【作者】 赵媛；

【导师】 张琢；

【作者基本信息】 哈尔滨工业大学 ， 仪器科学与技术， 2009， 硕士

【摘要】 LED具有环保、寿命长、低功耗等特性,近年来在机器视觉领域快速地应用和发展,LED驱动电路的研究和设计也成为关注的焦点。本课题设计主要应用于神光III原型装置靶场光电及控制系统中,监测仪和传感器的CCD用作在线观测靶场、摄取图像并进行图像处理,现场光线强弱对图像的分析和处理具有十分重要的作用,为此实验设计了绿光(波长在525nm左右)LED照明光源系统,通过调节照明系统光强可以灵活改变图像的亮度和对比度。本课题根据靶场内监测仪和传感器的光学系统照明需求,制定了光源的设计指标,如工作距范围、照明区域和LED的倾斜角度等参数,提出了碗型圆周阵列排布的光源设计方案,利用MatLab软件进行图像处理和理论计算,借助TracePro光学软件分析光源照度分布特点,设计电路并搭建光路,并对光源设计进行合理性验证。同时通过研究脉冲宽度调制(Pulse Width Modulation, PWM)技术的实现原理,由此设计基于脉冲宽度调制的LED电源驱动器,编写Verilog语言并运用Modelsim和ISE软件进行程序的仿真和综合,实现光源的手动调节方式;规定PC机与单片机的通信协议,PC机通过RS-232总线与单片机实现异步全双工的数据收发模式,利用现场可编程逻辑器件(Field Programmable Logic Array, FPGA)实现程控方式自动调节照明光源的光强。通过上述方法改善神光III原型装置靶场光电及控制系统中监测仪和传感器的CCD光照环境,提高图像品质,为图像处理后数据的可靠性和准确性提供良好的保障。更多还原

【Abstract】 In recent years, LED is developing and applying in Machine visual field quickly, because of its characteristics of environmental protection, long life and low power consumption, and the research and the design on LED driver circuit has also become the focus of attention. The subject is mainly used in the design and control of photovoltaic systems on Sheng Guang-III prototype device. CCD in the monitors and sensors, are used for online observation range, image incepting and image processing. The green LED light source (in 525nm wavelength) system has been experimented and been designed, because the strength of the light spot in image processing and analysis plays a very important role. The brightness and the contrast of images can been changed flexibly by adjusting the lighting system.This issue developed the design specifications on light source of monitor and sensor repeatedly, such as the parameters about the scope of the work regional, the lighting area on light source and the angle on LEDs, in accordance with the illumination requirements about the optics system of monitor and sensor, and put forward the light source array design about the bowl-type circular arrangement. The issue designed the circuit and structures the optical path by using image processing and theoretical calculations based on MatLab software and analyzing illumination distribution of the light source by TracePro optical software, and verified the reasonableness of the design about the light source. It was been researched that the realization of the principle of Pulse Width Modulation (PWM) technology, which designed the LED driver of light source based on PWM at the same while. The system achieved the way of the manual adjustment to the light source through preparation of Verilog programs and Modelsim and ISE software simulating and synthesising procedures ; The communications protocol was been provisioned with MCU , thereby , PC machines sent and received data with MCU through RS-232 bus using the full-duplex asynchronous mode. Finally using Field Programmable Logic Array (FPGA) achieved the function of adjusting the lighting strength of the light source automatically by the way of programmable controller. The scheme mentioned above can improve lighting conditions and enhance image quality to the CCDs in the monitors and sensors of the design and control of photovoltaic systems on Sheng Guang-III prototype device, and can provide the good protection to the reliability and the accuracy of data after image processing.更多还原