WO2025134353A1 - Position detection device - Google Patents

Abstract

A position detection device (1) is provided with: a first light-emitting device (110); a second light-emitting device (120); a first light-receiving device (210) that receives light emitted from the first light-emitting device (110); a second light-receiving device (220) that receives light emitted from the second light-emitting device (120); and a position detection unit (11) that detects the position of an object in a detection area (100) using the position of a pixel at which a change in brightness is detected in the first light-receiving device (210) and the position of a pixel at which a change in brightness is detected in the second light-receiving device (220).

Description

Position Detection Device

The present invention relates to a position detection device that detects the position of an object in a detection area.

Detection devices are known that detect objects that have entered a restricted area. For example, some detection devices use a beam switch, and known beams include those that use infrared rays and ultrasonic waves. There are also known detection devices that detect intruding objects by photographing the restricted area and processing the photographed images.

Such detection devices can detect when an object has entered a restricted area, but cannot recognize where within the restricted area the object is located.

For example, Patent Document 1 describes a monitoring device with a position detection unit that includes multiple pairs of transmitters and receivers arranged to face each other in a substantially horizontal direction, and a single transmitter and multiple receivers arranged to face each other diagonally with respect to the horizontal direction. In Patent Document 1, the position of an intruder in a security area is detected using light emitted horizontally and light emitted diagonally.

Patent document 2 describes a monitoring device with a position detection unit in which a transmitter and a receiver are arranged facing each other so that the transmission paths are approximately horizontal in a side view and diagonal to each other in a plan view. In patent document 2, the position where an intruder passes is detected based on the interruption of the diagonal transmission path.

Japanese Patent Publication No. 2016-53872 Japanese Patent Publication No. 2012-58880

However, in the first place, intrusion detection devices using conventional beam switches are unable to determine the position of a detected object. Also, in the monitoring devices described in Patent Documents 1 and 2, it is necessary to precisely align the optical axes of multiple projectors with different light projection directions (transmitters in Patent Document 1, transmitters in Patent Document 2) and the corresponding receivers (receivers in Patent Document 1, receivers in Patent Document 2) for each projector. The task of aligning the optical axes of multiple projectors and corresponding receivers is quite time-consuming and not easy to install.

The present invention was made in consideration of the problems described above, and its purpose is to realize a position detection device that is easy to install.

In order to solve the above problem, a position detection device according to one embodiment of the present invention is a position detection device that detects the position of an object in an area, and includes a first light emitter including a plurality of light-emitting elements arranged in a line that emit an identifiable first specific light into the area, a second light emitter including a plurality of light-emitting elements arranged in a line that emit an identifiable second specific light into the area, a first light receiver that receives the first specific light emitted by the first light emitter, and a second light receiver that receives the second specific light emitted by the second light emitter, and the first light receiver is disposed in front of the plurality of light-emitting elements included in the second light emitter. The first light emitter is disposed at both ends of the straight line, and the second light receiver is disposed at both ends of the straight line of the plurality of light emitting elements included in the first light emitter, and the first light receiver and the second light receiver include an event-based sensor, and the event-based sensor outputs an event signal including the detection time at which a luminance change is detected and the pixel position at which the luminance change is detected for each pixel each time the luminance change is detected, and further includes a position detection unit that detects the position of an object in the area using the pixel position at which the luminance change is detected in the first light receiver and the pixel position at which the luminance change is detected in the second light receiver.

According to one aspect of the present invention, it is possible to realize a position detection device that can detect the position of an object in an area without the need to align the optical axis between the first light emitter and the first light receiver, and the optical axis between the second light emitter and the second light receiver.

1 is a functional block diagram showing a configuration of a main part of a position detection device according to an embodiment of the present invention; 3A to 3C are diagrams for explaining an example of position detection by the position detection device. 3A to 3C are diagrams illustrating the principle of position detection by the position detection device. 3A to 3C are diagrams illustrating the principle of position detection by the position detection device. 3A to 3C are diagrams illustrating the principle of position detection by the position detection device. 3A to 3C are diagrams illustrating the principle of position detection by the position detection device. 10A and 10B are diagrams for explaining examples of modulation patterns of light-emitting elements.

[Detection device overview]
An embodiment of the present invention will be described in detail below. A position detection device 1 according to this embodiment detects the position of an object in a detection area 100. The object in the detection area 100 includes an object that has entered the detection area 100, an object that moves within the detection area 100, and the like.

