Patent ID: 12210124

EXAMPLE EMBODIMENT

Hereinafter, example embodiments of the present invention will be described with reference to the drawings. However, the example embodiments described below have technically preferable limitations for performing the present invention, but the scope of the invention is not limited to the following. In all the drawings used in the following description of the example embodiments, the same reference signs are given to the same parts unless there is a particular reason. In the following example embodiments, repeated description of similar configurations and operations may be omitted.

First Example Embodiment

First, a management system according to a first example embodiment will be described with reference to the drawings. The management system of the present example embodiment includes a monitoring device and at least one detection device installed on a monitoring target. The monitoring device manages a positional relationship of at least one detection device located in a monitored space based on the image obtained by imaging the monitored space.

(Configuration)

FIG.1is a conceptual diagram illustrating an example of a configuration of a management system1according to the present example embodiment. The management system1includes a monitoring device10and at least one detection device16. The detection device16is installed on at least one monitoring target (not illustrated). Note that the management system1may include a plurality of monitoring devices10, and the plurality of monitoring devices10may be configured to cooperate with each other.

The monitoring device10projects the detection light toward a projection target surface180. A monitored space181monitored by the monitoring device10is formed between the monitoring device10and the projection target surface180. The monitoring device10receives reflected light from the detection device16located in the monitored space181. When receiving the reflected light from the detection device16, the monitoring device10determines that the detection device16is located in monitored space181.

Upon receiving the reflected light from the detection device16, the monitoring device10images the monitored space181at a predetermined timing in a predetermined period starting from the reception of the reflected light while continuing the projection of the detection light. The predetermined timing at which the monitoring device10images the monitored space181is a timing commonly set in advance for all the detection devices16installed on the monitoring target. The monitoring device10identifies an identification number unique to the detection device16located in the monitored space181based on a detection pattern of the reflected light from the detection device16using a plurality of captured images. The monitoring device10associates identified identification numbers with positions on the image to specify positions of the detection devices16.

The detection device16is mounted on a monitoring target. An identification number unique to each individual is assigned to each of the detection devices16. For example, when the number of monitoring targets is 32, any one of identification numbers of 0 to 31 is assigned to each of the detection devices16. When receiving the detection light projected by the monitoring device10, the detection device16reflects the detection light at a timing set in advance in accordance with each identification number in a predetermined period starting from the reception of the detection light. The timing at which each detection device16reflects the detection light is set according to each identification number, and is unique to each detection device16. For example, the timing at which the detection device16reflects the detection light and the timing at which the monitoring device10receives the reflected light of the detection light are adjusted according to the distance between the detection device16and the monitoring device10.

In the management system1of the present example embodiment, the position of the monitoring target on which each detection device16is mounted is associated with the position on the image based on the plurality of images obtained by capturing the reflected light by at least one detection device16. Therefore, according to the management system1of the present example embodiment, the positional relationship of the monitoring target can be managed.

Next, details of configurations of the monitoring device10and the detection device16included in the management system1will be described with reference to the drawings. The following configurations of the monitoring device10and the detection device16are merely examples, and do not limit the configurations of the monitoring device10and the detection device16.

[Monitoring Device]

FIG.2is a block diagram illustrating an example of the monitoring device10included in the management system1. The monitoring device10includes a projector11, a projection control unit13, a reflected light receiver14, and an identification unit15. The projection control unit13and the identification unit15constitute a monitoring control unit12.

The projector11is a projector including a spatial light modulator. The projector11projects the detection light under the control of the projection control unit13. In the present example embodiment, the projector11projects detection light having a wavelength in an infrared region. The spatial light modulator of the projector11includes a modulation unit that displays a pattern according to the detection light to be projected. The light emitted to the modulation unit in a state where the pattern relevant to the detection light is displayed is modulated when reflected by the modulation unit. The light modulated by the modulation unit is projected toward the projection target surface180as detection light via a projection optical system.

The projection control unit13causes the modulation unit of the spatial light modulator of the projector11to display a pattern relevant to the detection light. The projection control unit13controls the emission timing of the light source of the projector11in a state where the pattern relevant to the detection light is displayed on the modulation unit, and causes the projector11to irradiate the modulation unit with light.

The reflected light receiver14includes a two-dimensional sensor sensitive to the infrared region. The reflected light receiver14images a range including the monitored space181. For example, the reflected light receiver14images the reflected light reflected by the detection device16by a two-dimensional sensor. The reflected light receiver14outputs the captured image to the identification unit15. Under the control of the identification unit15, the reflected light receiver14images the monitored space181at a predetermined timing in a predetermined period starting from the timing at which the reflected light is received. The reflected light receiver14outputs the plurality of captured images to the identification unit15.

The identification unit15acquires an image captured by the reflected light receiver14. When detecting the reflected light from the acquired image, the identification unit15detects the position of the reflected light. The identification unit15causes the reflected light receiver14to image the monitored space181at a preset timing for a predetermined period from the timing at which the reflected light is detected. The timing at which the reflected light receiver14images the monitored space181is set in accordance with the timing at which the reflected light reflected by the detection device16is received by the reflected light receiver14. For example, the identification unit15causes the reflected light receiver14to image the monitored space181at a preset time interval in accordance with the timing at which the reflected light receiver14receives the reflected light.

The identification unit15identifies the identification number of the detection device16that is the reflection source of the reflected light by the detection pattern of the reflected light at the same position on the plurality of images captured by the reflected light receiver14. The identification unit15associates the position on the image captured by the reflected light receiver14with the identification number to specify the position of the detection device16.

For example, identification numbers of 0 to 31 are assigned in advance to each of the plurality of detection devices16. Then, each detection device16is set so that the detection light is reflected at the timing when the identification number of each detection device16matches the logical value of the bit (0, 1) expressed in binary number. For example, the detection device16is set so as not to reflect the detection light when the logic value is 0 and to reflect the detection light when the logic value is 1. For example, when the identification numbers of the detection devices16are 0 to 31, five imaging timings are set in accordance with the number of bits (5) in a predetermined period. When the reflected light is not detected at the first timing and the reflected light is detected at the second to fifth timings at a certain position, the identification unit15identifies that the detection device16with the identification number 15 (01111 in the binary number) is located at the position. The detection device16may be set so as not to reflect the detection light when the logic value is 1, and to reflect the detection light when the logic value is 0. The timing of reflection by detection device16according to the identification number may be set in ascending order of the identification number, or may be set in descending order of the identification number.

<Projector>

FIG.3is a conceptual diagram for explaining a configuration of the projector11. The projector11includes a light source120, a spatial light modulator130, and a projection optical system140. Note thatFIG.3is conceptual, and does not accurately represent the positional relationship between the components, the light irradiation direction, and the like.

The light source120includes an emitter121that emits laser light101having a wavelength in an infrared region, and a collimator123that converts the laser light101emitted from the emitter121into parallel light102. The emitter121emits the laser light101having a wavelength in the infrared region under the control of the projection control unit13. The laser light101emitted from the emitter121is converted into the parallel light102by the collimator123, and emitted from the light source120. The parallel light102emitted from the light source120travels toward the modulation unit of the spatial light modulator130.

For example, the emitter121emits infrared light in a 1.0 micrometer band or a 1.5 micrometer band from the viewpoint of eye safety. The wavelength region of the laser light101emitted from the emitter121is not limited to a 1.0 micrometer band or a 1.5 micrometer band. The emitter121may be configured to emit light of a plurality of wavelength regions instead of a single wavelength region.

As illustrated inFIG.3, the incident angle of the parallel light102is made non-perpendicular to the irradiation surface of the modulation unit of the spatial light modulator130. That is, the emission axis of the parallel light102emitted from the light source120is inclined with respect to the irradiation surface of the modulation unit of the spatial light modulator130. If the emission axis of the parallel light102is set obliquely with respect to the irradiation surface of the modulation unit of the spatial light modulator130, the parallel light102can be incident on the irradiation surface of the modulation unit of the spatial light modulator130without using a beam splitter. Therefore, light utilization efficiency can be improved. If the emission axis of the parallel light102is set obliquely with respect to the irradiation surface of the modulation unit of the spatial light modulator130, the size of the projector11can be made compact.

The spatial light modulator130includes a modulation unit irradiated with the parallel light102. In the modulation unit of the spatial light modulator130, a pattern relevant to the detection light is set under the control of the projection control unit13. For example, the spatial light modulator130is achieved by a spatial light modulator using ferroelectric liquid crystal, homogeneous liquid crystal, vertical alignment liquid crystal, or the like. For example, the spatial light modulator130can be achieved by liquid crystal on silicon (LCOS). The spatial light modulator130may be achieved by a micro electro mechanical system (MEMS). If the laser light in the infrared region is emitted, the MEMS is more suitable than the LCOS.

FIG.4is a conceptual diagram for explaining an example (MEMS130-1) of the MEMS that achieves the spatial light modulator130. The MEMS130-1has a structure in which a plurality of small mirrors135is installed in a lattice shape for each pixel on a surface (modulation unit) that modulates the laser light. In the case of using the MEMS130-1, the emitted parallel light102is modulated by displacing the height of each of the plurality of small mirrors135in the Z direction based on the control of the projection control unit13.

On the modulation unit of the spatial light modulator130, a plurality of reflection regions (relevant to pixels) capable of changing optical characteristics such as a refractive index are arrayed in an array. The spatial light modulator130sets optical characteristics of each pixel of the modulation unit under the control of the projection control unit13, and sets a pattern for displaying a desired image on the projection target surface in the modulation unit. When the modulation unit in a state where the pattern is set is irradiated with light, the modulated light103in which the spatial distribution is modulated according to the optical characteristics of the modulation unit is emitted. For example, a modulator that modulates a spatial distribution such as a phase, an amplitude, an intensity, a polarization state, a propagation direction, and the like of light can be used as the spatial light modulator130.

