Optical wireless communication system and receiving device

Abstract

To provide a technique capable of estimating a camera position without having high processing performance.SOLUTION: An optical wireless communication system includes a plurality of light sources, a receiving device including an event camera, and an information processing device. Each of the plurality of light sources transmits an optical wireless communication signal. The receiving device receives the optical wireless communication signal via the event camera. The optical wireless communication signal includes position-related information for identifying a position in an absolute coordinate system of a transmission source of the optical wireless communication signal. The information processing device identifies a signal region of the optical wireless communication signal in an image plane coordinate system of an image plane obtained by the event camera to acquire a light source image position indicating a position at which each of the plurality of light sources is projected in the image plane coordinate system, acquires a light source absolute position indicating a position at which each of the plurality of light sources is located in the absolute coordinate system on the basis of the position-related information included in the optical wireless communication signal, and uses the light source image position and the light source absolute position to estimate a position and a direction of the event camera in the absolute coordinate system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical wireless communication system and a receiving device used to estimate the absolute position and orientation of a camera. [Background technology]

[0002] A known existing technique is to estimate the position and orientation of a camera using multiple blinking light sources and the camera itself.

[0003] Patent Document 1 discloses an optical marker system that estimates the position and orientation of a camera. The camera captures an image containing blinking light-emitting points (LED markers) and non-blinking feature points. The LED markers are identified based on the blinking patterns detected from the captured image, and the position and orientation of the camera are estimated from the three-dimensional positions of the identified LED markers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-033366 Summary of the Invention [Problem to be solved by the invention]

[0005] The optical marker system disclosed in Patent Document 1 uses a normal camera (frame-based camera) to estimate the camera's position and orientation. The frame-based sensor built into a normal camera outputs information about all pixels as an image at regular time intervals (frame rate), which tends to result in a large amount of data. Therefore, the information processing device must have high processing performance to process the obtained images.

[0006] One object of the present disclosure is to provide a technology that can execute camera position estimation even if the information processing device does not have particularly high processing performance. [Means for solving the problem]

[0007] The first aspect relates to an optical wireless communication system. The optical wireless communication system includes a plurality of light sources, a receiving device having an event camera, and an information processing device. Each of the plurality of light sources transmits an optical wireless communication signal. The receiving device receives the optical wireless communication signal through the event camera. The optical wireless communication signal includes position-related information for identifying the position of the source of the optical wireless communication signal in an absolute coordinate system. The information processing device acquiring light source image positions indicating positions where each of the plurality of light sources is projected onto the image plane coordinate system by identifying a signal region of the optical wireless communication signal in an image plane coordinate system of the image plane obtained by the event camera; acquiring light source absolute positions indicating positions of each of the plurality of light sources in an absolute coordinate system based on position-related information included in the optical wireless communication signal; The position and orientation of the event camera in the absolute coordinate system are estimated using the light source image position and the light source absolute position. It is configured as follows.

[0008] The second aspect relates to a receiving device. The receiving device Event cameras and an information processing device that receives, via an event camera, optical wireless communication signals transmitted from each of a plurality of light sources; Equipped with. The optical wireless communication signal includes position-related information for identifying the position of the source of the optical wireless communication signal in an absolute coordinate system. The information processing device acquiring light source image positions indicating positions where each of the plurality of light sources is projected onto the image plane coordinate system by identifying a signal region of the optical wireless communication signal in an image plane coordinate system of the image plane obtained by the event camera; acquiring light source absolute positions indicating positions of each of the plurality of light sources in an absolute coordinate system based on position-related information included in the optical wireless communication signal; The light source image position and the absolute light source position are used to estimate the position and orientation of the event camera in the absolute coordinate system. [Effects of the Invention]

