Risk assessment system and lighting device

Abstract

To provide a risk assessment system and a lighting device configured to enable high-accuracy risk assessment.SOLUTION: A risk assessment system includes a lighting device and an assessment device. The lighting device includes an imaging unit which can image an illumination space. The assessment device detects a state of a target related to occurrence of a hazardous event in the illumination space based on an image captured by the imaging unit, and assesses the risk of the hazardous event in the illumination space based on the detected state of the target.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Embodiments of the present invention relate to a risk assessment system and a lighting device. [Background technology]

[0002] Conventionally, there has been known a technology relating to risk assessment that evaluates the risk of accidents that may occur during work in order to safely proceed with work at work sites such as factories (see, for example, Patent Document 1). For example, Patent Document 1 discloses a technology that performs risk assessment by inputting the equipment to be used, the name of the work, the work procedure, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7369885 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional techniques have room for further improvement in terms of performing risk assessment with higher accuracy.

[0005] The problem to be solved by the present invention is to provide a risk assessment system and a lighting device that can perform risk assessment with high accuracy. [Means for solving the problem]

[0006] A risk assessment system according to an embodiment includes a lighting device and an assessment device. The lighting device includes an imaging unit capable of capturing an image of an illumination space. The assessment device detects the state of an object related to the occurrence of a hazardous event in the illumination space based on the image captured by the imaging unit, and assesses the risk of the hazardous event in the illumination space based on the detected state of the object. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a risk assessment system according to an embodiment. [Figure 2] FIG. 2 is a block diagram illustrating an example of the configuration of the lighting device according to the embodiment. [Figure 3] FIG. 3 is a block diagram illustrating an example of the configuration of an evaluation device according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of evaluation item information. [Figure 5] FIG. 5 is a diagram illustrating an example of report information. [Figure 6] FIG. 6 is a diagram illustrating an example of the severity calculation table. [Figure 7] FIG. 7 is a flowchart showing the processing procedure of the processing executed in the evaluation device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The risk assessment system S described below includes a lighting device 1 and an evaluation device 100. The lighting device 1 includes an imaging unit (camera 11) capable of capturing an image of the lighting space SP. The evaluation device 100 detects the state of an object O related to the occurrence of a dangerous event in the lighting space SP based on the image captured by the imaging unit, and evaluates the risk of the dangerous event in the lighting space SP based on the detected state of the object O.

[0009] The evaluation device 100 described below detects the state of the target O over a predetermined period based on images taken over that period, and evaluates the risk based on the state of the target O over that period.

[0010] The evaluation device 100 described below evaluates risk based on at least one of the frequency with which the state of the target O becomes a specific state in a predetermined period of time and the duration for which the specific state continues.

[0011] The evaluation device 100 described below detects the state of each of the multiple targets O and evaluates the risk based on the state of each of the multiple targets O.

[0012] The evaluation device 100 described below calculates a score for each of a plurality of objects O indicating the risk for each of the objects O, and sets the total score calculated based on the score for each object as the evaluation result of the risk in the illumination space SP.

[0013] The evaluation device 100 described below outputs a report showing the results of the risk evaluation.

[0014] The risk explained below is an index that indicates the degree of at least one of the frequency of occurrence of a dangerous event and the severity of the dangerous event.

[0015] The lighting device 1 described below includes a light source unit 10, an imaging unit (camera 11), and a control unit 20. The light source unit 10 illuminates the lighting space SP. The imaging unit is capable of capturing an image of the lighting space SP. The control unit 20 detects the state of an object O related to the occurrence of a dangerous event in the lighting space SP based on the image captured by the imaging unit, and evaluates the risk of the dangerous event in the lighting space SP based on the detected state of the object O.

[0016] Hereinafter, a risk assessment system and a lighting device according to an embodiment will be described with reference to the drawings. The same components in the embodiments are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0017] Fig. 1 is a diagram showing an example of the configuration of a risk assessment system according to an embodiment. The risk assessment system S shown in Fig. 1 is a system that is installed in a relatively large facility, such as a factory, where a large number of people are working and equipment is in operation, and that assesses the risk of accidents, disasters, and the like that may occur during work in the facility.