For example, the spatial light modulator130can be achieved by a phase modulation type spatial light modulator that modulates the phase of the incident parallel light102. In a case where the spatial light modulator130is of a phase modulation type, a phase image relevant to an image to be displayed on the projection target surface is set in the modulation unit. The phase image is an image in which a pattern relevant to an image to be displayed on the projection target surface is arranged in a tile shape. Since the phase modulation type spatial light modulator130is focus-free, it is not necessary to change the focus according to the projection distance even if light is projected on a plurality of display regions having different projection distances. By using the phase modulation type spatial light modulator130, energy can be concentrated on a portion of a line constituting an image by sequentially switching a region where the spatial light signal is projected. Therefore, if the outputs of the light sources120are the same, by using the phase modulation type spatial light modulator130, it is possible to display an image brighter than a method of collectively transmitting light onto the entire display region.

The modulation unit of the spatial light modulator130is irradiated with the parallel light102from the light source120under the control of the projection control unit13. The modulation unit of the spatial light modulator130is irradiated with the parallel light102in a state in which a pattern according to the detection light is set in accordance with the timing of emitting the detection light. As a result, the modulated light103modulated by the modulation unit of the spatial light modulator130is emitted toward the projection optical system140.

The projection optical system140is an optical system that projects the modulated light103obtained as a result of modulation by the spatial light modulator130as detection light105. As illustrated inFIG.3, the projection optical system140includes a Fourier transform lens146, an aperture147, and a projection lens148.

The Fourier transform lens146is an optical lens that forms an image formed when the modulated light103obtained as a result of modulation by the modulation unit of the spatial light modulator130is projected at infinity, at a focal position near the aperture147.

The aperture147is a frame for shielding high-order light included in the light focused by the Fourier transform lens146and restricting an outer edge of a display region. The opening of the aperture147is opened smaller than the outer periphery of the display region at the position of the aperture147, and is installed to shield the peripheral region of the image at the position of the aperture147. For example, the opening of the aperture147is formed in a rectangular shape or a circular shape. The aperture147is preferably provided at the focal position of the Fourier transform lens146, but may be shifted from the focal position of the Fourier transform lens146as long as the display region can be restricted.

The projection lens148is an optical lens that enlarges the light focused by the Fourier transform lens146. The projection lens148enlarges the detection light105such that an image relevant to the phase image set in the modulation unit of the spatial light modulator130is formed on the projection target surface.

FIG.5is a conceptual diagram illustrating an example in which the projector11projects the detection light105to linearly scan the projection target surface180. In the example ofFIG.5, the projector11projects the detection light105in a first region s1, a second region s2, . . . , and an n-th region sn, in this order toward the projection target surface180divided into n equal parts.

FIG.6is a conceptual diagram illustrating an example in which the projector11planarly projects the detection light105on the projection target surface180. In the example ofFIG.6, the projector11collectively projects the detection light105toward the entire surface of the projection target surface180.

When the output of the light source120of the projector11is the same, the output of the detection light105can be set higher in the case of projecting the detection light105so as to scan linearly (FIG.5) than in the case of projecting the detection light105in a planar manner (FIG.6). On the other hand, the detection time is longer in the case of projecting the detection light105to scan linearly (FIG.5) than in the case of projecting the detection light105in a planar manner (FIG.6). Therefore, the detection light105projected from the projector11is preferably set according to a request for the output of the light source120, the detection time, and the like.

<Projection Control Unit>

FIG.7is a block diagram illustrating an example of a configuration of the projection control unit13. The projection control unit13includes a projection condition storage unit131, a projection condition setting unit132, a modulator control unit133, and a light source control unit134.

The projection condition storage unit131stores a pattern according to the detection light105. In a case where the spatial light modulator130of the projector11is of a phase modulation type, the projection condition storage unit131stores a phase distribution according to the detection light105. The projection condition storage unit131stores a projection condition including a light source control condition for controlling the light source120and a modulation element control condition for controlling the spatial light modulator130.

The projection condition setting unit132sets a projection condition for projecting the detection light105. That is, the projection condition setting unit132sets, in the modulator control unit133, a modulation element control condition for setting a pattern according to the detection light105in the modulation unit of the spatial light modulator130. The projection condition setting unit132sets, in the light source control unit134, a light source control condition for emitting the laser light101from the light source120. The projection condition setting unit132matches the timing at which the modulation element control condition is set in the modulator control unit133with the timing at which the light source control condition is set in the light source control unit134. As a result, the display part of the spatial light modulator130in a state where the pattern according to the detection light is displayed is irradiated with the laser light101emitted from the light source120.

For example, the projection condition setting unit132sets a light source control condition for continuously emitting the laser light101in the emitter121for a predetermined period from the timing at which the reflected light is received. The projection condition setting unit132may set the light source control condition for causing the emitter121to emit the laser light101in a pulsed manner in the emitter121in accordance with the timing at which the detection device16reflects the detection light105during a predetermined period from the timing at which the reflected light is received. For example, the projection condition setting unit132sets a light source control condition for emitting the laser light101in the nanosecond order in the emitter121. When the laser light101in the nanosecond order is emitted from the emitter121, the output can be instantaneously greatly increased. The contrast can be improved by shortening the integration time in synchronization with the timing at which the reflected light of the pulsed laser light101is received by the reflected light receiver14and avoiding integrating the ambient light during the time during which the reflected light is not received by the reflected light receiver14.

The projection condition setting unit132acquires a pattern according to the detection light105and a modulation element control condition which is a condition for setting the pattern in the modulation unit of the spatial light modulator130from the projection condition storage unit131. For example, when the spatial light modulator130of the projector11is of a phase modulation type, the projection condition setting unit132sets the phase distribution on the display part of the spatial light modulator130as a pattern according to the detection light105.

For example, the projection condition setting unit132may set, in the spatial light modulator130, the modulation element control condition for selectively projecting the detection light105toward the position where the reflected light is detected for a predetermined period from the timing at which the reflected light is received. By restricting the projection direction of the detection light105to the position where the reflected light is detected, the irradiation range of the detection light105can be narrowed, so that power consumption in a predetermined period from the timing at which the reflected light is received can be reduced. If the projection direction is restricted, the output of the detection light105projected toward the position where the reflected light is detected can be set high.

The modulator control unit133receives the pattern according to the detection light105and the modulation element control condition from the projection condition setting unit132. The modulator control unit133drives a driver (not illustrated) that changes the pattern set in the modulation unit of the spatial light modulator130according to the modulation element control condition received from the projection condition setting unit132. As a result, a pattern according to the detection light105is set in the modulation unit of the spatial light modulator130.

The light source control unit134is connected to the projection condition setting unit132and the light source120. The light source control unit134drives a driving unit (not illustrated) of the emitter121according to the light source control condition received from the projection condition setting unit132. As a result, the laser light101is emitted from the emitter121. As a result, the modulation part of the spatial light modulator130is irradiated with the parallel light102caused by the laser light101in accordance with the timing at which the pattern is set in the modulation unit of the spatial light modulator130, and the detection light105relevant to the pattern displayed on the modulation unit of the spatial light modulator130is projected.

<Reflected Light Receiver>

FIG.8is a conceptual diagram illustrating an example of a configuration of the reflected light receiver14. The reflected light receiver14includes a filter141, a lens142, a two-dimensional sensor143, a converter144, and an image processing unit145.

The filter141is an infrared light transmitting filter that reflects light in a visible region from received light and selectively transmits reflected light in an infrared region reflected by the detection device16. The wavelength region selected by the filter141is set in accordance with the wavelength region of the reflected light from the detection device16. The reflected light transmitted through the filter141is guided to the lens142. When the two-dimensional sensor143can selectively receive light in the infrared region, the filter141may be omitted.

The lens142is an optical lens that focuses the reflected light having passed through the filter141on the light receiving surface of the two-dimensional sensor143. For example, a lens made of a material such as sapphire, calcium fluoride, barium fluoride, zinc selenide, zinc sulfide, chalcogenide glass, or plastic can be used as the lens142. When long-wavelength infrared light is used, a lens made of a material such as germanium or silicon may be used as the lens142.

The reflected light of the infrared region focused by the lens142is incident on the two-dimensional sensor143. The two-dimensional sensor143is a sensor in which elements that convert reflected light in an infrared region into electric signals are installed in a lattice shape. The two-dimensional sensor143outputs the converted electric signal to the converter144.

The two-dimensional sensor143is not particularly limited as long as it has sensitivity to light in an infrared region. For example, as the two-dimensional sensor143, an imaging element having high sensitivity to a wavelength in a near-infrared region, such as an indium-gallium-arsenide type, an indium-antimony type, or a type2superlattice type, can be used. For example, an imaging element such as an indium-gallium-arsenide type, an indium-antimony type, a type2superlattice type, a mercury-cadmium-tellurium type, a bolometer type, or a pyroelectric type can be used as the two-dimensional sensor143. A general-purpose two-dimensional sensor143for visible light may be used as the two-dimensional sensor143as long as it has sensitivity to the wavelength of the detection light105.

The converter144obtains an electric signal from the two-dimensional sensor143. The converter144converts the acquired electric signal from analog to digital. The converter144outputs the electric signal converted into digital to the image processing unit145.

The image processing unit145acquires the electric signal converted into digital from the converter144. The image processing unit145generates image data of the monitored space181using the acquired electric signal. The image processing unit145outputs the generated image data to the identification unit15.

