from a radiation source (10) Deflecting the radiation (S) with an element for deflecting the radiation (30) Generating a light pattern (50) in a detection region (40) with a beam density ρ.sub.s of 5*10.sup.2/4*πsr.sup.−1≤ρ.sub.s≤10.sup.6/4*πsr.sup.−1 Detecting the radiation (S) backscattered by persons and/or objects situated in the detection region (40) in a radiation detector (20).

2. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that a light pattern (50) is detected in the detection region (40).

3. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 2 characterized in that the movement of the light pattern (50) is detected in the detection region (40).

4. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 3 characterized in that the shift of the light pattern (50) is detected in the detection region (40).

5. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 4 characterized in that the length of the shift is calculated.

6. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 5 characterized in that a depth value to determined from the length of the shift.

7. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 6 characterized in that the detected, synchronously shifted light patterns (50) are compared with characteristic known patterns.

8. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 2 characterized in that the light pattern (50) is assigned to an object type.

9. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 8 characterized in that a characteristic point is determined for the assigned light pattern (50).

10. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 9 characterized hi that the characteristic point is determined with the aid of the center of gravity method.

11. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that a counting event is triggered when the light pattern (50) and/or the characteristic point touches a counting region (70).

12. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 11 characterized in that the counting region (70) comprises a volume which is defined in space and is at least partially part of the detection region.

13. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 12 characterized in that the counting region (70) comprises an area (80) which is defined in space and intersects the detection region.

14. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that the direction of movement of the light pattern and/or of the abstracted point is detected.

15. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 14 characterized in that the counting event is classified using the direction of movement of the light pattern (50) and/or of the abstracted point.

16. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that the method is suitable for distinguishing, detecting and/or counting persons and objects in vehicles for conveying persons and/or goods.

17. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that the generated beam density ρ.sub.s is in at least 1*10.sup.3/4*πsr.sup.−1, preferably 5*10.sup.3/4*πsr.sup.−1 and particularly preferably 1*10.sup.4/4*πsr.sup.−1.

18. The method for distinguishing, detecting and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 1 characterized in that the generated beam density ρ.sub.s is in maximally 5*10.sup.5/4*πsr.sup.−1, preferably 1*10.sup.5/4*πsr.sup.−1 and particularly preferably 5*10.sup.4/4*πsr.sup.−1.

19. A person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying passenger and/or goods, comprising: a radiation source (10), a radiation detector (20), an element (30) for deflecting the radiation (S) leaving the radiation source (10) wherein the element (30) for deflecting the radiation (S) leaving the radiation source (10) is suitable for generating a light pattern (50) in a detection region (40) with a beam density rs of 5*10.sup.2/4*πsr.sup.−1≤ρ.sub.s≤10.sup.6/4*πsr.sup.−1.

20. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 19 characterized in that the person- and/or object-counting device (1) has an interface (70) to a control and/or evaluation apparatus (60).

21. The person- and/or object-daunting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 19 characterized in that the radiation detector (20) of the person- and/or object counting device (1) is suitable for detecting the radiation of the light pattern (50) backscattered by persons and/or objects in the detection region (40).

22. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 19 characterized in that the person- and/or object-counting device (1) has a control and/or evaluation apparatus (60).

23. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 22 characterized in that the control and/or evaluation apparatus (60) is suitable for executing a program which assigns an object type to the light patterns (50) on the basis of the light patterns (50) backscattered by the persons and/or objects.

24. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 22 characterized in that the control and/or evaluation apparatus (60) is suitable for executing a program which follows the shift of persons and/or objects with regard to their direction and/or length on the basis of the backscattered light patterns (50).

25. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 22 characterized in that the person- and/or object-counting device (1) is suitable for detecting the touching of a light pattern (50) with a counting region (70) situated in the detection region (40).

26. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 25 characterized in that the counting region (70) comprises a volume, the location of which is predefined.

27. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 26 characterized in that the counting region (70) comprises a plane (80), the location of which is predefined.

28. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 27 characterized in that the counting region (70) comprises at least two planes (80, 81), the location of which is predefined.

29. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 25 characterized in that the counting region (70) is arranged in a region between 30 cm in front of and 30 cm behind a door of the vehicle for conveying persons and/or objects.

30. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 29 characterized in that the counting region (70) is arranged in a region between 20 cm in front of and 20 cm behind a door of the vehicle for conveying persons and/or objects and preferably between 10 cm in front of and 10 cm behind the door of the vehicle for conveying persons and/or objects.

31. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 19 characterized in that the generated beam density ρ.sub.s is in at least 1*10.sup.3/4*πsr.sup.−1, preferably 5*10.sup.3/4* πsr.sup.−1 and particularly preferably 1*10.sup.4/4*πsr.sup.−1.

32. The person- and/or object-counting device (1) for detecting, categorizing and counting persons (170) and/or objects (171) in facilities and/or vehicles (160) for conveying persons and/or goods according to claim 19 characterized in that the generated beam density ρ.sub.s is in maximally 5*10.sup.5/4*πsr.sup.−1, preferably 1*10.sup.5/4*πsr.sup.−1 and particularly preferably 5*10.sup.4/4*πsr.sup.−1.

Description

THE FIGURES SHOW

[0061] FIG. 1 Arrangement of the device according to the invention for detecting, categorizing and counting persons and/or objects and location of the detection region.

[0062] FIG. 2 Location of the detection region with generated light pattern.

[0063] FIG. 3 Detection of persons and/or objects in the detection region.

[0064] FIG. 4a Generated 3D point cloud of the persons and/or objects in the detection region.

[0065] FIG. 4b Generated 3D point cloud when the persons and/or objects in the detection region are moving.

[0066] FIG. 5a Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10, point density too low.

[0067] FIG. 5b Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10, point density suitable.

[0068] FIG. 5c Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10, point density suitable.

[0069] FIG. 5d Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10, point density suitable.

[0070] FIG. 5e Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10 point density suitable.

[0071] FIG. 5f Determination of the suitable density of the pattern points of the light pattern generated by the radiation source 10, point density too high.

[0072] FIG. 6 Detection region for detecting, categorizing and counting persons and/or objects of the device for detecting, categorizing and counting persons and/or objects on a door portal.

[0073] FIG. 7a Orientation and location of a counting area on a door portal.

[0074] FIG. 7b Orientation and location of two parallel counting areas on a door portal.

[0075] FIG. 7c Orientation and location of a counting volume on a door portal,

[0076] FIG. 8 Structure of an exemplary embodiment of the device for detecting, categorizing and counting persons and/or objects.

[0077] FIG. 1 shows a typical scene in the region for getting into and getting out of a vehicle for conveying persons, for example a public passenger transportation vehicle. Persons of different body size and thus different volumes characterize this region; in addition, the persons wear different clothing and have different hair colors and hairstyles. There are therefore different in their reflection of light. The persons may also carry objects such as bags, suitcases, bicycles, etc. with them. These persons and the objects are simultaneously detected, categorized and counted by the device according to the invention for detecting, categorizing and counting persons and/or objects 1.

[0078] The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which are connected to one another by means of interfaces 70.

[0079] The device for detecting, categorizing and counting persons and/or objects 1 is situated, in all the exemplary embodiments shown here, in the upper region of the region for getting into and getting out of the vehicle.

[0080] To describe the location of the device for detecting, categorizing and counting persons and/or objects 1 in space, the central projection point of the radiation source 10 is used and the location of the optical axis of the radiation source 10, meaning the straight line which is perpendicular to the element for deflecting the radiation 30 and contains the central projections point. If the elements of the device for detecting, categorizing and counting persons and/or objects 1 are firmly connected to one another, the geometric location of the device for detecting, categorizing and counting persons and/or objects 1 is thus also clearly defined in space. In order to ensure the functionality of the device for detecting, categorizing and counting persons and/or objects 1, the projection point lies between 1.7 m (minimum) and 20 m (maximum) vertically above the floor of the vehicle. In typical vehicles, the projection point lies between 1.8 m to 3 m vertically above the floor of the vehicle.

[0081] To distinguish, detect and count persons and/or objects in vehicles for conveying persons and/or goods, the radiation source 10 of the device for detecting, categorizing and counting persons and/or objects 1 emits radiation S in the first method step. The ambient light can contain sunlight or light from artificial illumination sources. It is therefore to be expected that radiation from the near infrared wavelength range is contained in the ambient light. Such ambient light can overlay the light that is emitted by the radiation source 10. As a solution, monochromatic laser radiation and a spectrally selective detector is used. The wavelength is chosen such that the radiation is invisible to the human eye. When choosing the wavelength, it must be ensured that the image sensor of the radiation detector 20 has a sufficiently high quantum efficiency to generate enough photoelectrons. For the realization of the invention, light of the wavelength from 780 nm to 1000 nm is suitable. The invention thus works reliably under the ambient conditions in the mobile range.

