高显色性白光LED调光系统研究与实现

发布时间：2018-07-28 14:00

【摘要】：发光二极管(LED:Light Emitting Diode)以发光效率高、寿命长、节能环保等优点,在建筑、信号照明、背光、显示、街道、室内照明等有着广泛应用。目前,实现白光LED光源在较宽范围内色温连续可调,又能在该范围内保持高的显色性,近年来成为研究的热点。针对宽色温范围内高显色性白光光源缺乏有效合成方法的问题,本文进行了以下研究工作。首先,根据光混合原理及脉冲宽度调制(PWM)方法,推导出两通道和三通道调光关系式。两通道调光法采用冷白和暖白LED合成白光,实现混合光源色温在3300K～7500K之内,偏差小于32K。然而,光源显色指数整体上较低,均小于90。三通道调光法采用了暖白/绿/蓝LED合成目标光源,测试结果表明:色温在3200K～7600K之间,其最大误差为1.82%,且显色指数在86.5～95.3之内,较两通道调光法有较大提升。其次,针对三通道调制的光源在低色温时显色指数不够高的现象,本文在三通道、两通道调光法基础上,根据由实验确立的相关色温与特定色坐标关系,提出一种"3+2"调光方法,通过分别控制红/绿/蓝/暖白(R/G/B/WW)驱动信号占空比实现白光光源调制。实验结果表明:当混合光源光通量设置为3001m时,色温在2900K～7600K范围内连续可调,色温偏差为0.56%,混合光源调节色温时光通量的起伏小于2.24%,显色指数Ra均在94～96之间,理论与实际偏差为不超过0.1;设置色温为5000K,当光通量取值在0～800 1m范围变化时,光通量偏差小于2%。最后,根据提出的"3+2"调光方法和设计指标,设计了一种远程智能调光控制系统。系统实现如下功能:通过智能手机APP或红外遥控器,实现光源开关、颜色变化、光通量调节、色温调节、恒光模式及自适应模式等,其中,恒光模式采用两块NRF24L01模块进行光照数据通信,经多次协调使环境光照强度与设定值趋于一致。本文提出的"3+2"调光方法,具有计算方法简单、调光精度高、易于硬件实现等特点。同时,构建的这套光控系统不仅能实现类太阳光的光照环境,也能对舞台、显示等不同光色效果的实现具有一定的指导作用。
[Abstract]:Light emitting diodes (LED:Light Emitting Diode) are widely used in buildings, signal lighting, backlight, display, street, indoor lighting and so on because of their advantages of high luminous efficiency, long life, energy saving and environmental protection. At present, the realization of white LED light source in a wide range of continuous color temperature adjustable, but also to maintain high color rendering in this range, in recent years has become a hot spot. In order to solve the problem of the lack of effective synthesis method for high color white light source in wide color temperature range, the following research work has been done in this paper. Firstly, according to the principle of optical mixing and the pulse width modulation (PWM) method, the two and three channel dimming equations are derived. Two channel dimming method uses cold white and warm white LED to synthesize white light. The color temperature of mixed light source is within 3300K~7500K, and the deviation is less than 32kg. However, the overall color rendering index of the light source is lower than 90. 5%. The three-channel dimming method uses warm white / green / blue LED to synthesize the target light source. The test results show that the maximum error of color temperature between 3200K~7600K is 1.82, and the color rendering index is within 86.5 ~ 95.3, which is much higher than that of two-channel dimming method. Secondly, aiming at the phenomenon that the color index of the three-channel modulated light source is not high enough at low color temperature, this paper based on the three-channel and two-channel dimming method, according to the relationship between the relative color temperature and the specific color coordinate established by the experiment, A "32" dimming method is proposed. The white light source is modulated by controlling the duty cycle of the red / green / blue / warm white (R/G/B/WW) driving signal respectively. The experimental results show that when the luminous flux of the mixed light source is set to 3001m, the color temperature can be continuously adjusted in the range of 2900K~7600K, the deviation of the color temperature is 0.56, the fluctuation of the luminous flux is less than 2.24 when the mixed light source adjusts the color temperature, and the chromogenic index Ra is between 94 and 96. The theoretical and practical deviations are not more than 0.1, and the color temperature is 5 000 K. When the luminous flux varies in the range of 0 ~ 800 1m, the deviation of luminous flux is less than 2. Finally, according to the proposed "32" dimming method and design index, a remote intelligent dimming control system is designed. The system realizes the following functions: through smart phone APP or infrared remote control, realize light source switch, color change, luminous flux adjustment, color temperature adjustment, constant light mode and adaptive mode, etc. In the constant light mode, two NRF24L01 modules are used to communicate the illumination data, and the environmental illumination intensity is consistent with the set value after several coordination. The "32" dimming method presented in this paper has the advantages of simple calculation method, high dimming precision and easy hardware realization. At the same time, the light control system can not only realize the sun-like illumination environment, but also can guide the realization of different light and color effects, such as stage, display and so on.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN312.8

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