<Identification Unit>

FIG.9is a block diagram illustrating an example of a configuration of the identification unit15. The identification unit15includes a reflected light detection unit151, an imaging control unit152, an identification information identification unit153, and an identification information storage unit154.

The reflected light detection unit151acquires image data from the reflected light receiver14. The reflected light detection unit151detects reflected light from the acquired image data. When detecting the reflected light from the image data, the reflected light detection unit151issues an imaging instruction to the imaging control unit152. For example, when the number of bits of the identification number assigned to each of the detection devices16to be monitored is 5, an imaging instruction to perform imaging five times at a predetermined timing is issued to the imaging control unit152in a predetermined period from the timing at which the reflected light is detected. The reflected light detection unit151detects the position of the reflected light from the plurality of pieces of image data captured according to the imaging instruction in order of imaging, and outputs the detected position to the identification information identification unit153in order.

In response to the imaging instruction from the reflected light detection unit151, the imaging control unit152controls the reflected light receiver14to perform imaging at a predetermined timing in a predetermined period from the timing at which the reflected light is detected. For example, when the number of bits of the identification number assigned to each of the detection devices16to be monitored is 5, the imaging control unit152controls the reflected light receiver14to perform imaging five times at a predetermined timing in a predetermined period from the timing at which the reflected light is detected.

The identification information identification unit153acquires the positions of the reflected light detected from the plurality of pieces of image data from the reflected light detection unit151in the order of imaging. The identification information identification unit153identifies the identification number of the detection device16based on the detection pattern of the reflected light detected at the same position on the image. For example, in a case where the number of bits of the identification number is 5, the timing at which the reflected light is detected at five imaging timings is set to 1, and the timing at which the reflected light is not detected is set to 0. For example, if the first time is 1, the second time is 0, the third time is 1, the fourth time is 0, and the fifth time is 1, the identification information identification unit153identifies the detection device16with the identification number 21 (10101 in the binary number).

The identification information storage unit154stores identification information including identification numbers associated with the plurality of detection devices16. The identification information stored in the identification information storage unit154is referred to by the identification information identification unit153.

[Detection Device]

FIGS.10and11are conceptual diagrams illustrating an example of a configuration of the detection device16. The detection device16includes a shutter161, a reflector162, a receiver163, an opening and closing control unit164, and an opening and closing condition storage unit165.

The shutter161is installed to face the reflecting surface of the reflector162. The shutter161is opened and closed under the control of the opening and closing control unit164.FIG.10illustrates a state where the shutter161is opened, andFIG.11illustrates a state where the shutter161is closed. As illustrated inFIG.10, when the shutter161is opened, the detection light enters the reflector162. As illustrated inFIG.11, when the shutter161is closed, the detection light is shielded by the shutter161and is not incident on the reflector162. In the present example embodiment, it is assumed that the shutter161is open in the initial state. The shutter161may extend to a position facing the light receiving surface of the receiver163. For example, the shutter161can be achieved by a flexible liquid crystal element.

The reflector162has a reflecting surface that reflects the detection light. The reflector162is installed such that the reflecting surface faces the shutter161. The reflector162reflects the detection light incident on the reflecting surface toward the monitoring device10. For example, the reflector162is achieved by a retroreflector that retroreflects the detection light. Although not illustrated inFIG.10, it is preferable to install an infrared light transmitting filter similar to the filter141of the reflected light receiver14between the reflecting surface of the reflector162and the shutter161.

FIG.12is a conceptual diagram illustrating an example of a retroreflector (retroreflector190) that achieves the reflector162. The retroreflector190includes a substrate191, a spherical bead192, a focus layer193, and a reflection layer194. A plurality of spherical bead192having a high refractive index is placed on one surface (hereinafter, referred to as an incident surface) of the substrate191of the retroreflector190. For example, the spherical bead192is glass beads having a refractive index larger than that of general glass. On the back side of the plurality of spherical beads192installed on the incident surface of the retroreflector190, a focus layer193in which light incident from the incident surface side is focused is installed. On the back side of the focus layer193, a reflection layer194for reflecting light focused on the focus layer193is installed. For example, the reflection layer194can be formed by depositing metal such as aluminum on the incident surface side of the substrate191.

The light incident on the retroreflector190is refracted by the surface of the spherical bead192and travels inside the spherical bead192. The light reaching the back surface (the focus layer193side) of the spherical bead192is refracted by the back surface of the spherical bead192and focused in the focus layer193. When the light focused on the focus layer193is reflected by the reflection layer194and the reflected light reaches the back surface of the spherical bead192, the light is refracted by the back surface and travels inside the spherical bead192. The light having reached the surface of the spherical bead192is refracted by the surface and emitted toward the incident direction.

The receiver163is a photodetector that receives detection light. An opening is formed on the light receiving surface side of the receiver163. The receiver163converts the received detection light into an electric signal. The receiver163outputs the converted electric signal to the opening and closing control unit164.

For example, the receiver163can be achieved by an element such as a photodiode or a phototransistor. The receiver163achieved by an avalanche photodiode can support high-speed communication. The receiver163may be achieved by an element other than a photodiode, a phototransistor, or an avalanche photodiode as long as it can convert an optical signal into an electric signal.

The receiver163receives light in a wavelength region of the detection light. In the present example embodiment, the receiver163receives detection light in an infrared region. It is sufficient that the receiver163is selected in accordance with the wavelength of the detection light projected from the monitoring device10. The receiver163is sensitive to light having a wavelength in the 1.0 micrometer band or the 1.5 micrometer band, for example. For example, the 1.0 micrometer band is a wavelength region of 0.84 to 0.95 micrometers. The wavelength band of the light detected by the receiver163is not limited to the 1.0 micrometer band or the 1.5 micrometer band. The wavelength band of the light detected by the receiver163may be set to, for example, a 0.8 micrometer band, a 1.55 micrometer band, or a 2.2 micrometer band. The wavelength band of the optical signal detected by the receiver163may be, for example, a 0.8 to 1.0 micrometer band. The receiver163may be sensitive to a plurality of wavelength regions.

The opening and closing control unit164receives an electric signal from the receiver163. When receiving the electric signal, the opening and closing control unit164performs opening and closing control of the shutter161based on the opening and closing condition stored in the opening and closing condition storage unit165.

FIG.13is a conceptual diagram illustrating an example of the opening and closing timing of the shutter161of the detection device16with the identification number 21. When the receiver163receives the detection light, the opening and closing control unit164controls opening and closing of the shutter161in accordance with a predetermined timing in a predetermined period starting from timing to at which the detection light is received. The predetermined timing includes timing t1, timing t2, timing t3, timing t4, and timing t5.

In the example ofFIG.13, the opening and closing control unit164controls opening and closing of the shutter161in the order of opening (1), closing (0), opening (1), closing (0), and opening (1) based on the opening and closing condition stored in the opening and closing condition storage unit165. As a result, the reflector162reflects the reflected light at the time of opening (1) and does not reflect the reflected light at the time of closing (0). The monitoring device10identifies that the reflection source of the detected reflected light is the detection device16of the identification number 21 according to the light reception timing of the reflected light in a predetermined period.

The opening and closing condition storage unit165stores the opening and closing condition of the shutter161set in the detection device16. For example, in the case of the identification number 21 of the detection device16, the opening and closing condition storage unit165of the detection device16stores the opening and closing condition for controlling opening and closing of the shutter161in the order of opening (1), closing (0), opening (1), closing (0), and opening (1).

Application Example

FIG.14is a conceptual diagram for explaining an application example in which the management system1is applied to management of a plurality of monitoring targets inside a factory. In the example ofFIG.14, detection devices16with the identification numbers 15, 16, 21, 28, and 30 are located in the monitored space181. The detection device16with the identification number 15 is installed in an upper part of an operating room of a crane. The detection device16with the identification number 16 is installed in a hook portion of the crane. The detection devices16with the identification numbers 21 and 30 are installed on the top of a helmet of a worker. The detection device16with the identification number 28 is installed in an upper part of a cab of a forklift.

FIG.15is a conceptual diagram illustrating a positional relationship between the detection device16and the monitoring device10projected on the projection target surface180when the monitored space181is viewed from above. An x-axis and a y-axis orthogonal to each other are set on the projection target surface180. For example, the position on the projection target surface180can be expressed by an xy coordinate system set on the projection target surface180. InFIG.15, a place where the monitoring target cannot pass is shaded. For example, when a place where the monitoring target cannot pass is known in advance, the detection light may be projected while avoiding the place where the monitoring target cannot pass.

FIG.16is an example of an image obtained by capturing the monitored space181. InFIG.16, the position where the reflected light is detected is filled in black. InFIG.16, the coordinates of the position where the reflected light is detected and the identification number of the detection device16located at the position coordinates are also written.

FIG.17is a time chart for explaining a timing at which the plurality of detection devices16controls opening and closing of the shutter161in a predetermined period starting from the timing to at which the reflected light is detected. Each detection device16controls opening and closing of the shutter161in accordance with a predetermined timing (timing t1, timing t2, timing t3, timing t4, and timing t5). In other words, each detection device16controls opening and closing of the shutter161in the arrangement order of the logical values of the bits when the identification number set in the detection device is expressed in the binary number.

The opening and closing control unit164of the detection device16with the identification number 15 controls opening and closing of the shutter161in the order of closing (0), opening (1), opening (1), opening (1), and opening (1). The opening and closing control unit164of the detection device16with the identification number 16 controls opening and closing of the shutter161in the order of opening (1), closing (0), closing (0), closing (0), and closing (0). The opening and closing control unit164of the detection device16with the identification number 21 controls opening and closing of the shutter161in the order of opening (1), closing (0), opening (1), closing (0), and opening (1). The opening and closing control unit164of the detection device16with the identification number 28 controls opening and closing of the shutter161in the order of opening (1), opening (1), opening (1), closing (0), and closing (0). The opening and closing control unit164of the detection device16with the identification number 30 controls opening and closing of the shutter161in the order of opening (1), opening (1), opening (1), opening (1), and closing (0).

