JP7530789B2 - Lighting Control System - Google Patents

Description

The present invention relates to a lighting control system, and in particular to a lighting control system for a room equipped with a light-transmitting window.

JP 2010-9874 A (Patent Document 1) discloses a lighting control system that performs lighting control suited to the perception of the occupants in a lighting space with windows. In this lighting control system, multiple CCD cameras installed on the wall capture images of the person's field of vision, and dimming control of lighting fixtures is performed based on the luminance distribution of the windows in the images and the luminance of the windows.

In addition, JP 2019-200938 A (Patent Document 2) discloses that under conditions where daylight enters through a window, a daylight correction value is calculated based on the illuminance value of reflected light detected by an illuminance sensor installed on the ceiling, and dimming control of a lighting fixture is performed to obtain an illuminance value obtained by subtracting the daylight correction value from the target illuminance value.

JP 2010-9874 A JP 2019-200938 A

In Patent Document 1, it is necessary to capture images of a person's field of view using multiple CCD cameras, which makes the processing complicated. In addition, because CCD cameras recognize people's faces, it is difficult to apply the technology in Patent Document 1 to office buildings (office-type buildings) where many people are seated in the rooms.

In addition, in Patent Document 2, an illuminance sensor installed on the ceiling detects light reflected off flooring materials, etc., but if the illuminance sensor is installed facing downwards, the detected value may vary depending on the position and color of furniture such as desks placed in the room. Also, if blinds are installed on the window surface, reflected light reflected off the blind blades may enter the illuminance sensor located near the window, causing the illuminance sensor near the window to detect an illuminance value that is higher than the actual value. In such cases, the lighting fixtures near the window will be dimmed, which can cause the room to become dark.

The present invention has been made to solve the above problems, and its purpose is to provide a lighting control system that can adjust the light level to a comfortable level for occupants with a simple configuration.

A lighting control system according to one aspect of the present invention is a lighting control system for a room provided with a light-transmitting window, and includes a plurality of lighting fixtures installed on the ceiling of the room, a plurality of illuminance sensors arranged on the wall surface of the room, and a dimming control means for dimming the plurality of lighting fixtures based on the detection values of the plurality of illuminance sensors. The plurality of illuminance sensors include a facing sensor facing the direction of the window and a non-facing sensor facing a direction different from the window.

Preferably, during times of daylight, the dimming control means dims the lighting fixtures located in the window area close to the window among the plurality of lighting fixtures in accordance with the detection value by the facing sensor, and dims the lighting fixtures located in the remote area far from the window in accordance with the detection value by the non-facing sensor.

Preferably, the lighting control system further includes a storage means for storing a daytime illuminance threshold value determined by the facing sensor. In the "appropriate illuminance range" where the detection value by the facing sensor is higher than the lower limit value and equal to or lower than the illuminance threshold value, the dimming control means desirably dims the lighting fixtures located in the window-side area at a reference degree, and in the "high illuminance condition" where the detection value by the facing sensor exceeds the illuminance threshold value, the dimming control means desirably dims the lighting fixtures located in the window-side area at a degree higher than the reference degree.

When the detection value by the facing sensor is within the appropriate illuminance range or in a high illuminance condition, it is more desirable for the dimming control means to control the dimming of lighting fixtures located in the remote area so that the amount of dimming decreases the further away from the window they are.

The dimming control means may control the lighting fixtures located in the remote area by maintaining the dimming state in the appropriate illuminance range when the detection value by the facing sensor changes from the appropriate illuminance range to a high illuminance condition.

Preferably, in low illuminance conditions where the detection value by the facing sensor is equal to or lower than the lower limit, the dimming control means dims the lighting fixtures located in the window area to a level lower than the reference level.

Preferably, the non-facing sensor includes a first sensor arranged facing away from the window and a second sensor arranged facing in a direction intersecting the detection direction of the first sensor.

The present invention allows for dimming with a simple configuration that makes occupants feel comfortable.

1A and 1B are diagrams showing a schematic configuration of a lighting control system according to an embodiment of the present invention, in which (A) is a vertical cross-sectional view and (B) is a plan view. 1A is a block diagram showing a functional configuration of a lighting control system according to an embodiment of the present invention, and FIG. 1B is a flowchart showing a lighting control method in the embodiment of the present invention. 13A is a flowchart showing a method for setting a target illuminance for each illuminance sensor, and FIG. 13B is a flowchart showing a method for setting a daytime illuminance threshold value for a facing illuminance sensor. FIG. 1 is a diagram illustrating a schematic configuration of a typical lighting control system.