[0018] As shown in Fig. 1, the risk assessment system S includes a lighting device 1, an evaluation device 100, and a terminal device 200. In the risk assessment system S shown in Fig. 1, the lighting device 1, the evaluation device 100, and the terminal device 200 are connected by a communication network such as Ethernet (registered trademark). The risk assessment system S may also be incorporated into a lighting control system that performs lighting control of multiple lighting devices 1. In other words, the evaluation device 100 shown in Fig. 1 may be incorporated into a lighting control device that controls multiple lighting devices 1.

[0019] The lighting device 1 is a lighting device that illuminates a predetermined lighting space SP of a facility or the like. The lighting device 1 is, for example, a lighting device that is directly attached to a ceiling surface and illuminates a floor surface from the ceiling. Note that FIG. 1 shows a case where the lighting space SP is a work site such as a factory, and equipment F, workers P (manufacturing workers or maintenance workers), etc. are present in the lighting space SP.

[0020] 1, the lighting device 1 includes a light source unit 10 and a camera 11. The light source unit 10 includes a light emitting element such as an LED (Light Emitting Diode), and irradiates light from the ceiling toward the floor of an illumination space SP.

[0021] The camera 11 is an imaging unit capable of capturing an image of the illumination space SP, and is built into the lighting device 1. The camera 11 has an angle of view facing the illumination space SP from the ceiling toward the floor. The camera 11 is, for example, a camera equipped with a fisheye lens.

[0022] The evaluation device 100 is a server device that evaluates risks in the lighting space SP. The evaluation device 100 may be a server device installed in a facility that has the lighting space SP, or may be a server device installed outside the facility. The evaluation device 100 may also be realized by a cloud system. The evaluation device 100 may also be incorporated into the lighting device 1 or the terminal device 200.

[0023] The terminal device 200 is a terminal device installed in a facility having an illumination space SP. The terminal device 200 is operated by, for example, a manager or an employee of the facility. The terminal device 200 can be any terminal device such as a smartphone, a tablet PC, a notebook PC, or a desktop PC.

[0024] Next, an example of the operation of the risk assessment system S will be described with reference to Fig. 1. In the above configuration, the risk assessment system S detects the state of an object O related to the occurrence of a dangerous event in the lighting space SP based on an image from the camera 11, and evaluates the risk of the dangerous event in the lighting space SP based on the detected state of the object O.

[0025] Specifically, first, the lighting device 1 captures an image of the illumination space SP with the camera 11 and transmits the captured image to the evaluation device 100 (step S1). More specifically, the camera 11 captures images of the illumination space SP continuously at regular intervals over a predetermined period of time. The captured image may be transmitted to the evaluation device 100 each time it is captured, or may be transmitted to the evaluation device 100 when images for a predetermined period have been accumulated.

[0026] Next, the evaluation device 100 detects an object O present in the illumination space SP based on the image acquired from the illumination device 1 (step S2). Specifically, the evaluation device 100 detects an object O such as equipment F or a worker P. The detection of the object O is performed by, for example, template matching, detection using image feature amounts (pixel values), skeleton detection, etc. In addition, the object O is The object is not limited to an object such as equipment F or a worker P, but may also be a work space (a space for manufacturing work or a space for maintenance). For example, when the floor color is color-coded according to the work space, the work space can be detected by detecting the color from an image. Alternatively, for example, the work space can be detected by detecting the area where the worker P stays in equipment F as the work space based on the movement (position change) of the worker P over a predetermined period of time.

[0027] Next, the evaluation device 100 detects the state of the detected object O (step S3). When multiple objects O are detected, the evaluation device 100 detects the state of each object O. Specifically, the evaluation device 100 detects changes in the state of the object O over a predetermined period from images taken over that period. Specifically, the evaluation device 100 detects the operating state of the equipment F, the frequency of maintenance, the size of the surrounding space, the amount of traffic in the vicinity, etc. as the state of the object O.