The position detection device 1 is a position detection device that uses a so-called beam switch. The position detection device 1 uses an event-based sensor as the sensor for receiving light, eliminating the need for optical axis alignment between the light emitter and the light receiver, which was previously required. This makes it possible to realize a position detection device that is easy to install.

[Details of the position detection device]
Fig. 1 is a functional block diagram showing a configuration of a main part of a position detection device 1. As shown in Fig. 1, the position detection device 1 includes a control unit 10, a first light emitter 110, a second light emitter 120, a first light receiver 210, and a second light receiver 220. The control unit 10 includes a position detection unit 11 and a light emitting element setting unit 12.

The position detection unit 11 detects the position of an object in the detection area 100. Details of the position detection method used by the position detection unit 11 will be described later.

The light-emitting element setting unit 12 sets the modulation pattern of the light emitted from the light-emitting element 111 of the first light-emitting device 110 and the light-emitting element 121 of the second light-emitting device 120. The modulation pattern includes changes in amplitude (intensity), wavelength, phase, and emission pattern (on and off timing).

The light-emitting element setting unit 12 sets the modulation pattern of the light emitted from the light-emitting element 111 and the light-emitting element 121, so that the position detection unit 11 can recognize whether the light received by the first light receiver 210 and the second light receiver 220 is emitted from the first light emitter 110 and the second light emitter 120.

The light-emitting element setting unit 12 may be included in the first light receiver 210 or the second light receiver 220. When the first light receiver 210 or the second light receiver 220 includes the light-emitting element setting unit 12, the first light receiver 210 or the second light receiver 220 may transmit the modulation pattern set in the light-emitting element setting unit 12 directly to the first light emitter 110 or the second light emitter 120. This transmission may be wireless or wired.

The light-emitting element setting unit 12 may also change the preset modulation pattern. This change may be made when light having a modulation pattern identical or similar to the preset modulation pattern is received from a source other than the first light-emitting device 110 or the second light-emitting device 120. This makes it possible to prevent the light from being mistakenly determined to be emitted from the first light-emitting device 110 or the second light-emitting device 120 when it is not actually emitted from the first light-emitting device 110 or the second light-emitting device 120. This improves the reliability of position detection by the position detection device 1.

The first light emitter 110 includes a plurality of light emitting elements 111. The second light emitter 120 includes a plurality of light emitting elements 121. The light emitting elements 111 and 121 emit modulated light, which is light modulated according to a modulation pattern set in the light emitting element setting unit 12. The modulated light is light emitted from the light emitting element 111 or the light emitting element 121, and can therefore be called specific light that can be identified. The light emitted from the light emitting element 111 can be called the first specific light, and the light emitted from the light emitting element 121 can be called the second specific light.

The first light receiver 210 is an imaging device that images an area including the first light emitter 110 and the detection area 100 (see FIG. 2), and includes a light receiving sensor 211. The second light receiver 220 is a device that images an area including the first light receiver 210 and the detection area 100, and includes a light receiving sensor 221. The light receiving sensor 211 and the light receiving sensor 221 are event-based sensors. An event-based sensor detects a change in luminance of each pixel in the imaging device as an event, and outputs an event signal including the detection time when the event was detected, the pixel position where the event occurred, and the change in pixel value each time the event is detected.

Therefore, it can be said that the light receiving sensor 211 and the light receiving sensor 221 output an event signal including the detection time when a luminance change was detected for each pixel and the pixel position where the luminance change was detected, every time a luminance change is detected.

By using event-based sensors as the light receiving sensors 211 and 221, the light emitted from the first light emitter 110 can be received by the first light receiver 210 without aligning the optical axes of the first light emitter 110 and the first light receiver 210, as long as the first light emitter 110 is included in the imaging range of the first light receiver 210. If the first light receiver 210 can receive the light, it becomes possible for the first light receiver 210 to detect a change in luminance of the light emitted from the first light emitter 110. Therefore, there is no need to align the optical axes of the first light emitter 110 and the first light receiver 210.

Similarly, even if the optical axes of the second light emitter 120 and the second light receiver 220 are not aligned, as long as the second light emitter 120 is included in the imaging range of the second light receiver 220, the light emitted from the second light emitter 120 can be received by the second light receiver 220. If the second light receiver 220 can receive the light, it becomes possible for the second light receiver 220 to detect a change in luminance of the light emitted from the second light emitter 120. Therefore, there is no need to align the optical axes of the second light emitter 120 and the second light receiver 220.

