Illumination control system, illumination control method, and program

Abstract

This illumination control system (10) comprises a plurality of illumination tools (20), a plurality of illumination control devices (30), and a relay device (40). Each of the plurality of illumination control devices (30) unicast-transmits, to the relay device (40) at prescribed time intervals, a first notification signal for notifying a target dimming state to which an illumination tool (20), which belongs to a group to be controlled by the illumination control device (30), should transition at the current time. The relay device (40) unicast-transmits, to each of the plurality of illumination tools (20) at prescribed time intervals, a second notification signal that is obtained from the first notification signal received from each of the plurality of illumination tools (20) and is for notifying the target dimming state to which the plurality of illumination tools (20) should transition at the current time.

Description

Illumination control system, illumination control method, and program

[0001] The present invention relates to an illumination control system, an illumination control method, and a program.

[0002] Techniques for controlling lighting fixtures using a human presence sensor are known. In the illumination control system described in Patent Document 1, when a human body detection sensor detects a person, the lighting fixture is lit with a 100% light output, and a control signal is transmitted to an adjacent lighting fixture via a signal line, causing the adjacent lighting fixture to be lit with a 50% light output.

[0003] Japanese Patent Application Laid-Open No. 9-283282

[0004] The present invention provides an illumination control system or the like capable of alleviating communication congestion.

[0005] A lighting control system according to one aspect of the present invention comprises a plurality of lighting fixtures, a plurality of lighting control devices, and a relay device, wherein the plurality of lighting fixtures, the plurality of lighting control devices, and the relay device constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group among the plurality of lighting fixtures via unicast, and transmits a first notification signal to the relay device at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should currently transition, and the relay device controls each of the plurality of lighting control devices A second notification signal obtained from the received first notification signal, which notifies the plurality of lighting fixtures of the target dimming state to which they should transition at this time, is unicast to each of the plurality of lighting fixtures at predetermined time intervals. When each of the plurality of lighting fixtures receives the control signal, it transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. When it receives the second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs indicated by the received second notification signal.

[0006] A lighting control system according to one aspect of the present invention comprises a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group among the plurality of lighting fixtures, and transmits a first notification signal to a first lighting fixture among the plurality of lighting fixtures at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which the lighting fixtures should transition at this time, and the first lighting fixture receives from each of the plurality of lighting control devices. A second notification signal obtained from the first notification signal, which notifies the second lighting fixture of the target dimming state to which the second lighting fixture should transition at the present time, is unicast to the second lighting fixture at predetermined time intervals. When each of the multiple lighting fixtures receives the control signal, it transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. When the second lighting fixture receives the second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs indicated by the received second notification signal.

[0007] A lighting control system according to one aspect of the present invention comprises a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state using a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group among the plurality of lighting fixtures via unicast, the first lighting control device among the plurality of lighting control devices transmits a first notification signal to a second lighting control device among the plurality of lighting control devices at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which the lighting fixtures should currently transition, and the second lighting control device, when the lighting fixtures belonging to its controlled group of the current state A second notification signal, which includes the content of the first notification signal received from the first lighting control device, is transmitted unicast to each of the plurality of lighting fixtures at predetermined time intervals. This second notification signal notifies each of the plurality of lighting fixtures of the target dimming state to which they should transition at that time. When each of the plurality of lighting fixtures receives the control signal, it transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. When the second notification signal is received, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs indicated by the received second notification signal.

[0008] A lighting control method according to one aspect of the present invention is a lighting control method performed by a lighting control system comprising a plurality of lighting fixtures, a plurality of lighting control devices, and a relay device, wherein the plurality of lighting fixtures, the plurality of lighting control devices, and the relay device constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices, when it detects a change in state using a sensor it has, unicasting a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures; each of the plurality of lighting control devices, at predetermined time intervals, unicasting a first notification signal to the relay device to notify the target dimming state to which the lighting fixtures belonging to its group of controlled fixtures should transition at that time; and the relay device, The process includes the steps of: unicasting a second notification signal obtained from the first notification signal received from each of the plurality of lighting control devices, which is a second notification signal for notifying the target dimming state to which the plurality of lighting fixtures should transition at the present time, to each of the plurality of lighting fixtures at predetermined time intervals; each of the plurality of lighting fixtures, upon receiving the control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and each of the plurality of lighting fixtures, upon receiving the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state.

[0009] A lighting control method according to one aspect of the present invention is a lighting control method performed by a lighting control system comprising a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, unicasting a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures; each of the plurality of lighting control devices, at predetermined time intervals, unicasting a first notification signal to a first lighting fixture among the plurality of lighting fixtures to notify the target dimming state to which the lighting fixtures belonging to its group of controlled fixtures should transition at this time; and the first lighting fixture The process includes the steps of: unicasting a second notification signal obtained from the first notification signal received from each of the plurality of lighting control devices, which is a second notification signal for notifying the target dimming state to which the second lighting device among the plurality of lighting devices should transition at the present time, to the second lighting device at predetermined time intervals; each of the plurality of lighting devices, upon receiving the control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and when the second lighting device receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state.