[0028] More specifically, the evaluation device 100 detects the operating status of the equipment F, such as whether the equipment F is operating and the operating time, by using image differences or optical flow between images taken over a predetermined period of time. Furthermore, if the worker P stays in a specific area (maintenance area) around the equipment F for a predetermined period of time or more and touches the equipment F, the evaluation device 100 determines that the worker P is performing maintenance on the equipment F. The evaluation device 100 then detects the number of times that maintenance is determined to be performed within the predetermined period as the maintenance frequency. Furthermore, the evaluation device 100 detects the size of the space surrounding the equipment F. More specifically, the evaluation device 100 detects the size of the maintenance area for the equipment F. For example, the evaluation device 100 detects stationary objects present in the maintenance area and detects the area in the maintenance area other than the area occupied by the stationary objects as the size of the surrounding space. Alternatively, if the color of the floor of the maintenance area is color-coded from the colors of other areas, the evaluation device 100 may use the color of the floor of the maintenance area as a reference color and identify areas with colors other than the reference color as areas where stationary objects exist. Furthermore, the evaluation device 100 counts people such as the worker P who pass through the periphery of the maintenance area in the images taken over a predetermined period of time, and detects the counted number of people as the traffic volume.

[0029] Next, the evaluation device 100 evaluates the risk of a dangerous event in the lighting space SP based on the detected state of the object O (step S4). The dangerous event is an accident, a disaster, or the like. The evaluation device 100 evaluates the risk, which is an index indicating the degree of at least one of the frequency of accidents and disasters and the severity of a dangerous event when it occurs. Note that a specific risk evaluation method will be described later.

[0030] Next, the evaluation device 100 creates a report showing the risk evaluation results and outputs the created report to the terminal device 200 (step S5). The report is a report in which a score showing the risk is written, and details will be described later.

[0031] As described above, the risk assessment system S according to the embodiment detects the actual state of the object O from the image captured by the camera 11 and performs risk assessment. This allows risk assessment to be performed in accordance with the actual situation at the work site, making it possible to perform risk assessment with high accuracy. Furthermore, in the risk assessment system S, the irradiation direction of the light source unit 10 and the angle of view of the camera 11 are aligned, so shadows caused by the irradiation of the light source unit 10 are prevented from appearing in the image of the camera 11, making it possible to perform image analysis for risk assessment with high accuracy. In other words, risk assessment can be performed with high accuracy.

[0032] Next, a configuration example of the lighting device 1 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing a configuration example of the lighting device 1 according to an embodiment. As shown in Fig. 2, the lighting device 1 includes a light source unit 10, a camera 11, a communication unit 12, a control unit 20, and a storage unit 30.

[0033] The light source unit 10 has a light emitting element such as an LED, and illuminates the illumination space SP. The camera 11 is a camera that captures an image of the illumination space SP illuminated by the light source unit 10.

[0034] The communication unit 12 is a network device for performing wireless communication processing and wired communication processing. For example, the communication unit 12 transmits and receives various information to and from the evaluation device 100 via a predetermined network.

[0035] Here, the lighting device 1 includes, for example, a computer having a central processing unit (CPU), read only memory (ROM), random access memory (RAM), flash memory, input / output ports, and various other circuits.

[0036] The CPU of the computer functions as the control unit 20 by, for example, reading and executing a program stored in the ROM.

[0037] Furthermore, at least one or all of the functions of the control unit 20 can be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0038] The storage unit 30 corresponds to, for example, a RAM or a flash memory. The RAM or flash memory can store information about various programs. The lighting device 1 may also acquire the programs and various information from other computers or portable recording media connected via a wired or wireless network.

[0039] The control unit 20 continuously captures images of the illumination space SP at regular intervals over a predetermined period of time. The control unit 20 transmits the images captured by the camera 11 to the evaluation device 100 via the communication unit 12. When the control unit 20 receives a risk notification signal indicating that the evaluation result of the evaluation device 100 indicates a high risk, the control unit 20 changes the illumination mode of the light source unit 10 to notify the outside that the risk is high. For example, the control unit 20 changes the illumination mode from a constant illumination state to a flashing state. This makes it possible to notify the outside, such as employees, that the risk is high.

[0040] Furthermore, when the evaluation device 100 is incorporated into the lighting device 1, the control unit 20 performs the processing of the evaluation device 100. That is, the control unit 20 detects the state of the object O related to the occurrence of a dangerous event in the lighting space SP based on the image captured by the camera 11, and evaluates the risk of the dangerous event in the lighting space SP based on the detected state of the object O.

