Design and Analysis of Natural Light Illumination System by Innovative Optical Design Method and Hybrid Taguchi-Simulated Annealing Algorithm

• Main Authors: Shih-Min Chao, 趙世民
• Other Authors: Allen Jong-Woei Whang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/ck289e

博士 === 國立臺灣科技大學 === 電子工程系 === 102 === ABSTRACT Regarding to the energy-saving and carbon dioxide reduction, the green energy has been gaining popularity in recent years. For saving energy and healthy lighting, there are many researches to focus on sunlight system without opto-electronic conversion, ex : HIMAWARI, SOLUX and Natural Light Illumination System (NLIS). Among on those technologies, NLIS can be used in construction and gather nature light for indoor illumination. There are three subsystems of NLIS, collecting, transmitting and emitting subsystem. Natural light illumination system (NLIS) with sunlight can be separated into collecting, transmitting, and emitting three subsystems. Regarding to collecting subsystem, prismatic elements play a key role in the natural light illumination system for collecting and guiding sunlight. The prismatic elements are named as “light bricks” and tile on the outsides of buildings for indoor illumination. In this paper, we present an innovative prismatic structures design to highly increase the efficiency compared to conventional light bricks. By the mathematical analysis, we design two prismatic elements as “Main Light Bricks” and “Support Light Bricks”. By assembling the two light bricks as a basic unit, the sunlight will be compressed to transmit and the system still keep high efficiency after guiding over ten cascadable units. Regarding to the cascadable characteristic, the innovative New Light Bricks not only increase the efficiency but reduce the numbers of output ports compared to conventional light bricks. NLIS can save 80% of the energy compared to traditional lighting. However, there is a size mismatch problem happened between conventional collecting and transmitting subsystems. For reducing the thickness and weight of the system, the dimensions of collecting subsystem have to design as thinner as possible. In opposite, the transmitting components are designed larger size for gathering higher transmission efficiency as possible. For solving the size mismatch and coupling problem, we proposed an innovative optical tapered coupler with the prism structure applied between collecting and transmitting subsystems of NLIS. The new optical coupler can easy to connect these two subsystems and increase the modulization capability of NLIS. In this research, we analyzed the mathematical model and coupling efficiency. Furthermore, we also analyzed the transmission efficiency of completed system including collecting, Tapered Prism Coupler (TPC) and transmitting subsystems. Compared to conventional NLIS coupler, like fiber, the innovative TPC can increase 1.4 times efficiency than conventional one based on whole system (Including light Brick, coupler and 2m light pipes). The TPC not only increases efficiency but also be easy to assemble these two subsystems and mass production based on modular design concept. Regarding to the innovative TPC and NLIS, we can provide steady illumination in indoor space for healthy illumination and energy saving. For design the optical lens of emitting subsystem, we proposes a new method for optimizing the total internal reflection (TIR) Lens and indoor illumination lens by using a hybrid Taguchi-Simulated Annealing algorithm. Regarding to different collecting and transmitting design, we have to re-designed the emitting components due to the variance of output light distribution. Therefore, it is necessary to re-design by optimization program. The conventional Simulated Annealing (SA) algorithm is a method for solving the global optimization problem and also being used in non-imaging system in recent years. However, the success of the SA depends heavily on annealing schedule and initial parameters setting. In this research, we incorporated the steady Taguchi method into SA algorithm and applied to TIR lens and indoor illumination lens successfully. The new Hybrid Taguchi-Simulated Annealing algorithm shows the more precise searching results and lower initial parameters dependence.