基于单片机的超声波探伤仪

摘要

超声波探伤仪是目前工业制造和现代化检测的重要途径之一，广泛的应用在质量检测和产品检测中，通过使用其产品能够有效地降低产品次品的风险。尽管随着电子技术的发展， 国内出现了一些数字化的超声检测仪器，但其数据处理及扩展能力有限，缺乏足够的灵活性。本设计超声检测技术，基于AT89C52单片机开发的超声探伤仪智能系统的硬件组成、软件设计和抗干扰措施, 以脉冲反射式超声探伤仪为代表研制完成一个良好的数字化的超声检测平台，该系统具有测量、数字显示、A/D转换等功能, 并具有工作稳定、性能好等优点。为以后进一步的更深入的超声数字信号处理研究打下了良好的基础。

超声检测是无损检测的主要技术之一，已被广泛地应用于在线质量控制、在役设备和关键零部件的安全检测之中。超声波探伤仪作为超声波检测技术实现的载体，在超声波检测中具有重要的研究意义。为提高超声检测的可靠性和效率，开发研制数字化、智能化、自动化、图像化的超声波无损探伤系统是当今无损检测技术的必然趋势。

本文主要介绍超声波透射式探伤仪的设计，首先介绍超声波检测的基本原理以及其发展历史、目前现状等。然后对设计中的数字式超声波探伤仪的总体设计及各功能模块进行了探讨，确定了探伤仪设计的解决方案并对系统解决方案中的主控芯片和可编程逻辑控制芯片进行了选型。之后重点研究数字化超声波探伤仪系统的硬件设计，包括超声波的发射电路，接收电路，信号调理电路以及数据采集处理系统的设计和实现。最后介绍了数字超声无损探伤仪系统的软件设计，对系统软件设计的总体流程、超声波激励脉冲信号产生、数据采集系统的逻辑控制以及回波信号的数据处理进行了介绍。

关键词：无损检测；超声波探伤；AT89C52；信号调理，高速数据采集

Abstract

Ultrasonic nondestructive testing is one of the most widely used nondestructive testing methods in modern industrial production. It is of great significance to improve the quality and reliability of products.With the development of electronic technology, some digital ultrasonic testing instruments have appeared in China, but their data processing and expansion capabilities are limited and they lack sufficient flexibility.Ultrasonic testing technology, the design of ultrasonic flaw detector intelligent system based on AT89C52 single chip microcomputer development hardware composition, software design and anti-interference measures, represented by the pulse reflection type ultrasonic flaw detector was developed to complete A good platform for the digital ultrasonic testing, the system has measurement, digital display, A/D conversion, and other functions, and has the advantages of working stability, good performance.It lays a good foundation for further research on ultrasonic digital signal processing.

Ultrasonic testing is one of the main techniques of nondestructive testing. It has been widely used in online quality control, in-service equipment and safety testing of key parts.As the carrier of ultrasonic testing technology, ultrasonic flaw detector has important research significance in ultrasonic testing.In order to improve the reliability and efficiency of ultrasonic testing, it is an inevitable trend to develop a digital, intelligent, automatic and pictorial ultrasonic nondestructive testing system.

This paper mainly introduces the design of ultrasonic transmissive flaw detector, first introduces the basic principle of ultrasonic testing and its development history and present situation.Then, the overall design and functional modules of the digital ultrasonic flaw detector are discussed, the design solution of the flaw detector is determined, and the main control chip and the programmable logic control chip in the system solution are selected.Then the hardware design of the digital ultrasonic flaw detector system was studied, including the design and implementation of the transmitting circuit, the receiving circuit, the signal conditioning circuit and the data acquisition and processing system.Finally, the software design of digital ultrasonic nondestructive flaw detector system is introduced, and the overall process of system software design, the generation of ultrasonic excitation pulse signal, the logic control of data acquisition system and the data processing of echo signal are introduced.

Keywords: Nondestructive testing;Ultrasonic testing;AT89C52.Signal conditioning, high-speed data acquisition

目录

摘要............................................................................................................................. I

Abstract................................................................................................................... III

第一章 绪论............................................................................................................. 1

1.1研究目的与意义........................................................................................ 1

1.2超声波检测技术的发展............................................................................ 3

1.3超声波探伤仪的发展................................................................................ 6

1.4课题研究内容及章节安排........................................................................ 8

第二章 超声波检测基本原理及方法................................................................... 8

2.1超声波的基本性质.................................................................................... 8

2.1.1超声波的速度及波长.................................................................... 9

2.1.2超声波的衰减................................................................................. 9

2.2超声换能器................................................................................................. 9

2.2.1超声换能器的定义......................................................................... 9

2.2.2超声换能器的主要性能参数...................................................... 10

2.3超声波探伤的原理.................................................................................. 10

2.3.1超声波探伤方法的分类.............................................................. 10

2.3.2透射式检测方法........................................................................... 10

2.4机械振动与超声波.................................................................................. 12

2.4.1超声场的基本物理量和超声波波型......................................... 12

2.4.2金属探伤中的超声波波型.......................................................... 13

2.5超声场及介质的声参量.......................................................................... 14

2.5.1描述超声场的物理量.................................................................. 14

2.5.2介质的声参量............................................................................... 15

第三章 系统硬件整体结构框图及设计............................................................. 15

3.1系统硬件整体结构框图.......................................................................... 15

3.2主控制器设计.......................................................................................... 16

3.2.1芯片介绍....................................................................................... 16

3.2.2时钟电路设计............................................................................... 19

3.2.3复位电路设计............................................................................... 19

3.3超声波控制电路...................................................................................... 20

3.3.1超声波传感器............................................................................... 20

3.3.2超声波电路设计........................................................................... 21

3.4报警电路................................................................................................... 21

3.5显示电路设计......................................................................................... 22

第四章 系统软件部分设计.................................................................................. 24

4.1主程序流程图.......................................................................................... 24

4.2 程序设计.................................................................................................. 25

第五章 系统仿真调试部分.................................................................................. 32

5.1  软件研发的背景................................................................................... 32

5.2  软件程序设计....................................................................................... 33

5.3  基于Proteus电路图绘制.................................................................... 34

第六章 结束语....................................................................................................... 35

参考文献................................................................................................................. 37

致谢.......................................................................................................................... 39