全色固態照明控制技術研究

Polychromatic Control Technology of Solid State Lighting

湯鈞汶(Chun-en Tang)

指導教授 ： 黃秉鈞

國立臺灣大學/工學院/機械工程學研究所/博士(2008年)

https://doi.org/10.6342/NTU.2008.03287

摘要

使用紅、綠、藍(red-green-blue, RGB)發光二極體(light-emitting diode, LED)的全彩照明，亟待解決的問題是照明亮度及色彩因燈具受熱而不穩定。本研究提出一種以光度迴授及接面溫度補償為控制架構的RGB LED照明控制系統，以控制LED於白光照明的亮度及色彩。為此設計符合全光照明的RGB LED燈具，並推導其熱-電-光-色動態系統模型，瞭解燈具的動態系統關係以設計控制系統。
RGB LED燈具動態模型可分為熱、色、光三個部分的多變量系統。熱模型可由理論推導為輸入電功率對接面溫度的四階系統，經系統識別可簡化為一階正當(first-order bi-proper)系統。色、光模型由光電理論推導出電功率及接面溫度為輸入，色模型定義為色度座標的二維動態行為為輸出，光模型以亮度(光強度)響應為輸出。光、色模型因光子反應時間遠快於燈具熱效應為零階系統，並由系統識別發現是輸入功率及接面溫度的非線性模型。由各模型的物理特性從屬關係，可建立出完整的RGB LED燈具熱-電-光-色模型，能應用於系統控制。
全色照明的控制系統，將設定的亮度及相關色溫值，轉換成光度的控制指令；再利用光度迴授控制使照明亮度穩定，並量測接面溫度及光、色模型計算以求得的補償，確保色彩不變。控制演算採用PI控制器，可滿足暫態響應並消除穩態誤差及減少色彩偏差量。系統測試結果顯示，系統暫態上升時間tr = 0.88秒、穩定時間ts = 2.84秒；受溫度干擾測試的亮度誤差在0.99％，並使色彩的色度座標偏差量Δu′v′= 0.00171。因色差小於人眼感知範圍Δu′v′ < 0.0035，故設計的控制系統可用於RGB LED的全光照明。

關鍵字

發光二極體 ； 多色光源照明 ； 熱-電-光-色模型 ； 光色亮度控制 ； 系統識別 ； 接面溫度量測 ； 燈具照明設計

並列摘要

The main purpose of this research is to investigate the control technology of red-green-blue (RGB) light emitting-diode (LED) in order to stabilize luminance and color of lighting. In addition, the well control performance can be provided by knowing of thermal-electric-luminous-chromatic dynamics of RGB LED luminaire.
The dynamic model of RGB LED luminaire is a Multi-Input Multi-Output system, and can be divided into three parts as thermal, chromatic and luminous model. Thermal model is derived as fourth-order system, and can be simplified as first-order bi-proper system by using system identification technique. Chromatic and luminous model are zero-th order system due to fast response of photon. The system identification shows that both models are non-linear systems of input power and junction temperature. By knowing the complete thermal-electric-luminous-chromatic model, the control system can thus design by using luminous feedback and junction temperature compensation. In this study, the PI control can satisfy transient specification and reduce luminous steady-state error and color difference. The experimental results showed rise time tr = 0.88s and settling time ts = 2.84s. It also indicated luminous error 0.99％ and color difference Δu′v′= 0.00171 under 15W thermal disturbance. The results prove that the control system can improve RGB LED lighting performance.

並列關鍵字

light emitting-diode ； polychromatic lighting ； Thermal-electric-luminous- chromatic model ； chromatic and luminous control ； system identification ； junction temperature measurement ； luminaire and lighting design.

參考文獻

[66] Datasheet EHP-A08B UT01-P01, High Power LED – 1W, Everlight Electronic Co, website: “http://www.everlight.com/”

[68] Datasheet EHP-B02, RGGB High Power LED – 4W, Everlight Electronic Co, website:http://www.everlight.com/.

[1] M.G. Craford, LED’s challenge the incandescents, IEEE circuits and devices Mag. 8 (1992) 24-29.

[2] D.A. Steigerwald, J.C. Bhat, D. Collins, R.M. Fletcher, M.O. Holcomb, Illumination with solid state lighting technology, IEEE J. Selected Topics in Quatum Electronics 8 (3) (2002) 310-320.

[3] J. Liberman, Light–Medicine of the Future: How We Can Use It To Heal Ourselves Now, Bear and Co. Publ, Santa Fe, USA., 1991.