[Details of position detection process]
2 to 6, an example of detecting the position of an object in the detection area 100 using the position detection device 1 will be described. FIG. 2 is a diagram for explaining an example of detection by the position detection device 1.

In the example shown in FIG. 2, the first light emitter 110 and the first light receiver 210 are disposed opposite each other.
In addition, the second light emitter 120 and the second light receiver 220 are arranged facing each other. Here, facing each other means that the first light receiver 210 is arranged in the direction in which the first light emitter 110 emits light, and the second light receiver 220 is arranged in the direction in which the second light emitter 120 emits light.

The first light emitter 110 includes five light emitting elements 111, from light emitting element 111A to light emitting element 111E. Light emitting elements 111A to 111E are arranged in a straight line, and all emit light in the same direction.

The second light emitter 120 includes five light emitting elements 121, from light emitting element 121A to light emitting element 121E. Light emitting elements 121A to 121E are arranged in a straight line, and all emit light in the same direction.

The first light receiver 210 is arranged at both ends of a straight line of a plurality of light emitting elements 121 included in the second light emitter 120. Here, the first light receiver 210 arranged at one end of the straight line in which the light emitting elements 121 are arranged is referred to as the first light receiver 210A, and the first light receiver 210 arranged at the other end is referred to as the first light receiver 210B.

The second light receiver 220 is arranged at both ends of the straight line of the multiple light emitting elements 111 included in the first light emitter 110. Here, the second light receiver 220 arranged at one end of the straight line in which the light emitting elements 111 are arranged is referred to as the second light receiver 220A, and the second light receiver 220 arranged at the other end is referred to as the second light receiver 220B.

The first light receiver 210A is disposed at an oblique position relative to the second light receiver 220B, and the first light receiver 210B is disposed at an oblique position relative to the second light receiver 220A.

The multiple light-emitting elements 111 included in the first light-emitting device 110 may be arranged in a straight line in the vertical direction. The multiple light-emitting elements 121 included in the second light-emitting device 120 may also be arranged in a straight line in the vertical direction. The first light-emitting device 110 and the second light-emitting device 120 may be arranged at the same height. As a result, the pixel position where a luminance change is detected indicates the height in the detection area 100, making it possible to detect the height of an object in the detection area 100. It is also possible to recognize whether the object whose position has been detected is floating in the air.

Furthermore, the height including the first light emitter 110 and the second light receivers 220 arranged at both ends of the first light emitter 110 may be the same as the height including the second light emitter 120 and the first light receivers 210 arranged at both ends of the second light emitter 120.

The range through which light emitted from each of the five light-emitting elements 121 received by the first light receiver 210A passes becomes the detection area 100A. The range through which light emitted from each of the five light-emitting elements 121 received by the first light receiver 210B passes becomes the detection area 100B. The range through which light emitted from each of the five light-emitting elements 111 received by the second light receiver 220A passes becomes the detection area 100C. The range through which light emitted from each of the five light-emitting elements 111 received by the second light receiver 220B passes becomes the detection area 100D.

The combined area of detection area 100A, detection area 100B, detection area 100C, and detection area 100D becomes detection area 100 in which the position detection device 1 can detect the position of an object.

When an object is present in the detection area 100, the object blocks the light emitted from the light-emitting element 111 and the light-emitting element 121. As a result, the light-receiving sensor 211 of the first light-receiver 210 and the light-receiving sensor 221 of the second light-receiver 220 detect a change in luminance in the pixel corresponding to the position of the object. Then, an event signal is output.

When the position detection unit 11 receives an event signal from the light receiving sensor 211 and the light receiving sensor 221, it detects the position of an object in the detection area 100 using the change in luminance indicated by the event signal, the position of the pixel, and the modulation pattern of the light received by that pixel.

More specifically, the position detection unit 11 recognizes from the light modulation pattern and pixel positions that the received light is emitted from a specific light-emitting element 111 of the first light-emitting device 110 and a specific light-emitting element 121 of the second light-emitting device 120. When the light emitted from the light-emitting element 111 or the light-emitting element 121 is blocked by an object or the like and changes in luminance, the position detection unit 11 detects the position of the object in the detection area 100 using the light-emitting element 111 or the light-emitting element 121 that has caused the luminance change and the light-emitting element 111 or the light-emitting element 121 that has not caused the luminance change.