[0009] The receiving device in the optical wireless communication system is equipped with an event camera. The event camera detects only information about pixels that detect a brightness change above a threshold and outputs it as event data. Therefore, the receiving device can detect optical signals efficiently, and the amount of event data is smaller than the amount of image data output by a normal camera. This means that in the optical wireless communication system, camera position estimation can be performed even if the information processing device does not have particularly high processing performance. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an overview of an optical wireless communication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the geometric relationship between the light source absolute position and the light source image position. [Figure 3] FIG. 10 is a schematic diagram showing the process of acquiring the light source image position. [Figure 4] 1 is a graph showing data frequencies of an optical signal and noise; [Figure 5] 1A and 1B are schematic diagrams showing some examples of light source absolute position acquisition. [Figure 6] 10A and 10B are diagrams illustrating an image plane before and after light source image position acquisition and light source absolute position acquisition are performed. [Figure 7] FIG. [Figure 8] FIG. 1 is a block diagram showing a first configuration example of an optical wireless communication system. [Figure 9] FIG. 10 is a block diagram showing a second configuration example of the optical wireless communication system. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0012] 1.Basic configuration 1 is a diagram illustrating an overview of an optical wireless communication system 1 according to the present embodiment. The optical wireless communication system 1 includes a plurality of light sources 10-1 to 10-n (n is an integer satisfying n≧2), a receiving device 20 equipped with an event camera 21, and an information processing device 30.

[0013] The multiple light sources 10-1 to 10-n are fixedly attached in space and installed indoors or outdoors. Examples of the multiple light sources 10-1 to 10-n include visible light LEDs (light emitting diodes) and infrared LEDs. Visible light LEDs are widely used in street lights, indoor lights, traffic lights, electronic billboards, etc., so using visible light LEDs in the optical wireless communication system 1 leads to effective use of existing facilities. Visible light LEDs repeatedly blink at a speed that is too fast for the human eye to detect, so by controlling the blinking, visible light can be used as a communication signal. It is preferable that the multiple light sources 10-1 to 10-n are simultaneously included within the angle of view of the event camera 21.

[0014] A light source 10-i (i = 1 to n) constituting the plurality of light sources 10-1 to 10-n transmits an optical wireless communication signal Si by blinking. The optical wireless communication signal Si includes position related information Pi for specifying an absolute light source position AP-i indicating the position of the light source 10-i, which is the source of the signal, in an absolute coordinate system. In the drawings of the present disclosure, the absolute coordinate system is represented by the X axis, the Y axis, and the Z axis. The absolute light source position AP-i of the light source 10-i is also expressed by [X i ,Y i ,Z i Hereinafter, for simplicity, the "optical wireless communication signal Si" will be simply referred to as the "optical signal Si."

[0015] The receiving device 20 receives the optical signal Si through the event camera 21. Preferably, the receiving device 20 simultaneously receives the optical signals S-1 to Sn transmitted from each of the multiple light sources 10-1 to 10-n. Typical examples of the receiving device 20 include a smartphone, a tablet, and a wearable device for augmented reality. Furthermore, the receiving device 20 is not limited to these examples, and any object equipped with the event camera 21 can function as the receiving device 20. For example, if a vehicle, a robot, a wheelchair, a cane, or the like is equipped with the event camera 21, it can function as the receiving device 20. In this way, the receiving device 20 is typically an object or terminal that is not fixed in space. When the receiving device 20 moves, the event camera 21 also moves accordingly.

[0016] The event camera 21 has a built-in event-based vision sensor (EV sensor). The EV sensor observes changes in the luminance of light received by the pixels (image sensors) within the EV sensor. When the EV sensor observes a luminance change equal to or greater than a preset threshold, it detects the luminance change as an "event." An event is detected when a situation different from the previous situation occurs. For example, when the subject or the event camera 21 moves, the relative position between the subject and the event camera 21 changes, causing the subject to appear in a pixel where it had not previously existed. At this time, a significant luminance change occurs in the pixels surrounding the subject, which is detected as an event. In addition, the optical signal Si also generates a luminance change due to the blinking of the light source 10-i, and is therefore detected as an event.