The embodiment of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

(General configuration)
FIG. 1 is a diagram showing a schematic configuration of a lighting control system 1 according to the present embodiment, where (A) is a vertical cross-sectional view and (B) is a plan view.

The lighting control system 1 controls a plurality of lighting fixtures 2 installed on the ceiling 92 of a room 9. The room 9 is a room in an office building, and a plurality of desks 81 are installed inside the room 9.

The room 9 has a generally rectangular shape (rectangular or square) in plan view, and of the walls 93-96 surrounding the room 9, for example, one wall 93 is provided with a light-transmitting window 11. In this embodiment, the wall 93 with the window 11 provided therein is referred to as the outer wall 93, and the wall 94 facing the outer wall 93 is referred to as the facing wall 94. In addition, a pair of walls 95, 96 that intersect (orthogonally) with the outer wall 93 are referred to as the side walls 95, 96. The facing wall 94 and the side walls 95, 96 are outer walls or partition walls.

As shown in FIG. 1(B), the window 11 is provided over a wide area, leaving both ends of the exterior wall 93 in the width direction. The upper end of the window 11 is located near the height of the ceiling 92 (for example, within a range of 20 cm or less from the ceiling 92). On the indoor side of the window 11, a blind 12 capable of covering the entire indoor surface of the window 11 is provided. The blind 12 has multiple blades whose angle can be adjusted in the vertical direction, and can be rolled up, for example.

The lighting fixtures 2 are aligned in a plan view along the width direction of the side walls 95, 96 (hereinafter referred to as the "X direction") and the width direction of the outer wall 93 (hereinafter referred to as the "Y direction"). Note that it is sufficient that multiple lighting fixtures 2 are provided at least along the X direction. The shape of the lighting fixtures 2 is not limited to a rectangular shape having a length in the Y direction as shown in the figure.

Figure 4 shows the schematic configuration of a typical lighting control system 100. The lighting control system 100 has multiple illuminance sensors 103 mounted facing downward on the ceiling 92, predicts the illuminance on the desk surface from the light incident on the illuminance sensors 103, and controls the lighting fixtures 102 based on the prediction results. Each lighting fixture 102 is controlled based on the prediction results from the illuminance sensors 103 placed nearby.

In such a system 100, depending on the inclination of the blades of the blinds 12, there is a possibility that upward sunlight may enter directly into the illuminance sensor 103. In such a case, the predicted illuminance by the illuminance sensor 103 placed in the area near the window 11 may be higher than the actual illuminance, and the lighting fixtures 102 in the area near the window 11 may be significantly dimmed, resulting in a problem of lower illuminance than the actual required illuminance.

In contrast, the lighting control system 1 according to this embodiment is configured such that the illuminance sensor is provided on the wall of the room 9, rather than on the ceiling 92, to reduce the effect of upward light entering through the window 11. The wall of the room 9 is typically the inner wall surface of the walls 93-96, but may also be, for example, the vertical surface of a sensor mounting member installed parallel to the walls 93-95.

Referring again to FIG. 1(A), the lighting control system 1 includes multiple illuminance sensors 3a, 3b, and 3c. The illuminance sensor 3a is disposed on one side wall 95, facing the other side wall 96. The illuminance sensor 3b is disposed on the facing wall 94, facing the window 11 of the exterior wall 93. The illuminance sensor 3c is disposed in a portion of the exterior wall 93 other than the window 11, facing the opposite direction of the window 11 (towards the facing wall 94). In this way, the illuminance sensors 3a to 3c are disposed in different orientations in the horizontal direction.

The illuminance sensor 3b is a facing sensor facing the direction of the window 11, and senses the brightness of the part of the window 11 including the blinds 12. The illuminance sensors 3a and 3c are non-facing sensors facing a different direction from the window 11, and sense the brightness of the entire space in the room 9 from different directions (X and Y directions). The detection direction of the illuminance sensor 3a is the Y direction, and the detection direction of the illuminance sensor 3c is the X direction. Depending on the size of the room 9, etc., multiple illuminance sensors 3a may be provided at intervals from each other along the X direction. An illuminance sensor may also be provided on the other side wall 95. Multiple illuminance sensors 3b and 3c may also be provided.