[0082] The laser radiation S is collimated by a lens and guided perpendicularly onto the element for deflecting the radiation 30. The element for deflecting the radiation 30 is usually a diffractive optical element (DOE), which is structured such that, in the second method step for distinguishing, detecting and counting persons and/or objects in vehicles for conveying persons and/or goods, a suitable detection region 40 having a counting area 80 is created behind the DOE 30. In the context of the invention, however, any optical arrangement which generates a light pattern 50 can also be used. In this exemplary embodiment, the counting area 80 is chosen such that it coincides with the door cut-out of the region for getting in and getting out.

[0083] FIG. 2 shows in an exemplary manner the light pattern 50 generated by the radiation source 10 of the device for detecting, categorizing and counting persons and/or objects 1 in the detection region 40. For better illustration, the persons and objects are removed from this representation.

[0084] The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which are connected to one another by means of interfaces 70. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0085] In the third method step for distinguishing, detecting and counting persons and/or objects in facilities and/or vehicles for conveying persons and/or goods, the device for detecting, categorizing and counting persons and/or objects 1 generates a light pattern 50. The projected light pattern 50 consists of small, delimited, illuminated regions and of dark, i.e. non-illuminated, regions. The illuminated regions can be abstracted in a good approximation as light points. The location of the light points can be described assuming the model of light beams originating from a central projection point in the radiation source 10.

[0086] The generation of 3D depth data from a spatial region is central to the invention. In order to obtain such 3D data, the triangulation principle is expanded into the third spatial dimension. In order to obtain clear depth data, the correspondence problem between features of the detected images from the radiation detector 20 and the features that are projected into the space must be solved. The light pattern 50 provides the features required to solve the correspondence problem.

[0087] The light pattern 50 is designed in this case such that the projected light pattern 50 in small image sections along the direction of shift of the persons and/or objects is unique at any possible position.

[0088] The density of the pattern points determines the resolution of the detected persons and objects. Since the pattern points are created through central projection, the number of the light beams per spatial angle is a measure for the resulting point density. The spatial angle Ω is defined as the area content A of a sub-area of a sphere surface, divided by the square of the radius r of the sphere Ω=A/r2. Here, the center point of the sphere lies in the central projection point. N is the number of light beams that fall into the detection region. These light beams penetrate a sphere surface with the radius 1 m and the spatial angle 4πsr. Thus, the beam density in the detection region 40 of ρs=N/4πsr−1 results. In the simplest case, two light beams are sufficient for counting persons. The beam density is then ½sr−1. In order to obtain more data, up to 106 points in the detection region 40 can be used. The beam density is then 106/4πsr−1.

[0089] The light pattern has a code which establishes uniqueness. This is ensured here by a specific arrangement of the light points of the light pattern, in which each point of the light pattern has an environment (submatrix) of light points uniquely assigned to it.

[0090] FIG. 3 shows the detection of persons and/or objects in the detection region 40. The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which are connected to one another by means of interfaces 70. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0091] In the fourth method step for distinguishing, detecting and counting persons and/or objects in facilities and/or vehicles for conveying persons and/or goods, the backscattered radiation from persons and/or objects situated in the detection region 40 is detected in the radiation detector 20. The imaginary line between the optical axis of the radiation source 10 and the optical axis of the radiation detector 20 is referred to as the baseline. If a person enters the detection region 40 over time, the radiation detector 20 observes a shift of parts of the light pattern 50 along the baseline. The program that is executed on the control and evaluation apparatus 60 compares the detected images from the radiation detector 20 with the projected light patterns 50. For small image regions which have experienced a shift in relation to the known light pattern 50, the program calculates the length of the shift, known as the disparity. Since the light pattern 50 on small image regions along the baseline is unique, exactly one disparity is found for each image region. A depth value can be calculated for a small image region from the disparity on the basis of the geometric relationships. In the result, a 3D point cloud is now provided for further evaluation. Optionally, a coded light pattern (see FIG. 2) can also be used.