[0041] Next, a configuration example of the evaluation device 100 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing a configuration example of the evaluation device 100 according to the embodiment. As shown in Fig. 3, the evaluation device 100 includes a communication unit 110, a control unit 120, and a storage unit 130. The control unit 120 includes an acquisition unit 121, a detection unit 122, an evaluation unit 123, and an output unit 124. The storage unit 130 stores evaluation item information 131 and report information 132.

[0042] The communication unit 110 is a network device for performing wireless communication processing and wired communication processing. For example, the communication unit 110 transmits and receives various types of information to and from the lighting device 1 and the terminal device 200 via a predetermined network.

[0043] Here, the evaluation device 100 includes, for example, a computer having a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), flash memory, input / output ports, and various other circuits.

[0044] The CPU of the computer functions as the acquisition unit 121, detection unit 122, evaluation unit 123, and output unit 124 of the control unit 120, for example, by reading and executing a program stored in the ROM.

[0045] Furthermore, at least one or all of the acquisition unit 121, detection unit 122, evaluation unit 123 and output unit 124 of the control unit 20 can be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0046] The storage unit 30 corresponds to, for example, a RAM or a flash memory. The RAM or flash memory can store evaluation item information 131, report information 132, information on various programs, etc. The evaluation device 100 may also acquire the above-mentioned programs and various information via another computer or portable recording medium connected via a wired or wireless network.

[0047] The evaluation item information 131 is information about evaluation items for evaluating the risk of a hazardous event. The evaluation unit 123, which will be described later, performs risk evaluation by referring to the evaluation item information 131. Fig. 4 is a diagram showing an example of the evaluation item information 131. As shown in Fig. 4, the evaluation item information 131 has items such as "evaluation item ID," "evaluation item," "category," "score," and "evaluation criteria."

[0048] "Evaluation item ID" is identification information that identifies each evaluation item. "Evaluation item" is information that indicates the content of the evaluation item and the general name of the evaluation item. "Category" is information that indicates the evaluation category for the evaluation item. "Score" is information that indicates the score that indicates the risk for the evaluation item. "Evaluation criteria" is information that indicates the evaluation criteria for each category.

[0049] The evaluation unit 123, which will be described later, evaluates the risk by comparing the state of the target O indicated by the evaluation item with the evaluation criteria and determining a category and score for each evaluation item, but details of this will be described later.

[0050] The report information 132 is information about a report that indicates the evaluation result generated by the evaluation unit 123. The report information 132 is updated every time an evaluation result is generated by the evaluation unit 123. FIG. 5 is a diagram showing an example of the report information 132. As shown in FIG. 5, the report information 132 has items such as "risk ID," "location," "risk content," and "risk estimate." Furthermore, the "risk estimate" further has sub-items such as "severity," "operating status," "maintenance frequency," "surrounding space," "traffic volume," and "risk."

[0051] "Risk ID" is identification information that identifies the hazardous event indicated by the evaluation result. "Location" is information that indicates the location where the hazardous event will occur. "Risk content" is information that indicates the content of the hazardous event. "Risk estimate" is information that indicates the evaluation result by the evaluation unit 123.

[0052] The evaluation unit 123, which will be described later, issues a new risk ID each time it generates an evaluation result, thereby updating the report information 132. The details of the report information 132 will be described later.

[0053] Next, the functions of the control unit 120 (the acquisition unit 121, the detection unit 122, the evaluation unit 123, and the output unit 124) will be described.

[0054] The acquisition unit 121 acquires images of the illumination space SP captured by the camera 11 of the lighting device 1. More specifically, the acquisition unit 121 acquires images of the illumination space SP captured continuously at regular intervals over a predetermined period. The predetermined period is, for example, working hours at a facility. Alternatively, the predetermined period may be the operating time (production time) of a production line.

[0055] The detection unit 122 detects an object O present in the illumination space SP based on an image acquired from the lighting device 1. Specifically, the detection unit 122 detects the object O such as equipment F or a worker P. The detection of the object O is performed by, for example, template matching, detection using image features (pixel values), skeletal detection, or the like. Furthermore, the object O is not limited to objects such as equipment F or a worker P, but may also be a work space (a space for manufacturing work or a space for maintenance). For example, when the color of the floor is color-coded according to the work space, the work space can be detected by detecting the color from the image. For example, the work space can be detected by, for example, detecting the area where the worker P stays in equipment F as the work space based on the movement (position change) of the worker P over a predetermined period of time.