[0010] A lighting control method according to one aspect of the present invention is a lighting control method performed by a lighting control system comprising a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, unicasting a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures; a first lighting control device among the plurality of lighting control devices unicasting a first notification signal to a second lighting control device among the plurality of lighting control devices at predetermined time intervals to notify the target dimming state to which the lighting fixtures belonging to its group of controlled fixtures should transition at this time; and the second lighting control device, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures The process includes the steps of: transmitting a second notification signal, which includes the content of the first notification signal received from the first lighting control device, to each of the plurality of lighting fixtures at predetermined time intervals via unicast, the second notification signal for notifying the target dimming state to which the lighting fixture should transition at the present time; each of the plurality of lighting fixtures, upon receiving the control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and each of the plurality of lighting fixtures, upon receiving the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

[0011] A program according to one aspect of the present invention is a program for causing the lighting control system to execute the lighting control method.

[0012] The lighting control system and the like of the present invention can alleviate communication congestion.

[0013] Figure 1 is a block diagram showing the configuration of a lighting control system according to an embodiment. Figure 2 is a diagram showing an indoor space to which the lighting control system according to an embodiment is applied. Figure 3 is a conceptual diagram showing a wireless mesh network. Figure 4 is an example of a sequence diagram of zone-based dimming operation of the lighting control system according to an embodiment. Figure 5 is a diagram showing a comparative example of the first notification signal transmission method. Figure 6 is a diagram showing an embodiment of the first notification signal transmission method.

[0014] The embodiments will be described in detail below with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit the present invention. Furthermore, components in the following embodiments that are not described in an independent claim will be described as optional components.

[0015] Please note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations may be omitted or simplified.

[0016] (Embodiment) [Configuration] First, the configuration of the lighting control system according to the embodiment will be described. Figure 1 is a block diagram showing the configuration of the lighting control system according to the embodiment. Figure 2 is a diagram showing an indoor space to which the lighting control system according to the embodiment is applied. As shown in Figures 1 and 2, the lighting control system 10 comprises a plurality of lighting fixtures 20, a plurality of lighting control devices 30, a relay device 40, and a management device 50. The number of plurality of lighting fixtures 20 and the number of plurality of lighting control devices 30 provided in the lighting control system 10 are not particularly limited.

[0017] The lighting fixture 20 is a base light or the like that is installed on the ceiling of the indoor space 60 to illuminate the indoor space 60. The form of the lighting fixture 20 is not particularly limited and may be a ceiling light, downlight, or spotlight, etc. Specifically, the lighting fixture 20 comprises a wireless communication unit 21, a light source 22, a control unit 23, and a storage unit 24.

[0018] The wireless communication unit 21 is a wireless communication circuit for the lighting fixture 20 to communicate wirelessly (more specifically, via radio waves) with the lighting control device 30. Specifically, the wireless communication unit 21 communicates wirelessly according to a communication standard such as BLE (Bluetooth® Low Energy) or Bluetooth® mesh, but is not particularly limited to the communication standard.

[0019] The light source 22 emits white light into the indoor space 60 so that the lighting fixture 20 can illuminate the indoor space 60. The light source 22 is implemented by, for example, an LED (Light Emitting Diode) element, but may also be implemented by other light-emitting elements such as a semiconductor laser, organic EL (Electro-Luminescence), or inorganic EL.

[0020] The control unit 23 controls the light emission of the lighting fixture 20 (light source 22). Light emission control includes turning on the light, turning off the light, dimming, color temperature control, and light distribution control. The control unit 23 is implemented by, for example, a microcomputer, but may also be implemented by a processor or a dedicated circuit. The functions of the control unit 23 are realized by the execution of a computer program (software) stored in the storage unit 24 by the hardware, such as the microcomputer or processor that constitutes the control unit 23.

[0021] The memory unit 24 is a storage device that stores various information necessary for the control unit 23 to perform light emission control, such as computer programs executed by the control unit 23. The memory unit 24 is implemented, for example, by a semiconductor memory.

[0022] The lighting control device 30 is a lighting control device with an integrated motion sensor 31. The lighting control device 30 is installed on the ceiling or wall of the indoor space 60 and controls the lighting fixtures 20 when it detects a person. The lighting control device 30 comprises a motion sensor 31, a wireless communication unit 32, a control unit 33, and a storage unit 34.

[0023] The motion sensor 31 detects a person located in the indoor space 60. The motion sensor 31 may be implemented by, for example, a pyroelectric sensor (infrared sensor) that detects infrared radiation emitted from a person's body. The motion sensor 31 may also be implemented by an image sensor (camera) that captures an image of the indoor space 60.

[0024] The wireless communication unit 32 is a wireless communication circuit for the lighting control device 30 to communicate wirelessly (more specifically, via radio waves) with multiple lighting fixtures 20. Specifically, the wireless communication unit 32 communicates wirelessly according to a communication standard such as BLE (Bluetooth® Low Energy) or Bluetooth® mesh, but is not particularly limited to any communication standard.

[0025] The control unit 33 performs information processing to control the lighting fixture 20 when a person is detected by the motion sensor 31. The control unit 33 is implemented by, for example, a microcomputer, but may also be implemented by a processor or a dedicated circuit. The functions of the control unit 33 are realized by the execution of a computer program (software) stored in the storage unit 34 by the hardware, such as the microcomputer or processor that constitutes the control unit 33.

[0026] The memory unit 34 is a storage device that stores various types of information used by the control unit 33, such as computer programs executed by the control unit 33. The memory unit 34 is implemented, for example, by a semiconductor memory.