[0017] The event camera 21 outputs data related to a pixel where an event is detected as event data EVD. The event data EVD includes at least the coordinates on the image plane of the pixel where the event occurred, the time when the event was detected, and the brightness polarity (positive / negative). The threshold value referenced by the EV sensor when detecting a brightness change is set to be changeable. When an event occurs, threshold values ​​are set on the positive side (a change toward brightness) and the negative side (a change toward darkness) of a voltage (reference voltage) based on the brightness level at that time. A voltage change exceeding the positive threshold is detected as a positive event, and a voltage change exceeding the negative threshold is detected as a negative event. In other words, the EV sensor detects the light signal Si when the light source 10-i turns on as a positive event, and when the light source 10-i turns off as a negative event.

[0018] The information processing device 30 acquires event data EVD from the event camera 21. The information processing device 30 acquires the two-dimensional position of the optical signal Si on the image plane using the event data EVD. This two-dimensional position indicates the position where the light source 10-i is projected on the image plane. Hereinafter, the position where the light source 10-i is projected on the image plane will be referred to as the "light source image position IP-i," and the process of acquiring the light source image position IP-i will be referred to as "light source image position acquisition." In the present disclosure, the image plane coordinate system is represented by the u axis and the v axis. Furthermore, the light source image position IP-i of the light source 10-i is expressed as [u i ,v i The information processing device 30 may be included in the receiving device 20 or may be an external device to the receiving device 20.

[0019] Furthermore, the information processing device 30 acquires the three-dimensional position (light source absolute position AP-i) of the light source 10-i in the absolute coordinate system from the position related information Pi included in the optical signal Si. Hereinafter, the process of acquiring the light source absolute position AP-i will be referred to as "light source absolute position acquisition." Specific examples of the position related information Pi and the light source absolute position acquisition will be described later.

[0020] Through the above-described steps, the information processing device 30 calculates the light source absolute position AP-i ([X i ,Y i ,Z i ]) and the light source image position IP-i ([u i ,v i ]). FIG. 2 is a perspective view showing the geometric relationship between the light source absolute position AP-i and the light source image position IP-i. The information processing device 30 estimates the position and orientation of the event camera 21 in the absolute coordinate system from the geometric relationship between the n sets of data sets. More specifically, a rotation matrix and a translation vector are obtained from the n sets of data sets. A specific solution is known as the PnP (Perspective n Point) problem, and the number of data sets (i.e., the value of n) required to solve this problem varies depending on the method. For example, a method called the 8-point algorithm is known as one method for solving such problems. Note that since the event camera 21 is provided in the receiving device 20, estimating the absolute position and orientation of the event camera 21 is synonymous with estimating the absolute position and orientation of the receiving device 20.

[0021] As described above, the information processing device 30 estimates the absolute position and orientation of the event camera 21 by acquiring the light source image position and the light source absolute position. This series of processes is hereinafter referred to as "camera position estimation." Existing position estimation systems (e.g., satellite positioning systems) may not be able to accurately determine position in places where satellite radio waves are difficult to reach (inside buildings, underground, between high-rise buildings, etc.). On the other hand, camera position estimation using the optical wireless communication system 1 does not use satellite radio waves, so it can be said that there are fewer restrictions on the places where it can be used.

[0022] 2. Camera position estimation A series of processes relating to camera position estimation will be described in detail below.

[0023] 2-1.Light source image position acquisition FIG. 3 is a schematic diagram showing the process of acquiring the light source image position.

[0024] 3A is a graph showing the spatiotemporal distribution of the event data EVD received by the information processing device 30 from the event camera 21. The event data EVD includes not only events caused by the blinking of the light source 10-i (i.e., the optical signal Si) but also noise N, which is an event caused by the movement of the subject or the event camera 21. In other words, the event data EVD is output in a state where the optical signal Si necessary for camera position estimation and the noise N unnecessary for camera position estimation are mixed together. Therefore, in order for the information processing device 30 to acquire the light source image position IP-i, it is necessary to perform signal separation, which is a process of separating the optical signal Si from the noise N.

