大功率LED照明控制器的研究-机械电子工程专业毕业论文.docx

Classified Index: :
Dissertation for the Master Degree of Engineering
RESEARCH OF HIGH-POWER LED LIGHTING CONTROLLER
Candidate:
Wang Wenchang
Supervisor:
Associate Prof . Yang Xiaoping
Academic Degree Applied for:
Master of Engineering
Speciality:
Mechatronics Engineering
Affiliation:
Shenzhen Graduate School
Date of Defence:
Dec, 2009
Degree Conferring Institution:
Harbin Institute of Technology
摘要
由于具备长寿命,低能耗,环保等优点,LED 被越来越广泛的应用到照明应用中。家用或商用通用照明应用中,在保证照明效果的情况下, 如果能发挥 LED 颜色多样性的特点,LED 的应用将会更深入人心。
在 LED 照明应用中,还有许多需要解决的问题,如驱动,数字调光,结温升高引起的色衰控制,混色控制,散热等问题。
本文对 LED 的光特性进行了分析,找出了影响光质量的主要因素。考虑到目前的 RGB LED 混色系统色温和显色性的不足,本设计加入了琥珀色,使得色彩更饱满,色温范围更大。针对结温升高会造成 LED 发光光谱和光通量变化的问题,本文提出了一个光学反馈闭环 PI 控制解决方案,采用 PSoC(片上可编程控制系统)控制芯片,实现了精准的色彩控制。
在研究 LED 电特性的基础上,找出了合理的驱动方式,并对 LED 的恒流驱动电路进行了设计和分析。并在此基础上加入了 LED 故障诊断电路,用于诊断 LED 的短路和开路。本设计采用 PrISM 调制方式进行数字调光,通过伪随机计数器生成的高频非周期性的信号输出,获得一个从 EMI/EMC 角度而言噪声较低、便于使用的调制信号。
本设计的人机界面采用基于开关电容技术的触摸板。在对电容感应原理进行了深入的研究的基础上,通过硬件和软件的设计,很好地解决了触摸按键的抗干扰问题。并在软件设计中引入数学上求质心的算法提高了触摸感应的精度。
随后进行了系统级硬件的设计,包括芯片级设计和外围电路设计。在软件设计中考虑了 Bin 码的差异,进行了 Bin 码的补偿。本文的最后,讨论了大功率 LED 照明控制器后续的研究路线,对散热管理和通信接口提出了自己的看法。
关键词:RGBA;LED;混色控制;PI;PSoC;电容感应
Abstract
Because of advantages such as long lifetime, low power consumption, and no mercury containing, LEDs are widely used in a variety of general-purpose illumination applications. In the family mercial general-purpose lighting applications, not only need to ensure lighting effects, but also should play to the advantage of LED colors, LED applications will be more popular.
In the LED color mixing applications, there are many issues to be solved, such as drive, digital dimming, color mixing, color decay caused by the rise of junction temperature, thermal management, and so on.
In this paper, the optical characteristics of LED are analyzed to identify the main factors affecting the quality of light. Taking into account the lack of color temperature and color rendering of current RGB LED color mixi