[0027] The relay device 40 unicasts a second notification signal, obtained from a first notification signal received from each of the multiple lighting control devices 30, to each of the multiple lighting fixtures 20 at predetermined time intervals. The first notification signal is a notification signal for each of the multiple lighting control devices 30 to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should transition at this time. The second notification signal is a notification signal for the multiple lighting fixtures 20 to notify the target dimming state to which they should transition at this time. Details of the transmission method for the first and second notification signals will be described later. The relay device 40 may be any communication node belonging to the wireless mesh network, and may be a lighting fixture, a lighting control device, or other device such as a scheduler. The relay device 40 may also be a communication device dedicated to relaying notification signals. Although not shown in Figure 1, the relay device 40 includes at least a wireless communication unit, a control unit, and a storage unit.

[0028] The management device 50 periodically transmits synchronization signals to the multiple lighting fixtures 20, multiple lighting control devices 30, and relay device 40 at predetermined time intervals to synchronize the time of the multiple lighting fixtures 20, multiple lighting control devices 30, and relay device 40. The management device 50 is, for example, a scheduler that controls the multiple lighting fixtures 20 according to a pre-set schedule, but it may be any other device. Although not shown in Figure 1, the management device 50 comprises at least a wireless communication unit, a control unit, and a storage unit.

[0029] Multiple lighting fixtures 20, lighting control devices 30, relay devices 40, and management devices 50 constitute a wireless mesh network. Figure 3 is a conceptual diagram of the wireless mesh network. In Figure 3, each circle corresponds to a single communication node (one lighting fixture 20, one lighting control device 30, one relay device 40, or one management device 50), and the dashed lines connecting the circles indicate the communication path. In the wireless mesh network, various types of information, such as control signals, are transmitted, for example, using a routing method. Specifically, when information is transmitted from the first communication node to the second communication node, the information is relayed by one or more other communication nodes as needed along the path shown by the dashed lines in Figure 3. Note that in the wireless mesh network, information may also be transmitted using other methods such as flooding.

[0030] [Zone-based dimming operation] In the lighting control system 10, the lighting control device 30, triggered by the detection of a person in the vicinity of the lighting control device 30 by the motion sensor 31, executes control to make multiple lighting fixtures 20 in a first dimming state emit light in a second dimming state that is brighter than the first dimming state. The first dimming state is, for example, the off state (dimming rate 0%), but it may also be a state with a dimming rate of 20%. The second dimming state is, for example, a state with a dimming rate of 100%, but it may also be a state with a dimming rate of 80%.

[0031] At this time, the control unit 33 of the lighting control device 30 transmits a control signal to each of the multiple lighting fixtures 20 via a wireless mesh network, for example, thereby sequentially transitioning each of the multiple lighting fixtures 20 from the first dimming state to the second dimming state.

[0032] Here, each of the multiple lighting control devices 30 and the multiple lighting fixtures 20 has a zone (an example of a group) pre-configured. For example, the same zone is configured for one lighting control device 30 and one or more lighting fixtures 20 that are installed relatively close to each other. In the following, the zones will be distinguished by numbers, such as Zone 1, Zone 2, and so on.

[0033] When a person is detected by the lighting control device 30 in which Zone 1 is set, only the lighting fixtures 20 in which Zone 1 is set will selectively transition from the first dimming state to the second dimming state. In other words, the lighting fixtures 20 are dimmed on a zone-by-zone basis. Below, an example of the zone-based dimming operation of such a lighting control system 10 will be described. Figure 4 is an example of a sequence diagram of the zone-based dimming operation of the lighting control system 10.

[0034] The motion sensor 31 of the lighting control device 30, which is set to Zone 1, detects that there is a person in the vicinity of the lighting control device 30 (S11). When the motion sensor 31 detects a person, the control unit 33 transmits a control signal via wireless mesh network to each of the multiple lighting fixtures 20 using the wireless communication unit 32 (S12). In this control signal, Zone 1 is specified as zone identification information (an example of group identification information).

[0035] When a lighting fixture 20 among the multiple lighting fixtures 20 that has Zone 1 set receives a control signal, it determines that the zone indicated by the zone identification information included in the control signal matches the zone set for itself (S13), and transitions from the first dimming state to the second dimming state according to the control signal (S14).

[0036] On the other hand, if a lighting fixture 20 among the multiple lighting fixtures 20 is set to a zone different from zone 1 (such as zone 2), when it receives a control signal, it determines that the zone indicated by the zone identification information included in the control signal does not match the zone set for itself (S15), and maintains the first dimming state without following the control signal (S16).

[0037] Furthermore, lighting control devices 30 that have zones other than Zone 1, such as Zone 2, set also perform the same processing as in steps S11 and S12. That is, when each of the multiple lighting control devices 30 detects a person with its own motion sensor 31, it unicasts a control signal to each of the multiple lighting fixtures 20 that belong to the zone it controls, in order to control the dimming of those fixtures 20. When each of the multiple lighting fixtures 20 receives the control signal, it transitions to the second dimming state specified by the control signal, provided that the zone identification information contained in the received control signal indicates the zone to which it belongs.

[0038] As explained above, the lighting control system 10 senses the presence or absence of people in each zone, and when a person is detected in a certain zone, it can adjust the brightness of the lighting fixtures 20 installed in that zone.

[0039] [Example of notification operation for target dimming state] However, when the control signal is transmitted in step S12 above, there are cases in which the lighting fixture 20, which should have transitioned to the second dimming state, does not transition to the second dimming state. Specifically, this can occur when the power to the lighting fixture 20 is off, or when the communication status of the lighting fixture 20 is poor.

