Illumination control apparatus and illumination control method

An illumination control apparatus which controls illumination of a room in which at least one lighting device having plural lighting modes and at least two occupancy sensors are installed, the illumination control apparatus comprising:

• a detection result obtainer which obtains results of detections by the at least two occupancy sensors;
• a storage storing lighting mode information indicating correspondence between (i) plural combinations of the results of the detections by the at least two occupancy sensors and (ii) the plural lighting modes of the at least one lighting device;
• and
• a controller which refers to the lighting mode information, identifies a lighting mode among the plural lighting modes that corresponds to a combination of the results of the detections by the at least two occupancy sensors obtained by the detection result obtainer, and places the at least one lighting device in the identified lighting mode, wherein
• in switching a first lighting mode to a second lighting mode when the combination of the results of the detections by the at least two occupancy sensors obtained by the detection result obtainer changes, the first lighting mode and the second lighting mode being included in the plural lighting modes, the controller:
• compares a first priority level of the first lighting mode and a second priority level of the second lighting mode, the first priority level and the second priority level being priority levels pre-assigned to the first lighting mode and the second lighting mode, respectively;
• if the second priority level is lower than the first priority level, maintains the first lighting mode for a predetermined amount of wait time, from a moment when the combination of the results of the detections changes, and subsequently switches the first lighting mode to the second lighting mode;
• and
• if the second priority level is higher than the first priority level, switches the first lighting mode to the second lighting mode at the moment when the combination of the results of the detections changes.