The luminance change occurring in the light receiving sensors 211 and 221 that the position detection unit 11 uses to detect the position of an object is not a luminance change based on the modulation of the modulated light, but a luminance change that occurs when the modulated light is blocked by an object. Even if a luminance change based on the modulation of the modulated light occurs in the light receiving sensors 211 and 221, the position detection unit 11 will not detect the position of an object in the detection area 100.

The principle by which the position detection unit 11 can detect the position of an object in the detection area 100 is as follows.

(Detection Example 1)
For example, when an intruder X1 is located at a position as shown in FIG. 3, of the light emitted from the light-emitting element 111 and received by the first light receiver 210A, the light emitted from the light-emitting element 111A, the light-emitting element 111B, the light-emitting element 111C, and the light-emitting element 111D are received by the first light receiver 210A, but the light emitted from the light-emitting element 111E is blocked by the intruder X1 and is not received by the first light receiver 210A.

Furthermore, of the light emitted from light-emitting element 111 and received by first light receiver 210B, the light emitted from light-emitting element 111A and light-emitting element 111B is received by first light receiver 210A, but the light emitted from light-emitting element 111C, light-emitting element 111D, and light-emitting element 111E is blocked by intruder X1 and is not received by first light receiver 210B.

If the boundary between the light received by the first light receiver 210A and the light that cannot be received is defined as boundary line 301A, and the boundary between the light received by the first light receiver 210B and the light that cannot be received is defined as boundary line 301B, the point where boundary lines 301A and 301B intersect indicates the position of intruder X1.

If the positional relationship between the first light emitter 110 and the first light receiver 210 can be recognized in advance, it is possible to derive the position of the intersection between the border line 301A and the border line 301B in the detection area 100. The position detection unit 11 then detects the position of the intruder X1 in the detection area 100 from the intersection between the border line 301A and the border line 301B.

(Detection Example 2)
When an intruder X2 is present in a position as shown in FIG. 4, of the light emitted from the light-emitting element 121 and received by the second light receiver 220A, the light emitted from the light-emitting element 1211A, the light-emitting element 121B, the light-emitting element 121C, and the light-emitting element 121D are received by the first light receiver 210A, but the light emitted from the light-emitting element 121E is blocked by the intruder X2 and is not received by the second light receiver 220A.

Furthermore, of the light emitted from the light-emitting element 121 and received by the second light receiver 220B, the light emitted from the light-emitting element 121A and the light-emitting element 121B is received by the second light receiver 220A, but the light emitted from the light-emitting element 121C, the light-emitting element 121D, and the light-emitting element 121E is blocked by the intruder X2 and is not received by the second light receiver 220B.

If the boundary between the light received by the second light receiver 220A and the light that cannot be received is defined as boundary line 302A, and the boundary between the light received by the second light receiver 220B and the light that cannot be received is defined as boundary line 302B, the point where boundary lines 302A and 302B intersect indicates the position of intruder X2.

If the positional relationship between the second light emitter 120 and the second light receiver 220 can be recognized in advance, it is possible to derive the position of the intersection between the boundary line 302A and the boundary line 302B in the detection area 100. The position detection unit 11 then detects the position of the intruder X2 in the detection area 100 from the intersection between the boundary line 302A and the boundary line 302B.

(Detection Example 3)
When an intruder X3 is located at a position as shown in FIG. 5, of the light emitted from the light-emitting element 111 and received by the first light receiver 210A, the light emitted from the light-emitting element 1111A and the light-emitting element 111B is received by the first light receiver 210A, but the light emitted from the light-emitting element 111C, the light-emitting element 111D, and the light-emitting element 111E is blocked by the intruder X3 and is not received by the first light receiver 210A.

Furthermore, of the light emitted from the light-emitting element 121 and received by the second light receiver 220A, the light emitted from the light-emitting element 121A and the light-emitting element 121B is received by the second light receiver 220A, but the light emitted from the light-emitting element 121C, the light-emitting element 121D, and the light-emitting element 121E is blocked by the intruder X3 and is not received by the second light receiver 220A.

If the boundary between the light received by the first light receiver 210A and the light that cannot be received is defined as boundary line 303A, and the boundary between the light received by the second light receiver 220A and the light that cannot be received is defined as boundary line 303B, the point where boundary line 303A and boundary line 303B intersect indicates the position of intruder X3.

If the positional relationship between the first light emitter 110 and the first light receiver 210, and the positional relationship between the second light emitter 120 and the second light receiver 220 can be recognized in advance, it is possible to derive the position of the intersection between the boundary line 303A and the boundary line 303B in the detection area 100. The position detection unit 11 then detects the position of the intruder X3 in the detection area 100 from the intersection between the boundary line 303A and the boundary line 303B.