[0040] In order to transition such lighting fixtures 20 to a second dimming state, each of the multiple lighting control devices 30 manages the target dimming state (dimming rate) to which the lighting fixtures 20 belonging to its controlled zone should transition at that moment, and transmits a first notification signal to each of the multiple lighting fixtures 20 via unicast at predetermined time intervals, such as one minute (periodically). As a result, a lighting fixture 20 that receives the first notification signal can transition to the same dimming state as the other lighting fixtures 20 belonging to the same zone from the time it receives the first notification signal.

[0041] Figure 5 shows an example (comparative example) of a method for transmitting the first notification signal. Figure 5 shows the transmission method when each of the three zones 1 to 3 has one lighting control device 30 and three lighting fixtures 20.

[0042] As a method for transmitting the first notification signal, a method of unicast transmission through a wireless mesh network to each of the plurality of lighting fixtures 20 can be considered, similar to the method for transmitting the control signal in step S12 described above.

[0043] In the case of FIG. 5, the lighting control device 30 set in zone 1 unicast-transmits a first notification signal (in other words, a first notification signal indicating the target dimming state of zone 1) for notifying the target dimming state of zone 1 to each of the nine lighting fixtures 20. Similarly, the lighting control device 30 set in zone 2 unicast-transmits a first notification signal for notifying the target dimming state of zone 2 to each of the nine lighting fixtures 20, and the lighting control device 30 set in zone 3 unicast-transmits a first notification signal for notifying the target dimming state of zone 3 to each of the nine lighting fixtures 20. As a result, the unicast transmission of the first notification signal occurs a total of 27 times.

[0044] [Example of the operation for notifying the target dimming state] In order to reduce the number of unicast transmissions of the first notification signal, the inventors have found a configuration in which the relay device 40 aggregates the first notification signal and unicast-transmits a second notification signal obtained by aggregating the first notification signal to each of the plurality of lighting fixtures 20 (nine lighting fixtures 20). FIG. 6 is a diagram showing an example (embodiment) of the method for transmitting the first notification signal.

[0045] In the case of FIG. 6, each of the three lighting control devices 30 unicast-transmits the first notification signal to the relay device 40, and the relay device 40 unicast-transmits a second notification signal obtained by aggregating three types of first notification signals corresponding to the three lighting control devices 30 to each of the nine lighting fixtures 20. In other words, the relay device 40 unicast-transmits, at a predetermined time interval, a second notification signal obtained from the first notification signals received from each of the three lighting control devices 30 and indicating the target dimming state to which the plurality of lighting fixtures 20 should transition at the current time, to each of the plurality of lighting fixtures 20. The second notification signal is a notification signal for notifying the target dimming state of each of zones 1 to 3, and is a notification signal indicating the target dimming state of each of zones 1 to 3.

[0046] As a result, when each of the plurality of lighting fixtures 20 receives the second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state, it can transition to the target dimming state.

[0047] According to the transmission method of FIG. 6, the unicast transmission of the first notification signal occurs only 3 times, and the unicast transmission of the second notification signal occurs only 9 times, reducing the number of unicast transmissions of the notification signal from 27 times in the transmission method of FIG. 5 to 12 times. Therefore, the lighting control system 10 can alleviate the congestion of communication in the wireless mesh network.

[0048] Regarding the transmission timings of the first notification signal and the second notification signal in the transmission method of FIG. 6, there is no particular limitation. As an example, the case where three lighting control devices 30 transmit the first notification signal at a time interval T and the relay device 40 also transmits the second notification signal at the time interval T will be specifically described. The lighting control device 30 set in zone 1 transmits the first notification signal at time t0, the lighting control device 30 set in zone 2 transmits the first notification signal at time t0 + Δt, and the lighting control device 30 set in zone 3 transmits the first notification signal at time t0 + 2×Δt. That is, the first timings at which each of the plurality of lighting control devices 30 unicast transmits the first notification signal to the relay device 40 are different from each other.

[0049] The relay device 40, for example, transmits the second notification signal at time t0 + 3×Δt. That is, the second timing at which the relay device 40 unicast transmits the second notification signal to the plurality of lighting fixtures 20 is different from the first timing. Δt is a time length shorter than T / 3, and when T is 1 minute, Δt is 15 seconds or the like.

[0050] Note that the three lighting control devices 30 and the relay device 40 are time synchronized by a synchronization signal provided by the management device 50. The synchronization signal is distributed (provided) at, for example, a time interval T, and time t0 is the timing at which the synchronization signal is received.

[0051] In this way, if the transmission timings of the first notification signal and the second notification signal are set so as not to overlap, the lighting control system 10 can suppress communication congestion.

[0052] Although Figure 6 shows the relay device 40 as belonging to Zone 2, the zone to which the relay device 40 belongs is not particularly limited. Furthermore, the relay device 40 does not have to belong to any zone.

[0053] [Supplement 1] First, let's add a supplement regarding the case where the relay device 40 is one of the multiple lighting fixtures 20. The lighting fixture 20 corresponding to the relay device 40 is referred to as the first lighting fixture, and the lighting fixture 20 not corresponding to the relay device 40 is referred to as the second lighting fixture. In this case, each of the multiple lighting control devices 30 transmits a first notification signal to the first lighting fixture via unicast at predetermined time intervals. The first lighting fixture transmits a second notification signal, obtained from the first notification signals received from each of the multiple lighting control devices 30, via unicast at predetermined time intervals, which is a second notification signal for notifying the target dimming state that the second lighting fixture should transition to at this time. When the second lighting fixture receives the second notification signal, if the target dimming state of the group to which it belongs, indicated by the received second notification signal, is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs, indicated by the received second notification signal.

