篇一：基于单片机毕业论文
内蒙古科技大学
本科生毕业设计说明书（毕业论文）
题 目：基于单片机的
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学 号：
专 业：自动化
班 级：
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PWM直流调速系统设计 06（4）
基于单片机的PWM直流调速系统设计
摘要
随着时代的进步和科技的发展，电机调速系统在工农业生产、交通运输以及日常生活中起着越来越重要的作用，因此，对电机调速的研究有着积极的意义.长期以来，直流电机被广泛应用于调速系统中，而且一直在调速领域占居主导地位。基于单片机的直流电机调速系统硬件电路的标准化程度高，制作成本低，且不受器件温度漂移的影响。其控制软件能够进行逻辑判断和复杂运算。系统的稳定性好，可靠性高。直流电动机具有优良的起、制动性能，宜于在广泛范围内平滑调速。在轧钢机、矿井卷机、挖掘机、金属切削机床、造纸机、高层电梯等领域中得到广泛应用。
本设计是基于单片机控制的PWM直流电机调速系统，系统以AT89C52单片机为核心，以2A、1000r/min小直流电机为控制对象，以L298N为H桥驱动芯片实现速度、电流反馈双闭环。采用PID控制算法，调节PWM 占空比从而控制电机两端电压，以达到调速的目的。用4*3键盘输入有关控制信号及参数，可以实现电机的启制动、正反转、速度调节。并在4位LED上实时显示输入参数及动态转速。
关键词：单片机、直流电机、PWM、 PID
Based on SCM PWM dc speed control system design
Abstract
With the progress of The Times and the development of science and technology, motor speed system in agricultural production, transportation and daily life plays a more and more important role in motor speed, therefore, the research has positive significance. For a long time, have been widely applied in dc motor control system, and has been inhabited areas in speed dominant. Based on SCM dc motor speed control system of high degree of standardization of hardware circuit, low cost, and the temperature drift. Device, The control software to logic and complex operation. The system has good stability and reliability. Dc motor with excellent, braking performance, and in a wide range smooth speed. In the mill, mine machine, excavator, metal cutting machine, paper machine, high-level elevator is widely used in the fields.
The design is based on single chip microcomputer control system of dc motor control PWM, by AT89C52 singlechip system, and 1000r/min small double-a dc motor to control, L298N H bridge to drive chip realize speed, double loop current feedback. PID control algorithm, regulate and control PWM occupies emptiescompared to achieve both voltage motor speed. Use 4 * 3 keyboard input signal and the relevant control parameters, can realize the rev brake motor speed regulation, and positive &negative. And in four LED on real-time display input parameters and dynamic speed.
Keywords ： monolithic integrated circuits, a direct motor，PWM，PID
目录
基于单片机的PWM直流调速系统设计 .................................................................... I 摘要................................................................................................................................ I Abstract ......................................................................................................................... II
第一章 绪论................................................................................................................ 1
1.1课题背景........................................................................................................... 1
1.2课题功能........................................................................................................... 1
第二章 系统硬件电路的设计...................................................................................... 2
2.1 系统总体设计................................................................................................... 2
2.1.1 系统总体设计框图................................................................................ 2
2.1.2单片机的选择及其简介......................................................................... 2
2.1.3 其他芯片简介........................................................................................ 6
2.2 PWM信号发生电路设计 ............................................................................. 19
2.2.1PWM的基本原理 .................................................................................... 19
2.2.2PWM信号发生电路设计 ................................................................. 20
2.2.3H桥芯片的工作原理..................................................................... 21
2.3 主电路设计..................................................................................................... 24
2.4 转速和电流的测量........................................................................................ 24
2.5 AD转换 ......................................................................................................... 26
2.6显示与键盘电路............................................................................................. 26
第三章 系统软件程序的设计.................................................................................... 28
3.1 PID控制算法原理及流程图 ........................................................................ 28
3.2 系统部分程序的设计……………………………………………………....29
3.2.1 单片机资源分配……………………………………………………...29
3.2.2 程序流程图.......................................................................................... 30
结论....................................................................................................................... 33
参考文献...................................................................................................................... 34
附录.............................................................................................................................. 35
致谢.............................................................................................................................. 48
第一章 绪论
1.1课题背景