FIG.18is a conceptual diagram illustrating an example of reflected light detected on an image captured by the monitoring device10at each of timing to, timing t1, timing t2, timing t3, timing t4, and timing t5. It is indicated that the reflected light is not detected at the position of the outlined figure at each timing inFIG.18. By verifying at which timing of timing t1, timing t2, timing t3, timing t4, and timing t5the reflected light is detected, the identification number of the detection device16for each position coordinate on the image can be identified.

In the example ofFIG.18, reflected light is detected at each of timing to, timing t1, timing t2, timing t3, timing t4, and timing t5as follows. At timing to, reflected light is detected at (x1, y1), (x2, y2), (x3, y3), (x4, y4), and (x5, y5). At timing t1, reflected light is detected at (x1, y1), (x2, y2), (x3, y3), and (x4, y4). At timing t2, reflected light is detected at (x2, y2), (x3, y3), and (x4, y4). At timing t3, reflected light is detected at (x1, y1), (x2, y2), (x3, y3), and (x4, y4). At timing t4, reflected light is detected at (x3, y3), and (x4, y4). At timing t5, reflected light is detected at (x1, y1), and (x4, y4).

FIG.19illustrates an example (identification information1440) of the identification information stored in the monitoring device10. The identification information1440stores identification numbers set for the plurality of detection devices16and light reception timings relevant to the identification numbers. The monitoring device10identifies the identification number according to the detection pattern of the reflected light detected at the predetermined timing.

FIG.20illustrates an example of the detection information (detection information1430) in which the position of the reflected light detected on the image obtained by imaging the projection target surface180is associated with the identification number. By referring to the detection information1430, it is possible to grasp the positional relationship of the plurality of detection devices16in the monitored space181projected on the projection target surface180. The detection device16with the identification number 21 is located at (x1, y1). The detection device16with the identification number 28 is located at (x2, y2). The detection device16with the identification number 30 is located at (x3, y3). The detection device16with the identification number 15 is located at (x4, y4). The detection device16with the identification number 16 is located at (x5, y5).

The monitoring device10transmits the detection information as illustrated inFIG.20to a management center (not illustrated). For example, an administrator of the management center uses the received detection information to display the position of the monitoring target where the detection device16is installed on the screen in real time or to issue a warning according to the positional relationship between the monitoring targets.

(Operation)

Next, the operation of the monitoring device10and the detection device16included in the management system1will be described with reference to the drawings. Hereinafter, the operation of the monitoring device10and the detection device16will be individually described.

[Monitoring Device]

FIG.21is a flowchart for explaining an example of the operation of the monitoring device10. In the description alongFIG.21, the monitoring device10will be described as main operation.

InFIG.21, first, the monitoring device10sets a pattern for projecting the detection light105as the display part of the spatial light modulator130(step S101).

Next, the monitoring device10controls the light source120to emit laser light (parallel light102) (step S102). As a result, the parallel light102emitted to the display part of the spatial light modulator130is modulated, and the detection light105is projected from the monitoring device10.

When the reflected light is detected (Yes in step S103), the monitoring device10records a detection pattern of the reflected light in a predetermined period after the reflected light is detected (step S104). On the other hand, when the reflected light is not detected (No in step S103), the monitoring device10waits until the reflected light is detected.

After step S104, the monitoring device10identifies the identification number based on the detected detection pattern of the reflected light (step S105).

Then, the monitoring device10outputs the detection information in which the identification number is associated with the detection position of the reflected light (step S106). In step S106, the process according to the flowchart ofFIG.21ends. In a case where the process according to the flowchart ofFIG.21is continued, the process may be set to return to step S101or step S103after step S106.

[Detection Device]

FIG.22is a flowchart for explaining an example of the operation of the detection device16. In the description alongFIG.22, the detection device16will be described as main operation.

When the detection light105is detected (Yes in step S161), the detection device16controls the shutter161to open and close at a timing set in advance based on the identification number of the detection device in a predetermined period from the timing at which the detection light105is detected (step S162). On the other hand, when the detection light is not detected (No in step S161), the detection device16keeps the shutter161open.

After step S162, when a predetermined period has elapsed from the timing at which the detection light105is detected, the detection device16opens the shutter161(step S163).

As described above, the management system of the present example embodiment includes the monitoring device and at least one detection device. The monitoring device projects detection light for detecting a monitoring target. The detection device is installed on the monitoring target. The detection device receives the detection light projected by the monitoring device, and reflects the detection light at a timing set in the detection device in a predetermined period starting from a timing at which the detection light is received. The monitoring device identifies the monitoring target based on the detection pattern of the reflected light of the detection light.

According to the present example embodiment, since the monitoring target can be identified according to the pattern of the reflected light, it is possible to grasp the positional relationship of the monitoring target located in the monitored space and perform safety management.

In one mode of the present example embodiment, the detection device includes a light receiver, a reflector, a shutter, an opening and closing condition storage unit, and an opening and closing control unit. The light receiver receives detection light projected from the monitoring device.

The reflector retroreflects the detection light projected from the monitoring device. The shutter is opened and closed to control the incidence of light on the reflector. The opening and closing condition storage unit stores the opening and closing condition of the shutter according to the identification number set in the detection device. The opening and closing control unit opens and closes the shutter based on the opening and closing condition stored in the opening and closing condition storage unit in a predetermined period starting from the timing at which the light receiver receives the detection light.

In one mode of the present example embodiment, the detection device opens and closes the shutter in the arrangement order of the logical values of the bits when the identification number set in the detection device is expressed in the binary number in a predetermined period starting from the timing at which the detection light is received. The monitoring device identifies the identification numbers of the detection devices at the plurality of positions where the reflected light is detected based on the detection patterns of the reflected light at the plurality of positions where the reflected light is detected.

In one mode of the present example embodiment, the monitoring device identifies the identification numbers of the plurality of detection devices at the positions where the reflected light is detected based on the detection patterns of the reflected light at the plurality of positions where the reflected light is detected, and outputs the detection information including the positional relationship among the plurality of detection devices.

In one mode of the present example embodiment, the monitoring device includes a projector, a projection control unit, a reflected light receiver, and an identification unit. The projector includes a light source that emits light having a wavelength in an infrared region, and a spatial light modulator including a display part irradiated with the light emitted from the light source. The projection control unit controls the spatial light modulator to set a pattern to be displayed on the display part, and controls the light source to set the irradiation timing of the light emitted to the display part. The reflected light receiver receives the reflected light. When the reflected light receiver receives the reflected light, the identification unit identifies the identification number of the detection device at the position where the reflected light is detected based on the detection pattern of the reflected light at the position where the reflected light is detected in a predetermined period starting from the timing at which the reflected light is detected.

Second Example Embodiment

Next, a management system according to a second example embodiment will be described with reference to the drawings. The present example embodiment is different from the first example embodiment in that a monitoring device projects projection light in a visible region in addition to detection light in an infrared region.

(Configuration)

FIG.23is a block diagram illustrating an example of the monitoring device20according to the present example embodiment. The monitoring device20includes a projector21, a projection control unit23, a reflected light receiver24, and an identification unit25. The projection control unit23and the identification unit25constitute a monitoring control unit22. The reflected light receiver24and the identification unit25is similar to the reflected light receiver14and the identification unit15, respectively, of the first example embodiment, and thus, a detailed description thereof will be omitted.

The projector21is a projector including a spatial light modulator. The projector21projects detection light having a wavelength in an infrared region under the control of the projection control unit23. The projector21projects projection light having a wavelength in the visible region under the control of the projection control unit23. The spatial light modulator of the projector21includes a modulation unit that displays a pattern according to the detection light or the projection light to be projected. The light emitted to the modulation unit in a state where the pattern according to the detection light or the projection light is displayed is modulated when reflected by the modulation unit. The light modulated by the modulation unit is projected as detection light or projection light via the projection optical system. For example, the projector21switches and projects the detection light or the projection light under the control from the projection control unit23. For example, the projector21simultaneously projects the detection light and the projection light under the control from the projection control unit23.

The projection control unit23causes the modulation unit of the spatial light modulator of the projector21to display a pattern according to the detection light or the projection light. The projection control unit23controls the emission timing of the light source of the projector21in a state where the pattern according to the detection light or the projection light is displayed on the modulation unit, and causes the light source to irradiate the modulation unit with light. For example, the projection control unit23receives an instruction to switch the projection of the detection light and the projection light from the identification unit25, and switches the projection of the detection light and the projection light according to the received instruction.

When the reflected light is not received by the reflected light receiver24, the projection control unit23causes the projector21to project the detection light in the infrared region. When the reflected light receiver24receives the reflected light, the projection control unit23causes the projector21to continuously project the detection light in the infrared region for a predetermined period from the timing at which the reflected light is received. Then, when the identification number of the detection device is specified after a lapse of a predetermined period from the timing at which the reflected light is received, the projection control unit23causes the projector21to project the projection light in the visible region such that display-information according to the identification number is displayed near the monitoring target to which the identification number is assigned.

<Projector>

FIG.24is a conceptual diagram illustrating an example of a configuration of the projector21. The projector21includes a light source220, a spatial light modulator230, and a projection optical system240. Note thatFIG.24is conceptual, and does not accurately represent the positional relationship between the components, the light irradiation direction, and the like. The projector21is different from the projector11of the first example embodiment in the configuration of the light source. In the following description, the configuration of the light source220will be mainly focused.

