| With the progress of the LED technology,LED has been widely applied in different areas.Different wavelengths of light and different color temperatures play an important role in the day and night biological rhythm of people.Therefore,the LED light resouce with adjustable spectrums and color temperatures has a great application prospect in domains such as medical treating,home,public facilitation,company,etc.To satisfy the requiements that the spectrum and color temperature of LED light source should be disjustable,a dimming system based on LED light source is designed in this paper.By means of the client wireless control,the system realizes the spectrum and color temperature adjustment of LED light source.This paper firstly reviews the current development status of the LED chip and its drive technology,analyzes the theory that RGB tricolor LED spectrum is adjustable based on the principle of mixing light,and establishes the conversion relationship between the tricolor LED and light spectrums,so that the objective color temperature values and the duty ratio values of RGB tricolor LED can be conversed mutually.Then according to the requirements that the light source should be adjustable and the light intensity should be stable,combining with analyzing the RGB tricolor LED light source stability factors,the paper designs the hardware lighting dimming system and the software control algorithm.The hardware dimming system includes the MCU circuit module,the Wi-fi communication module,the LED driving circuit module,and the detecting module which is used to keep the light intensity stable.The software includes two items: the holistic control algorithm and several patial control algorithms.To accomplish the control process,the mathematical model of the LED dimming system is established.Besides,the suitable fuzzy PID algorithm is adopted according to the transfer function.As a result,the lighting dimming system with the strong anti-interference ability and the stable light intensity is realized.Finally,through the software simulation and the hardware test,the paper accomplishes the LED dimming system with tunable spectrums.This research has certain theoretical meanings and practical values for both the the control algorithms for the light intensity and the control of RGB tricolor LED. |
