Repetitive Learning Control Design for LED Light Tracking

A lighting system composed of three color light-emitting diode (LED) strings is considered. On the basis of a simplified dynamic model (with uncertainties) for the aforementioned system, the tracking of (possibly complex) periodic reference signals (with known period) for both the light color and intensity is achieved by designing, for each LED string, a decentralized repetitive learning control. Experimental results illustrate the effectiveness of the proposed approach in a practical user-friendly scenario: the color coordinates are obtained by an external low-cost red, green, blue sensor which allows for measuring the overall lighting effects (including external disturbances) while increasing the overall energy saving. A detailed theoretical analysis of the learning control design for first-order linear systems with zero relative degree under suitable assumptions is also included.