(Detection Example 4)
When an intruder X4 is located at a position as shown in FIG. 6, of the light emitted from the light-emitting element 111 and received by the first light receiver 210B, the light emitted from the light-emitting element 1111C, the light-emitting element 111D, and the light-emitting element 111E are received by the first light receiver 210A, but the light emitted from the light-emitting element 111A and the light-emitting element 111B are blocked by the intruder X4 and are not received by the first light receiver 210B.

Furthermore, of the light emitted from the light-emitting element 121 and received by the second light receiver 220B, the light emitted from the light-emitting element 121C, the light-emitting element 121D, and the light-emitting element 121E is received by the second light receiver 220B, but the light emitted from the light-emitting element 121A and the light-emitting element 121B is blocked by the intruder X4 and is not received by the second light receiver 220B.

If the boundary between the light received by the first light receiver 210B and the light that cannot be received is defined as boundary line 304A, and the boundary between the light received by the second light receiver 220B and the light that cannot be received is defined as boundary line 304B, the point where boundary lines 304A and 304B intersect indicates the position of intruder X4.

and,
If the positional relationship between the first light emitter 110 and the first light receiver 210, and the positional relationship between the second light emitter 120 and the second light receiver 220 can be recognized in advance, it is possible to derive the position of the intersection between the boundary line 304A and the boundary line 304B in the detection area 100. Therefore, the position detection unit 11 detects the position of the intruder X4 in the detection area 100 from the intersection between the boundary line 304A and the boundary line 304B.

As described above, by using the first light receiver 210A, the first light receiver 210B, the second light receiver 220A, and the second light receiver 220B, the position of the intruder X in the detection area 100 can be detected regardless of where the intruder X is located in the detection area 100.

In the above detection examples 1 to 4, examples have been described in which the position is detected using two of the four light receivers (first light receiver 210A, first light receiver 210B, second light receiver 220A, second light receiver 220B), but this is not limited thereto, and the position of an object may be detected using all four light receivers. Even when four light receivers are used, the position of the intruder X in the detection area 100 can be detected by deriving the position of the intersection of the boundary between the light emitted from the light emitting element 111 or the light emitting element 121 that was received by the first light receiver 210 or the second light receiver 220 and the light that was not received.

Note that with regard to a change in luminance, the position detection unit 11 may determine that the light of the light-emitting element 111 or light-emitting element 121 corresponding to the pixel in question has been blocked when there is a change in luminance, or may compare the amount of change in luminance with a threshold, and determine that the light of the light-emitting element 111 or light-emitting element 121 corresponding to the pixel in question has been blocked when the amount of change in luminance is equal to or greater than the threshold. Also, only when the luminance becomes smaller, i.e., becomes darker, may the position detection unit 11 determine that the light of the light-emitting element 111 or light-emitting element 121 corresponding to the pixel in question has been blocked.

In addition, even if natural light different from the light emitted from the first light emitter 110 or the second light emitter 120 is blocked by trees or the like and a change in brightness is detected by the first light receiver 210 or the second light receiver 220, the position detection device 1 does not perform position detection processing in the detection area 100.

As described above, the position detection device 1 according to this embodiment detects the position of an object within the detection area 100 .
The position detection device 1 includes, in the detection area 100 , a first light emitter 110 , a second light emitter 120 , a first light receiver 210 , a second light receiver 220 , and a position detection unit 11 .

The first light emitter 110 includes a plurality of light emitting elements 111 arranged in a straight line that emit a first identifiable specific light. The second light emitter 120 includes a plurality of light emitting elements 121 arranged in a straight line that emit a second identifiable specific light in the detection area 100.

The first light receiver 210 is disposed at both ends of the straight line of the multiple light emitting elements 121 included in the second light emitter 120, and receives the first specific light emitted by the first light emitter 110. The second light receiver 220 is disposed at both ends of the straight line of the multiple light emitting elements 111 included in the first light emitter 110, and receives the second specific light emitted by the second light emitter 120.

The first light receiver 210 includes a light receiving sensor 211, which is an event-based sensor. The second light receiver 220 includes a light receiving sensor 221, which is an event-based sensor. The light receiving sensors 211 and 221 output an event signal each time a luminance change is detected, the event signal including the detection time at which a luminance change was detected and the pixel position at which the luminance change was detected, for each pixel.