It is desirable that the installation height of the illuminance sensors 3a to 3c is within the height range of the window 11 and is at least above the head height of a person (for example, at least 180 cm above the floor 91). This allows the illuminance sensors 3a to 3c to detect illuminance without being affected by people's movements as much as possible.

In the following description, when it is necessary to distinguish between the illuminance sensors 3a to 3c, the illuminance sensor 3b will be referred to as the facing illuminance sensor 3b, and the illuminance sensors 3a and 3c will be referred to as the non-facing illuminance sensors 3a and 3c.

(Functional configuration)
2(A) is a block diagram showing the functional configuration of the lighting control system 1. The lighting control system 1 includes a control device 4 electrically connected to a plurality of lighting fixtures 2 and a plurality of illuminance sensors 3a to 3c. The control device 4 includes a control unit 41 that controls the entire lighting control system 1, a storage unit 42 that stores various data and programs, and a clock unit 43 that performs a clocking operation. The control unit 41 is realized by a processor such as a CPU (Central Processing Unit). The storage unit 42 is composed of a non-volatile memory. The clock unit 43 measures the current date and time.

The memory unit 42 stores illuminance control information 44. The illuminance control information 44 includes the target illuminance (target value) of each of the illuminance sensors 3a to 3c, and the daytime illuminance threshold value of the facing illuminance sensor 3b. These values included in the illuminance control information 44 are set in advance for the room 9, and are stored in advance in the memory unit 42. Note that the lighting control system 1 itself may have a function for setting the illuminance control information 44. In the latter case, the lighting control system 1 further includes a setting measuring device 5. The setting measuring device 5 typically includes a desk surface illuminance sensor.

The control unit 41 functions as a dimming control means, and controls the dimming of the multiple lighting fixtures 2 based on the illuminance control information 44 and the detection values of the illuminance sensors 3a to 3c. Because the illuminance sensors 3a to 3c are provided on the wall surface rather than on the ceiling 92, the control unit 41 controls the multiple lighting fixtures 2 based on the amount of light entering the eye (perception of brightness) rather than the predicted value of the desk surface illuminance.

Specifically, during times when there is no sunlight (nighttime), the control unit 41 uniformly controls the dimming of the multiple lighting fixtures 2 using the target values of the illuminance sensors 3a-3c as indexes. On the other hand, during times when there is sunlight, the control unit 41 controls the dimming separately for the lighting fixtures 2a located in the window region R1 close to the window 11 and the lighting fixtures 2b located in the other region, i.e., the remote region R2 far from the window 11. With reference to FIG. 1(B), the window region R1 is the window region of the exterior wall 93, the so-called perimeter zone, which is an area that is greatly affected by the lighting from the window 11, and the distance L1 is, for example, 3 m to 6 m.

In this embodiment, during times of daylight, the control unit 41 dims the lighting fixture 2a located in the window region R1 in accordance with the detection value of the facing illuminance sensor 3b, and controls the dimming of the lighting fixture 2b located in the remote region R2 in accordance with the detection value of the non-facing illuminance sensors 3a and 3c.

As shown in FIG. 2(A), the lighting control system 1 may further include an alarm unit 6 configured with an audio speaker or the like.

(How to set target illuminance)
FIG. 3A is a flowchart showing a method for setting the target illuminance of each of the illuminance sensors 3a to 3c.

During times when there is no influence of daylight, such as at night, the desk surface illuminance is measured using the desk surface illuminance sensor (step S102). The person setting the desk determines the required desk surface illuminance while observing the perceived brightness of the room 9, and determines the maximum output of each lighting fixture 2 accordingly (step S104). In addition, the values (illuminance) detected by each illuminance sensor 3a to 3c at maximum output are stored in the memory unit 42 as target values (step S106). In the following explanation, the target value of the non-facing illuminance sensor 3a is referred to as "ESA", the target value of the facing illuminance sensor 3b is referred to as "ESB", and the target value of the non-facing illuminance sensor 3c is referred to as "ESC".

(How to set the daytime illuminance threshold)
FIG. 3B is a flow chart showing a method for setting the daytime illuminance threshold value of the facing illuminance sensor 3b.

