In this study, fuzzy control-based illumination system is proposed to handle light space by LED illumination. The illumination system is designed by using RGB(Red, Green, Blue) LED, and the RGB LED is realized by synthetic light obtained through constant electric currents. The color distribution of the synthetic light of RGB LED is measured by color sensor with 8-bit resolution, and the closed loop control is carried out by comparing between feedback value based on controller and reference value. The reference value is given by color temperature, and the fuzzy control-based illumination system is designed to solve difficulty in controlling color temperature through transformation process that the color temperature is transformed to color distribution of RGB by transformation formula.

Generally, the illumination is considered as a design factor to form the living place that affects human''s emotion and action under the general illumination space as well as intention to give light on the specific illumination space. The illumination space is designed as color temperature, and the emotional language and learning subject can be transformed into color temperature by transformation process.

Fuzzy controller based on expert''s knowledge described with the aid of control rules and membership functions is introduced as an advantage for controlling the nonlinear illumination system, and the controller has already widely being used in many industrial fields. In fuzzy controller, scaling factors are used as the control parameters of conventional PID controller. The optimized scaling factors adjusted by means of evolutionary algorithms lead to better output performance of the fuzzy controller and also more preferred fuzzy control-based illumination system. In this study, we use two kinds of evolutionary algorithms such as Genetic Algorithms(GA) and Particle Swarm Optimization(PSO) algorithm for designing the optimized fuzzy controller.