[0054] Next, we will provide supplementary information regarding the case where the relay device 40 is one of the multiple lighting control devices 30. The lighting control device 30 corresponding to the relay device 40 is designated as the second lighting control device, and the lighting control device 30 not corresponding to the relay device 40 is designated as the first lighting control device. In this case, the first lighting control device unicasts a first notification signal to the second lighting control device at predetermined time intervals. The second lighting control device unicasts a second notification signal to each of the multiple lighting fixtures 20 at predetermined time intervals. This second notification signal includes the content of the first notification signal received from the first lighting control device, in addition to a notification signal to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should transition at the present time.

[0055] [Supplement 2] Note that the lighting fixture 20 that has transitioned to the second dimming state returns to the first dimming state after the control hold time has elapsed. The control hold time is defined, for example, in the control signal. In other words, the control signal includes information indicating the control hold time. However, the control hold time may be stored (registered) in advance in the memory unit 24 of multiple lighting fixtures 20 during initial setup, etc., and it is not essential that the control hold time is defined in the control signal.

[0056] Furthermore, if the control hold time is specified in the control signal, the user only needs to change the settings on the lighting control device 30 when changing the control hold time, which has the advantage of being easier to change compared to a configuration where the settings of each of the multiple lighting fixtures 20 must be changed individually. If the control hold time is pre-stored in the memory units 24 of the multiple lighting fixtures 20, the information indicating the control hold time can be omitted in the control signal, which has the advantage of reducing the amount of information in the control signal.

[0057] Furthermore, the dimming rate in the second dimming state is defined in the control signal. In other words, the control signal includes information that indicates the dimming rate. However, the dimming rate in the second dimming state may be pre-stored (registered) in the memory units 24 of multiple lighting fixtures 20 during initial setup, and it is not essential that the dimming rate in the second dimming state is defined in the control signal.

[0058] Furthermore, if the dimming rate in the second dimming state is defined in the control signal, the user only needs to change the settings on the lighting control device 30 when changing the dimming rate, which has the advantage of being easier to change settings compared to a configuration where the settings of each of the multiple lighting fixtures 20 must be changed. If the dimming rates of the second dimming state are pre-stored in the memory units 24 of the multiple lighting fixtures 20, the information indicating the dimming rate can be omitted in the control signal, which has the advantage of reducing the amount of information in the first and second control signals.

[0059] [Modification] In the above embodiment, the sensor provided by the lighting control device 30 was described as a human presence sensor 31. However, the lighting control device 30 may be equipped with any sensor capable of detecting various state changes in the vicinity of the lighting control device 30. For example, the lighting control device 30 may be equipped with a temperature sensor, a humidity sensor, a carbon dioxide concentration sensor, a PM (Particulate Matter) sensor, or an odor sensor. The present invention is useful, for example, in cases where multiple wireless communication devices are controlled collectively when the measured value (sensing result) of a sensor satisfies predetermined conditions.

[0060] [Effects, etc.] Below, examples of inventions obtained from the disclosures of this specification will be given, and the effects, etc. obtained from said inventions will be explained.

[0061] Invention 1 comprises a plurality of lighting fixtures 20, a plurality of lighting control devices 30, and a relay device 40. The plurality of lighting fixtures 20, the plurality of lighting control devices 30, and the relay device 40 constitute a wireless mesh network. When each of the plurality of lighting control devices 30 detects a change in state using its own sensor, it unicasts a control signal to each of the plurality of lighting fixtures 20 belonging to its controlled group for dimming control. It also unicasts a first notification signal to the relay device 40 at predetermined time intervals to notify the lighting fixture 20 belonging to its controlled group of the target dimming state to which it should currently transition. The relay device 40 then controls each of the plurality of lighting control devices 30. The lighting control system 10 unicasts a second notification signal, obtained from a first notification signal received from a plurality of lighting fixtures 20, to each of the plurality of lighting fixtures 20 at predetermined time intervals, which notifies the target dimming state to which each of the plurality of lighting fixtures 20 should transition at the present time. Each of the plurality of lighting fixtures 20, upon receiving a control signal, transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. Upon receiving a second notification signal, if the target dimming state of the group to which it belongs, indicated by the received second notification signal, is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs, indicated by the received second notification signal. The human presence sensor 31 in the above embodiment is an example of a sensor, and the zone in the above embodiment is an example of a group.

[0062] In such a lighting control system 10, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the relay device 40 aggregates the first notification signals and unicasts a second notification signal to each of the multiple lighting fixtures 20. Therefore, the lighting control system 10 can alleviate communication congestion.

[0063] Invention 2 is a lighting control system 10 of Invention 1, wherein a plurality of lighting control devices 30 synchronize their time based on synchronization signals provided by a management device 50, and the first timing at which each of the plurality of lighting control devices 30 unicasts a first notification signal to a relay device 40 is different from one another.

[0064] In such a lighting control system 10, multiple lighting control devices 30 transmit a first notification signal to a relay device 40 via unicast at different first timings. Therefore, the lighting control system 10 can mitigate communication congestion.

