摘 要

直流电动机可以实现迅速启停，加减速和正反转，在工业和航空等领域有着非常广泛的应用。它具有交流电机等不具备的性能，诸如调速性能良好，静差率小，稳定性好，动态性能良好等特点。现代社会的生产不断扩大，自动化程度不断提高，传统上通过改变电枢回路电压来实现调速的方法已经无法达到所需调速要求， PWM脉宽调速技术应运而生。

本文将STC89C52单片机作为控制器，设计了一套基于上下位机结构的PWM脉宽调制的直流电机调速系统。上位机与下位机之间采用串行口通讯方式，上位机向单片机发送控制指令。单片机通过电机驱动电路，直接实现对直流电机启停、加减速和转动方向的控制，并通过LED指示灯和数码管，对直流电机的运动状态以及电机的速度所处的档位进行显示。

本设计的特色在于系统是基于上下位机结构，上位机使用串口调试助手发送控制命令，下位机使用单片机的独立按键进行控制，不仅小巧、轻便、而且操作简单，调试灵活，能够方便地实现人机交互，实时控制直流电机的状态。此外，系统采用PWM脉宽调速技术，能够实现大范围调速。

关键词：PWM调速；直流电机；单片机；串口通讯；

Design of DC Motor Control System

ABSTRACT

DC motors can achieve rapid start-stop, acceleration and deceleration, positive and negative inversion, and are widely used in industry and aviation. It has the characteristics that AC motors do not have, such as good speed control performance, low static error rate, good stability, good dynamic performance and so on. With the continuous expansion of production in modern society and the continuous improvement of automation, the traditional method of adjusting speed by changing armature circuit voltage has been unable to meet the required speed regulation requirements. PWM pulse width speed regulation technology emerged as the times require.

In this paper, STC89C52 single chip computer is used as the controller, and a PWM pulse width modulation DC motor speed regulation system based on the upper and lower computer structure is designed. The serial communication mode is adopted between the upper computer and the lower computer, and the upper computer sends control instructions to the single chip computer. Through the motor driving circuit, the MCU can directly control the starting and stopping, acceleration and deceleration and rotation direction of the DC motor, and display the movement state of the DC motor and the speed of the motor through the LED indicator lamp and digital tube.

The feature of this design is that the system is based on the structure of upper and lower computer. The upper computer uses serial debugging assistant to send control commands, and the lower computer uses independent keys of single chip computer to control. It is not only compact, portable, but also easy to operate and debug flexibly. It can easily realize human-computer interaction and real-time control of the state of DC motor. In addition, the system uses PWM pulse width speed regulation technology, which can achieve a wide range of speed regulation.

Key words：PWM Speed Regulation；DC Motor；Single-Chip microcomputer；Serial communication

目 录

1 绪论 - 1 -

1.1 研究目的及意义 - 1 -

1.2 直流电机调速系统研究现状 - 1 -

1.3 课题内容 - 2 -

2 PWM调速系统设计及原理 - 3 -

2.1 系统总体设计思路 - 3 -

2.2 PWM直流电机调速原理 - 3 -

3 硬件模块设计 - 5 -

3.1 硬件模块组成 - 5 -

3.2 主控制器模块 - 5 -

3.3 直流电机和驱动模块 - 7 -

3.4 按键控制模块 - 8 -

3.5 状态显示模块 - 9 -

4 程序设计 - 11 -

4.1 主程序设计 - 11 -

4.2 串口通信中断子程序 - 12 -

4.3 PWM信号发生中断子程序 - 15 -

4.4 按键检测子程序 - 16 -

4.5 直流电机控制子程序 - 20 -

4.6 LED显示子程序 - 21 -

4.7数码管显示子程序 - 21 -

5 系统调试 - 22 -

5.1仿真结果分析 - 22 -

5.2实物调试结果 - 25 -

结 论 - 28 -

致 谢 - 29 -

参考文献 - 30 -

附录A:Proteus仿真原理图 - 31 -

1 绪论

1.1 研究目的及意义

直流电动机的发明时间最早，并且它一经发明便在生产中得到了广泛使用。它可以实现迅速启停，加减速和正反转，在工业和航空等领域得到广泛的应用^[1]。直流电机还具有交流电机等不具备的性能，诸如调速性能良好，静差率小，稳定性好，动态性能良好等特点^[2]。

现代社会的生产不断扩大，自动化程度不断提高，传统上通过改变电枢回路电压来实现调速的方法已经无法达到所需调速要求，由此调速技术开始产生并且不断发展壮大^[3]。与此同时，电子技术日新月异，电机的调速技术也逐步由传统的模拟化的技术向数字化的技术转变。尤其是单片机应用到直流电机的调速中之后，调速技术更是发展到一个新的阶段，各种控制系统都在不断向着智能化和高可靠性转变^[4]。

1.2 直流电机调速系统研究现状