During the daytime on a sunny day, all lighting fixtures 2 are turned off (step S112). With the slats of the blinds 12 fixed at a desired angle, the horizontal illuminance of the windowside area R1 is measured by the desk illuminance sensor. When the horizontal illuminance of the windowside area R1 reaches the target illuminance (e.g., 500 lx) (YES in step S114), the value (illuminance) of the facing illuminance sensor 3b at that time is stored in the memory unit 42 as the daytime illuminance threshold value (step S116). The daytime illuminance threshold value corresponds to the maximum value when the windowside area R1 is at a comfortable brightness. In the following explanation, the daytime illuminance threshold value of the facing illuminance sensor 3b is referred to as "ELB".

(Lighting control method)
Fig. 2(B) is a flowchart showing a lighting control method according to the present embodiment. Each process shown in Fig. 2(B) is realized by the control unit 41 shown in Fig. 2(A) reading and executing a program stored in advance in the storage unit 42, for example.

2(A) and (B), the control unit 41 first determines whether the current time measured by the timing unit 43 is in a time zone with sunlight (step S2). If the current time is in a time zone with no sunlight (after sunset), the process proceeds to step S4. If the current time is in a time zone with sunlight (morning, midday, before sunset), the process proceeds to step S6. Note that since the time of sunset differs depending on the season, it is desirable to change the time used as the judgment criterion for each season.

In step S4, because there is no effect of sunlight from the window 11, normal lighting control is performed with the target values of the illuminance sensors 3a to 3c set to the above-mentioned "ESA", "ESB", and "ESC". In other words, the dimming of the multiple lighting devices 2 is controlled so that the detection values of the illuminance sensors 3a to 3c match or approach the target values ESA, ESB, and ESC included in the illuminance control information 44 stored in the memory unit 42.

In step S6, it is determined whether the detection value of the facing illuminance sensor 3b is higher than the lower limit and is equal to or lower than the daytime illuminance threshold ELB, i.e., whether it is within the "appropriate illuminance range." The lower limit is, for example, 200 lx.

If the detection value of the facing illuminance sensor 3b is within the "appropriate illuminance range," the lighting fixture 2a in the window area R1 is dimmed to a standard degree (step S10). Specifically, the lighting fixture 2a is controlled to be, for example, 30% of its nighttime output (maximum output). The lighting fixture 2b in the remote area R2 is controlled so that the detection values of the non-facing illuminance sensors 3a and 3c match or approach the target values ESA and ESC, respectively. Note that lighting fixture 2b may be controlled based on the average value (excluding outliers) of the non-facing illuminance sensors 3a and 3c.

When the detection value of the facing illuminance sensor 3b is equal to or lower than the lower limit, i.e., when the sunlight is too little and the illuminance is low, the lighting fixtures 2a in the window area R1 are dimmed to a level lower than the reference level (step S8). Specifically, the lighting fixtures 2a are controlled to be, for example, 60% of their nighttime output. The lighting fixtures 2b in the remote area R2 are controlled in the same way as in step S10.

When the detection value of the facing illuminance sensor 3b exceeds the daytime illuminance threshold ELB, i.e., in the case of "high illuminance conditions" where there is excessive sunlight, the lighting fixtures 2a in the windowside area R1 are dimmed to a degree higher than the reference degree (step S12). Specifically, the lighting fixtures 2a are controlled to be, for example, 10% of their nighttime output. The lighting fixtures 2b in the remote area R2 are controlled in the same way as in step S10.

In addition, in high illuminance conditions, the blinds 12 may be open (rolled up or with the slats nearly horizontal), so it is desirable for the notification unit 6 to output a voice announcement such as "We recommend that you close the blinds" (step S14). Closing the blinds 12 reduces the amount of light entering through the window 11, making it possible to suppress glare in the room 9 and reduce the air conditioning load.

The above series of processes is repeated every fixed time (for example, every 10 seconds).

As described above, according to this embodiment, non-facing illuminance sensors 3a and 3c facing different directions are provided on the wall of room 9, so that the brightness of the entire space within room 9 can be appropriately predicted even if the luminance distribution changes due to blinds 12.

In addition to the non-facing illuminance sensors 3a and 3c, a facing illuminance sensor 3b is provided facing the window 11 (blinds 12), so that the brightness of the windowside area R1 can be properly detected during times of daylight without being affected by the blade angle of the blinds 12, etc. This can eliminate the problem of the windowside area R1 becoming dark. In other words, the space within the room 9 can be made ideally illuminant.