[0065] Invention 3 is a lighting control system 10 of Invention 2, wherein a plurality of lighting control devices 30 and a relay device 40 synchronize their time based on a synchronization signal provided by a management device 50, and the second timing at which the relay device 40 unicasts a second notification signal to a plurality of lighting fixtures 20 is different from the first timing.

[0066] In such a lighting control system 10, the relay device 40 unicasts a second notification signal to the relay device 40 at a second timing that is different from the first timing. Therefore, the lighting control system 10 can alleviate communication congestion.

[0067] Invention 4 is a lighting control system 10 according to any one of Inventions 1 to 3, wherein the relay device 40 is a scheduler that controls at least some of the multiple lighting fixtures according to a pre-set schedule.

[0068] In such a lighting control system 10, the scheduler can be used as a relay device 40.

[0069] Invention 5 comprises a plurality of lighting fixtures 20 and a plurality of lighting control devices 30, the plurality of lighting fixtures 20 and the plurality of lighting control devices 30 forming a wireless mesh network, and each of the plurality of lighting control devices 30, when it detects a change in state using its own sensor, unicasts a control signal to each of the plurality of lighting fixtures 20 belonging to its controlled group for dimming control, and unicasts a first notification signal to a first lighting fixture among the plurality of lighting fixtures 20 at predetermined time intervals to notify the lighting fixture 20 belonging to its controlled group of the target dimming state to which it should currently transition, and the first lighting fixture receives the first notification signal from each of the plurality of lighting control devices 30. This lighting control system unicasts a second notification signal obtained from a first notification signal to a second lighting fixture 20 at predetermined time intervals, which notifies the second lighting fixture 20 of the target dimming state to which it should currently transition. Each of the multiple lighting fixtures 20 transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. The second lighting fixture transitions to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

[0070] In such a lighting control system 10, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the first lighting fixture unicasts a second notification signal, which is an aggregate of the first notification signals, to the second lighting fixture. Therefore, the lighting control system 10 can alleviate communication congestion.

[0071] Invention 6 comprises a plurality of lighting fixtures 20 and a plurality of lighting control devices 30, the plurality of lighting fixtures 20 and the plurality of lighting control devices 30 constitute a wireless mesh network, and each of the plurality of lighting control devices 30, when it detects a change in state using its own sensor, unicasts a control signal to each of the plurality of lighting fixtures 20 belonging to its controlled group for dimming control, the first lighting control device of the plurality of lighting control devices 30 unicasts a first notification signal to the second lighting control device of the plurality of lighting control devices 30 at predetermined time intervals to notify the lighting fixture 20 belonging to its controlled group of the target dimming state to which it should currently transition, and the second lighting control device unicasts a first notification signal to the second lighting control device of the plurality of lighting control devices 30 at predetermined time intervals to notify the lighting fixture 20 belonging to its controlled group of the target dimming state to which it should currently transition, The lighting control system 10 unicasts to each of the multiple lighting fixtures 20 at predetermined time intervals, a second notification signal which includes the content of the first notification signal received from the first lighting control device, in order to notify each of the multiple lighting fixtures 20 of the target dimming state to which they should transition at a given time, and which notifies each of the multiple lighting fixtures 20 of the target dimming state to which they should transition at the present time. When each of the multiple lighting fixtures 20 receives a control signal, it transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. When it receives a second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state, it transitions to the current target dimming state of the group to which it belongs indicated by the received second notification signal.

[0072] In such a lighting control system 10, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the second lighting control device unicasts a second notification signal, which is an aggregate of the first notification signals, to each of the multiple lighting fixtures 20. Therefore, the lighting control system 10 can alleviate communication congestion.

[0073] Invention 7 is a lighting control method performed by a lighting control system 10 comprising a plurality of lighting fixtures 20, a plurality of lighting control devices 30, and a relay device 40, wherein the plurality of lighting fixtures 20, a plurality of lighting control devices 30, and a relay device 40 constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices 30, when it detects a change in state using its own sensor, unicasting a control signal to each of the plurality of lighting fixtures 20 to control the dimming of the lighting fixtures 20 belonging to its group of controlled fixtures 20; each of the plurality of lighting control devices 30, unicasting a first notification signal to the relay device 40 at predetermined time intervals to notify the target dimming state to which the lighting fixtures 20 belonging to its group of controlled fixtures should transition at this time; and the relay device 40 The lighting control method includes the steps of: unicasting a second notification signal obtained from a first notification signal received from each of the multiple lighting control devices 30, which notifies each of the multiple lighting fixtures 20 of the target dimming state to which the multiple lighting fixtures 20 should transition at the present time, to each of the multiple lighting fixtures 20 at predetermined time intervals; when each of the multiple lighting fixtures 20 receives a control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and when each of the multiple lighting fixtures 20 receives a second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state.

[0074] In this lighting control method, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the relay device 40 aggregates the first notification signals and unicasts a second notification signal to each of the multiple lighting fixtures 20. Therefore, the lighting control method can alleviate communication congestion.