[0056] Next, the detection unit 122 detects the state of the detected object O. When multiple objects O are detected, the detection unit 122 detects the state of each object O. Specifically, the detection unit 122 detects that the state of the object O is a specific state during a predetermined period from images taken during that period. Specifically, the detection unit 122 detects the operating state of the equipment F, the frequency of maintenance, the size of the surrounding space, the amount of traffic in the vicinity, etc. as the specific state of the object O.

[0057] More specifically, the detection unit 122 detects the operating status, such as whether the equipment F is operating and the operating time, by using image differences or optical flow between images taken over a predetermined period of time. Furthermore, if the worker P stays in a specific area (maintenance area) around the equipment F for a predetermined period of time or more and touches the equipment F, the detection unit 122 determines that the worker P is performing maintenance on the equipment F. The detection unit 122 then detects the number of times that it is determined that maintenance is being performed within the predetermined period as the maintenance frequency. Furthermore, the detection unit 122 detects the size of the space surrounding the equipment F. More specifically, the detection unit 122 detects the size of the maintenance area for the equipment F. For example, the detection unit 122 detects stationary objects present in the maintenance area, and detects areas in the maintenance area other than the area occupied by the stationary objects as the size of the surrounding space. Alternatively, if the floor of the maintenance area is color-coded differently from the colors of other areas, the detection unit 122 may use the color of the floor of the maintenance area as a reference color and identify areas with a color other than the reference color as areas where stationary objects exist. Furthermore, the detection unit 122 counts people such as workers P who pass through the periphery of the maintenance area in images taken over a predetermined period of time, and detects the counted number of people as the traffic volume.

[0058] The evaluation unit 123 evaluates the risk of a hazardous event in the lighting space SP based on the detected state of the object O. The hazardous event is an accident, a disaster, or the like. The evaluation unit 123 evaluates the risk, which is an index showing the degree of at least one of the frequency of accidents and disasters and the severity of a hazardous event when it occurs. Specifically, the evaluation unit 123 evaluates the risk based on at least one of the frequency with which the object O detected by the detection unit 122 enters a specific state and the duration for which the specific state continues. The frequency with which the specific state is entered is, for example, the maintenance frequency. Furthermore, the duration is the operating state (the time during which the equipment F is operating). This allows the evaluation unit 123 to perform a highly accurate risk evaluation of a specific state that is highly related to a hazardous event.

[0059] Furthermore, the evaluation unit 123 calculates a score for each of the multiple targets O indicating the risk for each of the targets O, and sets the overall score calculated based on the score for each target as the evaluation result of the risk in the lighting space SP. Specifically, the evaluation unit 123 calculates the score for each target O with reference to the evaluation item information 131.

[0060] For example, as shown in FIG. 4, when the detection unit 122 detects that the operating time is 90% or more of the working hours for the evaluation item "operating status," the evaluation unit 123 identifies the category "high" and calculates a score of "5," which is the score for each target. Similarly, the evaluation unit 123 identifies a category for each evaluation item in the evaluation item information 131 and calculates a score for each target. In this way, by performing risk evaluation based on the status of multiple targets O, risk evaluation can be performed with higher accuracy. Furthermore, by calculating the score for each target and calculating a total score based on the score for each target, risk evaluation can be performed quantitatively.

[0061] Then, the evaluation unit 123 calculates a total score based on the calculated scores for each subject, creates a report with the total score as the evaluation result, and updates the report information 132.

[0062] For example, as shown in FIG. 5, the evaluation unit 123 creates a report that includes the calculated scores for each object and a total score. In the example shown in FIG. 5, the evaluation unit 123 creates a report in which the score for each object for the evaluation item "operating status" is "5," the score for each object for the evaluation item "maintenance frequency" is "3," the score for each object for the evaluation item "surrounding space" is "1," and the score for each object for the evaluation item "traffic volume" is "3." The scores for "severity" shown in FIG. 5 are manually input by an operator or a manager. Note that the "severity" may be automatically input by the evaluation unit 123 with reference to the severity calculation table shown in FIG. 6. FIG. 6 shows information representing the severity calculation table. The severity calculation table is stored, for example, in the storage unit 130 of the evaluation device 100. In this case, the evaluation unit 123 receives information on damage that may occur due to a hazardous event from an operator or a manager, compares the information with the "criteria" in FIG. 6, and determines the "severity" and "score."

