Light sensor calibration and dimming sequence design in distributed lighting control systems

We consider distributed lighting control systems consisting of multiple asynchronous feedback controllers that adapt dimming of intelligent light source based on occupancy and illuminance value as measured by co-located occupancy and light sensors respectively. In an initial calibration step, the set-point at the light sensor for every controller is determined. Changes in reflectance due to factors like changes in occupancy and object characteristics modify the set-point, thus adversely affecting the illumination distribution from the lighting system. We propose a method for sensor set-point calibration and tracking and an associated lighting control algorithm. Initial calibration of set-points is achieved distributedly with light sources dimming according to a proposed sequence. We show that the proposed methods improve the illumination performance of the lighting system in event of reflectance changes.