A new optimal light sensor placement method of an indoor lighting control system for improving energy performance and visual comfort

Abstract

Lighting consumes a substantial amount of energy in buildings. Therefore, the energy can be potentially reduced by implementing optimal control strategies, including an optimal light sensor placement and an intelligent control. This paper presents a new optimal light sensor placement method (OLSPM) of a lighting system in terms of numbers and positions to minimize costs (i.e., initial and energy), and simultaneously maintain the visual comfort that satisfies the standard EN12464-1 in terms of illuminance-based metrics. The optimum position of the sensors was determined based on a proposed mathematical model, which is illuminance center grid, and then, an objective function and its constraints were formulated: average dimming levels of LED luminaires, and illuminance level and uniformity, respectively. Moreover, a new dimming level of luminaires model was proposed to calculate the objective function. Particle swarm optimization (PSO) algorithm was utilized for solving the formulated problem. Finally, the optimum position of the sensors was determined based on the PSO results and the proposed illuminance deviation model. This methodology denoted OLSPM-PSO. The OLSPM-PSO was tested on two case studies: a meeting room and an office room. To evaluate the performance of the OLSPM-PSO with other methods, the OLSPM-PSO was integrated with the developed fuzzy logic controller as a control strategy. The comparative results showed the superiority of the OLSPM-PSO with provided optimum number and position of sensors, significant energy savings up to 24.5% and fully satisfied visual comfort in accordance with EN12464-1 (i.e., average illuminance level and uniformity) and confirmed its potential to be implemented for all types of rooms with higher accuracy.