[0092] FIG. 4 shows the 3D point cloud when the persons and/or objects in the detection region 40 are moving. The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which are connected to one another by means of interfaces 70. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0093] Information about the scene in the detection region 40, including persons and objects present, is represented by the depth values of the 3D point cloud (FIG. 4a). Persons or objects have a characteristic, three-dimensional shape in space. A suitable program, for example a recognition algorithm, searches for parts of such more characteristic shapes in the data of the 3D point cloud. If there is a match, a shape is detected. The position of a specific person or of a specific object can be abstracted by means of a characteristic point, which is determined, for example, by means of the center of gravity method.

[0094] Over time, a series of such characteristic points, which form a trajectory with a known directional progression (FIG. 4b), are created by evaluating many data from the radiation detector 20. If the trajectory intersects a predefined area in the space, the counting area 80, a counting event is generated. From the direction of the trajectory it can be determined whether the person is getting into the vehicle or getting out of the vehicle. The same principle can be applied for objects, for example for bicycles or suitcases, that are brought into the detection region 40 and cross the counting area 80. Optionally, a coded light pattern (see FIG. 2) can also be used.

[0095] FIG. 5 illustrates the determination of the suitable density of the pattern points of the light pattern 50 generated by the radiation source 10. The number of pattern points shown in this figure show only a tendency, not an absolute number, The point density of the fight pattern 50 is to be chosen such that the projected light pattern 50 in small image sections along the direction of shift of the persons and/or objects is unique at any possible position. In addition, the recognition algorithm must recognize characteristic shapes of persons and/or objects reliably. At the same time, in contrast, the generated data volume in the control and evaluation apparatus 60 should be as low as possible. Under these mentioned conditions, the selected point density of the light pattern 50, shown in FIG. 5a, is too low. Although the generated data volume is low, a clear categorization of the person is not possible, nor a reliable recognition of the person. In contrast, the selected point density of the light pattern 50, shown in FIG. 5f, is too high. On the one hand, the individual points of the light pattern can no longer be distinguished by the detector, and on the other hand, the amounts of data to be processed are so large that a considerably more powerful control apparatus and memories with larger capacities would be required and would thus lead to considerably higher costs.

[0096] It has been shown that, for typical operation in vehicles for conveying persons and/or goods, the most favorable point density of the light pattern 50 is one that corresponds to a beam density ρs of at least 1*103/4πsr−1 and maximally 5*100/4*πsr−1, depending on the distance of the device for detecting, categorizing and counting persons and/or objects 1 from the persons and objects to be detected or the detection region 40. Illustrations of these point densities of the light pattern 50 are shown in FIG. 5b-e. For the sake of simplicity, only regular light patterns are shown in FIG. 5. Optionally, however, a coded light pattern (see FIG. 2) can also be used.

[0097] FIG. 6 shows the detection region 40 for detecting, categorizing and counting persons and/or objects of the device for detecting, categorizing and counting persons and/or objects 1 on a door portal 150 of a facility for public passenger transportation. The device for detecting, categorizing and counting persons and/or objects 1 is situated in the upper region at a distance to the door portal 150.

[0098] The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which are connected to one another by means of interfaces 70. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0099] An important feature of the invention is the monitoring of a spatial region. The light of the light pattern projector 100 falls from a central projection point into this spatial region. The radiation detector 20 is oriented such that its spatial field of vision is largely identical to the illuminated spatial region. The common spatial region is the detection region 40 of the device for detecting, categorizing and counting persons and/or objects 1.

[0100] The detection region 40 is described by the spatial angle of the central projection, Depending on the choice of the aperture, the detection region 40 is described by suitable geometric figures, the geometric origins of which lie in the central projection point of the device for detecting, categorizing and counting persons and/or objects 1, With a rectangular aperture, it is the pyramid with a rectangular and even outline; with a round aperture, it is the straight circular cone. The spatial angle of the straight circular cone is: Ω=4πsin2(φ/4), wherein φ is the full beam angle. The spatial angle of the pyramid is: Ω=4 arcsin(sin(φx/2) sin(φy/2)), wherein φx and φy are the two full beam angles. For the use of the invention with the requirement of direction recognition, two light beams are sufficient. The two beams are slightly divergent from one another but detect predominantly the same spatial region. With this geometry, a spatial angle of at least Ω=0.006 sr can be detected. By using additional beams, the detection region 40 can be extended up to the hemisphere. The spatial half below the plane of installation of the device for detecting, categorizing and counting persons and/or objects 1 is then completely monitored; the spatial angle is 2πsr. To carry out the invention, it is sufficient to choose the detection region 40 such that at least one part of the human body of a person and/or one part of an object is detected in the defined spatial region.