[0063] Then, the evaluation unit 123 calculates "risk," which is a total score, based on the subject score and the severity score. In the example shown in Fig. 5, the evaluation unit 123 calculates "22," which is the total of the subject score and the severity score, as the "risk." Note that the method of calculating the total score ("risk" in Fig. 5) is not limited to the total value, but may also be the average value, maximum value, minimum value, median value, etc.

[0064] The output unit 124 outputs a report based on the report information 132 to the terminal device 200. The report may be output by displaying the report information 132 in its original display format, or may be output in a format that displays only the overall score. In this way, the output unit 124 outputs a report based on the report information 132, allowing workers, managers, etc. to understand the risk assessment results.

[0065] Next, the processing procedure of the processing executed by the evaluation device 100 according to the embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the processing procedure of the processing executed by the evaluation device 100 according to the embodiment.

[0066] As shown in FIG. 7, the control unit 120 acquires images for a predetermined period from the lighting device 1 (step S101).

[0067] Next, the control unit 120 detects the state of the object O during the predetermined period based on the acquired images during the predetermined period (step S102).

[0068] Next, the control unit 120 calculates a score for each object based on the state of each detected object O (step S103).

[0069] Next, the control unit 120 calculates a total score based on the calculated scores for each subject (step S104).

[0070] Next, the control unit 120 creates a report in which the calculated total score and the score for each subject are entered, and updates the report information 132 (step S105).

[0071] Next, the control unit 120 outputs the created report to the terminal device 200 (step S106), and the process ends.

[0072] As described above, the risk assessment system S according to the embodiment includes a lighting device 1 and an evaluation device 100. The lighting device 1 includes an imaging unit (camera 11) capable of capturing an image of the lighting space SP. The evaluation device 100 detects the state of an object O related to the occurrence of a dangerous event in the lighting space SP based on the image captured by the imaging unit, and evaluates the risk of the dangerous event in the lighting space SP based on the detected state of the object O. This allows for highly accurate risk assessment.

[0073] Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included within the scope and spirit of the invention, as well as the invention described in the claims and their equivalents. [Explanation of symbols]

[0074] 1. Lighting equipment 10 Light source section 11 Camera 12, 110 Communications Department 20, 120 Control unit 30, 130 storage section 100 Evaluation Device 121 Acquisition Department 122 Detector 123 Evaluation Department 124 Output section 131 Evaluation Item Information 132 Report Information 200 Terminal Device F equipment O Target P worker S Risk Assessment System SP lighting space

Claims

1. a lighting device equipped with an imaging unit capable of imaging the illumination space; an evaluation device that detects a state of an object related to the occurrence of a hazardous event in the lighting space based on an image captured by the imaging unit, and evaluates a risk of the hazardous event in the lighting space based on the detected state of the object; A risk assessment system comprising:

2. The evaluation device Detecting a state of the subject during a predetermined period based on the images during the predetermined period, and assessing the risk based on the state of the subject during the predetermined period. The risk assessment system of claim 1 .

3. The evaluation device The risk is evaluated based on at least one of the frequency with which the subject's condition becomes a specific condition during the predetermined period and the duration for which the specific condition continues. The risk assessment system according to claim 2 .

4. The evaluation device Detecting a state of each of a plurality of said subjects and assessing said risk based on the state of each of said plurality of subjects. The risk assessment system of claim 1 .

5. The evaluation device A score for each of the plurality of objects indicating the risk is calculated, and a total score calculated based on the scores for each of the plurality of objects is used as an evaluation result of the risk in the lighting space. The risk assessment system according to claim 4.

6. The evaluation device Output a report showing the results of the risk assessment The risk assessment system of claim 1 .

7. The risk is: An index showing the degree of at least one of the frequency of occurrence of the hazardous event and the severity of the hazardous event. The risk assessment system of claim 1 .

8. a light source unit that illuminates the lighting space; an imaging unit capable of imaging the illumination space; a control unit that detects a state of an object related to the occurrence of a hazardous event in the lighting space based on an image captured by the imaging unit, and evaluates a risk of the hazardous event in the lighting space based on the detected state of the object; A lighting device comprising:

Images