The light source220includes an emitter221that emits laser light201having a wavelength in an infrared region, a collimator223that converts the laser light201emitted from the emitter221into parallel light202, and a half mirror224that reflects the parallel light202toward a display part of the spatial light modulator230. The light source220includes an emitter251that emits laser light261having a wavelength in the visible region, a collimator253that converts the laser light261emitted from the emitter251into parallel light262, and a mirror254that reflects the parallel light262toward a display part of the spatial light modulator230.

The emitter221emits the laser light201having a wavelength in the infrared region under the control of the projection control unit23. The laser light201emitted from the emitter221is converted into the parallel light202by the collimator223. The parallel light202is reflected by the half mirror224and emitted from the light source220. The parallel light202emitted from the light source220travels toward the modulation unit of the spatial light modulator230. For example, the emitter221emits laser light201in a 1.0 micrometer band or a 1.5 micrometer band. The wavelength region of the light emitted from the emitter221is not limited to a 1.0 micrometer band or a 1.5 micrometer band. The emitter221may be configured to emit light of a plurality of wavelength regions instead of a single wavelength region.

The emitter251emits the laser light261having a wavelength in the visible region under the control of the projection control unit23. The laser light261emitted from the emitter251is converted into the parallel light262by the collimator253. The parallel light262is reflected by the mirror254, passes through the half mirror224, and is emitted from the light source220. The parallel light262emitted from the light source220travels toward the modulation unit of the spatial light modulator230. For example, the emitter221emits laser light261having a wavelength included in a wavelength region of 380 to 750 nanometers. The emitter221may be configured to emit laser light261of a plurality of wavelength regions instead of laser light261of a single wavelength region.

The parallel light202incident on the modulation unit of the spatial light modulator230is modulated into the modulated light203when reflected by the modulation unit of the spatial light modulator230. The modulated light203is projected as the detection light205via the projection optical system240. The parallel light262incident on the modulation unit of the spatial light modulator230is modulated into the modulated light263when reflected by the modulation unit of the spatial light modulator230. The modulated light263is projected as the projection light265via the projection optical system240. In actual, materials suitable for the Fourier transform lens246and the projection lens248included in the projection optical system240are different between the modulated light203in the infrared region and the modulated light263in the visible region. Therefore, it is preferable that the modulated light203having the wavelength in the infrared region and the modulated light263having the wavelength in the visible region are projected via different projection optical systems240suitable for the light.

FIG.25illustrates an example in which the display-information formed by the projection light265projected from the monitoring device20is displayed near the detection device26of the identification number 21. In the example ofFIG.25, the forklift in which the detection device26of the identification number 28 is installed approaches from behind the worker wearing the helmet in which the detection device26of the identification number 21 is installed. For example, a warning range according to the distance between the detection device26with the identification number 21 and the detection device26with the identification number 28 is set between these detection devices26. When the distance between the detection device26with the identification number 21 and the detection device26with the identification number 28 falls within the warning range, display-information indicating a warning is displayed near the detection device26with the identification number 21. As a result, the worker wearing the helmet in which the detection device26of the identification number 21 is installed can sense danger by the display-information displayed in the vicinity.

FIG.26illustrates an example (identification information2440) of the identification information stored in the monitoring device20. The identification information2440stores identification numbers set for the plurality of detection devices26and light reception timings relevant to the identification numbers. The identification information2440also stores a warning range associated with the identification number of each of the plurality of detection devices26. For example, the warning range is set according to the type of the monitoring target in which the detection device26is installed. The monitoring device20identifies the identification number according to the detection pattern of the reflected light detected at the predetermined timing.

FIG.27illustrates an example of the detection information (detection information2430) in which the position of the reflected light detected is associated with the identification number. The detection information2430ofFIG.27includes a positional relationship of the detected identification numbers and a warning flag based on a warning range associated with the identification numbers.

The positional relationship among the plurality of detection devices26can be grasped with reference to the detection information2430. The detection device16with the identification number 21 is located at (x1, y1). The detection device16with the identification number 28 is located at (x2, y2). The detection device16with the identification number 30 is located at (x3, y3). The detection device16with the identification number 15 is located at (x4, y4). The detection device16with the identification number 16 is located at (x5, y5). Presence or absence of the warning according to the positional relationship among the plurality of detection devices26can be grasped with reference to the detection information2430. The monitoring device20displays the display-information near at least one of the detection devices26in which the warning ranges overlap based on the identified identification number. For example, the monitoring device20displays display-information indicating a warning near the detection device26with the identification number in which the warning flag is 1.

(Operation)

Next, the operation of the monitoring device20will be described with reference to the drawings.FIG.28is a flowchart for explaining the operation of the monitoring device20. In the description alongFIG.28, the monitoring device20will be described as main operation.

InFIG.28, first, the monitoring device20sets a pattern for projecting the detection light105as the display part of the spatial light modulator230(step S201).

Next, the monitoring device20controls the light source220to emit laser light (parallel light202) having a wavelength in an infrared region (step S202). As a result, the parallel light202emitted to the display part of the spatial light modulator230is modulated, and the detection light205is projected from the monitoring device20.

When the reflected light is detected (Yes in step S203), the monitoring device20records a detection pattern of the reflected light in a predetermined period after the reflected light is detected (step S204). On the other hand, when the reflected light is not detected (No in step S203), the monitoring device20waits until the reflected light is detected.

After step S204, the monitoring device20identifies the identification number based on the detected detection pattern of the reflected light (step S205).

Next, the monitoring device20outputs the detection information in which the identification number is associated with the detection position of the reflected light (step S206). When the detection information is not output, step S206may be omitted.

When the warning flag is set on the identified identification number (Yes in step S207), the monitoring device20projects projection light for displaying display-information according to a warning content toward the periphery of the detection device26as a warning target (step S208). In a case of projecting the projection light, the monitoring device20sets a pattern for projecting the projection light according to the warning content in the display part of the spatial light modulator230, and controls the light source220to emit the laser light261in the visible region from the emitter251. In step S208, the process according to the flowchart ofFIG.28ends. In a case where the process according to the flowchart ofFIG.28is continued, the process may be set to return to step S201or step S203after step S208.

On the other hand, when the warning flag is not set for the identified identification number (No in step S207), the process of step S208is not performed, and the process according to the flowchart ofFIG.28ends. In a case where the process according to the flowchart ofFIG.28is continued, the process may be set to return to step S201or step S203.

As described above, the monitoring device according to the present example embodiment includes a projector, a projection control unit, a reflected light receiver, and an identification unit. The projector includes a light source that emits light having a wavelength in an infrared region and a visible region, and a spatial light modulator including a display part irradiated with the light emitted from the light source. When projecting the detection light, the projection control unit controls the spatial light modulator to set a pattern to be displayed on the display part, and controls the light source to set the irradiation timing of the light having a wavelength in an infrared region emitted to the display part. The reflected light receiver receives the reflected light. When the reflected light receiver receives the reflected light, the identification unit identifies the identification number of the detection device at the position where the reflected light is detected based on the detection pattern of the reflected light at the position where the reflected light is detected in a predetermined period starting from the timing at which the reflected light is detected.

The identification unit of one mode of the present example embodiment issues, in response to the identification of the identification number of the detection device, an instruction to the projection control unit to display display-information according to the identified identification number of the detection device near the detection device. The projection control unit controls the spatial light modulator in order to set a pattern for projecting the projection light for displaying display-information is displayed near the detection device on the display part according to the instruction of the identification unit. The projection control unit controls the light source in order to set the irradiation timing of the light having the wavelength in the visible region that is emitted to the display part in accordance with the control of the spatial light modulator.

The identification unit of one mode of the present example embodiment issues, in response to the identification of the identification numbers of a plurality of detection device, an instruction to the projection control unit to display display-information including notification contents according to the positional relationship of the identified detection devices near the detection devices. The projection control unit controls the spatial light modulator in order to set a pattern for projecting the projection light for displaying display-information is displayed near the detection device on the display part according to the instruction of the identification unit. The projection control unit controls the light source in order to set the irradiation timing of the light having the wavelength in the visible region that is emitted to the display part in accordance with the control of the spatial light modulator.

When the identification unit of one mode of the present example embodiment identifies the identification numbers of a plurality of detection device, the identification unit issues an instruction to the projection control unit to display display-information including a warning according to a space between at least two detection devices near the detection devices. The projection control unit controls the spatial light modulator in order to set a pattern for projecting the projection light for displaying display-information including a warning is displayed near the detection device on the display part according to the instruction of the identification unit. The projection control unit controls the light source in order to set the irradiation timing of the light having the wavelength in the visible region that is emitted to the display part in accordance with the control of the spatial light modulator.

Third Example Embodiment

Next, a management system according to a third example embodiment will be described with reference to the drawings. The present example embodiment is different from the first and second example embodiments in that communication light is projected onto a detection device in addition to detection light for detecting the detection device. In addition, the present example embodiment is different from the first and second example embodiments in including a notification device that operates according to communication light when the detection device receives the communication light.

(Configuration)

FIG.29is a block diagram illustrating an example of the monitoring device30according to the present example embodiment. The monitoring device30includes a projector31, a projection control unit33, a reflected light receiver34, and an identification unit35. The projection control unit33and the identification unit35constitute a monitoring control unit32. The reflected light receiver34and the identification unit35is similar to the reflected light receiver14and the identification unit15, respectively, of the first example embodiment, and thus, a detailed description thereof will be omitted.