The position detection unit 11 detects the position of an object in the detection area 100 using the pixel position at which a luminance change is detected in the first light receiver 210 and the pixel position at which a luminance change is detected in the second light receiver 220.

When an object enters the detection area 100, a portion of the light emitted from the first light emitter 110 and the second light emitter 120 is blocked. As a result, in each of the first light receiver 210 and the second light receiver 220, a change in luminance is detected in the pixel corresponding to the position of the blocked light. Then, from the pixel position where the change in luminance is detected, it is possible to recognize which light-emitting element has blocked the light emitted from.

The boundary where light is blocked by an object can be recognized from the pixel positions where a luminance change is detected by the first light receiver 210 and the pixel positions where a luminance change is not detected. If the line indicating the boundary of the light emitted from the first light emitter 110 and received by the first light receiver 210 is called the first line, and the line indicating the boundary of the light emitted from the second light emitter 120 and received by the second light receiver 220 is called the second line, the intersection of the first line and the second line indicates the position of the object in the detection area 100. Therefore, the position of the object in the detection area 100 can be detected from the position of the intersection of the first line and the second line.

The first light receiver 210 and the second light receiver 220 simply receive the light emitted from the first light emitter 110 and the second light emitter 120, so work such as aligning the optical axis is not required. Therefore, it is possible to realize a position detection device 1 that detects the position of an object in the detection area 100 without the need for the time-consuming work of aligning the optical axis.

Furthermore, the first light emitter 110 and the first light receiver 210, and the second light emitter 120 and the second light receiver 220 may be spaced apart by a predetermined distance or more, for example, 500 m or more. In the conventional configuration, it was necessary to align the optical axes of the light emitter and the light receiver, making it difficult to arrange them at a long distance, for example, 500 m or more.

As described above, in the position detection device 1, there is no need to align the optical axes of the first light emitter 110 and the first light receiver 210, and the second light emitter 120 and the second light receiver 220. As long as the light emitted from the first light emitter 110 or the second light emitter 120 can be received by the first light receiver 210 or the second light receiver 220, the position of an object within the detection area 100 can be accurately detected even if the first light emitter 110 and the first light receiver 210, and the second light emitter 120 and the second light receiver 220 are separated by 500 m or more.

[Example of modulation pattern of light-emitting element]
Next, an example of the modulation pattern of the light-emitting element 111 will be described with reference to Fig. 7. Note that the modulation pattern of the light-emitting element 111 can be similarly applied to the light-emitting element 121. Fig. 7 is a diagram for explaining an example of the modulation pattern of the light-emitting element 111. Fig. 7 shows an example in which the first light emitter 110 includes 15 light-emitting elements 111. Here, these are light-emitting elements 111X1 to 111X5, light-emitting elements 111Y1 to 111Y5, and light-emitting elements 111Z1 to 111Z5, respectively.

As an example, the light emitting elements 111 are divided into multiple groups, and each group emits light with a different modulation pattern. For example, 15 light emitting elements 111 are divided into three groups, light emitting elements 111X, light emitting elements 111Y, and light emitting elements 111Z, and light emitting elements 11X, light emitting elements 111Y, and light emitting elements 111Z emit light with different modulation patterns. Note that light emitting elements 111X include light emitting elements 111X1 to 111X5. Light emitting elements 111Y include light emitting elements 111Y1 to 111Y5. Light emitting elements 111Z include light emitting elements 111Z1 to 111Z5.

If light-emitting element 111X emits light of modulation pattern A, light-emitting element 111Y emits light of modulation pattern B, and light-emitting element 111Z emits light of modulation pattern C, then when the first light receiver 210 receives light of modulation pattern A, it can recognize that the light is emitted from light-emitting element 111X. Furthermore, when it receives light of modulation pattern B, it can recognize that the light is emitted from light-emitting element 111Y. Furthermore, when it receives light of modulation pattern C, it can recognize that the light is emitted from light-emitting element 111Z.

As another example, light emitting elements 111X1, 111Y1, and 111Z1 may be grouped together, light emitting elements 111X2, 111Y2, and 111Z2 may be grouped together, light emitting elements 111X3, 111Y3, and 111Z3 may be grouped together, light emitting elements 111X4, 111Y4, and 111Z4 may be grouped together, and light emitting elements 111X5, 111Y5, and 111Z5 may be grouped together, with each group emitting light with a different modulation pattern.

