论文总字数：30307字

摘 要

在日趋复杂的安全形势下，海关、港口、车站等重要公共场所的安全检查已经成为保障人们的人身及财产安全的第一道屏障。在这种背景下，基于X射线探测的行李X射线安检机凭借其成本低、可实现非接触式的快速检测等优点成为了车站、机场等重要公共场所的主流行李安检设备。本课题中针对x射线安检设备中的探测电路进行研究，采用集成I-V转换芯片EMT1010设计了64通道的双能线阵X射线探测板，并搭建了数据采集传输平台将探测板输出的I-V转换结果转换成数字信号并发送给PC端上位机进行处理，此外还对探测板和数据采集传输平台的主要电路参数进行了测量。

基于集成I-V转换芯片EMT1010的线阵X射线探测板由两组完全相同的I-V转换电路组成，每组I-V转换电路由两片EMT1010芯片采用菊花链方式级联构成，每组转换电路可以完成64个探测通道的I-V转换，两组转换电路可同步工作，同时对高能和低能两组探测器进行I-V转换。

数据采集传输平台由数据采集板、可编程逻辑控制传输板以及PC端上位机软件组成。数据采集板对探测板输出的差分电压信号进行放大，并对其进行AD转换。可编程逻辑控制传输板对探测板和数据采集板进行时序控制，并将数据采集板的转换结果通过板载的USB通信电路按一定的数据帧格式传送给PC端上位机。PC端上位机对接收到的数据进行处理并通过图形界面显示。

探测板和数据采集传输平台的电路参数测量主要包括数据采集板的有效位数的测量；探测板未接入探测器时和数据采集板级联时的有效位数的测量；探测板接入探测器时和数据采集板级联时的有效位数的测量等。

关键词：X射线、安检、线阵X射线探测器、数据采集传输、有效位数

Abstract

In the increasingly complex security situation, the security check of customs, ports, railway stations and other public places have become the first barrier to protect people's personal and property safety. In this background, the X-ray baggage detection machine which can do the detection quickly, with non-contact, has been the mainstream of baggage screening equipment in railway stations, airports and other important public places. This paper studies the detecting circuitry of x-ray screening equipment, and designed a 64-channel dual-energy X-ray detecting circuitry for linear array X-ray detector, which based on the integrated I-V conversion chip EMT1010. In addition, a platform for data acquisition and transmission is set upped to deal with the output of the detecting circuitry. Besides, some of the most important parameters of the detecting circuitry and the platform for data acquisition and transmission is measured to assess the performance of the circuits we designed.

The detecting circuitry is composed by two identical I-V conversion circuit. Each of them consists of two daisy chain cascaded EMT1010 chips. The two identical I-V conversion circuit works at the same time and each can convert 64 channels output of the X-ray detector.

The platform for data acquisition and transmission is composed by a data collect board, a CPLD and USB transfer board and an upper-computer software. The data collect board handles the output of detecting circuitry. The CPLD and USB transfer board controls the detecting circuitry and data collect board and sends the data, collected by data collect board, to the upper-computer software, while the upper-computer software processes the data received and show the image in the screen.

The most important parameter of the detection circuitry and the platform is the effective bits. In this subject we measured the effective bits of the data collect board. Besides, the effective bits of the detection circuitry is also measured.

Key words: X-ray, safety inspection, linear X-ray detectors, data collection and transmission, ENOB

目 录

摘 要 I

Abstract II

第一章 绪 论 1

1.1 课题背景与意义 1

1.2 X射线安检设备工作原理及国内外发展现状 1

1.3本课题的研究内容 2

第二章 线阵X射线探测板设计 4

2.1线阵X射线探测系统框架 4

2.2线阵X射线探测板设计要求 5

2.3线阵X射线探测板的设计框架 5

2.4基于集成I-V转换芯片EMT1010的探测电路设计 7

2.4.1 EMT1010集成芯片的主要电路特性 7

2.4.2 EMT1010积分电路原理及积分时间的控制 9

2.4.3 EMT1010多片级联方式及芯片外围电路设计 10

2.5探测板PCB布板 11

第三章 数据采集传输平台设计及时序控制逻辑的实现 13

3.1数据采集传输平台框架 13

3.2数据采集板设计 15

3.2.1模拟信号放大电路 15

3.2.2 AD转换电路 16

3.2.3电源电路 17

3.2.4数据采集板布板 17

3.3时序控制逻辑的实现 18

3.3.1时序控制逻辑框架 18

3.3.2 EMT1010控制逻辑设计与验证 19

3.3.3 ADS8363控制逻辑设计与验证 21

3.3.4USB数据传输的控制逻辑设计与验证 24

第四章 电路性能测试 27

4.1数据采集板有效位数的测量 27

4.2探测板未接入探测器时与数据采集板级联时的有效位数测量 28

4.3探测板接入探测器时与数据采集板级联时的有效位数测量 30

4.4数据分析 31

第五章 总结与展望 32

5.1 全文总结 32

5.2 未来工作展望 32

参考文献 33

致谢 34

剩余内容已隐藏，请支付后下载全文，论文总字数：30307字