[0101] The orientation and location of the counting areas 80, 81 or of the counting volume 90 is shown in FIG. 7. The device for detecting, categorizing and counting persons and/or objects 1 is situated in the upper region at a distance to the door portal 150. The device for detecting, categorizing and counting persons and/or objects 1 has a radiation source 10, an element for deflecting the radiation 30, and a radiation detector 20. In addition, an electronic control and evaluation apparatus 60 is installed in or within communication range of the device for detecting, categorizing and counting persons and/or objects 1, which is connected to one another by means of interfaces 70. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0102] A counting area 80 is a defined area in the detection region 40 (FIG. 7a). If, for example, the passage through a door portal 150 is to be monitored, the counting area 80 can be defined as a plane parallel to the portal opening. The counting plane 80 then typically lies 10 cm in front of and 10 cm behind the opening of the door portal 150. In the context of the invention, distances of 250 cm in front of to 250 cm behind the opening of the door portal are possible. In the general case of curved door portal areas and curved counting areas 80, 81, the distance refers to the shortest distance between the areas. In the context of the invention, at least one counting area 80 which intersects the detection region 40 is defined. Moving persons and/or objects must at least partially pass through the counting area 80 in order to trigger a counting event.

[0103] In order to increase the reliability of the counting, two (FIG. 7b) or more counting areas 80, 81 can also be used. Typically, two counting areas 80, 81 arranged parallel to one another are used. The person or the object must then move at least partially through one counting area 80, 81 of the counting volume (FIG. 7c) defined by the two counting areas 80, 81 and also at least partially penetrate the second surface again with a time delay. A counting event is only triggered once the resulting passage is detected.

[0104] FIG. 8 shows the structure of an exemplary embodiment of the device for detecting, categorizing and counting persons and/or objects 1. The light pattern projector 100 contains the radiation source 10 and optical elements 30 in order to generate the desired light pattern 50 to be projected. One possible embodiment uses a laser diode as the radiation source 10, a collimator lens and a diffractive optical element (DOE) 30. The radiation source 10 generates continuous monochromatic laser radiation S with a wavelength in the range from 780 nm to 1000 nm.

[0105] Along with the objective 110 and the bandpass filter 120, the image sensor 130 forms the radiation detector 20. The bandpass filter 120 is only permeable to light in a narrow spectral window. The central wavelength of the bandpass filter 120 corresponds to the wavelength of the light emitted by the radiation source 10. This prevents light of other wavelengths from exposing the image sensor 130. The image data are processed by the control and evaluation apparatus 80 and evaluated by means of a suitable program. The device for detecting, categorizing and counting persons and/or objects 1 is connected for this purpose via an interface 70 to the control and evaluation apparatus 60. The carrier structure 140 brings the radiation detector 20 and the light pattern projector 100 into a defined position and thus realizes what is known as the baseline.

[0106] By using the light pattern projector 100, the device for detecting, categorizing and counting persons and/or objects 1 actively provides light and can also work in dark environments. Since the illumination is not over a large area, but rather only light is guided in pattern regions, a smaller light power is necessary than with large-area illumination. Accordingly, less energy is consumed and less waste heat is created.

LIST OF REFERENCE SIGNS

[0107] 1 Device for detecting, categorizing and counting persons and/or objects [0108] 10 Radiation source [0109] 20 Radiation detector [0110] 30 Element for deflecting the radiation [0111] 40 Detection region [0112] 50 Light pattern [0113] 60 Control and evaluation apparatus [0114] 70 Counting region [0115] 80, 81 Counting area [0116] 90 Counting volume [0117] 100 Light pattern projector [0118] 110 Objective [0119] 120 Bandpass filter [0120] 130 Image sensor [0121] 140 Carrier structure [0122] 150 Door portal [0123] 160 Facility or vehicle for conveying persons and/or goods [0124] 170 Person [0125] 171 Object [0126] 190 Point of the 3D point cloud [0127] 200 Characteristic point [0128] S Emitted radiation