[0075] Invention 8 is a lighting control method performed by a lighting control system 10 comprising a plurality of lighting fixtures 20 and a plurality of lighting control devices 30, wherein the plurality of lighting fixtures 20 and the plurality of lighting control devices 30 constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices 30, when it detects a change in state using a sensor it has, unicasting a control signal to each of the plurality of lighting fixtures 20 to control the dimming of the lighting fixtures 20 belonging to its group of controlled lighting fixtures 20; each of the plurality of lighting control devices 30, at predetermined time intervals, unicasting a first notification signal to a first lighting fixture among the plurality of lighting fixtures 20 to notify the target dimming state to which the lighting fixtures 20 belonging to its group of controlled lighting fixtures should transition at this time; and the first lighting fixture However, the lighting control method includes the steps of: unicasting a second notification signal obtained from a first notification signal received from each of the multiple lighting control devices 30, which notifies the second lighting fixture among the multiple lighting fixtures 20 of the target dimming state to which the second lighting fixture should transition at the present time, to the second lighting fixture at predetermined time intervals; when each of the multiple lighting fixtures 20 receives a control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and when the second lighting fixture receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs indicated by the received second notification signal is different from its current dimming state.

[0076] In this lighting control method, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the first lighting fixture unicasts a second notification signal, which is an aggregate of the first notification signals, to the second lighting fixture. Therefore, the lighting control method can alleviate communication congestion.

[0077] Invention 9 is a lighting control method performed by a lighting control system 10 comprising a plurality of lighting fixtures 20 and a plurality of lighting control devices 30, wherein the plurality of lighting fixtures 20 and the plurality of lighting control devices 30 constitute a wireless mesh network, and the lighting control method comprises the steps of: each of the plurality of lighting control devices 30, when it detects a change in state by a sensor it has, unicasting a control signal to each of the plurality of lighting fixtures 20 to control the dimming of the lighting fixtures 20 belonging to its group of controlled fixtures 20; the first lighting control device of the plurality of lighting control devices 30 unicasting a first notification signal to a second lighting control device of the plurality of lighting control devices 30 at predetermined time intervals to notify the target dimming state to which the lighting fixtures 20 belonging to its group of controlled fixtures should transition at this time; and the second lighting control device, belonging to its group of controlled fixtures The lighting control method includes the steps of: unicasting a second notification signal to each of the multiple lighting fixtures 20 at predetermined time intervals, the second notification signal containing the contents of the first notification signal received from the first lighting control device, which is a notification signal for notifying each of the multiple lighting fixtures 20 of the target dimming state to which each of the multiple lighting fixtures 20 should transition at the present time; when each of the multiple lighting fixtures 20 receives a control signal, transitioning to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs; and when each of the multiple lighting fixtures 20 receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

[0078] In this lighting control method, instead of each of the multiple lighting control devices 30 unicasting a first notification signal to each of the multiple lighting fixtures 20, the second lighting control device unicasts a second notification signal, which is an aggregate of the first notification signals, to each of the multiple lighting fixtures 20. Therefore, the lighting control method can alleviate communication congestion.

[0079] Invention 10 is a program for causing a lighting control system 10 to execute any of the lighting control methods of Inventions 7 to 9.

[0080] According to such a program, the lighting control system 10 can mitigate communication congestion.

[0081] (Other Embodiments) Although embodiments have been described above, the present invention is not limited to the embodiments described above.

[0082] For example, in the above embodiment, a process executed by a specific processing unit may be executed by another processing unit. Furthermore, the order of multiple processes may be changed, or multiple processes may be executed in parallel.

[0083] Furthermore, in the above embodiment, each component may be realized by executing a software program suitable for each component. Each component may also be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0084] Furthermore, each component may be implemented by hardware. For example, each component may be a circuit (or integrated circuit). These circuits may form a single circuit as a whole, or they may be separate circuits. Also, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0085] Furthermore, general or specific embodiments of the present invention may be implemented as a system, apparatus, method, integrated circuit, computer program, or recording medium such as a computer-readable CD-ROM. Alternatively, they may be implemented as any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

[0086] For example, the present invention may be implemented as a lighting control system, lighting fixture, lighting control device, or relay device as described above, or as a method executed by a computer such as a lighting control system, lighting fixture, lighting control device, or relay device. The present invention may be implemented as a program (computer program product) for causing a computer to execute such a method, or as a computer-readable non-temporary recording medium on which such a program is recorded.

[0087] Furthermore, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art could conceive, or forms realized by arbitrarily combining the components and functions of each embodiment without departing from the spirit of the present invention.

[0088] 10 Lighting control system 20 Lighting fixtures 21, 32 Wireless communication unit 22 Light source 23, 33 Control unit 24, 34 Memory unit 30 Lighting control device 31 Motion sensor 40 Relay device 50 Management device 60 Indoor space

Claims

1. The system comprises a plurality of lighting fixtures, a plurality of lighting control devices, and a relay device, wherein the plurality of lighting fixtures, the plurality of lighting control devices, and the relay device constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state using a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group, and transmits a first notification signal to the relay device at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should currently transition, and the relay device transmits a second notification signal obtained from the first notification signal received from each of the plurality of lighting control devices, which notifies the lighting fixtures of the target dimming state to which they should currently transition, at predetermined time intervals, and each of the plurality of lighting fixtures, upon receiving the control signal, transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. A lighting control system that, upon receiving the second notification signal, transitions to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs differs from its current dimming state.

2. The lighting control system according to claim 1, wherein the plurality of lighting control devices synchronize their time based on a synchronization signal provided by a management device, and the first timing at which each of the plurality of lighting control devices unicasts the first notification signal to the relay device is different from that of the others.

3. The lighting control system according to claim 2, wherein the plurality of lighting control devices and the relay device synchronize their time based on the synchronization signal provided by the management device, and the second timing at which the relay device unicasts the second notification signal to the plurality of lighting fixtures is different from the first timing.

