毫米波无源成像系统伺服扫描机构设计及其控制单元实现

发布时间：2019-06-11 12:22

【摘要】：毫米波具有很强的穿透能力,能够穿透云雾、衣物、纸板等物体。自然界任何物体都会辐射毫米波波段的能量,且不同材质、温度的物体所辐射的毫米波能量不同,其中金属物体和非金属物体所辐射的毫米波能量差异明显。毫米波无源成像系统利用人体和金属物体辐射的毫米波能量的差异,实现被动成像。该成像技术具有无辐射、非接触式的特点,对人体的健康和隐私具有很好的保护作用,能够很好的满足机场、车站、党政机关等公共场所对人体安检的应用需求。本文依托相关的科研项目,综合考虑到成像机制的性能差异性和可实现性、成像系统各硬件部件的相互关联性、成像系统各参数指标的相互制约性、以及总体系统的设备成本等因素,重点研究了毫米波无源成像系统的伺服扫描机构,及其控制单元的设计与实现。具体完成的工作如下:1.研究了毫米波无源成像系统的总体方案,分析了成像系统的两种不同架设方案对相关参数的影响,并分析了两种架设方案的优缺点。2.研究了伺服扫描机构相关参数之间的关联性和制约性;根据伺服扫描转台机械结构的差异,分析并设计了“梯形”和“正弦”两种扫描特性曲线;针对这两种扫描特性曲线,分别讨论了扫描帧速率、成像视场高度、扫描峰值角速度和最大角加速度之间的制约关系,并据此来选取满足系统指标要求的合适的参数组合。3.研究了伺服扫描机构的伺服电机、测角编码器、机械传动方式等;根据总体系统对伺服扫描机构的功能和指标要求,完成了伺服扫描机构总体实现方案的设计,进行了转台的设计与实现。4.设计并实现了伺服控制单元。根据系统对伺服控制单元的要求,完成了基于数字信号处理器DSP TMS320F28335的伺服控制板的设计与实现,并完成了与系统其他硬件单元的通信调试;完成了伺服控制相关的软件设计与编写。5.针对实验室前期的成像系统,以及项目组最新研制的透镜天线、阵列通道等,设计并实现了“梯形”加减速二维扫描模型,完成了室内外单通道成像实验。
[Abstract]:Millimeter wave has a strong penetration ability, can penetrate clouds, clothing, cardboard and other objects. Any object in nature can radiate the energy of millimeter wave band, and the millimeter wave energy of different material and temperature object is different, among which the millimeter wave energy of metal object and non-metallic object is obviously different. Millimeter wave passive imaging system makes use of the difference of millimeter wave energy between human body and metal object to realize passive imaging. The imaging technology has the characteristics of no radiation and non-contact, has a good protective effect on human health and privacy, and can meet the application needs of human security inspection in airports, stations, party and government organs and other public places. Based on the relevant scientific research projects, this paper takes into account the performance difference and realizability of imaging mechanism, the correlation of the hardware components of the imaging system, and the mutual restriction of the parameters and indexes of the imaging system. As well as the equipment cost of the overall system, the servo scanning mechanism of millimeter wave passive imaging system and the design and implementation of its control unit are studied in detail. The specific work accomplished is as follows: 1. The overall scheme of millimeter wave passive imaging system is studied, the influence of two different erection schemes of imaging system on the related parameters is analyzed, and the advantages and disadvantages of the two erection schemes are analyzed. 2. The correlation and restraint between the relevant parameters of the servo scanning mechanism are studied, and according to the difference of the mechanical structure of the servo scanning turntable, the scanning characteristic curves of "ladder" and "sine" are analyzed and designed. According to these two scanning characteristic curves, the constraints among scanning frame rate, imaging field of view height, scanning peak angular velocity and maximum angular acceleration are discussed respectively, and the appropriate parameter combination to meet the requirements of the system index is selected. 3. The servo motor, angle measuring encoder and mechanical transmission mode of servo scanning mechanism are studied. According to the function and index requirements of the servo scanning mechanism, the overall realization scheme of the servo scanning mechanism is designed, and the turntable is designed and realized. 4. The servo control unit is designed and implemented. According to the requirements of the system for the servo control unit, the design and implementation of the servo control board based on the digital signal processor DSP TMS320F28335 are completed, and the communication and debugging with other hardware units of the system are completed. The software design and programming of servo control are completed. 5. Aiming at the imaging system in the early stage of the laboratory, as well as the lens antenna and array channel newly developed by the project team, the "ladder" acceleration and deceleration two-dimensional scanning model is designed and implemented, and the indoor and outdoor single channel imaging experiment is completed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN015

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