In addition, by providing both the facing illuminance sensor 3b and the non-facing illuminance sensors 3a, 3c, the dimming of the lighting fixtures 2a in the window area R1 can be controlled separately from the lighting fixtures 2b in the separate area R2 during times of sunlight, so that dimming that makes the occupants feel comfortable can be performed while maintaining a simple configuration. Furthermore, when brightness can be ensured by sunlight coming through the window 11, the lighting fixtures 2a in the window area R1 can be effectively dimmed, which is expected to have an energy-saving effect.

When the detection value by the facing illuminance sensor 3b is in the "appropriate illuminance range" or "high illuminance condition," it is more desirable for the control unit 41 to perform dimming control so that the amount of dimming of the lighting fixture 2b located in the separated area R2 decreases the farther it is from the window 11, as conceptually shown in FIG. 1(A).

In addition, if the illuminance value near the window 11 becomes extremely high during times of daylight, it may be assumed that there is discomfort glare, and lighting control (control that does not dim) may be performed assuming a contrast effect. In other words, if the detection value by the facing illuminance sensor 3b changes from the "appropriate illuminance range" to a "high illuminance condition," the dimming state for the "appropriate illuminance range" may be maintained and the lighting fixture 2b located in the separated area R2 may be controlled, regardless of the detection value by the non-facing illuminance sensors 3a and 3c.

(Modification)
In this embodiment, whether or not it is a time period with sunlight is determined based on the timekeeping information of the timer 43, but the presence or absence of sunlight may be determined directly by a sunshine meter (not shown).

In addition, in this embodiment, blinds 12 are provided in front of the window 11 in the room 9, but blinds 12 do not have to be provided.

In addition, in this embodiment, the window 11 is described as being provided on only one side (exterior wall 93) of the room 9, but windows 11 may be provided on multiple sides of the room 9.

The lighting control system 1 according to this embodiment can also be applied to buildings other than office buildings, such as facilities and homes.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 Lighting control system, 2, 2a, 2b Lighting fixtures, 3a, 3b, 3c Illuminance sensor, 4 Control device, 9 Room, 11 Window, 12 Blinds, 91 Floor, 92 Ceiling, 93, 94, 95, 96 Wall, R1 Window area, R2 Remote area.

Claims (6)

A lighting control system for a room provided with a light-transmitting window, comprising:
A plurality of lighting fixtures installed on the ceiling of the room;
A plurality of illuminance sensors are arranged on a wall surface portion within the room, the illuminance sensors including a facing sensor facing the window and a non-facing sensor facing a direction different from the window;
a dimming control unit that dims the lighting devices based on detection values of the plurality of illuminance sensors ;
The dimming control means, during times of sunlight, dims the lighting fixtures of the plurality of lighting fixtures located in a window area close to the window in accordance with the detection value by the facing sensor, and dims the lighting fixtures located in a remote area far from the window in accordance with the detection value by the non-facing sensor . A storage means for storing a daytime illuminance threshold value by the facing sensor is further provided,
2. The lighting control system according to claim 1, wherein the dimming control means dims the lighting fixtures located in the window-side area by a reference degree when the detection value by the facing sensor is higher than a lower limit value and is equal to or lower than the illuminance threshold value, within an appropriate illuminance range, and dims the lighting fixtures located in the window-side area by a reference degree when the detection value by the facing sensor exceeds the illuminance threshold value, in a high illuminance condition. 3. The lighting control system according to claim 2, wherein when a detection value by the facing sensor is within the appropriate illuminance range or the high illuminance condition, the dimming control means controls the dimming of the lighting fixtures located in the remote area so that the amount of dimming decreases as the lighting fixtures move away from the window. 4. The lighting control system according to claim 2, wherein the dimming control means, when a detection value by the facing sensor changes from the appropriate illuminance range to the high illuminance condition, maintains a dimming state in the appropriate illuminance range and controls the lighting device located in the separate area. 5. The lighting control system according to claim 2, wherein the dimming control means dims the lighting fixtures located in the window area to a level lower than the reference level when the detection value by the facing sensor is equal to or lower than the lower limit value, that is, in a low illuminance condition. The lighting control system of any one of claims 1 to 5, wherein the non-facing sensor includes a first sensor arranged facing in a direction opposite to the window, and a second sensor arranged facing in a direction intersecting a detection direction of the first sensor.

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