随着时代的进步和科技的发展，电机调速系统在工农业生产、交通运输以及日常生活中起着越来越重要的作用，因此，对电机调速的研究有着积极的意义.长期以来，直流电机被广泛应用于调速系统中，而且一直在调速领域占居主导地位，这主要是因为直流电机不仅调速方便，而且在磁场一定的条件下，转速和电枢电压成正比，转矩容易被控制；同时具有良好的起动性能，能较平滑和经济地调节速度。因此采用直流电机调速可以得到良好的动态特性。由于直流电动机具有优良的起、制动性能，宜于在广泛范围内平滑调速。在轧钢机、矿井卷机、挖掘机、金属切削机床、造纸机、高层电梯等领域中得到广泛应用。近年来交流调速系统发展很快，然而直流控制系统毕竟在理论上和在时间上都比较成熟，而且从反馈闭环控制的角度来看，它又是交流系统的基础，长期以来，由于直流调速系统的性能指标优于交流调速系统。因此，直流调速系统一直在调速系统领域内占重要位置。
1.2课题功能
本论文介绍了基于AT89C52单片机来实现最优PID控制的直流脉冲（PWM）调速系统，并且详细论述了该系统的控制方法、结构、参数设计、程序设计等方面的问题。该系统结构简单，调速性能好，性能价格比高，真正实现了直流调速系统的高精度控制。
本设计是基于单片机控制的PWM直流电机调速系统，系统以AT89C52单片机为核心，以2A、1000r/min小直流电机为控制对象，L298N为H桥驱动芯片实现速度、电流反馈双闭环。采用PID控制算法，调节PWM 占空比从而控制电机两端电压，以达到调速的目的。用4*3键盘输入有关控制信号及参数，可以实现电机的启制动、正反转、速度调节。并在4位LED上实时显示输入参数及动态转速。
篇二：51单片机优秀毕业论文
泸 州 职 业 技 术 学 院
毕 业 论 文
基于单片机的进制换算
学生姓名
所 在 系 班 级 专 业
指导教师
2012年6月5日
XX XXXXX XXXX XXXXXX XXXXX
指导教师评阅书
评阅教师评阅书
教研室（或答辩小组）及教学系意见
泸州职业技术学院毕业论文目录
目录
摘要································································································································· 1 绪论································································································································· 2 课题背景 ····················································································································· 2 课题意义 ····················································································································· 2 程序扩展 ·········
第一章 系统功能及操作 ··································································································· 3
1.1系统功能的确定 ····································································································· 3
1.2 基本功能 ··············································································································· 9
1.3本章小结·············································································································· 10
第二章 系统模块介绍 ·····································································································11
2.1 主控模块 ··············································································································11 2. 2 引脚说明 ·············································································································11
2.3 主控模块设计 ······································································································ 13
2.3.1 电源电路模块设计························································································ 13
2.3.2 时钟电路模块设计························································································ 13
2.3.3 复位电路模块设计························································································ 14
2.4 LCD显示模块 ···································································································· 15 2. 5 按键模块 ············································································································ 17
第三章 系统硬件设计—实验板介绍 ··············································································· 19
3.1 硬件总图 ············································································································· 19
3.2主控硬件模块······································································································· 20
3.3按键硬件模块化 ··································································································· 21
3.4 LCD显示硬件模块化 ··························································································· 22
3.5本章小结·············································································································· 22
第四章 系统软件设计 ···································································································· 23 I
篇三：单片机本科毕业论文
青 岛 科 技 大 学
基于单片机的超声波测距系统设计 题 目 __________________________________
__________________________________
XXX 指导教师__________________________
XXX 辅导教师__________________________
XXX 学生姓名__________________________
090804XXX 学生学号__________________________
XXXXXXXX 092 班 信息科学与技术学院 院（部）____________________________ 专业______________________________________
2013 年 ___6 月 ___21 ______日
基于单片机的超声波测距系统设计
摘 要
超声波是一种指向性强，能量消耗缓慢，在介质中传播距离较远的声波，很
适合用于距离测量。目前国内一般是用专用集成电路设计超声波测距仪，但是成本高，没有显示，操作使用不方便，拓展不灵活。而基于单片机的超声波测距克服了上述缺点，所以应用非常广泛，这种设计要求非接触式测距。
本设计是以单片机技术为基础，实现对前方物体距离的测量。该系统设计主
要由主控制器模块、超声波发射模块、超声波接收模块和显示模块等四个基本模块构成，用接收部分接收超声波。本设计利用两个中断，在发射信号时，打开定时器中断0和外部中断0使定时器计时，接收到发射超声波信号时，外部中断0关闭中断，这时定时器中断0计录的时间就为超声波传播经过测距仪到前方物体的来回时间，经过单片机处理得到距离值S并且通过LCD1602显示出来。
本设计在室温条件下的精确度能达到3mm以内，但是要求被测量物体周围比
较空旷而且空气温度要求是室温精确度才会达到以上精度。
关键词：单片机，超声波传感器，LCD1602
The design of ultrasonic range finder based
on single chip microcomputer
ABSTRACT
Ultrasonic is a kind of strong directivity, energy consumption slow, in the medium
distance transmission of sound waves, very suitable for distance measurementAt present domestic general is to use ultrasonic rangefinder application-specific integrated circuit design, but the cost is high, no display, operation is not convenient, not flexible. The ultrasonic ranging based on single chip microcomputer to overcome the above shortcomings, so the application is very broad, this non-contact ranging design requirements.