If the resolution of the light receiving sensor 211 of the first light receiver 210 is not sufficient to distinguish all of the light emitting elements 111 of the first light emitter 110 due to the distance between the first light emitter 110 and the first light receiver 210, the first light receiver 210 will not be able to grasp the exact position of each of the light emitting elements 111.

Even in such a case, if light with a different modulation pattern is emitted for each group, it is possible to distinguish between the modulation patterns, and therefore the light-emitting elements 111 can be distinguished between groups. Therefore, even if the resolution of the light receiving sensor 211 is not sufficient to distinguish between all of the light-emitting elements 111, it is possible for the first light receiver 210 to distinguish between the light-emitting elements 111.

Furthermore, the light may be emitted at different light emission timings for each group. As with the case where the modulation patterns are different, when the light emission timings are different for each group, even if the resolution of the light receiving sensor 211 is not sufficient to distinguish all of the light emitting elements 111, it is possible for the first light receiver 210 to distinguish between the light emitting elements 111.

[Software implementation example]
The functions of the position detection device 1 (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and a program for causing a computer to function as each control block of the device (particularly each part included in the control unit 10).

In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The functions described in each of the above embodiments are realized by executing the program using this control device and storage device.

The above program may be recorded on one or more computer-readable recording media, not on a temporary basis. The recording media may or may not be included in the device. In the latter case, the above program may be supplied to the device via any wired or wireless transmission medium.

Furthermore, some or all of the functions of each of the above control blocks can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as each of the above control blocks is formed is also included in the scope of the present invention. In addition, it is also possible to realize the functions of each of the above control blocks by, for example, a quantum computer.

Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI may run on the control device, or may run on another device (such as an edge computer or a cloud server).

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments.

〔summary〕
A position detection device according to a first aspect of the present invention is a position detection device that detects the position of an object in an area, the position detection device including a first light emitter including a plurality of light emitting elements arranged in a line that emits an identifiable first specific light in the area, a second light emitter including a plurality of light emitting elements arranged in a line that emits an identifiable second specific light in the area, a first light receiver that receives the first specific light emitted by the first light emitter, and a second light receiver that receives the second specific light emitted by the second light emitter, the first light receiver being arranged at both ends of the line of the plurality of light emitting elements included in the second light emitter. the second light receiver is disposed at both ends of the straight line of the plurality of light-emitting elements included in the first light emitter, the first light receiver and the second light receiver include an event-based sensor, the event-based sensor outputs, for each pixel, an event signal including a detection time at which a luminance change is detected and a pixel position at which the luminance change is detected, and the position detection unit detects a position of an object in the area using the pixel position at which the luminance change is detected in the first light receiver and the pixel position at which the luminance change is detected in the second light receiver.

The light emitted from the first light emitter is received by the first light receiver. The light emitted from the second light emitter is received by the second light receiver. The first light receiver is disposed at both ends of the linear light emitting elements of the second light emitter, and the second light receiver is disposed at both ends of the linear light emitting elements of the first light emitter. Thus, the first light emitter and the second light emitter are disposed opposite each other.

If an object enters the area and blocks the light emitted from the first and second light emitters, it is possible to determine which light-emitting element has blocked the light from the pixel positions where the luminance change is detected in each of the first and second light receivers.

Here, the boundary where light is blocked by an object can be recognized from the pixel positions where a change in luminance is detected in the first light receiver and the pixel positions where no change in luminance is detected.

If the line indicating the boundary of the light emitted from the first light emitter and received by the first light receiver is called the first line, and the line indicating the boundary of the light emitted from the second light emitter and received by the second light receiver is called the second line, the intersection of the first line and the second line indicates the position of the object in the area. Therefore, the position of the object in the area can be detected from the position of the intersection of the first line and the second line.

Therefore, with the above configuration, it is possible to realize a position detection device that can detect the position of an object in an area without the need to align the optical axis between the first light emitter and the first light receiver, and the optical axis between the second light emitter and the second light receiver.

In the position detection device according to aspect 2 of the present invention, in the above aspect 1, the first specific light and the second specific light are modulated light. With the above configuration, it is easy to determine whether the light is emitted from a light-emitting element.

The position detection device according to aspect 3 of the present invention is the same as that according to aspect 1 or 2, in which the light-emitting elements included in the first light-emitting device are arranged in a vertical line, the light-emitting elements included in the second light-emitting device are arranged in a vertical line, and the first light-emitting device and the second light-emitting device are arranged at the same height.