[0025] One method of signal separation is based on the "data frequency" of the event data EVD for each pixel. As described above, the event data EVD includes the time at which the event was detected. Therefore, the information processing device 30 can calculate the number of event data EVD detected per unit time for each pixel. The number of event data EVD detected per unit time can be called the "data frequency."

[0026] As shown in FIG. 4, the characteristics of the optical signal Si and the noise N differ significantly in terms of data frequency. The data frequency of the optical signal Si is linked to the blinking frequency of the light source 10-i, and its value is approximately several hundred Hz to several hundred kHz. On the other hand, the data frequency of the noise N caused by the movement of the subject or the event camera 21 is significantly smaller (approximately several tens of Hz) than the data frequency of the optical signal Si. Therefore, the information processing device 30 can separate the optical signal Si from the noise N by using a frequency filter. An example of a frequency filter is a high-pass filter that cuts off signals below a preset frequency. In this case, the information processing device 30 determines that a pixel region in which a high data frequency that is not cut off by the high-pass filter is observed is a signal region occupied by the optical signal Si.

[0027] (B) in FIG. 3 is a graph showing the spatiotemporal distribution of the event data EVD after signal separation has been performed. As described above, the event data EVD includes information on coordinates in the image plane coordinate system, so the information processing device 30 can acquire the position of the separated optical signal Si in the image plane coordinate system. The position of the optical signal Si in the image plane coordinate system indicates the position where the light source 10-i is projected onto the image plane coordinate system, i.e., the light source image position IP-i. In reality, the signal area occupied by the optical signal Si on the image plane extends over multiple pixels, so for example, the center coordinate of the signal area of ​​the optical signal Si may be considered to be the light source image position IP-i. In this manner, the light source image position acquisition is performed.

[0028] 2-2. Obtaining the absolute position of the light source 5 is a schematic diagram showing some examples of acquiring the light source absolute position. As described above, the optical signal Si transmitted from the light source 10-i includes position-related information Pi for identifying the light source absolute position AP-i.

[0029] 5A, the optical signal Si transmitted from the light source 10-i includes the light source absolute position AP-i as position-related information Pi. The receiving device 20 receives the optical signal Si via the event camera 21. The receiving device 20 passes the event data EVD output by the event camera 21 to the information processing device 30. The event data EVD records the content of the optical signal Si as a change in brightness, so the information processing device 30 obtains the position-related information Pi, i.e., the light source absolute position AP-i, based on the event data EVD.

[0030] 5B, the optical signal Si includes identification information SID-i, which is information for identifying the light source 10-i. In this case, the optical wireless communication system 1 further includes a storage device 50. The storage device 50 stores absolute light source positions AP-1 to AP-n of the multiple light sources 10-1 to AP-n in association with the identification information SID-1 to AP-n of the multiple light sources 10-1 to AP-n. The information processing device 30 accesses the storage device 50 and acquires the absolute light source position AP-i corresponding to the identification information SID-i. The storage device 50 may be built into the information processing device 30 or may be an external device different from the information processing device 30. Alternatively, the storage device 50 may be managed by a management server, and the information processing device 30 may acquire the absolute light source position AP-i through communication with the management server.

[0031] 6A and 6B are diagrams showing the image plane before and after light source image position acquisition and light source absolute position acquisition are performed. (A) in Fig. 6 shows the state of the image plane before light source image position acquisition and light source absolute position acquisition are performed, i.e., at the time when the information processing device 30 acquires event data EVD. At this point, the event data EVD includes noise N as well as multiple optical signals S-1 to S-n transmitted from multiple light sources 10-1 to S-n.

[0032] The information processing device 30 separates the optical signal Si from the noise N and acquires the position of the optical signal Si in the image plane coordinate system, i.e., the light source image position IP-i of the light source 10-i. The information processing device 30 also acquires the light source absolute position AP-i of the light source 10-i through light source absolute position acquisition. As a result of the light source image position acquisition and light source absolute position acquisition, the information processing device 30 acquires a data set of the light source absolute position AP-i and the light source image position IP-i relative to the light source 10-i, as shown in (B) of FIG. 6. The information processing device 30 can estimate the position and orientation of the event camera 21 in the absolute coordinate system from these data sets and the geometric relationship based on the focal length of the event camera 21.