4. The lighting control system according to claim 1, wherein the relay device is a scheduler that controls at least some of the plurality of lighting fixtures according to a pre-set schedule.

5. The system comprises a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state using a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group, and transmits a first notification signal to a first lighting fixture among the plurality of lighting fixtures at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should currently transition, and the first lighting fixture transmits a second notification signal to the second lighting fixture at predetermined time intervals, which is obtained from the first notification signal received from each of the plurality of lighting control devices, to the second lighting fixture among the plurality of lighting fixtures for notifying the target dimming state to which it should currently transition, and each of the plurality of lighting fixtures, upon receiving the control signal, transitions to the dimming state specified by the control signal, provided that the group identification information included in the received control signal indicates the group to which it belongs. The second lighting fixture is a lighting control system that, upon receiving the second notification signal, transitions to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

6. The system comprises a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and each of the plurality of lighting control devices, when it detects a change in state using a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its controlled group among the plurality of lighting fixtures, via unicast, the first lighting control device among the plurality of lighting control devices transmits a first notification signal to a second lighting control device among the plurality of lighting control devices at predetermined time intervals to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should currently transition, via unicast, the second lighting control device transmits a second notification signal to each of the plurality of lighting fixtures at predetermined time intervals, which includes the content of the first notification signal received from the first lighting control device in addition to the notification signal to notify the lighting fixtures belonging to its controlled group of the target dimming state to which they should currently transition, via unicast, the multiple lighting fixtures, A lighting control system that, upon receiving the aforementioned control signal, transitions to the dimming state specified by the control signal, provided that the group identification information contained in the received control signal indicates the group to which it belongs; and upon receiving the second notification signal, transitions to the current target dimming state of the group to which it belongs, provided that the target dimming state of the group to which it belongs, as indicated by the received second notification signal, differs from its current dimming state.

7. A lighting control method performed by a lighting control system comprising a plurality of lighting fixtures, a plurality of lighting control devices, and a relay device, wherein the plurality of lighting fixtures, the plurality of lighting control devices, and the relay device constitute a wireless mesh network, and the lighting control method comprises: a step in which each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures from among the plurality of lighting fixtures, via unicast; a step in which each of the plurality of lighting control devices, via unicast, transmits a first notification signal to the relay device at predetermined time intervals to notify the target dimming state to which the lighting fixtures belonging to its group of controlled fixtures should transition at the present time; and a step in which the relay device, via unicast, transmits a second notification signal obtained from the first notification signals received from each of the plurality of lighting control devices, which notifies the target dimming state to which the plurality of lighting fixtures should transition at the present time, via unicast, to each of the plurality of lighting fixtures at predetermined time intervals. A lighting control method comprising: when each of the plurality of lighting fixtures receives the control signal, transitioning to a dimming state specified by the control signal, provided that the group identification information contained in the received control signal indicates the group to which it belongs; and when each of the plurality of lighting fixtures receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

8. A lighting control method performed by a lighting control system comprising a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and the lighting control method comprises: a step in which each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures from among the plurality of lighting fixtures; a step in which each of the plurality of lighting control devices, at predetermined time intervals, transmits a first notification signal to a first lighting fixture among the plurality of lighting fixtures at a predetermined time interval to notify the lighting fixtures belonging to its group of controlled fixtures of the target dimming state to which they should currently transition; and a step in which the first lighting fixture, at predetermined time intervals, transmits a second notification signal obtained from the first notification signals received from each of the plurality of lighting control devices, at predetermined time intervals, to the second lighting fixture, for notifying the second lighting fixture among the plurality of lighting fixtures of the target dimming state to which it should currently transition. A lighting control method comprising: when each of the plurality of lighting fixtures receives the control signal, transitioning to a dimming state specified by the control signal, provided that the group identification information contained in the received control signal indicates the group to which it belongs; and when the second lighting fixture receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

9. A lighting control method performed by a lighting control system comprising a plurality of lighting fixtures and a plurality of lighting control devices, wherein the plurality of lighting fixtures and the plurality of lighting control devices constitute a wireless mesh network, and the lighting control method comprises: a step in which each of the plurality of lighting control devices, when it detects a change in state by a sensor it has, transmits a control signal to each of the plurality of lighting fixtures for dimming control of the lighting fixtures belonging to its group of controlled fixtures, via unicast; a step in which a first lighting control device among the plurality of lighting control devices transmits a first notification signal to a second lighting control device among the plurality of lighting control devices at predetermined time intervals to notify the lighting fixtures belonging to its group of controlled fixtures of the target dimming state to which they should currently transition; and a step in which the second lighting control device transmits a second notification signal to each of the plurality of lighting fixtures at predetermined time intervals, which includes the content of the first notification signal received from the first lighting control device in the notification signal for notifying the lighting fixtures belonging to its group of controlled fixtures of the target dimming state to which they should currently transition, via unicast; A lighting control method comprising: when each of the plurality of lighting fixtures receives the control signal, transitioning to a dimming state specified by the control signal, provided that the group identification information contained in the received control signal indicates the group to which it belongs; and when each of the plurality of lighting fixtures receives the second notification signal, transitioning to the current target dimming state of the group to which it belongs, as indicated by the received second notification signal, if the target dimming state of the group to which it belongs, as indicated by the received second notification signal, is different from its current dimming state.

10. A program for causing the lighting control system to execute the lighting control method according to any one of claims 7 to 9.

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