The projector31is a projector including a spatial light modulator. The projector31projects detection light having a wavelength in an infrared region at a first output under the control of the projection control unit33. The projector31projects communication light having a wavelength in an infrared region at a second output under the control of the projection control unit33. The first output is set to be higher than the second output. The spatial light modulator of the projector31includes a modulation unit that displays a pattern according to the detection light and the communication light to be projected. The light emitted to the modulation unit in a state where the pattern according to the detection light and the communication light is displayed is modulated when reflected by the modulation unit. The light modulated by the modulation unit is projected as detection light and communication light via the projection optical system. For example, the projector31switches and projects the detection light or the communication light under the control from the projection control unit33.

The projection control unit33causes the modulation unit of the spatial light modulator of the projector31to display a pattern according to the detection light and the communication light. The projection control unit33controls the emission timing of the light source of the projector31in a state where the pattern according to the detection light and the communication light is displayed on the modulation unit, and causes the light source to irradiate the modulation unit with light. For example, the projection control unit33receives an instruction to switch the projection of the detection light and the communication light from the identification unit35, and switches the projection of the detection light and the projection light according to the received instruction.

When the reflected light is not received by the reflected light receiver34, the projection control unit33causes the projector31to project the detection light in the infrared region. When the reflected light receiver34receives the reflected light, the projection control unit33causes the projector31to project the detection light in the infrared region for a predetermined period from the timing at which the reflected light is received. Then, when a predetermined period has elapsed from the timing at which the reflected light is received and the identification number and position of the detection device are specified, the projection control unit33causes the projector31to project communication light including communication information according to the specified identification number.

<Projector>

FIG.30is a conceptual diagram illustrating an example of a configuration of the projector31. The projector31includes a first light source320, a second light source350, a polarization prism324, a liquid crystal element325, a spatial light modulator330, and a projection optical system340. Note thatFIG.30is conceptual, and does not accurately represent the positional relationship between the components, the light irradiation direction, and the like. The projector31is different from the projector11of the first example embodiment in the configuration of the light source. In the following description, the configuration of the light source (first light source320and second light source350) will be mainly focused.

The first light source320includes an emitter321that emits laser light301having a wavelength in an infrared region, and a collimator323that converts the laser light301emitted from the emitter321into parallel light3011. The emitter321emits the laser light301having a wavelength in the infrared region under the control of the projection control unit33. The laser light301emitted from the emitter321is converted into the parallel light3011by the collimator323, and emitted from the first light source320. The parallel light3011emitted from the first light source320is converted into polarized light302by the polarization prism324, then converted into modulated light303by the modulation unit of the spatial light modulator330, and projected as detection light305.

For example, the emitter321emits laser light301in a 1.0 micrometer band. The wavelength region of the light emitted from the emitter321is not limited to a 1.0 micrometer band. The emitter321may be configured to emit light of a plurality of wavelength regions instead of a single wavelength region. The emitter321may emit light in the same wavelength region as that of the emitter351, or may emit light in a wavelength region different from that of the emitter351. As the emitter321, an emitter capable of setting a higher output than the emitter351is used.

The second light source350includes an emitter351that emits laser light391having a wavelength in an infrared region, and a collimator353that converts the laser light391emitted from the emitter351into parallel light3911. The emitter351emits the laser light391having a wavelength in the infrared region under the control of the projection control unit33. The laser light391emitted from the emitter351is converted into the parallel light3911by the collimator353, and emitted from the second light source350.

The laser light391emitted from the emitter351is directly modulated under the control of the projection control unit33. For example, the projection control unit33modulates the laser light391emitted from the emitter351by operating the emitter351to generate a pulse in which the laser light having a second luminance higher than a first luminance is added to the laser light having the first luminance. For example, the emitter351emits laser light261in a 1.5 micrometer band. The wavelength region of the light emitted from the emitter351is not limited to a 1.5 micrometer band. The emitter351may be configured to emit light of a plurality of wavelength regions instead of a single wavelength region.

The polarization prism324is installed on a path of parallel light3011emitted from first light source320and parallel light3911emitted from second light source350. The polarization prism324is irradiated with the parallel light3011emitted from first light source320and the parallel light3911emitted from second light source350. The polarization prism324converts each of the parallel light3011and the parallel light3911respectively emitted from the first light source320and the second light source350into completely polarized light (polarized light302, polarized light392). The polarized light302and the polarized light392converted into the completely polarized light by the polarization prism324travel toward the liquid crystal element325.

The liquid crystal element325is installed between the polarization prism324and the spatial light modulator330. The liquid crystal element325is irradiated with the polarized light302and the polarized light392converted into the completely polarized light by the polarization prism324. The liquid crystal element325rotates the polarization planes of the emitted polarized light302and polarized light392. The polarized light302and the polarized light392with the rotated polarization plane travel toward the display part of the spatial light modulator330.

A pattern for projecting the detection light305is set in the modulation unit of the spatial light modulator330. The polarized light302incident on the modulation unit of the spatial light modulator330in which the pattern for projecting the detection light305is set is modulated into the modulated light303when reflected by the modulation unit of the spatial light modulator330. The modulated light303is projected as the detection light305via the projection optical system340.

A pattern for determining the projection direction of the communication light395is set in the modulation unit of the spatial light modulator330. The polarized light392incident on the modulation unit of the spatial light modulator330in which the pattern for determining the projection direction of the communication light395is set is reflected by the modulation unit of the spatial light modulator330. Since the polarized light392has already been modulated, it is not modulated by the modulation unit of the spatial light modulator330. The reflected light (modulated light393) reflected by the modulation unit of the spatial light modulator330has a component similar to that of the polarized light392. The modulated light393is projected as the communication light395via the projection optical system340.

<Projection Control Unit>

FIG.31is a block diagram illustrating an example of a configuration of the projection control unit33. The projection control unit33includes a projection condition storage unit331, a projection condition setting unit332, a modulator control unit333, a light source control unit334, and a light source modulation unit335. In a case where the light source control unit334has a modulation function, the light source control unit334and the light source modulation unit335may have a single configuration.

The projection condition storage unit331stores a pattern according to the detection light305and a pattern according to the communication light395. In a case where the spatial light modulator330of the projector31is of a phase modulation type, the projection condition storage unit331stores a phase distribution according to the detection light305and the communication light395. The projection condition storage unit331stores the projection condition including a light source control condition for controlling the first light source320, a light source modulation condition for controlling the second light source350, and a modulation element control condition for controlling the spatial light modulator330.

In a case of projecting the detection light305, the projection condition setting unit332sets a projection condition for projecting the detection light305. That is, the projection condition setting unit332sets, in the modulator control unit333, a modulation element control condition for setting a pattern according to the detection light305in the modulation unit of the spatial light modulator330. The projection condition setting unit332sets, in the light source control unit334, a light source control condition for emitting the laser light301from the first light source320. The projection condition setting unit332matches the timing at which the modulation element control condition is set in the modulator control unit333with the timing at which the light source control condition is set in the light source control unit334for emitting the detection light305. As a result, the display part of the spatial light modulator330in a state where the pattern according to the detection light305is displayed is irradiated with the polarized light302based on the laser light301emitted from the first light source320.

In a case of projecting the communication light395, the projection condition setting unit332sets a projection condition for projecting the communication light395. That is, the projection condition setting unit332sets, in the modulator control unit333, a modulation element control condition for setting a pattern according to the communication light395in the modulation unit of the spatial light modulator330. The projection condition setting unit332sets a light source modulation condition for adding a signal to the communication light395to the second light source350. The projection condition setting unit332matches the timing at which the modulation element control condition is set in the modulator control unit333with the timing at which the light source modulation condition is set in the light source modulation unit335for emitting the communication light395. As a result, the display part of the spatial light modulator330in a state where the pattern according to the projection direction of the communication light395is displayed is irradiated with the polarized light392based on the laser light391emitted from the second light source350.

In a case of projecting the detection light305, the modulator control unit333receives the pattern according to the detection light305and the modulation element control condition from the projection condition setting unit332. The modulator control unit333drives a driver (not illustrated) that changes the pattern set in the modulation unit of the spatial light modulator330according to the modulation element control condition received from the projection condition setting unit332. As a result, a pattern according to the detection light305is set in the modulation unit of the spatial light modulator330.

In a case of projecting the communication light395, the modulator control unit333receives the pattern according to the communication light395and the modulation element control condition from the projection condition setting unit332. The modulator control unit333drives a driver (not illustrated) that changes the pattern set in the modulation unit of the spatial light modulator330according to the modulation element control condition received from the projection condition setting unit332. As a result, a pattern according to the communication light395is set in the modulation unit of the spatial light modulator330. In a case of projecting the communication light395, not a pattern for modulating the polarized light392but a pattern for setting the projection direction of the communication light395is set in the modulation unit of the spatial light modulator330.

The light source control unit334is connected to the projection condition setting unit332and the first light source320. The light source control unit334drives a driving unit (not illustrated) of the emitter321according to the light source control condition received from the projection condition setting unit332. As a result, the laser light301is emitted from the emitter321. Then, the modulation unit of the spatial light modulator330is irradiated with the polarized light302caused by the laser light301in accordance with the timing at which the pattern is set in the modulation unit of the spatial light modulator330, and the detection light305relevant to the pattern displayed on the modulation unit of the spatial light modulator330is projected.

