A Novel Color Control Method for MultiColor LED Systems to Achieve High Color Rendering Indexes

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Original languageEnglish
Pages (from-to)8246-8258
Journal / PublicationIEEE Transactions on Power Electronics
Issue number10
Online published19 Dec 2017
Publication statusPublished - Oct 2018


A novel color control method for multicolor LED systems is proposed. The proposed control method can achieve high color rendering indexes by approximating the spectral power distributions (SPDs) of black bodies. The SPD control of the LED system is accomplished by combining a sensory module and a control module. The sensory module implements a linear function that merges readouts from multiple color sensors and maps the data into the optical powers of the LED channels, while the control module utilizes such data in a feedback loop to control the optical power of each channel. Compared with conventional control methods, the proposed method has the merits of 1) not requiring an accurate electrical-optical system model, 2) requiring only a few spectra data for offline calibration, 3) requiring only RGB color sensors for online operations of tetra-color and penta-color LED systems, 4) providing consistent color with high color rendering index, and 5) being applicable to all multicolor LED systems. The proposed control method is evaluated by applying it to an example of an RGB-amber LED system driven by a buck-type single-inductor-multiple-output LED driver with the LED channels connected in series. Experimental results have verified the effectiveness and robustness with ambient temperature of the proposed control method.

Research Area(s)

  • Color, Image color analysis, Light emitting diodes, Lighting, Lighting control, Optical sensors, red-green-blue-amber (RGBA) LED system, Sensor phenomena and characterization, Sensor systems, single-inductor-multiple-output (SIMO) LED driver, multicolor light-emitting-diode (LED) system