超聲波測距儀畢業(yè)論文


頁數(shù)：48 字數(shù)：16799

摘要
本文詳細介紹了一種基于單片機的單脈沖反射式超聲測距系統(tǒng)。該系統(tǒng)以空氣中超聲波的傳播速度為確定條件，利用反射超聲波測量待測距離。并且描述了系統(tǒng)研制的理論基礎，超聲傳感器等部分的電路設計以及使用了性能優(yōu)良的 PHILIPS單片機 P89LPC932后對系統(tǒng)所起的積極作用。課題初步計劃是在室內(nèi)范圍的測距。系統(tǒng)的設計及器件的選擇也正是在這個基礎上進行的。
超聲測距系統(tǒng)的設計原理以達到更優(yōu)的系統(tǒng)性能為目的。為適合不同的測距范圍，單片機設置了遠近兩種發(fā)射模式，即遠距時使用高放大倍數(shù)放大，近距使用低放大倍數(shù)放大。根據(jù)回波信號特點得到了最佳接收機的組成。利用雙門限檢測的原理，檢測單元實現(xiàn)了滑動門限檢測和脈寬檢測，一定程度上以降低系統(tǒng)檢測誤識率。并且采用PHILIPS P90LPC932微控制器，完成數(shù)據(jù)的采集，處理，顯示。
論文概述了超聲檢測的發(fā)展及基本原理，介紹超聲傳感器的原理及特性。對于測距系統(tǒng)的一些主要參數(shù)進行了討論。并且在介紹超聲測距系統(tǒng)功能的基礎上，提出了系統(tǒng)的總體構(gòu)成。針對測距系統(tǒng)發(fā)射、接收、顯示部分的總體設計方案進行了論證。進一步介紹了單片機 P89LPC932應用在系統(tǒng)中的應用，分析了系統(tǒng)各部分的硬件及軟件實現(xiàn)。
本設計以P89LPC932單片機為主控制器。采用6位數(shù)碼管顯示器，數(shù)碼管接口基于MAX7219進行設計。



關(guān)鍵詞：超聲波；測距；P89LPC932；MAX7219


ABSTRACT
The thesis introduces a kind of single-pulse-reflection ultrasonic distancemeter system in detail based on microcontronller. The system could measure certain distance with the reflected wave on condition in which the speed of transmitting wave is fixed. It generally specifies the theoretical foundation of the system, the electronic design of the ultrasonic sensor. Because the project is the initial part of ultrasonic signal detection based on DSP, it is limited in indoor range in advance. So the design of the system and the choice of the components are decided according to the reason.
The scheme of each part is designed to acquire better performance of the system. In order to meet the different distance range, it arranges two transmitting modes in microcontroller: hign gain applies to far mode, while low gain applies to near mode. What is more, it makes use of the integrated chips to simplify the whole configuration, such as ingtegrated filter and programmable gain amplifier, in the optimum receiver that is based on the characters of the receiving waves. And to reduce the rate of misdetection, it carries out the double-threshold detection including amplitude detection and pulse-width detection. Moreover, the PHILIPS P89LPC932 microcontroller is employed in this system to achieve the function of collecting, processing, and displaying of data.
This paper summarizes the development and foudamental principle of ultrasonic detection. Then it presents the theory and characters of ultrasonic sensor. At the same time, it discusses a number of main technical parameters. Moreover, it proposes the whole structure of the system by introducing the function of ultrasonic distancemeter. And then the transmission, receiver, display scheme of this distancemeter system is brough out. Specially, after the application of P89LPC932 microcontroller, it analyzes the hardware and software realization of each part in this system.
This design with the P89LPC932 single slice machine id main controller, adopt 6figures tube displays, the figures tube connects to carry on establish according to the MAX7219.

Keywords: Ultrasonic wave；Distance measurement；P89LPC932；MAX7219
目錄

摘要 1
ABSTRACT 2
第1章 引言 1
第2章 超聲波測距儀原理及設計要求 2
2.1 超聲波測距儀簡介 2
2.2設計要求 4
2.3設計方案的確定 5
第3章 超聲波測距儀的硬件設計 5
3.1超聲波發(fā)送器的設計 5
3.2 超聲波接收器的設計 6
3.3 基于DS18B20的溫度測量電路 8
3.4 LED顯示電路設計 9
3.5 基于P89LPC932的主機電路設計 13
第4章 超聲波測距儀的軟件設計 19
4.1超聲波測距儀的軟件規(guī)劃 19
4.2 DS18B20的接口程序設計 20
4.2.1 DS18B20的初始化 20
4.2.2 字節(jié)寫DS18B20程序 20
4.2.3 字讀DS18B20程序 20
4.3 顯示程序設計 21
4.3.1 MAX7219的初始化 21
4.3.2 字寫MAX7219程序 22
4.3.3 顯示子程序 22
4.4 距離計算及其程序?qū)崿F(xiàn) 22
4.4.1 溫度補償 23
4.4.2距離計算 24
4.4.3 數(shù)制轉(zhuǎn)換與數(shù)據(jù)標定處理 24
4.5 主程序與P89LPC932的初始化程序 25
4.5.1 P89LPC932的初始化程序設計 25
4.5.2 主程序設計 25
第5章 結(jié)論 28
參考文獻 29
致謝 30
附錄 31