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摘 要

针对盲人行走过程中无法了解到前方是否存在障碍物的问题，本文设计了一种新型的基于单片机控制的盲人自动避障装置，且该装置带有语音提醒功能。本方案通过超声波的发送和接收来检测前方一段距离内是否有障碍物存在，若有，则语音提醒模块发出提醒信息。语音电路根据障碍物距离发出不同频率的报警声音，以提醒使用者。此时使用者可按下按键，报警响声中断。报警声响起时，电路板上的LED灯会亮起，以提醒路人让路。

本文所采用的主要芯片有超声波测距模块US-100,语音芯片ISD4004,音频功放TDA2822。

本装置的设计所采用的主要方法是：采用两个超声波模块进行测距，其中一个模块的超声波探头垂直向下，另一个模块的超声波探头斜向下。二者夹角为60°。由于超声波模块US-100的测距范围是：2㎝-450㎝。因而采用这样的方式进行测距，水平测距范围是0.6㎝-389㎝。采用这样的方法进行测距与只采用一个超声波模块平行进行测距相比较的优点是：（1）当前方的有坑时，也能检测出来并及时报警（2）能检测到高于地面的所有障碍物。语音芯片ISD4004可存储8分钟的录音时间，本芯片录了四段录音：当离障碍物389㎝-200㎝时播放第一段录音，当离障碍物200㎝-100㎝时播放第二段录音，当离障碍物100㎝-0㎝时播放第三段录音，当前方有坑或沟时播放第四段录音。

通过多次实物验证，能实现预期目标。

本文是在基于单片机控制的超声波测距原理的基础上，配以其他的外围电路来实现避障功能的。此装置简单实用且便携，设计在很大程度上解决了盲人行走中的安全问题。

关键字：单片机AT89S52；超声波测距US-100；语音提醒ISD4004；音频功放TDA2822

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Abstract

In view of the problem that the blind can’t understand whether there are obstacles in front during walking, a new obstacle-avoidance automatic device was designed, which is based on single-chip. In addition, it has the function of voice-reminding. The scheme is by means of ultrasonic’s sending and receiving to detect a distance ahead whether there exist within the obstacles. If any, voice reminder module is a reminder. Voice reminder module sends the frequency of alarm sound according to the different obstacle distance, to remind the user. At this time the user can press the set key, alarm sound interruption. When alarm sound up, the circuit boards will light up LED to warn the stranger for its way.

This paper provides the chips have ultrasonic ranging module US-100, ISD4004 voice chip, TDA2822 audio power amplifier.

The design of this device with main method is: the two ultrasonic module sequence, one of the modules of ultrasonic probe vertically down, the other a module of ultrasonic probe inclined down. Both an Angle of 60 °. Because of the ultrasonic module US-100 range is: 2 ㎝-450 ㎝. So it is this way sequence, level range is 0.6 ㎝ range-389 ㎝. Using such methods and only use a range of ultrasonic module parallel sequence advantage is: the current party there pits, also can test out and even the police. ISD4004 voice chip can be stored 8 minutes recording time, the chip to record four recording: when the obstacles 389 ㎝-200 ㎝ played the first recording, when the obstacles 200 ㎝-100 ㎝ played the second recording, when the obstacles 100 ㎝-0 ㎝ played the third recording, the current party a pit or groove fourth recording played.

This paper is based on single chip microcomputer control on the basis of the principle of ultrasonic ranging, match with other peripheral circuit to achieve obstacle avoidance of the function. This device is simple and applicable portable, in the very great degree the blind man walk to solve the security issue.

Keywords: Monolithic integrated circuit AT89S52; Ultrasonic ranging US-100; Voice remind ISD4004; TDA2822 audio power amplifier

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目 录

摘 要 .................................................................... I Abstract ................................................................. II 1 前言 ................................................................... 1

1.1设计的目的和意义 ................................................... 1 1.2 盲人避障技术的研究现状 ............................................ 2 2 设计所用的主要技术 ..................................................... 3

2.1 硬件技术 .......................................................... 3 2.2 软件技术 .......................................................... 3 3 系统设计 ............................................................... 5

3.1 总体框架 .......................................................... 5 3.2 各个模块的工作流程 ................................................ 5 3.3 系统的软件流程图 .................................................. 5 3.4 系统各个模块的设计 ................................................ 6

3.4.1 超声波测距模块 ............................................... 6 3.4.2 语音模块设计 ................................................ 11 3.4.3 音频功放模块 ................................................ 16 3.4.4 单片机最小系统及其简单应用 .................................. 19

4 测试部分 .............................................................. 24

4.1 实验方法 ......................................................... 24

4.1.1 超声波测距的方法 ............................................ 24 4.1.2语音芯片的使用方法 .......................................... 26 4.1.3 TDA2822的使用方法 .......................................... 27 4.2 实验对象 ......................................................... 28

4.2.1超声波测距模块 .............................................. 28 4.2.2 语音电路的使用情况 .......................................... 28 4.3 软件设计思想 ..................................................... 28 5 实验结果分析与展望 .................................................... 30

5.1实验结果分析 ...................................................... 30 5.2实验结果展望 ...................................................... 30 参考文献 ................................................................. 32

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