The light source modulation unit335is connected to the projection condition setting unit332and the second light source350. The light source modulation unit335controls the current of the emitter351included in the second light source350according to the light source modulation condition received from the projection condition setting unit332, and modulates the light intensity of the laser light391emitted from the second light source350. The light source control unit334modulates the pulse of the laser light391emitted from the second light source350according to the pattern of the signal to be added to the communication light395. A pulsed laser light391according to a pattern of a signal to be added to the communication light395is emitted from the emitter351. As a result, the modulation unit of the spatial light modulator330is irradiated with the polarized light392caused by the laser light391in accordance with the timing at which the pattern is set in the modulation unit of the spatial light modulator330, and the communication light395is projected in the projection direction based on the pattern displayed on the modulation unit of the spatial light modulator330.

[Detection Device]

FIG.32is a conceptual diagram illustrating an example of a configuration of a detection device36according to the present example embodiment. The detection device36includes a shutter361, a reflector362, a receiver363, an opening and closing control unit364, an opening and closing condition storage unit365, and a notification control unit366. The opening and closing control unit364, the opening and closing condition storage unit365, and the notification control unit366constitute a detection control unit380. The notification control unit366is connected to a notifier370. The notifier370may be included in the configuration of the detection device36. Since the shutter361, the reflector362, the receiver363, the opening and closing control unit364, and the opening and closing condition storage unit365are similar to those of the first example embodiment, detailed description thereof will be omitted. In the following description, differences from the first and second example embodiments will be focused on.

The notifier370is a device that notifies reception of the detection light305or the communication light395. The notifier370generates light, sound, vibration, and the like under the control of the notification control unit366. For example, the notifier370is achieved by a device that emits light, such as a light emitting diode or a light bulb. For example, the notifier370is achieved by a device that emits sound, such as a headphone, an earphone, or a speaker. For example, the notifier370is achieved by a device that emits vibration, such as a vibration generator.

The receiver363is a photodetector that receives the detection light305and the communication light395. When receiving the detection light305and the communication light395, the receiver363converts the received detection light305and communication light395into an electric signal. The receiver363outputs the converted electric signal to the opening and closing control unit164. The detection light305and the communication light395may be received by different light receivers363.

The notification control unit366receives an electric signal based on the detection light305or the communication light395from the receiver363. The notification control unit366controls the notifier370in accordance with the received electric signal. For example, upon receiving an electric signal based on the detection light305, the notification control unit366controls the notifier370to generate light, sound, or vibration.

FIG.33is a conceptual diagram illustrating an example of a helmet360that achieves the detection device36. The helmet360includes a shutter (not illustrated), a reflector362-1, a receiver363-1, and a detection control unit380-1. InFIG.33, a shutter is not illustrated in order to make the reflector362-1easily visible. The helmet360includes a first notifier371and a second notification device372. For example, the first notifier371is installed on the back side or the side of the brim of the helmet360and emits light under the control of the detection control unit380-1. For example, the second notifier372is installed on the side of the helmet360and the second notifier372emits sound under the control of the detection control unit380-1. The worker wearing the helmet360can recognize the notification from the monitoring device30by the light emission of the first notifier371and the sound from the second notifier372.

The shutter is installed to face the reflecting surface of the reflector362-1. The shutter is opened and closed under the control of the detection control unit380-1. When the shutter is opened, the detection light305is incident on the reflector362-1. When the shutter is closed, the detection light305is not incident on the reflector362-1. Opening/closing control of the shutter is similar to that of the shutter361of the detection device36. For example, if the shutter is achieved by a flexible liquid crystal element, it is easy to form the shutter according to the shape of the helmet360.

The reflector362-1has a reflecting surface that reflects the detection light and the communication light. The reflector362-1is installed such that the reflecting surface faces the shutter. The reflector362-1reflects the detection light and the communication light incident on the reflecting surface toward the monitoring device30. The reflector362-1has the same configuration as the reflector162of the first example embodiment.

The receiver363-1is a photodetector that receives the detection light305and the communication light395. When receiving the detection light305or the communication light395, the receiver363-1converts the received detection light305or communication light395into an electric signal. The receiver363outputs the converted electric signal to the detection control unit380-1.

For example, the receiver363-1can be achieved by a combination of an optical fiber formed in a linear shape or a plate shape and a light detection element installed with a light receiving surface facing an emission end of the optical fiber. For example, the receiver363-1receives the detection light305and the communication light395from the side surface of the optical fiber, totally reflects the received light inside the optical fiber, and guides the light toward a light detection element installed at one end portion of the optical fiber. The receiver363-1converts light received by the light detection element installed at one end portion of the optical fiber into an electric signal and outputs the electric signal to the detection control unit380-1.

The detection control unit380-1receives an electric signal from the receiver363-1. When receiving the electric signal based on the detection light, the detection control unit380-1performs the opening and closing control of the shutter based on the opening and closing condition set in the detection device. When receiving the electric signal based on the communication light, the detection control unit380-1controls at least one of the first notifier371and the second notifier372to cause the first notifier371to emit light or cause the second notifier372to generate sound. For example, the worker wearing the helmet360recognizes the notification based on the communication light395by visually recognizing that the first notifier371emits light or listening to the sound from the second notifier372.

For example, when the worker wearing the helmet360is in danger, the detection control unit380-1transmits the communication light395for notifying that danger is imminent to the helmet360. The worker wearing the helmet360can sense that danger is imminent according to the light emission of the first notifier371and the sound from the second notifier372.

(Operation)

Next, the operation of the monitoring device30and the detection device36included in the management system of the present example embodiment will be described with reference to the drawings. Hereinafter, the operation of the monitoring device30and the detection device36will be individually described.

[Monitoring Device]

InFIG.34, first, the monitoring device30sets a pattern for projecting the detection light as the display part of the spatial light modulator330(step S301).

Next, the monitoring device30controls the first light source320to emit laser light (polarized light302) having a wavelength in an infrared region (step S302). As a result, the polarized light302emitted to the display part of the spatial light modulator330on which the display is performed is modulated, and the detection light305is projected from the monitoring device30.

When the reflected light is detected (Yes in step S303), the monitoring device30records a detection pattern of the reflected light in a predetermined period after the reflected light is detected (step S304). On the other hand, when the reflected light is not detected (No in step S303), the monitoring device30waits until the reflected light is detected.

After step S304, the monitoring device30identifies the identification number based on the detected detection pattern of the reflected light (step S305).

Next, the monitoring device30outputs the detection information in which the identification number is associated with the detection position of the reflected light (step S306). When the detection information is not output, step S306may be omitted.

When there is a notification to any of the identified detection devices36(Yes in step S307), the monitoring device30projects communication light including the notification to the detection device36as the notification target (step S308). In a case of projecting the communication light, the monitoring device30sets a pattern for projecting the communication light on the display part of the spatial light modulator330, and controls the second light source350to emit the laser light391in the infrared region from the emitter351. In step S308, the process according to the flowchart ofFIG.34ends. In a case where the process according to the flowchart ofFIG.34is continued, the process may be set to return to step S301or step S303after step S308.

On the other hand, when there is no notification (No in step S307), the process of step S308is not performed, and the process according to the flowchart ofFIG.34ends. In a case where the process according to the flowchart ofFIG.34is continued, the process may be set to return to step S301or step S303.

[Detection Device]

FIG.35is a flowchart for explaining an example of the operation of the detection device36. In the description alongFIG.35, the detection device36will be described as main operation.

When the detection light305is detected (Yes in step S361), the detection device36controls the shutter361to open and close at a timing set in advance based on the identification number in a predetermined period from the timing at which the detection light305is detected (step S362). On the other hand, when the detection light is not detected (No in step S361), the detection device36keeps the shutter361open.

After step S362, when a predetermined period has elapsed from the timing at which the detection light305is detected, the detection device36opens the shutter361(step S363).

When the communication light395is received (Yes in step S364), the detection device36operates the notifier370(step S365). In step S365, the process according to the flowchart ofFIG.35ends. In a case where the process according to the flowchart ofFIG.35is continued, the process may be set to return to step S361after step S365.

On the other hand, when the communication light395is not received (No in step S364), the process according to the flowchart ofFIG.35ends. In a case where the process according to the flowchart ofFIG.35is continued, the process may be set to return to step S361.

As described above, the monitoring device according to the present example embodiment includes a projector, a projection control unit, a reflected light receiver, and an identification unit. The detection device of the present example embodiment includes a notifier that performs notification according to notification contents of communication light.

The projector includes a first light source that emits light having a wavelength in an infrared region at a first output, a second light source that emits light having a wavelength in an infrared region at a second output lower than the first output, and a spatial light modulator including a display part irradiated with the light emitted from the first light source and the second light source. When projecting the detection light, the projection control unit controls the spatial light modulator to set a pattern to be displayed on the display part, and controls the first light source to set the irradiation timing of the light emitted to the display part. The reflected light receiver receives the reflected light. When the reflected light receiver receives the reflected light, the identification unit identifies the identification number of the detection device at the position where the reflected light is detected based on the detection pattern of the reflected light at the position where the reflected light is detected in a predetermined period starting from the timing at which the reflected light is detected.

In one mode of the present example embodiment, when the identification unit identifies the identification number of the detection device, the identification unit issues an instruction to the projection control unit to project communication light according to the identified identification number of the detection device. In response to an instruction from the identification unit, the projection control unit controls the spatial light modulator to set a pattern for projecting the communication light toward the detection device in the display part, and controls the second light source to set the irradiation timing of the light that is emitted to the display part.

In one mode of the present example embodiment, when the identification unit identifies the identification numbers of a plurality of detection device, the identification unit issues an instruction to the projection control unit to project communication light including notification contents according to the positional relationship of the identified detection devices to the detection devices. In response to an instruction from the identification unit, the projection control unit controls the spatial light modulator to set a pattern for projecting the communication light toward the detection device in the display part, and controls the second light source to set the irradiation timing of the light that is emitted to the display part.