[0033] 2-3.Effects As described above, the receiving device 20 in the optical wireless communication system 1 includes an event camera 21. The event camera 21 detects only information related to pixels that have detected a luminance change equal to or greater than a threshold, and outputs the information as event data EVD. A frame-based sensor built into a normal camera outputs information about all pixels as an image at regular time intervals (frame rate), which tends to result in a large amount of data. On the other hand, the event camera 21 outputs only information about pixels that have experienced a luminance change, allowing for efficient detection of the optical signal Si. Therefore, the amount of event data EVD can be said to be smaller than the amount of image data output by a normal camera. If the amount of data is smaller, the time required to output the data is shorter, and therefore the event camera 21 can be said to have a higher temporal resolution than a normal camera.

[0034] Because the event camera 21 has high time resolution, the event data EVD is output at a high speed. However, because the amount of event data EVD is small, the information processing device 30 can process the event data EVD at a sufficient speed even if it does not have a particularly high performance. Consider a case where the information processing device 30 processes image data (from a frame-based sensor) output at approximately the same speed as the event data EVD in approximately the same amount of time as the event data EVD. In this case, the information processing device 30 is required to have processing performance higher than that required for processing the event data EVD. This means that in the optical wireless communication system 1, camera position estimation can be performed even if the information processing device 30 does not have particularly high processing performance.

[0035] Furthermore, it is more effective to use visible light sources as the multiple light sources 10-1 to 10-n. One advantage of using visible light sources is that they are widely used in existing facilities (street lights, indoor lights, traffic lights, electronic billboards, etc.), so their use requires less capital investment. However, because visible light has a higher frequency than radio waves and infrared rays, there is a concern that a normal camera may not be able to measure the data frequency. On the other hand, because the event camera 21 has high time resolution as mentioned above, a synergistic effect can be expected when combined with high-frequency visible light.

[0036] Furthermore, in the optical wireless communication system 1, even if the event camera 21 moves, tracking of images of the multiple light sources 10-1 to 10-N is not required.

[0037] Consider Patent Document 1 as a comparative example for a case where a camera moves within a system that estimates position and orientation from camera images. FIG. 7 is a diagram showing the comparative example. Patent Document 1 discloses a method for estimating the position and orientation of a camera using a fixed, blinking light-emitting point and a camera (frame-based camera). Furthermore, when the camera moves, the system tracks the light-emitting point moving within the image to detect the blinking pattern of the same light-emitting point. The system disclosed in Patent Document 1 tracks each light-emitting point by predicting the detection position in the next frame of a light-emitting point detected in a certain frame and associating it with light-emitting points located within a predetermined range from the predicted detection position in the next frame. Tracking in image processing can be said to be a process that imposes a large processing load.

[0038] On the other hand, in the optical wireless communication system 1, high-speed communication is possible by receiving the high-speed blinking of the multiple light sources 10-1 to 10-n with the event camera 21, which has high time resolution. That is, since camera position estimation is completed in an extremely short time, it is only necessary to continue measuring the data frequency for each pixel, ignoring the movement of the multiple light sources 10-1 to 10-n on the image plane. That is, since tracking is not necessary in the optical wireless communication system 1, the processing load imposed on the information processing device 30 can be reduced. This leads to a further reduction in the processing performance required of the information processing device 30.

[0039] Furthermore, Patent Document 1 requires a feature point (that does not flicker) that is fixed in the imaging space and has a predetermined brightness. This feature point is necessary for stable tracking of the light-emitting point. Because the feature point does not flicker, stable tracking is possible. Patent Document 1 improves the accuracy of tracking of the light-emitting point by utilizing the fact that the movement of the light-emitting point in the image is linked to the movement of the feature point in the image, as shown in FIG. 7. For example, if there is no feature point, it is not necessarily easy to track the light-emitting point during a frame in which the light-emitting point is off and calculate the position where the light-emitting point will appear the next time it lights up. Therefore, Patent Document 1 predicts the position where the light-emitting point will next appear when it lights up by using tracking of the feature point. In other words, feature points are necessary for stable tracking of the light-emitting point, but are unnecessary elements for the optical wireless communication system 1, which does not require tracking. By using the event camera 21, the optical wireless communication system 1 can be said to reduce the components required for camera position estimation.