With the above configuration, the pixel position where a change in brightness is detected indicates the height in the area. This makes it possible to detect the height of an object in the area. It can also be recognized whether or not the object is floating in the air.

The position detection device according to aspect 4 of the present invention is any one of aspects 1 to 3, in which the first light emitter and the first light receiver, and the second light emitter and the second light receiver are separated by 500 m or more.

In conventional configurations, it was necessary to align the optical axes of the light emitter and the light receiver, making it difficult to place them a long distance apart, for example, more than 500 m apart. With the above configuration, the light emitted from the first light emitter and the second light receiver is received by the event-based sensors included in the first light receiver and the second light receiver, respectively. This eliminates the need to align the optical axes, and makes it possible to accurately detect the position of objects within the area even when the first light emitter and the first light receiver, and the second light emitter and the second light receiver, are more than 500 m apart.

The position detection device according to aspect 5 of the present invention is any one of aspects 1 to 4, in which the multiple light-emitting elements included in the first light-emitting device are divided into multiple groups, and the first light-emitting device emits light with a modulation pattern of the light-emitting elements that differs for each group, and the multiple light-emitting elements included in the second light-emitting device are divided into multiple groups, and the second light-emitting device emits light with a modulation pattern of the light-emitting elements that differs for each group.

With the above configuration, the modulation pattern of the light-emitting elements is different for each group, so even if the light emitter and the light receiver are far enough apart that the resolution of the event-based sensor cannot distinguish between the light-emitting elements, the light-emitting elements can be distinguished for each group.

The position detection device according to aspect 6 of the present invention is the same as in aspect 5, in which the first light emitter and the second light emitter emit light with different light emission timings for the light emitting elements for each group.

With the above configuration, the light emission timing of the light-emitting elements differs for each group, so even if the light emitter and the light receiver are far enough apart that the resolution of the event-based sensor cannot distinguish between the light-emitting elements, the light-emitting elements can be distinguished for each group.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, new technical features can be formed by combining the technical means disclosed in the respective embodiments.

REFERENCE SIGNS LIST 1 Position detection device 10 Control unit 11 Position detection unit 12 Light-emitting element setting unit 100 Detection area 110 First light emitter 111, 111A to 111E Light-emitting element 120 Second light emitter 121, 121A to 121E Light-emitting element 210, 210A, 210B First light receiver 211 Light-receiving sensor 220, 220A, 220B Second light receiver 221 Light-receiving sensor

Claims (6)

A position detection device for detecting a position of an object in an area, comprising:
A first light emitter including a plurality of light emitting elements arranged in a line and emitting a first specific light that can be specified in the area;
A second light emitter including a plurality of light emitting elements arranged in a line and emitting a second specific light that can be specified in the area;
a first light receiver that receives the first specific light emitted by the first light emitter;
A second light receiver that receives the second specific light emitted by the second light emitter,
The first light receiver is disposed on both ends of the straight line of the plurality of light emitting elements included in the second light emitter,
The second light receiver is disposed at both ends of the straight line of the plurality of light emitting elements included in the first light emitter,
the first light receiver and the second light receiver include an event-based sensor, and the event-based sensor outputs, for each pixel, an event signal including a detection time at which a luminance change is detected and a pixel position at which the luminance change is detected, every time the luminance change is detected;
The position detection device further includes a position detection unit that detects a position of an object in the area using the pixel position where the luminance change is detected in the first optical receiver and the pixel position where the luminance change is detected in the second optical receiver. The position detection device according to claim 1, wherein the first specific light and the second specific light are modulated lights. The plurality of light emitting elements included in the first light emitter are arranged in a vertical straight line,
The plurality of light emitting elements included in the second light emitter are arranged in a vertical straight line,
The position detection device according to claim 1 , wherein the first light emitter and the second light emitter are disposed at the same height. The position detection device according to claim 1, wherein the first light emitter and the first light receiver, and the second light emitter and the second light receiver are separated by 500 m or more. The plurality of light emitting elements included in the first light emitter are divided into a plurality of groups, and the first light emitter emits light by changing a modulation pattern of the light emitting elements for each group;
The position detection device according to claim 2 , wherein the plurality of light emitting elements included in the second light emitter are divided into a plurality of groups, and the second light emitter emits light with a modulation pattern of the light emitting elements that differs for each group. The position detection device according to claim 5, wherein the first light emitter and the second light emitter emit light with different light emission timings for the light emitting elements for each group.

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