This design is based on single chip microcomputer technology, realizes the
measurement of the front object distance. The system design is mainly composed of main controller module, ultrasonic launch module, ultrasonic receiving module and display module and so on four basic modules, with a receiving part receiving ultrasound. This design uses two interrupts, when transmitting, open the timer interrupt 0 timer and external interrupt 0 timer, receives the side of launch ultrasonic wave signal, the external interrupt 0 closed interrupted, then the timer interrupt 0 meter to record the time for the ultrasonic propagation through the range finder to the object in front of the time back and forth. And the result is treated with single chip microcomputer distance values S and through LCD1602 display.
This design at room temperature under the condition of precision can reach less
than 3 mm, but the request was required measure around an object is open and the air temperature is above room temperature will reach the precision accuracy.
KEY WORDS: single chip microcomputer; ultrasound sensor; LCD1602
目录
1 绪论 .......................................................... 5
1.1选题背景 ................................................. 5
1.2研究意义 ................................................. 5
2 超声波测距系统总体设计 ........................................ 7
2．1超声波测距系统设计的目的和要求 ........................... 7
2．2 超声波测距系统的工作原理 ................................ 7
3 超声波测距系统硬件设计 ........................................ 9
3.1 AT89S52单片机的概述 ...................................... 9
3.2 LCD1602液晶显示器 ....................................... 15
3.2.1 LCD1602模块的结构 ............................................ 15
3.2.2 LCD1602与单片机的连接方式 .................................... 17
3.3 HC-SR04超声波测距模块 ................................... 18
3.4 系统设计 ................................................ 20
4 超声波测距系统软件设计 ....................................... 23
4．1 设计原理图及分析 ....................................... 23
4．2 设计说明 ............................................... 24
5 超声波测距模块测试 ........................................... 27
6 结论 ......................................................... 28
1 绪论
1.1选题背景
由于超声波指向性强,能量消耗缓慢，在介质中传播的距离较远，因此它被广泛应用于距离的测试。使用超声波检测往往更快速，方便，计算简单，易于做到实时控制，并且在测量精度方面能达到工业使用的要求，测量时与被测物体无需直接接触，这些优点使其具有广泛的实际应用，被广泛应用于液位、井深、管道长度等测量。例如建筑施工单位的距离测量,汽车倒车防撞系统，潜艇超声波探头定位系统等[1]。
目前国内一般是用专用集成电路设计超声波测距仪，但是成本高，没有显示，操作使用不方便，拓展不灵活。而基于单片机的超声波测距克服了上述缺点，所以应用非常广泛，这种设计要求非接触式测距。本人设计了一个项目，该设计可广泛用于生活、军事等各个领域，该设计需要设计者有较好的数电、模电知识，并且具有一定的C语言编程能力，综合运用以上知识实现对超声波发射与接收信号进行控制、计算、处理，最后在LCD1602液晶显示器上显示。测量范围：2cm-400cm,测量精度3mm，不与被测物体直接接触测量，可显示清晰、稳定的测量结果。
1.2研究意义
在基于传统的测量距离存在不可克服的缺陷。例如，液面测量就是一种距离测量，传统的电极法是采用差位分布电极，通过给电或脉冲来检测液面，电极长期浸泡于水中或其他液体中，极易被腐蚀、电解，失去灵敏性。由于超声波具有强度大，方向性好等特点，利用超声波测量距离就可以解决这些问题。随着人们生活水平的提高，城市发展建设的加快，城市车辆逐渐增多，因为停车不当而造成的交通事故也越来越多。为了避免此类事故的发生，一个能够直观测出汽车与障碍物之间的距离的装置就变得十分重要。它可以及时将车辆与障碍物之间的距离反应出来，给司机以更准确的信息和更多的反应时间，减少事故的发生。此外，超声波测量距离技术还在工业控制、勘探测量、机器人定位和军事应用等领域得到了广泛的应用。
超声波测距电路可以由传统的模拟或者数字电路构建，但是基于这些传统电路构建的系统往往可靠性差，调试困难，可扩展性差，所以基于单片机的超声波测距系统被广泛的应用。通过简单的外围电路发生和接收超声波，单片机通过采