[0040] 3. Example of optical communication system configuration 3-1. First example FIG. 8 is a block diagram showing a first configuration example of the optical wireless communication system 1. As shown in FIG.

[0041] The blinking control device 60 controls the blinking pattern of the light source 10-i. The blinking control device 60 may be built into each facility (street light, indoor light, etc.) that includes the light source 10-i. Alternatively, the blinking control device 60 may be included in an external facility (such as a management server) and control the blinking of the light source 10-i from outside. Furthermore, when the blinking control device 60 is provided in an external facility, it may collectively control the blinking of multiple light sources 10-1 to 10-n.

[0042] The information generating unit 61 generates a digital signal D. The digital signal D is a signal that represents the position-related information Pi using two values, “0” and “1.” The generated digital signal D is output to the modulation unit 62.

[0043] The modulator 62 generates a modulated signal M by modulating the digital signal D into a signal suitable for optical wireless communication. As a modulation method, a pulse width modulation (PWM) method, a pulse position modulation (PPM) method, or the like is used. The PWM method is a method in which the ratio of the ON (on) and OFF (off) time of the light source 10-i is changed by an input signal. The PPM method is a modulation method in which the position of the carrier pulse on the time axis is changed by an input signal.

[0044] The blinking control device 60 passes the modulation signal M to the light source 10-i. The light source 10-i blinks in accordance with the modulation signal M. The optical signal Si is a signal indicated by the blinking pattern of the light source 10-i expressed by the modulation signal M.

[0045] The receiving device 20 receives the optical signal Si through the event camera 21. Specifically, an EV sensor built into the event camera 21 detects a change in brightness due to the optical signal Si as an event. The receiving device 20 transmits the event data EVD to a signal separation unit 31 in the information processing device 30.

[0046] 8, the information processing device 30 is a device (e.g., an external server) different from the receiving device 20. That is, the receiving device 20 transmits event data EVD to the external information processing device 30. The information processing device 30 executes a series of subsequent processes based on the received event data EVD.

[0047] The signal separation unit 31 acquires the light source image position IP-i by performing the process (the signal separation described above) of separating the optical signal Si and the noise N included in the event data EVD. The light source image position IP-i is output to the position estimation unit 33.

[0048] The demodulator 32 demodulates the optical signal Si separated by the signal separator 31 to obtain the position-related information Pi. The demodulator 32 passes the position-related information Pi to the position estimator 33.

[0049] The position estimation unit 33 acquires the light source absolute position AP-i based on the position relation information Pi. For example, as in (A) of FIG. 5, when the light source absolute position AP-i is directly transmitted as the position relation information Pi, the position estimation unit 33 directly acquires the light source absolute position AP-i. Also, as in (B) of FIG. 5, when the identification information SID-i is transmitted as the position relation information Pi, the information processing device 30 accesses the storage device 50 and acquires the light source absolute position AP-i corresponding to the identification information SID-i. The information processing device 30 acquires n sets of data sets of the light source absolute position AP-i and the light source image position IP-i relative to the light source 10-i. The information processing device 30 estimates the position and orientation of the event camera 21 in the absolute coordinate system from the geometric relationship between these n sets of data sets.

[0050] 3-2. Second example Fig. 9 is a block diagram showing a second configuration example of the optical wireless communication system 1. The basic configuration is similar to the example in Fig. 8. In the example in Fig. 9, the information processing device 30 is built into the receiving device 20. In this case, after receiving the optical signal Si, the receiving device 20 can complete camera position estimation within the receiving device 20.

