《基于cmos图像传感器的宽动态、低照度一体化摄像机的设计》由会员分享,可在线阅读,更多相关《基于cmos图像传感器的宽动态、低照度一体化摄像机的设计(100页珍藏版)》请在金锄头文库上搜索。
1、太原理工大学 硕士学位论文 基于CMOS图像传感器的宽动态、低照度一体化摄像机的设计 姓名:田书成 申请学位级别:硕士 专业: 指导教师:程永强 20100301 太原理工大学硕士研究生学位论文 I 基于 CMOS 图像传感器的宽动态、低照度一体化摄像机的设计 摘 要 目前,一体化摄像机以价格合理、性能完善、安装方便等优势,在监 控摄像机领域得到广泛应用。利用 CCD 图像传感器进行一体化摄像机的研 制,设计复杂,成本相对较高。CMOS 图像传感器产品技术越来越成熟, 其性能已经达到或超过 CCD。 利用 CMOS 图像传感器进行一体化摄像机的 研制,在保证高质量图像的前提下降低了设计复杂度和
2、产品成本。基于 CMOS 图像传感器的一体化摄像机在监控系统中有着巨大的应用价值。 本文采用“CMOS 图像传感器 + FPGA + 单片机”的设计方案,设计 了22倍PAL制一体化摄像机。 整个设计分为硬件电路设计和控制程序设计。 硬件电路设计采用模块化设计方法, 共分为四个模块: 图像采集模块、 FPGA 模块、单片机控制模块和电源模块。论文针对各模块的功能对主芯片进行 选型并完成了电路原理图的设计。PCB 的设计是在基于信号完整性分析的 基础上,通过对集总电路元件(电阻、电容和电感)和传输线等进行等效、 建模分析,从而把物理特性转化为电气模型。然后利用等效电气模型对整 个设计的电气性能进
3、行了优化,解决了 PCB 设计中的串扰、反射、电源分 配系统的轨道塌陷等问题,同时有效降低了整体设计的电磁干扰和辐射, 最终设计出性能稳定的硬件电路。控制程序分为 CMOS 图像传感器初始化 程序、自动聚焦程序、片内 OSD 程序、RS-485 通信程序。CMOS 图像传 感器内部包含 400 多个控制寄存器和变量, 这些寄存器和变量可以通过 I2C 接口进行读写。只有对这些寄存器和变量进行正确的配置,图像传感器才 太原理工大学硕士研究生学位论文 II 能按设计要求工作。一方面利用单片机的 I2C 通信机制,通过对多个彼此 存在相关性的寄存器和变量进行配置,实现了传感器芯片的初始化。同时, 通
4、过对传感器芯片内部相关命令寄存器的配置和单片机的时序控制,实现 片内 OSD 功能。另一方面利用单片机的 SPI 通信机制,实现了与 FPGA 之 间的通信,单片机读取 FPGA 的聚焦评价函数值,结合改进的爬山搜索策 略实现了自动聚焦。此外,单片机通过 RS-485 通信机制实现远程监控。 本文设计的一体化摄像机动态范围达到 52dB,最低照度为 0.09Lux, 具有较高的性价比。满足一体化摄像机的主要参数及性能指标,可广泛应 用于港口、视频会议、智能交通、智能小区等监控系统中,应用前景较好。 关键词:CMOS 图像传感器,FPGA,单片机,一体化摄像机,OSD 太原理工大学硕士研究生学位
5、论文 III DESIGN OF WIDE DYNAMIC, LOW ILLUMINATION INTEGRATED CAMERAS BASED ON CMOS IMAGE SENSOR ABSTRACT At present, the integrated camera with reasonable price, good performance, installation easy and other advantages, they are widely used in the field of surveillance cameras. Using CCD image sensors
6、 to design integrated camera, the design is complex and cost is relatively high. The CMOS image sensor product technology is more and more matures, its performance has met or exceeded the CCD. Using CMOS image sensor develop for integrated camera can reduce the design complexity and cost of the prod
7、uct in the premise of ensuring high image performance. The integrated camera based on CMOS image sensor in surveillance system has great application value. In this paper, the scheme of “CMOS image sensor + FPGA + MCU“ is adopted to design the 22 times PAL integrated camera. The whole design is divid
8、ed into hardware circuit design and control programming design. The hardware circuit uses modular design method and the whole design is divided into four modules: image acquisition module, FPGA module, MCU control module and power module. This paper selects main chip according to the function of eac
9、h module and complete the schematic design. PCB design is 太原理工大学硕士研究生学位论文 IV based on the signal integrity analysis, through the lumped circuit elements (resistors, capacitors and inductors) and transmission lines are equivalent, modeling and analysis, and thus the physical properties change into el
10、ectrical model. Then, the equivalent electrical model is used to optimize the electrical properties of the entire design; so the problem of crosstalk, reflections and power distribution system orbital collapse in PCB design are solved. At the same time, effectively reducing the overall design of ele
11、ctromagnetic interference and radiation, and the final hardware circuit has stable performance. Control program is divided into CMOS image sensor initialization program, auto-focus program, OSD program and RS-485 Communication program. CMOS image sensor contains more than 400 internal control regist
12、ers and variables, which registers and variables can be read and write through the I2C interface. Only those registers and variables are configured correctly, the image sensor can work according to design requirements. On the one hand, using I2C communication mechanisms of MCU, through the number of
13、 registers and variables correlated with each other configured to implement initialization of the sensor chip. Meanwhile, through the internal related command registers of the sensor chip to configuration and timing control of MCU to achieve OSD function. On the other hand, also in the MCU, SPI comm
14、unication mechanism used to achieve communication between with the FPGA. The MCU reads the value of the focusing evaluation function of FPGA, combined with improved climbing search strategy to achieve the auto-focus; In addition, the microcontroller 太原理工大学硕士研究生学位论文 V through the RS-485 communication
15、 mechanism to achieve remote monitoring and control. The dynamic range of the integrated camera designed in this paper up to 52dB, its minimum illumination is 0.09Lux, and it is cost-effective. Its parameters and performance meet the main parameters and performance indicators of the integrated camer
16、as; it can be widely used in ports, video conferencing, intelligent transportation, intelligence community and other monitoring systems and its application prospect is better. KEY WORDS: CMOS image sensor, FPGA, MCU, integrated camera, OSD 太原理工大学硕士研究生学位论文 1 第一章 绪 论 1.1 论文研究背景及意义 随着社会不断进步, 经济快速发展和技术突飞猛进, 公共秩序安全、生产安全、财 产安全等越来越受到人们的重视, 从而使以视频信息为特征的视频监控更为广泛地被应 用在各行业领域。如从早期金融银行、道路交通、大型连锁超市的安全监控向个人、家 庭应用发展,从传统的安防监控向管理和生产经营监控发展,从室内到无人值守特定场 合应用的监控。可以相信,市场的强劲需求会进一步激励和催化技术的不断发展,特别 是最近比较热门的平安城市监控系统需求。 作为