毕业设计（论文）-基于AT89C51单片机控制的双闭环直流调速系统设计精选.doc

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PWM直流电机调速系统，系统以STC89C51单片机为核心，以130小直流电机为控制对象，以L298N为H桥驱动芯片实现电动机的转速反馈控制。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*4键盘输入有关控制信号及参数，并在12864 LED上实时显示输入参数及动态转速。系统的硬件设计部分包括按键模块、电动机驱动模块、STC89C51单片机系统、光电门测速模块、保护电路、供电电源和直流电机。系统的软件部分包括键盘控制程序设计、显示程序设计、主控程序设计。整个系统实现了单片机控制电机的启制动、正反转、速度调节的效果。 关键词：STC89C51单片机；直流电机；PWM ；占空比 Abstract With the progress of the times and the development of science and technology, motor speed control system in the industrial and agricultural production, transportation and daily life plays an increasingly important role, therefore, the study of motor speed has a positive meaning. Long-term since, the DC motor is widely used in the control system, and has been in control field to dominate. The design is based on the single chip microcomputer control of PWM DC motor speed control system, the system uses STC89C51 single chip microcomputer as the core, with 130small DC motor as control object, with L298N H bridge driver chip to realize the motor speed feedback control. Regulation of the PWM duty cycle to control the motor voltage at both ends, so as to achieve the purpose of speed. With 4*4 keyboard input control signal and parameters, and in 12864LED real-time display input parameters and dynamic speed. System hardware design part comprises a key module, motor drive module, STC89C51 singlechip system, photoelectric door gun module, protection circuit, power supply and a DC motor. System software includes keyboard control program design, program design, main control program design. The entire system to achieve the single-chip microcomputer to control the motor start and brake, reverse, speed regulating effect. Keywords ：STC89C51 single chip microcomputer；DC motor；PWM；Duty ratio 目 录 摘 要 I Abstract II 1 引言 1 1.1 直流调速系统概况 1 1.2 设计目的和意义 2 1.3 3 1.4 设计要求和内容 3 2 直流调速原理分析与方案确定 4 2.1 直流PWM调速系统原理分析 4 2.2 方案论证和选择 6 3 系统硬件设计 10 3.1 按键控制模块 10 3.2 电动机驱动模块 11 3.4 STC89C51单片机