[0051] 3-3.Other examples In addition to the above, various other configurations are possible for the receiving device 20 and the information processing device 30. For example, the functions of the signal separation unit 31 and the demodulation unit 32 may be included in the receiving device 20, and the function of the position estimation unit 33 may be included in the information processing device 30 external to the receiving device 20. [Explanation of symbols]

[0052] 1: Optical wireless communication system 10-i: Light source 20: Receiving device 21: Event Camera 30: Information processing device 31: Signal separation section 32: Demodulation section 33:Position estimation part 50: Storage device 60: Blinking control device 61: Information generation section 62: Modulation section AP-i: Light source absolute position D: Digital signal EVD: Event Data IP-i: Light source image position M: Modulation signal N: Noise Pi: Location-related information Si: Optical signal SID-i: Identification information

Claims

1. The system includes a plurality of light sources, a receiving device having an event camera, and an information processing device, each of the plurality of light sources transmits an optical wireless communication signal; the receiving device receives the optical wireless communication signal through the event camera; the optical wireless communication signal includes position-related information for identifying a position in an absolute coordinate system of a source of the optical wireless communication signal; The information processing device includes: acquiring light source image positions indicating positions where each of the plurality of light sources is projected onto the image plane coordinate system by identifying a signal region of the optical wireless communication signal in an image plane coordinate system of an image plane obtained by the event camera; acquiring a light source absolute position indicating a position of each of the plurality of light sources in the absolute coordinate system based on the position related information included in the optical wireless communication signal; The light source image position and the light source absolute position are used to estimate the position and orientation of the event camera in the absolute coordinate system. It was configured as Optical wireless communication system.

2. 2. The optical wireless communication system according to claim 1, The information processing device identifies the signal region in the image plane coordinate system based on a frequency of event data for each pixel on the image plane obtained by the event camera. Optical wireless communication system.

3. 2. The optical wireless communication system according to claim 1, The position-related information includes the absolute light source position of each of the plurality of light sources. Optical wireless communication system.

4. 2. The optical wireless communication system according to claim 1, Further comprising a storage device; The storage device includes at least Identification information for identifying each of the plurality of light sources; the light source absolute position of each of the plurality of light sources; Store the position-related information includes the identification information of each of the plurality of light sources; The information processing device acquires the light source absolute position corresponding to the identification information included in the position relation information from the storage device. Optical wireless communication system.

5. 5. An optical wireless communication system according to claim 1, The receiving device is not fixed in space. Optical wireless communication system.

6. Event cameras and an information processing device that receives, through the event camera, optical wireless communication signals transmitted from each of a plurality of light sources; Equipped with the optical wireless communication signal includes position-related information for identifying a position in an absolute coordinate system of a source of the optical wireless communication signal; The information processing device includes: acquiring light source image positions indicating positions where each of the plurality of light sources is projected onto the image plane coordinate system by identifying a signal region of the optical wireless communication signal in an image plane coordinate system of an image plane obtained by the event camera; acquiring a light source absolute position indicating a position of each of the plurality of light sources in the absolute coordinate system based on the position related information included in the optical wireless communication signal; The light source image position and the light source absolute position are used to estimate the position and orientation of the event camera in the absolute coordinate system. It was configured as Receiving device.

7. 7. The receiving device according to claim 6, 2. The optical wireless communication system according to claim 1, The information processing device identifies the signal region in the image plane coordinate system based on a frequency of event data for each pixel on the image plane obtained by the event camera. Receiving device.

8. 7. The receiving device according to claim 6, The position-related information includes the absolute light source position of each of the plurality of light sources. Receiving device.

9. 7. The receiving device according to claim 6, Further comprising a storage device; The storage device includes at least Identification information for identifying each of the plurality of light sources; the light source absolute position of each of the plurality of light sources; Store the position-related information includes the identification information of each of the plurality of light sources; The information processing device acquires the light source absolute position corresponding to the identification information included in the position relation information from the storage device. Receiving device.

10. 10. The receiving device according to claim 6, Not fixed in space Receiving device.

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