In the present example embodiment, a notifier is provided in the detection device to directly notify the worker wearing the detection device. Therefore, according to the present example embodiment, it is possible to more reliably notify the worker wearing the detection device according to the surrounding situation.

Application Example

Next, an application example in which the management system of each example embodiment is applied to management of monitoring targets such as workers and facilities will be described with some examples. The following application example is an example, and does not limit the management system according to each example embodiment.

Application Example 1

FIG.36is a conceptual diagram for explaining Application Example 1. In Application Example 1, the monitoring device50also transmits communication light to a management center500managed by an administrator of a factory.

In the example ofFIG.36, detection devices56with the identification numbers 15, 16, 21, 28, and 30 are located in a monitored space581monitored by the monitoring device50. The detection device56with the identification number 15 is installed in an upper part of an operating room of a crane. The detection device56with the identification number 16 is installed in a hook portion of the crane. The detection devices56with the identification numbers 21 and 30 are installed on the top of a helmet of a worker. The detection device56with the identification number 28 is installed in an upper part of a cab of a forklift.

FIG.37illustrates an example in which an image520indicating the positional relationship among the detection devices56with the identification numbers 15, 16, 21, 28, and 30 is displayed on the display device510installed in the management center500. In the image520, the position where the reflected light is detected is filled in black. InFIG.37, the coordinates of the position where the reflected light is detected and the identification number of the detection device56located at the position coordinates are also written.

According to the present application example, the administrator who manages the factory in the management center500can grasp the positional relationship of the plurality of detection devices56located in the monitored space581by referring to the image520based on the communication light transmitted from the monitoring device50.

Application Example 2

FIG.38is a conceptual diagram for explaining Application Example 2. Application Example 2 is different from Application Example 1 in that a monitoring device50-1includes a camera. In Application Example 2, imaging is performed by a camera to detect a shape and a position from the ground of an object suspended by a crane.

In the example ofFIG.38, detection devices56with the identification numbers 15, 16, and 30 are located in a monitored space581monitored by the monitoring device50-1. For example, the monitoring device50-1images a material suspended by a hook on which the detection device56with the identification number 16 is installed by a camera. The monitoring device50-1analyzes image data generated by imaging and updates identification information.

FIG.39illustrates an example (identification information5440) of the identification information stored in the monitoring device50-1. The identification information5440stores identification numbers set for the plurality of detection devices26and light reception timings relevant to the identification numbers. The identification information5440also stores a warning range associated with the identification number of each of the plurality of detection devices56. The warning range stored in the identification information5440includes an initial value and a correction value.

For example, the initial value of the warning range is set according to the size of the monitoring target in which the detection device56is installed. For example, the correction value of the warning range is set according to the analysis result of the image captured by the monitoring device50-1. In the example ofFIG.39, the warning range of the detection device56with the identification number 16 changes depending on the size of the material suspended by the hook. For example, the monitoring device50-1detects the detection device56to which the warning is to be sent based on the warning range obtained by adding the correction value to the initial value.

In the present application example, the warning range is updated according to the substantial size of the monitoring target. Therefore, according to the present application example, it is possible to more accurately grasp the substantial positional relationship of the monitoring target.

Application Example 3

FIG.40is a conceptual diagram for explaining Application Example 3. Application Example 3 is different from Application Example 1 in that a notification according to the positional relationship of the monitoring target is notified to the detection device.

In the example ofFIG.40, detection devices56with the identification numbers 21 and 28 are located in a monitored space581monitored by the monitoring device50. The monitoring device50transmits the communication light including the notification according to the positional relationship to the detection devices56with the identification numbers 21 and 28.

The monitoring device50transmits communication light for notifying the detection device56with the identification number 21 that a forklift is approaching. The detection device56with the identification number 21 emits a voice notifying that “forklift is approaching”. The worker wearing the detection device56with the identification number 21 recognizes that a forklift is approaching based on a voice “forklift is approaching” from the detection device56.

The monitoring device50transmits communication light for notifying the detection device56with the identification number 28 of deceleration. The detection device56with the identification number 28 emits a voice “please decelerate”. A worker who drives a forklift in which the detection device56with the identification number 28 is mounted recognizes that it is better to decelerate based on a voice “please decelerate” from the detection device56.

According to the present application example, each detection device is notified of a notification according to a situation such as a size, a state, and a positional relationship of a monitoring target. Therefore, according to the present application example, an appropriate notification can be sent to the monitoring target according to the situation of the monitoring target.

Application Example 4

FIG.41is a conceptual diagram for explaining Application Example 4. Application Example 4 is different from Application Example 1 in that a plurality of monitoring devices50cooperate each other.

In the present application example, monitoring devices50-1and50-2that communicate with each other by communication light are used. The monitoring device50-1also communicates with the management center500by communication light. The detection devices56with the identification numbers 21, 28, and 30 are located in a monitored space581monitored by the monitoring device50-1. The detection device56with the identification number 21 is shielded by an obstacle550and is not detected by the monitoring device50-1. However, the detection device56with the identification number 21 is located in the monitored space582monitored by the monitoring device50-2. Therefore, when the monitoring device50-1and the monitoring device50-2cooperate with each other, all detection devices56located in the monitored space581and the monitored space582can be identified.

According to the present application example, by cooperation of a plurality of monitoring devices, it is possible to manage a detection device that is located in a monitored space of any of the monitoring devices but cannot be directly detected from the monitoring device.

(Hardware)

Here, a hardware configuration for executing processing of the control system (the monitoring control unit12, the detection control unit380, and the like) according to each example embodiment will be described using an information processing apparatus90ofFIG.42as an example. The information processing apparatus90inFIG.42is a configuration example for performing processing of the control system of each example embodiment, and does not limit the scope of the present invention.

As illustrated inFIG.42, the information processing apparatus90includes a processor91, a main storage device92, an auxiliary storage device93, an input and output interface95, and a communication interface96. InFIG.42, the interface is abbreviated as I/F. The processor91, the main storage device92, the auxiliary storage device93, the input and output interface95, and the communication interface96are data-communicably connected to each other via a bus98. The processor91, the main storage device92, the auxiliary storage device93, and the input and output interface95are connected to a network such as the Internet or an intranet via the communication interface96.

The processor91develops the program stored in the auxiliary storage device93or the like in the main storage device92and performs the developed program. In the present example embodiment, it is sufficient that a software program installed in the information processing apparatus90is used. The processor91performs processing by the control system according to the present example embodiment.

The main storage device92has a region in which a program is developed. The main storage device92may be a volatile memory such as a dynamic random access memory (DRAM). A nonvolatile memory such as a magnetoresistive random access memory (MRAM) may be configured and added as the main storage device92.

The auxiliary storage device93stores various data. The auxiliary storage device93includes a local disk such as a hard disk or a flash memory. Various data may be stored in the main storage device92, and the auxiliary storage device93may be omitted.

The input and output interface95is an interface for connecting the information processing apparatus90and a peripheral device. The communication interface96is an interface for connecting to an external system or device through a network such as the Internet or an intranet based on a standard or a specification. The input and output interface95and the communication interface96may be shared as an interface connected to an external device.

An input device such as a keyboard, a mouse, or a touch panel may be connected to the information processing apparatus90as necessary. These input devices are used to input information and settings. When a touch panel is used as an input device, it is sufficient that the display screen of the display device serves as an interface of the input device. It is sufficient that data communication between the processor91and the input device is mediated by the input and output interface95.

The information processing apparatus90may be provided with a display device for displaying information. When a display device is provided, the information processing apparatus90preferably includes a display control device (not illustrated) for controlling display of the display device. The display device may be connected to the information processing apparatus90via the input and output interface95.

The above is an example of a hardware configuration for enabling processing by the control system according to each example embodiment. The hardware configuration ofFIG.42is an example of a hardware configuration for performing processing by the control system according to each example embodiment, and does not limit the scope of the present invention. A program for causing a computer to execute processing by the control system according to each example embodiment is also included in the scope of the present invention. A recording medium in which a program according to each example embodiment is recorded is also included in the scope of the present invention. The recording medium can be achieved by, for example, an optical recording medium such as a compact disc (CD) or a digital versatile disc (DVD). The recording medium may be achieved by a semiconductor recording medium such as a universal serial bus (USB) memory or a secure digital (SD) card, a magnetic recording medium such as a flexible disk, or another recording medium.

The components of the control system of each example embodiment can be arbitrarily combined. The components of the control system of each example embodiment may be achieved by software or may be achieved by a circuit.

While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims.

This application is based upon and claims the benefit of priority from Japanese patent application No. 2020-039649 filed on Mar. 9, 2020, the disclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

1management system10,20,30,50monitoring device11,21,31projector12,22,32monitoring control unit13,23,33projection control unit14,24,34reflected light receiver15,25,35identification unit16,26,36,56detection device120,220light source121,221,251,321,351emitter123,223,253,323,353collimator130,230,330spatial light modulator131,331projection condition storage unit132,332projection condition setting unit133,333modulator control unit134,334light source control unit140,240,340projection optical system141filter142lens143two-dimensional sensor144converter145image processing unit146,246,346Fourier transform lens147,247,347aperture148,248,348projection lens151reflected light detection unit152imaging control unit153identification information identification unit154identification information storage unit161,361shutter162,362reflector163,363receiver164,364opening and closing control unit165,365opening and closing condition storage unit190retroreflector191substrate192spherical bead193focus layer194reflection layer224half mirror254mirror320first light source324polarization prism325liquid crystal element335light source modulation unit350second light source360helmet366notification control unit370notifier371first notifier372second notifier380detection control unit500management center510display device